WorldWideScience

Sample records for current tectonic activity

  1. Studies in geophysics: Active tectonics

    Science.gov (United States)

    1986-01-01

    Active tectonics is defined within the study as tectonic movements that are expected to occur within a future time span of concern to society. Such movements and their associated hazards include earthquakes, volcanic eruptions, and land subsidence and emergence. The entire range of geology, geophysics, and geodesy is, to some extent, pertinent to this topic. The needs for useful forecasts of tectonic activity, so that actions may be taken to mitigate hazards, call for special attention to ongoing tectonic activity. Further progress in understanding active tectonics depends on continued research. Particularly important is improvement in the accuracy of dating techniques for recent geologic materials.

  2. Advances on Active Tectonics Research

    Institute of Scientific and Technical Information of China (English)

    Chen Yong; Chen Qifu; Li Juan

    2001-01-01

    The tectonic movement at human scale has not been fully understood yet, especially for active tectonics, although it is the basis to study natural hazards and environmental variations. Many national and international scientific plans related closely to active tectonics research have been made in the past ten years. This paper briefly summarized the background of the undertaking of active tectonics research, its advances and existing problems, and the key points in its future studies are also pointed out. The emerging of new technologies like the Earth Observing Sys tem, Digital Seismology and so on provides unusual opportunities for tectonic research. It is emphasized, however, that careful analyses and building up of new theoretical frame are sill the key problems for studies of active tectonics, especially for active tectonics in China' s conti nent.

  3. Basic characteristics of active tectonics of China

    Institute of Scientific and Technical Information of China (English)

    DENG; Qidong(邓起东); ZHANG; Peizhen(张培震); RAN; Yongkang(冉勇康); YANG; Xiaoping(杨晓平); MIN; Wei(闵伟); CHU; Quanzhi(楚全芝)

    2003-01-01

    During the last 20 years, studies on active tectonics in China have entered a new quantitative research stage and made a great progress. Summing up the quantitative results, a Map of Active Tectonics of China on the scale of 1︰4 million has been compiled. In the map all types of active tectonics and their kinematic parameters are reflected in possible detail, such as active faults, active folds, active basins, active blocks, volcanoes, and earthquakes. This paper summarizes the basic characteristics of active tectonics of China. The Himalaya Mountains and Taiwan Island are major plate boundaries where the slip rates are larger than 15 mm/a. Tectonic activity in the continental intraplate region is characterized by block motion. The crust and lithosphere in the region were dissected into blocks with different orders. Of them the Qinghai-Xizang (Tibet), Xin- jiang, and North China block regions exhibit the most recent tectonic activity. The kinematic characteristics of more than 200 active tectonic zones indicate that the intraplate tectonic activity represents a block motion at a limited low rate. Horizontal slip rate along the tectonic boundary belts between the blocks is generally less than 10 mm/a, and 10-15 mm/a in maximum, and hence it does not support the continental escape theory of high rate of slip.

  4. Current tectonic deformation and seismogenic characteristics along the northeast margin of Qinghai-Xizang block*

    Institute of Scientific and Technical Information of China (English)

    王双绪; 江在森; 张希; 陈文胜

    2002-01-01

    Based on the data from repeated precise leveling and across-fault deformation measurements carried out in recent 30 years and the analyzed results from GPS observations made in recent years along the northeastern margin of Qinghai(Xizang block, and combined with the geological structures and seismic activities, some characteristics in regional tectonic deformation and strong earthquake development are studied and approached preliminarily. The results show that: a) The space-time distribution of current tectonic deformation in this area is inhomogeneous with relatively intensive tectonic deformation in the vicinity of main boundary faults and weak deformation in the farther areas. The intensity of vertical differential movement and the deformation status vary with time, and the horizontal movement and deformation are characterized by apparent compression and strike-slip. b) The tectonic stress field generated by the NE-trending continuous compressive movement of Qinghai(Xizang block due to the northward press and collision of India plate is the principal stress for the tectonic deformation and earthquake development in this area. The evolution of space-time distribution of tectonic deformation and seismicity is closely related to the block activity and dynamic evolution of regional tectonic stress field. c) The vertical deformation uplift and high-gradient deformation zones and the obvious fault deformation anomaly appeared along the boundaries of tectonic blocks can be considered as the indicators of hindered block motion and intensified tectonic stress field for strong earthquake development. Usually, the above-mentioned phenomena would be followed by the seismicity of M(6.0, but the earthquake might not occur in the place with the maximum movement. The zones with the fault deformation anomaly characterized by (tendencious accumulation acceleration turning( and the surrounding areas might be the positions for accumulation of strain energy and development and

  5. Vertical tectonics at an active continental margin

    Science.gov (United States)

    Houlié, N.; Stern, T. A.

    2017-01-01

    Direct observations of vertical movements of the earth's surface are now possible with space-based GPS networks, and have applications to resources, hazards and tectonics. Here we present data on vertical movements of the Earth's surface in New Zealand, computed from the processing of GPS data collected between 2000 and 2015 by 189 permanent GPS stations. We map the geographical variation in vertical rates and show how these variations are explicable within a tectonic framework of subduction, volcanic activity and slow slip earthquakes. Subsidence of >3 mm/yr is observed along southeastern North Island and is interpreted to be due to the locked segment of the Hikurangi subduction zone. Uplift of 1-3 mm/yr further north along the margin of the eastern North Island is interpreted as being due to the plate interface being unlocked and underplating of sediment on the subduction thrust. The Volcanic Plateau of the central North Island is being uplifted at about 1 mm/yr, which can be explained by basaltic melts being injected in the active mantle-wedge at a rate of ∼6 mm/yr. Within the Central Volcanic Region there is a 250 km2 area that subsided between 2005 and 2012 at a rate of up to 14 mm/yr. Time series from the stations located within and near the zone of subsidence show a strong link between subsidence, adjacent uplift and local earthquake swarms.

  6. A Digital Tectonic Activity Map of the Earth

    Science.gov (United States)

    Lowman, Paul; Masuoka, Penny; Montgomery, Brian; OLeary, Jay; Salisbury, Demetra; Yates, Jacob

    1999-01-01

    The subject of neotectonics, covering the structures and structural activity of the last 5 million years (i.e., post-Miocene) is a well-recognized field, including "active tectonics," focussed on the last 500,000 years in a 1986 National Research Council report of that title. However, there is a cartographic gap between tectonic maps, generally showing all features regardless of age, and maps of current seismic or volcanic activity. We have compiled a map intended to bridge this gap, using modern data bases and computer-aided cartographic techniques. The maps presented here are conceptually descended from an earlier map showing tectonic and volcanic activity of the last one million years. Drawn by hand with the National Geographic Society's 1975 "The Physical World" map as a base, the 1981 map in various revisions has been widely reproduced in textbooks and various technical publications. However, two decades of progress call for a completely new map that can take advantage of new knowledge and cartographic techniques. The digital tectonic activity map (DTM), presented in shaded relief (Fig. 1) and schematic (Fig. 2) versions, is the result. The DTM is intended to show tectonism and volcanism of the last one million years, a period long enough to be representative of global activity, but short enough that features such as fault scarps and volcanos are still geomorphically recognizable. Data Sources and Cartographic Methods The DTM is based on a wide range of sources, summarized in Table 1. The most important is the digital elevation model, used to construct a shaded relief map. The bathymetry is largely from satellite altimetry, specifically the marine gravity compilations by Smith and Sandwell (1996). The shaded relief map was designed to match the new National Geographic Society world physical map (1992), although drawn independently, from the digital elevation model. The Robinson Projection is used instead of the earlier Van der Grinten one. Although neither

  7. Problems of the active tectonics of the Eastern Black Sea

    Science.gov (United States)

    Javakhishvili, Z.; Godoladze, T.; Dreger, D. S.; Mikava, D.; Tvaliashvili, A.

    2016-12-01

    The Black Sea Basin is the part of the Arabian Eurasian Collision zone and important unit for understanding the tectonic process of the region. This complex basin comprises two deep basins, separated by the mid-Black Sea Ridge. The basement of the Black Sea includes areas with oceanic and continental crust. It was formed as a "back-arc" basin over the subduction zone during the closing of the Tethys Ocean. In the past decades the Black Sea has been the subject of intense geological and geophysical studies. Several papers were published about the geological history, tectonics, basement relief and crustal and upper mantle structure of the basin. New tectonic schemes were suggested (e. g. Nikishin et al 2014, Shillington et al. 2008, Starostenko et al. 2004 etc.). Nevertheless, seismicity of the Black Sea is poorly studied due to the lack of seismic network in the coastal area. It is considered, that the eastern basin currently lies in a compressional setting associated with the uplift of the Caucasus and structural development of the Caucasus was closely related to the evolution of the Eastern Black Sea Basin. Analyses of recent sequence of earthquakes in 2012 can provide useful information to understand complex tectonic structure of the Eastern Black Sea region. Right after the earthquake of 2012/12/23, National Seismic monitoring center of Georgia deployed additional 4 stations in the coastal area of the country, close to the epicenter area, to monitor aftershock sequence. Seismic activity in the epicentral area is continuing until now. We have relocated approximately 1200 aftershocks to delineate fault scarf using data from Georgian, Turkish and Russian datacenters. Waveforms of the major events and the aftershocks were inverted for the fault plane solutions of the events. For the inversion were used green's functions, computed using new 1D velocity model of the region. Strike-slip mechanism of the major events of the earthquake sequence indicates extensional

  8. Plate tectonics and planetary habitability: current status and future challenges.

    Science.gov (United States)

    Korenaga, Jun

    2012-07-01

    Plate tectonics is one of the major factors affecting the potential habitability of a terrestrial planet. The physics of plate tectonics is, however, still far from being complete, leading to considerable uncertainty when discussing planetary habitability. Here, I summarize recent developments on the evolution of plate tectonics on Earth, which suggest a radically new view on Earth dynamics: convection in the mantle has been speeding up despite its secular cooling, and the operation of plate tectonics has been facilitated throughout Earth's history by the gradual subduction of water into an initially dry mantle. The role of plate tectonics in planetary habitability through its influence on atmospheric evolution is still difficult to quantify, and, to this end, it will be vital to better understand a coupled core-mantle-atmosphere system in the context of solar system evolution. © 2012 New York Academy of Sciences.

  9. Relief Evolution in Tectonically Active Mountain Ranges

    Science.gov (United States)

    Whipple, Kelin X.

    2004-01-01

    The overall aims of this 3-yr project, as originally proposed were to: (1) investigate quantitatively the roles of fluvial and glacial erosion in the evolution of relief in mountainous regions, and (2) test rigorously the quality and accuracy of SRTM topographic data in areas of rugged relief - both the most challenging and of greatest interest to geomorphic, neotectonic, and hazards applications. Natural laboratories in both the western US and the Southern Alps of New Zealand were identified as most promising. The project has been both successful and productive, despite the fact that no SRTM data for our primary field sites in New Zealand were released on the time frame of the work effort. Given the delayed release of SRTM data, we pursued the scientific questions of the roles of fluvial and, especially, glacial erosion in the evolution of relief in mountainous regions using available digital elevation models (DEMs) for the Southern Alps of New Zealand (available at both 25m and 50m pixel sizes), and USGS 10m and 30m DEMs within the Western US. As emphasized in the original proposal, we chose the emphasis on the role of glacial modification of topographic relief because there has been little quantitative investigation of glacial erosion processes at landscape scale. This is particularly surprising considering the dramatic sculpting of most mid- and high-latitude mountain ranges, the prodigious quantities of glacially-derived sediment in terrestrial and marine basins, and the current cross-disciplinary interest in the role of denudational processes in orogenesis and the evolution of topography in general. Moreover, the evolution of glaciated landscapes is not only a fundamental problem in geomorphology in its own right, but also is at the heart of the debate over Late Cenozoic linkages between climate and tectonics.

  10. The Current Tectonics of the Yukon and Adjacent Area

    Science.gov (United States)

    Hyndman, R. D.; Leonard, L. J.

    2014-12-01

    The current tectonics across the Yukon and adjacent areas of western Northwest Territories (NWT) and northern British Columbia appear to be driven primarily by the Yakutat Terrane collision, an "indenter" in the corner of the Gulf of Alaska. GPS data show 1-10 mm/yr northward and eastward, decreasing inland. The rates from earthquake statistics are similar although there are important discrepancies. The eastern Cordillera earthquake mechanisms are mainly thrust in the Mackenzie Mountains of southwestern NWT where the Cordillera upper crust is overthrusting the craton. To the north, the mechanisms are mainly strike-slip in the Richardson Mountains that appear to lie along the edge of the craton. The deformation appears to be limited to the hot and weak Cordillera with the strong craton providing an irregular eastern boundary. For example, there is an eastward bow in the craton edge and the deformation in the Mackenzie Mountains. On the Beaufort Sea margin in the region of the Mackenzie Delta there appears to be a type of "subduction zone" with the continent very slowly overthrusting the oceanic plate, a process that has continued since at least the Cretaceous. A northward moving continental margin block is bounded by left lateral faulting in the west (Canning Displacement Zone of eastern Alaska) and right lateral faulting in the east (Richardson Mountains in eastern Yukon). There is almost no seismicity on this thrust belt but as for some other subduction zones such as Cascadia there is the potential for very infrequent great earthquakes.

  11. Active Tectonics Revealed by River Profiles along the Puqu Fault

    OpenAIRE

    Ping Lu,; Yu Shang

    2015-01-01

    The Puqu Fault is situated in Southern Tibet. It is influenced by the eastward extrusion of Northern Tibet and carries the clockwise rotation followed by the southward extrusion. Thus, the Puqu Fault is bounded by the principal dynamic zones and the tectonic evolution remains active alongside. This study intends to understand the tectonic activity in the Puqu Fault Region from the river profiles obtained from the remotely sensed satellite imagery. A medium resolution Digital Elevation Model (...

  12. Active Tectonics Revealed by River Profiles along the Puqu Fault

    Directory of Open Access Journals (Sweden)

    Ping Lu

    2015-04-01

    Full Text Available The Puqu Fault is situated in Southern Tibet. It is influenced by the eastward extrusion of Northern Tibet and carries the clockwise rotation followed by the southward extrusion. Thus, the Puqu Fault is bounded by the principal dynamic zones and the tectonic evolution remains active alongside. This study intends to understand the tectonic activity in the Puqu Fault Region from the river profiles obtained from the remotely sensed satellite imagery. A medium resolution Digital Elevation Model (DEM, 20 m was generated from an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER stereo pair of images and the stream network in this region was extracted from this DEM. The indices of slope and drainage area were subsequently calculated from this ASTER DEM. Based on the stream power law, the area-slope plots of the streams were delineated to derive the indices of channel concavity and steepness, which are closely related to tectonic activity. The results show the active tectonics varying significantly along the Puqu Fault, although the potential influence of glaciations may exist. These results are expected to be useful for a better understanding of tectonic evolution in Southeastern Tibet.

  13. Active tectonics coupled to fluvial erosion in the NW Himalaya

    Science.gov (United States)

    Vannay, J.-C.; Grasemann, B.; Rahn, M.; Frank, W.; Carter, A.

    2003-04-01

    Both syntaxial extremities of the Himalaya show a spatial correlation between active exhumation of deep crustal rocks and the presence of powerful rivers, the Indus and the Tsangpo-Brahmaputra, cutting across the range two of the deepest gorges on Earth. These features strongly suggests that vigorous fluvial erosion can locally enhance isostatic and tectonic uplift, which in turn contributes to heat advection and weakening of the crust, as well as to maintain steep topographic gradients [Zeitler et al., 2001]. In order to test this positive feedback model, we combined structural and geochronological data to constrain the tectono-thermal evolution along the Sutlej (NW India), the third largest river cross-cutting entirely the Himalaya. The Himalayan crystalline core zone exposed along the Sutlej Valley is composed of two gneiss sheets, that were successively underthrusted and tectonically extruded as a consequence of the foreland-directed propagation of deformation in the Indian plate margin. During Early to Middle Miocene, combined thrusting along the Main Central Thrust (MCT) and extension along the Sangla Detachment induced the rapid exhumation and cooling of the amphibolite facies to migmatitic High Himalayan Crystalline Sequence [Vannay &Grasemann, 2001]. Underthrusting beneath the MCT led to the creation of the amphibolite facies Lesser Himalayan Crystalline Sequence (LHCS). The LHCS cooled rapidly from Late Miocene to Pleistocene, as a consequence of tectonic extrusion controlled by thrusting along the Munsiari Thrust, and extension in the MCT hanging wall. This phase is still active, as indicated by: (1) cooling rates in excess of 100^oC/Myr during the past ˜3 Myr in the LHCS; (2) Holocene neo-tectonic activity; (3) present-day hydrothermal activity testifying to elevated near-surface geothermal gradients; and (4) seismic activity along the Munsiari Thrust. Modelling of fluvial erosion in the Himalaya indicate that the Sutlej Valley corresponds to the main

  14. Crustal structure and active tectonics in the Eastern Alps

    DEFF Research Database (Denmark)

    Brückl, E.; Behm, M.; Decker, K.

    2010-01-01

    During the last decade, a series of controlled source seismic experiments brought new insight into the crustal and lithospheric structure of the Eastern Alps and their adjacent tectonic provinces. A fragmentation of the lithosphere into three blocks, Europe (EU), Adria (AD), and the new Pannonian...... fragment (PA), was interpreted and a triple junction was inferred. The goal of this study has been to relate these deep crustal structures to active tectonics. We used elastic plate modeling to reconsider the Moho fragmentation. We interpret subduction of EU below AD and PA from north to south...... and underthusting of AD mantle below PA from southwest to northeast. The Moho fragmentation correlates well with major upper crustal structures and is supported by gravity, seismic, and geodetic data. An analysis of crustal thickening suggests that active convergence is associated with continued thrusting...

  15. Measurements of Active Tectonic Deformation on the Guerrero Coast, Mexico

    Science.gov (United States)

    Ramirez, T.; Cundy, A.; Carranza-Edwards, A.; Morales, E.; Kostoglodov, V.; Urrutia-Fucugauchi, J.

    2004-12-01

    The study of tectonic deformation rates using displaced shoreline features is relatively well-established, and has provided much useful information on seismic hazard. Such studies have frequently been complemented by analysis of the coastal sedimentary record, where past marine to terrestrial environmental changes (and vice versa) may be recorded by clear changes in stratigraphy. Studies of this type are particularly valuable for tectonically-active areas where the preservation of former shoreline features is poor, or where long-term subsidence has resulted in their erosion, drowning or burial. The specific objective of this study is to derive rates of tectonic deformation from geomorphic and stratigraphic studies of the Guerrero coastal area, and to examine the feasibility of this stratigraphic approach in the coastal lagoons of the Mexican Pacific coast, in the Guerrero gap. The Guerrero gap coastal area, where a major earthquake is expected to occur, parallels the Cocos plate subduction zone. Here convergence rates vary from 5.2 cm/yr to 5.8 cm/yr. The Guerrero gap has experienced several historical earthquakes, notably the 1911 (7.8 Ms). However, no large magnitude events since the 1911 earthquake and only a few Ms~6 events have occurred near the Guerrero gap edges. It is expected that a major interplate earthquake of estimated magnitude Mw=8.1 to 8.4 has a high probability to occur. Landforms within the Guerrero gap indicate that the coast is subsiding. A series of key indicators such as elongated islands reminiscent of ancient barriers, submerged barriers island, extensive marshy environments, increased depths in the lagoons, and submerged anthropogenic features (shell mounds), among others, suggest active tectonic subsidence of the coast. In contrast, the adjacent northwest area off the Guerrero gap exhibits landforms characteristic of tectonic uplift (marine terraces and uplifted beach ridges), indicating a different seismo-tectonic regime northwest of the

  16. Active tectonics and earthquake potential of the Myanmar region

    Science.gov (United States)

    Wang, Yu; Sieh, Kerry; Tun, Soe Thura; Lai, Kuang-Yin; Myint, Than

    2014-04-01

    This paper describes geomorphologic evidence for the principal neotectonic features of Myanmar and its immediate surroundings. We combine this evidence with published structural, geodetic, and seismic data to present an overview of the active tectonic architecture of the region and its seismic potential. Three tectonic systems accommodate oblique collision of the Indian plate with Southeast Asia and extrusion of Asian territory around the eastern syntaxis of the Himalayan mountain range. Subduction and collision associated with the Sunda megathrust beneath and within the Indoburman range and Naga Hills accommodate most of the shortening across the transpressional plate boundary. The Sagaing fault system is the predominant locus of dextral motion associated with the northward translation of India. Left-lateral faults of the northern Shan Plateau, northern Laos, Thailand, and southern China facilitate extrusion of rocks around the eastern syntaxis of the Himalaya. All of these systems have produced major earthquakes within recorded history and continue to present major seismic hazards in the region.

  17. Active Tectonics: Part 2: Epeirogenic and intraplate movements

    Science.gov (United States)

    Brown, L. D.; Reilinger, R. E.

    The major deformations of the Earth's surface are largely consistent with the tenets of plate tectonics, which predict that such activity should be focused at the various boundaries along which massive lithospheric plates collide, pull apart, or slide past one another. Yet crustal deformations also occur well into the interior of these plates. Some may represent the distributed effects of distant plate boundaries, as, for example, the earthquakes of the intermontane western United States. Some, such as the geodetically observed uplift over a deep magma chamber in the Rio Grande rift of New Mexico, may correspond to incipient foundation of a new plate boundary. Others, like the subtle, broad uplifts and subsidences in the nominally stable cratonic interiors, are much more puzzling. Such motions often appear estranged, if not divorced, from accepted plate-tectonic processes. Postglacial rebound, a well-known phenomenon in portions of North America and Europe, also appears to be an inadequate explanation for many observations. Understanding contemporary motions of plate interiors is often hindered by the paucity and uncertain accuracy of relevant geophysical and geodetic observations. Yet intraplate tectonics constitutes more than a scientific enigma. Even seemingly slow vertical motions may threaten river courses or seafront properties on socially relevant time scales, and the subtle strain accumulating elsewhere may portend future earthquakes or volcanoes in the least predictable places.

  18. Tectonic and Hydrothermal Activities in Debagh, Guelma Basin (Algeria

    Directory of Open Access Journals (Sweden)

    Said Maouche

    2013-01-01

    Full Text Available Quaternary and Pliocene travertines, deposited from hot springs, can reveal much about neotectonic and hydrothermal activity. The aim of this work is the understanding of the actual tectonic activity in the Guelma Basin and in one of its spa structures. Gravity data were collected during a field study in the Hammam Debagh (HD area and then analyzed to better highlight the architecture of its subsurface underlying structures. This analysis was performed by means of a Bouguer anomaly, upward continuations, and residual and derivative maps. Comparison of gravity maps, field geology, geomorphic observations, and structural maps allowed us to identify the major structural features in the Hammam Debagh. As a result, we confirm the position of the Hammam Debagh active fault which is superimposed to the hydrothermal active source in the NW-SE direction characterized by a negative gravity anomaly.

  19. Tectonic geomorphology

    National Research Council Canada - National Science Library

    Burbank, Douglas West; Anderson, Robert S

    2012-01-01

    Tectonic geomorphology is the study of the interplay between tectonic and surface processes that shape the landscape in regions of active deformation and at times scales ranging from days to millions of years...

  20. Drilling to investigate processes in active tectonics and magmatism

    Science.gov (United States)

    Shervais, J.; Evans, J.; Toy, V.; Kirkpatrick, J.; Clarke, A.; Eichelberger, J.

    2014-12-01

    Coordinated drilling efforts are an important method to investigate active tectonics and magmatic processes related to faults and volcanoes. The US National Science Foundation (NSF) recently sponsored a series of workshops to define the nature of future continental drilling efforts. As part of this series, we convened a workshop to explore how continental scientific drilling can be used to better understand active tectonic and magmatic processes. The workshop, held in Park City, Utah, in May 2013, was attended by 41 investigators from seven countries. Participants were asked to define compelling scientific justifications for examining problems that can be addressed by coordinated programs of continental scientific drilling and related site investigations. They were also asked to evaluate a wide range of proposed drilling projects, based on white papers submitted prior to the workshop. Participants working on faults and fault zone processes highlighted two overarching topics with exciting potential for future scientific drilling research: (1) the seismic cycle and (2) the mechanics and architecture of fault zones. Recommended projects target fundamental mechanical processes and controls on faulting, and range from induced earthquakes and earthquake initiation to investigations of detachment fault mechanics and fluid flow in fault zones. Participants working on active volcanism identified five themes: the volcano eruption cycle; eruption sustainability, near-field stresses, and system recovery; eruption hazards; verification of geophysical models; and interactions with other Earth systems. Recommended projects address problems that are transferrable to other volcanic systems, such as improved methods for identifying eruption history and constraining the rheological structure of shallow caldera regions. Participants working on chemical geodynamics identified four major themes: large igneous provinces (LIPs), ocean islands, continental hotspot tracks and rifts, and

  1. Current regional stress field and the resultant crustal deformation in SE Korea and their tectonic implication

    Science.gov (United States)

    Kim, M. C.; Cho, H.; Son, M.

    2014-12-01

    To determine current regional stress field and to characterize the resultant crustal deformation in SE Korea, Quaternary fault, focal mechanism, and geotechnical in-situ stress data were synthetically analyzed. The Quaternary faults are extensively observed along major inherited fault zones and show compatible orientations with general trends of the inherited faults. Most of the Quaternary faults have a top-to-the-west thrust geometry and kinematics and show a tendency of upward-decreasing dip angle and upward-narrowing gouge zone. Slip-sense indicators and paleo-stress field reconstructions indicate that the faults resulted from reverse or transpressional faulting under an E-W compression. All the magnetic fabrics (AMS) of the fault gouges also indicate the prevailing reverse-slip faulting under an ENE-WNW compression. The dominant oblate magnetic fabrics parallel to fault plane and the degrees of anisotropy increasing in proportion to their oblatenesses indicate that the fabrics have formed by a progressive deformation due to continuous simple shear during the last reactivation stage as reverse faulting. The focal mechanism study in and around the Korean Peninsula show the horizontally clustered P-axes in ENE-WSW direction and the girdle-distributed T-axes in NNW trend. The geotechnical in-situ stress data in south Korea also show NE- or ENE-trending maximum horizontal stress. The current crustal deformation in Korea thus can be characterized by contractional structures produced under a regional E-W or ENE-WSW compression stress field, and most of the Quaternary faults resulted from the local re-activation of appropriately oriented inherited major faults. Considering the tectonic setting and structural features in Asia during the Neogene, the current stress regime is interpreted to have been caused by the cooperation of westward shallow subduction of Pacific Plate and collision of Indian and Eurasian continents since about 5-3.5 Ma.

  2. Areas of Unsolved Problems in Caribbean Active Tectonics

    Science.gov (United States)

    Mann, P.

    2015-12-01

    I review some unsolved problems in Caribbean active tectonics. At the regional and plate scale: 1) confirm the existence of intraplate deformation zones of the central Caribbean plate that are within the margin of error of ongoing GPS measurements; 2) carry out field studies to evaluate block models versus models for distributed fault shear on the densely populated islands of Jamaica, Hispaniola, Puerto Rico, and the Virgin Islands; 3) carry out paleoseismological research of key plate boundary faults that may have accumulated large strains but have not been previously studied in detail; 4) determine the age of onset and far-field effects of the Cocos ridge and the Central America forearc sliver; 4) investigate the origin and earthquake-potential of obliquely-sheared rift basins along the northern coast of Venezuela; 5) determine the age of onset and regional active, tectonic effects of the Panama-South America collision including the continued activation of the Maracaibo block; and 6) validate longterm rates on active subduction zones with improving, tomographic maps of subducted slabs. At the individual fault scale: 1) determine the mode of termination of large and active strike -slip faults and application of the STEP model (Septentrional, Polochic, El Pilar, Bocono, Santa Marta-Bucaramanaga); 2) improve the understanding of the earthquake potential on the Enriquillo-Plantain Garden fault zone given "off-fault" events such as the 2010 Haiti earthquake; how widespread is this behavior?; and 3) estimate size of future tsunamis from studies of historic or prehistoric slump scars and mass transport deposits; what potential runups can be predicted from this information?; and 4) devise ways to keep rapidly growing, circum-Caribbean urban populations better informed and safer in the face of inevitable and future, large earthquakes.

  3. Relative tectonic activity classification in Kermanshah area, west Iran

    Directory of Open Access Journals (Sweden)

    M. Arian

    2014-07-01

    Full Text Available The High Zagros region because of closing to subduction zone and the collision of the Arabian and Eurasian plates is imposed under the most tectonic variations. In this research, Gharasu river basin that it has located in Kermanshah area was selected as the study area and 6 geomorphic indices were calculated and the results of each ones were divided in 3 classes. Then, using the indices, relative tectonic activity was calculated and the values were classified and analyzed in 4 groups. Regions were identified as very high, high, moderate and low. In analyzing the results and combining them with field observation and regional geology the results are often associated and justified with field evidences. The highest value is located on Dokeral anticline in crush zone in Zagros Most of the areas with high and moderate values of lat are located on crush zone in Zagros too. Crushing of this zone is because of main faults mechanism of Zagros region. The result of this paper confirms previous researches in this region. At the end of the eastern part of the study area, the value of Iat is high that could be the result of Sarab and Koh-e Sefid faults mechanism.

  4. Activities for Plate Tectonics using GeoMapApp

    Science.gov (United States)

    Goodwillie, A. M.

    2016-12-01

    The concept of plate tectonics is a fundamental component of our understanding of how Earth works yet authentic, high-quality geoscience data related to plate tectonics may not be readily available to all students. To compound matters, when data is accessible, students may not possess the skills or resources necessary to explore and analyse it. As a result, much emphasis at federal and state level is now placed upon encouraging students to work with more data and more technology more often and more rigourously. Easy-to-use digital platforms offer much potential for promoting inquiry-based learning at all levels of education. GeoMapApp is one such tool. Developed at Columbia University's Lamont-Doherty Earth Observatory, GeoMapApp (http://www.geomapapp.org) is a free resource that integrates a wide range of research-grade geoscience data in one intuitive map-based interface. Simple strategies for data manipulation, visualisation and presentation allow uses to explore the data in meaningful ways. Layering and transparency capabilities further allow learners to use GeoMapApp to compare multiple data sets at once, and high-impact Save Session functionality allows a GeoMapApp project to be saved for sharing or later use. In this presentation, activities related to plate tectonics will be highlighted. One GeoMapApp activity helps students investigate plate boundaries by exploring earthquake and volcano locations. Another requires students to calculate the rate of seafloor spreading using crustal age data in various ocean basins. A third uses the GeoMapApp layering technique to explore the influence of geological forces in shaping the landscape. Each activity shown can be done by students on an individual basis, as pairs, or as groups. Educators report that student use of GeoMapApp fosters an increased sense of data "ownership" amongst students, promotes STEM skills, and provides them with access to authentic research-grade geoscience data using the same cutting

  5. Glacial reorganization of topography in a tectonically active mountain range

    Science.gov (United States)

    Adams, Byron; Ehlers, Todd

    2016-04-01

    Tests of the interactions between tectonic and climate forcing on Earth's topography often focus on the concept of steady-state whereby processes of rock deformation and erosion are opposing and equal. However, when conditions change such as the climate or tectonic rock uplift, then surface processes act to restore the balance between rock deformation and erosion by adjusting topography. Most examples of canonical steady-state mountain ranges lie within the northern hemisphere, which underwent a radical change in the Quaternary due to the onset of widespread glaciation. The activity of glaciers changed erosion rates and topography in many of these mountain ranges, which likely violates steady-state assumptions. With new topographic analysis, and existing patterns of climate and rock uplift, we explore a mountain range previously considered to be in steady-state, the Olympic Mountains, USA. The details of our analysis suggest the dominant topographic signal in the Olympic Mountains is a spatial, and likely temporal, variation in erosional efficiency dictated by orographic precipitation, and Pleistocene glacier ELA patterns, and not tectonic rock uplift rates. Alpine glaciers drastically altered the relief structure of the Olympic Mountains. The details of these relief changes are recorded in channel profiles as overdeepenings, reduced slopes, and associated knickpoints. We find the position of these relief changes within the orogen is dependent on the position of the Pleistocene ELA. While alpine glaciers overdeepened valleys in regions near the Pleistocene ELA (which has a tendency to increase relief), headward erosion of west and north flowing glacier systems captured significant area from opposing systems and caused drainage divide lowering. This divide lowering reduced relief throughout the range. We demonstrate similar topographic effects recorded in the basin hypsometries of other Cenozoic mountain ranges around the world. The significant glacial overprint on

  6. Climate dominated topography in a tectonically active mountain range

    Science.gov (United States)

    Adams, B. A.; Ehlers, T. A.

    2015-12-01

    Tests of the interactions between tectonic and climate forcing on Earth's topography often focus on the concept of steady-state whereby processes of rock deformation and erosion are opposing and equal. However, when conditions change such as the climate or tectonic rock uplift, then surface processes act to restore the balance between rock deformation and erosion by adjusting topography. Most examples of canonical steady-state mountain ranges lie within the northern hemisphere, which underwent a radical change in the Quaternary due to the onset of widespread glaciation. The activity of glaciers changed erosion rates and topography in many of these mountain ranges, which likely violates steady-state assumptions. With new topographic analysis, and existing patterns of climate and rock uplift, we explore a mountain range previously considered to be in steady-state, the Olympic Mountains, USA. The broad spatial trend in channel steepness values suggests that the locus of high rock uplift rates is coincident with the rugged range core, in a similar position as high temperature and pressure lithologies, but not in the low lying foothills as has been previously suggested by low-temperature thermochronometry. The details of our analysis suggest the dominant topographic signal in the Olympic Mountains is a spatial, and likely temporal, variation in erosional efficiency dictated by orographic precipitation, and Pleistocene glacier ELA patterns. We demonstrate the same topographic effects are recorded in the basin hypsometries of other Cenozoic mountain ranges around the world. The significant glacial overprint on topography makes the argument of mountain range steadiness untenable in significantly glaciated settings. Furthermore, our results suggest that most glaciated Cenozoic ranges are likely still in a mode of readjustment as fluvial systems change topography and erosion rates to equilibrate with rock uplift rates.

  7. Active Tectonic Research for Seismic Safety Evaluation of Long-Line Engineering Sites in China

    Institute of Scientific and Technical Information of China (English)

    Ran Yongkang; Chen Lichun

    2005-01-01

    Long-line engineering sites usually have to pass through active tectonics, so the research of active tectonics is of great importance to seismic safety evaluation of this sort of site. In the paper, basing on the summarization and analysis of the requirements for seismic safety evaluation of long-line engineering site and the status quo of active tectonics research, we propose the focal points of active tectonics research for seismic safety evaluation of long-line engineering sites, including the research contents, technical targets and routes, and the submission of the achievements, etc. Finally, we make a preliminary analysis and discussion about the problems existing in the present-day active tectonics research for seismic safety evaluation of long-line engineering sites.

  8. New constraints on the active tectonic deformation of the Aegean

    Science.gov (United States)

    Nyst, M.; Thatcher, W.

    2004-01-01

    revealed by seismicity, active faulting, fault geomorphology, and earthquake fault plane solutions, continental tectonics, at least in the Aegean, is to first order very similar to global plate tectonics and obeys the same simple kinematic rules. Although the widespread distribution of Aegean seismicity and active faulting might suggest a rather spatially homogeneous seismic hazard, the focusing of deformation near microplate boundaries implies the highest hazard is comparably localized.

  9. Current Research Activities.

    Science.gov (United States)

    1975-02-01

    Biological oceanography, marine food chain dynamics, carbon cycling in the ocean. Martin, Seelye,Ph.D., Johns Hopkins. Geophysical fluid dynamics...currently under investigation, (Ahmed, Packard) 8. Amylase studies An assay for amylase activity has been adapted to measure zooplankton grazing. This...as a function of available food and of the biomass of copepods, was prescribed by sixteen equations: five, corresponding to copepodite stages (I to V

  10. Applications of Morphochronology to the Active Tectonics of Tibet

    Energy Technology Data Exchange (ETDEWEB)

    Ryerson, F J; Tapponnier, P; Finkel, R C; Meriaux, A; der Woerd, J V; Lasserre, C; Chevalier, M; Xiwei, X; Haibing, L; King, G P

    2005-01-28

    The Himalayas and the Tibetan Plateau were formed as a result of the collision of India and Asia, and provide an excellent opportunity to study the mechanical response of the continental lithosphere to tectonic stress. Geophysicists are divided in their views on the nature of this response advocating either (1) homogeneously distributed deformation with the lithosphere deforming as a fluid continuum or (2) deformation is highly localized with the lithosphere that deforms as a system of blocks. The resolution of this issue has broad implications for understanding the tectonic response of continental lithosphere in general. Homogeneous deformation is supported by relatively low decadal, geodetic slip-rate estimates for the Altyn Tagh and Karakorum Faults. Localized deformation is supported by high millennial, geomorphic slip-rates constrained by both cosmogenic and radiocarbon dating on these faults. Based upon the agreement of rates determined by radiocarbon and cosmogenic dating, the overall linearity of offset versus age correlations, and on the plateau-wide correlation of landscape evolution and climate history, the disparity between geomorphic and geodetic slip-rate determinations is unlikely to be due to the effects of surface erosion on the cosmogenic age determinations. Similarly, based upon the consistency of slip-rates over various observation intervals, secular variations in slip-rate appear to persist no longer than 2000 years and are unlikely to provide reconciliation. Conversely, geodetic and geomorphic slip-rate estimates on the Kunlun fault, which does not have significant splays or associated thrust faults, are in good agreement, indicating that there is no fundamental reason why these complementary geodetic and geomorphic methods should disagree. Similarly, the geodetic and geomorphic estimates of shortening rates across the northeastern edge of the plateau are in reasonable agreement, and the geomorphic rates on individual thrust faults demonstrate

  11. Active tectonics around the Mediterranean region: site studies and application of new methodologies

    Directory of Open Access Journals (Sweden)

    Luigi Cucci

    2013-01-01

    Full Text Available More than 25 years have passed since the definition of Active Tectonics as "tectonic movements that are expected to occur within a future time span of concern to society", formulated in a milestone book by the National Research Council on this topic (Studies in Geophysics, Active Tectonics, National Academy Press, Washington, D.C. 1986, and those words have still to be considered the most suitable and exhaustive way to explain this branch of the Earth Sciences. Indeed only bridging together basic studies ("tectonic movements", rates of occurrence ("time span" and hazard assessment ("society" can we fully evaluate ongoing tectonic activity and its associated hazards. The broad Mediterranean Sea region is a paradigmatic area from this point of view, as on one hand this region displays in a relatively limited geographic extent a great variety of tectonic processes such as plate collision, subduction, volcanic activity, large-magnitude earthquakes, active folding and faulting, vertical uplift and/or subsidence. On the other hand, all the above mentioned tectonic processes can potentially affect a total population of about 450 million, mostly concentrated in fast-growing urban areas and/or close to industrial compounds and critical facilities often located nearby hazard sources. […

  12. Geodynamic evolution of the Earth over the Phanerozoic:Plate tectonic activity and palaeoclimatic indicators

    Institute of Scientific and Technical Information of China (English)

    Christian Vérard; Cyril Hochard; Peter O. Baumgartner; Gérard M. Stamplfi

    2015-01-01

    During the last decades, numerous local reconstructions based on ifeld geol-ogy were developed at the University of Lausanne (UNIL). Team members of the UNIL partici-pated in the elaboration of a 600 Ma to present global plate tectonic model deeply rooted in geological data, controlled by geometric and kinematic constraints and coherent with forces acting at plate boundaries. In this paper, we compare values derived from the tectonic model (ages of oceanic lfoor, production and subduction rates, tectonic activity) with a combination of chemical proxies (namely CO2, 87Sr/86Sr, glaciation evidence, and sea-level variations) known to be strongly in-lfuenced by tectonics. One of the outstanding results is the observation of an overall decreas-ing trend in the evolution of the global tectonic activity, mean oceanic ages and plate velocities over the whole Phanerozoic. We speculate that the decreasing trend relfects the global cooling of the Earth system. Additionally, the parallel between the tectonic activity and CO2 together with the extension of glaciations conifrms the generally accepted idea of a primary control of CO2 on climate and highlights the link between plate tectonics and CO2 in a time scale greater than 107 yr. Last, the wide variations observed in the reconstructed sea-lfoor production rates are in contradiction with the steady-state model hypothesized by some.

  13. World Encircling Tectonic Vortex Street - Geostreams Revisited: The Southern Ring Current EM Plasma-Tectonic Coupling in the Western Pacific Rim

    Science.gov (United States)

    Leybourne, Bruce; Smoot, Christian; Longhinos, Biju

    2014-05-01

    Interplanetary Magnetic Field (IMF) coupling to south polar magnetic ring currents transfers induction energy to the Southern Geostream ringing Antarctica and underlying its encircling mid-ocean ridge structure. Magnetic reconnection between the southward interplanetary magnetic field and the magnetic field of the earth is the primary energy transfer mechanism between the solar wind and the magnetosphere. Induced telluric currents focused within joule spikes along Geostreams heat the southern Pacific. Alignment of the Australian Antarctic Discordance to other tectonic vortexes along the Western Pacific Rim, provide electrical connections to Earths core that modulate global telluric currents. The Banda Sea Triple Junction, a mantle vortex north of Australia, and the Lake Baikal Continental Rift vortex in the northern hemisphere modulate atmospheric Jetstream patterns gravitationally linked to internal density oscillations induced by these telluric currents. These telluric currents are driven by solar magnetic power, rotation and orbital dynamics. A solar rotation 40 day power spectrum in polarity controls north-south migration of earthquakes along the Western Pacific Rim and manifest as the Madden Julian Oscillation a well-documented climate cycle. Solar plasma turbulence cycles related to Hale flares trigger El Nino Southern Oscillations (ENSO's), while solar magnetic field strength frequencies dominate global warming and cooling trends indexed to the Pacific Decadal Oscillation. These Pacific climate anomalies are solar-electro-tectonically modulated via coupling to tropical geostream vortex streets. Particularly the section along the Central Pacific Megatrend connecting the Banda Sea Triple Junction (up welling mantle vortex) north of Australia with the Easter Island & Juan Fernandez twin rotating micro-plates (twin down welling mantle vortexes) along the East Pacific Rise modulating ENSO. Solar eruptions also enhance the equatorial ring current located

  14. Geodynamic evolution of the Earth over the Phanerozoic: Plate tectonic activity and palaeoclimatic indicators

    Directory of Open Access Journals (Sweden)

    Christian Vérard

    2015-04-01

    In this paper, we compare values derived from the tectonic model (ages of oceanic floor, production and subduction rates, tectonic activity with a combination of chemical proxies (namely CO2, 87Sr/86Sr, glaciation evidence, and sea-level variations known to be strongly influenced by tectonics. One of the outstanding results is the observation of an overall decreasing trend in the evolution of the global tectonic activity, mean oceanic ages and plate velocities over the whole Phanerozoic. We speculate that the decreasing trend reflects the global cooling of the Earth system. Additionally, the parallel between the tectonic activity and CO2 together with the extension of glaciations confirms the generally accepted idea of a primary control of CO2 on climate and highlights the link between plate tectonics and CO2 in a time scale greater than 107 yr. Last, the wide variations observed in the reconstructed sea-floor production rates are in contradiction with the steady-state model hypothesized by some.

  15. Appraisal of active tectonics in Hindu Kush: Insights from DEM derived geomorphic indices and drainage analysis

    Directory of Open Access Journals (Sweden)

    Syed Amer Mahmood

    2012-07-01

    The results obtained from these indices were combined to yield an index of relative active tectonics (IRAT using GIS. The average of the seven measured geomorphic indices was used to evaluate the distribution of relative tectonic activity in the study area. We defined four classes to define the degree of relative tectonic activity: class 1__very high (1.0 ≤ IRAT < 1.3; class 2__high (1.3 ≥ IRAT < 1.5; class 3—moderate (1.5 ≥ IRAT < 1.8; and class 4—low (1.8 ≥ IRAT. In view of the results, we conclude that this combined approach allows the identification of the highly deformed areas related to active tectonics. Landsat imagery and field observations also evidence the presence of active tectonics based on the deflected streams, deformed landforms, active mountain fronts and triangular facets. The indicative values of IRAT are consistent with the areas of known relative uplift rates, landforms and geology.

  16. An Introduction to the Latest-generation Spatial Database of Active Tectonics of China

    Institute of Scientific and Technical Information of China (English)

    Qu Chunyan; Deng Qidong

    2009-01-01

    Based on ArcGIS and MapInfo software, we digitized the active tectonics map (1:4,000,000) of China, which was compiled and revised by academician Deng Qidong, and built the spatial database of active tectonics of China. The database integrates rich active tectonic data, such as a catalogue of earthquakes with magnitude above 6.0, active faults, Quaternary basins, active folds and their associated attribute parameters, and implements scientific and effective management to this data. At the same time, the spatial database joins the spatial map data and the associated attribute data together, which implements the data query between spatial properties and attribute parameters and also makes it possible to perform spatial analysis with different data layers. These provide much convenience for earthquake study and allows engineering construction institutions to use this data in practical applications.

  17. Spatial-temporal variation of the land surface temperature field and present-day tectonic activity

    Directory of Open Access Journals (Sweden)

    Jin Ma

    2010-10-01

    Full Text Available This study attempts to acquire information on tectonic activity in western China from land surface temperature (LST field data. On the basis of the established relationship between heat and strain, we analyzed the LST distribution in western China using the satellite data product MODIS/Terra. Our results show that: 1. There are departures from annual changes of LST in some areas, and that these changes are associated with the activity of some active tectonic zones. 2. When annual-change background values caused by climate factors are removed, the long-period component (LSTLOW of temperature residual (ΔT of the LST is able to serve as an indicator for tectonic activity. We have found that a major earthquake can produce different effects on the LST fields of surrounding areas. These effects are characterized by both rises and drops in temperature. For example, there was a noteworthy temperature decline associated with the Sumatran M9 earthquake of 2004 in the Bayan Har-Songpan block of central Tibetan Plateau. 3. On the other hand, the LST field of a single area may respond differently to major shocks occurring in different areas in the regions surrounding China. For instance, the Kunlun M 8.1 event made the LST on the Longmen Mountains fault zone increase, whereas the Zaisan Lake M 7.9 quake of 2003, and the Sumatran M 9 event of 2004, caused decreases in the same area’s LST. 4. The variations of land surface temperature (LST over time are different in different tectonic areas. These phenomena may provide clues for the study of tectonic deformation processes. On the basis of these phenomena, we use a combination of temperature data obtained at varied depths, regional seismicity and strain results obtained with GPS measurements, to test the information related to tectonic activity derived from variations of the LST field, and discuss its implications to the creation of models of regional tectonic deformation.

  18. Sea Level Changes and Active Tectonics of the Guerrero Coast, Mexico

    Science.gov (United States)

    Ramirez-Herrera, M.; Cundy, A. B.; Sedor, M.; Kostoglodov, V.

    2003-12-01

    Understanding the interaction between sea-level changes and tectonic activity during the Holocene is essential in determining long-term tectonic deformation rates and in identifying prehistorical earthquake events along active margins. The Guerrero coast extends along the active Pacific margin of southwest Mexico and parallels the trench where the Cocos Plate subducts beneath the North American Plate. The last major earthquakes occurred in Guerrero in 1899, 1907, 1909, 1911, and 1957, but none have occurred since the major 1911 (Ms=7.6) earthquake in the northwest segment of the Guerrero seismic gap. The Guerrero gap is currently considered to be matured for a severe earthquake of estimated Mw= 8.1 to 8.4. We present preliminary results of geomorphic field surveying, sediment coring, and geochemical and microfaunal analyses of cored sediments on the Guerrero coast. The Coyuca lagoon strip of the Guerrero coast consists of long barrier beaches, behind which extends a lagoon, beach ridges, extensive swamps, mangrove swamps, salt pans, floodplains, alluvial plains, fluvial terraces, and abandoned meanders. Abandoned meanders and fluvial terraces indicate that the Coyuca River has migrated to the southeast. This migration, and changes in hill elevations near the coast, suggest a southeast tilting of this coastal segment. The morphology of the Guerrero coast has no evidence of long-term coastal uplift. This is consistent with short- term tide gauge measurements (1953-1999) and GPS data (1992-2000) indicative of subsidence rates of ~3 mm/yr (Kostoglodov et al., 2001) in this area. Five cores up to 5.5 m depth were taken nearby the Mitla, Coyuca, Tres Palos and Tecomate lagoons. Core stratigraphies show clear sequences of interbedded peats and clays, interspersed with sand units. The peat-clay sequences are similar to those observed along active margins elsewhere, and indicate fluctuations between marine and brackish/freshwater conditions. Two cores included sediments

  19. Recent Tectonic Activity on Pluto Driven by Phase Changes in the Ice Shell

    CERN Document Server

    Hammond, Noah P; Parmentier, Edgar M

    2016-01-01

    The New Horizons spacecraft has found evidence for geologic activity on the surface of Pluto, including extensional tectonic deformation of its water ice bedrock (see Moore et al., 2016). One mechanism that could drive extensional tectonic activity is global surface expansion due to the partial freezing of an ocean. We use updated physical properties for Pluto and simulate its thermal evolution to understand the survival of a possible subsurface ocean. For thermal conductivities of rock less than 3 W m$^{-1}$ K$^{-1}$, an ocean forms and at least partially freezes, leading to recent extensional stresses in the ice shell. In scenarios where the ocean freezes and the ice shell is thicker than $260$ km, ice II forms and causes global volume contraction. Since there is no evidence for recent compressional tectonic features, we argue that ice II has not formed and that Pluto's ocean has likely survived to present day.

  20. Research on the Characteristics of Large Earthquake Activity on the Active Tectonic Boundaries on the Chinese Mainland

    Institute of Scientific and Technical Information of China (English)

    Ma Hongsheng; Zhang Guomin; Liu Jie; Wang Hui

    2006-01-01

    Based on the research and the division of the active tectonic blocks and their boundaries on the Chinese mainland, the feature of the large earthquake activities on the 24 boundaries between the 6 active tectonic block regions (grade Ⅰ ) and the 22 active tectonic blocks (grade Ⅱ ) are studied. The seismicity levels on the active tectonic block boundaries are discussed considering the large earthquake frequency and the released strain energy in unit distance and time. The theoretic maximal magnitude and the recurrence period of each boundary are then calculated from the G-R relation. By comparing this with the actual earthquake records, it is found that the intensities of the earthquake deduced from the seismic activity parameter (a/b) on the main active boundaries on the Chinese mainland are consistent with that of the natural earthquakes. Meanwhile, an inverse relation is found between the recurrence periods of large earthquakes and the tectonic motion rate on the boundaries. These results show that the a, b values of each boundary obtained in this paper are valuable. In addition, the present seismic activities and hazards of these boundaries are also probed into with the historical data and their elapsed time on each boundary based on the hypothesis that the large earthquakes satisfy Poisson distribution.

  1. Morphometric analysis of relative tectonic activity in the Baturagung Mountain, Central Java, Indonesia

    Science.gov (United States)

    Mulyasari, Rahmi; Brahmantyo, Budi; Supartoyo

    2017-06-01

    Special Region of Yogyakarta and Klaten district, Central Java is one of areas in Indonesia that is prone to earthquake caused by subduction in Indian Ocean and active fault in land. The earthquake sources from active fault probable from Opak and other faults located in Baturagung Mountain. Active faults controlling landform development in tectonically active regions, and it has significantly affected fluvial systems and mountain - front landscapes in the Baturagung Mountain. To assess tectonic activities in the area used quantitative analysis (morphometric). Morphometric analysis consists of 5 parameters geomorphic indices: drainage basin asymmetry (AF), hypsometric curve and integral (Hc and Hi), stream length gradient (SL) index, basin shape index (Bs), and mountain-front sinuosity (Smf). These indices were combined to yield the relative tectonic activity index (RTAI) using geographic information systems (GIS). The result found that RTAI in the study area are divided into three classes: Class 2 (high 0.6% of the watershed area (1.32 km2)); Class 3 (moderate 58.9% (122.1 km2)); and Class 4 (low 40.4% (83.75 km2)). All of morphometric analysis generally indicates this area more influenced by tectonics than erosion. The results are consistent with geomorphological observations.

  2. Preliminary study on hydrogeology in tectonically active areas.

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, Thomas Stephen; Lappin, Allen R.; Gettemy, Glen L.; Jensen, Richard Pearson; Arnold, Bill Walter; James, Scott Carlton; Lee, Moo Yul; Meier, Diane A.

    2006-09-01

    This report represents the final product of a background literature review conducted for the Nuclear Waste Management Organization of Japan (NUMO) by Sandia National Laboratories, Albuquerque, New Mexico, USA. Internationally, research of hydrological and transport processes in the context of high level waste (HLW) repository performance, has been extensive. However, most of these studies have been conducted for sites that are within tectonically stable regions. Therefore, in support of NUMO's goal of selecting a site for a HLW repository, this literature review has been conducted to assess the applicability of the output from some of these studies to the geological environment in Japan. Specifically, this review consists of two main tasks. The first was to review the major documents of the main HLW repository programs around the world to identify the most important hydrologic and transport parameters and processes relevant in each of these programs. The review was to assess the relative importance of processes and measured parameters to site characterization by interpretation of existing sensitivity analyses and expert judgment in these documents. The second task was to convene a workshop to discuss the findings of Task 1 and to prioritize hydrologic and transport parameters in the context of the geology of Japan. This report details the results and conclusions of both of these Tasks.

  3. Drainage - Structure Correlation in tectonically active Regions: Case studies in the Bolivian and Colombian Andes

    Science.gov (United States)

    Zeilinger, Gerold; Parra, Mauricio; Kober, Florian

    2017-04-01

    It is widely accepted, that drainage patterns are often controlled by tectonics/climate and geology/rheology. Classical drainage patterns can be found 1) in fault-and-thrust belt, where rives follow the valleys parallel or cut perpendicular to strike trough the ridges, forming a trellis pattern, 2) at dome structures where the drainage form a radial pattern or 3) rectangular patterns in strongly fractured regions. In this study, we focus on fault-and-thrust belts, that undergone different phases of tectonic activity. According to classical models, the deformation is propagating into the foreland, hence being youngest at the frontal part and getting successively older towards the axis of the orogen. Drainage patterns in the more interior parts of the orogenic wedge should be then less influenced by the direction of structures, as landscape evolution is changing to a tectonic passive stage. This relationship might represent the transience and maturity of drainage pattern evolution. Here we study drainage patterns of the Bolivian and the eastern Colombian Andes by comparing the relative orientation of the drainage network with the orogen structural grain. The drainage is extracted from Digital Elevation Models (SRTM 30 m) and indexed by their Strahler Order. Order 1 channels have an upstream area of 1 km2. The direction of all segments is analyzed by linear directional mean function that results in the mean orientation of input channels with approx. 500 m average length. The orientation of structures for different structural domains is calculated using the same function on digitized faults and fold-axis. Rose diagrams show the length-weighted directional distribution of structures, of higher (>= 4) and of lower order (tectonic activity. The only weakly preferred orientation of drainages in the interior parts (EC and IR) suggests a balance between structural control and drainage occupation, and higher maturity of the landscape. In contrast, the distinct pattern of

  4. The River Network, Active Tectonics and the Mexican Subduction Zone, Southwest Mexico

    Science.gov (United States)

    Gaidzik, K.; Ramirez-Herrera, M. T.; Kostoglodov, V.; Basili, R.

    2014-12-01

    Rivers, their profiles and network reflect the integration of multiple processes and forces that are part of the fundamental controls on the relief structure of mountain belts. The motivation of this study is to understand active tectonic processes in the forearc region of subduction zones, by distinguishing evidence of active deformation using the river network and topography. To this end, morphotectonic and structural studies have been conducted on fifteen drainage basins on the mountain front, parallel to the Mexican subduction zone, where the Cocos plate underthrusts the North American plate. The southwest - northeast Cocos plate subduction stress regime initiated ca. 20 MA. NE-SW to NNE-SSW normal faults as well as sub-latitudinal to NW-SE strike-slip faults (both dextral and sinistral) constitute the majority of mesofaults recorded in the field within the studied drainage basins. Occasionally dextral N-S strike-slip faults also occur. The stress tensor reconstruction suggests two main evolution stages of these faults: 1) the older is dominated by a NW-SE to WNW-ESE extensional regime and 2) the younger is a transcurrent regime, with NNE-SSW σ1 axis. The drainage pattern is strongly controlled by tectonic features, whereas lithology is only a subordinate factor, with only one exception (Petatlán river). Generally, major rivers flow from north to south mainly through NE-SW and NNE-SSW normal faults, and/or sub-longitudinal dextral (also locally sinistral) strike-slip faults. In the central and eastern part of the studied area, rivers also follow NW-SE structures, which are generally normal or sinistral strike-slip faults (rarely reverse). In most cases, local deflections of the river main courses are related to sub-latitudinal strike-slip faults, both dextral and sinistral. Within the current stress field related to the active Cocos subduction, both normal and strike-slip fault sets could be reactivated. Our analysis suggests that strike-slip faults, mainly

  5. Assessment of relative tectonic activity in the Trichonis Lake graben (Western Greece) using geomorphometry

    Science.gov (United States)

    Karymbalis, Efthimios; Valkanou, Kanella; Fubelli, Giandomenico; Ferentinou, Maria; Giles, Philip; Papanastassiou, Dimitris; Gaki-Papanastassiou, Kalliopi; Tsanakas, Konstantinos

    2016-04-01

    In tectonically active areas fluvial systems and mountain fronts are controlled by the type, geometry, and recent activity of faults. The aim of this study is to investigate the contribution of neotectonics to the development of the fluvial landscape of the broader Trichonis Lake area (located in western continental Greece) through quantitative geomorphological analysis. The Trichonis Lake graben is a well-known tectonic depression of Quaternary age, which cuts across the early Tertiary NW-SE fold and thrust structures of the Pindos Mountain belt. It strikes WNW-ESE for a distance of 32 km and has a width of 10 km. The graben at the north and south flanks of the lake is bounded by E-W and NW-SE trending faults. Recent seismic activity (a shallow earthquake sequence in 1975 and a 2007 earthquake swarm) showed the existence of a NNW-SSE normal fault that dips to the NE and bounds the south-eastern shore of the lake. The studied catchments are developed on the hanging walls of these active normal faults. To evaluate the relative tectonic activity in the study area, various morphometric indices were measured for 35 catchments (slope of the valley sides of the catchment, hypsometric integral, catchment asymmetry factor, relief ratio, Melton's ruggedness number, stream-gradient index, ratio of valley floor width to valley height, and catchment shape) and 20 mountain fronts (mountain-front sinuosity index) around the lake. For the measurement of the geomorphometric variables a digital elevation model (DEM) with 2-m spatial resolution was derived from topographic maps at 1:5000 scale with 4-m contour lines, and a series of maps showing the spatial distribution of the variables were produced in a GIS environment. For each morphometric variable the catchments were classified into three classes. The combination of these morphometric variables allowed us to yield two new indices of relative tectonic activity (named IRTA - Index of Relative Tectonic Activity and IAT - Index of

  6. Tectonic activity and the evolution of submarine canyons: The Cook Strait Canyon system, New Zealand

    Science.gov (United States)

    Micallef, Aaron; Mountjoy, Joshu; Barnes, Philip; Canals, Miquel; Lastras, Galderic

    2016-04-01

    Submarine canyons are Earth's most dramatic erosional features, comprising steep-walled valleys that originate in the continental shelf and slope. They play a key role in the evolution of continental margins by transferring sediments into deep water settings and are considered important biodiversity hotspots, pathways for nutrients and pollutants, and analogues of hydrocarbon reservoirs. Although comprising only one third of continental margins worldwide, active margins host more than half of global submarine canyons. We still lack of thorough understanding of the coupling between active tectonics and submarine canyon processes, which is necessary to improve the modelling of canyon evolution in active margins and derive tectonic information from canyon morphology. The objectives of this study are to: (i) understand how tectonic activity influences submarine canyon morphology, processes, and evolution in an active margin, and (2) formulate a generalised model of canyon development in response to tectonic forcing based on morphometric parameters. We fulfil these objectives by analysing high resolution geophysical data and imagery from Cook Strait Canyon system, offshore New Zealand. Using these data, we demonstrate that tectonic activity, in the form of major faults and structurally-generated tectonic ridges, leaves a clear topographic signature on submarine canyon location and morphology, in particular their dendritic and sinuous planform shapes, steep and linear longitudinal profiles, and cross-sectional asymmetry and width. We also report breaks/changes in canyon longitudinal slope gradient, relief and slope-area regression models at the intersection with faults. Tectonic activity gives rise to two types of knickpoints in the Cook Strait Canyon. The first type consists of low slope gradient, rounded and diffusive knickpoints forming as a result of short wavelength folds or fault break outs and being restored to an equilibrium profile by upstream erosion and

  7. Active inversion tectonics, simple shear folding and back-thrusting at Rioni Basin, Georgia

    Science.gov (United States)

    Tibaldi, A.; Alania, V.; Bonali, F. L.; Enukidze, O.; Tsereteli, N.; Kvavadze, N.; Varazanashvili, O.

    2017-03-01

    The Rioni Basin, located between the Greater and Lesser Caucasus in Georgia, is an outstanding example of ongoing inversion tectonics. Marine and continental deposits of Cretaceous-Neogene age have been locally uplifted since the end of Miocene. The uplifted area totals 1300 km2, and Plio-Quaternary river deposits have been raised up to 200 m above the surrounding plains. Inversion tectonics has been accompanied by the development of south-vergent asymmetrical folds and strike-slip faults along the border of the uplifted area. The folds have locally an en-échelon geometry and microtectonic data indicate rotation of the paleostress direction over time, suggesting simple shear deformation. In the interiors of the uplifted area, there are gentle symmetrical folds and one main active south-dipping reverse fault, corresponding to a backthrust. Morphostructural evidence, as well as the tilting of Quaternary strata, the offset of Quaternary alluvial deposits and the presence of crustal seismic activity, indicate that compressional tectonics is still active. The combination of field data with seismic reflection sections shows that inversion tectonics took place through a series of north-dipping blind thrusts and a wedge with passive back-thrusting. Uplift and contraction are more developed along the eastern part of the study area, suggesting the westward propagation of the closure of the Transcaucasian depression.

  8. Evaluating influence of active tectonics on spatial distribution pattern of floods along eastern Tamil Nadu, India

    Science.gov (United States)

    Selvakumar, R.; Ramasamy, SM.

    2014-12-01

    Flooding is a naturally recurrent phenomenon that causes severe damage to lives and property. Predictions on flood-prone zones are made based on intensity-duration of rainfall, carrying capacity of drainage, and natural or man-made obstructions. Particularly, the lower part of the drainage system and its adjacent geomorphic landforms like floodplains and deltaic plains are considered for analysis, but stagnation in parts of basins that are far away from major riverine systems is less unveiled. Similarly, uncharacteristic flooding in the upper and middle parts of drainage, especially in zones of an anomalous drainage pattern, is also least understood. Even though topographic differences are attributed for such anomalous spatial occurrence of floods, its genetic cause has to be identified for effective management practice. Added to structural and lithological variations, tectonic movements too impart micro-scale terrain undulations. Because active tectonic movements are slow-occurring, long-term geological processes, its resultant topographical variations and drainage anomalies are least correlated with floods. The recent floods of Tamil Nadu also exhibit a unique distribution pattern emphasizing the role of tectonics over it. Hence a detailed geoinformatics-based analysis was carried out to envisage the relationship between spatial distribution of flood and active tectonic elements such as regional arches and deeps, block faults, and graben and drainage anomalies such as deflected drainage, compressed meander, and eyed drainages. The analysis reveals that micro-scale topographic highs and lows imparted by active tectonic movements and its further induced drainage anomalies have substantially controlled the distribution pattern of flood.

  9. Geomorphic assessment of the tectonic activity of Qiulitagh fold-belt, Kuqa foreland basin, Xinjiang, China

    Science.gov (United States)

    Saint Carlier, Dimitri; Graveleau, Fabien; Delcaillau, Bernard; Hurtrez, Jean-Emmanuel; Vendeville, Bruno

    2014-05-01

    The Qiulitagh fold belt is an anticline structure located in the Kuqa fold-and-thrust belt (southern Tian Shan, China), whose active folding is well documented by structural and palaeomagnetic studies (Chen et al., 2007; Hubert-Ferrari et al., 2007; Li et al., 2012; Wang et al., 2011). The topography of Quilitagh fold belt can be divided into two SW-NE parallel ridges: 1) a 90 km long northern ridge, composed of the Northern Qiulitagh anticline and the Yakelike anticline, and 2) a 165km long southern ridge, composed of the Southern Qiulitagh anticline and the Mishikantage anticline. Due to the current absence of vegetation and relative homogeneity of outcropping lithologies (mainly Neogene detrital sandstone and silstone), these anticlines provide exceptional field cases for investigating the dynamic relationships between fold growth mechanisms, the subsurface structures, the geomorphic entities and the drainage network evolution. We used free topographic and satellite image datasets to carry out a morphometric study of the Quilitagh fold-belt and investigate the kinematics of active folding. Topographic datasets include Digital Elevation Models (DEM) from the NASA SRTM V.4.0 and ASTER programs, whereas satellite images are extracted from Landsat 7 shots and Google Earth. These datasets were incorporated in GIS software where three scales of observation were investigated: 1) a global fold scale, 2) a drainage basin scale and 3) a valley scale. At the drainage basin scale, we selected about 250 items and quantified several geomorphic indices of relative active tectonic growth. These are the basin mean slope, hypsometric integral, basin asymmetry and local relief. We also used published seismic profiles to link the 3D subsurface geometry of the salt-related Qiulitagh fold belt with the geomorphic signal. Results indicate that the morphometry of Quilitagh drainage basins (hypsometry, drainage basin asymmetry, local relief, valley incision, steepness index) change

  10. Active tectonics of the Oran (Algeria) Quaternary plain

    Science.gov (United States)

    youcef, Bouhadad; rabah, Bensalem; e-hadi, oubaiche

    2016-04-01

    The Oran region, in north-western Algeria, has been hit several times in the past by destructive moderate-sized and strong earthquakes. The Oran October 9th , 1790 (I0= X) was among the strongest seismic events in the western Mediterranean area comparable, if we consider the described effects, to the El- Asnam (1980, Ms=7.3) and Zemmouri (2003, Mw=6.8) earthquakes. Such strong seismic events requires the presence of major active geological structures that are re-activated several times in the past. In this work we present results of a multi- disciplinary study combining geomorphic analysis, field earthquake geological investigations and geophysical methods, undertaken to study the southern border of the Oran Quaternary plain. A 50 km long, SW-dipping and NE-SW trending active fault has been identified that showing clear quaternary deformation. Keywords: earthquake geology, active fault, geomorphic, geophysics, Algeria.

  11. Linking Europa's plume activity to tides, tectonics, and liquid water

    CERN Document Server

    Rhoden, Alyssa R; Roth, Lorenz; Retherford, Kurt

    2015-01-01

    Much of the geologic activity preserved on Europa's icy surface has been attributed to tidal deformation, mainly due to Europa's eccentric orbit. Although the surface is geologically young (30 - 80 Myr), there is little information as to whether tidally-driven surface processes are ongoing. However, a recent detection of water vapor near Europa's south pole suggests that it may be geologically active. Initial observations indicated that Europa's plume eruptions are time-variable and may be linked to its tidal cycle. Saturn's moon, Enceladus, which shares many similar traits with Europa, displays tidally-modulated plume eruptions, which bolstered this interpretation. However, additional observations of Europa at the same time in its orbit failed to yield a plume detection, casting doubt on the tidal control hypothesis. The purpose of this study is to analyze the timing of plume eruptions within the context of Europa's tidal cycle to determine whether such a link exists and examine the inferred similarities and...

  12. Digital Tectonic Tools

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due

    2005-01-01

    in particular. A model of the aspects in the term tectonics – epresentation, ontology and culture – will be presented and used to discuss the current digital tools’ ability in tectonics. Furthermore it will be discussed what a digital tectonic tool is and could be and how a connection between the digital...

  13. Textile Tectonics

    DEFF Research Database (Denmark)

    Mossé, Aurélie

    2008-01-01

    The meeting of architecture and textiles is a continuous but too often forgotten story of intimate exchange. However, the 2nd Ventulett Symposium hosted by the College of Architecture, within Georgia Institute of Technology, Atlanta, GA, was one of these precious moments celebrating such a marriage....... Organized by Lars Spuybroeck, principal of Nox, Rotterdam, and current Thomas W. Ventulett III distinguished chair of Architectural Design, the event was embracing the textile tectonics as a core topic, praising textiles as the key component of architecture, relying on Gottfried Semper’s understanding...... of the discipline. Inspiring time gathering some of the most exciting architects of the moment, Lars Spuybroeck, Mark Burry, Evan Douglis, Michael Hensel and Cecil Balmond were invited to discuss their understanding of tectonics. Full text available at http://textilefutures.co.uk/exchange/bin/view/TextileFutures/TextileTectonics...

  14. Inferring tectonic activity using drainage network and RT model: an example from the western Himalayas, India

    Science.gov (United States)

    Sahoo, Ramendra; Jain, Vikrant

    2017-04-01

    Morphology of the landscape and derived features are regarded to be an important tool for inferring about tectonic activity in an area, since surface exposures of these subsurface processes may not be available or may get eroded away over time. This has led to an extensive research in application of the non-planar morphological attributes like river long profile and hypsometry for tectonic studies, whereas drainage network as a proxy for tectonic activity has not been explored greatly. Though, significant work has been done on drainage network pattern which started in a qualitative manner and over the years, has evolved to incorporate more quantitative aspects, like studying the evolution of a network under the influence of external and internal controls. Random Topology (RT) model is one of these concepts, which elucidates the connection between evolution of a drainage network pattern and the entropy of the drainage system and it states that in absence of any geological controls, a natural population of channel networks will be topologically random. We have used the entropy maximization principle to provide a theoretical structure for the RT model. Furthermore, analysis was carried out on the drainage network structures around Jwalamukhi thrust in the Kangra reentrant in western Himalayas, India, to investigate the tectonic activity in the region. Around one thousand networks were extracted from the foot-wall (fw) and hanging-wall (hw) region of the thrust sheet and later categorized based on their magnitudes. We have adopted the goodness of fit test for comparing the network patterns in fw and hw drainage with those derived using the RT model. The null hypothesis for the test was, the drainage networks in the fw are statistically more similar than those on the hw, to the network patterns derived using the RT model for any given magnitude. The test results are favorable to our null hypothesis for networks with smaller magnitudes (< 9), whereas for larger

  15. Neutron flux variations near the Earth’s crust. A possible tectonic activity detection

    Directory of Open Access Journals (Sweden)

    B. M. Kuzhevskij

    2003-01-01

    Full Text Available The present work contains some results of observations of neutron flux variations near the Earth’s surface. The Earth’s crust is determined to be a significant source of thermal and slow neutrons, originated from the interaction between the nuclei of the elements of the Earth’s crust and the atmosphere and α-particles, produced by decay of radioactive gases (Radon, Thoron and Actinon. In turn, variations of radioactive gases exhalation is connected with geodynamical processes in the Earth’s crust, including tectonic activity. This determined relation between the processes in the Earth’s crust and neutrons’ flux allow to use variations of thermal and slow neutrons’ flux in order to observe increasing tectonic activity and to develop methods for short-term prediction of natural hazards.

  16. Active tectonics in the Argentine Precordillera and Western Sierras Pampeanas

    Directory of Open Access Journals (Sweden)

    L.L. Siame

    2006-12-01

    Full Text Available The Andean foreland of western Argentina (28°S-33°S corresponds to retroarc deformations associated with the ongoing flat subduction of the Nazca plate beneath the South American lithosphere. This region is characterized by high levels of seismic activity and crustal active faulting. To improve earthquake source identification and characterization in the San Juan region, data from seismology, structural geology and quantitative geomorphology were integrated and combined to provide a seismotectonic model. In this seismotectonic model, the Andean back-arc of western Argentina can be regarded as an obliquely converging foreland where Plio-Quaternary deformations are partitioned between strike-slip and thrust motions that are localized on the E-verging, thin-skinned Argentine Precordillera, and the W-verging thick-skinned Sierras Pampeanas, respectively. In this seismotectonic model, the Sierra Pie de Palo appears to be a key structure playing a major role in the partitioning of the Plio-Quaternary deformations.

  17. Tectonic Activity on Pluto After the Charon-Forming Impact

    CERN Document Server

    Barr, Amy C

    2014-01-01

    The Pluto-Charon system, likely formed from an impact, has reached the endpoint of its tidal evolution. During its evolution into the dual-synchronous state, the equilibrium tidal figures of Pluto and Charon would have also evolved as angular momentum was transferred from Pluto's spin to Charon's orbit. The rate of tidal evolution is controlled by Pluto's interior physical and thermal state. We examine three interior models for Pluto: an undifferentiated rock/ice mixture, differentiated with ice above rock, and differentiated with an ocean. For the undifferentiated case without an ocean, the Pluto-Charon binary does not evolve to its current state unless its internal temperature $T_i>200$ K, which would likely lead to strong tidal heating, melting, and differentiation. Without an ocean, Pluto's interior temperature must be higher than 240 K for Charon to evolve on a time scale less than the age of the solar system. Further tidal heating would likely create an ocean. If New Horizons finds evidence of ancient t...

  18. Active faulting and transpression tectonics along the plate boundary in North Africa

    OpenAIRE

    Mustapha Meghraoui; Silvia Pondrelli

    2012-01-01

    International audience; We present a synthesis of the active tectonics of the northern Atlas Mountains , and suggest a kinematic model of transpression and block rotation that illustrates the mechanics of this section of the Africa–Eurasia plate boundary. Neotectonic structures and significant shallow seismicity (with Mw >5.0) indicate that coeval E-W-trending, right-lateral faulting and NE-SW, thrust-related folding result from oblique convergence at the plate boundary, which forms a transpr...

  19. Integrated morphometric analysis in GIS environment applied to active tectonic areas.

    OpenAIRE

    Nappi, Rosa; Alessio, Giuliana

    2012-01-01

    This chapter describes a methodology for identifying the structural lineaments in active tectonic areas by integrating morphological and morphometrical data derived by DEMs (Digital Elevation Models) processing, with local seismicity data. Moreover, validation of the lineaments extracted from DEM has been carried out by examining literature geological and geomorphological data, aerial photo interpretation and field surveys. The morphometric parameters as the terrain slope, terrain aspect, ...

  20. Drainage Characteristics of Tectonically Active Areas: An Example from Rajasthan, India

    Directory of Open Access Journals (Sweden)

    SWATI JAIN

    2010-06-01

    Full Text Available The morphotectonic studies help in deciphering the role of tectonics and neotectonics in morphological evolution of drainage basins. On the basis of remote sensing technique, the relationship between morphology and tectonics have been investigated in Bundi-Indergarh sector of southeast Rajasthan. The area selected for present study is drained by Mej river and its tributaries and occupies the southeastern part of the Aravalli Mountain Range (AMR. The course of Mej river is mostly controlled by the Great Boundary Thrust (GBT and associated tectonic elements. GBT separates the folded, faulted and metamorphosed older rocks of the AMR in the west and relatively undeformed Vindhyan rocks in the east. This study has been carried out using digital and hard copy product of IRS 1C/1D LISS III geocoded FCC data. The morphometric and morphotectonic aspects have been studied for identification of present day tectonic activities in the area. The remote sensing data interpretation indicates that the landforms of the area are structurally controlled and mainly covered by linear and parallel strike ridges and valleys. These valleys indicate sign of stream rejuvenation and occasional presence of dynamic ravines. General morphometric parameters, bifurcation ratio, stream length and shape parameters have been computed. Longitudinal river profiles can be quantified by normalizing the elevation and the distance along rivers. Several parameters such as profile shape (concavity, gradient fluctuations, river grade and valley incision have been derived from longitudinal river profile. These quantified parameters and their interrelations are useful in comparing different drainage basins and also help drawing inferences on neotectonism. The computed values suggest that the area is covered by resistant rock and drainage network, affected by tectonic distur-bance. The valley floor ratio is very low, indicating channel down cutting vis-a-vis ground uplift. The gradient index

  1. Study provides data on active plate tectonics in southeast Asia region

    Science.gov (United States)

    Wilson, P.; Rais, J.; Reigber, Ch.; Reinhart, E.; Ambrosius, B. A. C.; Le Pichon, X.; Kasser, M.; Suharto, P.; Majid, Dato'Abdul; Yaakub, Dato'Paduka Awang Haji Othman Bin Haji; Almeda, R.; Boonphakdee, C.

    A major geodynamic study has provided significant new information about the location of active plate boundaries in and around Southeast Asia, as well as deformation processes in the Sulawesi region of Indonesia and tectonic activity in the Philippine archipelago. Results also have confirmed the existence of the so-called Sunda Block, which appears to be rotating with respect to adjacent plates.The study, known as the Geodynamics of South and South-East Asia (GEODYSSEA) project, has been a joint venture of the European Commission and the Association of South- East Asian Nations. It began in 1991 and involved a large team of European and Asian scientists and technicians studying the complex geodynamic processes and natural hazards of the region from the Southeast Asia mainland to the Philippines to northern Australia. Earthquakes, volcanic eruptions, tsunamis, and tectonically induced landslides endanger the lives of millions of people in the region, and the tectonic activity behind these natural hazards results from the convergence and collision of the Eurasian, Philippine, and Indo-Australian Plates at relative velocities of up to 10 cm per year.

  2. Recent earthquake activity in Trichonis region and its tectonic significance

    Directory of Open Access Journals (Sweden)

    N. DELIBASIS

    1977-06-01

    Full Text Available SUMMARY. - The aftershock activity associated with the central Greece
    (Trichonis Lake earthquake of |une-Dec. 1975, has been studied, with emphasis
    on the time and magnitude distribution. It has been found that the value of b,
    in Gutenberg - R i c h t e r ' s relationship was near the same for the primary as
    well as the secondary or second order aftershocks of the sequences, but depends
    upon the focal depth.
    A correlation between the calculated focal mechanisms and the associated
    stress components to the distribution pattern of meizoseismic effects as well
    as to the geological structure of the seismic region was found.
    The seismic region lies at the top of an anticline which was found moving
    downwards, apparently due to compressional stresses.
    Within the series of three earthquakes the progress of the destruction of
    the buildings was observed and reported. The interest is concentrated to modern
    buildings out of reinforced concrete and infill brick walls. The relatively unexpected
    rather bad performance of the later case of buildings was compared to that
    of the traditional small houses out of brick or stone masonry, the behaviour of
    which may be considered as better from what it was expected.

  3. Response of Cenozoic turbidite system to tectonic activity and sea-level change off the Zambezi Delta

    Science.gov (United States)

    Castelino, Jude A.; Reichert, Christian; Jokat, Wilfried

    2017-09-01

    Submarine fans and turbidite systems are important and sensitive features located offshore from river deltas that archive tectonic events, regional climate, sea level variations and erosional process. Very little is known about the sedimentary structure of the 1800 km long and 400 km wide Mozambique Fan, which is fed by the Zambezi and spreads out into the Mozambique Channel. New multichannel seismic profiles in the Mozambique Basin reveal multiple feeder systems of the upper fan that have been active concurrently or consecutively since Late Cretaceous. We identify two buried, ancient turbidite systems off Mozambique in addition to the previously known Zambezi-Channel system and another hypothesized active system. The oldest part of the upper fan, located north of the present-day mouth of the Zambezi, was active from Late Cretaceous to Eocene times. Regional uplift caused an increased sediment flux that continued until Eocene times, allowing the fan to migrate southwards under the influence of bottom currents. Following the mid-Oligocene marine regression, the Beira High Channel-levee complex fed the Mozambique Fan from the southwest until Miocene times, reworking sediments from the shelf and continental slope into the distal abyssal fan. Since the Miocene, sediments have bypassed the shelf and upper fan region through the Zambezi Valley system directly into the Zambezi Channel. The morphology of the turbidite system off Mozambique is strongly linked to onshore tectonic events and the variations in sea level and sediment flux.

  4. Recent tectonic activity on Mercury revealed by small thrust fault scarps

    Science.gov (United States)

    Watters, Thomas R.; Daud, Katie; Banks, Maria E.; Selvans, Michelle M.; Chapman, Clark R.; Ernst, Carolyn M.

    2016-10-01

    Large tectonic landforms on the surface of Mercury, consistent with significant contraction of the planet, were revealed by the flybys of Mariner 10 in the mid-1970s. The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission confirmed that the planet's past 4 billion years of tectonic history have been dominated by contraction expressed by lobate fault scarps that are hundreds of kilometres long. Here we report the discovery of small thrust fault scarps in images from the low-altitude campaign at the end of the MESSENGER mission that are orders of magnitude smaller than the large-scale lobate scarps. These small scarps have tens of metres of relief, are only kilometres in length and are comparable in scale to small young scarps on the Moon. Their small-scale, pristine appearance, crosscutting of impact craters and association with small graben all indicate an age of less than 50 Myr. We propose that these scarps are the smallest members of a continuum in scale of thrust fault scarps on Mercury. The young age of the small scarps, along with evidence for recent activity on large-scale scarps, suggests that Mercury is tectonically active today and implies a prolonged slow cooling of the planet's interior.

  5. New Insights into the Active Tectonics of Eastern Indonesia from GPS Measurements

    Science.gov (United States)

    Susilo, S.; Koulali Idrissi, A.; McClusky, S.; Meilano, I.; Cummins, P. R.; Tregoning, P.; Syafii, A.

    2014-12-01

    The Indonesian archipelago encompasses a wide range of tectonic environments, including island arc volcanism, subduction zones, and arc-continent collision. Many of the details of this tectonic activity are still poorly understood, especially where the Australian continent collides with Indonesia, separating the Sunda Arc in west from that at the Banda Arc in the east. While it seems clear that the Australian plate is subducted under both the Sunda and Banda Arcs, it is not clear what happens along the 1000 km -long stretch in between. The question of just where the plate motion is accommodated is of major importance to assessments of earthquake and tsunami hazard in the region. To help resolve these questions the Geospatial Information Agency of Indonesia has collaborated with the Australian National University and the Bandung Institute of Technology in a GPS campaign spanning much of eastern Indonesia, from Lombok in the west to Alor in the east. We have combined these data with those from previous campaigns, resulting in over 27 campaign and 18 continuous GPS sites being used in the analysis. The improvement in site density allowed us to develop of a more complete description of tectonic activity in this region than has been obtained in previous studies. Our preliminary results suggests that there is a relatively simple transition from subduction at the Java Trench off east Java, to a partitioned convergence along both the Timor Trough and the Flores Thrust in the Nusa Tenggara region.

  6. The composition and the source of hydrocarbons in sediments taken from the tectonically active Andaman Backarc Basin, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Chernova, T.G.; Rao, P.S.; Pikovskii, Yu.I.; Alekseeva, T.A.; Nath, B.N.; Rao, B.R.; Rao, Ch.M.

    or hydrothermal organic matter. Anthropogenic sources in region studied are of minor importance. From the results obtained, it may be deduced that the hydrocarbons in the sediments of the tectonically active part of the Andaman Basin are mainly due...

  7. GeoBioScience: Red Wood Ants as Bioindicators for Active Tectonic Fault Systems in the West Eifel (Germany).

    Science.gov (United States)

    Berberich, Gabriele; Schreiber, Ulrich

    2013-05-17

    In a 1.140 km² study area of the volcanic West Eifel, a comprehensive investigation established the correlation between red wood ant mound (RWA; Formica rufa-group) sites and active tectonic faults. The current stress field with a NW-SE-trending main stress direction opens pathways for geogenic gases and potential magmas following the same orientation. At the same time, Variscan and Mesozoic fault zones are reactivated. The results showed linear alignments and clusters of approx. 3,000 RWA mounds. While linear mound distribution correlate with strike-slip fault systems documented by quartz and ore veins and fault planes with slickensides, the clusters represent crosscut zones of dominant fault systems. Latter can be correlated with voids caused by crustal block rotation. Gas analyses from soil air, mineral springs and mofettes (CO₂, Helium, Radon and H₂S) reveal limiting concentrations for the spatial distribution of mounds and colonization. Striking is further the almost complete absence of RWA mounds in the core area of the Quaternary volcanic field. A possible cause can be found in occasionally occurring H₂S in the fault systems, which is toxic at miniscule concentrations to the ants. Viewed overall, there is a strong relationship between RWA mounds and active tectonics in the West Eifel.

  8. GeoBioScience: Red Wood Ants as Bioindicators for Active Tectonic Fault Systems in the West Eifel (Germany

    Directory of Open Access Journals (Sweden)

    Ulrich Schreiber

    2013-05-01

    Full Text Available In a 1.140 km² study area of the volcanic West Eifel, a comprehensive investigation established the correlation between red wood ant mound (RWA; Formica rufa-group sites and active tectonic faults. The current stress field with a NW-SE-trending main stress direction opens pathways for geogenic gases and potential magmas following the same orientation. At the same time, Variscan and Mesozoic fault zones are reactivated. The results showed linear alignments and clusters of approx. 3,000 RWA mounds. While linear mound distribution correlate with strike-slip fault systems documented by quartz and ore veins and fault planes with slickensides, the clusters represent crosscut zones of dominant fault systems. Latter can be correlated with voids caused by crustal block rotation. Gas analyses from soil air, mineral springs and mofettes (CO2, Helium, Radon and H2S reveal limiting concentrations for the spatial distribution of mounds and colonization. Striking is further the almost complete absence of RWA mounds in the core area of the Quaternary volcanic field. A possible cause can be found in occasionally occurring H2S in the fault systems, which is toxic at miniscule concentrations to the ants. Viewed overall, there is a strong relationship between RWA mounds and active tectonics in the West Eifel.

  9. New insights on the recent and current deformation in Central-Eastern Iran, derived from a combined tectonic and GPS analysis

    Science.gov (United States)

    Walpersdorf, A.; Manighetti, I.; Tavakoli, F.; Mousavi, Z.; Vergnolle, M.; Jadidi, A.; Hatzfeld, D.; Aghamohammadi, A.; Djamour, Y.; Nankali, H.; Sedighi, M.; Lutz, L.

    2012-04-01

    We have studied the recent to current deformation in Iran and especially Central-Eastern Iran by tightly combining tectonic and GPS analyses. Based on morphotectonic analyses of satellite images, we have identified and mapped the major active faults that dissect the entire ≈ 4500 km x 2500 km2 region that extends from Eastern Turkey to Western Afghanistan/Pakistan and hence encompasses Iran, emphasizing their large-scale organization and kinematic relationships. Doing so, we have identified the major fault systems that control the tectonics of Iran, especially in its central-eastern part. We have also analyzed the 11 years GPS record on the 92 stations deployed in central-eastern Iran in the framework of the Iranian-French collaboration. The GPS analysis reveals that all major faults identified as seismogenic in central-eastern Iran are indeed currently active and slipping at fast rates. The northerly-trending East Lut, West Lut, Kuhbanan, Anar and Deshir faults have a current right-lateral slip rate of 5.7 ± 0.9, 4.7 ± 1.7, 2.3 ± 1.9, 2.7 ± 1.3 and 0.5 ± 0.2 mm/yr, respectively, while the ≈ EW-trending Doruneh and Sedeh faults have a left-lateral current slip rate of 3.1 ± 1.8 and 1.7 ± 0.2 mm/yr, respectively. The large regions bounded by the northerly-striking faults behave as fairly rigid blocks that are all found to move towards both the N13°E ARA-EUR convergence direction and the WNW, at fast rates, in the range 6.5-12.5 and 1-5 mm/yr, respectively. Combined with the available data on the studied faults, our tectonic and geodetic results suggest that a bookshelf faulting strain transfer mechanism has been and is still operating in central-eastern Iran. The coeval dextral motion of the two major, overlapping, North Anatolian-Main Recent and Caucasus-Kopeh Dagh-Herat fault lines that embrace central-eastern Iran, induces a large-scale regional sinistral shear on either side of the region, which forces the northerly-trending right-lateral faults and

  10. Active tectonics on Lanzarote (Canary Islands) from the analysis of CGPS data

    Science.gov (United States)

    Riccardi, Umberto; Arnoso, Jose; Benavent, María Teresa; Velez, Emilio; Tammaro, Umberto; González Montesinos, Fuensanta

    2017-04-01

    We report on the analysis of about three years of CGPS data collected on a small network consisting in five permanent stations, with the largest baseline up to 40 km, spread over Timanfaya National Park in Lanzarote Island. The GPS stations are operated by different institutions, as follows: CAME is co-operated by the Institute of Geosciences (CSIC-UCM), DiSTAR and the Geodesy Research Group of University Complutense of Madrid (GRG-UCM), while LACV is operated by (CSIC-UCM and GRG-UCM). Stations HRIA, TIAS, YAIZ, belong to GRAFCAN (Cartographical Service of the Government of Canary Islands). Lanzarote is the most Northeast and the oldest island of the Canarian Archipelago (Spain), which is located on a transitional zone, a passive margin, between oceanic and continental crust. Due to some peculiarities in geochemistry and geochronology of the rocks as well as tectonics, the origin of the archipelago from a hot spot is still debated. In fact, the most recent Holocenic volcanism is scattered over the islands and the last eruption was a submarine one, occurred in October 2011 at El Hierro Island. The last eruption in Lanzarote was a 7 years voluminous eruptive cycle, occurred during the 18th century. Historical seismicity registered in the region, is customarily attributed to diffuse tectonic activity. This study is intended to contributing to shed light on the active tectonics on Lanzarote island and to separate between local and regional strain fields. With the aid of Gamit 10.6 software, we compute from the GPS observations the "ionofree" linear combinations in order to obtain the positions of the stations in ITRF2008 frame using daily sessions, and IGS precise ephemeris. The frame referencing of the network is realized by eleven IGS GPS stations. Then through a Kalman filtering procedure, implemented in GLOBK software, we obtain the final daily solutions by constraining the fiducial GPS stations to their ITRF2008 coordinates. For a reliable strain field retrieval

  11. Spatial analysis of Budovar stream catchment (Srem Loess Plateau, Serbia) in a tectonically active region

    Science.gov (United States)

    Jovanovic, Mladjen; Rvovic, Ivan; Sorak, Rada; Petrovic, Milos

    2016-04-01

    Budovar is the far longest stream on Srem Loess Plateau, with a length of a 52 km, and catchment area of 245 km2. Budovar stream drains a quite complex landscape in terms of generally flat loess plateau, with elevations decreasing gradually southeastward - from 213 m at slopes of Fru\\vska Gora Mountain to 70,9 m at the confluence with Danube river. The youngest (Pleistocene/Holocene) sedimentary formations in the catchment vary from slope loess on Fru\\vska Gora Mtn. in upper part, through typical plateau loess in middle part, and the finest bog-sediments in tectonic depressions in lower part. These deposits lie over the bog-lake-terrestrial sediments with thickness over 100 m. According the geodetic measurements, uplift of Fru\\vska Gora Mtn., which has been the strongest during the Middle Pleistocene, is still present, with rates of up to 1 mm/y in contrast of general uplift of the area, subsidence is recorded in two distinct parts of the catchment. Spatial analysis is done using a DEM, generated in ArcGIS 10.0 from the elevation points, 10 m contours and stream coverage available in 1:25.000 topographical maps. Both longitudinal and cross-section profiles of the valley reflect the influence of tectonic distortions and climatic fluctuations. Valleys in Budovar catchment have composite character - the valleys cross-sections vary from deep incised V-shape, reversed trapezoid shape and completely flat valleys in tectonic depressions. Moreover, there is almost no correlation between the shape of cross-sectional profiles and the direction of curvature of the main valley's long axis (left/right or straight), suggesting that the tectonic activity has the key role in shaping. The width of valleys in Budovar catchment area is in sharp contrast with present stream discharge, which suggests strong climate fluctuations since Upper Pleistocene. The longitudinal profiles also shows signs of kickpoints and some short reaches with increasing elevation in the flow direction. Key

  12. Coal forming environments and their relationship to tectonic activity in the Cévennes Stephanian coal basin

    Institute of Scientific and Technical Information of China (English)

    王华; 庄新国; 任建业; 张瑞生

    2002-01-01

    Coal forming environments in the tectonically controlled intermontane Stephanian Cévennes coal basin (Massif central, France) show a complex interelationship between structural and sedimentological features. The study of the general structural features and the geometry of the coal beds developed during the different stages in the evolution of the basin, and the spatial relation of the lithofacial units to the early tectonic activities, lead the authors to suggest the following model. The synsedimentary faults that occurred as both intrabasinal and marginal faults controlled not only the spatial distribution, shape and thickness of the detrital rock units and coal seams, but also caused the inversion of the tectonic style. The marginal faults exercised important controls on the geometry of the basin and the distribution of lithofacial units. However due to the subsidence of the central part of the basin and the depocenter, and the to differences in the timing and intensity of the displacement the coal enrichment zones shifted both vertically and laterally. This eventually resulted in the inversion of the whole tectonic framework from semi-graben through graben to a new semi-graben. The style and rate of the tectonic movement and basin filling that occurred in the Stephanian Cévennes coal basin were in turn closely linked with the tectonic movement in the surrounding area. Therefore the authors propose that the environment and processes of coal formation in this basin are closely linked to its tectonic evolution.

  13. Detection and Analysis of Deep Seated Gravitational Slope Deformation and Relations with the Active Tectonics

    Science.gov (United States)

    Moro, M.; Saroli, M.; Lancia, M.; Albano, M.; Lo Sardo, L.; Stramondo, S.

    2015-12-01

    Modern geomorphological investigations focused on the definition of major factors conditioning the landscape evolution. The interaction of some of these factors as the litho-structural setting, the local relief, the tectonic activity, the climatic conditions and the seismicity plays a key-role in determining large scale slope instability phenomena which display the general morphological features of deep seated gravitational deformations (DSGD). The present work aims to detect the large scale gravitational deformation and relations with the active tectonics affecting the Abruzzo Region and to provide a description of the morphologic features of the deformations by means of aerial photograph interpretation, geological/geomorphological field surveys and DInSAR data. The investigated areas are morphologically characterized by significant elevation changes due to the presence of high mountain peaks, separated from surrounding depressed areas by steep escarpments, frequently represented by active faults. Consequently, relief energy favours the development of gravity-driven deformations. These deformations seem to be superimposed on and influenced by the inherited structural and tectonic pattern, related to the sin- and post-thrusting evolution. The morphological evidences of these phenomena, are represented by landslides, sackungen or rock-flows, lateral spreads and block slides. DInSAR analysis measured deformation of the large scale gravitative phenomena previously identified through aerial-photo analysis. DSGD may evolve in rapid, catastrophic mass movements and this paroxistic evolution of the deformations may be triggered by high magnitude seismic events. These assumptions point out the great importance of mapping in detail large scale slope instability phenomena in relation to the active faults, in a perspective of land-use planning such as the Abruzzo Region characterized by a high magnitude historical seismicity.

  14. Topographyc metrics in the southern sector of the Marche foothills: implication for active tectonic analysis

    Science.gov (United States)

    Materazzi, Marco; Aringoli, Domenico; Carducci, Tamara; Cavitolo, Paolo; Farabollini, Piero; Giacopetti, Marco; Pambianchi, Gilberto; Tondi, Emanuele; Troiani, Francesco

    2016-04-01

    Quantitative geomorphic analysis can be provided a useful contribution to the study of recent tectonics. Some parameters, that quantify the channels morphology, as the Stream Length-Gradient (SL) Index (Hack, 1973) and the Steepness (Ks) Index (Flint, 1974), are generally used to detect anomalies on the expected concave-up equilibrium stream-profile, which can result in local abrupt changes in stream gradient (i.e., knickpoints) and/or broad convexities on stream long-profiles extending for tens of kilometres (i.e., knickzones). The main goal of this work is the study of the morphological and morphometrical features in the southern sector of the Marche Region, with the aim to gain new knowledge on the influences of rock resistance and rock uplift on the fluvial and topographic system. The investigated area is situated in central Italy and it extends from the axial zone of the Umbria-Marche Apennines to the Adriatic Sea, including the southern sector of the Marche Region and belongs to the foredeep domain of the Apennines orogenic system, which has affected by tectonic activity up to very recent times. The rheology of outcropping deposits doesn't allow the strain to be easily recorded at the outcrop scale. The analyses have been aimed at to test the sensitivity of both SL and Ks for evaluating active crustal deformations, acting at different wavelengths on land surface, within a low tectonically active thrust-and-fold belt. Additional purpose was the understanding of the pattern of regional differential crustal activity in the topographic arrangement of the study area In this research project two sets of analysis were conducted. References Hack J.T. 1973. Stream-profile analysis and stream-gradient index. Journal of Research of the U.S. Geological Survey, 1, 421-429. Flint J.J. 1974. Stream gradient as a function of order, magnitude and discharge. Water Resources Research, 10, 969-973.

  15. Soil radon measurements as a potential tracer of tectonic and volcanic activity

    Science.gov (United States)

    Neri, Marco; Ferrera, Elisabetta; Giammanco, Salvatore; Currenti, Gilda; Cirrincione, Rosolino; Patanè, Giuseppe; Zanon, Vittorio

    2016-04-01

    In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009–2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of 50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.

  16. Soil radon measurements as a potential tracer of tectonic and volcanic activity.

    Science.gov (United States)

    Neri, Marco; Ferrera, Elisabetta; Giammanco, Salvatore; Currenti, Gilda; Cirrincione, Rosolino; Patanè, Giuseppe; Zanon, Vittorio

    2016-04-15

    In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009-2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of 50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.

  17. Active tectonics and Quaternary landscape evolution across the western Panama block, Costa Rica, Central America

    Science.gov (United States)

    Marshall, Jeffrey Scott

    Three aspects of active tectonism are examined across central Costa Rica: (1) fault kinematics; (2) volcanic arc retreat; and (3) spatially variable coastal uplift. Diffuse faulting along the Central Costa Rica Deformed Belt (CCRDB) defines the western margin of the Panama block and aligns with the rough-smooth boundary (RSB) on the subducting Cocos plate. Sub-horizontal subduction of rough, hotspot thickened crust (Cocos Ridge and seamounts) shifts active shortening into the volcanic arc along the CCRDB. Mesoscale faults express variable kinematics across three domains: transtension in the forearc, transcurrent motion across the volcanic arc, and transpression in the back arc. Fault kinematics agree with seismicity and GPS data, and isotopic ages confirm that faulting postdates the late Neogene onset of shallow subduction. Stratigraphic correlation augmented by 40Ar/39Ar dating constrain the timing of Quaternary arc migration from the Neogene Aguacate range to the modern Cordillera Central. The Valle Central basin, between the cordilleras, filled with thick sequences of lavas, pyroclastic flows, and lahars. Middle Pleistocene drainage capture across the Aguacate arc linked the Valle Central with the Pacific slope and ash flows descended onto the coastal Orotina debris fan. Arc retreat reflects slab shallowing and enhanced tectonic erosion as rough crust entered the subduction zone. Differing subduction parameters across the RSB (crustal age, slab dip, roughness) produce marked contrasts in coastal tectonism. Varying uplift rates across coastal faults reflect sub-horizontal subduction of seamount roughness. Three groups (I--III) of fluvial terraces are correlated along the coast by isotopic ages and geomorphic characteristics. Base level fluctuations and terrace genesis reflect interaction between eustatic sea level and spatially variable rock uplift. Low uplift rates (north of RSB), yield one surface per terrace group, whereas moderate rates (south of RSB

  18. Evaluation of the relative tectonic activity in the eastern Lake Van basin, East Turkey

    Science.gov (United States)

    Sağlam Selçuk, Azad

    2016-10-01

    The eastern part of the Lake Van basin (Van region, Turkey) is controlled by reverse faults, such as the Gürpınar, Everek and Alaköy faults. These represent the major tectonic structures within the Van region and have caused many devastating earthquakes. Based on quantitative analyses, the Quaternary activity and topographic relief control of each of these faults was investigated. The Gürpınar, Everek and Alaköy faults are restricted to the southern slopes of the Güzelsu, Everek, and Karasu basins, respectively. Analyses of the mountain front sinuosity (Smf) and valley floor width-to-height ratio (Vf) suggest high activity along the Gürpınar fault, the Everek fault, and the western part of the Alaköy fault. Furthermore, based on the integration between Smf and Vf, the estimated uplift rates were observed to increase from north to south. The Gürpınar and Everek hanging-wall blocks are characterized by uplift rates of > 0.5 mm yr- 1, whereas the Alaköy fault exhibited a rate of 0.05 to 0.5 mm yr- 1. These faults produce knickpoints or knickzones, complex basin hypsometric curves, and high values of the stream length-gradient index. Based on these geomorphic analyses, it was established that the tectonic activity of both the Gürpınar and Everek faults is greater than that of the Alaköy fault.

  19. Coastal and submarine instabilities distribution in the tectonically active SW margin of the Corinth Rift (Psathopyrgos, Achaia, Greece)

    Science.gov (United States)

    Simou, Eirini; Papanikolaou, Dimitrios; Lykousis, Vasilios; Nomikou, Paraskevi; Vassilakis, Emmanuel

    2014-05-01

    The Corinth Rift, one of the most active rifts in the world as local extension trending NE-SW reaches the amount of 14±2 mm/yr, corresponds to one of the largest zones of seismically active normal faulting. The formation, growth and migration southwards of the prevailing fault systems, which evolve simultaneously with the intense morphogenetic processes, are overprinted in the age, facies and thickness of the Plio-Pleistocene sequences constructing the south margin of the western Gulf of Corinth. The dominant fault blocks, defined by east-west trending, north dipping normal faults, are accompanied by several morphological features and anomalies, noticed in both the terrestrial and the marine environment. Our main aim has been to examine how the tectonic evolution, in combination with the attendant fierce erosional and sedimentary processes, has affected the morphology through geodynamic processes expressed as failures in the wider coastal area. High resolution multibeam bathymetry in combination with the available land surface data have contributed to submarine and subaerial morphological mapping. These have been used as a basis for the detection of all those geomorphic features that indicate instabilities probably triggered, directly or indirectly, by the ongoing active tectonic deformation. The interpretation of the combined datasets shows that the southwestern margin of the Corinth Rift towards Psathopyrgos fault zone is characterized by intense coastal relief and a narrow, almost absent, continental shelf, which passes abruptly to steep submarine slopes. These steep slope values denote the effects of the most recent brittle deformation and are related to coastal and submarine instabilities and failures. High uplift rates and rapid sedimentation, indicative of the regional high-energy terrestrial and submarine environment, are subsequently balanced by the transportation of the seafloor currents, especially where slope gradients decrease, disintegrating the

  20. Statistical Modelling of Global Tectonic Activity and some Physical Consequences of its Results

    Directory of Open Access Journals (Sweden)

    Konstantin Statnikov

    2015-02-01

    Full Text Available Based on the analysis of global earthquake data bank for the last thirty years, a global tectonic activity indicator was proposed comprising a weekly globally averaged mean earthquake magnitude value. It was shown that 84% of indicator variability is a harmonic oscillation with a fundamental period of 37.2 years, twice the maximum period in the tidal oscillation spectrum (18.6 years. From this observation, a conclusion was drawn that parametric resonance (PR exists between global tectonic activity and low-frequency tides. The conclusion was also confirmed by the existence of the statistically significant PR response at the second lowest tidal frequency i.e. 182.6 days. It was shown that the global earthquake flow, with a determination factor 93%, is a sum of two Gaussian streams, nearly equally intense, with mean values of 23 and 83 events per week and standard deviations of 9 and 30 events per week, respectively. The Earth periphery to 'mean time interval between earthquakes' ratios in the first and the second flow modes described above match, by the order of magnitude, the sound velocity in the fluid (~1500 m/s and in elastic medium (5500 m/s.

  1. Coseismic landslides reveal near-surface rock strength in a high-relief tectonically active setting

    Science.gov (United States)

    Gallen, Sean F; Clark, Marin K; Godt, Jonathan W.

    2014-01-01

    We present quantitative estimates of near-surface rock strength relevant to landscape evolution and landslide hazard assessment for 15 geologic map units of the Longmen Shan, China. Strength estimates are derived from a novel method that inverts earthquake peak ground acceleration models and coseismic landslide inventories to obtain material proper- ties and landslide thickness. Aggregate rock strength is determined by prescribing a friction angle of 30° and solving for effective cohesion. Effective cohesion ranges are from 70 kPa to 107 kPa for 15 geologic map units, and are approximately an order of magnitude less than typical laboratory measurements, probably because laboratory tests on hand-sized specimens do not incorporate the effects of heterogeneity and fracturing that likely control near-surface strength at the hillslope scale. We find that strength among the geologic map units studied varies by less than a factor of two. However, increased weakening of units with proximity to the range front, where precipitation and active fault density are the greatest, suggests that cli- matic and tectonic factors overwhelm lithologic differences in rock strength in this high-relief tectonically active setting.

  2. The Relative Tectonic Activity Evaluation of Some River Basins Developing on a Fault Line: The Case of the Ganos Fault (Tekirdað)

    OpenAIRE

    Emre Özþahin

    2015-01-01

    River systems are one of the important indicators of crustal deformation in tectonically active areas. This is because; tectonic activity mostly determines the general character of valley morphology and drainage in such areas. In this regard, the relative effect of tectonic activity on topography has been evaluated more precisely in recent years through studies based on digital measurements that employ various morphometric parameters (geomorphic indices). The present study aims to make a tect...

  3. Active landsliding and landscape denudation in response to transient tectonic uplift, Northern California.

    Science.gov (United States)

    Bennett, G. L.; Roering, J. J.; Miller, S. R.; Kirby, E.; Schmidt, D. A.

    2014-12-01

    The northern Californian Coast ranges present a unique area to study landscape response to transient tectonic uplift. Studies have shown that an increase in uplift may be balanced by the rate of landsliding in settings of steady uplift. However, the landsliding response to transient tectonic uplift remains to be elucidated. The Californian Coast ranges are shaped by the northward migration of the Mendocino Triple Junction (MTJ), which geodynamic modeling suggests produces a transient double-humped uplift field. A major research question is whether we can detect a signature of this transient tectonic uplift in landslide activity and document how the channel network communicates this signal to hillslopes. Using air photos and Worldview imagery, we manually mapped more than 2000 earthflows and debris slides in the Eel and surrounding catchments that span the ~400 km-long region. The velocities of active earthflows were estimated by visually tracking features between images spanning 1993 to 2013. We mapped channel steepness from 10m NED DEMs in Topotoolbox 2 and developed a new tool to automatically define knickpoints along the channel network. Earthflows occur almost exclusively in a band of Franciscan mélange oriented along the MTJ transect whilst debris slides are more evenly distributed by lithology. Both earthflows and debris slides are clustered in the Eel catchment around the proposed uplift peaks and are largely absent outside of these zones. Within these areas of high landslide densities, we observe peaks in active earthflows adjacent to peaks in dormant earthflows to the south, suggesting that the signature of earthflow activity remains for a period of time once the uplift peak has passed. Landslide density, mean landslide area, and earthflow velocity all increase rapidly above threshold values of channel steepness and local relief. In the Eel catchment, where the zone of rapid uplift is commencing, landslides, particularly earth flows, are concentrated

  4. Active inrush-current limiter

    Science.gov (United States)

    Kichak, R. A.

    1977-01-01

    By stretching turn-on time from approximately 1 to 200 ms, effects of inrush current (and of associated large current spikes) and current rate of rise (dl/dt) are made potentially less severe. Limiter arrangement consists of time-variable impedance connected in series between input dc power source return and power circuit of converter.

  5. Tectonic activity revealed by morphostructural analysis: Development of the Sierra de la Candelaria range, northwestern Argentina

    Science.gov (United States)

    Barcelona, H.; Peri, G.; Tobal, J.; Sagripanti, L.; Favetto, A.

    2014-12-01

    The tectonically active broken foreland of NW Argentina is a recent analog of the eastern margin of the Puna plateau during Mio-Pliocene times and likely of other broken forelands worldwide. In order to evaluate active tectonism in the broken foreland of the NW Argentine Andes, we examined the complex geomorphology in the vicinity of the basement-cored Sierra de la Candelaria range at ˜26°S and deciphered multiple episodes of crustal deformation spanning the Pliocene to the Quaternary. Digital elevation models, satellite images and geological data within a GIS environment allowed us to analyze the terrain, drainage networks, river dynamics and structure, as well as to obtain detailed geomorphological mapping, active tectonic indices, longitudinal river profiles and structural sections. Three morphostructural segments were defined based on the structural features, the differential vertical dissection pattern over the basement, the faulted Pliocene to recent deposits, the stepwise propagation of anticlines and the distortion over the fluvial system. By combining the several lines of evidence, we concluded that the Sierra de la Candelaria range was subjected to a multi-stage development. The first stage uplifted the central segment concomitant with the formation of the surrounding ranges and with the main partition phase of the foreland. After a significant time lapse, the mountain range was subjected to southward thick-skinned growth and northward growth via stepwise thin-skinned deformation and exerted control over the dynamics of the Río Rosario. Taking into account the surrounding basins and ranges of the Sierra de la Candelaria, the southern Santa Bárbara System is characterized by partially isolated intramontane basins (Choromoro and Rosario) limited by shielded ranges that caused moisture block and shows continuous deformation. These features were related to early stages of a broken foreland evolution model and modern analogs were found at the northern

  6. The Geomorphological Evolution of a Landscape in a Tectonically Active Region: the Sennwald Landslide

    Science.gov (United States)

    Aksay, Selçuk; Ivy-Ochs, Susan; Hippe, Kristina; Graemiger, Lorenz; Vockenhuber, Christof

    2016-04-01

    earthquake activity shows that this region is tectonically still active (Mosar, 1999) with numerous earthquakes. The exposure ages imply that the rock failure occurred during the middle Holocene, a period of increased neotectonic activity in Eastern Alps suggested by Prager et al. (2007). This time period also coincides with notably wet climate, which has been suggested as an important trigger for landslides around this age across the Alps (Zerathe et al., 2014).

  7. Sedimentology of seismo-turbidites off the Cascadia and northern California active tectonic continental margins, Pacific Ocean

    Science.gov (United States)

    Gutierrez Pastor, Julia; Nelson, Hans; Goldfinger, Chris; Escutia, Carlota

    2013-04-01

    Holocene turbidites from turbidite channel systems along the active tectonic continental margins of the Cascadia subduction zone (offshore Vancouver Island to Mendocino Triple Junction) and the northern San Andreas Transform Fault (the Triple Junction to San Francisco Bay), have been analyzed for sedimentologic features related to their seismic origin. Centimeter thick silt/sand beds (turbidite base) capped by mud layers (turbidite tail) and interbedded with hemipelagic silty clay intervals with high biogenic content have been characterized by visual core descriptions, grain-size analysis, X-ray radiographs and physical properties. Along the northern California margin in upstream single tributary canyons and channels, most turbidites are uni-pulsed (classic fining up) whereas downstream below multiple tributary canyon and channel confluences, most deposits are stacked turbidites. Because each set of stacked turbidites has no hemipelagic sediment between each turbidite unit and each unit has a distinct mineralogy from a different tributary canyon, we interpret that a stacked turbidite is deposited by several coeval turbidity currents fed by multiple tributary canyons and channels with synchronous triggering from a single San Andreas Fault earthquake. The Cascadia margin is characterized by individual multi-pulsed turbidites that contain multiple coarse-grained sub-units without hemipelagic sediment between pulses. Because the number and character of multiple coarse-grained pulses for each correlative multi-pulsed turbidite is almost always constant both upstream and downstream in different channel systems for 600 km along the margin,we interpret that the earthquake shaking or aftershock signature is usually preserved, for the much stronger Cascadia (≥9 Mw) compared to weaker California (≥8Mw) earthquakes, which result in upstream uni-pulsed turbidites and downstream stacked turbidites. Consequently, both the strongest (≥9 Mw) great earthquakes and downstream

  8. Hydrothermal fluids circulation and travertine deposition in an active tectonic setting: Insights from the Kamara geothermal area (western Anatolia, Turkey)

    Science.gov (United States)

    Brogi, Andrea; Alçiçek, M. Cihat; Yalçıner, Cahit Çağlar; Capezzuoli, Enrico; Liotta, Domenico; Meccheri, Marco; Rimondi, Valentina; Ruggieri, Giovanni; Gandin, Anna; Boschi, Chiara; Büyüksaraç, Aydin; Alçiçek, Hülya; Bülbül, Ali; Baykara, Mehmet Oruç; Shen, Chuan-Chou

    2016-06-01

    Coexistence of thermal springs, travertine deposits and tectonic activity is a recurring feature for most geothermal areas. Although such a certainty, their relationships are debated mainly addressing on the role of the tectonic activity in triggering and controlling fluids flow and travertine deposition. In this paper, we present the results of an integrated study carried out in a geothermal area located in western Anatolia (Turkey), nearby the well-known Pamukkale area (Denizli Basin). Our study focused on the relationships among hydrothermal fluids circulation, travertine deposition and tectonic activity, with particular emphasis on the role of faults in controlling fluids upwelling, thermal springs location and deposition of travertine masses. New field mapping and structural/kinematics analyses allowed us to recognize two main faults systems (NW- and NE-trending), framed in the Neogene-Quaternary extensional tectonic evolution of western Anatolia. A geo-radar (GPR) prospection was also provided in a key-area, permitting us to reconstruct a buried fault zone and its relationships with the development of a fissure-ridge travertine deposit (Kamara fissure-ridge). The integration among structural and geophysical studies, fluids inclusion, geochemical, isotopic data and 230 Th/238 U radiometric age determination on travertine deposits, depict the characteristics of the geothermal fluids and their pathway, up to the surface. Hydrological and seismological data have been also taken in account to investigate the relation between local seismicity and fluid upwelling. As a main conclusion we found strict relationships among tectonic activity, earthquakes occurrence, and variation of the physical/chemical features of the hydrothermal fluids, presently exploited at depth, or flowing out in thermal springs. In the same way, we underline the tectonic role in controlling the travertine deposition, making travertine (mainly banded travertine) a useful proxy to reconstruct the

  9. Active tectonic deformation along rejuvenated faults in tropical Borneo: Inferences obtained from tectono-geomorphic evaluation

    Science.gov (United States)

    Mathew, Manoj Joseph; Menier, David; Siddiqui, Numair; Kumar, Shashi Gaurav; Authemayou, Christine

    2016-08-01

    The island of Borneo is enveloped by tropical rainforests and hostile terrain characterized by high denudation rates. Owing to such conditions, studies pertaining to neotectonics and consequent geomorphic expressions with regard to surface processes and landscape evolution are inadequately constrained. Here we demonstrate the first systematic tectono-geomorphic evaluation of north Borneo through quantitative and qualitative morphotectonic analysis at sub-catchment scale, for two large drainage basins located in Sarawak: the Rajang and Baram basins. The extraction of morphometric parameters utilizing digital elevation models arranged within a GIS environment focuses on hypsometric curve analysis, distribution of hypsometric integrals through spatial autocorrelation statistics, relative uplift values, the asymmetry factor and the normalized channel steepness index. Hypsometric analysis suggests a young topography adjusting to changes in tectonic boundary conditions. Autocorrelation statistics show clusters of high values of hypsometric integrals as prominent hotspots that are associated with less eroded, young topography situated in the fold and thrust belts of the Interior Highlands of Borneo. High channel steepness and gradients (> 200 m0.9) are observed in zones corresponding to the hotspots. Relative uplift values reveal the presence of tectonically uplifted blocks together with relatively subsided or lesser uplifted zones along known faults. Sub-catchments of both basins display asymmetry indicating tectonic tilting. Stream longitudinal profiles demonstrate the presence of anomalies in the form of knickzones without apparent lithological controls along their channel reaches. Surfaces represented by cold spots of low HI values and low channel gradients observed in the high elevation headwaters of both basins are linked to isolated erosional planation surfaces that could be remnants of piracy processes. The implication of our results is that Borneo experiences

  10. Along-strike Deformation in Quaternary Valleys of Tropical NW Borneo: Implications for Active Tectonics, Seismicity and Geomorphology

    Science.gov (United States)

    Sautter, B.; Mathew, M. J.; Menier, D.; Pubellier, M. F.; Sapin, F.; Siddiqui, N.

    2015-12-01

    In the wee hours of 5th June, 2015, NW Borneo was jolted by a 6.0 magnitude earthquake, caused by fault movement at a shallow depth of 10 km. The quake that originated from near the foot of the picturesque Mount Kinabalu, Sabah, was felt as far as 350 km away from the epicentre and has produced more than 90 aftershocks to date; ranging in magnitudes from 1.6 to 5.2. Although the geologically complex NW Borneo has experienced more than 60 mainshocks and numerous aftershocks since 1970 to present; research pertaining to active tectonics, morphotectonics analysis and subsequent geomorphic response to resulting transient dynamic topography remains inadequate.Here, we show evidences of active tectonics in tropical Sabah, NW Borneo, using morphometric indices, geomorphic indicators and report our results of morphotectonic analysis and consequent feedback of landscape and topography. Results from stream length gradient index, normalized channel steepness index and spatial distribution of hypsometric integral showed evidences of fault rejuvenation during Quaternary and recent periods. River longitudinal profiles showed the presence of several knickpoints indicating fault reactivations as the study area lacks lithological contrasts and similar climatic conditions along the channel reach. Field survey revealed the presence of highly elevated Quaternary fluvial terraces illustrating recent and important tectonic uplift rates in the trend of the exhumation rates calculated on Mt. Kinabalu by means of thermochronology. The uplifted terraces show a positive correlation with geomorphic analysis along the main valleys and other areas of active tectonics. Our analysis show the competition between important uplifts related to the dynamics of the NW Borneo Wedge and active normal faulting. These faults are in trend to the major earthquakes that occurred recently in this area, which have a normal faulting mechanism. The cause of the mechanism for recent tectonism and/or decoupling

  11. Programmable Current-Mode Universal Active Filters Employing Current Conveyors

    OpenAIRE

    Muhammad Taher Abuelma'atti

    1998-01-01

    Novel current-mode active filter circuits using current-conveyors are presented. The proposed circuits can realize all standard second-order filter functions. The circuits enjoy high output impedances and can, therefore, be easily cascaded to produce higher order filters. Moreover, the realized filter function can be easily programmed using at most a 13-bit digital number without changing the circuit topology.

  12. Active faulting and transpression tectonics along the plate boundary in North Africa

    Directory of Open Access Journals (Sweden)

    Mustapha Meghraoui

    2013-01-01

    Full Text Available We present a synthesis of the active tectonics of the northern Atlas Mountains, and suggest a kinematic model of transpression and block rotation that illustrates the mechanics of this section of the Africa–Eurasia plate boundary. Neotectonic structures and significant shallow seismicity (with Mw >5.0 indicate that coeval E-W-trending, right-lateral faulting and NE-SW, thrust-related folding result from oblique convergence at the plate boundary, which forms a transpressional system. The strain distribution obtained from fault–fold structures and P axes of focal mechanism solutions, and the geodetic (NUVEL-1 and GPS convergence show that the shortening and convergence directions are not coaxial. The transpressional strain is partitioned along the strike and the quantitative description of the displacement field yields a compression-to-transcurrence ratio varying from 33% near Gibraltar, to 50% along the Tunisian Atlas. Shortening directions oriented NNE and NNW for the Pliocene and Quaternary, respectively, and the S shape of the Quaternary anticline axes, are in agreement with the 2.24˚/Myr to 3.9˚/Myr modeled clockwise rotation of the small tectonic blocks and with the paleomagnetic data. The convergence between Africa and Eurasia is absorbed along the Atlas Mountains at the upper crustal level, by means of thrusting above decollement systems, which are controlled by subdued transcurrent faults. The Tell Atlas of northwest Algeria, which has experienced numerous large earthquakes with respect to the other regions, is interpreted as a restraining bend that localizes the strain distribution along the plate boundary.

  13. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G. [UNR; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J.; Pullammanappallil, S. [Optim

    2016-08-01

    Amy Eisses, Annie M. Kell, Graham Kent, Neal W. Driscoll, Robert E. Karlin, Robert L. Baskin, John N. Louie, Kenneth D. Smith, Sathish Pullammanappallil, 2011, Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract NS14A-08.

  14. Quaternary volcano-tectonic activity in the Soddo region, western margin of the Southern Main Ethiopian Rift

    NARCIS (Netherlands)

    Corti, G.; Sani, F.; Philippon, M.; Sokoutis, D.; Willingshofer, E.; Molin, P.

    2013-01-01

    We present an analysis of the distribution, timing, and characteristics of the volcano-tectonic activity on the western margin of the Southern Main Ethiopian Rift in the Soddo area (latitudes between ~7°10'N and ~6°30'N). The margin is characterized by the presence of numerous normal faults, with li

  15. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G. [UNR; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim

    2016-08-01

    Amy Eisses, Annie M. Kell, Graham Kent, Neal W. Driscoll, Robert E. Karlin, Robert L. Baskin, John N. Louie, Kenneth D. Smith, Sathish Pullammanappallil, 2011, Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract NS14A-08.

  16. Performative Tectonics

    DEFF Research Database (Denmark)

    Holst, Malene Kirstine; Mullins, Michael; Kirkegaard, Poul Henning

    2010-01-01

    This paper studies two digital generative tools in terms of Performative Tectonics. Performative Tectonics is a term developed in the paper, which links the contemporary development of digital tools to the tectonic tradition of architecture. Within the theoretical framework of this definition...

  17. Geomorphological features of active tectonics and ongoing seismicity of northeastern Kumaun Himalaya, Uttarakhand, India

    Indian Academy of Sciences (India)

    Vivekanand Pathak; Charu C Pant; Gopal Singh Darmwal

    2015-08-01

    The northeastern part of Kumaun Lesser Himalaya, Uttarakhand, India, lying between the rupture zones of 1905, Kangra and 1934, Bihar–Nepal earthquakes and known as ‘central seismic gap’ is a segment of an active fault known to produce significant earthquakes and has not slipped in an unusually long time when compared to other segments. The studied section forms a part of this seismic gap and is seismically an active segment of the Himalayan arc, as compared to the remaining part of the Kumaun Lesser Himalaya and it is evident by active geomorphological features and seismicity data. The geomorphological features of various river valley transects suggest that the region had a history of tectonic rejuvenation which is testified by the deposition of various levels of terraces and their relative uplift, shifting and ponding of river channels, uplifted potholes, triangular facets on fault planes, fault scarps, etc. Further, the seismic data of five-station digital telemetered seismic network along with two stand alone systems show the distribution of earthquakes in or along the analyzed fault transects. It is observed that the microseismic earthquakes (magnitude 1.0–3.0) frequently occur in the region and hypocenters of these earthquakes are confined to shallow depths (10–20 km), with low stress drop values (1.0–10 bar) and higher peak ground velocity (PGV). The cluster of events is observed in the region, sandwiched between the Berinag Thrust (BT) in south and Main Central Thrust (MCT) in north. The occurrences of shallow focus earthquakes and the surface deformational features in the different river valley transect indicates that the region is undergoing neotectonic rejuvenation. In absence of chronology of the deposits it is difficult to relate it with extant seismicity, but from the geomorphic and seismic observations it may be concluded that the region is still tectonically active. The information would be very important in identifying the areas of

  18. Quaternary active tectonic structures in the offshore Bajo Segura basin (SE Iberian Peninsula - Mediterranean Sea)

    Science.gov (United States)

    Perea, H.; Gràcia, E.; Alfaro, P.; Bartolomé, R.; Lo Iacono, C.; Moreno, X.; Masana, E.; Event-Shelf Team

    2012-10-01

    The Bajo Segura fault zone (BSFZ) is the northern terminal splay of the Eastern Betic shear zone (EBSZ), a large left-lateral strike-slip fault system of sigmoid geometry stretching more than 450 km from Alicante to Almería. The BSFZ extends from the onshore Bajo Segura basin further into the Mediterranean Sea and shows a moderate instrumental seismic activity characterized by small earthquakes. Nevertheless, the zone was affected by large historical earthquakes of which the largest was the 1829 Torrevieja earthquake (IEMS98 X). The onshore area of the BSFZ is marked by active transpressive structures (faults and folds), whereas the offshore area has been scarcely explored from the tectonic point of view. During the EVENT-SHELF cruise, a total of 10 high-resolution single-channel seismic sparker profiles were obtained along and across the offshore Bajo Segura basin. Analysis of these profiles resulted in (a) the identification of 6 Quaternary seismo-stratigraphic units bounded by five horizons corresponding to regional erosional surfaces related to global sea level lowstands; and (b) the mapping of the active sub-seafloor structures and their correlation with those described onshore. Moreover, the results suggest that the Bajo Segura blind thrust fault or the Torrevieja left-lateral strike-slip fault, with prolongation offshore, could be considered as the source of the 1829 Torrevieja earthquake. These data improve our understanding of present deformation along the BSFZ and provide new insights into the seismic hazard in the area.

  19. The feedback between active tectonics, fluid flow and mineralization in an Andean geotermal reservoir

    Science.gov (United States)

    Reich, M.; Arancibia, G.; Perez, P.; Sanchez, P.; Cembrano, J. M.; Stimac, J. A.; Lohmar, S.

    2012-12-01

    In the Andean Cordillera of Central-Southern Chile, geothermal resources occur in close spatial relationship with active volcanism. The nature of the relationship between tectonics and volcanism in this region is the result of interaction between the crustal structures of the basement and the ongoing regional stress field, which is primarily controlled by the oblique convergence of the Nazca and South America Plates. Between 39° and 46°S, the volcanic and geothermal activity is controlled by the NNE-trending, 1,000 km long Liquiñe-Ofqui Fault Zone (LOFZ), an intra-arc dextral strike-slip fault system. Although there is consensus that volcanism (and hence geothermal activity) in southern Chile is largely controlled by the regional-scale tectonic stress field and architecture of the volcanic arc, there is limited scientific information about the role of local kinematic conditions on fluid flow and mineralization during the development and evolution of geothermal reservoirs. In this report, we present the preliminary results of an undergoing structural, mineralogical and geochemical study of the Tolhuaca geothermal system in southern Chile. The Tolhuaca geothermal reservoir formed as a liquid-dominated hydrothermal system, where shallow upflow resulted in near-boiling temperatures in a roughly horizontal liquid reservoir at 100-200 m depth (Melosh et al., 2010, 2012). In an early stage of evolution, hydrothermal brecciation and phase-separation (boiling) episodes penetrated at least 950 m depth into the deeper reservoir, and boiling was followed by steam-heated water invasion that cooled the reservoir. In a later stage, the preliminary conceptual model involves boiling and reheating of the reservoir, forming a system with deep hot brines that is connected to the shallow steam zone by an upflow conduit that is characterized by high-temperature mineralogy. The structural analysis of veins, fault-veins and faults of the Tol-1 drillcore (~1080 m depth) provide insights

  20. Pore-pressure sensitivities to dynamic strains: observations in active tectonic regions

    Science.gov (United States)

    Barbour, Andrew J.

    2015-01-01

    Triggered seismicity arising from dynamic stresses is often explained by the Mohr-Coulomb failure criterion, where elevated pore pressures reduce the effective strength of faults in fluid-saturated rock. The seismic response of a fluid-rock system naturally depends on its hydro-mechanical properties, but accurately assessing how pore-fluid pressure responds to applied stress over large scales in situ remains a challenging task; hence, spatial variations in response are not well understood, especially around active faults. Here I analyze previously unutilized records of dynamic strain and pore-pressure from regional and teleseismic earthquakes at Plate Boundary Observatory (PBO) stations from 2006 through 2012 to investigate variations in response along the Pacific/North American tectonic plate boundary. I find robust scaling-response coefficients between excess pore pressure and dynamic strain at each station that are spatially correlated: around the San Andreas and San Jacinto fault systems, the response is lowest in regions of the crust undergoing the highest rates of secular shear strain. PBO stations in the Parkfield instrument cluster are at comparable distances to the San Andreas fault (SAF), and spatial variations there follow patterns in dextral creep rates along the fault, with the highest response in the actively creeping section, which is consistent with a narrowing zone of strain accumulation seen in geodetic velocity profiles. At stations in the San Juan Bautista (SJB) and Anza instrument clusters, the response depends non-linearly on the inverse fault-perpendicular distance, with the response decreasing towards the fault; the SJB cluster is at the northern transition from creeping-to-locked behavior along the SAF, where creep rates are at moderate to low levels, and the Anza cluster is around the San Jacinto fault, where to date there have been no statistically significant creep rates observed at the surface. These results suggest that the strength

  1. Tectonic Vocabulary & Materialization

    DEFF Research Database (Denmark)

    Hvejsel, Marie Frier; Beim, Anne; Bundgaard, Charlotte

    2015-01-01

    to establish a Nordic Network for Research and Teaching in Tectonics is currently forming. This paper seeks to jointly reflect upon these initiatives in order to bring them further, with the intention to clad a discourse on the future of tectonic architectural research that addresses the conditions of everyday...... architectural practice. In this matter the paper focuses on the need to juxtapose theoretical studies, to bring the present vocabulary of the tectonic further, as well as to spur further practical experiments enabling theory to materialize in the everyday of the current practice....

  2. Late Quaternary loess landscape evolution on an active tectonic margin, Charwell Basin, South Island, New Zealand

    Science.gov (United States)

    Hughes, Matthew W.; Almond, Peter C.; Roering, Joshua J.; Tonkin, Philip J.

    2010-10-01

    Loess deposits constitute an important archive of aeolian deposition reflecting wider patterns of glacial atmospheric circulation, and more localised interactions between riverine source areas, loess trapping efficiency and geomorphic controls on erosion rate. Conceptual models have been formulated to explain the coeval evolution of loess mantles and associated landscapes (loess landscape models) but none apply to areas of tectonically induced base-level lowering. This study uses an age sequence of alluvial fill terraces in the Charwell Basin, north-eastern South Island New Zealand, which straddles the transpressive Hope Fault, to investigate geomorphic controls on loess landscape evolution in an active tectonic region. We hypothesize that the more evolved drainage networks on older terraces will more effectively propagate base-level lowering by way of a greater areal proportion of steep and convex hillslopes and a smaller proportion of non-eroding interfluves. Eventually, as the proportion of interfluves diminishes and hillslope convexity increases, terraces shift from being net loess accumulators to areas of net loess erosion. We investigate the nature of erosion and the geomorphic thresholds associated with this transition. Morphometric analysis of alluvial terraces and terrace remnants of increasing age demonstrated geomorphic evolution through time, with a decrease in extent of original planar terrace tread morphology and an increase in frequency of steeper slopes and convexo-concave land elements. The number of loess sheets and the thickness of loess increased across the three youngest terraces. The next oldest (ca. 150 ka) terrace remnant had the greatest maximum number of loess sheets (3) and loess thickness (8 m) but the loess mantle was highly variable. A detailed loess stratigraphic analysis and the morphometric analysis place this terrace in a transition between dominantly planar, uniformly loess-mantled landforms and loess-free ridge and valley terrain

  3. Active tectonics of the Northern Rif (Morocco) from geomorphic and geochronological data

    Science.gov (United States)

    Poujol, A.; Ritz, J.-F.; Tahayt, A.; Vernant, P.; Condomines, M.; Blard, P.-H.; Billant, J.; Vacher, L.; Tibari, B.; Hni, L.; Idrissi, A. Koulali

    2014-07-01

    We present results of a geomorphological and morphotectonic analysis of the northeastern part of the Rif. We show that the present day kinematics of the Rif is characterized by active deformation along the Trougout and Nekor faults in the North-East. Digital Elevation Models of offset drainage features (streams, fluvial terraces) allow determining a normal-left-lateral motion along the Trougout fault and a left-lateral strike-slip motion along the Nekor fault. Preliminary 3He cosmogenic dates of tectonic markers yield vertical and horizontal slip rates of ∼0.9 mm/yr and ∼0.5 mm/yr, respectively along the Trougout fault. The present-day localized transtension seen in the north-eastern Rif morphology (Ras Tarf) is coeval with uplifted marine terraces near the Al Hoceima Bay. U/Th dating of shells yield an average uplift rate of ∼0.2 mm/yr during the past 500 ka. These data show that active transtension in the northeastern Rif is also associated with uplift. These new morphotectonic constraints are consistent with the GPS measurements showing southwestward overall motion of most of the Rif belt with respect to stable Africa.

  4. Insights into the evolution of tectonically-active glaciated mountain ranges from digital elevation model analyses

    Science.gov (United States)

    Brocklehurst, S. H.; Whipple, K. X.

    2003-12-01

    Glaciers have played an important role in the development of most active mountain ranges around the world during the Quaternary, but the interaction between glacial erosion (as modulated by climate change) and tectonic processes is poorly understood. The so-called glacial buzzsaw hypothesis (Brozovic et al., 1997) proposes that glaciers can incise as rapidly as the most rapid rock uplift rates, such that glaciated landscapes experiencing different rock uplift rates but the same snowline elevation will look essentially the same, with mean elevations close to the snowline. Digital elevation model-based analyses of the glaciated landscapes of the Nanga Parbat region, Pakistan, and the Southern Alps, New Zealand, lend some support to this hypothesis, but also reveal considerably more variety to the landscapes of glaciated, tectonically-active mountain ranges. Larger glaciers in the Nanga Parbat region maintain a low downvalley gradient and valley floor elevations close to the snowline, even in the face of extremely rapid rock uplift. However, smaller glaciers steepen in response to rapid uplift, similar to the response of rivers. A strong correlation between the height of hillslopes rising from the cirque floors and rock uplift rates implies that erosion processes on hillslopes cannot initially keep up with more rapid glacial incision rates. It is these staggering hillslopes that permit mountain peaks to rise above 8000m. The glacial buzzsaw hypothesis does not describe the evolution of the Southern Alps as well, because here mean elevations rise in areas of more rapid rock uplift. The buzzsaw hypothesis may work well in the Nanga Parbat region because the zone of rapid rock uplift is structurally confined to a narrow region. Alternatively, the Southern Alps may not have been rising sufficiently rapidly or sufficiently long for the glacial buzzsaw to be imposed outside the most rapidly uplifting region, around Mount Cook. The challenge now is to understand in detail

  5. Peculiar Active-Tectonic Landscape Within the Sanctuary of Zeus at Mt. Lykaion (Peloponnese, Greece)

    Science.gov (United States)

    Davis, G. H.

    2008-12-01

    The Sanctuary of Zeus (Mt. Lykaion) lies in the Peloponnese within the Pindos fold and thrust belt. It is the object of investigation of the Mt. Lykaion Excavation and Survey (http://lykaionexcavation.org/). Mt. Lykaion is a thrust klippe, on the summit of which is an upper sanctuary marked by an ash altar, temenos, and column bases. Earliest objects recovered from the ash altar go back to 3000 BCE, leading Dr. David Romano (University of Pennsylvania), a principal leader of the project, to conclude that worship of divinities on the summit is ancient. Detailed structural geological mapping reveals one dimension of the "power" of the site. Crisscrossing the upper sanctuary are scree bands that mark the traces of active normal faults, which are expressions of tectonic stretching of the Aegean region. The scree bands, composed of cinder-block-sized limestone blocks, range up to 10 m in outcrop breadth, 100 m in length, and 5 m in thickness. Though discontinuous, most of the scree bands lie precisely on the traces of through-going faults, which cut and displace the sedimentary formations of the Pindos group. Some cut the thrust fault, whose elliptical trace defines the Lykaion klippe. What makes the scree bands of this active-tectonic landscape "peculiar" is that there are no cliffs from which the scree descends. Rather, the bands of scree occur along flanks of smooth, rounded hillslopes and ridges. The scree bands coincide with modest steps in the topography, ranging from tens of centimeters to several tens of meters. The specific bedrock formation where the bands are best developed is an Upper Cretaceous limestone whose average platy-bedding thickness (approximately 20 cm) matches closely the average joint spacing. The limestone has little mechanical integrity. It cannot support itself as a scarp footwall and instead collapses into a pile of scree, whose upper-surface inclination conforms to a stable angle of repose. Evidence of the contemporary nature of this

  6. Quantifying submarine landslide processes driven by active tectonic forcing: Cook Strait submarine canyon, New Zealand.

    Science.gov (United States)

    Mountjoy, J. J.; Barnes, P. M.; Pettinga, J. R.

    2006-12-01

    The Cook Strait submarine canyon system is a multi-branched, deeply incised and highly sinuous feature of New Zealand's active margin, covering some 1500km2 of sea floor between the North and South Islands and spanning water depths of between 50 and 2700m. The canyon occurs at the transition from the westward dipping oblique subduction zone adjacent to the SE North Island and the zone of continental transpression in NE South Island. The recent acquisition of high resolution (5-10m) SIMRAD EM300 bathymetric data allows active tectonic and geomorphic processes to be assessed and quantified at a level of detail previously not possible. While multiple active submarine fault traces have been identified in the Cook Strait by previous studies, quantitative information on their activity has been limited. Cook Strait is structurally characterized by westward dipping thrust faults and E-W trending dextral strike slip faults. The multiple large magnitude high frequency earthquake sources define zones of very high ground shaking expected to contribute to triggering of extensive submarine slope failures. Landslide activity within the canyon system is widespread and represents the dominant mass movement process affecting canyon heads and walls, redistributing material into valley fills. Complexes of large (km3) multi-stepped, deep-seated (100m) translational bedding plane failures represented by gently sloping (<3°) evacuated slide-scar areas with associated blocky valley fill deposits are numerous. Steep catchment heads, channel walls and the leading edges of asymmetric thrust-fault driven anticlines are dominated by gulley and rill systems with associated eroded and/or incipient slump features. Large (107m3+) slide blocks are recognized in discrete failures with quantifiable displacement vectors. Tsunamigenic landslides in this environment are inevitable. This study will provide quantification of landslide models including triggering mechanisms, discrete geometries and

  7. Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska

    Science.gov (United States)

    SauberRosenberg, Jeanne M.; Molnia, Bruce F.

    2003-01-01

    Across southern Alaska the northwest directed subduction of the Pacific plate is accompanied by accretion of the Yakutat terrane to continental Alaska. This has led to high tectonic strain rates and dramatic topographic relief of more than 5000 meters within 15 km of the Gulf of Alaska coast. The glaciers of this area are extensive and include large glaciers undergoing wastage (glacier retreat and thinning) and surges. The large glacier ice mass changes perturb the tectonic rate of deformation at a variety of temporal and spatial scales. We estimated surface displacements and stresses associated with ice mass fluctuations and tectonic loading by examining GPS geodetic observations and numerical model predictions. Although the glacial fluctuations perturb the tectonic stress field, especially at shallow depths, the largest contribution to ongoing crustal deformation is horizontal tectonic strain due to plate convergence. Tectonic forces are thus the primary force responsible for major earthquakes. However, for geodetic sites located Glacier s most recent surge cycle are large enough to cause discernible surface displacements. Additionally, ice mass fluctuations associated with the surge cycle can modify the short-term seismicity rates in a local region. For the thrust faulting environment of the study region a large decrease in ice load may cause an increase in seismic rate in a region close to failure whereas ice loading may inhibit thrust faulting.

  8. Formation and evolution of yardangs activated by Late Pleistocene tectonic movement in Dunhuang, Gansu Province of China

    Science.gov (United States)

    Wang, Yanjie; Wu, Fadong; Zhang, Xujiao; Zeng, Peng; Ma, Pengfei; Song, Yuping; Chu, Hao

    2016-12-01

    Developed in the Anxi-Dunhuang basin, the yardangs of Dunhuang (western China) are clearly affected by tectonic movement. Based on fieldwork, this study ascertained three levels of river terrace in the area for the first time. Through the analysis of river terraces formation and regional tectonic movement, the study ascertained that the river terraces were formed mainly by Late Pleistocene tectonic uplift, which had activated the evolution of yardangs in the study area. By electron spin resonance (ESR) dating and optically stimulated luminescence (OSL) dating, the starting time and periodicity of the evolution of the yardangs were determined. The river terraces designated T3, T2 and T1 began to evolve at 109.0 ˜98.5, 72.9 ˜66.84 and 53.2 ˜38.0 kaBP, respectively, which is the evidence of regional neotectonic movement. And, the formation of the yardangs was dominated by tectonic uplift during the prenatal stage and mainly by wind erosion in the following evolution, with relatively short stationary phases. This research focused on the determination of endogenic processes of yardangs formation, which would contribute to further understanding of yardangs formation from a geological perspective and promote further study of yardang landform.

  9. Formation and evolution of yardangs activated by Late Pleistocene tectonic movement in Dunhuang, Gansu Province of China

    Indian Academy of Sciences (India)

    Yanjie Wang; Fadong Wu; Xujiao Zhang; Peng Zeng; Pengfei Ma; Yuping Song; Hao Chu

    2016-12-01

    Developed in the Anxi-Dunhuang basin, the yardangs of Dunhuang (western China) are clearly affected by tectonic movement. Based on fieldwork, this study ascertained three levels of river terrace in the area for the first time. Through the analysis of river terraces formation and regional tectonic movement, the study ascertained that the river terraces were formed mainly by Late Pleistocene tectonic uplift, which had activated the evolution of yardangs in the study area. By electron spin resonance (ESR) dating and optically stimulated luminescence (OSL) dating, the starting time and periodicity of the evolution of the yardangs were determined. The river terraces designated T3, T2 and T1 began to evolve at 109.0∼98.5, 72.9∼66.84 and 53.2∼38.0 kaBP, respectively, which is the evidence of regional neotectonic movement.And, the formation of the yardangs was dominated by tectonic uplift during the prenatal stage and mainly by wind erosion in the following evolution, with relatively short stationary phases. This research focused on the determination of endogenic processes of yardangs formation, which would contribute to further understanding of yardangs formation from a geological perspective and promote further study of yardang landform.

  10. Active tectonics of northwestern U.S. inferred from GPS-derived surface velocities

    Energy Technology Data Exchange (ETDEWEB)

    Robert McCaffrey; Robert W. King; Suzette J. Payne; Matthew Lancaster

    2013-02-01

    Surface velocities derived from GPS observations from 1993 to 2011 at several hundred sites across the deforming northwestern United States are used to further elucidate the region's active tectonics. The new velocities reveal that the clockwise rotations, relative to North America, seen in Oregon and western Washington from earlier GPS observations, continue to the east to include the Snake River Plain of Idaho and south into the Basin and Range of northern Nevada. Regional-scale rotation is attributed to gravitationally driven extension in the Basin and Range and Pacific-North America shear transferred through the Walker Lane belt aided by potentially strong pinning below the Idaho Batholith. The large rotating section comprising eastern Oregon displays very low internal deformation rates despite seismological evidence for a thin crust, warm mantle, organized mantle flow, and elevated topography. The observed disparity between mantle and surface kinematics suggests that either little stress acts between them (low basal shear) or that the crust is strong relative to the mantle. The rotation of the Oregon block impinges on Washington across the Yakima fold-thrust belt where shortening occurs in a closing-fan style. Elastic fault locking at the Cascadia subduction zone is reevaluated using the GPS velocities and recently published uplift rates. The 18 year GPS and 80 year leveling data can both be matched with a common locking model suggesting that the locking has been stable over many decades. The rate of strain accumulation is consistent with hundreds of years between great subduction events.

  11. Resistivity and heterogeneity of Earth crust in an active tectonic region, Southern Tuscany (Italy

    Directory of Open Access Journals (Sweden)

    A. Manzella

    2004-06-01

    Full Text Available Southern Tuscany, belonging to the inner zone of the Northern Apennines, Italy, is an ideal laboratory for observing the physical features of the lithosphere and their evolution in tectonically active regions. Here the crust is very thin, with a thickness of less than 25 km, and heat flow is very high, hence only very shallow depths of exploration are needed to investigate many of the middle-deep crustal features that are common to many other parts of the world. The magnetotelluric (MT surveys performed in this region have provided information on the resistivity structure, which is related to the extent and distribution of free fluids and to the partial melts in the crust. The picture emerging from these MT surveys is that of a resistivity structure that is only partly related to the heat flow regime of the area. A very low resistivity was found below the vapour-dominated geothermal system of Larderello and below areas that have no clear connection to any geothermal system, whereas this reduction of resistivity is less conspicuous below the water-dominated geothermal system of Mt. Amiata.

  12. Active tectonics of the Rif Mountains (Morocco) from geomorphic and geochronological data

    Science.gov (United States)

    Ritz, Jean-François; Poujol, Antoine; Tahayt, Abdelilah; Vernant, Philippe; Condomines, Michel; Blard, Pierre-Henri; Braucher, Régis; Benedetti, Lucilla; Bourles, Didier; Leroux-Mallouf, Romain; Ferry, Matthieu; Maate, Soufian

    2014-05-01

    We present results of a geomorphological and morphotectonic analysis of the Rif Mountains (Morocco). We show that the present day kinematics of the Rif is characterized by active deformation along normal and left-lateral strike-slip faults in the North-East (Trougout, Rouadi, Boujibar and Nekor faults), reverse fault in the South (the South Rif Front) and inherited fold structures in the West. Digital Elevation Models of offset drainage features (streams, fluvial terraces) allow determining horizontal cumulative displacements of ~25-35m along the Trougout fault and ~40m along the Nekor fault. 14C dating of tectonic markers yields vertical and horizontal slip rates of ~2.8 mm/yr and ~2.3 mm/yr respectively, along the Trougout fault. For the first time, cosmogenic 3He method is used on volcanic rocks to date the successive exposure of the fault plane. Along the Trougout fault, this yields recurrence time between 3,1 and 4,1 ka. The present-day localized transtension seen in the northeastern Rif morphology (Ras Tarf) is coeval with uplifted marine terraces near the Al Hoceima Bay. U/Th dating of shells yields an average uplift rate of ~0.2 mm/yr during the past 500 Ka. These data show that active transtension in the northeastern Rif is also associated with uplift. Comparison with cosmogenic 10Be/3He dating of perched fluvial surface located above these marine terraces is in progress and may allow us to confirm or not this uplift rate. In the western Rif, geomorphic markers allow us to suggest that active deformation is accommodated along blind thrust and NNW-SSE inherited folds. These new morphotectonic constraints are consistent with the GPS measurements showing southwestward overall motion of most of the Rif belt with respect to stable Africa and suggest a continuum of the deformation from the Pliocene.

  13. Taiwan: a perfect field trip to study active tectonics and erosion processes

    Science.gov (United States)

    Bigot-Cormier, Florence; Beauval, Véronique; Martinez, Claire-Marie; Seyeux, Jana

    2014-05-01

    Taiwan is located at the boundary between the Philippine Sea Plate to the East and the Eurasian Plate to the West. This plate boundary is rather complex since it comprises two subduction zones of reverse polarities. Due to this specific geodynamic context, this field is a perfect area to answer the French program in 5th grade (erosion processes) and 4th grade (active tectonics) in Earth Science class. That's why for the second year, students from the Lycée Français de Shanghai (LFS) in 4th grade will go for a 4-day field trip to discover volcanoes (in the Yangminshan National Park) and para-seismic constructions in the 101 Tower at Taipei. It will remind them the program of their previous class (5ème) through the visit of Yehliu Geographic Park and some other areas in the North of the Island where they will be able to observe different erosion processes (wind or water) carving the landscape. The aim of this field trip is first to show them that Earth Sciences cannot be studied only in class but also on the field to get a better understanding of the processes. In this manner, after having understood the internal thermal system of our Earth in class, they will see its manifestations on the surface of the Earth, by seeing an active explosive volcano with gas ejection, specific mineralization, and hot springs. Furthermore on the field, they will be able to do a link between the external and internal geodynamics processes usually studied separately in middle school. The poster presented will detail the first field trip in Taiwan realized in May 2013 by the LFS 4th grade students and will be made by the students going in June 2014. Thus, this activity will allow them to get a perspective of the topic that they will discover on the field trip.

  14. Seismicity at Uturuncu Volcano, Bolivia: Volcano-Tectonic Earthquake Swarms Triggered by the 2010 Maule, Chile Earthquake and Non-Triggered Background Activity

    Science.gov (United States)

    Christensen, D. H.; Chartrand, Z. A.; Jay, J.; Pritchard, M. E.; West, M. E.; McNutt, S. R.

    2010-12-01

    We find that the 270 ky dormant Uturuncu Volcano in SW Bolivia exhibits relatively high rates of shallow, volcano-tectonic seismicity that is dominated by swarm-like activity. We also document that the 27 February 2010 Mw 8.8 Maule, Chile earthquake triggered an exceptionally high rate of seismicity in the seconds to days following the main event. Although dormant, Uturuncu is currently being studied due to its large-scale deformation rate of 1-2 cm/yr uplift as revealed by InSAR. As part of the NASA-funded Andivolc project to investigate seismicity of volcanoes in the central Andes, a seismic network of 15 stations (9 Mark Products L22 short period and 6 Guralp CMG40T intermediate period sensors) with an average spacing of about 10 km was installed at Uturuncu from April 2009 to April 2010. Volcano-tectonic earthquakes occur at an average rate of about 3-4 per day, and swarms of 5-60 events within a span of minutes to hours occur a few times per month. Most of these earthquakes are located close to the summit at depths near and above sea level. The largest swarm occurred on 28 September 2009 and consisted of 60 locatable events over a time span of 28 hours. The locations of volcano-tectonic earthquakes at Uturuncu are oriented in a NW-SE trend, which matches the dominant orientation of regional faults and suggests a relationship between the fault system at Uturuncu and the regional tectonics of the area; a NW-SE trending fault beneath Uturuncu may serve to localize stresses that are accumulating over the broad area of uplift. Based on automated locations, the maximum local magnitude of these events is approximately M = 4 and the average magnitude is approximately M = 2. An initial estimate of the b-value is about b = 1.2. The Mw 8.8 Maule earthquake on 27 February 2010 triggered hundreds of local volcano-tectonic events at Uturuncu. High-pass filtering of the long period surface waves reveals that the first triggered events occurred with the onset of the Rayleigh

  15. Tectonic Vocabulary & Materialization

    DEFF Research Database (Denmark)

    Hvejsel, Marie Frier; Beim, Anne; Bundgaard, Charlotte

    2015-01-01

    By referring to the fundamental question of how we unite aesthetics and technology – tectonic theory is necessarily a focal point in the development of the architectural discipline. However, a critical reconsideration of the role of tectonic theory seems necessary when facing the present everyday...... architectural practice. In this matter the paper focuses on the need to juxtapose theoretical studies, to bring the present vocabulary of the tectonic further, as well as to spur further practical experiments enabling theory to materialize in the everyday of the current practice....

  16. Architecture and evolution of an Early Permian carbonate complex on a tectonically active island in east-central California

    Science.gov (United States)

    Stevens, Calvin H.; Magginetti, Robert T.; Stone, Paul

    2015-01-01

    The newly named Upland Valley Limestone represents a carbonate complex that developed on and adjacent to a tectonically active island in east-central California during a brief interval of Early Permian (late Artinskian) time. This lithologically unique, relatively thin limestone unit lies within a thick sequence of predominantly siliciclastic rocks and is characterized by its high concentration of crinoidal debris, pronounced lateral changes in thickness and lithofacies, and a largely endemic fusulinid fauna. Most outcrops represent a carbonate platform and debris derived from it and shed downslope, but another group of outcrops represents one or possibly more isolated carbonate buildups that developed offshore from the platform. Tectonic activity in the area occurred before, probably during, and after deposition of this short-lived carbonate complex.

  17. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  18. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  19. Seismic hazard assessment of Syria using seismicity, DEM, slope, active tectonic and GIS

    Science.gov (United States)

    Ahmad, Raed; Adris, Ahmad; Singh, Ramesh

    2016-07-01

    In the present work, we discuss the use of an integrated remote sensing and Geographical Information System (GIS) techniques for evaluation of seismic hazard areas in Syria. The present study is the first time effort to create seismic hazard map with the help of GIS. In the proposed approach, we have used Aster satellite data, digital elevation data (30 m resolution), earthquake data, and active tectonic maps. Many important factors for evaluation of seismic hazard were identified and corresponding thematic data layers (past earthquake epicenters, active faults, digital elevation model, and slope) were generated. A numerical rating scheme has been developed for spatial data analysis using GIS to identify ranking of parameters to be included in the evaluation of seismic hazard. The resulting earthquake potential map delineates the area into different relative susceptibility classes: high, moderate, low and very low. The potential earthquake map was validated by correlating the obtained different classes with the local probability that produced using conventional analysis of observed earthquakes. Using earthquake data of Syria and the peak ground acceleration (PGA) data is introduced to the model to develop final seismic hazard map based on Gutenberg-Richter (a and b values) parameters and using the concepts of local probability and recurrence time. The application of the proposed technique in Syrian region indicates that this method provides good estimate of seismic hazard map compared to those developed from traditional techniques (Deterministic (DSHA) and probabilistic seismic hazard (PSHA). For the first time we have used numerous parameters using remote sensing and GIS in preparation of seismic hazard map which is found to be very realistic.

  20. On active current selection for Lagrangian profilers

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Zhou, Qiuyang; Zielinski, Oliver

    2013-01-01

    simple and computationally-efficient control strategies to actively select and use ocean currents so that a profiler can autonomously reach a desired destination. After briefly presenting a typical profiler and possible mechanical modifications for a coastal environment, we introduce simple mathematical...... models for the profiler and the currents it will use. We then present simple feedback controllers that, using the direction of the currents and taking into account the configuration of the environment (coastal or deep-sea), is able to steer the profiler to any desired horizontal location. To illustrate...... the approach, a few results are presented using both simulated currents and real current velocities from the North Sea....

  1. First results of an INGV project for the integrated analysis of the active tectonics in SW Sicily

    Science.gov (United States)

    Mattia, Mario; Giovanni, Barreca; Carla, Bottari; Valentina, Bruno; Pierfrancesco, Burrato; Fabrizio, Cultrera; Luigi, Dardanelli; Sofia, De Gregorio; Luigi, Ferranti; Laura, Guzzetta; Paolo, Madonia; Carmelo, Monaco; Claudia, Pipitone; Fabrizio, Pepe; Francesco, Guglielmino

    2017-04-01

    We present the first results of a project financed by the "Struttura Terremoti" of INGV to study the potential sources of earthquakes in south-western Sicily, including the area hit by the 1968 Belice earthquake sequence and the archaeological area of Selinunte, affected by two earthquakes in historical times. We adopt in this project a multi-disciplinary approach, with the goal of addressing the following points: 1) define the active tectonic framework of south-western Sicily, 2) investigate and characterize on-shore and off-shore faults, potential sources of damaging earthquakes, and 3) evaluate the current deformation rates. To do this, we collected a new set of geodetic (GPS and InSAR) and geochemical data, and performed geological and geomorphological surveys on-land in the area between Mazara, Castelvetrano and Selinunte. We also acquired high-resolution Sparker seismic profiles off-shore Sciacca. Geological and geomorphological surveys have been focused around the 10 km long Castelvetrano-Campobello di Mazara (CCM) lineament, where previous research (Barreca et al., 2014) showed geodetic and geoarchaeological evidence of recent deformation. In particular, a detailed survey of Quaternary coastal forms and deposits was performed, in order to reconstruct the sequence of uplifted paleoshorelines and to search for differential motions between adjacent coastal sectors spanning the CCM. Preliminary observations indicate that the footwall of the CCM hosts a larger number, and a more elevated position of paleo-shorelines suggestive of syntectonic uplift . A grid of about 200 km of high-resolution reflection seismic profiles was recorded along the continental shelf in the offshore of Sciacca. Profiles are mostly oriented in the WNW-ESE direction, with tie lines acquired in ENE-WSW direction. The acoustic source used during seismic prospecting was a 1 kJ Sparker power supply with a multi-tips Sparker array. Preliminary seismic data interpretation indicates that a

  2. Applicability of dinoflagellate cyst stratigraphy to the analyses of passive and active tectonic settings

    NARCIS (Netherlands)

    Wilpshaar, M.

    1995-01-01

    The notion that fluctuating tectonic stress patterns within or between continental plates directly influence the development of a given sedimentary basin is a well-established concept in geotectonics. In recent years it has become increasingly understood that notably the phase of relative compressio

  3. Applicability of dinoflagellate cyst stratigraphy to the analyses of passive and active tectonic settings

    NARCIS (Netherlands)

    Wilpshaar, M.

    1995-01-01

    The notion that fluctuating tectonic stress patterns within or between continental plates directly influence the development of a given sedimentary basin is a well-established concept in geotectonics. In recent years it has become increasingly understood that notably the phase of relative compressio

  4. Does bipolar pacemaker current activate blood platelets?

    DEFF Research Database (Denmark)

    Gjesdal, Grunde; Hansen, Annebirthe Bo; Brandes, Axel

    2009-01-01

    OBJECTIVE: The aim of this study was to investigate whether bipolar pacemaker current lead can activate blood platelets. The null hypothesis was that 1 minute of electrical stimulation of platelets would not influence their subsequent reactivity to adenosine diphosphate (ADP). BACKGROUND: Both...... platelets and muscle cells contain actin and myosin filaments, and both cells are activated following calcium influx. Muscle cells open their calcium channels and contract when exposed to an electric current. Current through a bipolar pacemaker lead will expose a small volume of blood, including platelets...

  5. Tectonic regimes at the N-Ecuador SW-Colombia active margin from multichannel seismic reflection data

    Science.gov (United States)

    Marcaillou, B.; Collot, J.-Y.; Sage, F.

    2003-04-01

    The North Andean convergent margin displays wide lateral variations in structural and sedimentary characters, which reflect the interaction between large sedimentary input derived from the nearby Andes, inherited structures, and the long-term tectonic deformation resulting from the Nazca plate subduction beneath the South America plate at ~5cm/yr. We use Multichannel Seismic Reflection lines as well as bathymetric data collected during the SISTEUR cruise to construct a tectonic and sedimentary model of the margin between latitudes 0°N and 3.5 °N. The margin shows a prominent re-entrant that is cut transversally by a major crustal fault, i.e. the Manglares Fault (MF). The northern and southern walls of the re-entrant together with the MF divide the margin into four morphostructural segments, with distinct tectonic regimes. The Esmeraldas segment, south of the re-entrant, shows a 100m-deep continental shelf, evidences for mass wasting, and a 10° steep innertrench wall underlain by steeply trenchward dipping horizons, suggesting tectonic erosion. The Manglares segment, located between the southern wall of the re-entrant and the MF, exhibits an up to 3-km-thick trench fill thrust beneath possible narrow frontal thrusts, a wide and largely un-deformed fore-arc basin that is split by a major crustal splay fault. Seaward of the splay fault, the fore-arc basin is tilted trenchward and overlays a thinned margin basement, supporting tectonic erosion. The Tumaco segment, between the MF and the reentrant northern wall, exhibits a 2.5-km-thick trench fill, which underthrusts the margin in the south, and shows clear incipient accretionary thrusts in the north. Splay faults across the margin are unclear, but an uplifted, folded and thrust faulted basement ridge and deformed fore-ar basins indicate active deformation across most of the margin width. The Patia segment, to the north of the re-entrant, shows a highly deformed fore-arc basin and outer ridge fronted by growing 30km

  6. Dinosaur tectonics

    DEFF Research Database (Denmark)

    Graversen, Ole; Milàn, Jesper; B. Loope, David

    2007-01-01

    to crustal scale tectonics associated with plate tectonics and foreland fold-thrust belts. A structural analysis of the dinosaur tracks shows the timing and direction of the forces exercised on the substrate by the animal's foot during the stride. Based on the structural analysis, we establish a scenario...... of the undertrack. The total length of the tectonic disturbance created by the dinosaur is up to three times that of the original footprint. Early, near-surface cementation gave the substrate the rheological properties necessary for development of the observed structures....

  7. GLOBAL WARMING, TECTONIC ACTIVITY AND DESERTISATION%全球变暖、构造运动与沙漠化

    Institute of Scientific and Technical Information of China (English)

    杨学祥

    2001-01-01

    By using the method of statistical and synthetical analysis, the effect of climate warming, tectonic activity, the orbit effect of the earth (and of the moon and planets) and solar activity on precipitatiion is studied. It is pointed out that precipitation relates to tectonic activity, earthquake and climate warming. The orbit effect of the earth is related to drought or excessive rain beause the effect is an improtant factor on the variations of temperature. The orbit effect of the moon and planets and solar activity are also related to drought or exccessive rain. It is the major reasons of desertisation that global temperature is going dawn and tectonic activity gets weaker. Human actions make the desertisation speedily.%采用统计分析与综合分析方法,研究了全球变暖、构造活动、地球(以及月球和行星)轨道效应、太阳活动等对降水的影响。认为构造活动、地震、气候变暖与降水或洪涝灾害有一定关系;地球的轨道效应是地球气候变化的重要因素,从而与旱涝相关;月球行星轨道效应和太阳活动均与旱涝有明显的对应关系。气候变冷和构造活动变弱是沙漠化的主要原因,人类活动则加速了沙漠化的进程。

  8. Active Tectonics and Erosional Unloading at the Eastern Margin of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    Alexander L. Densmore; LI Yong; Michael A. Ellis; ZHOU Rongjun

    2005-01-01

    The eastern margin of the Tibetan Plateau is marked by an extremely steep mountain front with relief of over 5 km. This topography, coupled with abundant Mesozoic thrusts within the margin, explains why tectonic maps of the India-Asia collision typically show the eastern margin as a major thrust zone. Actually, it does not like that. Field observations suggest that the margin is better characterized as a zone of NNE-directed dextral shear with extensive strike-slip faulting and secondary thrusting. The high relief and steep gradients are partially explained by erosional unloading of an elastic lithosphere; the pre-erosion inherited topography may be the inherited Mesozoic thrust belt landscape modified by a component of Cenozoic tectonic shortening.

  9. Everyday Tectonics

    DEFF Research Database (Denmark)

    Beim, Anne; Hvejsel, Marie Frier

    2016-01-01

    to critically juxtapose the two concepts, everyday architecture and tectonics in this paper. We ask ourselves if everyday architecture can be qualified by means of general tectonic considerationsmethod and which strategies are needed to reveal its potential?. To aAnswerring theseese questions entails...... a clarification of concepts. Methodologically we pursue this clarification through a rereading of the essay: “Henri Lefebvre’s essay of 1972 entitled ‘The everyday and everydayness” by Henri Lefebvre (Lefebvre 1972).’ The essay offersing a general definition of the term related to everyday life...... as such and outlinea general definition of the aspects related to everyday life, how it can manifest itself in various cultural practices that can be discussed in relation to ‘everyday architecture’ and tectonic strategies or practices of tectonic methods. As such we propose the notion of ‘the everyday’ as a critical...

  10. Digital Tectonics

    DEFF Research Database (Denmark)

    Christiansen, Karl; Borup, Ruben; Søndergaard, Asbjørn;

    2014-01-01

    Digital Tectonics treats the architectonical possibilities in digital generation of form and production. The publication is the first volume of a series, in which aspects of the strategic focus areas of the Aarhus School of Architecture will be disseminated.......Digital Tectonics treats the architectonical possibilities in digital generation of form and production. The publication is the first volume of a series, in which aspects of the strategic focus areas of the Aarhus School of Architecture will be disseminated....

  11. Late Quaternary tectonics and active ground deformation in the Catania urban area (eastern Sicily): New constraints from a geological investigation

    Science.gov (United States)

    Catalano, Stefano; Pavano, Francesco; Romagnoli, Gino; Tortorici, Giuseppe

    2017-08-01

    New surface and subsurface geological data on the Catania urban area, in eastern Sicily, are here illustrated by a detailed geological map of the city and by four significant cross-sections. Our study aims at defining the prolongation of the principal regional Late Quaternary tectonic features, beneath the city. The resulting geometry of the investigated structures completes the tectonic pictures of two different stages of deformation. The earlier structural association, ranging in age from 600 to 125 ka, consists of a transpressive dextral belt that include E-W oblique thrust ramp, located to the south and the north of the city respectively, connected by a wide NE-SW oriented anticline crossing the urban area. The younger structural association developed since the Late Pleistocene and includes a set of ENE-trending folds that originated at the hangingwall of a main thrust ramp running just beneath the old town (Catania Thrust Ramp). These contractional features have been active during the last 60 ka and their geometry is consistent with the active ground deformation observed by the available geodetic data (GPS vectors and DInSAR analyses). The entire set of the recent structures are bordered to the north by a dextral transfer zone, reactivating part of the previous E-W alignment, that now represents the tectonic boundary with the Mt. Etna Volcano transtensional domain. Our data suggest that the Catania Thrust Ramp could play a main role in the active deformation pattern of the region, thus representing a potential seismotectonic feature to be carefully investigated for the re-evaluation of the seismic hazard of the area.

  12. Late Pleistocene to Historical Activity of the Hovd Fault (Mongolian Altay) from Tectonic Geomorphology and Paleoseismology

    Science.gov (United States)

    Ferry, M. A.; Battogtokh, D.; Ritz, J. F.; Kurtz, R.; Braucher, R.; Klinger, Y.; Ulzibat, M.; Chimed, O.; Demberel, S.

    2015-12-01

    Active tectonics of western Mongolia is dominated by large strike-slip fault systems that produced great historical earthquakes: the Bulnay fault (Mw 8.1 and 8.4 in 1905), the Fu-Yun fault (Mw 8.0 in 1931) and the Bogd fault (Mw 8.1 in 1957). Central to these faults is the Altay Range that accommodates ~4 mm/yr of right-lateral motion. An earthquake of similar magnitude occurred in 1761 and has been attributed to the Hovd fault were seemingly fresh surface rupture was reported in 1985. Here, we study the Ar-Hötöl section of the Hovd fault where surface rupture was described over a length of ~200 km. Detailed mapping of stream gullies from high-resolution Pleiades satellite images show a consistent pattern of right-lateral offsets from a few meters to ~500 m. At Climbing Rock, we surveyed a gully offset by 75 ± 5 m. The associated surface was sampled for 10Be profile which yields an exposure age of 154 ± 20 ka. The resulting minimal right-lateral slip rate ranges 0.4-0.6 mm/yr. However, drainage reconstruction suggests this surface may have recorded as much as 400 ± 20 m of cumulative offset. This implies the Hovd fault may accommodate as much as 2.6 ± 0.4 mm/yr, which would make it the main active fault of the Altay. At a smaller scale, TLS topography documents offsets in the order of 2.5-5 m that likely correspond to the most recent surface-rupturing event with Mw ~8. A value of 2.8-3.0 m is reconstructed from a Uiger grave dated AD 750-840. At Marmot Creek and Small Creek, short drainages flow across the fault and form ponds against the main scarp. Two paleoseimic trenches reveal similar stratigraphy with numerous peat layers that developed over alluvial sands. The fault exhibits near vertical strands affecting pre-ponding units as well as a well-developed peat unit radiocarbon-dated AD 1465-1635. This unit likely corresponds to the ground surface at the time of the last rupture. It is overlain with a sandy pond unit on top of which a second continuous peat

  13. Energy of relief as useful geomorphic index to record seabed tectonic activity: preliminary results from the Sardinia Basin (Tyrrhenian Sea).

    Science.gov (United States)

    Baioni, Davide; Tramontana, Mario

    2017-04-01

    A morphostructural investigation in the seafloor of the Tyrrhenian sea has been carried on using the analysis of the energy of relief (Er). On the dry land the energy of relief is calculated to detect the intensity of denudation processes on the landscape and it is used as useful geomorphic index in the morphotectonic and morphostructural investigations. In fact, when it is calculated for single cells of small size this parameter may reveal zones affected by tectonic movements that control the development of the relief, by measuring unit cells of equal areas and assuming that for such cells mass and gravity acceleration can be treated as constant values. The energy of relief quantitative parameter is thus expressed by the maximum difference in elevation between the highest point and the lowest point measured in a given area. On the sea bottom this geomorphic index has not been well and intensively applied. In fact, the study of this quantitative index was applied only by few authors to the Adriatic seabed; however we believe that because the absent or low erosion of seabed, it can be even more useful and easier to be interpreted as a tectonic activity marker too. Further researches, however, are needed to better understand the sensitivity of this parameter in detecting neo-tectonic features in marine environment. Our research focuses on the calculation and evaluation of energy of relief in the Sardinia Basin, the peri-Tyrrhenian Basin located in the western passive margin of the Tyrrhenian Sea, and bounded offshore to the north by the Baronie Seamounts and to the south by the Ichnusa Seamount. The distribution of the energy of relief was obtained by subdividing the study area into square cells of 25 km2, which were numbered by orthographic coordinates. Highest and lowest elevation for each cell was obtained from the bathymetric map "Tyrrhenian Sea Bathymetry", with 100 m contour lines. Within each cell, the value of the energy of relief was calculated, so obtaining

  14. Spatial variations of current tectonic stress field and its relationship to the structure and rheology of lithosphere around the Bohai Sea, North China

    Science.gov (United States)

    Li, Xianrui; Wang, Jie; Zeng, Zuoxun; Dai, Qingqin

    2017-05-01

    The tectonic stress field in the middle-upper crust is closely related to the structure and rheology of the lithosphere. To determine the stress field in the deep crust, we inversed the focal mechanism solutions (FMSs) of 62 earthquakes that occurred between 2009 and 2015 in the Bohai Sea and its surrounding areas using broadband seismic waveforms collected from 140 stations. We then derived the tectonic stress field using the software SATSI (Spatial And Temporal Stress Inversion) based on the damped linear inversion method. The inversion results show that both the maximum (σ1) and minimum (σ3) principle stress axes throughout the entire region are nearly horizontal except in the Tangshan and Haicheng areas, suggesting that the study area is predominantly under a strike-slip faulting stress regime. The σ1 and σ3 axes are found to be oriented in the NEE-SWW or nearly E-W and NNW-SSE or nearly S-N directions, respectively. These results indicate that the stress field in the North China Craton is controlled by the combined effects of the Pacific Plate westward subduction and the India-Eurasia Plate collision. However, localized normal faulting stress regimes (where the vertical stress σv ≈ σ1) are observed in the Tangshan and Haicheng areas, where low viscosity bodies (LVBs) were identified using geophysical data. Based on the analysis of focal mechanism solutions, active faults and lithosphere rheology characteristics in the Tangshan and Haicheng areas, we speculate that the anomalous stress regime is caused by the local extension resulting from the movement of strike-slip faults under the action of the regional stress field. The existence of LVB may indicate weakness in the crust that favors the accumulation of tectonic stress and triggers large earthquakes.

  15. Multilayer stress from gravity and its tectonic implications in urban active fault zone: A case study in Shenzhen, South China

    Science.gov (United States)

    Xu, Chuang; Wang, Hai-hong; Luo, Zhi-cai; Ning, Jin-sheng; Liu, Hua-liang

    2015-03-01

    It is significant to identify urban active faults for human life and social sustainable development. The ordinary methods to detect active faults, such as geological survey, artificial seismic exploration, and electromagnetic exploration, are not convenient to be carried out in urban area with dense buildings. It is also difficult to supply information about vertical extension of the deeper faults by these methods. Gravity, reflecting the mass distribution of the Earth's interior, provides an alternative way to detect faults, which is more efficient and convenient for urban active fault detection than the aforementioned techniques. Based on the multi-scale decomposition of gravity anomalies, a novel method to invert multilayer horizontal tectonic stresses is proposed. The inverted multilayer stress fields are further used to infer the distribution and stability of the main faults. In order to validate our method, the multilayer stress fields in the Shenzhen fault zone are calculated as a case study. The calculated stress fields show that their distribution is controlled significantly by the strike of the main faults and can be used to derive depths of the faults. The main faults in Shenzhen may range from 4 km to 20 km in the depth. Each layer of the crust is nearly equipressure since the horizontal tectonic stress has small amplitude. It indicates that the main faults in Shenzhen are relatively stable and have no serious impact on planning and construction of the city.

  16. Active Motion of Tectonic Blocks in East Asia: Evidence from GPS Measurement

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The relative Euler vectors of the Pacific, Philippine, Amurian, Okhotsk, N. Honshu and South China plates or blocks are deduced from earthquake slip vectors, transform fault azimuths and spreading rates, which are consistent with new results derived from the International Terrestrial Reference Frame ITRF2000 velocity field, the velocity field of GPS stations in China and the GPS measurement data of the GEONET network in Japan. Based on the two groups of Euler vectors, analysis and comparative study of the relative motions and deformations of the tectonic blocks in East Asia reveal the present-day motion characteristics of the blocks.

  17. Tectonic and Structural Controls of Geothermal Activity in the Great Basin Region, Western USA

    Science.gov (United States)

    Faulds, J. E.; Hinz, N.; Kreemer, C. W.

    2012-12-01

    We are conducting a thorough inventory of structural settings of geothermal systems (>400 total) in the extensional to transtensional Great Basin region of the western USA. Most of the geothermal systems in this region are not related to upper crustal magmatism and thus regional tectonic and local structural controls are the most critical factors controlling the locations of the geothermal activity. A system of NW-striking dextral faults known as the Walker Lane accommodates ~20% of the North American-Pacific plate motion in the western Great Basin and is intimately linked to N- to NNE-striking normal fault systems throughout the region. Overall, geothermal systems are concentrated in areas with the highest strain rates within or proximal to the eastern and western margins of the Great Basin, with the high temperature systems clustering in transtensional areas of highest strain rate in the northwestern Great Basin. Enhanced extension in the northwestern Great Basin probably results from the northwestward termination of the Walker Lane and the concomitant transfer of dextral shear into west-northwest directed extension, thus producing a broad transtensional region. The capacity of geothermal power plants also correlates with strain rates, with the largest (hundreds of megawatts) along the Walker Lane or San Andreas fault system, where strain rates range from 10-100 nanostrain/yr to 1,000 nanostrain/yr, respectively. Lesser systems (tens of megawatts) reside in the Basin and Range (outside the Walker Lane), where local strain rates are typically geothermal fields catalogued, step-overs or relay ramps in normal fault zones serve as the most favorable setting, hosting ~32% of the systems. Such areas have multiple, overlapping fault strands, increased fracture density, and thus enhanced permeability. Other common settings include a) intersections between normal faults and strike-slip or oblique-slip faults (27%), where multiple minor faults connect major structures and

  18. Late Pleistocene and Holocene uplift history of Cyprus: implications for active tectonics along the southern margin of the Anatolian microplate

    Science.gov (United States)

    Harrison, R.W.; Tsiolakis, E.; Stone, B.D.; Lord, A.; McGeehin, J.P.; Mahan, S.A.; Chirico, P.

    2013-01-01

    The nature of the southern margin of the Anatolian microplate during the Neogene is complex, controversial and fundamental in understanding active plate-margin tectonics and natural hazards in the Eastern Mediterranean region. Our investigation provides new insights into the Late Pleistocene uplift history of Cyprus and the Troodos Ophiolite. We provide isotopic (14C) and radiogenic (luminescence) dates of outcropping marine sediments in eastern Cyprus that identify periods of deposition during marine isotope stages (MIS) 3, 4, 5 and 6. Past sea-levels indicated by these deposits are c. 95±25 m higher in elevation than estimates of worldwide eustatic sea-level. An uplift rate of c. 1.8 mm/year and possibly as much as c. 4.1 mm/year in the past c. 26–40 ka is indicated. Holocene marine deposits also occur at elevations higher than those expected for past SL and suggest uplift rates of c. 1.2–2.1 mm/year. MIS-3 marine deposits that crop out in southern and western Cyprus indicate uniform island-wide uplift. We propose a model of tectonic wedging at a plate-bounding restraining bend as a mechanism for Late Pleistocene to Holocene uplift of Cyprus; uplift is accommodated by deformation and seismicity along the margins of the Troodos Ophiolite and re-activation of its low-angle, basal shear zone.

  19. Stability of active mantle upwelling revealed by net characteristics of plate tectonics.

    Science.gov (United States)

    Conrad, Clinton P; Steinberger, Bernhard; Torsvik, Trond H

    2013-06-27

    Viscous convection within the mantle is linked to tectonic plate motions and deforms Earth's surface across wide areas. Such close links between surface geology and deep mantle dynamics presumably operated throughout Earth's history, but are difficult to investigate for past times because the history of mantle flow is poorly known. Here we show that the time dependence of global-scale mantle flow can be deduced from the net behaviour of surface plate motions. In particular, we tracked the geographic locations of net convergence and divergence for harmonic degrees 1 and 2 by computing the dipole and quadrupole moments of plate motions from tectonic reconstructions extended back to the early Mesozoic era. For present-day plate motions, we find dipole convergence in eastern Asia and quadrupole divergence in both central Africa and the central Pacific. These orientations are nearly identical to the dipole and quadrupole orientations of underlying mantle flow, which indicates that these 'net characteristics' of plate motions reveal deeper flow patterns. The positions of quadrupole divergence have not moved significantly during the past 250 million years, which suggests long-term stability of mantle upwelling beneath Africa and the Pacific Ocean. These upwelling locations are positioned above two compositionally and seismologically distinct regions of the lowermost mantle, which may organize global mantle flow as they remain stationary over geologic time.

  20. Channel morphometry, sediment transport, and implications for tectonic activity and surficial ages of Titan basins

    Science.gov (United States)

    Cartwright, Richard; Clayton, Jordan A.; Kirk, Randolph L.

    2011-01-01

    Fluvial features on Titan and drainage basins on Earth are remarkably similar despite differences in gravity and surface composition. We determined network bifurcation (Rb) ratios for five Titan and three terrestrial analog basins. Tectonically-modified Earth basins have Rb values greater than the expected range (3.0–5.0) for dendritic networks; comparisons with Rb values determined for Titanbasins, in conjunction with similarities in network patterns, suggest that portions of Titan's north polar region are modified by tectonic forces. Sufficient elevation data existed to calculate bed slope and potential fluvial sedimenttransport rates in at least one Titanbasin, indicating that 75 mm water ice grains (observed at the Huygens landing site) should be readily entrained given sufficient flow depths of liquid hydrocarbons. Volumetric sedimenttransport estimates suggest that ~6700–10,000 Titan years (~2.0–3.0 x 105 Earth years) are required to erode this basin to its minimum relief (assuming constant 1 m and 1.5 m flows); these lowering rates increase to ~27,000–41,000 Titan years (~8.0–12.0 x 105 Earth years) when flows in the north polar region are restricted to summer months.

  1. Current Activities of the ASME Subgroup NUPACK

    Energy Technology Data Exchange (ETDEWEB)

    Gerald M. Foster; D. Keith Morton; Paul McConnell

    2007-10-01

    Current activities of the American Society of Mechanical Engineers (ASME), Section III Subgroup on Containment Systems for Spent Fuel High-Level Waste Transport Packagings (also known as Subgroup NUPACK) are reviewed with emphasis on the recent revision of Subsection WB. Also, brief insightson new proposals for the development of rules for internal support structures and for a strain-based acceptance criteria are provided.

  2. Thermal basin modelling of the Arauco forearc basin, south central Chile — Heat flow and active margin tectonics

    Science.gov (United States)

    Kuhn, Philipp P.; Echtler, Helmut; Littke, Ralf; Alfaro, Guillermo

    2010-11-01

    The Arauco basin is part of the coastal forearc domain in South-Central Chile. During its evolution since the Late Cretaceous it was subject to multiple deposition cycles and the erosion of lower bathyal to beach and lagoon sediments. These different environments were established in alternating accretional and erosive subduction tectonic settings along the South Andean active margin. Whereas the general development is well understood, inconsistencies arise regarding the origin of the high thermal maturity of Eocene coals and the estimates of vertical movements of the whole area during the Cenozoic. Thermal modelling of this forearc basin provides new insights regarding its thermal evolution and evaluation of the magnitudes of subsidence and inversion. Results are based on the analysis of coal samples from surface outcrops, mines and drill cores of ten onshore wells from ENAP/Sipetrol. Newly derived vitrinite reflectance (VR r) measurements indicated a temperature in the range of 135-150 °C for the oldest sediment unit of the Arauco basin, which was reached in post Eocene times. Furthermore, 1D basin modelling techniques indicate scenarios that could explain the coalification values in the basin's sediments. The models were calibrated against VR r data from drill core samples supplied by ENAP/Sipetrol. A Miocene and an Oligocene subsidence/inversion scenario were considered, while neither could be securely discarded based on the modelling results. Furthermore, it can be shown that the current thermal maturity was not reached by an increased heat flow (HF) or a deep subsidence only. Consequently, a structural inversion accompanied by the erosion of ~ 3.0 ± 0.4 km depending on the locality in combination with a high HF of ~ 64 ± 4 mW/m 2 is the best explanation of the available data. The HF, which is high for a forearc setting, can be attributed to the increased temperature of the relatively young subducted Nazca Plate and an additional influence of ascending hot

  3. The nature of magmatism at Palinpinon geothermal field, Negros Island, Philippines: implications for geothermal activity and regional tectonics

    Science.gov (United States)

    Rae, Andrew J.; Cooke, David R.; Phillips, David; Zaide-Delfin, Maribel

    2004-01-01

    The Palinpinon geothermal field, Negros Island, Philippines is a high-temperature, liquid-dominated geothermal system in an active island-arc volcanic setting. This paper presents a regional context for the Palinpinon geology, discusses the petrogenetic evolution of magmatism in the district and assesses the genetic relationships between intrusion and geothermal circulation. The oldest rock formation, the Lower Puhagan Volcanic Formation (Middle Miocene), is part of a volcanic sequence that is traceable throughout the Visayas region and is related to subduction of the Sulu Sea oceanic basin in a southeasterly direction beneath the Sulu arc. Late Miocene to Early Pliocene times mark a period of regional subsidence and marine sedimentation. A thick sequence of calcareous sediments (Okoy Formation) was deposited during this period. Magmatism in Early Pliocene to Recent times coincided with commencement of subduction at the Negros-Sulu Arc. This produced basaltic andesites and andesites belonging to the Southern Negros and Cuernos Volcanic Formations. During this time the Puhagan dikes and the Nasuji Pluton intruded Middle Miocene, Late Miocene and Early-Late Pliocene formations. Based on radiogenic ( 40Ar/ 39Ar) dating of hornblende, the Puhagan dikes are 4.1-4.2 Ma and the Nasuji Pluton 0.3-0.7 Ma. This age difference confirms these intrusions are not genetically related. The Early Pliocene age of the Puhagan dikes also confirms they are not the heat source for the current geothermal system and that a much younger intrusion is situated beyond drill depths. Igneous rock formations in southern Negros are the products of regional island-arc magmatism with medium K, calc-alkaline, basaltic to dacitic compositions. Their adakitic affinity implies that the melting of subducted oceanic basalt has influenced magmatism in this region. Considering the regional tectonic history the most likely scenarios for the generation of slab melts are: (1) during the Middle Miocene, by the

  4. Volcanic and Tectonic Activity in the Red Sea Region (2004-2013): Insights from Satellite Radar Interferometry and Optical Imagery

    KAUST Repository

    Xu, Wenbin

    2015-04-01

    Studying recent volcanic and tectonic events in the Red Sea region is important for improving our knowledge of the Red Sea plate boundary and for regional geohazard assessments. However, limited information has been available about the past activity due to insufficient in-situ data and remoteness of some of the activity. In this dissertation, I have used satellite remote sensing to derive new information about several recent volcanic and tectonic events in the Red Sea region. I first report on three volcanic eruptions in the southern Red Sea, the 2007-8 Jebel at Tair eruption and the 2011-12 & 2013 Zubair eruptions, which resulted in formation of two new islands. Series of high- resolution optical images were used to map the extent of lava flows and to observe and analyze the growth and destructive processes of the new islands. I used Interferometric Synthetic Aperture Radar (InSAR) data to study the evolution of lava flows, to estimate their volumes, as well as to generate ground displacements maps, which were used to model the dikes that fed the eruptions. I then report on my work of the 2009 Harrat Lunayyir dike intrusion and the 2004 Tabuk earthquake sequence in western Saudi Arabia. I used InSAR observations and stress calculations to study the intruding dike at Harrat Lunayyir, while I combined InSAR data and Bayesian estimation to study the Tabuk earthquake activity. The key findings of the thesis are: 1) The recent volcanic eruptions in the southern Red Sea indicate that the area is magmatically more active than previously acknowledged and that a rifting episode has been taken place in the southern Red Sea; 2) Stress interactions between an ascending dike intrusion and normal faulting on graben-bounding faults above the dike can inhibit vertical propagation of magma towards the surface; 3) InSAR observations can improve locations of shallow earthquakes and fault model uncertainties are useful to associate earthquake activity with mapped faults; 4). The

  5. Formwork tectonics

    DEFF Research Database (Denmark)

    Manelius, Anne-Mette

    2012-01-01

    På engelsk: Based on the concept of techné and framed in architectural studies of tectonics and an experimental practice of making, this paper investigates the multiple technological roles of textiles in fabric formwork for concrete in four analytical studies of experimental data of the author’s ...

  6. Geomorphologic, stratigraphic and sedimentologic evidences of tectonic activity in Sone–Ganga alluvial tract in Middle Ganga Plain, India

    Indian Academy of Sciences (India)

    Sudarsan Sahu; Dipankar Saha

    2014-08-01

    The basement of the Ganga basin in the Himalayan foreland is criss-crossed by several faults, dividing the basin into several sub-blocks forming horsts, grabens, or half-grabens. Tectonic perturbations along basement faults have affected the fluvial regime and extent of sediment fill in different parts of the basin during Late Quaternary. The East Patna Fault (EPF) and the West Patna Fault (WPF), located in Sone–Ganga alluvial tract in the southern marginal parts of Middle Ganga Plain (MGP), have remained tectonically active. The EPF particularly has acted significantly and influenced in evolving the geomorphological landscape and the stratigraphic architecture of the area. The block bounded by the two faults has earlier been considered as a single entity, constituting a half-graben. The present investigation (by morpho-stratigraphic and sedimentologic means) has revealed the existence of yet another fault within the half-graben, referred to as Bishunpur–Khagaul Fault (BKF). Many of the long profile morphological characters (e.g., knick-zone, low width–depth ratio) of the Sone River at its lower reaches can be ascribed to local structural deformation along BKF. These basement faults in MGP lie parallel to each other in NE–SW direction.

  7. A quantitative geomorphological approach to constraining the volcanic and tectonic evolution of the active Dabbahu rift segment, Afar, Ethiopia.

    Science.gov (United States)

    Medynski, Sarah; Pik, Raphaël; Burnard, Peter; Vye-Brown, Charlotte; Blard, Pierre-Henri; France, Lydéric; Dumont, Stéphanie; Grandin, Raphaël; Schimmelpfennig, Irene; Benedetti, Lucilla; Ayalew, Dereje; Yirgu, Gezahegn

    2013-04-01

    In the Afar depression (Ethiopia), extension is organised along rift segments that morphologically resemble oceanic rifts. Segmentation results from interactions between dyke injection and volcanism, as observed during the well-documented 2005 rifting event on the Dabbahu rift segment. This tectono-volcanic crisis was observed in detail via remote sensing techniques, providing invaluable information on the present-day tectonic - magmatic interplay during a sequence of dyke intrusions. However, lack of data remains on timescales of 1 to 100 kyr, the period over which the main morphology of the rift is acquired. The Dabbahu rift segment represents an ideal natural laboratory to study the evolution of rift morphology as a response to volcanic and tectonic influences. We use cosmogenic nuclides (3He and 36Cl) to determine the ages of young (<100 kyr) lava flows and to date the initiation and movement of fault scarps, which cut the lavas. Where possible, we analysed vertical profiles along fault scarps, in an attempt to distinguish individual tectonic events that offset the scarp, estimate their amplitudes and date the recurrence intervals. These geochronological constraints, combined with major & trace element compositions, field mapping and digital mapping (Landsat, ASTER and SPOT imagery), provide valuable insights on the magmatic and tectonic history of the segment. The results show that over the last 100 ka, the northern part of the Dabbahu segment was supplied by at least two different magma reservoirs, which can be identified from their distinctive chemistries. The main reservoir is located beneath Dabbahu volcano at the northern tip of the rift segment, and has been supplied with magma for at least 72 ka. The second reservoir is located further south on the rift axis and corresponds to the current mid-segment magma chamber, which was responsible for the 2005 rifting episode. Two magmatic cycles linked to the Dabbahu magma chamber were recorded, lasting 20-30 kyr

  8. Active tectonics of the Eastern Mediterranean region: deduced from GPS, neotectonic and seismicity data

    Directory of Open Access Journals (Sweden)

    R. Reilinger

    1997-06-01

    Full Text Available This paper reviews the main tectonic features of the Eastern Mediterranean region combining the recent information obtained from GPS measurements, seismicity and neotectonic studies. GPS measurements reveal that the Arabian plate moves northward with respect to Eurasia at a rate of 23 ± 1 mm/yr, 10 mm/yr of this rate is taken up by shortening in the Caucasus. The internal deformation in Eastern Anatolia by conjugate strike-slip faulting and E-W trending thrusts, including the Bitlis frontal thrust, accommodates approximately a 15 mm/yr slip rate. The Northeast Anatolian fault, which extends from the Erzincan basin to Caucasus accommodates about 8 ± 5 mm/yr of left-lateral motion. The neotectonic fault pattern in Eastern Anatolia suggests that the NE Anatolian block moves in an E-ENE direction towards the South Caspian Sea. According to the same data, the Anatolian-Aegean block is undergoing a counter-clockwise rotation. However, from the residuals it appears that this solution can only be taken as a preliminary approximation. The Eulerian rotation pole indicates that slip rate along the North Anatolian fault is about 26 ± 3 mm/yr. This value is 10 mm/yr higher than slip rates obtained from geological data and historical earthquake records and it includes westward drift of the Pontides of a few millimetres/year or more. GPS measurements reveal that the East Anatolian fault accommodates an 11 ± 1 mm/yr relative motion. GPS data suggest that Central Anatolia behaves as a rigid block, but from neotectonic studies, it clearly appears that it is sliced by a number of conjugate strike-slip faults. The Isparta Angle area might be considered a major obstacle for the westward motion of the Anatolian block (Central and Eastern Anatolia. The western flank of this geological structure, the Fethiye-Burdur fault zone appears to be a major boundary with a slip rate of 15-20 mm/yr. The Western Anatolian grabens take up a total of 15 mm/yr NE-SW extension

  9. Task 1 quarternary tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1994-12-31

    Activities on the task of quarternary tectonics for the Yucca Mountain Site investigations are described. Technical topics include: A preliminary reveiw of Bare Mountain Trench; A preliminary detailed lineament map of the Southwestern part of the proposed repository; A discussion on the 1994 Double Spring Flat, Nevada earthquake; and evidence for temporal clustering.

  10. 超大陆旋回与成矿作用%Active Global Tectonics and Ore-Forming Processes

    Institute of Scientific and Technical Information of China (English)

    李文渊

    2012-01-01

    Most of the world's great mineral deposits are the products of a superposition of geological processes which resulted in anomalous concentration of ores, generally occurred at the end of a geological period. Crust-forming processes and the global plate tectonic and mantle plumes paradigm have become indispensable to the broader understanding of how ore deposits form, and a successful exploration of modern ore deposits has been an appreciation of the history and evolution of the continents and oceans. Consequently, the relationship of the formation of ore deposits between global tectonics and the evolution of the continents is a study basement of ore-forming dynamics. In this paper, from the point of view of active global tectonics, and the rates of historic records of amalgamation and dispersal of the super-continents, we study the ore-forming processes in a setting of active global evolution in order to stimulate more further study and reflection of the field.%世界上绝大多数大矿床都是超级地质作用导致矿石异常集中的结果,一般多发生于一个地质作用结束的时期.地壳形成作用和板块构造、地幔柱模型已经成为如何认识矿床形成的关键所在,现代矿床成功的探索实践历史就是对大陆和海洋的深人认识进程.因此,矿床形成与全球构造和大陆的演化关系是研究成矿动力学的基础.本文以全球活动构造的视角,从超大陆聚散的历史纪录角度,对活动的地球演化环境下的成矿作用进行总结探索,以图激发对该领域更为深入的研究和思考.

  11. Alternating Current Influences Anaerobic Electroactive Biofilm Activity.

    Science.gov (United States)

    Wang, Xin; Zhou, Lean; Lu, Lu; Lobo, Fernanda Leite; Li, Nan; Wang, Heming; Park, Jaedo; Ren, Zhiyong Jason

    2016-09-06

    Alternating current (AC) is known to inactivate microbial growth in suspension, but how AC influences anaerobic biofilm activities has not been systematically investigated. Using a Geobacter dominated anaerobic biofilm growing on the electrodes of microbial electrochemical reactors, we found that high frequency AC ranging from 1 MHz to 1 kHz (amplitude of 5 V, 30 min) showed only temporary inhibition to the biofilm activity. However, lower frequency (100 Hz, 1.2 or 5 V) treatment led to 47 ± 19% permanent decrease in limiting current on the same biofilm, which is attributed to the action of electrohydrodynamic force that caused biofilm damage and loss of intercellular electron transfer network. Confocal microscopy images show such inactivation mainly occurred at the interface between the biofilm and the electrode. Reducing the frequency further to 1 Hz led to water electrolysis, which generated gas bubbles that flushed all attached cells out of the electrode. These findings provide new references on understanding and regulating biofilm growth, which has broader implications in biofouling control, anaerobic waste treatment, energy and product recovery, and general understanding of microbial ecology and physiology.

  12. Quantitative data about active tectonics and possible locations of strong earthquakes in the future in the northwestern Beijing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Deterministic, probabilistic and composite-grading methods are used to get the possible locations of strong earth-quakes in the future in Norwest Beijing and its vicinity based on the quantitative data and their accuracy about active tectonics in the research area and by ordering, some questions in the results are also discussed. It shows that the most dangerous fault segments for strong earthquakes in the future include: segments B and A of the southern boundary fault of the Yangyuan basin, the southern boundary fault of the Xuanhua basin, the east segment of the southern Huai¢an fault and the east segment of the northern Yanggao-Tianzhen fault. The most dangerous area is Yangyuan-Shenjing basin, the second one is Tianzhen-Huai¢an-Xuanhua basin and the third dangerous areas are Wanquan-Zhangjiakou and northeast of Yuxian to southwest of Fanshan.

  13. Saturn's Titan: Surface change, ammonia, and implications for atmospheric and tectonic activity

    Science.gov (United States)

    Nelson, R. M.; Kamp, L. W.; Matson, D. L.; Irwin, P. G. J.; Baines, K. H.; Boryta, M. D.; Leader, F. E.; Jaumann, R.; Smythe, W. D.; Sotin, C.; Clark, R. N.; Cruikshank, D. P.; Drossart, P.; Pearl, J. C.; Hapke, B. W.; Lunine, J.; Combes, M.; Bellucci, G.; Bibring, J.-P.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Formisano, V.; Filacchione, G.; Langevin, R. Y.; McCord, T. B.; Mennella, V.; Nicholson, P. D.; Sicardy, B.

    2009-02-01

    Titan is known to have a young surface. Here we present evidence from the Cassini Visual and Infrared Mapping Spectrometer that it is currently geologically active. We report that changes in the near-infrared reflectance of a 73,000 km 2 area on Titan (latitude 26° S, longitude 78° W) occurred between July 2004 and March of 2006. The reflectance of the area increased by a factor of two between July 2004 and March-April 2005; it then returned to the July 2004 level by November 2005. By late December 2005 the reflectance had surged upward again, establishing a new maximum. Thereafter, it trended downward for the next three months. Detailed spectrophotometric analyses suggest these changes happen at or very near the surface. The spectral differences between the region and its surroundings rule out changes in the distribution of the ices of reasonably expected materials such as H 2O, CO 2, and CH 4 as possible causes. Remarkably, the change is spectrally consistent with the deposition and removal of NH 3 frost over a water ice substrate. NH 3 has been proposed as a constituent of Titan's interior and has never been reported on the surface. The detection of NH 3 frost on the surface might possibly be explained by episodic effusive events occur which bring juvenile ammonia from the interior to the surface. If so, its decomposition would feed nitrogen to the atmosphere now and in the future. The lateral extent of the region exceeds that of active areas on the Earth (Hawaii) or Io (Loki).

  14. Post 12 Ma tectonic activity of the Subalpine Molasse resolved by combining thermochronology and critical wedge analysis

    Science.gov (United States)

    von Hagke, C.; Oncken, O.; Ortner, H.; Cederbom, C.

    2012-04-01

    Thermochronological studies in the Northern Alpine Foreland Basin show that the folded and thrusted part of the basin, the Subalpine Molasse (SM), has been tectonically active during the last 12 Ma (Cederbom, C. E. et al., 2011; von Hagke, C. et al., in review). However, the amount of erosion and timing of thrusting is so far only reported from the Swiss Molasse basin. To test whether this is a local signal and whether climate contributed to this thrusting, we report thermochronological data from a profile south of Lake Constance and analyse the results in the framework of critical taper theory. We selected the Bregenzerach stream as suitable study area because it is one of the few profiles, which provides excellent outcrops in all stratigraphic units of the SM and is located east of the Jura fold and thrust belt, north of the Eastern Alps. We present new apatite (U-Th-Sm)/He (AHe) and apatite fission track (AFT) data. In contrast to the Central Alps, the new data do not show full resetting of the AFT system. This demonstrates that the eastern SM has experienced less erosion than the central SM. The AHe system in contrast, shows complete resetting also in the eastern SM. We observe age-offsets across the same thrusts which have been reactivated in the central SM. This confirms that the SM of the Eastern Alps must have been tectonically active until at least 5 Ma, as is also known from the central SM. This implies reactivation of thrusts, which formed originally in mid to late Miocene times. From critical taper analysis, reactivation of thrusting (assuming constant dip of the basal detachment through time) can only be obtained (1) by an increase of basal detachment strength or (2) a decrease of surface slope. An increase of detachment strength through time is either possible due to jumping of the detachment to another stratigraphic level or a change in pore fluid pressure. A decrease in surface slope is either tectonic- or erosion-controlled. We show that today the

  15. Geodetic and tectonic analyses along an active plate boundary: The central Gulf of California

    Science.gov (United States)

    Ortlieb, L.; Ruegg, J. C.; Angelier, J.; Colletta, B.; Kasser, M.; Lesage, P.

    1989-06-01

    The Gulf of California is traversed by the shear plate boundary between Pacific and North American plates and, because of several islands in its central part, offers the possibility of direct geodetic measurements of plate motion. A geodetic network of 150 km aperture, and comprising 11 stations, was measured in 1982 and 1986 by laser trilateration methods. The deformations deduced from the comparison of the two epochs indicate right-lateral shear strain covering the entire gulf rather than localized movements. In the eastern part of the network, between the axial islands and the Sonoran coast, significant right-lateral shear deformation occurs with a relative displacement of about 23 ± 12 cm over 4 years. In the northwestern region (Canal de Ballenas) a right-lateral displacement of about 17 ± 4 cm is observed, whereas in the southwestern part of the network (Canal Sal-si-Puedes), the deformation remains very weak. This suggests that south of the Canal de Ballenas the plate boundary is locked. A tectonic analysis of Neogene and Quaternary faults in Baja California, Sonora, and the central islands of the gulf, permitted the reconstruction of the stress pattern evolution of this area. These data also indicate the predominance of right-lateral motion on a NW-SE trending zone within a regional framework characterized by an approximately N-S compression and an E-W extension. The geodetic results are discussed in comparison with the neotectonic analysis and the seismic data available in the area. The data suggest a broad strain accumulation zone covering the totality of the central Gulf of California. A NW-SE relative velocity of about 8 ± 3 cm/yr is found between the two sides of the gulf during the 1982-1986 interval.

  16. Late Pleistocene to Holocene alluvial tableland formation in an intra-mountainous basin in a tectonically active mountain belt - A case study in the Puli Basin, central Taiwan

    NARCIS (Netherlands)

    Tseng, Chia Han; Lüthgens, Christopher; Tsukamoto, Sumiko; Reimann, Tony; Frechen, Manfred; Böse, Margot

    2016-01-01

    The morphology in Taiwan is a product of high tectonic activity at the convergent margin and East Asian monsoon climate. Tablelands are prominent geomorphic features in the Puli Basin in central Taiwan. These tablelands provide an archive to understand links between past climatic evolution and te

  17. Seismicity study of volcano-tectonic in and around Tangkuban Parahu active volcano in West Java region, Indonesia

    Science.gov (United States)

    Ry, Rexha V.; Priyono, A.; Nugraha, A. D.; Basuki, A.

    2016-05-01

    Tangkuban Parahu is one of the active volcano in Indonesia located about 15 km northern part of Bandung city. The objective of this study is to investigate the seismic activity in the time periods of January 2013 to December 2013. First, we identified seismic events induced by volcano-tectonic activities. These micro-earthquake events were identified as having difference of P-wave and S-wave arrival times less than three seconds. Then, we constrained its location of hypocenter to locate the source of the activities. Hypocenter determination was performed using adaptive simulated annealing method. Using these results, seismic tomographic inversions were conducted to image the three-dimensional velocity structure of Vp, Vs, and the Vp/Vs ratio. In this study, 278 micro-earthquake events have been identified and located. Distribution of hypocenters around Tangkuban Parahu volcano forms an alignment structure and may be related to the stress induced by magma below, also movement of shallow magma below Domas Crater. Our preliminary tomographic inversion results indicate the presences of low Vp, high Vs, and low Vp/Vs ratio that associate to accumulated young volcanic eruption products and hot material zones.

  18. Links among Slope Morphology, Canyon Types and Tectonics on Passive and Active Margins in the Northernmost South China Sea

    Institute of Scientific and Technical Information of China (English)

    Ho-Shing Yu; Emmy T Y Chang

    2009-01-01

    We examine slope profile types and variations in slope gradient and slope relief with depth for both passive and active margins in the northern most South China Sea.The passive South China margin is characterized by an exponential slope profile,mainly assodated with clustered slope-confined canyons.The active Taiwan margin shows a linear-like shape with great variations along the lower slope.Fewer eanyom occur on the Taiwau margin,and hence the influence of canyon incision on slope morphology is relatively less significant.Quantitative analyses of slope curvature,slope gradleut and square root of relief variance are useful statistical parameters to explain characteristics and variability of morphology of the slope of the South China margin,but not for the Kaoping slope on the Talwan side.On the active Taiwan margin,tectonic activities are dominant over sediment deposition and surface erosion,producing a slope profile quite different from those of passive margins of the Middle Atlantic,KwaZulu-Natal,South Africa where failure on slope and accompanying canyon incision are the dominant processes shaping the slope morphology.

  19. Active tectonic deformation of the western Indian plate boundary: A case study from the Chaman Fault System

    Science.gov (United States)

    Crupa, Wanda E.; Khan, Shuhab D.; Huang, Jingqiu; Khan, Abdul S.; Kasi, Aimal

    2017-10-01

    Collision of the Eurasian and Indian plates has resulted in two spatially offset subduction zones, the Makran subduction zone to the south and the Himalayan convergent margin to the north. These zones are linked by a system of left-lateral strike-slip faults known as the Chaman Fault System, ∼1200 km, which spans along western Pakistan. Although this is one of the greatest strike-slip faults, yet temporal and spatial variation in displacement has not been adequately defined along this fault system. This study conducted geomorphic and geodetic investigations along the Chaman Fault in a search for evidence of spatial variations in motion. Four study areas were selected over the span of the Chaman Fault: (1) Tarnak-Rud area over the Tarnak-Rud valley, (2) Spinatizha area over the Spinatizha Mountain Range, (3) Nushki area over the Nushki basin, and (4) Kharan area over the northern tip of the Central Makran Mountains. Remote sensing data allowed for in depth mapping of different components and faults within the Kohjak group. Wind and water gap pairs along with offset rivers were identified using high-resolution imagery and digital-elevation models to show displacement for the four study areas. The mountain-front-sinuosity ratio, valley height-to-width-ratio, and the stream-length-gradient index were calculated and used to determine the relative tectonic activity of each area. These geomorphic indices suggest that the Kharan area is the most active and the Tarnak-Rud area is the least active. GPS data were processed into a stable Indian plate reference frame and analyzed. Fault parallel velocity versus fault normal distance yielded a ∼8-10 mm/yr displacement rate along the Chaman Fault just north of the Spinatizha area. InSAR data were also integrated to assess displacement rates along the fault system. Geodetic data support that ultra-slow earthquakes similar to those that strike along other major strike-slip faults, such as the San Andreas Fault System, are

  20. Spiral tectonics

    Science.gov (United States)

    Hassan Asadiyan, Mohammad

    2014-05-01

    Spiral Tectonics (ST) is a new window to global tectonics introduced as alternative model for Plate Tectonics (PT). ST based upon Dahw(rolling) and Tahw(spreading) dynamics. Analogues to electric and magnetic components in the electromagnetic theory we could consider Dahw and Tahw as components of geodynamics, when one component increases the other decreases and vice versa. They are changed to each other during geological history. D-component represents continental crust and T-component represents oceanic crust. D and T are two arm of spiral-cell. T-arm 180 degree lags behind D-arm so named Retard-arm with respect to D or Forward-arm. It seems primary cell injected several billions years ago from Earth's center therefore the Earth's core was built up first then mantel and finally the crust was build up. Crust building initiate from Arabia (Mecca). As the universe extended gravitation wave swirled the earth fractaly along cycloid path from big to small scale. In global scale (order-0) ST collect continents in one side and abandoned Pacific Ocean in the other side. Recent researches also show two mantels upwelling in opposite side of the Earth: one under Africa (tectonic pose) and the other under Pacific Ocean (tectonic tail). In higher order (order-1) ST build up Africa in one side and S.America in the other side therefore left Atlantic Ocean meandered in between. In order-n e.g. Khoor Musa and Bandar-Deylam bay are seen meandered easterly in the Iranian part but Khoor Abdullah and Kuwait bay meandered westerly in the Arabian part, they are distributed symmetrically with respect to axis of Persian Gulf(PG), these two are fractal components of easterly Caspian-wing and westerly Black Sea-wing which split up from Anatoly. Caspian Sea and Black Sea make two legs of Y-like structure, this shape completely fitted with GPS-velocity map which start from PG and split up in the Catastrophic Point(Anatoly). We could consider PG as remnants of Ancient Ocean which spent up

  1. Ganges-Brahmaputra Delta: Balance of Subsidence, Sea level and Sedimentation in a Tectonically-Active Delta (Invited)

    Science.gov (United States)

    Steckler, M. S.; Goodbred, S. L.; Akhter, S. H.; Seeber, L.; Reitz, M. D.; Paola, C.; Nooner, S. L.; DeWolf, S.; Ferguson, E. K.; Gale, J.; Hossain, S.; Howe, M.; Kim, W.; McHugh, C. M.; Mondal, D. R.; Petter, A. L.; Pickering, J.; Sincavage, R.; Williams, L. A.; Wilson, C.; Zumberge, M. A.

    2013-12-01

    Bangladesh is vulnerable to a host of short and long-term natural hazards - widespread seasonal flooding, river erosion and channel avulsions, permanent land loss from sea level rise, natural groundwater arsenic, recurrent cyclones, landslides and huge earthquakes. These hazards derive from active fluvial processes related to the growth of the delta and the tectonics at the India-Burma-Tibet plate junctions. The Ganges and Brahmaputra rivers drain 3/4 of the Himalayas and carry ~1 GT/y of sediment, 6-8% of the total world flux. In Bangladesh, these two great rivers combine with the Meghna River to form the Ganges-Brahmaputra-Meghna Delta (GBMD). The seasonality of the rivers' water and sediment discharge is a major influence causing widespread flooding during the summer monsoon. The mass of the water is so great that it causes 5-6 cm of seasonal elastic deformation of the delta discerned by our GPS data. Over the longer-term, the rivers are also dynamic. Two centuries ago, the Brahmaputra River avulsed westward up to 100 km and has since captured other rivers. The primary mouth of the Ganges has shifted 100s of km eastward from the Hooghly River over the last 400y, finally joining the Brahmaputra in the 19th century. These avulsions are influenced by the tectonics of the delta. On the east side of Bangladesh, the >16 km thick GBMD is being overridden by the Burma Arc where the attempted subduction of such a thick sediment pile has created a huge accretionary prism. The foldbelt is up to 250-km wide and its front is buried beneath the delta. The main Himalayan thrust front is geologic research in Bangladesh is that the rapid sediment accumulation preserves a detailed structural and stratigraphic archive. We have been tapping into these records using the combination of a local, low-cost drilling method, resistivity imaging and MCS seismics, while GPS, seismology and other geophysical methods are helping to unravel GBMD dynamics. Five transects of >130 wells are

  2. ACTIVITY AND Vp/Vs RATIO OF VOLCANO-TECTONIC SEISMIC SWARM ZONES AT NEVADO DEL RUIZ VOLCANO, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Londoño B. John Makario

    2010-06-01

    Full Text Available An analysis of the seismic activity for volcano-tectonic earthquake (VT swarms zones at Nevado del Ruiz Volcano (NRV was carried out for the interval 1985- 2002, which is the most seismic active period at NRV until now (2010. The swarm-like seismicity of NRV was frequently concentrated in very well defined clusters around the volcano. The seismic swarm zone located at the active crater was the most active during the entire time. The seismic swarm zone located to the west of the volcano suggested some relationship with the volcanic crises. It was active before and after the two eruptions occurred in November 1985 and September 1989. It is believed that this seismic activity may be used as a monitoring tool of volcanic activity. For each seismic swarm zone the Vp/Vs ratio was also calculated by grouping of earthquakes and stations. It was found that each seismic swarm zone had a distinct Vp/Vs ratio with respect to the others, except for the crater and west swarm zones, which had the same value. The average Vp/Vs ratios for the seismic swarm zones located at the active crater and to the west of the volcano are about 6-7% lower than that for the north swarm zone, and about 3% lower than that for the south swarm zone. We suggest that the reduction of the Vp/Vs ratio is due to degassing phenomena inside the central and western earthquake swarm zones, or due to the presence of microcracks inside the volcano. This supposition is in agreement with other studies of geophysics, geochemistry and drilling surveys carried out at NRV.

  3. Everyday Tectonics?

    DEFF Research Database (Denmark)

    Beim, Anne; Hvejsel, Marie Frier

    2016-01-01

    In general architectural practice many of the dwellings and workplaces, where we spend most of our time, are realized under an increasing economical pressure mainly controlled by the regime of the construction industry. The results; what we can call ‘everyday architecture’ may at large be conside......In general architectural practice many of the dwellings and workplaces, where we spend most of our time, are realized under an increasing economical pressure mainly controlled by the regime of the construction industry. The results; what we can call ‘everyday architecture’ may at large...... be considered as ordinary or as 'a-tectonic' made of poor materials, built at a fast pace, and poorly detailed - whereas advanced tectonic reflections are often considered as part of innovative high-end architecture. In general architectural practice many of the dwellings and workplaces, where we spend most...... such as our living spaces and workplaces they tend to be designed as mere rational frameworks rather than enriching spaces for residing. It is our observation that here a spatial utilization of the construction elements and careful detailing is particularly desirable. There is a basic need to change the way...

  4. Why is understanding when Plate Tectonics began important for understanding Earth?

    Science.gov (United States)

    Korenaga, J.

    2015-12-01

    Almost all kinds of geological activities on Earth depend critically on the operation of plate tectonics, but did plate tectonics initiate right after the solidification of a putative magma ocean, or did it start much later, e.g., sometime during the Archean? This problem of the initiation of plate tectonics in the Earth history presents us a unique combination of observational and theoretical challenges. Finding geological evidence for the onset of plate tectonics is difficult because plate tectonics is a dynamic process that continuously destroys a remnant of the past. We therefore need to rely on more secondary traces, the interpretation of which often involves theoretical considerations. At the same time, it is still hard to predict, on a firm theoretical ground, when plate tectonics should have prevailed, because there is no consensus on why plate tectonics currently takes place on Earth. Knowing when plate tectonics began is one thing, and understanding why it did so is another. The initiation of plate tectonics is one of the last frontiers in earth science, which encourages a concerted effort from both geologists and geophysicists to identify key geological evidence and distinguish between competing theories of early Earth evolution. Such an endeavor is essential to arrive at a self-contained theory for the evolution of terrestrial planets.

  5. Interplay between active and past tectonics in the Hellenic Arc (Greece): Geological and geomorphic evidences from Kythira Island

    Science.gov (United States)

    Fernández-Blanco, David; de Gelder, Gino; Delorme, Arthur; Lacassin, Robin; Armijo, Rolando

    2016-04-01

    The Hellenic Arc undergoes the largest convergence velocity and highest seismic activity among Mediterranean subduction systems. The outer-arc high islands of the Hellenic Arc are thus key to understand the mode of deformation of the crust during subduction and the mechanisms behind vertical motions at the front of overriding plates, here and elsewhere. Kythira Island, located between SW Peloponnese and NE Crete, provides an exceptional opportunity to understand the interaction between past and active tectonics in the Hellenic Arc. The recent uplift of the Kythira Island is marked in its landscape as paleosurfaces, marine terraces, abandon valleys and gorges. Together with the sedimentary record of the island and its geologic structures, we attempt to reconstruct its tectonic evolution since the latest Miocene. Here, we present exceptionally detailed geological and geomorphological maps of the Kythira Island based on fieldwork, Pleiades satellite imagery and 2-m resolution DEM, as well as the analyses of marine terraces and river network morphometrics. Pliocene or younger infill sequences rest atop of Palaeocene or older rocks in several marine basins in the island. In the largest marine basin, we found a stratigraphic sequence with a (tilted) continental conglomerate at the base, passing upwards to a disconformal subhorizontal conglomerate, calcarenites and fine sands, and terminating with a marine conglomerate. This marine conglomerate acts as a "cap rock" that marks the topography and shapes the highermost, and most extensive, low-relief surface. Overall, the infill sequence onlaps basement with the exception of the western margin where normal faults partly controlled the deposition of its lower sector. These faults reactivated older Hellenic fold-and-thrust structures, parallel to the subduction trench, and were not active during the maximum marine transgression that led to the deposition of the subhorizontal part of the infill sequence, including the topmost

  6. Flare-Shaped Acoustic Anomalies in the Water Column Along the Ecuadorian Margin: Relationship with Active Tectonics and Gas Hydrates

    Science.gov (United States)

    Michaud, Francois; Proust, Jean-Noël; Dano, Alexandre; Collot, Jean-Yves; Guiyeligou, Grâce Daniella; Hernández Salazar, María José; Ratzov, Gueorgui; Martillo, Carlos; Pouderoux, Hugo; Schenini, Laure; Lebrun, Jean-Frederic; Loayza, Glenda

    2016-10-01

    With hull-mounted multibeam echosounder data, we report for the first time along the active Ecuadorian margin, acoustic signatures of water column fluid emissions and seep-related structures on the seafloor. In total 17 flare-shaped acoustic anomalies were detected from the upper slope (1250 m) to the shelf break (140 m). Nearly half of the flare-shaped acoustic anomalies rise 200-500 m above the seafloor. The base of the flares is generally associated with high-reflectivity backscatter patches contrasting with the neighboring seafloor. We interpret these flares as caused by fluid escape in the water column, most likely gases. High-resolution seismic profiles show that most flares occur close to the surface expression of active faults, deformed areas, slope instabilities or diapiric structures. In two areas tectonic deformation disrupts a Bottom Simulating Reflector (BSR), suggesting that buried frozen gas hydrates are destabilized, thus supplying free gas emissions and related flares. This discovery is important as it opens the way to determine the nature and origin of the emitted fluids and their potential link with the hydrocarbon system of the forearc basins along the Ecuadorian margin.

  7. Continental tectonics in the aftermath of plate tectonics

    Science.gov (United States)

    Molnar, Peter

    1988-01-01

    It is shown that the basic tenet of plate tectonics, rigid-body movements of large plates of lithosphere, fails to apply to continental interiors. There, buoyant continental crust can detach from the underlying mantle to form mountain ranges and broad zones of diffuse tectonic activity. The role of crustal blocks and of the detachment of crustal fragments in this process is discussed. Future areas of investigation are addressed.

  8. Continental tectonics in the aftermath of plate tectonics

    Science.gov (United States)

    Molnar, Peter

    1988-01-01

    It is shown that the basic tenet of plate tectonics, rigid-body movements of large plates of lithosphere, fails to apply to continental interiors. There, buoyant continental crust can detach from the underlying mantle to form mountain ranges and broad zones of diffuse tectonic activity. The role of crustal blocks and of the detachment of crustal fragments in this process is discussed. Future areas of investigation are addressed.

  9. Hot spot activity and tectonic settings near Amsterdam–St. Paul plateau (Indian Ocean)

    Digital Repository Service at National Institute of Oceanography (India)

    Janin, M.; Hemond, C.; Guillou, H.; Maia, M.; Johnson, K.T.M.; Bollinger, C.; Liorzou, C.; Mudholkar, A.V.

    ages for all the seamounts. We can also exclude systematic datings of late-stage activity occurring several My after the main construction of the edifices. Indeed, Vergara Lopes [2009] performed a magnetic modeling... hotspot intraplate activity as well. This statement supports the assumption of a possible emerged stage for both of them since they are old enough to have grown above sealevel and being eroded subsequently. Conversely, a...

  10. Tectonically driven fluid flow and gold mineralisation in active collisional orogenic belts: comparison between New Zealand and western Himalaya

    Science.gov (United States)

    Craw, D.; Koons, P. O.; Horton, T.; Chamberlain, C. P.

    2002-04-01

    Hydrothermal activity and mesothermal-styled gold mineralisation occurs near the main topographic divide of most active or young collisional mountain belts. The Southern Alps of New Zealand is used in this study as a model for the mineralising processes. The collisional tectonics results in a two-sided wedge-shaped orogen into which rock is transported horizontally. Upper crustal rocks pass through the orogen and leave the orogen by erosion, whereas lower crustal rocks are deformed into the mountain roots. High relief drives meteoric water flow to near the brittle-ductile transition. Lower to upper greenschist facies metamorphic reactions, driven by deformation at the crustal decollement and in the root, release water-rich fluids that rise through the orogen. Intimate chemical interaction between fluid and rock results in dissolution and later precipitation of gold, arsenic and sulphur. Fluid flow and mineralisation in the topographic divide region is facilitated by a network of steeply dipping faults and associated rock damage zones where oblique strike-slip faults intersect the thrust faults that strike subparallel to the main mountain range. The Nanga Parbat massif of the western Himalaya is an example of an active collisional zone which hosts hydrothermal activity but no gold mineralisation. The lack of gold mineralisation is due to the following factors: CO 2-dominated rising metamorphic fluid in dehydrated amphibolite-granulite facies metamorphic rocks does not dissolve gold and arsenic; hot (up to 400 °C) meteoric water confined to fractures in the gneiss limits dissolution of gold and arsenic; low density of hot water/dry steam, and low reduced sulphur content of fluid, restrict solubility of gold and arsenic; absence of fracture networks in the core of the massif and the small volumes of circulating fluid limit metal concentration; and lack of reactive rock compositions limits chemically mediated metal deposition.

  11. A systematic overview of the coincidences of river sinuosity changes and tectonically active structures in the Pannonian Basin

    Science.gov (United States)

    Petrovszki, Judit; Székely, Balázs; Timár, Gábor

    2012-12-01

    As tectonic movements change the valley slope (low-gradient reaches of valleys, in sedimentary basins), the alluvial rivers, as sensitive indicators, respond to these changes, by varying their courses to accommodate this forcing. In our study sinuosity values, a commonly used characteristic parameter to detect river pattern changes, were studied for the major rivers in the Pannonian Basin in order to reveal neotectonic influence on their planform shape. Our study area comprises the entire Pannonian Basin (330,000 km2) located in eastern Central-Europe, bounded by the Alps, Carpathians and Dinarides. The studied rivers were mostly in their natural meandering state before the main river regulations of the 19th century. The last quasi-natural, non-regulated river planforms were surveyed somewhat earlier, during the Second Military Survey of the Habsburg Empire. Using the digitized river sections of that survey, the sinuosities of the rivers were calculated with different sample section sizes ranging from 5 km to 80 km. Depending on the bank-full discharge, also a 'most representative' section size is given, which can be connected to the neotectonic activity. In total, the meandering reaches of 28 rivers were studied; their combined length is 7406 km. The places where the river sinuosity changed were compared to the structural lines of the "Atlas of the present-day geodynamics of the Pannonian Basin" (Horváth et al., 2006). 36 junctions along 26 structural lines were identified where the fault lines of this neotectonic map crossed the rivers. Across these points the mean sinuosity changed. Depending on the direction of the relative vertical movements, the sinuosity values increased or decreased. There were some points, where the sinuosity changed in an opposite way. Along these sections, the rivers belong to the range of unorganized meandering or there are lithological margins. Assuming that the rivers indicate on-going faulting accurately, some places were found

  12. A subdued topography among the high relief, tectonic-active island ---registered middle to late Pleistocene climatic changes in Taiwan

    Science.gov (United States)

    Liew, P.; Chen, B.

    2003-12-01

    The island of Taiwan is geographically in the frontal zone of the Asian monsoon region, and is geologically located in the collision boundary between the Philippine Sea plate and the Eurasian plate. A Holocene uplifting rate of up to 10mm/yr in the eastern coast has been documented in this high relief mountainous island, and active folds and thrusts are common. When tracing the rivers backward to the mountain, one often encounters a subdued topography, covered by primary lateritic soil, above the higher river terrace and below the rugged mountains, and is referred to as lateritic highland (LH) by a previous author. Studies in paleoclimatology and geomorphology enable us to refine the possible age and origin of this remarkable topography. The penultimate glacial-interglacial cycle and the last interglacial period should be the major interval for the development of lateritic highland. LH may be looked upon as a reference surface for studying the dynamic evolution of the tectonic landscape of Taiwan. It shows that the lower uplifting rate is the most important factor for the preservation of the LH topography in this island. Based on the morphology of LH, different deformation styles are recognized in north and south Chiayi (near tropic of cancer), in western Taiwan. To the north, platforms originating from piedmont LH are well developed, whereas to the south, platforms and piedmont LH are hardly visible. This contrast is probably due to a lithological variance between them.

  13. Damping scaling factors for elastic response spectra for shallow crustal earthquakes in active tectonic regions: "average" horizontal component

    Science.gov (United States)

    Rezaeian, Sanaz; Bozorgnia, Yousef; Idriss, I.M.; Abrahamson, Norman; Campbell, Kenneth; Silva, Walter

    2014-01-01

    Ground motion prediction equations (GMPEs) for elastic response spectra are typically developed at a 5% viscous damping ratio. In reality, however, structural and nonstructural systems can have other damping ratios. This paper develops a new model for a damping scaling factor (DSF) that can be used to adjust the 5% damped spectral ordinates predicted by a GMPE for damping ratios between 0.5% to 30%. The model is developed based on empirical data from worldwide shallow crustal earthquakes in active tectonic regions. Dependencies of the DSF on potential predictor variables, such as the damping ratio, spectral period, ground motion duration, moment magnitude, source-to-site distance, and site conditions, are examined. The strong influence of duration is captured by the inclusion of both magnitude and distance in the DSF model. Site conditions show weak influence on the DSF. The proposed damping scaling model provides functional forms for the median and logarithmic standard deviation of DSF, and is developed for both RotD50 and GMRotI50 horizontal components. A follow-up paper develops a DSF model for vertical ground motion.

  14. Dynamical Stress Analysis of Tectonic Earthquakes in Nusa Tenggara and its possible relations to the Activity of Mt. Rinjani, Indonesia

    Directory of Open Access Journals (Sweden)

    Bakti Sukrisna

    2017-01-01

    Full Text Available Some strong earthquakes are associated with increasing of volcanic activity in near and also in far field. This research is to investigate the effect of the tectonic earthquakes in Nusa Tenggara Island area towards the October 25th,2015 eruption of Mt. Rinjani, Indonesia. Three earthquakes occurred before the eruptions; Mw 5 Sumba earthquake on June 10th 2015, Mw 5.8 South of Java earthaquake July 26th, 2016 and Mw 5 South of Bali on August 6th, 2015. In theory, dynamical stress transfer can be calculated by analyzing synthetic seismogram as a waveform simulation at the volcano and the change of dynamical stress can be calculated with the finitedifference numerical method. Our result indicates that the dynamic stress value is still below the threshold value that can trigger eruptions. Simulation of three earthquakes by varying the magnitude of each earthquake shows that dynamic stress changes will surpass the threshold at Mw  7.5. As all the earthquake that used in this study have magnitude smaller then the threshold, it can be concluded that the eruption of Mount Rinjani was triggered by internal factors, and very unlikely triggered by tyhe earthquake we investigated in this study.

  15. On Active Current Selection for Lagrangian Profilers

    Directory of Open Access Journals (Sweden)

    J. Jouffroy

    2013-01-01

    Full Text Available Autonomous Lagrangian profilers are now widely used as measurement and monitoring platforms, notably in observation programs as Argo. In a typical mode of operation, the profilers drift passively at their parking depthbefore making a vertical profile to go back to the surface. This paperpresents simple and computationally-efficient control strategies to activelyselect and use ocean currents so that a profiler can autonomously reach adesired destination. After briefly presenting a typical profiler andpossible mechanical modifications for a coastal environment, we introducesimple mathematical models for the profiler and the currents it will use. Wethen present simple feedback controllers that, using the direction of thecurrents and taking into account the configuration of the environment(coastal or deep-sea, is able to steer the profiler to any desiredhorizontal location. To illustrate the approach, a few results are presentedusing both simulated currents and real current velocity profiles from theNorth Sea.

  16. Overview of Current Activities in Combustion Instability

    Science.gov (United States)

    2015-10-02

    9/23/2015 14. ABSTRACT Briefing Charts/Viewgraph 15. SUBJECT TERMS N/A 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...CSTD Approved for public release; distribution unlimited 14 ALREST phase II Multifidelity Tools and Methodologies Phase I VISP SPACE Current gen  HF ...Current gen  HF ,  productional Next gen  HF F i d e l i t y High fidelity Cost  ALREST phase II Experiments  Approved for public release

  17. Bathymetric characterization of tectonically active basins in the northern Gulf of California

    Science.gov (United States)

    Prol-Ledesma, R. M.; Canet, C.; Dando, P. R.

    2009-04-01

    The Wagner Basin can be considered a "nascent spreading centre" that evolved from a half graben with a thick sediment cover that may mask magmatic activity at depth. The 200-210 m deep Wagner and Consag Basins are the northernmost of the 8 active extensional basins within the Gulf of California rift system and have been assumed to be mostly hydrothermally inactive; however, bathymetric data show dense deep faulting, mainly on the SE edge of the basins; additionally, the presence of extensive gas venting and heated sediments along the Wagner Fault was observed. Detailed bathymetry of the Wagner and Consag Basins shows the steep eastern edge of the basins bordered by the Wagner Fault. Bathymetry and profiler data revealed large vertical displacements due to faulting that disrupted the sedimentary column. More than 246 bubble plumes were mapped on the echo-sounder profiles, many rising to the surface from 65 -150 m depth and the area affected by low bottom pH, due to CO2 discharge, was in excess of 365 km2. Bubbles were observed breaking the sea surface from some large plumes. Only a minority of the vents present were mapped with the echo-sounders, since the closest survey lines were 1km apart. Based on the bottom coverage of the acoustic beam we estimate that there are at least 15,000 individual gas vents along the Wagner fault. Profiler images showed gas channels and chimneys associated with sedimentary layers. The gas plumes originated from sites of intense disruptions of the upper sediments (synsedimentary faults, pockmarks, mud domes and diapirs and raised irregular hard reflectors). Beneath the plumes, there were enhanced sedimentary reflectors and acoustic blanking indicative of subsurface gas accumulation. One of the strongest vents was associated with a mud diapir. Cemented sediments were common inside pockmarks and around gas outlets; 13 (22%) of grab and box core samples in the outgassing area contained these but in many cases the grab was empty after

  18. Regional Tectonic Framework and Human Activities on the North Central Part of The Mexican Volcanic Belt.

    Science.gov (United States)

    Nieto-Obregon, J.

    2001-12-01

    Faults and fractures northeasterly oriented dipping NW and SE, with slips mainly normal with a slight left lateral component, affect a suite of rocks of Mesozoic to Pleistocene age, in the area of El Bajio, in the states of Queretaro, Guanajuato, Michoacan, and Aguascalientes. The faults and fractures have affected the infrastructure of the cities and surroundings of Queretaro, Celaya, Salamanca, Irapuato, Silao, Leon and Aguascalientes. In the city of Queretaro, the Tlacote-Balvanera active fault has developed a scarp and its motion may potentially affect life lines of great importance. In Celaya City a N-S trending fault traverses the city and has produced a step wise scarp more than 1.80 m high, damaging houses, streets and life lines. In Salamanca, a fault trending N 60oE, dipping to the SE extends from Cerro Gordo to the SW traversing the city and affecting with a varying degree its infrastructure. Displacements observed within the urban area reach as much as 50 cm. Close to Irapuato City, in a quarry near La Valencianita village, a N 45oE trending fault dipping to the NW affects a lacustrine sequence bearing calcareous horizons. The fault exhibits a throw of 10 m and passes north of the urban area. A similarly oriented fault traverses the city of Irapuato, and near the Traffic Circle of Puente de Guadalupe, changes its strike to the SE and continues to the city limits. In the city of Silao, a fault oriented N 60oE, traverses the city and continues to the SW up to the localities of Venta de Ramales and La Aldea. Important displacements in urban and rural areas reach more than 60 cm. Outside the city of Leon in the junction of the highways to Aguascalientes and Guadalajara a normal fault plane NE oriented and dipping SE shows striations compatible with a normal left lateral motion. Faulting is associated with old buried scarps controlled by pre existing faults, and over exploited aquifers. Some of these faults however are considered potentially active based on

  19. Surface Rupture of the 2005 Kashmir, Pakistan, Earthquake and its Active Tectonic Implications

    Science.gov (United States)

    Kaneda, H.; Nakata, T.; Tsutsumi, H.; Kondo, H.; Sugito, N.; Awata, Y.; Akhtar, S. S.; Majid, A.; Khattak, W.; Awan, A. A.; Yeats, R. S.

    2006-12-01

    The 8th October 2005 Kashmir earthquake of Mw 7.6 struck the westernmost area of the Indian-Eurasian collision zone, resulting in the worst earthquake disaster ever recorded along the frontal Himalaya. Although none of the historical Himalayan earthquakes is reported to have produced primary surface rupture, our field mapping reveals that the 2005 earthquake accompanied a NW-trending ~70-km-long distinctive surface rupture with maximum and mean vertical separations of ~7 m and ~3 m, respectively. Typical surface expression of faulting is a NE-side-up fault scarp or warp with surface shortening features at its base and tension cracks on its crest. Bulging and back-tilting are also observed on the upthrown side at many places. The surface rupture is subdivided into three geometrical segments separated by small steps. Location of the hypocenter suggests that the rupture was initiated at a deep portion of the northern-central segment boundary and bilaterally propagated to eventually break three segments. Mapped surface rupture trace clearly shows that neither the Himalayan Frontal Thrust (HFT) nor the Main Boundary Thrust (MBT) is responsible for the earthquake, but a geomorphologically-evident active fault within the Sub-Himalaya, the Balakot-Garhi fault, is a causative fault, although a part of the Balakot-Garhi fault appears to coincide with the surface trace of the MBT. Cumulative vertical separation of the most extensively recognized fluvial terrace surface is 7-8 times larger than the 2005 separation, implying occurrence of 7-8 similar earthquakes after the surface abandonment. If this deeply-incised fill surface is related to sediment yield increase due to the last major glaciation around 20 ka, the rupture interval and vertical slip rate of the Balakot-Garhi fault are estimated to be on the order of ~3000 years and ~1 mm/yr, respectively. By using the seismologically determined fault dip of ~30 degrees, horizontal shortening rate across the fault is then

  20. Permian to late Cenozoic evolution of northern Patagonia: Main tectonic events, magmatic activity, and depositional trends

    Science.gov (United States)

    Uliana, M. A.; Biddle, K. T.

    The late Paleozoic to late Cenozoic evolution of northern Patagonia was influenced significantly by events that occurred while the area was part of the South American sector of Gondwanaland. Late Paleozoic to Middle Triassic subduction along the edge of the supercontinent formed a broad convergent-margin system that is the underpinning of northern Patagonia. Deformation (Gondwanidian orogeny) associated with the subduction is recognized in both the forearc and the convergent backarc areas. Regional extension, accompanied by bimodal volcanism, began in the Late Triassic and led to the formation of a number of north-northwest trending rift basins in Patagonia, which generally followed the Gondwanidian basement grain. Continued extension in the Jurassic and Early Cretaceous led to the opening of the Rocas Verdes marginal basin in southern Chile and, ultimately, to the opening of the South Atlantic Ocean. Once oceanic crust began to form, faulting and volcanism declined in Patagonia. During the late Early Cretaceous to the Late Cretaceous, sags over the rift basins coalesced to form a broad backarc basin behind the volcanic arc to the west. These sags are suggestive of thermally driven subsidence. Subsidence of the evolving Atlantic margin allowed extensive marine transgressions to take place from the east. The stratigraphic record of northern Patagonia reflects these events. The upper Paleozoic to upper Mesozoic sedimentary sequences were deposited in basins directly associated with convergent activity along the margin of Gondwanaland or in rift basins created during its breakup. Even though the Tertiary evolution of Patagonia was dominated by events along the western margin of South America, the patterns of sediment transport, thickness, and general shoreline position were still influenced by the locations of the Mesozoic rifts formed during the breakup of Gondwanaland.

  1. Active tectonics and rheology of slow-moving thrusts in the Tibetan foreland of peninsular India

    Science.gov (United States)

    Copley, Alex; Mitra, Supriyo; Sloan, Alastair; Gaonkar, Sharad; Avouac, Jean-Philippe; Hollingsworth, James

    2016-04-01

    Peninsular India is cut by active thrust faults that break in earthquakes in response to the compressive force exerted between India and the Tibetan Plateau. The rate of deformation is low, with 2 +/- 1 mm/yr of shortening being accommodated over the entire N-S extent of the Indian sub-continent. However, the large seismogenic thickness in the region (40-50 km), and the long faults, mean that the rare earthquakes that do occur can have magnitudes up to at least 8. This contribution describes studies of two large Indian earthquakes, and their rheological and hazard implications, using a range of techniques. First, the Mw 7.6 Bhuj (Gujarat) earthquake of 2001 is examined using a combination of seismology, InSAR, and levelling data. A slip model for the earthquake will be presented, which allows the material properties of the fault plane to be examined. Second, a Holocene-age earthquake rupture from central India will be discussed. Geomorphic analysis of the scarps produced by the event suggest a magnitude of 7.6 - 8.4. Both of these earthquakes had unusually large stress-drops, amongst the largest recorded for shallow earthquakes. The information provided by these two events will be combined with calculations for the total compressive force being transmitted through the Indian peninsular in order to suggest that the faults are characterised by a low coefficient of friction (approximately 0.1), and that the stress-drops in the earthquakes are close to complete. In turn, these results imply that the majority of the force being transmitted through the Indian plate is supported by the brittle crust. Finally, the along-strike continuation of the faults will be described, with implications for hazard assessment and material properties throughout India.

  2. Evidence of active tectonics on a Roman aqueduct system (II-III century A.D.) near Rome, Italy

    Science.gov (United States)

    Marra, Fabrizio; Montone, Paola; Pirro, Mario; Boschi, Enzo

    2004-04-01

    In this paper we describe evidence of strong tectonic deformation affecting two aqueducts of Roman age (II-III century A.D.). The channels are located approximately 20 km northeast of Rome along the ancient Via Tiburtina. Brittle and ductile deformation affects these two structures, including extensional joint systems, NE-oriented faults, and horizontal distortion. This deformation is consistent with right-lateral movement on major N-striking faults, and represents the first evidence that tectonic deformation took place in historical times in the vicinity of Rome, with local strike-slip movement superimposed on a regional extensional fault system.

  3. Soils and geomorphic evolution of bedrock facets on a tectonically active mountain front, western Sangre de Cristo Mountains, New Mexico

    Science.gov (United States)

    Menges, Christopher M.

    1990-09-01

    Soil profiles, colluvial stratigraphy, and detailed hillslope morphology are key elements used for geomorphic interpretations of the form and long-term evolution of triangular facets on a 1200 m high, tectonically active mountain front. The facets are developed on Precambrian gneisses and Tertiary volcanic and plutonic rocks along a complexly segmented, active normal-fault zone in the Rio Grande rift of northern New Mexico. The detailed morphologies of 20- to 350 m high facets are defined by statistical and time-series analyses of 40 field transects that were keyed to observations of colluvium, bedrock, microtopography, and vegetation. The undissected parts of most facets are transport-limited hillslopes mantled with varying thicknesses (0.1 to > 1 m thick) of sand and gravel colluvium between generally sparse (≤10-30%) bedrock outcrops. Facet soils range from (a) thin (≤ 0.2 m) weakly developed soils with cumulic silty A or transitional A/B epipedons above Cox horizons in bedrock or colluvium, to (b) deep (≥0.5-1 m) moderately to strongly developed profiles containing thick cambic (Bw) and/or argillic (Bt) horizons that commonly extend into highly weathered saprolitic bedrock. The presence of strongly weathered profiles and thick colluvium suggests that rates of colluvial transport and hillslope erosion are less than or equal to rates of soil development over at least a large part of the Holocene. The catenary variation of soils and colluvium on selected facet transects indicate that the degree of soil development generally increases and the thickness of colluvium decreases upslope on most facets. This overall pattern is commonly disrupted on large facet hillslopes by irregular secondary soil variations linked to intermediate-scale (20-60 + m long) concave slope elements. These features are interpreted to reflect discontinuous transport and erosion of colluvium down-slope below bedrock outcrops. The degree of weathering in subsurface bedrock commonly

  4. Active tectonics, paleoseismology and associated methodological challenges posed by the slow moving Alhama de Murcia fault (SE Iberia)

    Science.gov (United States)

    Ferrater, Marta; Ortuño, Maria; Masana, Eulàlia; Pallàs, Raimon; Perea, Hector; Baize, Stephane; García-Meléndez, Eduardo; Martínez-Díaz, José J.; Echeverria, Anna; Rockwell, Thomas; Sharp, Warren D.; Arrowsmith, Ramon; Medialdea, Alicia; Rhodes, Edward

    2016-04-01

    The Alhama de Murcia fault (AMF) is a 87 km-long left-lateral slow moving fault and is responsible for the 5.1 Mw 2011 Lorca earthquake. The characterization of the seismic potential of seismogenic strike-slip slow moving faults is necessary but raises huge methodological challenges, as most paleoseismological and active tectonic techniques have been designed on and for fast moving faults. The AMF is used here as a pilot study area to adapt the traditional geomorphological and trenching analyses, especially concerning the precise quantification of offset channels. We: 1) adapted methodologies to slow moving faults, 2) obtained, for the first time, the slip rate of the AMF, and 3) updated its recurrence period and maximum expected magnitude. Morphotectonic studies aim to use the measured tectonic offset of surface channels to calculate seismic parameters. However, these studies lack a standard criterion to score the analysed features. We improved this by differentiating between subjective and objective qualities, and determining up to three objective parameters (lithological changes, associated morphotectonics and shape, and three shape sub-parameters; all ranging from 0 to 1). By applying this methodology to the AMF, we identified and characterized 138 offset features that we mapped on a high-resolution (0.5 × 0.5 m pixel size) Digital Elevation Model (DEM) from a point cloud acquired in 2013 by airborne light detection and ranging (lidar). The identified offsets, together with the ongoing datings, are going to be used to calculate the lateral slip rate of the AMF. In three-dimensional trenches, we measured the offsets of a buried channel by projecting the far-field tendency of the channel onto the fault. This procedure is inspired by the widespread geomorphological procedure and aims to avoid the diffuse deformation in the fault zone associated with slow moving faults. The calculation of the 3D tendency of the channel and its projection onto the fault permitted

  5. Edaphics, active tectonics and animal movements in the Kenyan Rift - implications for early human evolution and dispersal

    Science.gov (United States)

    Kübler, Simon; Owenga, Peter; Rucina, Stephen; King, Geoffrey C. P.

    2014-05-01

    The quality of soils (edaphics) and the associated vegetation strongly controls the health of grazing animals. Until now, this has hardly been appreciated by paleo-anthropologists who only take into account the availability of water and vegetation in landscape reconstruction attempts. A lack of understanding the importance of the edaphics of a region greatly limits interpretations of the relation between our ancestors and animals over the last few million years. If a region lacks vital trace elements then wild grazing and browsing animals will avoid it and go to considerable length and take major risks to seek out better pasture. As a consequence animals must move around the landscape at different times of the year. In complex landscapes, such as tectonically active rifts, hominins can use advanced group behaviour to gain strategic advantage for hunting. Our study in the southern Kenya rift in the Lake Magadi region shows that the edaphics and active rift structures play a key role in present day animal movements as well as the for the location of an early hominin site at Mt. Olorgesailie. We carried out field analysis based on studying the relationship between the geology and soil development as well as the tectonic geomorphology to identify 'good' and 'bad' regions both in terms of edaphics and accessibility for grazing animals. We further sampled different soils that developed on the volcanic bedrock and sediment sources of the region and interviewed the local Maasai shepherds to learn about present-day good and bad grazing sites. At the Olorgesailie site the rift valley floor is covered with flood trachytes; basalts only occur at Mt. Olorgesailie and farther east up the rift flank. The hominin site is located in lacustrine sediments at the southern edge of a playa that extends north and northwest of Mt. Olorgesailie. The lakebeds are now tilted and eroded by motion on two north-south striking faults. The lake was trapped by basalt flows from Mt. Olorgesailie

  6. Repeated large-magnitude earthquakes in a tectonically active, low-strain continental interior: The northern Tien Shan, Kyrgyzstan

    Science.gov (United States)

    Landgraf, A.; Dzhumabaeva, A.; Abdrakhmatov, K. E.; Strecker, M. R.; Macaulay, E. A.; Arrowsmith, Jr.; Sudhaus, H.; Preusser, F.; Rugel, G.; Merchel, S.

    2016-05-01

    The northern Tien Shan of Kyrgyzstan and Kazakhstan has been affected by a series of major earthquakes in the late 19th and early 20th centuries. To assess the significance of such a pulse of strain release in a continental interior, it is important to analyze and quantify strain release over multiple time scales. We have undertaken paleoseismological investigations at two geomorphically distinct sites (Panfilovkoe and Rot Front) near the Kyrgyz capital Bishkek. Although located near the historic epicenters, both sites were not affected by these earthquakes. Trenching was accompanied by dating stratigraphy and offset surfaces using luminescence, radiocarbon, and 10Be terrestrial cosmogenic nuclide methods. At Rot Front, trenching of a small scarp did not reveal evidence for surface rupture during the last 5000 years. The scarp rather resembles an extensive debris-flow lobe. At Panfilovkoe, we estimate a Late Pleistocene minimum slip rate of 0.2 ± 0.1 mm/a, averaged over at least two, probably three earthquake cycles. Dip-slip reverse motion along segmented, moderately steep faults resulted in hanging wall collapse scarps during different events. The most recent earthquake occurred around 3.6 ± 1.3 kyr ago (1σ), with dip-slip offsets between 1.2 and 1.4 m. We calculate a probabilistic paleomagnitude to be between 6.7 and 7.2, which is in agreement with regional data from the Kyrgyz range. The morphotectonic signals in the northern Tien Shan are a prime example of deformation in a tectonically active intracontinental mountain belt and as such can help understand the longer-term coevolution of topography and seismogenic processes in similar structural settings worldwide.

  7. Seismicity and active tectonics at Coloumbo Reef (Aegean Sea, Greece): Monitoring an active volcano at Santorini Volcanic Center using a temporary seismic network

    Science.gov (United States)

    Dimitriadis, I.; Karagianni, E.; Panagiotopoulos, D.; Papazachos, C.; Hatzidimitriou, P.; Bohnhoff, M.; Rische, M.; Meier, T.

    2009-02-01

    The volcanic center of Santorini Island is the most active volcano of the southern Aegean volcanic arc. Α dense seismic array consisting of fourteen portable broadband seismological stations has been deployed in order to monitor and study the seismo-volcanic activity at the broader area of the Santorini volcanic center between March 2003 and September 2003. Additional recordings from a neighbouring larger scale temporary network (CYCNET) were also used for the relocation of more than 240 earthquakes recorded by both arrays. A double-difference relocation technique was used, in order to obtain optimal focal parameters for the best-constrained earthquakes. The results indicate that the seismic activity of the Santorini volcanic center is strongly associated with the tectonic regime of the broader Southern Aegean Sea area as well as with the volcanic processes. The main cluster of the epicenters is located at the Coloumbo Reef, a submarine volcano of the volcanic system of Santorini Islands. A smaller cluster of events is located near the Anydros Islet, aligned in a NE-SW direction, running almost along the main tectonic feature of the area under study, the Santorini-Amorgos Fault Zone. In contrast, the main Santorini Island caldera is characterized by the almost complete absence of seismicity. This contrast is in very good agreement with recent volcanological and marine studies, with the Coloumbo volcanic center showing an intense high-temperature hydrothermal activity, in comparison to the corresponding low-level activity of the Santorini caldera. The high-resolution hypocentral relocations present a clear view of the volcanic submarine structure at the Coloumbo Reef, showing that the main seismic activity is located within a very narrow vertical column, mainly at depths between 6 and 9 km. The focal mechanisms of the best-located events show that the cluster at the Coloumbo Reef is associated with the "Kameni-Coloumbo Fracture Zone", which corresponds to the

  8. Linking mantle dynamics, plate tectonics and surface processes in the active plate boundary zones of eastern New Guinea (Invited)

    Science.gov (United States)

    Baldwin, S.; Moucha, R.; Fitzgerald, P. G.; Hoke, G. D.; Bermudez, M. A.; Webb, L. E.; Braun, J.; Rowley, D. B.; Insel, N.; Abers, G. A.; Wallace, L. M.; Vervoort, J. D.

    2013-12-01

    Eastern New Guinea lies within the rapidly obliquely converging Australian (AUS)- Pacific (PAC) plate boundary zone and is characterized by transient plate boundaries, rapidly rotating microplates and a globally significant geoid high. As the AUS plate moved northward in the Cenozoic, its leading edge has been a zone of subduction and arc accretion. The variety of tectonic settings in this region permits assessment of the complex interplay among mantle dynamics, plate tectonics, and surface processes. Importantly, the timescale of tectonic events (e.g., subduction, (U)HP exhumation, seafloor spreading) are within the valid bounds of mantle convection models. A record of changes in bathymetry and topography are preserved in high standing mountain belts, exhumed extensional gneiss domes and core complexes, uplifted coral terraces, and marine sedimentary basins. Global seismic tomography models indicate accumulation of subducted slabs beneath eastern New Guinea at the bottom of the upper mantle (i.e., 250-300 km). Preliminary global-scale backward advected mantle convection models, driven by density inferred from joint seismic-geodynamic tomography models, exhibit large-scale flow associated with these subducted slab remnants and predict the timing and magnitude (up to 1500 m) of dynamic topography change (both subsidence and uplift) since the Oligocene. In this talk we will explore the effects of large-scale background mantle flow and plate tectonics on the evolution of topography and bathymetry in eastern New Guinea, and discuss possible mechanisms to explain basin subsidence and surface uplift in the region.

  9. Active faulting Vs other surface displacing complex geomorphic phenomena. Case studies from a tectonically active area, Abruzzi Region, central Apennines, Italy

    Science.gov (United States)

    Lo Sardo, Lorenzo; Gori, Stefano; Falcucci, Emanuela; Saroli, Michele; Moro, Marco; Galadini, Fabrizio; Lancia, Michele; Fubelli, Giandomenico; Pezzo, Giuseppe

    2016-04-01

    How can be univocally inferred the genesis of a linear surface scarp as the result of an active and capable fault (FAC) in tectonically active regions? Or, conversely, how it is possible to exclude that a scarp is the result of a capable fault activation? Trying to unravel this open questions, we show two ambiguous case studies about the problem of the identification of active and capable faults in a tectonically active area just based on the presence of supposed fault scarps at surface. The selected cases are located in the area comprised between the Middle Aterno Valley Fault (MAVF) and the Campo Imperatore Plain (Abruzzi Region, central Apennines), nearby the epicentral area of the April 6th, 2009 L'Aquila earthquake. In particular, the two case studies analysed are located in a region characterized by a widespread Quaternary faults and by several linear scarps: the case studies of (i) Prata D'Ansidonia area and (ii) Santo Stefano di Sessanio area. To assess the origin and the state of activity of the investigated geomorphic features, we applied a classical geological and geomorphological approach, based on the analysis of the available literature, the interpretation of the aerial photographs, field surveying and classical paleoseismological approach, the latter consisting in digging excavations across the analysed scarps. These analysis were then integrated by morphometrical analyses. As for case (i), we focused on determining the geomorphic "meaning" of linear scarps carved onto fluvial-deltaic conglomerates (dated to the Early Pleistocene; Bertini and Bosi, 1993), up to 3 meters high and up to 1,5 km long, that border a narrow, elongated and flat-bottom depressions, filled by colluvial deposits. These features groove the paleo-landsurface of Valle Daria (Bosi and Bertini, 1970), wide landsurface located between Barisciano and Prata D'Ansidonia. Entwining paleoseismological trenching with geophysical analyses (GPR, ERT and microgravimetrical prospections), it

  10. Plate Tectonic Cycle. K-6 Science Curriculum.

    Science.gov (United States)

    Blueford, J. R.; And Others

    Plate Tectonics Cycle is one of the units of a K-6 unified science curriculum program. The unit consists of four organizing sub-themes: (1) volcanoes (covering formation, distribution, and major volcanic groups); (2) earthquakes (with investigations on wave movements, seismograms and sub-suface earth currents); (3) plate tectonics (providing maps…

  11. Transient sodium current at subthreshold voltages: activation by EPSP waveforms.

    Science.gov (United States)

    Carter, Brett C; Giessel, Andrew J; Sabatini, Bernardo L; Bean, Bruce P

    2012-09-20

    Tetrodotoxin (TTX)-sensitive sodium channels carry large transient currents during action potentials and also "persistent" sodium current, a noninactivating TTX-sensitive current present at subthreshold voltages. We examined gating of subthreshold sodium current in dissociated cerebellar Purkinje neurons and hippocampal CA1 neurons, studied at 37°C with near-physiological ionic conditions. Unexpectedly, in both cell types small voltage steps at subthreshold voltages activated a substantial component of transient sodium current as well as persistent current. Subthreshold EPSP-like waveforms also activated a large component of transient sodium current, but IPSP-like waveforms engaged primarily persistent sodium current with only a small additional transient component. Activation of transient as well as persistent sodium current at subthreshold voltages produces amplification of EPSPs that is sensitive to the rate of depolarization and can help account for the dependence of spike threshold on depolarization rate, as previously observed in vivo.

  12. Cardiac allograft immune activation: current perspectives

    Directory of Open Access Journals (Sweden)

    Chang D

    2014-12-01

    Full Text Available David Chang, Jon Kobashigawa Cedars-Sinai Heart Institute, Los Angeles, CA, USA Abstract: Heart transplant remains the most durable option for end-stage heart disease. Cardiac allograft immune activation and heart transplant rejection remain among the main complications limiting graft and recipient survival. Mediators of the immune system can cause different forms of rejection post-heart transplant. Types of heart transplant rejection include hyperacute rejection, cellular rejection, antibody-mediated rejection, and chronic rejection. In this review, we will summarize the innate and adaptive immune responses which influence the post-heart transplant recipient. Different forms of rejection and their clinical presentation, detection, and immune monitoring will be discussed. Treatment of heart transplant rejection will be examined. We will discuss potential treatment strategies for preventing rejection post-transplant in immunologically high-risk patients with antibody sensitization. Keywords: heart transplant, innate immunity, adaptive immunity, rejection, immunosuppression

  13. The damages of Ksiaz Castle architecture in relation to new informations on the structure and indications of recent tectonic activity in Świebodzice Depression

    Science.gov (United States)

    Kasza, Damian; Kaczorowski, Marek; Zdunek, Ryszard; Wronowski, Roman

    2017-04-01

    First informations about the aspects of recent tectonic activity in Książ area (Świebodzice Depression) come from indications of horizontal pendulums (HP), launched in 1974 in Książ. Over 40-years long series of observation have provided informations about the periods when it came to a sudden change of WP's measuring azimuths. This phenomenon has been interpreted as the result of tilting of rock blocks on which HPs are installed. Recent tectonic activity was confirmed by water-tube tiltmeters (WT) which have recorded episodically appeared events of tiltings of foundation and vertical movements. The consequences of strike-slip movements in Książ area are reflected both in the structure of the Świebodzice Basin (e.g. displacements of geological formations, deformations of the geometry of the Pełcznica River valley) as well as damages of architectural elements of the Książ Castle, where the underground Geodynamic Laboratory of Space Research Centre of Polish Academy of Sciences is located (GL SRC PAS). Tectonic phenomena recorded by both types of tiltmeters (HP and WT) are observed in forms of tilting of foundation and vertical movements. The cause of these effects are horizontal strike-slip movements on the surface of discontinuities (faults) in the Książ massif. From the mechanical point of view faults are the nodes of distribution for these movements. Because of the faults orientation in relation to the main direction of tectonic displacement GL's measuring instruments show transformation of the horizontal component of the movement to vertical movements and tiltings of foundation. Geological and geodetic works carried out in the Książ area allowed for identification and measurement of faults visible in underground corridors of GL. Analysis of the direction parameters of identified surface of discontinuities allowed to build a model of the structure of Książ massif. Created model contains 12 interpreted main zones of dislocation. Determined routes

  14. Andean tectonics: Implications for Satellite Geodesy

    Science.gov (United States)

    Allenby, R. J.

    1984-01-01

    Current knowledge and theories of large scale Andean tectonics as they relate to site planning for the NASA Crustal Dynamics Program's proposed high precision geodetic measurements of relative motions between the Nazca and South American plates are summarized. The Nazca Plate and its eastern margin, the Peru-Chile Trench, is considered a prototype plate marked by rapid motion, strong seismicity and well defined boundaries. Tectonic activity across the Andes results from the Nazca Plate subducting under the South American plate in a series of discrete platelets with different widths and dip angles. This in turn, is reflected in the tectonic complexity of the Andes which are a multitutde of orogenic belts superimposed on each other since the Precambrian. Sites for Crustal Dynamics Program measurements are being located to investigate both interplate and extraplate motions. Observing operations have already been initiated at Arequipa, Peru and Easter Island, Santiago and Cerro Tololo, Chile. Sites under consideration include Iquique, Chile; Oruro and Santa Cruz, Bolivia; Cuzco, Lima, Huancayo and Bayovar, Peru; and Quito and the Galapagos Islands, Ecuador. Based on scientific considerations, Santa Cruz, Huancayo (or Lima), Quito and the Galapagos Islands should be replaced by Isla San Felix, Chile; Brazilia or Petrolina, Brazil; and Guayaquil, Ecuador. If resources permit, additional important sites would be Buenaventura and Villavicencio or Puerto La Concordia, Colombia; and Mendoza and Cordoba, Argentina.

  15. Andean tectonics: Implications for Satellite Geodesy

    Science.gov (United States)

    Allenby, R. J.

    1984-09-01

    Current knowledge and theories of large scale Andean tectonics as they relate to site planning for the NASA Crustal Dynamics Program's proposed high precision geodetic measurements of relative motions between the Nazca and South American plates are summarized. The Nazca Plate and its eastern margin, the Peru-Chile Trench, is considered a prototype plate marked by rapid motion, strong seismicity and well defined boundaries. Tectonic activity across the Andes results from the Nazca Plate subducting under the South American plate in a series of discrete platelets with different widths and dip angles. This in turn, is reflected in the tectonic complexity of the Andes which are a multitutde of orogenic belts superimposed on each other since the Precambrian. Sites for Crustal Dynamics Program measurements are being located to investigate both interplate and extraplate motions. Observing operations have already been initiated at Arequipa, Peru and Easter Island, Santiago and Cerro Tololo, Chile. Sites under consideration include Iquique, Chile; Oruro and Santa Cruz, Bolivia; Cuzco, Lima, Huancayo and Bayovar, Peru; and Quito and the Galapagos Islands, Ecuador. Based on scientific considerations, Santa Cruz, Huancayo (or Lima), Quito and the Galapagos Islands should be replaced by Isla San Felix, Chile; Brazilia or Petrolina, Brazil; and Guayaquil, Ecuador. If resources permit, additional important sites would be Buenaventura and Villavicencio or Puerto La Concordia, Colombia; and Mendoza and Cordoba, Argentina.

  16. Quarternary tectonics, Task 1

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1993-09-30

    Activities conducted for the evaluation of the geology and seismotectonics stability of Yucca Mountain as a potential site for the underground disposal of high-level radioactive wastes continued. Tasks concerned with quaternary tectonics include: scheduling of photography of Little Skull Mountain area; the collection and dating of rock varnish samples from the 1932 Cedar Mountain earthquake area for carbon 14 AMS and cation-ratio analysis; collection of samples for thermoluminescence dating from the 1932 Cedar Mountain earthquake area; mapping of the northern area of Crater Flat; and surveying of the May 17, 1993 Eureka the Valley earthquake area.

  17. Implications for the tectonic transition zone of active orogeny in Hoping drainage basin, by landscape evolution at the multi-temporal timescale

    Science.gov (United States)

    Chang, Q.; Chen, R. F.; Lin, W.; Hsieh, P. S.

    2015-12-01

    In an actively orogeny the landscape are transient state of disequilibrium in response to climatic and tectonic inputs. At the catchment scale, sensitivity of river systems plays an important role in landscape evolution. Hoping drainage basin is located at the tectonic transition zone in the north-eastern Taiwan, where the behavior of Philippine Sea plate switches from overriding above the east-dipping Eurasian Continental plate to northward subducting under the Ryukyu arc. However, extensive deep-seated landslides, debris flow, and numerous large alluvial terraces can be observed, suggesting strong surface processes in this watershed. This effect on regional climate fundamentally changed the landscape by reconfiguring drainage patterns and creating a vast influx of sediments into the basin. In this study we review the morphological evidence from multi-temporal timescale, including in-situ cosmogenic nuclides denudation rate and suspension load data, coupled with the analysis of the longitudinal profiles. The main goal of this study is to compare Holocene erosion rates with thermochronology and radiometric dating of river terraces to investigate the erosion history of Hoping area. The result shows that short-term erosion rate is around twice as large as the long-term denudation rate, which might due to the climate-driven erosion events such as typhoon-induced landslide. We've also mapped detail morphological features by using the high-resolution LiDAR image, which help us to identify not only the landslide but also tectonic features such as lineation, fault scarps, and fracture zones. The tectonic surface features and field investigation results show that the drainage basin is highly fractured, suggesting that even though the vertical tectonic activity rate is small, the horizontal shortening influenced by both southward opening of the back-arc Okinawa trough and the north-western collision in this area is significant. This might cause the reducing in rock strength

  18. DISTRIBUTION OF ELECTRIC CURRENTS IN SOLAR ACTIVE REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Török, T.; Titov, V. S.; Mikić, Z. [Predictive Science, Inc., 9990 Mesa Rim Road, Suite 170, San Diego, CA 92121 (United States); Leake, J. E. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Archontis, V. [School of Mathematics and Statistics, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom); Linton, M. G. [U.S. Naval Research Lab, 4555 Overlook Avenue, SW Washington, DC 20375 (United States); Dalmasse, K.; Aulanier, G. [LESIA, Observatoire de Paris, CNRS, UPMC, Univ. Paris Diderot, 5 place Jules Janssen, F-92190 Meudon (France); Kliem, B. [Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam (Germany)

    2014-02-10

    There has been a long-standing debate on the question of whether or not electric currents in solar active regions are neutralized. That is, whether or not the main (or direct) coronal currents connecting the active region polarities are surrounded by shielding (or return) currents of equal total value and opposite direction. Both theory and observations are not yet fully conclusive regarding this question, and numerical simulations have, surprisingly, barely been used to address it. Here we quantify the evolution of electric currents during the formation of a bipolar active region by considering a three-dimensional magnetohydrodynamic simulation of the emergence of a sub-photospheric, current-neutralized magnetic flux rope into the solar atmosphere. We find that a strong deviation from current neutralization develops simultaneously with the onset of significant flux emergence into the corona, accompanied by the development of substantial magnetic shear along the active region's polarity inversion line. After the region has formed and flux emergence has ceased, the strong magnetic fields in the region's center are connected solely by direct currents, and the total direct current is several times larger than the total return current. These results suggest that active regions, the main sources of coronal mass ejections and flares, are born with substantial net currents, in agreement with recent observations. Furthermore, they support eruption models that employ pre-eruption magnetic fields containing such currents.

  19. Next-generation plate-tectonic reconstructions using GPlates

    OpenAIRE

    2011-01-01

    Plate tectonics is the kinematic theory that describes the large-scale motions and events of the outermost shell of the solid Earth in terms of the relative motions and interactions of large, rigid, interlocking fragments of lithosphere called tectonic plates. Plates form and disappear incrementally over time as a result of tectonic processes. There are currently about a dozen major plates on the surface of the Earth, and many minor ones. The present-day configuration of tectonic plates is il...

  20. Quantitative morphometric analysis for the tectonic characterisation of northern Tunisia.

    Science.gov (United States)

    Camafort, Miquel; Pérez-Peña, José Vicente; Booth-Rea, Guillermo; Ranero, César R.; Gràcia, Eulàlia; Azañón, José Miguel; Melki, Fetheddine; Ouadday, Mohamed

    2016-04-01

    Northern Tunisia is characterized by low deformation rates and low to moderate seismicity. Although instrumental seismicity reaches maximum magnitudes of Mw 5.5, some historical earthquakes have occurred with catastrophic consequences in this region. Aiming to improve our knowledge of active tectonics in Tunisia, we carried out both a quantitative morphometric analysis and field study in the north-western region. We applied different morphometric tools, like river profiles, knickpoint analysis, hypsometric curves and integrals and drainage pattern anomalies in order to differentiate between zones with high or low recent tectonic activity. This analysis helps identifying uplift and subsidence zones, which we relate to fault activity. Several active faults in a sparse distribution were identified. A selected sector was studied with a field campaign to test the results obtained with the quantitative analysis. During the fieldwork we identified geological evidence of recent activity and a considerable seismogenic potential along El Alia-Teboursouk (ETF) and Dkhila (DF) faults. The ETF fault could be responsible of one of the most devastating historical earthquakes in northern Tunisia that destroyed Utique in 412 A.D. Geological evidence include fluvial terraces folded by faults, striated and cracked pebbles, clastic dikes, sand volcanoes, coseismic cracks, etc. Although not reflected in the instrumental seismicity, our results support an important seismic hazard, evidenced by the several active tectonic structures identified and the two seismogenic faults described. After obtaining the current active tectonic framework of Tunisia we discuss our results within the western Mediterranean trying to contribute to the understanding of the western Mediterranean tectonic context. With our results, we suggest that the main reason explaining the sparse and scarce seismicity of the area in contrast with the adjacent parts of the Nubia-Eurasia boundary is due to its extended

  1. Tectonic Framework of the Kachchh Rift Basin

    Science.gov (United States)

    Talwani, P.; Gangopadhyay, A. K.

    2001-05-01

    Evaluation of available geological data has allowed us to determine the tectonic framework of the Kachchh rift basin (KRB), the host to the 1819 Kachchh (MW 7.8), 1956 Anjar ( M 6.0) and the recent January 26, 2001 Bhachau (MW 7.6) earthquakes. The ~ 500 km x 200 km east-west trending KRB was formed during the Mesozoic following the break-up of Gondwanaland. It is bounded to the north and south by the Nagar Parkar and Kathiawar faults which separate it from the Precambrian granitic rocks of the Indian craton. The eastern border is the Radanpur-Barmer arch (defined by an elongate belt of gravity highs) which separates it from the early Cretaceous Cambay rift basin. KRB extends ~ 150 km offshore to its western boundary, the continental shelf. Following India's collision with Eurasia, starting ~ 50 MY ago, there was a stress reversal, from an extensional to the (currently N-S) compressional regime. Various geological observations attest to continuous tectonic activity within the KRB. Mesozoic sediments were uplifted and folded and then intruded by Deccan trap basalt flows in late Cretaceous. Other evidence of continuous tectonic activity include seismically induced soft sediment deformation features in the Upper Jurassic Katrol formation on the Kachchh Mainland and in the Holocene sequences in the Great Rann. Pleistocene faulting in the fluvial sequence along the Mahi River (in the bordering Cambay rift) and minor uplift during late Quaternary at Nal Sarovar, prehistoric and historic seismicity associated with surface deformation further attest to ongoing tectonic activity. KRB has responded to N-S compressional stress regime by the formation of east-west trending folds associated with Allah Bund, Kachchh Mainland, Banni, Vigodi, Katrol Hills and Wagad faults. The Allah Bund, Katrol Hill and Kachchh Mainland faults were associated with the 1819, 1956 and 2001 earthquakes. Northeast trending Median High, Bhuj fault and Rajkot-Lathi lineament cut across the east

  2. Investigating Cenozoic climate change in tectonically active regions with a high-resolution atmospheric general circulation model (ECHAM5)

    Science.gov (United States)

    Mutz, Sebastian; Ehlers, Todd; Li, Jingmin; Werner, Martin; Stepanek, Christian; Lohmann, Gerrit

    2016-04-01

    Studies of Cenozoic palaeo-climates contribute to our understanding of contemporary climate change by providing insight into analogues such as the Pliocene (PLIO), and by evaluation of GCM (General Circulation Models) performance using the Mid-Holocene (MH) and the Last Glacial Maximum (LGM). Furthermore, climate is a factor to be considered in the evolution of ecology, landscapes and mountains, and in the reconstruction of erosion histories. In this study, we use high-resolution (T159) ECHAM5 simulations to investigate pre-industrial (PI) and the the above mentioned palaeo-climates for four tectonically active regions: Alaska (St. Elias Range), the US Northwest Pacific (Cascade Range), western South America (Andes) and parts of Asia (Himalaya-Tibet). The PI climate simulation is an AMIP (Atmospheric Model Intercomparison Project) style ECHAM5 experiment, whereas MH and LGM simulation are based on simulations conducted at the Alfred Wegner Institute, Bremerhaven. Sea surface boundary conditions for MH were taken from coupled atmosphere-ocean model simulations (Wei and Lohmann, 2012; Zhang et al, 2013) and sea surface temperatures and sea ice concentration for the LGM are based on GLAMAP project reconstructions (Schäfer-Neth and Paul, 2003). Boundary conditions for the PLIO simulation are taken from the PRISM (Pliocene Research, Interpretation and Synoptic Mapping) project and the employed PLIO vegetation boundary condition is created by means of the transfer procedure for the PRISM vegetation reconstruction to the JSBACH plant functional types as described by Stepanek and Lohmann (2012). For each of the investigated areas and time slices, the regional simulated climates are described by means of cluster analyses based on the variability of precipitation, 2m air temperature and the intra-annual amplitude of the values. Results indicate the largest differences to a PI climate are observed for LGM and PLIO climates in the form of widespread cooling and warming

  3. Lesser Himalayan sequences in Eastern Himalaya and their deformation: Implications for Paleoproterozoic tectonic activity along the northern margin of India

    Directory of Open Access Journals (Sweden)

    Dilip Saha

    2013-05-01

    Full Text Available Substantial part of the northern margin of Indian plate is subducted beneath the Eurasian plate during the Caenozoic Himalayan orogeny, obscuring older tectonic events in the Lesser Himalaya known to host Proterozoic sedimentary successions and granitic bodies. Tectonostratigraphic units of the Proterozoic Lesser Himalayan sequence (LHS of Eastern Himalaya, namely the Daling Group in Sikkim and the Bomdila Group in Arunachal Pradesh, provide clues to the nature and extent of Proterozoic passive margin sedimentation, their involvement in pre-Himalayan orogeny and implications for supercontinent reconstruction. The Daling Group, consisting of flaggy quartzite, meta-greywacke and metapelite with minor mafic dyke and sill, and the overlying Buxa Formation with stromatolitic carbonate-quartzite-slate, represent shallow marine, passive margin platformal association. Similar lithostratigraphy and broad depositional framework, and available geochronological data from intrusive granites in Eastern Himalaya indicate strikewise continuity of a shallow marine Paleoproterozoic platformal sequence up to Arunachal Pradesh through Bhutan. Multiple fold sets and tectonic foliations in LHS formed during partial or complete closure of the sea/ocean along the northern margin of Paleoproterozoic India. Such deformation fabrics are absent in the upper Palaeozoic–Mesozoic Gondwana formations in the Lesser Himalaya of Darjeeling-Sikkim indicating influence of older orogeny. Kinematic analysis based on microstructure, and garnet composition suggest Paleoproterozoic deformation and metamorphism of LHS to be distinct from those associated with the foreland propagating thrust systems of the Caenozoic Himalayan collisional belt. Two possibilities are argued here: (1 the low greenschist facies domain in the LHS enveloped the amphibolite to granulite facies domains, which were later tectonically severed; (2 the older deformation and metamorphism relate to a Pacific type

  4. NOS CO-OPS Active Currents Data, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has surface Active Currents data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). WARNING: These raw data have not...

  5. Incipient mantle delamination, active tectonics and crustal thickening in Northern Morocco: Insights from gravity data and numerical modeling

    Science.gov (United States)

    Baratin, Laura-May; Mazzotti, Stéphane; Chéry, Jean; Vernant, Philippe; Tahayt, Abdelilah; Mourabit, Taoufik

    2016-11-01

    The Betic-Rif orocline surrounding the Alboran Sea, the westernmost tip of the Mediterranean Sea, accommodates the NW-SE convergence between the Nubia and Eurasia plates. Recent GPS observations indicate a ∼4 mm/yr SW motion of the Rif Mountains, relative to stable Nubia, incompatible with a simple two-plate model. New gravity data acquired in this study define a pronounced negative Bouguer anomaly south of the Rif, interpreted as a ∼40 km-thick crust in a state of non-isostatic equilibrium. We study the correlation between these present-day kinematic and geodynamic processes using a finite-element code to model in 2-D the first-order behavior of a lithosphere affected by a downward normal traction (representing the pull of a high-density body in the upper mantle). We show that intermediate viscosities for the lower crust and uppermost mantle (1021-1022Pas) allow an efficient coupling between the mantle and the base of the brittle crust, thus enabling (1) the conversion of vertical movement, resulting from the downward traction, to horizontal movement and (2) shortening in the brittle upper crust. Our results show that incipient delamination of the Nubian continental lithosphere, linked to slab pull, can explain the present-day abnormal tectonics, contribute to the gravity anomaly observed in northern Morocco, and give insight into recent tectonics in the Western Mediterranean region.

  6. Morphometric analysis of El Salvador Fault Zone. Implications to the tectonic evolution. Central America.

    Science.gov (United States)

    Alonso-Henar, Jorge; Jesús Martínez-Díaz, José; Álvarez-Gómez, José Antonio

    2013-04-01

    It is considered that the study of the recent topography development, and the use of geomorphological indexes are good tools for the quantification of the active tectonics. We have used quantitative geomorphology in order to improve our understanding of the recent activity and tectonic evolution of the El Salvador Fault Zone (ESFZ); an E-W oriented strike-slip fault zone that extends 150 km through El Salvador (Martínez-Díaz et al. 2004). Previous studies propose a transtensive tectonic regime at the Central America Volcanic Arc in El Salvador, which induces relative vertical motions on the faults within El Salvador Fault Zone (i.e. Álvarez-Gómez et al., 2008, Cáceres et al. 2005,). This relative vertical displacement can be quantified with the use of hypsometry as a geomorphological character. The morphometric analysis done contributes to a better understanding of the ESFZ. We have defined km scale tectonic block relative displacements that may be useful to constrain the strain distribution along the ESFZ, length of segments with homogeneous vertical movements and lateral relay of active structures. This study supports the hypothesis of a recent migration in the maximum shortening direction, and the accomodation of the current deformation through the reactivation of pre-existing structures inherited from a previous tectonic frame. A similar tectonic evolution as described Weinberg (1992) in Nicaragua, is interpreted from the results of this study.

  7. Both barium and calcium activate neuronal potassium currents

    Energy Technology Data Exchange (ETDEWEB)

    Ribera, A.B.; Spitzer, N.C.

    1987-09-01

    Amphibian spinal neurons in culture possess both rapidly inactivating and sustained calcium-dependent potassium current components, similar to those described for other cells. Divalent cation-dependent whole-cell outward currents were isolated by subtracting the voltage-dependent potassium currents recorded from Xenopus laevis neurons in the presence of impermeant cadmium from the currents produced without cadmium but in the presence of permeant divalent cations. These concentrations of permeant ions were low enough to avoid contamination by macroscopic inward currents through calcium channels. Calcium-dependent potassium currents were reduced by 1 ..mu..M tetraethylammonium. These currents can also be activated by barium or strontium. Barium as well as calcium activated outward currents in young neurons (6-8 hr) and in relatively mature neurons (19-26 hr in vitro). However, barium influx appeared to suppress the sustained voltage-dependent potassium current in most cells. Barium also activated at least one class of potassium channels observed in excised membrane patches, whole blocking others. The blocking action may have masked and hindered detection of the stimulatory action of barium in other systems.

  8. Late Pleistocene-Holocene uplift driven terrace formation and climate-tectonic interplay from a seismically active intraplate setting: An example from Kachchh, Western India

    Science.gov (United States)

    Prizomwala, S. P.; Das, Archana; Chauhan, G.; Solanki, T.; Basavaiah, N.; Bhatt, Nilesh; Thakkar, M. G.; Rastogi, B. K.

    2016-07-01

    terrace, we reported a minimum uplift rate of 1.04 mm/a for the eastern KMF during the Late Pleistocene-Holocene period, hinting seismically active nature of the KMF during this period. The terrace formation in the eastern Northern Hill Range is mostly regulated by tectonic uplifts along the KMF.

  9. Input of UAV, DTM photo-interpretation and SAR interferometry on active tectonics applied on the Southern Coastal Range (SE Taiwan)

    Science.gov (United States)

    Deffontaines, Benoit; Chang, Kuo-Jen; Champenois, Johann; Magalhaes, Samuel; Serries, Gregory

    2016-04-01

    Taiwan is an excellent geomorphic laboratory where both extreme climatic events and high active tectonics compete. Moreover many Earth Sciences and Environmental data bases exist nowadays that help to better constrain both structural geology and active deformations. The latter unfortunately is still poorly known in the Cosatal Range of E.Taiwan in terms of geology due to access difficulties, high relief, paucity of roads, tropical vegetation and high climatic events (typhoons and heavy rainfall) and so on. Indirect methods such as photogrammetric survey using UAV's helps a lot to get high resolution topographic DEM and DTM, better than 10cm in planimetry, that helps a lot to get through careful photo-interpretation, a bird's eye view of the geology. Therefore we were able to much update the famous pre-existing geological maps (Wang and Chen, 1993). Moreover, by combining our high resolution topographic results with those of SAR interferometry (database of Champenois et al, EPSL, 2012), we were able to identify, characterise and quantify the differential active features toward the LOS of the Coastal Range (eastern Taiwan). In order to synthetise and to model the deformation of that famous place, we herein constructed more than 500 parallel projected profiles in order to locate, characterize and quantify the active tectonic features and compare them to the topography and the updated photo-interpreted geology (this work). We then were able to reconstruct the structural geometry of the Coastal Range and the Longitudinal Valley in SE Taiwan. Among our results, we reveal and prove : 1. the whole 2cm differential surrection of the Coastal Range ; 2. the differential displacement between both Central and Coastal Ranges ; 3. we explain the location of the Pinantashi river situated within the Lichi melange that correspond to the maximum surrection of the Coastal Range ; 4. we reveal the different units and their relative displacement within the Coastal Range itself ; 5. we

  10. Suppression of spontaneous epileptiform activity with applied currents.

    Science.gov (United States)

    Nakagawa, M; Durand, D

    1991-12-20

    It has been well established that both applied and endogenous electric fields can modulate neuronal activity in various preparations. In this paper, we present the effects of applied currents on spontaneous epileptiform activity in the CA1 region of the rat hippocampus. A computer-controlled system was designed to detect the spontaneous abnormal activity and then apply current pulses of programmable amplitude with monopolar electrodes in the stratum pyramidale. The epileptiform activity was generated by subperfusion of the neural tissue with an elevated potassium artificial cerebrospinal fluid (CSF) solution. Extracellular recordings showed that the interictal bursts could be fully suppressed in 90% of the slices by subthreshold currents with an average amplitude of 12.5 microA. Intracellular recordings showed that the anodic currents generated hyperpolarization of the somatic membrane thereby suppressing neuronal firing. This inhibitory effect of applied current pulses is important for the understanding of electric field effects on abnormal neuronal activity and could be an effective means of preventing the spread of epileptiform activity.

  11. Identification of paleoearthquakes based on geomorphological evidence and their tectonic implications for the southern part of the active Anqiu-Juxian fault, eastern China

    Science.gov (United States)

    Jiao, Qisong; Jiang, Wenliang; Zhang, Jingfa; Jiang, Hongbo; Luo, Yi; Wang, Xin

    2016-12-01

    This study utilized an unmanned aerial vehicle (UAV) photogrammetry system to acquire orthoimages and generate a digital elevation model (DEM) covering the southern part of the Anqiu-Juxian fault for geomorphological analysis and paleoearthquake identification. Six offset gullies were identified and analyzed on the orthoimages. Our results indicate that at least three large and several moderate earthquakes have occurred along the fault zone. Knickpoints recognized from the DEM reveal several paleoearthquakes. An average Holocene horizontal slip rate of 2.86 ± 0.35 mm yr-1 was estimated from the offset gullies, which is consistent with previous results from field surveys. The tectonic evolution of this fault zone is most likely related to subduction of the Pacific plate under the Eurasian plate, which gave rise to the right-lateral strike-slip and thrust movement of the Tan-Lu fault zone. This study provided valuable information regarding fault activity and paleoearthquake occurrence along the Anqiu-Juxian fault zone during the Holocene and demonstrated the potential of using UAVs for studies involving tectonic geomorphology.

  12. Electric currents and coronal heating in NOAA active region 6952

    Science.gov (United States)

    Metcalf, T. R.; Canfield, R. C.; Hudson, H. S.; Mickey, D. L.; Wulser, J. -P.; Martens, P. C. H.; Tsuneta, S.

    1994-01-01

    We examine the spatial and temporal relationship between coronal structures observed with the soft X-ray telescope (SXT) on board the Yohkoh spacecraft and the vertical electric current density derived from photospheric vector magnetograms obtained using the Stokes Polarimeter at the Mees Solar Observatory. We focus on a single active region: AR 6952 which we observed on 7 days during 1991 December. For 11 independent maps of the vertical electric current density co-aligned with non-flaring X-ray images, we search for a morphological relationship between sites of high vertical current density in the photosphere and enhanced X-ray emission in the overlying corona. We find no compelling spatial or temporal correlation between the sites of vertical current and the bright X-ray structures in this active region.

  13. ON TECTONIC PROBLEMS OF THE OKINAWA TROUGH

    Institute of Scientific and Technical Information of China (English)

    李乃胜

    2001-01-01

    The Okinawa Trough is a very active tectonic zone at the margin of the Northwest Pacific and is typical of back-arc rifting at the young stage of tectonic evolution. Many scientists from Japan,China, Germany, France, the U. S.A. and Russia have done a lot of geologic and geophysical investigations there. It is well known that the Okinawa Trough is an active back-arc rift with extremely high heat flow, very strong hydrothermal circulation, strong volcanic and magmatic activity, frequent earthquakes,rapid subsidence and rifting, well-developed fault and central graben. But up to now, there are still some important tectonic problems about the Okinawa Trough that require clarification on some aspects such as the type of its crust, its forming time, its tectonic evolution, the distribution of its central grabens, the relationship between its high heat flow and tectonic activity. Based on the data obtained from seismic sur-vey, geomagnetic and gravity measurements, submarine sampling and heat flow measurements in the last 15 years, the author discusses the following tectonic problems about the Okinawa Trough: (1) If the Okinawa Trough develops oceanic crust or not. (2) Is the South Okinawa Trough tectonically more active than the North Okinawa Trough with shallower water and few investigation data on it. (3) The formation time of the Okinawa Trough and its tectonic evolution. The Okinawa Trough has a very thin continental crust. Up to now, there is no evidence of oceanic crust in the Okinawa Trough. The North, Middle and South Okinawa Trough are all very strongly active areas. From 6 Ma B.P. , the Okinawa Trough began to form. Since 2 Ma, the Okinawa Trough has been very active.

  14. ON TECTONIC PROBLEMS OF THE OKINAWA TROUGH

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Okinawa Trough is a very active tectonic zone at the margin of the Northwest Pacific and is typical of back-arc rifting at the young stage of tectonic evolution. Many scientists from Japan, China, Germany, France, the U.S.A. and Russia have done a lot of geologic and geophysical investigations there. It is well known that the Okinawa Trough is an active back-arc rift with extremely high heat flow, very strong hydrothermal circulation, strong volcanic and magmatic activity, frequent earthquakes, rapid subsidence and rifting, well-developed fault and central graben. But up to now, there are still some important tectonic problems about the Okinawa Trough that require clarification on some aspects such as the type of its crust, its forming time, its tectonic evolution, the distribution of its central grabens, the relationship between its high heat flow and tectonic activity. Based on the data obtained from seismic survey, geomagnetic and gravity measurements, submarine sampling and heat flow measurements in the last 15 years, the author discusses the following tectonic problems about the Okinawa Trough: (1) If the Okinawa Trough develops oceanic crust or not. (2) Is the South Okinawa Trough tectonically more active than the North Okinawa Trough with shallower water and few investigation data on it. (3) The formation time of the Okinawa Trough and its tectonic evolution. The Okinawa Trough has a very thin continental crust. Up to now, there is no evidence of oceanic crust in the Okinawa Trough. The North, Middle and South Okinawa Trough are all very strongly active areas. From 6 Ma B.P., the Okinawa Trough began to form. Since 2 Ma, the Okinawa Trough has been very active.

  15. Towards a Tectonic Approach

    DEFF Research Database (Denmark)

    Hvejsel, Marie Frier; Kirkegaard, Poul Henning; Mortensen, Sophie Bondgaard

    2015-01-01

    through this transformation is inevitably a tectonic question. By analyzing three historical examples, Adolf Loos’ Villa Moller, Le Corbusier’s Unité d’Habitation, and Frank Lloyd Wright’s Johnson Wax Administration Building, chosen for their tectonic ability to exploit the technical ‘principle’ defining...

  16. A paradigm shift in predicting stormflow responses in an active tectonic region through a similarity analysis of pressure propagation in a hydraulic continuum

    Directory of Open Access Journals (Sweden)

    Makoto Tani

    2013-06-01

    Full Text Available Soil layers on hillslopes acts as systems in quasi-steady states generating rainfall-stormflow responses that are controlled by pressure propagation in a hydraulic continuum established when the rainfall volume is sufficiently large. A similarity analysis for quantifying the sensitivity of the stormflow response and recession limb to topographic and soil properties in a sloping permeable domain showed that the deviation of stormflow responses in the hydraulic continuum decreases due to the macropore effect. The rapid responses seem to be naturally derived from the evolution of the soil layer with the assistance of the vegetation-root system and effective drainage systems in zero-order catchments in active tectonic regions with heavy storms. To predict stormflow responses using distributed runoff models, a paradigm shift to consider this evolution process is needed because the simple stormflow responses and complex and heterogeneous catchment properties are poorly related, but may be mainly determined by soil evolution processes.

  17. Combined effects of Eurasia/Sunda oblique convergence and East-Tibetan crustal flow on the active tectonics of Burma

    Science.gov (United States)

    Rangin, Claude; Maurin, Thomas; Masson, Frederic

    2013-10-01

    It is widely accepted that deformation of the India/Sunda plate is the result of partitioned hyper oblique convergence. Presently, sub-meridian dextral strike slip faulting accommodates this India/Sunda motion in a buffer zone, the Burma platelet. This wide dextral strike slip shear zone is complicated by the side effect of the Tibet plateau collapse that can be described in term of crustal flow and gravity tectonics. The loss of potential energy related to this plateau collapse affects most of the Burmese platelet particularly in its northernmost part. Interaction of these two distinct geodynamic processes is recorded in the GPS based regional strain field, the analysis of seismic focal mechanism but also from direct geologic observations both onshore and offshore Myanmar and Bangladesh. We propose the apparent E-W shortening component of this so called partitioned hyper-oblique subduction is only the effect of regional gravitational forces related to the Tibet plateau collapse whereas the NS strike slip faulting accommodates the India/Sunda motion.

  18. Plate tectonics conserves angular momentum

    Directory of Open Access Journals (Sweden)

    C. Bowin

    2009-03-01

    features, and fracture zones (and wedge-shaped sites of seafloor spreading are adjustment zones that accommodate strains in the lithosphere. Further, the interlocked pattern of the Australian and Pacific plates the past 42 Million years (with their absolute plate motions near 90° to each other is taken as strong evidence that large thermally driven "roller" convection cells previously inferred as the driving mechanism in earlier interpretations of continental drift and plate tectonics, have not been active in the Earth's mantle the past 42 Million years, if ever. This report also presents estimates of the changes in location and magnitude of the Earth's axis of total plate tectonic angular momentum for the past 62 million years.

  19. Slope instability induced by volcano-tectonics as an additional source of hazard in active volcanic areas: the case of Ischia island (Italy)

    Science.gov (United States)

    Della Seta, Marta; Marotta, Enrica; Orsi, Giovanni; de Vita, Sandro; Sansivero, Fabio; Fredi, Paola

    2012-01-01

    Ischia is an active volcanic island in the Gulf of Naples whose history has been dominated by a caldera-forming eruption (ca. 55 ka) and resurgence phenomena that have affected the caldera floor and generated a net uplift of about 900 m since 33 ka. The results of new geomorphological, stratigraphical and textural investigations of the products of gravitational movements triggered by volcano-tectonic events have been combined with the information arising from a reinterpretation of historical chronicles on natural phenomena such as earthquakes, ground deformation, gravitational movements and volcanic eruptions. The combined interpretation of all these data shows that gravitational movements, coeval to volcanic activity and uplift events related to the long-lasting resurgence, have affected the highly fractured marginal portions of the most uplifted Mt. Epomeo blocks. Such movements, mostly occurring since 3 ka, include debris avalanches; large debris flows (lahars); smaller mass movements (rock falls, slumps, debris and rock slides, and small debris flows); and deep-seated gravitational slope deformation. The occurrence of submarine deposits linked with subaerial deposits of the most voluminous mass movements clearly shows that the debris avalanches impacted on the sea. The obtained results corroborate the hypothesis that the behaviour of the Ischia volcano is based on an intimate interplay among magmatism, resurgence dynamics, fault generation, seismicity, slope oversteepening and instability, and eruptions. They also highlight that volcano-tectonically triggered mass movements are a potentially hazardous phenomena that have to be taken into account in any attempt to assess volcanic and related hazards at Ischia. Furthermore, the largest mass movements could also flow into the sea, generating tsunami waves that could impact on the island's coast as well as on the neighbouring and densely inhabited coast of the Neapolitan area.

  20. The Current State of Marketing Activity among Higher Education Institutions.

    Science.gov (United States)

    Newman, Cynthia M.

    2002-01-01

    Investigated the current state of marketing, marketing research, and planning practices at four-year higher education institutions. Builds upon previous studies by Blackburn (1979) and Goldgehn (1982 and 1989). Determined whether the use and apparent understanding of marketing and its attendant activities by admissions and enrollment management…

  1. Unraveling the tectonic evolution of a Neoproterozoic-Cambrian active margin in the Ribeira Orogen (Se Brazil): U-Pb and Lu-Hf provenance data

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Gabriel Lamounier de F. [Servico Geologico do Estado do Rio de Janeiro (DRM-RJ), Niteroi, RJ (Brazil); Schmitt, Renata; Bongiolo, Everton M.; Mendes, Julio [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Basei, Miguel S. [Universidade de Sao Paulo (USP), SP (Brazil)

    2015-07-01

    Full text: The Neoproterozoic-Ordovician Central Ribeira Orogen, in SE Brazil, presents two contrasting tectonic domains in its southern portion: (a) The Arc Domain constituted of Neoproterozoic to Paleozoic magmatic rocks and low P-high T metamorphic para (Sao Fidelis Group) - and ortho- derived units (in Oriental Terrane); and (b) The Basement Domain, constituted of a Paleoproterozoic and Neoproterozoic medium P-high T metamorphic para (Palmital-Buzios Succession)- and ortho-derived units (in Cabo Frio Tectonic Domain). Our work focuses on paraderived rocks sequences from both domains. The provenance analysis using U-Pb and Lu-Hf in zircon grains is presented here as an effective tool to unravel the paleogeography and nature of the pre-collisional sedimentary basins. We performed 505 analyses (U-Pb) on detrital zircon grains and some metamorphic overgrowths from six paragneiss samples. Besides, 141 analyses (Lu-Hf) in six samples only on the detrital zircon grains domains. All samples present a main peak from Neoproterozoic sources (750-570 Ma) and the other minor peak in the Stenian/Tonian periods (1200-850Ma), this indicate an orogenic contribution for this basin. Scarce register from the Mesoproterozoic and two peaks in the Archean/Paleoproterozoic (2.6 and 1.9 Ga) are recognized as a contribution from an ancient continent. The Lu-Hf data reveals a juvenile source for the detrital zircon grains from Buzios Succession while Palmital and Sao Fidelis Group units show a main crustal signature for their detrital zircon population. Based on the U-Pb and Lu-Hf data presented here, plus petrological data, geological correlations, and compilation of data from literature, we propose a tectonic model for the origin of para-derived rocks from the eastern part of the Ribeira Orogen. Starting with an extensional environment of ca. 600 Ma in a back-arc basin (Buzios succession deposition) and continuing as an active margin between 570 and 550 Ma in the fore-arc and prism

  2. A multidisciplinary approach for the study of the effects of active tectonics along the North Anatolian fault zone: possibilities for the application of the electrical self potential method

    Directory of Open Access Journals (Sweden)

    W. Balderer

    1994-06-01

    Full Text Available The aims of this joint interdisciplinary project “Marmara” of ETH Zurich and the Istanbul Technical University (ITO are to study the effects of active tectonics as evidenced by geology, geodesy and seismology on hydrogeology and geothermics in selected areas along the North Anatolian fault zone. Within the framework of this project thermal water systems in seven different areas have been investigated or are under investigation up to now (SchindIer et al., 1993. For three study areas along the North Anatolian fault zone (from east to west of Kuzuluk/Adapazari, Bursa and of Canakkale the investigations with respect to the geological and hydrogeological features are complete. The now possible hydrogeological characterisation shows encouraging possibilities for the application of new methods like the electrical self potential method for the following reasons: 1 a fully interdisciplinary approach, including seismic survey with especially conceived network, geodetic survey to investigate tectonic movements by the GPS method, geothermic survey combined with geological mapping and hydrogeological investigations of normal mineral and thermal waters; 2 groundwaters of very different chemical and isotopical composition e.g.: Ca-HCO3-type thermal waters of up to 82 °C temperature and total mineralisation of 500 mg/I to 1500 mg/I in the Bursa area, Na-HCO3-type cold mineral waters of up to 2500 mg/I to thermal waters of same mineralisation of up to 80 °C temperature, containing large amounts of CO2 of up to 1 l per 1 kg of water (at surface conditions in the Kuzuluk area and Na-Cl-type waters presenting real thermal brines of up to 65 000 mg/I of total mineralisation and temperatures of up to 100 °C in the Canakkale area; 3 distinct types of hydrodynamic flow regime in areas of different geological and tectonic structure. Based on the results of the investigations within these areas the possibilities of further studies including self potential methods

  3. Current status of research and related activities in NAA application

    Energy Technology Data Exchange (ETDEWEB)

    Ab. Khalik bin Haji Wood [Malaysia Institute for Nuclear Technology Research, Bangi, Selangor (Malaysia)

    1999-10-01

    Current activities of Analytical Chemistry Group of MINT (Malaysia Institute for Nuclear Technology Research) laboratory for elemental analysis of trace amounts in environmental samples such as air particulate matter (on air filter), soils/sediments, water, flora/fauna, oil sludge/waste sludge, and tailing/blasting slag and others, utilizing particularly NAA (Neutron Activation Analysis) method are reviewed. The laboratory participates in the IAEA-organized Interlaboratory Comparison Studies to ensure the analytical system. Other activities include analytical chemistry services with ICP-mass spectrometry and GC/GCMS to compliment the NAA and, moreover, air and marine pollution studies with participation in the UNDP/RCA/IAEA project. (S. Ohno)

  4. Mesozoic and Cenozoic tectonic evolution of the Longmenshan fault belt

    Institute of Scientific and Technical Information of China (English)

    WANG; ErChie

    2009-01-01

    The giant earthquake(Ms=8.0) in Wenchuan on May 12,2008 was triggered by oblique convergence between the Tibetan Plateau and the South China along the Longmenshan fault belt.The Longmenshan fault belt marks an important component of the tectonic and geomorphological boundary between the eastern and western part of China and has a protracted tectonic history.It was first formed as an intracontinental transfer fault,patitioning the differential deformation between the Pacific and Tethys tectonic domains,initiated in late Paleozoic-early Mesozoic time,then served as the eastern boundary of the Tibetan Plateau to accommodate the growth of the plateau in Cenozoic.Its current geological and geomorphological frameworks are the result of superimposition of these two tectonic events.In Late Triassic,the Longmenshan underwent left-slip oblique NW-SE shortening due to the clockwise rotation of the Yangtze Block,which led to the flexural subsidence of the Sichuan foreland basin,but after that,the subsidence of the Sichuan Basin seems no longer controlled by the tectonic activity of the Longmenshan fault belt.The Meosozoic tectonic evolution of the Songpan-Ganzi fold belt differs significantly compared with that of the Yangtze Platform,featured by intensive northeast and southwest shortening and resulted in the close of the Paleo-Tethys.Aerial photos taken immediately after main shock of the giant May 12,2008 earthquake have documented extensive rock fall and landslides that represent one of the most destructive aspects of the earthquake.Both rock avalanches and landslides delivered a huge volume of debris into the middle part of the Minjiang River,and formed many dammed lakes.Breaching of these natural dams can be catastrophic,as occurred in the Diexi area along the upstream of the Minjiang River in the year of 1933 that led to devastating floodings.The resultant flood following the breaching of these dams flowed through and out of the Longmenshan belt into the Chengdu Plain

  5. Mesozoic and Cenozoic tectonic evolution of the Longmenshan fault belt

    Institute of Scientific and Technical Information of China (English)

    WANG ErChie; MENG QingRen

    2009-01-01

    The giant earthquake (MS=8.0) in Wenchuan on May 12, 2008 was triggered by oblique convergence between the Tibetan Plateau and the South China along the Longmenshan fault belt. The Longmenshan fault belt marks an important component of the tectonic and geomorphological boundary between the eastern and western part of China and has a protracted tectonic history. It was first formed as an intracontinental transfer fault, patitioning the differential deformation between the Pacific and Tethys tectonic domains, initiated in late Paleozoic-early Mesozoic time, then served as the eastern boundary of the Tibetan Plateau to accommodate the growth of the plateau in Cenozoic. Its current geological and geomorphological frameworks are the result of superimposition of these two tectonic events. In Late Triassic, the Longmenshan underwent left-slip oblique NW-SE shortening due to the clockwise rotation of the Yangtze Block, which led to the flexural subsidence of the Sichuan foreland basin, but after that, the subsidence of the Sichuan Basin seems no longer controlled by the tectonic activity of the Longmenshan fault belt. The Meosozoic tectonic evolution of the Songpan-Ganzi fold belt differs significantly compared with that of the Yangtze Platform, featured by intensive northeast and southwest shortening and resulted in the close of the Paleo-Tethys. Aerial photos taken immediately after main shock of the giant May 12, 2008 earthquake have documented extensive rock fall and landslides that represent one of the most destructive aspects of the earthquake. Both rock avalanches and landslides delivered a huge volume of debris into the middle part of the Minjiang River, and formed many dammed lakes. Breaching of these natural dams can be catastrophic, as occurred in the Diexi area along the upstream of the Minjiang River in the year of 1933 that led to devastating floodings. The resultant flood following the breaching of these dams flowed through and out of the Longmenshan belt

  6. Constraining fault activity by investigating tectonically-deformed Quaternary palaeoshorelines using a synchronous correlation method: the Capo D'Orlando Fault as a case study (NE Sicily, Italy)

    Science.gov (United States)

    Meschis, Marco; Roberts, Gerald P.; Robertson, Jennifer

    2016-04-01

    Long-term curstal extension rates, accommodated by active normal faults, can be constrained by investigating Late Quaternary vertical movements. Sequences of marine terraces tectonically deformed by active faults mark the interaction between tectonic activity, sea-level changes and active faulting throughout the Quaternary (e.g. Armijo et al., 1996, Giunta et al, 2011, Roberts et al., 2013). Crustal deformation can be calculated over multiple seismic cycles by mapping Quaternary tectonically-deformed palaeoshorelines, both in the hangingwall and footwall of active normal faults (Roberts et al., 2013). Here we use a synchronous correlation method between palaeoshorelines elevations and the ages of sea-level highstands (see Roberts et al., 2013 for further details) which takes advantage of the facts that (i) sea-level highstands are not evenly-spaced in time, yet must correlate with palaeoshorelines that are commonly not evenly-spaced in elevation, and (ii) that older terraces may be destroyed and/or overprinted by younger highstands, so that the next higher or lower paleoshoreline does not necessarily correlate with the next older or younger sea-level highstand. We investigated a flight of Late Quaternary marine terraces deformed by normal faulting as a result of the Capo D'Orlando Fault in NE Sicily (e.g. Giunta et al., 2011). This fault lies within the Calabrian Arc which has experienced damaging seismic events such as the 1908 Messina Straits earthquake ~ Mw 7. Our mapping and previous mapping (Giunta et al. (2011) demonstrate that the elevations of marine terraces inner edges change along the strike the NE - SW oriented normal fault. This confirms active deformation on the Capo D'Orlando Fault, strongly suggesting that it should be added into the Database of Individual Seismogenic Sources (DISS, Basili et al., 2008). Giunta et al. (2011) suggested that uplift rates and hence faults lip-rates vary through time for this examples. We update the ages assigned to

  7. Sericitic alteration at the La Crocetta deposit (Elba Island, Italy): interplay between magmatism, tectonics and hydrothermal activity

    Science.gov (United States)

    Maineri, Cinzia; Benvenuti, Marco; Costagliola, Pilar; Dini, Andrea; Lattanzi, Pierfranco; Ruggieri, Giovanni; Villa, Igor M.

    2003-01-01

    The La Crocetta mine near Porto Azzurro (Elba Island, Tuscany, Italy) is an important producer of raw material for the ceramic industry. Exploitation focuses on a pervasively sericitized porphyritic aplite of the Tuscan Magmatic Province, locally known as "eurite", which underwent significant potassium enrichment during sericitic alteration. Eurites are located along the hanging wall of the Elba Centrale Fault, a low-angle extensional lineament of regional significance. A later carbonatization stage, apparently associated with high-angle extensional tectonics, locally overprinted the sericitized facies. It is expressed by carbonate ± pyrite ± quartz veins, with adverse effects on ore quality. Sericitization was accompanied by addition of potassium, and loss of Na (± Ca, Fe). Rubidium was not enriched along with potassium during sericitization, contrary to what would be expected for interaction with late-magmatic fluids. New 40Ar-39Ar data from eurites provide an isochron age of about 6.7 Ma for the sericitization, whereas the age of the unaltered protolith is ca. 8.8 Ma. Field evidence indicates the Elba Centrale Fault to be the main channel for the hydrothermal fluids. On the other hand, the involvement of heat and/or fluids contributed by the Porto Azzurro pluton, which crops out in the La Crocetta area, is ruled out by field, geochemical and geochronological data (40Ar-39Ar age of Porto Azzurro =5.9 Ma, i.e. significantly younger than the sericitization event). Fluid inclusion studies suggest that sericitization was associated with a low-temperature (Springer LINK server located at http://dx.doi.org/10.1007/s00126-002-0279-2.

  8. Current concepts of active vasodilation in human skin

    Science.gov (United States)

    Wong, Brett J.; Hollowed, Casey G.

    2017-01-01

    ABSTRACT In humans, an increase in internal core temperature elicits large increases in skin blood flow and sweating. The increase in skin blood flow serves to transfer heat via convection from the body core to the skin surface while sweating results in evaporative cooling of the skin. Cutaneous vasodilation and sudomotor activity are controlled by a sympathetic cholinergic active vasodilator system that is hypothesized to operate through a co-transmission mechanism. To date, mechanisms of cutaneous active vasodilation remain equivocal despite many years of research by several productive laboratory groups. The purpose of this review is to highlight recent advancements in the field of cutaneous active vasodilation framed in the context of some of the historical findings that laid the groundwork for our current understanding of cutaneous active vasodilation.

  9. Comparison of excitatory currents activated by different transmitters on crustacean muscle. II. Glutamate-activated currents and comparison with acetylcholine currents present on the same muscle.

    Science.gov (United States)

    Lingle, C; Auerbach, A

    1983-04-01

    The properties of glutamate-activated excitatory currents on the gm6 muscle from the foregut of the spiny lobsters Panulirus argus and interruptus and the crab Cancer borealis were examined using either noise analysis, analysis of synaptic current decays, or slow iontophoretic currents. The properties of acetylcholine currents activated in nonjunctional regions of the gm6 muscle were also examined. At 12 degrees C and -80 mV, the predominant time constant of power spectra from glutamate-activated current noise was approximately 7 ms and the elementary conductance was approximately 34 pS. At 12 degrees C and -80 mV, the predominant time constant of acetylcholine-activated channels was approximately 11 ms with a conductance of approximately 12 pS. Focally recorded glutamatergic extracellular synaptic currents on the gm6 muscle decayed with time constants of approximately 7-8 ms at 12 degrees C and -80 mV. The decay time constant was prolonged e-fold about every 225-mV hyperpolarization in membrane potential. The Q10 of the time constant of the synaptic current decay was approximately 2.6. The voltage dependence of the steady-state conductance increase activated by iontophoretic application of glutamate has the opposite direction of the steady-state conductance activated by cholinergic agonists when compared on the gm6 muscles. The glutamate-activated conductance increase is diminished with hyperpolarization. The properties of the marine crustacean glutamate channels are discussed in relation to glutamate channels in other organisms and to the acetylcholine channels found on the gm6 muscle and the gm1 muscle of the decapod foregut (Lingle and Auerbach, 1983).

  10. Active current control in wind power plants during grid faults

    DEFF Research Database (Denmark)

    Martinez, Jorge; Kjær, Phillip C.; Rodriguez, Pedro

    2010-01-01

    , wind turbines usually have solutions that enable the turbines to control the generation of reactive power during faults. This paper addresses the importance of using an optimal injection of active current during faults in order to fulfil these grid codes. This is of relevant importance for severe......Modern wind power plants are required and designed to ride through faults in electrical networks, subject to fault clearing. Wind turbine fault current contribution is required from most countries with a high amount of wind power penetration. In order to comply with such grid code requirements...

  11. Tectonic Motion of Malaysia: Analysis from Years 2001 TO 2013

    Science.gov (United States)

    Gill, J.; Shariff, N. S.; Omar, K.; Amin, Z. M.

    2015-10-01

    This paper seeks to investigate the tectonic motion of Malaysia using the Malaysian Active GPS Station (MASS) and Malaysia Realtime Kinematic GNSS Network (MyRTKnet) data from years 2001 to 2013. GNSS data were processed using Bernese 5.0, and plotted as a time series; whereby the period before and after the 2004 Sumatra-Andaman mega earthquake are plotted separately. From the time series, episodic events and stable inter-seismic deformation period are analysed. The results indicate that the 2001- 2004 and 2008-2011 periods were free from episodic events; hence, chosen to depict the tectonic motion of Malaysia before and after 2004 Sumatra-Andaman earthquake, respectively. The motion had a major change in direction and rate, especially for East Malaysia and South Peninsular Malaysia. This indicates there exist a long-term post-seismic deformation due to the 2004 mega earthquake. Nonetheless, the 2008-2011 inter-seismic period is stable, and suitable to represent the current long-term tectonic motion of Malaysia: Peninsular and East Malaysia moves south-east, at an average velocity of 0.89 ±0.01 cm/yr south and 1.70 ±0.02 cm/yr east, and 1.06 ±0.01 cm/yr south and 2.50 ±0.02 cm/yr east, respectively. In addition, the co-seismic motion for the 2005 Nias, 2007 Bengkulu and 2012 Northern Sumatra earthquakes after the 2004 Sumatra-Andaman earthquake are relatively small, indicating these three earthquakes have no significant contribution to the long-term tectonic motion of Malaysia. Overall, this paper aims to provide a general insight into the tectonic motion of Malaysia which, expectedly, may benefit other scientific fields.

  12. Rheology and deep tectonics

    Directory of Open Access Journals (Sweden)

    G. Ranalli

    1997-06-01

    Full Text Available The distribution of the rheological properties of the lithosphere in space, and their variations in time, have a profound effect on the resulting tectonic deformation. A classical way of estimating these properties makes use of rheological profiles (strength envelopes. Although rheological profiles are based on assumptions and approximations which limit their resolving power, they are an efficient first-order tool for the study of lithosphere rheology, and their application clarifies the dynamics of tectonic processes. Two examples of the interaction of rheology and tectonics are discussed, namely, the post-orogenic relaxation of Moho topography (which is an additional factor to be considered in tectonic inversion, and the strength control on the level of necking in extension (which may lead to apparent local isostasy at passive continental margins and in sedimentary basins.

  13. Fast inhibition of glutamate-activated currents by caffeine.

    Directory of Open Access Journals (Sweden)

    Nicholas P Vyleta

    Full Text Available BACKGROUND: Caffeine stimulates calcium-induced calcium release (CICR in many cell types. In neurons, caffeine stimulates CICR presynaptically and thus modulates neurotransmitter release. METHODOLOGY/PRINCIPAL FINDINGS: Using the whole-cell patch-clamp technique we found that caffeine (20 mM reversibly increased the frequency and decreased the amplitude of miniature excitatory postsynaptic currents (mEPSCs in neocortical neurons. The increase in mEPSC frequency is consistent with a presynaptic mechanism. Caffeine also reduced exogenously applied glutamate-activated currents, confirming a separate postsynaptic action. This inhibition developed in tens of milliseconds, consistent with block of channel currents. Caffeine (20 mM did not reduce currents activated by exogenous NMDA, indicating that caffeine block is specific to non-NMDA type glutamate receptors. CONCLUSIONS/SIGNIFICANCE: Caffeine-induced inhibition of mEPSC amplitude occurs through postsynaptic block of non-NMDA type ionotropic glutamate receptors. Caffeine thus has both pre and postsynaptic sites of action at excitatory synapses.

  14. Tectonic vocabulary and materialization: Discourse on the future of tectonic architectural research in the Nordic countries

    DEFF Research Database (Denmark)

    Beim, Anne; Bundgaard, Charlotte; Hvejsel, Marie Frier

    2015-01-01

    By referring to the fundamental question of how we unite aesthetics and technology – tectonic theory is necessarily a focal point in the development of the architectural discipline. However, a critical reconsideration of the role of tectonic theory seems necessary when facing the present everyday...... architectural practice. In this matter the paper focuses on the need to juxtapose theoretical studies, to bring the present vocabulary of the tectonic further, as well as to spur further practical experiments enabling theory to materialize in the everyday of the current practice....

  15. Recent seismicity of Italy: Active tectonics of the central Mediterranean region and seismicity rate changes after the Mw 6.3 L'Aquila earthquake

    Science.gov (United States)

    Chiarabba, Claudio; De Gori, Pasquale; Mele, Francesco Mariano

    2015-01-01

    In this paper we present a new image of the instrumental seismicity of Italy, obtained by refining hypocentral determinations for about 100,000 earthquakes that occurred in the period 2005-2012. The improved locations yield new constraints on active tectonics of the central Mediterranean area, where prolonged interaction between nested plates and continental slivers led to the development of the Alpine and Apennines systems. Intermediate-depth and deep earthquakes define a lateral heterogeneous process of delamination and sinking of the continental lithosphere active beneath the mountain belts. Shallow seismicity prevalently occurs beneath elevated topography and correlates with low velocity mantle anomalies, suggesting a superposition of gravity-related forces to the Eurasia-Africa plate convergence. The delamination process drives a paired system of compression and extension that stretches the mountain range while shortening the external side of the belts. The updated seismic catalog permits us to resolve a sharp variation of seismic rates that occurred in recent years, timely after the 2009 Mw 6.3 L'Aquila earthquake. The increase of seismic rates is reasonably due to regional-scale perturbation of the stress field induced by fluid flow and pore-pressure variations within the crust, probably related to deep dehydration processes active beneath the mountain belt.

  16. Plate tectonics on Venus

    Science.gov (United States)

    Anderson, D. L.

    1981-01-01

    The high surface temperature of Venus implies a permanently buoyant lithosphere and a thick basaltic crust. Terrestrial-style tectonics with deep subduction and crustal recycling is not possible. Overthickened basaltic crust partially melts instead of converting to eclogite. Because mantle magmas do not have convenient access to the surface the Ar-40 abundance in the atmosphere should be low. Venus may provide an analog to Archean tectonics on the earth.

  17. Plate tectonics on Venus

    Science.gov (United States)

    Anderson, D. L.

    1981-01-01

    The high surface temperature of Venus implies a permanently buoyant lithosphere and a thick basaltic crust. Terrestrial-style tectonics with deep subduction and crustal recycling is not possible. Overthickened basaltic crust partially melts instead of converting to eclogite. Because mantle magmas do not have convenient access to the surface the Ar-40 abundance in the atmosphere should be low. Venus may provide an analog to Archean tectonics on the earth.

  18. Calculation of regional geomorphic indices to constrain the mechanisms of tectonic uplift and active deformation of the Island of Puerto Rico

    Science.gov (United States)

    Martinez, S.

    2016-12-01

    The island of Puerto Rico in the northern Caribbean covers an area of about 14,000 km2 and is 180 km long and 65 km wide and is densely populated by 3.4 million persons. The island is mountainous with an east-west-trending, central mountain range with its highest point of 1338 m in the geographic center of the island. Previous workers have suggested that the origin of this east-west, Central Cordillera is active uplift and folding of a large, east-west-trending anticline whose fold axis is coincident with the topographic crest of the Cordillera Central. The folding mechanism has been attributed by previous workers to obliquely-subducting slabs of the North American and Caribbean plates beneath the island. To test the hypothesis that this topographic and structural axis is also the axis of active topographic uplift, I created a knickpoint density map for the island based on over 50 different river systems to reveal areas of active uplift. The knickpoint map shows an excellent correlation with the proposed arch both in width and trend of the axis and supports the conclusion that the arch is the main axis of active uplift on the Island. I also calculated geomorphic indices for 21 different watersheds of the island that include the Hypsometric Integral and a Stream Length Gradient Index that both assess tectonic activity based on stream and watershed behaviors. The Hack index and Hypsometric Integral show that the most active area of uplift is located in the central and north-central parts of the island that include about one half of the length of the proposed, east-west-trending arch. The two topographically-elevated ends of the arch in the western and eastern parts of the island are less active, according to the indices. Lower values in these areas may be influenced by higher amounts of precipitations in these areas.

  19. Episodic plate tectonics on Venus

    Science.gov (United States)

    Turcotte, Donald

    1992-01-01

    Studies of impact craters on Venus from the Magellan images have placed important constraints on surface volcanism. Some 840 impact craters have been identified with diameters ranging from 2 to 280 km. Correlations of this impact flux with craters on the Moon, Earth, and Mars indicate a mean surface age of 0.5 +/- 0.3 Ga. Another important observation is that 52 percent of the craters are slightly fractured and only 4.5 percent are embayed by lava flows. These observations led researchers to hypothesize that a pervasive resurfacing event occurred about 500 m.y. ago and that relatively little surface volcanism has occurred since. Other researchers have pointed out that a global resurfacing event that ceased about 500 MYBP is consistent with the results given by a recent study. These authors carried out a series of numerical calculations of mantle convection in Venus yielding thermal evolution results. Their model considered crustal recycling and gave rapid planetary cooling. They, in fact, suggested that prior to 500 MYBP plate tectonics was active in Venus and since 500 MYBP the lithosphere has stabilized and only hot-spot volcanism has reached the surface. We propose an alternative hypothesis for the inferred cessation of surface volcanism on Venus. We hypothesize that plate tectonics on Venus is episodic. Periods of rapid plate tectonics result in high rates of subduction that cool the interior resulting in more sluggish mantle convection.

  20. Upper plate deformation and seismic barrier in front of Nazca subduction zone: The Chololo Fault System and active tectonics along the Coastal Cordillera, southern Peru

    Science.gov (United States)

    Audin, Laurence; Lacan, Pierre; Tavera, Hernando; Bondoux, Francis

    2008-11-01

    The South America plate boundary is one of the most active subduction zone. The recent Mw = 8.4 Arequipa 2001 earthquake ruptured the subduction plane toward the south over 400 km and stopped abruptly on the Ilo Peninsula. In this exact region, the subduction seismic crisis induced the reactivation of continental fault systems in the coastal area. We studied the main reactivated fault system that trends perpendicular to the trench by detailed mapping of fault related-geomorphic features. Also, at a longer time scale, a recurrent Quaternary transtensive tectonic activity of the CFS is expressed by offset river gullies and alluvial fans. The presence of such extensional fault systems trending orthogonal to the trench along the Coastal Cordillera in southern Peru is interpreted to reflect a strong coupling between the two plates. In this particular case, stress transfer to the upper plate, at least along the coastal fringe, appears to have induced crustal seismic events that were initiated mainly during and after the 2001 earthquake. The seafloor roughness of the subducting plate is usually thought to be a cause of segmentation along subduction zones. However, after comparing and discussing the role of inherited structures within the upper plate to the subduction zone segmentation in southern Peru, we suggest that the continental structure itself may exert some feedback control on the segmentation of the subduction zone and thus participate to define the rupture pattern of major subduction earthquakes along the southern Peru continental margin.

  1. Cardiac activation mapping using ultrasound current source density imaging (UCSDI).

    Science.gov (United States)

    Olafsson, Ragnar; Witte, Russell S; Jia, Congxian; Huang, Sheng-Wen; Kim, Kang; O'Donnell, Matthew

    2009-03-01

    We describe the first mapping of biological current in a live heart using ultrasound current source density imaging (UCSDI). Ablation procedures that treat severe heart arrhythmias require detailed maps of the cardiac activation wave. The conventional procedure is time-consuming and limited by its poor spatial resolution (5-10 mm). UCSDI can potentially improve on existing mapping procedures. It is based on a pressure-induced change in resistivity known as the acousto-electric (AE) effect, which is spatially confined to the ultrasound focus. Data from 2 experiments are presented. A 540 kHz ultrasonic transducer (f/# = 1, focal length = 90 mm, pulse repetition frequency = 1600 Hz) was scanned over an isolated rabbit heart perfused with an excitation-contraction decoupler to reduce motion significantly while retaining electric function. Tungsten electrodes inserted in the left ventricle recorded simultaneously the AE signal and the low-frequency electrocardiogram (ECG). UCSDI displayed spatial and temporal patterns consistent with the spreading activation wave. The propagation velocity estimated from UCSDI was 0.25 +/- 0.05 mm/ms, comparable to the values obtained with the ECG signals. The maximum AE signal-to-noise ratio after filtering was 18 dB, with an equivalent detection threshold of 0.1 mA/ cm(2). This study demonstrates that UCSDI is a potentially powerful technique for mapping current flow and biopotentials in the heart.

  2. Improved Active Harmonic Current Elimination Based on Voltage Detection.

    Directory of Open Access Journals (Sweden)

    Tianyuan Tan

    Full Text Available With the increasing penetration of power electronic equipment in modern residential distribution systems, harmonics mitigation through the distributed generation (DG interfacing converters has received significant attention. Among recently proposed methods, the so-called active resonance damper (ARD and harmonic voltage compensator (HVC based on voltage detection can effectively reduce the harmonic distortions in selected areas of distribution systems. However, it is found out that when traditional ARD algorithm is used to eliminate harmonic current injected by non-linear loads, its performance is constrained by stability problems and can at most eliminate half of the load harmonic currents. Thus, inspired by the duality between ARD and HVC, this paper presents a novel improved resistive active power filter (R-APF algorithm based on integral-decoupling control. The design guideline for its parameters is then investigated through carefully analyzing the closed-loop poles' trajectory. Computer studies demonstrate that the proposed algorithm can effectively mitigate the load harmonic currents and its performance is much better than traditional ARD based on proportional control.

  3. Adaptive Current Control Method for Hybrid Active Power Filter

    Science.gov (United States)

    Chau, Minh Thuyen

    2016-09-01

    This paper proposes an adaptive current control method for Hybrid Active Power Filter (HAPF). It consists of a fuzzy-neural controller, identification and prediction model and cost function. The fuzzy-neural controller parameters are adjusted according to the cost function minimum criteria. For this reason, the proposed control method has a capability on-line control clings to variation of the load harmonic currents. Compared to the single fuzzy logic control method, the proposed control method shows the advantages of better dynamic response, compensation error in steady-state is smaller, able to online control is better and harmonics cancelling is more effective. Simulation and experimental results have demonstrated the effectiveness of the proposed control method.

  4. The mapping methods and division of tectonic units of the regional tectonic map in the eastern China seas and adjacent regions

    Institute of Scientific and Technical Information of China (English)

    YIN Yanhong; ZHANG Xunhua; WEN Zhenhe; GUO Zhenxuan

    2009-01-01

    The geological-geophysical map series of the eastern China seas and adjacent region (1:1 000 000) will be published in the late half year of 2009. The regional tectonic map is one of the main professional maps. The Mapping methods, the division method of geological tectonic units and the main geological tectonic units are mainly discussed. The strata from Pliocene to Holocene are peeled off so as to display the Pre-Pliocene structures. In basins, isopaches are drawn for the Cenozoic deposits. The plate tectonic theory and present tectonic pattern are adopted as the priorities in tectonic division. As to the division of intraplate tectonic units, it is a revision, complement and improvement of previous dividing systems, and the nomenclature for each tectonic unit follows the current system in China. The first-order tectonic unit is plate (Pacific Plate, Eurasian Plate and Philippine Sea Plate). The second-order tectonic unit is tectonic domain (East Asian continental tectonic domain,East Asian continental margin tectonic domain and west Pacific tectonic domain). The Philippine Sea Plate and the west part of the Pacific Plate are called the West Pacific tectonic domain. The part of the Eurasian Plate involved in this study area can be further divided into East Asian continental tectonic domain and East Asian continental margin tectonic domain. The East Asian continental margin domain is composed of the Ryukyu island arc, the Okinawa Trough back-arc basin and the back-arc basin of Sea of Japan. The East Asian continental tectonic domain in this study area is composed of the Sino-Korea Massif, the Changjiang River (Yangtze) Massif and South China Massif. In turn, these massifs consist of basins, folded belts or uplift zones. The basins,the folded belts or the uplift zones are further divided into uplifts and depressions made up of sags and swells.

  5. The effect of Peltier heat during current activated densification

    Science.gov (United States)

    Becker, A.; Angst, S.; Schmitz, A.; Engenhorst, M.; Stoetzel, J.; Gautam, D.; Wiggers, H.; Wolf, D. E.; Schierning, G.; Schmechel, R.

    2012-07-01

    It is shown that current-activated pressure-assisted densification (CAPAD) is sensitive to the Peltier effect. Under CAPAD, the Peltier effect leads to a significant redistribution of heat within the sample during the densification. The densification of highly p-doped silicon nanoparticles during CAPAD and the properties of the obtained samples are investigated experimentally and by computer simulation. Both, simulation and experiments, indicate clearly a higher temperature on the cathode side and a decreasing temperature from the center to the outer shell. Furthermore, computer simulations provide additional insights into the temperature profile which explain the anisotropic properties of the measured sample.

  6. Data Mining Activities for Bone Discipline - Current Status

    Science.gov (United States)

    Sibonga, J. D.; Pietrzyk, R. A.; Johnston, S. L.; Arnaud, S. B.

    2008-01-01

    The disciplinary goals of the Human Research Program are broadly discussed. There is a critical need to identify gaps in the evidence that would substantiate a skeletal health risk during and after spaceflight missions. As a result, data mining activities will be engaged to gather reviews of medical data and flight analog data and to propose additional measures and specific analyses. Several studies are briefly reviewed which have topics that partially address these gaps in knowledge, including bone strength recovery with recovery of bone mass density, current renal stone formation knowledge, herniated discs, and a review of bed rest studies conducted at Ames Human Research Facility.

  7. Active tectonics in the NW-German Basin: Evidence from correlations between the modern landscape and deep geological structures (Lower Saxony, river Hunte)

    Science.gov (United States)

    Szeder, T.; Sirocko, F.

    2003-04-01

    The catchment basin of the river Hunte (NW-German Basin, Lower Saxony) was studied on a mesoscale (length of ˜90 km) to investigate if tectonic movements in the upper crust influence modern landscape formation. Crustal movements led to upwarping of the Lower Weichselian Terrace above the transition zone of a major crustal boundery of the NW-German Basin (Lower Saxony Basin/Pompeckj Block) with an average vertical velocity of about 0,5 mm/a over the last 12 ka. The Lower Weichselian Terrace and the Hunte catchment basin are narrowest at the same position. Even the Holocene Alluvial Plain is affected by active tectonics. The Holocene Alluvial Plain is narrower and shows a negative gradient directly above a deep seated Permian salt pillow which can be traced over a vertical distance of about 4000 m as an anticline structure to the uppermost Tertiary (100 m b.s.l.). The spatial similarity of fluvial anomalies with anomalies of the geological subground indicates that crustal movements still exercise control on fluvial dynamics and are coupled to the geological predesign. Basin subsidence is thought to have triggered primarily the aggradation of the Lower Weichselian Terrace, because there is an accordance between the mean recent velocity of basin subsidence (˜-0,21 mm/a), calculated from repeated geodetic fine levelling and the mean sedimentation rate of the Lower Weichselian Terrace (˜0,2--0,4 mm/a). In addition, sedimentation rates of the Lower Weichselian Terrace were nearly constant over a time span of about 35 ka (˜47--12 ka BP). During these times the climate has changed rapidly over Northern Europe (Dansgaard-Oeschger Cycles) which affected river morphology, hydrology and sediment supply. However, the observation that no change of the mean sedimentation rate is observable indicates a long term subsiding tendency which enables accumulation of longer fluvial sequences independent of short scale climatic fluctuations. Most likely northward tilting of the NW

  8. Tectonic interpretation of the 13 february 2001, mw 6.6, El Salvador Earthquake: New evidences of coseismic surface rupture and paleoseismic activity.

    Science.gov (United States)

    Martinez-Diaz, J. J.; Canora, C.; Villamor, P.; Capote, R.; Alvarez-Gomez, J. A.; Berryman, K.; Bejar, M.; Tsige, M.

    2009-04-01

    In February 2001 a major strike slip earthquake stroke the central part of El Salvador causing hundreds of people killed, thousands injured and extensive damage. After this event the scientific effort was mainly focused on the study of the enormous and catastrophic landslides triggered by this event and no evidences of surface faulting were detected. This earthquake was produced by the reactivation of the Ilopango-San Vicente segment of the El Salvador Fault Zone. Recently, a surface rupture displacement on the ground was identified. The analysis of aerial and field photographs taken few hours after the event and the mapping of the conserved ground structures shows a pure strike-slip displacement ranging from 20 to 50 cm, with secondary features indicating dextral shearing. The paleoseismic analysis made through the excavation of six trenches and Radiocarbon dating indicate a minimum slip rate of 2.0 mm/yr and a recurrence of major ruptures (Mw > 6.5) lower than 500 yr. These evidences give interesting local data to increase our understanding about the tectonic behavior and the way how active deformation develops along the northern limit of the forearc sliver related to the Centroamerican subduction area.

  9. Seismic activity at the Cerro Prieto Geothermal Area (Mexico) from August 1994 to December 1995, and its relationship with tectonics and fluid exploitation

    Science.gov (United States)

    Fabriol, H.; Munguía, L.

    A continuous monitoring of the Cerro Prieto geothermal field was carried out from August 1994 to December 1995 to investigate the seismicity of tectonic origin and the seismicity triggered by exploitation activities. Hypocenters for 148 events were located mainly around the northern end of the Cerro Prieto fault and within the geothermal zone. The estimated focal depths range mostly from 1 to 6 km, for earthquakes with magnitudes from 0.5 to 4.6. It was difficult to distinguish between natural and triggered seismicity. We observed a single case of an earthquake for which a correlation in time and space seems plausible with a sharp increase of fluid injection in a well located at less than 1 km from the epicenter. Fault plane solutions of 26 events with magnitudes between 2.8 and 4.6 indicate right-lateral strike-slip motion for earthquakes that occur near the Cerro Prieto and Imperial faults. Inside the geothermal zone, events with normal components of motion were recorded, as expected from the extensional stress regime of the pull-apart basin laying between both faults.

  10. Tectonic Theory and Practice

    DEFF Research Database (Denmark)

    Frier, Marie; Fisker, Anna Marie; Kirkegaard, Poul Henning

    2010-01-01

    defined by Semper as a constructive precondition, a theory for developing a novel tectonic relation between home and system opens up. As a research result the paper suggests a practical spatial exploitation of the actual prefab construction, defining interiority not solely as a visual occupation......’ is an example of this sensuous interior transformation of a house into a home, a level of detailing which is, however, seldom represented in the prefabricated house. Consequently, this paper investigates whether interiority can be developed as a tectonic theory and design principle for uniting home and system......Since the first optimistic originally Modernist prefab visions were formulated there has been, and are still, challenges to be overcome in order to fulfill the increasing need for fast, precise and economically produced homes. The tectonic need to transform a home, into a system of joints...

  11. Aspects of calcium-activated chloride currents: a neuronal perspective.

    Science.gov (United States)

    Scott, R H; Sutton, K G; Griffin, A; Stapleton, S R; Currie, K P

    1995-06-01

    Ca(2+)-activated Cl- channels are expressed in a variety of cell types, including central and peripheral neurones. These channels are activated by a rise in intracellular Ca2+ close to the cell membrane. This can be evoked by cellular events such as Ca2+ entry through voltage- and ligandgated channels or release of Ca2+ from intracellular stores. Additionally, these Ca(2+)-activated Cl currents (ICl(Ca)) can be activated by raising intracellular Ca2+ through artificial experimental procedures such as intracellular photorelease of Ca2+ from "caged" photolabile compounds (e.g. DM-nitrophen) or by treating cells with Ca2+ ionophores. The potential changes that result from activation of Ca(2+)-activated Cl- channels are dependent on resting membrane potential and the equilibrium potential for Cl-. Ca2+ entry during a single action potential is sufficient to produce substantial after potentials, suggesting that the activity of these Cl- channels can have profound effects on cell excitability. The whole cell ICl(Ca) can be identified by sensitivity to increased Ca2+ buffering capacity of the cell, anion substitution studies and reversal potential measurements, as well as by the actions of Cl- channel blockers. In cultured sensory neurones, there is evidence that the ICl(Ca) deactivates as Ca2+ is buffered or removed from the intracellular environment. To date, there is no evidence in mammalian neurones to suggest these Ca(2+)-sensitive Cl- channels undergo a process of inactivation. Therefore, ICl(Ca) can be used as a physiological index of intracellular Ca2+ close to the cell membrane. The ICl(Ca) has been shown to be activated or prolonged as a result of metabolic stress, as well as by drugs that disturb intracellular Ca2+ homeostatic mechanisms or release Ca2+ from intracellular stores. In addition to sensitivity to classic Cl- channel blockers such as niflumic acid, derivatives of stilbene (4,4'diisothiocyanostilbene-2,2'-disulphonic acid, 4-acetamido-4

  12. Quaternary tectonic activity in NW Jordan: Insights for a new model of transpression-transtension along the southern Dead Sea Transform Fault

    Science.gov (United States)

    Al-Awabdeh, M.; Pérez-Peña, J. V.; Azañón, J. M.; Booth-Rea, G.; Abed, A.; Atallah, M.; Galve, J. P.

    2016-12-01

    The Dead Sea Transform Fault (DSTF) constitutes the transform plate boundary between the African and Arabian plates. The southern part of this fault has been traditionally divided into two main segments, the Wadi Araba Fault (WAF) and the Jordan Valley Fault (JVF), connected through the Dead Sea continental pull-apart basin. Active tectonic studies in NW Jordan have traditionally focused on these DSTF structures and have neglected other prominent structures in the region, such as the Amman Hallabat Structure (AHS) and Shueib Structure (SHS) fault systems, which have been considered inactive since the Cretaceous. However, some recent studies have suggested a possible local reactivation of the southern parts of these structures. In this work, we carried out a detailed geological study of the NE Dead Sea Basin to analyze the Quaternary activity of the AHS and SHS based on field observations and structural analyses. Our findings have revealed that the AHS and SHS structures present clear Quaternary activity and accommodate a small part of the deformation of the southern DSTF. In the Quaternary, the southwestern part of the AHS has acted as the northernmost continuation of the WAF, whereas the SHS has acted as a transfer fault associated with NW-SE normal faults with low to moderate throws (meters to decameters) that connect this structure to the JVF. These NW-SE normal faults constitute the northeastern border of the Dead Sea depression (Jericho Valley). They produce a topographic front and separate the sediments of the Jordan Valley in the hanging wall from the Mesozoic sedimentary sequence located in the footwall.

  13. Identifying active structures in the Kayak Island and Pamplona Zones: Implications for offshore tectonics of the Yakutat Microplate, Gulf of Alaska

    Science.gov (United States)

    Worthington, Lindsay L.; Gulick, Sean P. S.; Pavlis, Terry L.

    Within the northern Gulf of Alaska, the Yakutat (YAK) microplate obliquely collides with and subducts beneath the North American (NA) continent at near-Pacific plate velocities. We investigate the extent that thin-skinned deformation on offshore structures located within the western portion of the unsubducted YAK block accommodates YAK-NA convergence. We compare faulting and folding observed on high-resolution and basin-scale multichannel seismic (MCS) reflection data with earthquake locations and surface ruptures observed on high-resolution bathymetric data. Holocene sediments overlying the Kayak Island fault zone (KIZ), previously interpreted as a region of active contraction, are relatively flat-lying, suggesting that active convergence within the KIZ is waning. Seismic reflection profiles east of KIZ show up to ˜200 m of undisturbed sediments overlying older folds in the Bering Trough, indicating that this area has been tectonically inactive since at least the last ˜1.3 Ma. Farther east, MCS profiles image active deformation in surface sediments along the eastern edge of the Pamplona zone (PZ) fold-and-thrust belt, that are collocated with a concentration of earthquake events that continues southwest to Khitrov Ridge and onshore through Icy Bay. These observations suggest that during the late Quaternary offshore shallow deformation style changed from distributed across the western Yakutat block to localized at the eastern edge of the PZ with extrusion of sediments southwest through the Khitrov Ridge area to the Aleutian Trench. This shallow deformation is interpreted as deformation of an accretionary complex above a shallow decollement.

  14. Lasting mantle scars lead to perennial plate tectonics.

    Science.gov (United States)

    Heron, Philip J; Pysklywec, Russell N; Stephenson, Randell

    2016-06-10

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a 'perennial' phenomenon.

  15. Lasting mantle scars lead to perennial plate tectonics

    Science.gov (United States)

    Heron, Philip J.; Pysklywec, Russell N.; Stephenson, Randell

    2016-06-01

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a `perennial' phenomenon.

  16. Energy of plate tectonics calculation and projection

    Directory of Open Access Journals (Sweden)

    N. H. Swedan

    2013-02-01

    Full Text Available Mathematics and observations suggest that the energy of the geological activities resulting from plate tectonics is equal to the latent heat of melting, calculated at mantle's pressure, of the new ocean crust created at midocean ridges following sea floor spreading. This energy varies with the temperature of ocean floor, which is correlated with surface temperature. The objective of this manuscript is to calculate the force that drives plate tectonics, estimate the energy released, verify the calculations based on experiments and observations, and project the increase of geological activities with surface temperature rise caused by climate change.

  17. Identifying active interplate and intraplate fault zones in the western Caribbean plate from seismic reflection data and the significance of the Pedro Bank fault zone in the tectonic history of the Nicaraguan Rise

    Science.gov (United States)

    Ott, B.; Mann, P.

    2015-12-01

    The offshore Nicaraguan Rise in the western Caribbean Sea is an approximately 500,000 km2 area of Precambrian to Late Cretaceous tectonic terranes that have been assembled during the Late Cretaceous formation of the Caribbean plate and include: 1) the Chortis block, a continental fragment; 2) the Great Arc of the Caribbean, a deformed Cretaceous arc, and 3) the Caribbean large igneous province formed in late Cretaceous time. Middle Eocene to Recent eastward motion of the Caribbean plate has been largely controlled by strike-slip faulting along the northern Caribbean plate boundary zone that bounds the northern margin of the Nicaraguan Rise. These faults reactivate older rift structures near the island of Jamaica and form the transtensional basins of the Honduran Borderlands near Honduras. Recent GPS studies suggest that small amount of intraplate motion within the current margin of error of GPS measurements (1-3 mm/yr) may occur within the center of the western Caribbean plate at the Pedro Bank fault zone and Hess Escarpment. This study uses a database of over 54,000 km of modern and vintage 2D seismic data, combined with earthquake data and results from previous GPS studies to define the active areas of inter- and intraplate fault zones in the western Caribbean. Intraplate deformation occurs along the 700-km-long Pedro Bank fault zone that traverses the center of the Nicaraguan Rise and reactivates the paleo suture zone between the Great Arc of the Caribbean and the Caribbean large igneous province. The Pedro Bank fault zone also drives active extension at the 200-km-long San Andres rift along the southwest margin of the Nicaraguan Rise. Influence of the Cocos Ridge indentor may be contributing to reactivation of faulting along the southwesternmost, active segment of the Hess Escarpment.

  18. Physico-chemical evolution of groundwater in tectonically active areas. Application to the Leana hot spring (Murcia Region, SE Spain)

    Science.gov (United States)

    Martínez, M.; Hornero, J.; Trujillo, C.

    2016-09-01

    Seismic events can affect the physico-chemical characteristics of groundwater. These anomalies are of a pre-seismic, co-seismic and post-seismic nature and correspond to pulse variations, sudden increases and decreases without return to initial values and upward or downward changes in trend. Continuous and in situ conductivity and temperature monitoring and periodic water sampling at a hot spring associated with neotectonic activity are of great interest for establishing predictive methods. This method is limited to the seismic activity affecting the fracturing system with which the hot spring is associated. The Region of Murcia and surroundings (southeast Spain) was selected as the study area for exploring the nature of these influences on groundwater. A hot spring in the Leana spa (Murcia) was equipped and monitored during the period 2006-2008, allowing for the in situ determination of conductivity and temperature as well as of major and minor constituents at the laboratory. Due to its proximity and related with fault network, we suggest that 86 % of earthquakes located between 0 and 10 km may affect in situ parameters of groundwater, and 75 % may affect laboratory determinations. This percentage drops in more distant zones. Of all earthquakes that seem to influence groundwater, 55 % of the in situ parameter anomalies and 53 % of laboratory were of a pre-seismic nature.

  19. Active tectonics of the Calabrian subduction revealed by new multi-beam bathymetric data and high-resolution seismic profiles in the Ionian Sea (Central Mediterranean)

    Science.gov (United States)

    Gutscher, Marc-André; Kopp, Heidrun; Krastel, Sebastian; Bohrmann, Gerhard; Garlan, Thierry; Zaragosi, Sebastien; Klaucke, Ingo; Wintersteller, Paul; Loubrieu, Benoit; Le Faou, Yann; San Pedro, Laurine; Dominguez, Stephane; Rovere, Marzia; Mercier de Lepinay, Bernard; Ranero, Cesar; Sallares, Valenti

    2017-03-01

    The detailed morphology and internal structure of the Calabrian accretionary wedge and adjacent Eastern Sicily margin are imaged in unprecedented detail by a combined dataset of multi-beam bathymetry and high-resolution seismic profiles. The bathymetric data represent the results of 6 recent marine geophysical surveys since 2010 as well as a compilation of earlier surveys presented as a 2 arc-sec (60 m) grid. Several distinct morpho-tectonic provinces are identified including: the deeply incised Malta-Hyblean Escarpment, numerous submarine canyons, broad regions of relatively flat seafloor dominated by fields of sediment waves, the gently undulating anticlinal fold-and-thrust belts of the external Calabrian accretionary wedge and the adjacent portion of the Western Mediterranean Ridge. The Calabrian arc can be divided into 4 domains (from SE to NW): 1) the undeformed Ionian abyssal plain, 2) the external evaporitic wedge, 3) the internal clastic wedge, 4) the Calabrian backstop (Variscan crystalline basement). The Calabrian accretionary wedge can also be divided laterally into two major lobes, the NE- and the SW lobes, and two minor lobes. The kinematics of the limit between the two major lobes is investigated and shown to be sinistral in the external (evaporitic) wedge. A network of radial slip lines within the southernmost external wedge unequivocally demonstrate ongoing dextral displacement of a rigid indenter (representing the corner of the clastic wedge) into the evaporitic wedge thereby confirming the geodynamic model of an active lateral slab tear fault here off eastern Sicily. The slab tear produces a series of major sub-parallel dextral strike-slip faults offshore Mt. Etna and south of the Straits of Messina consistent with the relative motions between Calabria and the Peloritan domain (NE Sicily). Abundant strike-slip faulting, and wide-spread folding and thrusting observed throughout the entire accretionary wedge, indicate regional shortening between the

  20. Late Pleistocene to Holocene sedimentation and hydrocarbon seeps on the continental shelf of a steep, tectonically active margin, southern California, USA

    Science.gov (United States)

    Draut, Amy E.; Hart, Patrick E.; Lorenson, T.D.; Ryan, Holly F.; Wong, Florence L.; Sliter, Ray W.; Conrad, James E.

    2009-01-01

    Small, steep, uplifting coastal watersheds are prolific sediment producers that contribute significantly to the global marine sediment budget. This study illustrates how sedimentation evolves in one such system where the continental shelf is largely sediment-starved, with most terrestrial sediment bypassing the shelf in favor of deposition in deeper basins. The Santa Barbara-Ventura coast of southern California, USA, is considered a classic area for the study of active tectonics and of Tertiary and Quaternary climatic evolution, interpretations of which depend upon an understanding of sedimentation patterns. High-resolution seismic-reflection data over >570 km2 of this shelf show that sediment production is concentrated in a few drainage basins, with the Ventura and Santa Clara River deltas containing most of the upper Pleistocene to Holocene sediment on the shelf. Away from those deltas, the major factor controlling shelf sedimentation is the interaction of wave energy with coastline geometry. Depocenters containing sediment 5-20 m thick exist opposite broad coastal embayments, whereas relict material (bedrock below a regional unconformity) is exposed at the sea floor in areas of the shelf opposite coastal headlands. Locally, natural hydrocarbon seeps interact with sediment deposition either to produce elevated tar-and-sediment mounds or as gas plumes that hinder sediment settling. As much as 80% of fluvial sediment delivered by the Ventura and Santa Clara Rivers is transported off the shelf (some into the Santa Barbara Basin and some into the Santa Monica Basin via Hueneme Canyon), leaving a shelf with relatively little recent sediment accumulation. Understanding factors that control large-scale sediment dispersal along a rapidly uplifting coast that produces substantial quantities of sediment has implications for interpreting the ancient stratigraphic record of active and transform continental margins, and for inferring the distribution of hydrocarbon resources

  1. Current activities handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-02-27

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the activities each of the thirteen state legislatures potentially affected by the Formerly Utilized Sites Remedial Action Program. It contains a description of the state legislative procedural rules and a schedule of each legislative session; a summary of pending relevant legislation; the name and telephone number of legislative and state agency contacts; and the full text of all bills identified.

  2. Current Reactor Physics Benchmark Activities at the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess; Margaret A. Marshall; Mackenzie L. Gorham; Joseph Christensen; James C. Turnbull; Kim Clark

    2011-11-01

    The International Reactor Physics Experiment Evaluation Project (IRPhEP) [1] and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) [2] were established to preserve integral reactor physics and criticality experiment data for present and future research. These valuable assets provide the basis for recording, developing, and validating our integral nuclear data, and experimental and computational methods. These projects are managed through the Idaho National Laboratory (INL) and the Organisation for Economic Co-operation and Development Nuclear Energy Agency (OECD-NEA). Staff and students at the Department of Energy - Idaho (DOE-ID) and INL are engaged in the development of benchmarks to support ongoing research activities. These benchmarks include reactors or assemblies that support Next Generation Nuclear Plant (NGNP) research, space nuclear Fission Surface Power System (FSPS) design validation, and currently operational facilities in Southeastern Idaho.

  3. Using earthquake-triggered landslides as a hillslope-scale shear strength test: Insights into rock strength properties at geomorphically relevant spatial scales in high-relief, tectonically active settings

    Science.gov (United States)

    Gallen, Sean; Clark, Marin; Godt, Jonathan; Lowe, Katherine

    2016-04-01

    The material strength of rock is known to be a fundamental property in setting landscape form and geomorphic process rates as it acts to modulate feedbacks between earth surface processes, tectonics, and climate. Despite the long recognition of its importance in landscape evolution, a quantitative understanding of the role of rock strength in affecting geomorphic processes lags our knowledge of the influence of tectonics and climate. This gap stems largely from the fact that it remains challenging to quantify rock strength at the hillslope scale. Rock strength is strongly scale dependent because the number, size, spacing, and aperture of fractures sets the upper limit on rock strength, making it difficult to extrapolate laboratory measurements to landscape-scale interpretations. Here we present a method to determine near-surface rock strength at the hillslope-scale, relying on earthquake-triggered landslides as a regional-scale "shear strength" test. We define near-surface strength as the average strength of rock sample by the landslides, which is typically present results from two well-documented case-studies of earthquakes that caused widespread mass-wasting; the 2008 Mw 7.9 Wenchuan Earthquake, Sichuan Province, China and the 1994 Mw. 6.8 Northridge Earthquake, CA, USA. We show how this model can be used to determine near-surface rock strength and reproduce mapped landslide patterns provided the spatial distribution of local hillslope gradient, earthquake peak ground acceleration (PGA), and coseismic landsliding are well constrained. Results suggest that near-surface rock strength in these tectonically active settings is much lower than that obtained using typical laboratory shear strength measurements on intact rock samples. Furthermore, the near-surface material strength is similar between the study areas despite differences in tectonic, climatic, and lithologic conditions. Variations in near-surface strength within each setting appear to be more strongly

  4. Deep electrical resistivity tomography along the tectonically active Middle Aterno Valley (2009 L'Aquila earthquake area, central Italy)

    Science.gov (United States)

    Pucci, Stefano; Civico, Riccardo; Villani, Fabio; Ricci, Tullio; Delcher, Eric; Finizola, Anthony; Sapia, Vincenzo; De Martini, Paolo Marco; Pantosti, Daniela; Barde-Cabusson, Stéphanie; Brothelande, Elodie; Gusset, Rachel; Mezon, Cécile; Orefice, Simone; Peltier, Aline; Poret, Matthieu; Torres, Liliana; Suski, Barbara

    2016-11-01

    Three 2-D Deep Electrical Resistivity Tomography (ERT) transects, up to 6.36 km long, were obtained across the Paganica-San Demetrio Basin, bounded by the 2009 L'Aquila Mw 6.1 normal-faulting earthquake causative fault (central Italy). The investigations allowed defining for the first time the shallow subsurface basin structure. The resistivity images, and their geological interpretation, show a dissected Mesozoic-Tertiary substratum buried under continental infill of mainly Quaternary age due to the long-term activity of the Paganica-San Demetrio normal faults system (PSDFS), ruling the most recent deformational phase. Our results indicate that the basin bottom deepens up to 600 m moving to the south, with the continental infill largely exceeding the known thickness of the Quaternary sequence. The causes of this increasing thickness can be: (1) the onset of the continental deposition in the southern sector took place before the Quaternary, (2) there was an early stage of the basin development driven by different fault systems that produced a depocentre in the southern sector not related to the present-day basin shape, or (3) the fault system slip rate in the southern sector was faster than in the northern sector. We were able to gain sights into the long-term PSDFS behaviour and evolution, by comparing throw rates at different timescales and discriminating the splays that lead deformation. Some fault splays exhibit large cumulative throws (>300 m) in coincidence with large displacement of the continental deposits sequence (>100 m), thus testifying a general persistence in time of their activity as leading splays of the fault system. We evaluate the long-term (3-2.5 Myr) cumulative and Quaternary throw rates of most of the leading splays to be 0.08-0.17 mm yr-1, indicating a substantial stability of the faults activity. Among them, an individual leading fault splay extends from Paganica to San Demetrio ne' Vestini as a result of a post-Early Pleistocene linkage of

  5. Tiber delta CO2-CH4 degassing: A possible hybrid, tectonically active Sediment-Hosted Geothermal System near Rome

    Science.gov (United States)

    Ciotoli, G.; Etiope, G.; Marra, F.; Florindo, F.; Giraudi, C.; Ruggiero, L.

    2016-01-01

    Fiumicino town in the Tiber River delta, near Rome International Airport (Italy), is historically affected by large amounts of carbon dioxide (CO2) in the ground and gas eruptions triggered by shallow drilling. While it is known that CO2 originates from carbonate thermometamorphism and/or mantle degassing, the origin of methane (CH4) associated with CO2 is uncertain and the outgassing spatial distribution is unknown. Combining isotope gas geochemistry, soil gas, and structural-stratigraphic analyses, we provide evidence for a hybrid fluid source system, classifiable as Sediment-Hosted Geothermal System (SHGS), where biotic CH4 from sedimentary rocks is carried by deep geothermic CO2 through active segments of a half-graben. Molecular and isotopic composition of CH4 and concentration of heavier alkanes (ethane and propane), obtained from gas vents and soil gas throughout the delta area, reveal that thermogenic CH4 (up to 3.7 vol% in soil gas; δ13CCH4: -37 to -40‰ VPDB-Vienna Peedee Belemnite, and δ2HCH4: -162 to -203‰ VSMOW - Vienna Standard Mean Ocean Water in gas vents) prevails over possible microbial and abiotic components. The hydrocarbons likely result from known Meso-Cenozoic petroleum systems of the Latium Tyrrhenian coast. Overmaturation of source rocks or molecular fractionation induced by gas migration are likely responsible for increased C1/C2+ ratios. CO2 and CH4 soil gas anomalies are scattered along NW-SE and W-E alignments, which, based on borehole, geomorphologic, and structural-stratigraphic analyses, coincide with active faults of a half-graben that seems to have controlled the recent evolution of the Tiber delta. This SHGS can be a source of considerable greenhouse gas emissions to the atmosphere and hazards for humans and buildings.

  6. Tectonic vision in architecture

    DEFF Research Database (Denmark)

    Beim, Anne

    1999-01-01

    By introducing the concept; Tectonic Visions, The Dissertation discusses the interrelationship between the basic idea, the form principles, the choice of building technology and constructive structures within a given building. Includes Mies van der Rohe, Le Corbusier, Eames, Jorn Utzon, Louis Kahn...

  7. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  8. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  9. Advances in Structural Geology and Tectonics in the Late 20th Century: A Review

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on analyses of the share of documents of structural geology and tectonics in the GeoRef system over 100 years in the last century, and the historical change of international (31 years) and domestic (16 years) document counts of various topics in structural geology and tectonics, the position of structural geology and tectonics in the geosciences is evaluated and the major advaces in fields of plate tectonics, continental dynamics and global dynamics are reviewed. Our attention mainly focuses on the advances in studies of structural analysis, deformation mechanisms and rheology of rocks,contractional tectonics and late- and post-orogenic extensional collapse in orogens, large-scale strikeslip faults and indentation-extrusion tectonics, active tectonics and natural hazards. The relationships of structural geology and tectonics with petrology and geochronology are also discussed in terms of intersection of scientific disciplines. Finally, some suggestions are proposed for the further development of structural geology and tectonics in China.

  10. Seismic source study of the Racha-Dzhava (Georgia) earthquake from aftershocks and broad-band teleseismic body-wave records: An example of active nappe tectonics

    Science.gov (United States)

    Fuenzalida, H.; Rivera, L.; Haessler, H.; Legrand, D.; Philip, H.; Dorbath, L.; McCormack, D.; Arefiev, S.; Langer, C.; Cisternas, A.

    1997-01-01

    The Racha-Dzhava earthquake (Ms = 7.0) that occurred on 1991 April 29 at 09:12:48.1 GMT in the southern border of the Great Caucasus is the biggest event ever recorded in the region, stronger than the Spitak earthquake (Ms = 6.9) of 1988. A field expedition to the epicentral area was organised and a temporary seismic network of 37 stations was deployed to record the aftershock activity. A very precise image of the aftershock distribution is obtained, showing an elongated cloud oriented N105??, with one branch trending N310?? in the western part. The southernmost part extends over 80 km, with the depth ranging from 0 to 15 km, and dips north. The northern branch, which is about 30 km long, shows activity that ranges in depth from 5 to 15 km. The complex thrust dips northwards. A stress-tensor inversion from P-wave first-motion polarities shows a state of triaxial compression, with the major principal axis oriented roughly N-S, the minor principal axis being vertical. Body-waveform inversion of teleseismic seismograms was performed for the main shock, which can be divided into four subevents with a total rupture-time duration of 22 s. The most important part of the seismic moment was released by a gentle northerly dipping thrust. The model is consistent with the compressive tectonics of the region and is in agreement with the aftershock distribution and the stress tensor deduced from the aftershocks. The focal mechanisms of the three largest aftershocks were also inverted from body-wave records. The April 29th (Ms = 6.1) and May 5th (Ms = 5.4) aftershocks have thrust mechanisms on roughly E-W-oriented planes, similar to the main shock. Surprisingly, the June 15th (Ms = 6.2) aftershock shows a thrust fault striking N-S. This mechanism is explained by the structural control of the rupture along the east-dipping geometry of the Dzirula Massif close to the Borzhomi-Kazbeg strike-slip fault. In fact, the orientation and shape of the stress tensor produce a thrust on a N

  11. Active tectonic structures and submarine landslides offshore southern Apulia (Italy): a new scenario for the 1743 earthquake and subsequent tsunami

    Science.gov (United States)

    Milia, Alfonsa; Iannace, Pietro; Torrente, Maurizio M.

    2017-06-01

    The southern Apulia foreland recorded a strong (Imax=X MCS) earthquake in 1743 and a concomitant tsunami, which struck the southeastern Salento coast. The seismo-genetic fault and the triggering factors of the tsunami are unknown. Three-dimensional interpretation of multichannel seismic profiles calibrated by wells using a GIS software enabled the recognition of the stratigraphic succession, structural framework, and submarine landslides offshore Salento. A thin Pliocene unit overlying the Mesozoic-Cenozoic substrate is covered by a Pleistocene succession separated by a Middle Pleistocene unconformity that formed during the regional uplift of Salento. The latter gave rise to the morphologic conditions for the deposition of a prograding wedge off the Salento coast, with a shelf break located at 150 m depth. Normal faults, mainly oriented NW-SE, displaced the early Lower Pleistocene succession and are buried by younger deposits. Since the Middle Pleistocene, a compressional event gave rise to the Apulia uplift and large folds and basement-involved reverse faults that are active in the eastern part of Apulia. A huge (58 km3) slump affecting the Middle Pleistocene prograding wedge has been documented offshore the southeast coast of Salento. The proposed geological scenario of the 1743 earthquake and subsequent tsunami is (1) an initial strong earthquake (Imax=X MCS) associated with a thrust fault located in the eastern sector of the Apulia offshore, (2) a shacking-induced large-volume slump offshore Otranto, and (3) landslide-triggered tsunamis that struck the Salento coast.

  12. Active tectonic structures and submarine landslides offshore southern Apulia (Italy): a new scenario for the 1743 earthquake and subsequent tsunami

    Science.gov (United States)

    Milia, Alfonsa; Iannace, Pietro; Torrente, Maurizio M.

    2017-01-01

    The southern Apulia foreland recorded a strong (Imax=X MCS) earthquake in 1743 and a concomitant tsunami, which struck the southeastern Salento coast. The seismo-genetic fault and the triggering factors of the tsunami are unknown. Three-dimensional interpretation of multichannel seismic profiles calibrated by wells using a GIS software enabled the recognition of the stratigraphic succession, structural framework, and submarine landslides offshore Salento. A thin Pliocene unit overlying the Mesozoic-Cenozoic substrate is covered by a Pleistocene succession separated by a Middle Pleistocene unconformity that formed during the regional uplift of Salento. The latter gave rise to the morphologic conditions for the deposition of a prograding wedge off the Salento coast, with a shelf break located at 150 m depth. Normal faults, mainly oriented NW-SE, displaced the early Lower Pleistocene succession and are buried by younger deposits. Since the Middle Pleistocene, a compressional event gave rise to the Apulia uplift and large folds and basement-involved reverse faults that are active in the eastern part of Apulia. A huge (58 km3) slump affecting the Middle Pleistocene prograding wedge has been documented offshore the southeast coast of Salento. The proposed geological scenario of the 1743 earthquake and subsequent tsunami is (1) an initial strong earthquake (Imax=X MCS) associated with a thrust fault located in the eastern sector of the Apulia offshore, (2) a shacking-induced large-volume slump offshore Otranto, and (3) landslide-triggered tsunamis that struck the Salento coast.

  13. Plate Tectonics: A Framework for Understanding Our Living Planet.

    Science.gov (United States)

    Achache, Jose

    1987-01-01

    Discusses some of the events leading to the development of the theory of plate tectonics. Describes how seismic, volcanic, and tectonic features observed at the surface of the planet are now seen as a consequence of intense internal activity, and makes suggestions about their further investigation. (TW)

  14. Post-seismic erosional characteristics of the Chiufenershan landslide : Implications for erosion process of tectonically active mountains

    Science.gov (United States)

    Chan, Yu-Chang; Lu, Chiao-Yin; Chang, Kou-Jen; Chen, Rou-Fei

    2010-05-01

    The island of Taiwan is resulted from the collision between the Philippine sea plate and the Eurasian plate. The subtropical climate and averaging four typhoons annually, combined with frequent earthquakes, influence much of the Taiwan region. Due to the factors above, not only the active orogeny of Taiwan causes the high uplift rate at about 4 mm/yr, but also drive amazing erosion rate of about 3~6 mm/yr. Previous study indicated approximately 1.9% of global suspended sediment is derived from the small island of Taiwan, which is only about 0.024% of Earth's subaerial surface. Furthermore, modern erosion rates are strongly influenced by large earthquakes and typhoons, and the sediment fluxes after the Mw 7.6 Chi-Chi earthquake of Taiwan are much higher than those before the earthquake. Here we study the Chiufenerhshan landslide, which is one of the large landslides triggered by the Chi-Chi earthquake in the central Taiwan. The avalanche transported a mass of sedimentary rock about 60 m thick and 1.5 km long. Based on the high-resolution topographic data sets from LiDAR or photogrammetry at various years and rain fall data, we have reached the following conclusions: In the period of 8.5 years after the Chi-Chi earthquake, almost 4.2% of the landslide deposits were transported out of the landslide system. Comparing with the mean annual erosion rate of 3~6 mm/yr in Taiwan, the sediment brought out of Chiufenerhshan landslide area is 89.4 mm/yr, a significant amount contributed by the landslide. The mean sediment discharge from this small system is as large as 0.064% of the sediment discharge from the whole Taiwan annually; while the area is only about 0.005% of Taiwan's subaerial surface. Thus, the landslide process has contributed much more to the surface erosion of the Taiwan mountain than other erosion processes.

  15. Short-lived tectonic switch mechanism for long-term pulses of volcanic activity after mega-thrust earthquakes

    Directory of Open Access Journals (Sweden)

    M. Lupi

    2013-06-01

    Full Text Available Eruptive rates in volcanic arcs increase significantly after mega-thrust earthquakes in subduction zones. Over short to intermediate time periods the link between mega-thrust earthquakes and arc response can be attributed to dynamic triggering processes or static stress changes, but a fundamental mechanism that controls long-term pulses of volcanic activity after mega-thrust earthquakes has not been proposed yet. Using geomechanical, geological, and geophysical arguments, we propose that increased eruption rates over longer timescales are due to the relaxation of the compressional regime that accompanies mega-thrust subduction zone earthquakes. More specifically, the reduction of the horizontal stress σh promotes the occurrence of short-lived strike-slip kinematics rather than reverse faulting in the volcanic arc. The relaxation of the pre-earthquake compressional regime facilitates magma mobilization by providing a short-circuit pathway to shallow depths by significantly increasing the hydraulic properties of the system. The timescale for the onset of strike-slip faulting depends on the degree of shear stress accumulated in the arc during inter-seismic periods, which in turn is connected to the degree of strain-partitioning at convergent margins. We performed Coulomb stress transfer analysis to determine the order of magnitude of the stress perturbations in present-day volcanic arcs in response to five actual mega-thrust earthquakes; the 2005 M8.6, 2007 M8.5, and 2007 M7.9 Sumatra earthquakes; the 2010 M8.8 Maule, Chile earthquake; and the 2011 M9.0 Tohoku, Japan earthquake. We find that all, but one, the shallow earthquakes that occurred in the arcs of Sumatra, Chile and Japan show a marked lateral component. Our hypothesis suggests that the long-term response of volcanic arcs to subduction zone mega-thrust earthquakes will be manifested as predominantly strike-slip seismic events, and that these future earthquakes will be followed closely by

  16. Deep reaching versus vertically restricted Quaternary normal faults: Implications on seismic potential assessment in tectonically active regions: Lessons from the middle Aterno valley fault system, central Italy

    Science.gov (United States)

    Falcucci, E.; Gori, S.; Moro, M.; Fubelli, G.; Saroli, M.; Chiarabba, C.; Galadini, F.

    2015-05-01

    We investigate the Middle Aterno Valley fault system (MAVF), a poorly investigated seismic gap in the central Apennines, adjacent to the 2009 L'Aquila earthquake epicentral area. Geological and paleoseismological analyses revealed that the MAVF evolved through hanging wall splay nucleation, its main segment moving at 0.23-0.34 mm/year since the Middle Pleistocene; the penultimate activation event occurred between 5388-5310 B.C. and 1934-1744 B.C., the last event after 2036-1768 B.C. and just before 1st-2nd century AD. These data define hard linkage (sensu Walsh and Watterson, 1991; Peacock et al., 2000; Walsh et al., 2003, and references therein) with the contiguous Subequana Valley fault segment, able to rupture in large magnitude earthquakes (up to 6.8), that did not rupture since about two millennia. By the joint analysis of geological observations and seismological data acquired during to the 2009 seismic sequence, we derive a picture of the complex structural framework of the area comprised between the MAVF, the Paganica fault (the 2009 earthquake causative fault) and the Gran Sasso Range. This sector is affected by a dense array of few-km long, closely and regularly spaced Quaternary normal fault strands, that are considered as branches of the MAVF northern segment. Our analysis reveals that these structures are downdip confined by a decollement represented by to the presently inactive thrust sheet above the Gran Sasso front limiting their seismogenic potential. Our study highlights the advantage of combining Quaternary geological field analysis with high resolution seismological data to fully unravel the structural setting of regions where subsequent tectonic phases took place and where structural interference plays a key role in influencing the seismotectonic context; this has also inevitably implications for accurately assessing seismic hazard of such structurally complex regions.

  17. Tectonic, volcanic and human activity ground deformation signals detected by multitemporal InSAR techniques in the Colima Volcanic Complex (Mexico) rift

    Science.gov (United States)

    Brunori, C.; Norini, G.; Bignami, C.; Groppelli, G.; Zucca, F.; Stramondo, S.; Capra, L.; Cabral-Cano, E.

    2010-12-01

    The evolution of volcanoes is strictly related with their substratum and the regional tectonics. The link among morphology, geology and structure of volcanic edifices and the geological-structural characteristics of the basement is important to understand hazardous phenomena as flank eruptions and lateral collapses of volcanoes. The Colima Rift is an active regional structure, N-S oriented and more than 100 km long and 10 wide. This rift is filled by a ~1 km-thick sequence of quaternary lacustrine sediments, alluvium, and colluvium, mostly underling the about 3000 m thick volcanic pile of the Colima Volcanic Complex (CVC). In addition to the regional structures curved faults, roughly E-W oriented, are observed on the CVC edifice due to the spreading of the volcano moving southward on the weak basement. So in the CVC edifice and surrounding area we can observe the interaction of regional structures and volcanic ones due to the gravitational loading of the volcanic edifice on the weak substratum of the graben. To measure displacements due to magma movement at depth and interaction of regional structures and volcanic ones, SAR interferometry has proven to be a reliable method; however, andesitic stratovolcanoes like the CVC indeed,remain difficult to survey using this technique. The main causes are their specific geometry (steep topography), which induces strong tropospheric artefacts, environmental conditions (e.g., mainly vegetation, ash and/or snow cover), leading to a loss of coherency. In this work we try to detect deformations phenomena for the wide CVC using a robust multitemporal InSAR approach Differential Synthetic Aperture Radar Interferometry (DInSAR). We apply the Hooper (2008) DInSAR algorithm (StamPS/MTI) both to ENVISAT ASARr images acquired from 1993 to 2007 and to ALOS PALSAR (datasets from 2006 to 2010) in order to determine the deformation patterns in the CVC.

  18. WAVE TECTONICS OF THE EARTH

    Directory of Open Access Journals (Sweden)

    Tatiana Yu. Tveretinova

    2015-09-01

    Full Text Available In the Earth's lithosphere, wavy alternation of positive and negative heterochronous structures is revealed; such structures are variable in ranks and separated by vergence zones of fractures and folds. In the vertical profile of the lithosphere, alternating are layers characterized by relatively plastic or fragile rheological properties and distinguished by different states of stress. During the Earth’s evolution, epochs of compression and extension are cyclically repeated, including planetary-scale phenomena which are manifested by fluctuating changes of the planet’s volume. Migration of geological and geophysical (geodynamic processes takes place at the Earth's surface and in its interior. The concept of the wave structure and evolution of the Earth's lithosphere provides explanations to the abovementioned regularities. Wavy nature of tectonic structures of the lithosphere, the cyclic recurrence of migration and geological processes in space and time can be described in terms of the multiple-order wave geodynamics of the Earth's lithosphere that refers to periodical variations of the state of stress. Effects of structure-forming tectonic forces are determined by «interference» of tangential and radial stresses of the Earth. The tangential stresses, which occur primarily due to the rotational regime of the planet, cause transformations of the Earth’s shape, redistributions of its substance in depths, the westward drift of the rock mass in its upper levels, and changes of structural deformation plans. The radial stresses, which are largely impacted by gravity, determine the gravitational differentiation of the substance, vertical flattening and sub-horizontal flow of the rock masses, and associated fold-rupture deformation. Under the uniform momentum geodynamic concept proposed by [Vikulin, Tveritinova, 2004, 2005, 2007, 2008], it is possible to provide consistent descriptions of seismic and volcanic, tectonic and geological processes

  19. Electric-current Neutralization, Magnetic Shear, and Eruptive Activity in Solar Active Regions

    Science.gov (United States)

    Liu, Yang; Sun, Xudong; Török, Tibor; Titov, Viacheslav S.; Leake, James E.

    2017-09-01

    The physical conditions that determine whether or not solar active regions (ARs) produce strong flares and coronal mass ejections (CMEs) are not yet well understood. Here, we investigate the association between electric-current neutralization, magnetic shear along polarity inversion lines (PILs), and eruptive activity in four ARs: two emerging and two well-developed ones. We find that the CME-producing ARs are characterized by a strongly non-neutralized total current, while the total current in the ARs that did not produce CMEs is almost perfectly neutralized. The difference in the PIL shear between these two groups is much less pronounced, which suggests that the degree of current neutralization may serve as a better proxy for assessing the ability of ARs to produce CMEs.

  20. Both barium and calcium activate neuronal potassium currents.

    OpenAIRE

    Ribera, A B; Spitzer, N C

    1987-01-01

    Amphibian spinal neurons in culture possess both rapidly inactivating and sustained calcium-dependent potassium current components, similar to those described for other cells. Divalent cation-dependent whole-cell outward currents were isolated by subtracting the voltage-dependent potassium currents recorded from Xenopus laevis neurons in the presence of impermeant cadmium (100-500 microM) from the currents produced without cadmium but in the presence of permeant divalent cations (50-100 micro...

  1. Preliminary results on the tectonic activity of the Ovacık Fault (Malatya-Ovacık Fault Zone, Turkey): Implications of the morphometric analyses

    Science.gov (United States)

    Yazıcı, Müge; Zabci, Cengiz; Sançar, Taylan; Sunal, Gürsel; Natalin, Boris A.

    2016-04-01

    The Anatolian 'plate' is being extruded westward relative to the Eurasia along two major tectonic structures, the North Anatolian and the East Anatolian shear zones, respectively making its northern and eastern boundaries. Although the main deformation is localized along these two structures, there is remarkable intra-plate deformation within Anatolia, especially which are characterized by NE-striking sinistral and NW-striking dextral strike-slip faults (Şengör et al. 1985). The Malatya-Ovacık Fault Zone (MOFZ) and its northeastern member, the Ovacık Fault (OF), is a one of the NE-striking sinistral strike slip faults in the central 'ova' neotectonic province of Anatolia, located close to its eastern boundary. Although this fault zone is claimed to be an inactive structure in some studies, the recent GPS measurements (Aktuǧ et al., 2013) and microseismic activity (AFAD, 2013) strongly suggest the opposite. In order to understand rates and patterns of vertical ground motions along the OF, we studied the certain morphometric analyses such as hypsometric curves and integrals, longitudinal channel profiles, and asymmetry of drainage basins. The Karasu (Euphrates) and Munzur rivers form the main drainage systems of the study area. We extracted all drainage network from SRTM-based Digital Elevation Model with 30 m ground pixel resolution and totally identified 40 sub-drainage basins, which are inhomogeneously distributed to the north and to the south of the OF. Most of these basins show strong asymmetry, which are mainly tilted to SW. The asymmetry relatively decreases from NE to SW in general. The only exception is at the margins of the Ovacık Basin (OB), where almost the highest asymmetry values were calculated. On the other hand, the characteristics of hypsometric curves and the calculated hypsometric integrals do not show the similar systematic spatial pattern. The hypsometric curves with convex-shaped geometry, naturally indicating relatively young morphology

  2. Proton activity of the Sun in current solar cycle 24

    CERN Document Server

    Li, Chuan; Fang, Cheng

    2014-01-01

    We present a study of 7 large solar proton events (SPEs) of current solar cycle 24 (from 2009 January up to date). They were recorded by GOES spacecraft with highest proton fluxes over 200 pfu for energies $>$10 MeV. In situ particle measurements show that: (1) The profiles of the proton fluxes are highly dependent of the locations of their solar sources, namely flares or coronal mass ejections (CMEs); (2) The solar particle release (SPR) times fall in the decay phase of the flare emission, and are in accordance with the times when the CMEs travel to an average height of 7.9 solar radii; (3) The time differences between the SPR and the flare peak are also dependent of the locations of the solar active regions (ARs). The results tend to support the concept of proton acceleration by the CME-driven shock, even though there exists a possibility of particle acceleration at flare site with subsequent perpendicular diffusion of accelerated particles in the interplanetary magnetic field (IMF). We derive the integral ...

  3. Tectonic Theory and Practice

    DEFF Research Database (Denmark)

    Frier, Marie; Fisker, Anna Marie; Kirkegaard, Poul Henning

    2010-01-01

    defined by Semper as a constructive precondition, a theory for developing a novel tectonic relation between home and system opens up. As a research result the paper suggests a practical spatial exploitation of the actual prefab construction, defining interiority not solely as a visual occupation......’ is an example of this sensuous interior transformation of a house into a home, a level of detailing which is, however, seldom represented in the prefabricated house. Consequently, this paper investigates whether interiority can be developed as a tectonic theory and design principle for uniting home and system...... in the development of novel prefab solutions. This is pursued trough a deductive study comparing Gottfried Semper’s theories on the origins of construction with Werner Blaser’s technical and practical studies of the joint. In combining Blaser’s constructive understanding of the joint with the interior softness...

  4. Towards a Tectonic Approach

    DEFF Research Database (Denmark)

    Hvejsel, Marie Frier; Kirkegaard, Poul Henning; Mortensen, Sophie Bondgaard

    2015-01-01

    Given the increasing environmental and legislative demands to reduce energy consumption, not only new constructions but also the existing urban fabric is about to change radically in the coming decades. Existing buildings cannot simply be restored but must undergo a transformation to comply with ...... the building envelope as an aesthetic ‘gesture’, this paper discusses the architectural challenges related to energy renovation in a Danish context and tectonic design method as an approach to these challenges in everyday practice....

  5. Geomorphic evidence of active tectonics in the San Gorgonio Pass region of the San Andreas Fault system: an example of discovery-based research in undergraduate teaching

    Science.gov (United States)

    Reinen, L. A.; Yule, J. D.

    2014-12-01

    Student-conducted research in courses during the first two undergraduate years can increase learning and improve student self-confidence in scientific study, and is recommended for engaging and retaining students in STEM fields (PCAST, 2012). At Pomona College, incorporating student research throughout the geology curriculum tripled the number of students conducting research prior to their senior year that culminated in a professional conference presentation (Reinen et al., 2006). Here we present an example of discovery-based research in Neotectonics, a second-tier course predominantly enrolling first-and second-year students; describe the steps involved in the four week project; and discuss early outcomes of student confidence, engagement and retention. In the San Gorgonio Pass region (SGPR) in southern California, the San Andreas fault undergoes a transition from predominantly strike-slip to a complex system of faults with significant dip-slip, resulting in diffuse deformation and raising the question of whether a large earthquake on the San Andreas could propagate through the region (Yule, 2009). In spring 2014, seven students in the Neotectonics course conducted original research investigating quantifiable geomorphic evidence of tectonic activity in the SGPR. Students addressed questions of [1] unequal uplift in the San Bernardino Mountains, [2] fault activity indicated by stream knick points, [3] the role of fault style on mountain front sinuosity, and [4] characteristic earthquake slip determined via fault scarp degradation models. Students developed and revised individual projects, collaborated with each other on methods, and presented results in a public forum. A final class day was spent reviewing the projects and planning future research directions. Pre- and post-course surveys show increases in students' self-confidence in the design, implementation, and presentation of original scientific inquiries. 5 of 6 eligible students participated in research the

  6. Tectonic activity and stratigraphic history over the last 130-540 ka on the Southern Shelf of the Sea of Marmara, western North Anatolian Fault, Turkey

    Science.gov (United States)

    Smith, W. H.; Grall, C.; Sorlien, C. C.; Steckler, M. S.; Okay, S.; Cormier, M. H.; Seeber, L.; Cifci, G.; Dondurur, D.

    2016-12-01

    The submerged section of the North Anatolian Fault in the Sea of Marmara, which corresponds to the dextral plate boundary between Eurasia and Anatolia, poses strong hazard for earthquakes and subsequent submarine landslides and tsunamis in the vicinity of the highly populated region of Istanbul. Most of the right-lateral slip is accommodated by the Northern Branch of the North Anatolian Fault (NAF-N), which crosses the central part of the Sea of Marmara and is capable of an earthquake with a magnitude greater than 7. However, both the geology and the geodesy suggest that the NAF-N accommodates only 3/4 of the total slip between the plates. The deformation mechanisms for the rest of the strain (slip distributed on secondary faults, strain partitioning, and diffuse deformation) remains unexplained. Other fault systems, primarily south of the NAF-N, are shown to be important regarding the tectonic evolution of the Sea of Marmara. However, the activity of these peripheral fault systems as well as their relationships with the NAF-N need to be further constrained. For this purpose, a dense dataset of 2D geophysical images (high-resolution seismic reflection data, sparker reflection, CHIRP sub-bottom profiling), as well as multibeam bathymetry, have been acquired in 2008, 2010, 2013 and 2014 during TAMAM and SOMAR cruises, primarily in the southern shelf of the Sea of Marmara. The 15-20 km-wide southern shelf ledge is relatively flat and mostly shallower than 90 m. In this shallow marine region, we have been able to image the detailed stratigraphic record associated with the 125 ka and younger glacio-eustatic cycles and, notably, to identify paleo-shorelines at water depths shallower than 100 m. Several erosional unconformities, laterally correlative to low-stand deltas have been regionally linked to the stratigraphic boundaries previously defined for the last 130-540 ka. While the present-day shelf is relatively flat, a shallow ridge separates the inner and outer parts

  7. Fundamental Active Current Adaptive Linear Neural Networks for Photovoltaic Shunt Active Power Filters

    Directory of Open Access Journals (Sweden)

    Muhammad Ammirrul Atiqi Mohd Zainuri

    2016-05-01

    Full Text Available This paper presents improvement of a harmonics extraction algorithm, known as the fundamental active current (FAC adaptive linear element (ADALINE neural network with the integration of photovoltaic (PV to shunt active power filters (SAPFs as active current source. Active PV injection in SAPFs should reduce dependency on grid supply current to supply the system. In addition, with a better and faster harmonics extraction algorithm, the SAPF should perform well, especially under dynamic PV and load conditions. The role of the actual injection current from SAPF after connecting PVs will be evaluated, and the better effect of using FAC ADALINE will be confirmed. The proposed SAPF was simulated and evaluated in MATLAB/Simulink first. Then, an experimental laboratory prototype was also developed to be tested with a PV simulator (CHROMA 62100H-600S, and the algorithm was implemented using a TMS320F28335 Digital Signal Processor (DSP. From simulation and experimental results, significant improvements in terms of total harmonic distortion (THD, time response and reduction of source power from grid have successfully been verified and achieved.

  8. Universal planetary tectonics (supertectonics)

    Science.gov (United States)

    Kochemasov, G. G.

    2009-04-01

    Universal planetary tectonics (supertectonics) G. Kochemasov IGEM of the Russian Academy of Sciences, Moscow, Russia, kochem.36@mail.ru The wave planetology [1-3 & others] proceeds from the following: "planetary structures are made by orbits and rotations". A uniform reason makes uniform structures. Inertia-gravity waves arising in planetary bodies due to their movements in Keplerian elliptical orbits with periodically changing accelerations warp these bodies in such way that they acquire polyhedron shapes (after interference of standing waves of four directions). Strong Newtonian gravity makes bodies larger than ~400 to 500 km in diameter globular and polyhedra are rarely seen. Only geomorphologic, geologic and geophysical mapping can develop these hidden structures. But small bodies, normally less than ~ 300 to 400 km in diameter, often show parts of the polyhedra, rarely fully developed forms (the asteroid Steins and satellite Amalthea present rather perfect forms of "diamond"). Depending on warping wavelengths (they make harmonics) various Plato's figures superimposed on each other can be distinguished. The fundamental wave 1 produces a tetrahedron, intrinsically dichotomic figure in which a vertex (contraction) always is opposed to a face (expansion). From the recent examples the best is the saturnian northern hexagon (a face) opposed to the southern hurricane (a vertex). The first overtone wave 2 is responsible for creation of structural octahedra. Whole ‘diamonds" and their parts are known [4, 5]. Other overtones produce less developed (because of smaller wave amplitudes) planetary shapes complicating main forms. Thus, the first common structural peculiarity of planetary bodies is their polyhedron nature. Not less important is the second common structural peculiarity. As all globular or smaller more or less isometric bodies rotate, they have an angular momentum. It is inevitably different in tropic and extra-tropic belts having uneven radii or distances to

  9. Geomorphic evidences of recent tectonic activity in the forearc, southern Peru Evidencias geomórficas de actividad tectónica reciente en el Antearco Perú sur

    Directory of Open Access Journals (Sweden)

    L. Audin

    2006-12-01

    Full Text Available As the Andean forearc is not concentrating as much tectonic shortening as the foreland (since Middle Miocene and as GPS measurements can not inform on the long-term deformation but rather describe the elastic response of the Andean forearc (Nazca-South American convergence, little is known about the active deformation in the Central Andes Pacific lowlands. However, geomorphic evidences of recent tectonic activity are observed from the Coastal Cordillera to the piedmont of the Western Cordillera. In this paper we analyze this Quaternary tectonic activity in the southern Peruvian forearc, from 17°S to 18°30'S. Examination of aerial photographs and satellite data, and focused field work not only confirms that there is recent tectonic activity but also has revealed the presence of additional active structures that should be taken into account in the description of Andean deformation. In response to active tectonics, these tectonic structures affected very young terraces and Quaternary pediments in the southern Peruvian forearc. We discuss some of the strong geomorphic signatures, such as active fault traces, scarplets, sag ponds, river terraces and some major and minor landslides, which are indicative of active tectonics in this area. Mapping of fault trace geometry and identifying recent surface offsets are used to determine the key places where active tectonics can be involved in the deformation of the forearc, either through normal faulting, strike-slip faults or thrust faults. Among those major tectonic features, some are likely due to seismic crustal activity (along the ongoing Andean tectonic processes and some to relaxation processes of the stress imposed on the outer forearc area after each major subduction earthquakes.Debido a que el antearco andino no está concentrando tanto acortamiento como el antepaís (desde el Mioceno Medio y como las mediciones de GPS no pueden dar información de la deformación de largo plazo sino que más bien

  10. Is plate tectonics needed to evolve technological species on exoplanets?

    Directory of Open Access Journals (Sweden)

    Robert J. Stern

    2016-07-01

    Full Text Available As we continue searching for exoplanets, we wonder if life and technological species capable of communicating with us exists on any of them. As geoscientists, we can also wonder how important is the presence or absence of plate tectonics for the evolution of technological species. This essay considers this question, focusing on tectonically active rocky (silicate planets, like Earth, Venus, and Mars. The development of technological species on Earth provides key insights for understanding evolution on exoplanets, including the likely role that plate tectonics may play. An Earth-sized silicate planet is likely to experience several tectonic styles over its lifetime, as it cools and its lithosphere thickens, strengthens, and becomes denser. These include magma ocean, various styles of stagnant lid, and perhaps plate tectonics. Abundant liquid water favors both life and plate tectonics. Ocean is required for early evolution of diverse single-celled organisms, then colonies of cells which specialized further to form guts, appendages, and sensory organisms up to the complexity of fish (central nervous system, appendages, eyes. Large expanses of dry land also begin in the ocean, today produced above subduction zones in juvenile arcs and by their coalescence to form continents, although it is not clear that plate tectonics was required to create continental crust on Earth. Dry land of continents is required for further evolution of technological species, where modification of appendages for grasping and manipulating, and improvement of eyes and central nervous system could be perfected. These bioassets allowed intelligent creatures to examine the night sky and wonder, the beginning of abstract thinking, including religion and science. Technology arises from the exigencies of daily living such as tool-making, agriculture, clothing, and weapons, but the pace of innovation accelerates once it is allied with science. Finally, the importance of plate

  11. Active tectonics of the western tethyan himalaya above the underthrusting indian plate: The upper sutlej river basin as a pull-apart structure

    Science.gov (United States)

    Ni, James; Barazangi, Muawia

    1985-03-01

    Fault-bounded blocks and structural elements were mapped in the eastern Ladakh-Spiti and upper Sutlej River Basin located within the Tethyan Himalaya and to the southwest of the Karakorum fault zone mainly using LANDSAT Multispectral Scanner (MSS) band 5, band 7 (near-infrared) images with detailed analysis of smaller areas by interactive digital processing of false color images, and Returned Beam Vidicon (RBV) imagery in conjunction with available topographical, geological and seismological data. For the first time the Leo Pargil Horst and other nearby fault-bounded blocks located at the northwestern end of the upper Setlej River Basin were clearly revealed on the LANDSAT color composites. Shallow crustal seismicity is systematically related to the NNE-trending and N-trending normal faults of the Leo Pargil and nearby regions. Some of the aftershocks of the Kinnaur earthquake of January 19,1975 ( Ms = 6.8), appear to be associated with movement along the NNE-trending westbound fault of the Leo Pargil Horst and the nearby Kaurik-Chango fault. The main shock, however, is teleseismically located at about 30 km to the northwest of the Kaurik-Chango fault. Fault plane solutions of the main shock and two aftershocks indicate a large component of normal faulting. In map view, the upper Sutlej River Basin has an approximately rhomboidal shape and is located to the southwest of the Karakorum fault system. We suggest that this basin is a pull-apart between the NW-SE oriented, right-lateral, strike-slip Karakorum fault system and the high-angle faults near the southern boundary of the Tethyan Himalaya. The Leo Pargil Horst is the northwestern bounding fault block of this pull-apart. The active tectonic features in this part of the Tethyan Himalaya appear to reflect right-shear within the crust, and this is probably a consequence of oblique underthrusting of the Indian continental plate beneath the western Himalaya and southwestern Tibet during the Neogene and Quaternary

  12. Sequence framework of two different kinds of margins and their response to tectonic activity during the Middle-Late Triassic, Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Two kinds of margin respectively occur in the Ordos Basin during the Middle-Late Triassic (Yanchang Age), one is foreland margin developed under the background of flexural subsidence by thrusting intensively in the southwest margin, and the other is intracratonic basin margin by stable subsidence in northern and central parts of the basin. The Middle-Late Triassic Yanchang Formation can be divided into four regional third-order sequences, which are separated by gentle angular unconformity or regional erosion surface, made up of lowstand system tract (LST), expanding system tract (EST) and highstand system tract (HST) from lower to upper within a sequence. But there are distinct differences of the sequence framework between the southwest margin and northern and central parts of the basin. The southwest margin develops heavy conglomerate layer and unconformity as a result of orogeny by thrusting, and the intracratonic basin margin by stable subsidence in the northern and central parts grows aggradational sandstone, conglomerate in fluvio-delta system and parallel unconformity. The depositional framework of southwest margin reflects the tectonic evolution from flexural subsidence by thrusting to rebounded uplift. The formation of sequence boundary is related to the resilient uplift and erosion. The sequence stratigraphic framework and depositional system tract configuration in the foreland basin are controlled by structural activity of the fold and thrust belt, and the sequence succession reflects episodic thrusting of the Middle-Late Triassic toward the foreland basin. The sequence evolution in northern and central parts reflects the depositional succession of fluvio-delta system under intracratonic background, composed of coarse-grained sediment in braided channel deposit at the lower, meandering channel deposit in the middle and fine-grained sediment in the flood plain at the upper, dominated by lake level fluctuation. During the deposit of the LST in the

  13. Cortical hyperpolarization-activated depolarizing current takes part in the generation of focal paroxysmal activities

    Science.gov (United States)

    Timofeev, Igor; Bazhenov, Maxim; Sejnowski, Terrence; Steriade, Mircea

    2002-01-01

    During paroxysmal neocortical oscillations, sudden depolarization leading to the next cycle occurs when the majority of cortical neurons are hyperpolarized. Both the Ca2+-dependent K+ currents (IK(Ca)) and disfacilitation play critical roles in the generation of hyperpolarizing potentials. In vivo experiments and computational models are used here to investigate whether the hyperpolarization-activated depolarizing current (Ih) in cortical neurons also contributes to the generation of paroxysmal onsets. Hyperpolarizing current pulses revealed a depolarizing sag in ≈20% of cortical neurons. Intracellular recordings from glial cells indirectly indicated an increase in extracellular potassium concentration ([K+]o) during paroxysmal activities, leading to a positive shift in the reversal potential of K+-mediated currents, including Ih. In the paroxysmal neocortex, ≈20% of neurons show repolarizing potentials originating from hyperpolarizations associated with depth-electroencephalogram positive waves of spike-wave complexes. The onset of these repolarizing potentials corresponds to maximal [K+]o as estimated from dual simultaneous impalements from neurons and glial cells. Computational models showed how, after the increased [K+]o, the interplay between Ih, IK(Ca), and a persistent Na+ current, INa(P), could organize paroxysmal oscillations at a frequency of 2–3 Hz. PMID:12089324

  14. Remote sub-wavelength focusing of ultrasonically activated Lorentz current

    Science.gov (United States)

    Rekhi, Angad S.; Arbabian, Amin

    2017-04-01

    We propose the use of a combination of ultrasonic and magnetic fields in conductive media for the creation of RF electrical current via the Lorentz force, in order to achieve current generation with extreme sub-wavelength resolution at large depth. We demonstrate the modeling, generation, and measurement of Lorentz current in a conductive solution and show that this current can be localized at a distance of 13 cm from the ultrasonic source to a region about three orders of magnitude smaller than the corresponding wavelength of electromagnetic waves at the same operation frequency. Our results exhibit greater depth, tighter localization, and closer agreement with prediction than previous work on the measurement of Lorentz current in a solution of homogeneous conductivity. The proposed method of RF current excitation overcomes the trade-off between focusing and propagation that is fundamental in the use of RF electromagnetic excitation alone and has the potential to improve localization and depth of operation for RF current-based biomedical applications.

  15. Seismicity of Global Tectonic Systems Obtained from the Harvard CMT Catalogue

    Institute of Scientific and Technical Information of China (English)

    Wang Hui; Zhang Guomin; Ma Hongsheng; Jing Yan

    2005-01-01

    Earthquake is the best information source for describing the present-day crustal tectonic zones and crustal stress field, containing comprehensive and abundant geodynamic connotations.Based on the distribution of global earthquakes and their kinematic and dynamic characteristics, the most active global-scale tectonics can be divided into three first-order tectonic systems: the Circum-Pacific deep subduction tectonic system, the mid-oceanic ridge tectonic system, and the continent-continent shallow underthrusting tectonic system using the Harvard CMT catalogue that provides various parameters of hypocenter. Furthermore, the differences of fault types, seismicity, and distribution of focal depths in different tectonic systems are discussed as well. The results show that different tectonic system possesses different environment and geodynamics.

  16. Seismicity and active tectonics in the Alboran Sea, Western Mediterranean: Constraints from an offshore-onshore seismological network and swath bathymetry data

    OpenAIRE

    Grevemeyer, Ingo; Gràcia, Eulàlia; Villaseñor, Antonio; Leuchters, W.; Watts, A. B.

    2015-01-01

    Seismicity and tectonic structure of the Alboran Sea were derived from a large amphibious seismological network deployed in the offshore basins and onshore in Spain and Morocco, an area where the convergence between the African and Eurasian plates causes distributed deformation. Crustal structure derived from local earthquake data suggests that the Alboran Sea is underlain by thinned continental crust with a mean thickness of about 20 km. During the 5 months of offshore network operation, a t...

  17. Current Management Strategy for Active Surveillance in Prostate Cancer.

    Science.gov (United States)

    Syed, Jamil S; Javier-Desloges, Juan; Tatzel, Stephanie; Bhagat, Ansh; Nguyen, Kevin A; Hwang, Kevin; Kim, Sarah; Sprenkle, Preston C

    2017-02-01

    Active surveillance has been increasingly utilized as a strategy for the management of favorable-risk, localized prostate cancer. In this review, we describe contemporary management strategies of active surveillance, with a focus on traditional stratification schemes, new prognostic tools, and patient outcomes. Patient selection, follow-up strategy, and indication for delayed intervention for active surveillance remain centered around PSA, digital rectal exam, and biopsy findings. Novel tools which include imaging, biomarkers, and genetic assays have been investigated as potential prognostic adjuncts; however, their role in active surveillance remains institutionally dependent. Although 30-50% of patients on active surveillance ultimately undergo delayed treatment, the vast majority will remain free of metastasis with a low risk of dying from prostate cancer. The optimal method for patient selection into active surveillance is unknown; however, cancer-specific mortality rates remain excellent. New prognostication tools are promising, and long-term prospective, randomized data regarding their use in active surveillance will be beneficial.

  18. Transcultural Tectonic Connections

    DEFF Research Database (Denmark)

    Carter, Adrian

    2014-01-01

    This paper presents an understanding of Jørn Utzon, as one of the most profound exponents of a transcultural and tectonic approach to modern architecture in the late twentieth century. The paper will examine the sources of inspiration, intersections and connections in Utzon’s architecture; which...... ruins in Mexico. The Sydney Opera House’s signature sail-like roof shells derive from knowledge of boat building in his youth and ancient Chinese and Japanese temple roofs floating above a stone base. With the choice of ceramic tiles to accentuate the sculptural character of the shells, owing its...

  19. Dynamics of Tectonic Plates

    CERN Document Server

    Pechersky, E; Sadowski, G; Yambartsev, A

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces.

  20. Dynamics of Tectonic Plates

    OpenAIRE

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend ...

  1. Growth of a tectonic ridge

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, R.W.; Messerich, J.A. [Geological Survey, Denver, CO (United States); Johnson, A.M. [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth and Atmospheric Sciences

    1997-12-31

    The 28 June 1992 Landers, California, earthquake of M 7.6 created an impressive record of surface rupture and ground deformation. Fractures extend over a length of more than 80 km including zones of right-lateral shift, steps in the fault zones, fault intersections and vertical changes. Among the vertical changes was the growth of a tectonic ridge described here. In this paper the authors describe the Emerson fault zone and the Tortoise Hill ridge including the relations between the fault zone and the ridge. They present data on the horizontal deformation at several scales associated with activity within the ridge and belt of shear zones and show the differential vertical uplifts. And, they conclude with a discussion of potential models for the observed deformation.

  2. Late Pliocene To Pleistocene Tectonic Activity In SW Portugal: The S.Teotónio-Aljezur- Sinceira Fault System And Evidence For Coastal Uplift

    Science.gov (United States)

    Figueiredo, P.; Cabral, J.; Rockwell, T.

    2008-12-01

    mainly by Mesozoic limestones and exhibits a generally lower topography accented by karstic morphology. In both areas, little work has been done to map the sequence of marine terraces, nor to determine their ages, although the majority of them are likely Pleistocene. The highest raised marine deposits reach an altitude of 370 m ~13 km inland and may be as old as Pliocene in age. Inland, the Säo Teotónio-Aljezur-Sinceira fault system (STASFS) extends NNE-SSW for 50 km, parallel and close to the southwest Portuguese coast, and controls the development of several small Cenozoic tectonic basins. It comprises onshore faults which may relate to the ongoing plate boundary deformation. This fault system expresses primarily sinistral strike-slip with a minor reverse component. Four cenozoic strike-slip basins occur along the STASFS, generally with lengths of less than 5 km and a maximum width of 1.5 km, filled with Miocene to Pleistocene sediments. In some areas, fault-related post-Pliocene vertical displacements of up to 100 m may have occurred, but generally they only reach a few tens of meters. This coastal region is therefore particularly appropriate for establishing the offshore-onshore link through a detailed neotectonic study of the active faults, including exploration with paleoseismological techniques, and the vertical deformation field using marine terraces as a reference frame.

  3. A Laboratory Activity on the Eddy Current Brake

    Science.gov (United States)

    Molina-Bolivar, J. A.; Abella-Palacios, A. J.

    2012-01-01

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and…

  4. Integrated multi-parameters Probabilistic Seismic Landslide Hazard Analysis (PSLHA): an innovative approach in the active volcano-tectonic area of Campi Flegrei (Italy)

    Science.gov (United States)

    Caccavale, M.; Matano, F.; Sacchi, M.; Somma, R.; Troise, C.; De Natale, G.

    2013-12-01

    The western coastal sector of Campania region (southern Italy) is characterised by the presence of the active volcano-tectonic area of Campi Flegrei. This area represents a very particular and interesting case-study for a probabilistic seismic hazard analysis (PSHA). The principal seismic source, related with the caldera, is not clearly constrained in the on-shore and off-shore areas. The well-known and monitored phenomenon of bradyseism affecting a large portion of case-study area is not modelled in the standard PSHA approach. From the environmental point of view the presence of very high exposed values in terms of population, buildings, infrastructures and palaces of high archaeological, natural and artistic value, makes this area a strategic natural laboratory to develop new methodologies. Moreover the geomorphological and geo-volcanological features lead to a heterogeneous coastline, made up by both beach and tuff cliffs, rapidly evolving for erosion and landslide (i.e. mainly rock fall and rock slide) phenomena that represent an additional hazard aspect. In the Campi Flegrei the possible occurrence of a moderate/large seismic event represents a serious threat for the inhabitants, for the infrastructures as well as for the environment. In the framework of Italian MON.I.C.A project (sinfrastructural coastlines monitoring) an innovative and dedicated probabilistic methodology has been applied to identify the areas with higher tendency of landslide occurrence due to the seismic effect. Resident population reported the occurrence of some small rock falls along tuff quarry slopes during the main shocks of the 1982-84 bradyseismic events. The PSHA methodology, introduced by Cornell (1968), combines the contributions to the hazard from all potential sources of earthquakes and the average activity rates associated to each seismogenic zone considered. The result of the PSHA is represented by the spatial distribution of a ground-motion (GM) parameter A, such as Peak

  5. Indonesian Landforms and Plate Tectonics

    Directory of Open Access Journals (Sweden)

    Herman Th. Verstappen

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v5i3.103The horizontal configuration and vertical dimension of the landforms occurring in the tectonically unstable parts of Indonesia were resulted in the first place from plate tectonics. Most of them date from the Quaternary and endogenous forces are ongoing. Three major plates – the northward moving Indo-Australian Plate, the south-eastward moving SE-Asian Plate and the westward moving Pacific Plate - meet at a plate triple-junction situated in the south of New Guinea’s Bird’s Head. The narrow North-Moluccan plate is interposed between the Asia and Pacific. It tapers out northward in the Philippine Mobile Belt and is gradually disappearing. The greatest relief amplitudes occur near the plate boundaries: deep ocean trenches are associated with subduction zones and mountain ranges with collision belts. The landforms of the more stable areas of the plates date back to a more remote past and, where emerged, have a more subdued relief that is in the first place related to the resistance of the rocks to humid tropical weathering Rising mountain ranges and emerging island arcs are subjected to rapid humid-tropical river erosions and mass movements. The erosion products accumulate in adjacent sedimentary basins where their increasing weight causes subsidence by gravity and isostatic compensations. Living and raised coral reefs, volcanoes, and fault scarps are important geomorphic indicators of active plate tectonics. Compartmental faults may strongly affect island arcs stretching perpendicular to the plate movement. This is the case on Java. Transcurrent faults and related pull-apart basins are a leading factor where plates meet at an angle, such as on Sumatra. The most complicated situation exists near the triple-junction and in the Moluccas. Modern research methods, such as GPS measurements of plate movements and absolute dating of volcanic outbursts and raised coral reefs are important tools. The mega-landforms resulting

  6. Indonesian Landforms and Plate Tectonics

    Directory of Open Access Journals (Sweden)

    Herman Th. Verstappen

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v5i3.103The horizontal configuration and vertical dimension of the landforms occurring in the tectonically unstable parts of Indonesia were resulted in the first place from plate tectonics. Most of them date from the Quaternary and endogenous forces are ongoing. Three major plates – the northward moving Indo-Australian Plate, the south-eastward moving SE-Asian Plate and the westward moving Pacific Plate - meet at a plate triple-junction situated in the south of New Guinea’s Bird’s Head. The narrow North-Moluccan plate is interposed between the Asia and Pacific. It tapers out northward in the Philippine Mobile Belt and is gradually disappearing. The greatest relief amplitudes occur near the plate boundaries: deep ocean trenches are associated with subduction zones and mountain ranges with collision belts. The landforms of the more stable areas of the plates date back to a more remote past and, where emerged, have a more subdued relief that is in the first place related to the resistance of the rocks to humid tropical weathering Rising mountain ranges and emerging island arcs are subjected to rapid humid-tropical river erosions and mass movements. The erosion products accumulate in adjacent sedimentary basins where their increasing weight causes subsidence by gravity and isostatic compensations. Living and raised coral reefs, volcanoes, and fault scarps are important geomorphic indicators of active plate tectonics. Compartmental faults may strongly affect island arcs stretching perpendicular to the plate movement. This is the case on Java. Transcurrent faults and related pull-apart basins are a leading factor where plates meet at an angle, such as on Sumatra. The most complicated situation exists near the triple-junction and in the Moluccas. Modern research methods, such as GPS measurements of plate movements and absolute dating of volcanic outbursts and raised coral reefs are important tools. The mega-landforms resulting

  7. Extensional Tectonic Regime of Garut Basin based on Magnetotelluric Analysis

    Directory of Open Access Journals (Sweden)

    Lina Handayani

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i3.162Garut Basin are is part of Bandung-Garut Greater Basin (Bandung Zone characterized by a large basin surrounded by mountain ranges. Active volcanoes had distributed their material as pyroclastic deposits around the outer border of the zone and as lava flow deposit separating the two basins. Bouguer gravity anomaly data had also indicated the presence of several low anomaly closures at about the area of Bandung and Garut Basins that were surrounded by high gravity anomaly zones. Two magnetotelluric surveys were completed to acquire the subsurface model that might explain the tectonic evolution of studied area. The first stage was characterized sby the presence of horst - graben structures that might imply an extensional regime of the area. The next stage of evolutionwas indicated by the horizontal layering correlated to the relative non-active tectonic. In addition, a most recent structure that appeared near the surface might suggest a possible extension force as the current stage.

  8. Get Current: Switch on Clean Energy Activity Book

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-06-01

    Switching on clean energy technologies means strengthening the economy while protecting the environment. This activity book for all ages promotes energy awareness, with facts on different types of energy and a variety of puzzles in an energy theme.

  9. New RC-Active Networks Using Current Conveyors

    Directory of Open Access Journals (Sweden)

    V. Zeman

    1997-06-01

    Full Text Available Two novel autonomous networks containing current conveyors are presented. The design of second-order oscillators and frequency filters based on the above general networks is described. The Q-factor of the circuits designed is controllable through a grounded single resistor. Some examples illustrate the procedure described. Two new one-port elements for high-order immittance realization are shown.

  10. New research progress on the ultrastructure of tectonically deformed coals

    Institute of Scientific and Technical Information of China (English)

    Yiwen Ju; Xiaoshi Li

    2009-01-01

    The structure of tectonically deformed coals shows some characteristics and regulations on the ultra-scale when influenced by different factors such as temperature, pressure and directional stress. Deformations of the macromolecular structure may induce changes in the nano-scale pore structure, which are very important for gas adsorption and pervasion. The geological impact of different mechanisms of deformation on different types of ultrastructure of tectonically deformed coals is not only of significance as a topic for scientific research, but also in studying environments of metamorphism-deformation at differing metamorphic stages. This research is also very important in studying the accumulation and occurrence conditions of coalbed methane gas, mechanisms of coal and gas outbursts, predictions of coalbed methane resources and dangers of coal and gas outbursts. This paper analyzes current research, within China and other coun-tries, in the ultrastructure of tectonically deformed coals. The research includes (1) structural models of tectonically deformed coals; (2) the relationship between ultrastructure and stress; (3) the structure of tectonically deformed coals and its strain environment. These results are also based on our own experiments including vitirnite reflectance (R_(o,max)), X-ray diffraction (XRD) and nuclear magnetic res-onance (NMR (CP/MAS+TOSS)). We discuss the important effects of the structure of tectonically deformed coals and their physical properties, and then point out some problems concerning the research progress of tectonically deformed coals.

  11. Landscapes of human evolution: models and methods of tectonic geomorphology and the reconstruction of hominin landscapes.

    Science.gov (United States)

    Bailey, Geoffrey N; Reynolds, Sally C; King, Geoffrey C P

    2011-03-01

    This paper examines the relationship between complex and tectonically active landscapes and patterns of human evolution. We show how active tectonics can produce dynamic landscapes with geomorphological and topographic features that may be critical to long-term patterns of hominin land use, but which are not typically addressed in landscape reconstructions based on existing geological and paleoenvironmental principles. We describe methods of representing topography at a range of scales using measures of roughness based on digital elevation data, and combine the resulting maps with satellite imagery and ground observations to reconstruct features of the wider landscape as they existed at the time of hominin occupation and activity. We apply these methods to sites in South Africa, where relatively stable topography facilitates reconstruction. We demonstrate the presence of previously unrecognized tectonic effects and their implications for the interpretation of hominin habitats and land use. In parts of the East African Rift, reconstruction is more difficult because of dramatic changes since the time of hominin occupation, while fossils are often found in places where activity has now almost ceased. However, we show that original, dynamic landscape features can be assessed by analogy with parts of the Rift that are currently active and indicate how this approach can complement other sources of information to add new insights and pose new questions for future investigation of hominin land use and habitats.

  12. Developing an Education and Public Outreach (EPO) program for Caltech's Tectonics Observatory

    Science.gov (United States)

    Kovalenko, L.; Jain, K.; Maloney, J.

    2012-12-01

    The Caltech Tectonics Observatory (TO) is an interdisciplinary center, focused on geological processes occurring at the boundaries of Earth's tectonic plates (http://www.tectonics.caltech.edu). Over the past four years, the TO has made a major effort to develop an Education and Public Outreach (EPO) program. Our goals are to (1) inspire students to learn Earth Sciences, particularly tectonic processes, (2) inform and educate the general public about science in the context of TO discoveries, and (3) provide opportunities for graduate students, postdocs, and faculty to do outreach in the local K-12 schools and community colleges. Our work toward these goals includes hosting local high school teachers and students each summer for six weeks of research experience (as part of Caltech's "Summer Research Connection"); organizing and hosting an NAGT conference aimed at Geoscience teachers at community colleges; participating in teacher training workshops (organized by the local school district); hosting tours for K-12 students from local schools as well as from China; and bringing hands-on activities into local elementary, middle, and high school classrooms. We also lead local school students and teachers on geology field trips through nearby canyons; develop education modules for undergraduate classes (as part of MARGINS program); write educational web articles on TO research (http://www.tectonics.caltech.edu/outreach/highlights/), and regularly give presentations to the general public. This year, we started providing content expertise for the development of video games to teach Earth Science, being created by GameDesk Institute. And we have just formed a scientist/educator partnership with a 6th grade teacher, to help in the school district's pilot program to incorporate new national science standards (NSTA's Next Generation Science Standards, current draft), as well as use Project-Based Learning. This presentation gives an overview of these activities.

  13. Influence of paired subduction zones: insight into Central Mediterranean tectonics

    Science.gov (United States)

    Miller, Meghan Samantha; Moresi, Louis; Faccenna, Claudio; Funiciello, Francesca

    2015-04-01

    The Hellenic and Calabrian slabs are subducting the last remnant of the Ionian oceanic lithosphere into the deep mantle beneath the Central Mediterranean. Seismic tomography studies have provided clear images of the present day morphology of the subducted lithosphere [1]. Tectonic studies have shown that the Calabrian slab has rolled back into its current geometry with episodes of back-arc spreading that have now ceased [2]. Conversely, GPS observations along with tectonic reconstructions show that the Hellenic slab is currently rolling back and appears to have accelerated in the past ~15 My [3], which has resulted in the only region of backarc spreading still active in the Mediterranean. Observations of seismic anisotropy from SKS splitting [4] indicate toroidal flow patterns at the edges of the subducted slabs, which lead to interpretations of mantle convection and flow. Rollback in a confined setting has allowed the two slabs to become a plate-tectonic pushmi-pullyu [5]. The evolution of each slab is necessarily dependent on the other as they are both subducting the same lithosphere in opposite directions and are sufficiently close together that their induced mantle flow patterns must interact strongly. Although this seems to be an oddity in the classical picture of plate tectonics, we note that rollback-dominated subduction is more likely to be important in the highly-confined setting of a closing ocean where the oceanic lithosphere is not always able to develop into a freely-moving plate. Under such conditions, back-to-back pairings of subducting slabs are potentially more common. To investigate this setting, we present preliminary numerical models of paired subduction zones that we have developed using Underworld. We include variations in the strength and buoyancy of the surrounding (over-riding) plates and account for the presence of continentally-derived basement in the Adriatic sea. The geodynamic models allow for exploration into the timing, mechanics

  14. Icing Branch Current Research Activities in Icing Physics

    Science.gov (United States)

    Vargas, Mario

    2009-01-01

    Current development: A grid block transformation scheme which allows the input of grids in arbitrary reference frames, the use of mirror planes, and grids with relative velocities has been developed. A simple ice crystal and sand particle bouncing scheme has been included. Added an SLD splashing model based on that developed by William Wright for the LEWICE 3.2.2 software. A new area based collection efficiency algorithm will be incorporated which calculates trajectories from inflow block boundaries to outflow block boundaries. This method will be used for calculating and passing collection efficiency data between blade rows for turbo-machinery calculations.

  15. Power-Integrated Circuit Active Leakage Current Detector

    Directory of Open Access Journals (Sweden)

    M. F. Bulacio

    2012-01-01

    Full Text Available Most of the failures of induction motors become insulation faults, causing a permanent damage. Using differential current transformers, a system capable of insulation fault detection was developed, based on the differential relay protection scheme. Both signal injection and fault detection circuitry were integrated in a single chip. The proposed scheme is faster than other existing protection and not restricted to protect induction motors, but several other devices (such as IGBTs and systems. This paper explains the principle of operation of fault protection scheme and analyzes an integrated implementation through simulations and experimental results. A power-integrated circuit (PIC implementation is presented.

  16. Wall conditioning for ITER: Current experimental and modeling activities

    Energy Technology Data Exchange (ETDEWEB)

    Douai, D., E-mail: david.douai@cea.fr [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Kogut, D. [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Wauters, T. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Brezinsek, S. [FZJ, Institut für Energie- und Klimaforschung Plasmaphysik, 52441 Jülich (Germany); Hagelaar, G.J.M. [Laboratoire Plasma et Conversion d’Energie, UMR5213, Toulouse (France); Hong, S.H. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Lomas, P.J. [CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Lyssoivan, A. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Nunes, I. [Associação EURATOM-IST, Instituto de Plasmas e Fusão Nuclear, 1049-001 Lisboa (Portugal); Pitts, R.A. [ITER International Organization, F-13067 St. Paul lez Durance (France); Rohde, V. [Max-Planck-Institut für Plasmaphysik, 85748 Garching (Germany); Vries, P.C. de [ITER International Organization, F-13067 St. Paul lez Durance (France)

    2015-08-15

    Wall conditioning will be required in ITER to control fuel and impurity recycling, as well as tritium (T) inventory. Analysis of conditioning cycle on the JET, with its ITER-Like Wall is presented, evidencing reduced need for wall cleaning in ITER compared to JET–CFC. Using a novel 2D multi-fluid model, current density during Glow Discharge Conditioning (GDC) on the in-vessel plasma-facing components (PFC) of ITER is predicted to approach the simple expectation of total anode current divided by wall surface area. Baking of the divertor to 350 °C should desorb the majority of the co-deposited T. ITER foresees the use of low temperature plasma based techniques compatible with the permanent toroidal magnetic field, such as Ion (ICWC) or Electron Cyclotron Wall Conditioning (ECWC), for tritium removal between ITER plasma pulses. Extrapolation of JET ICWC results to ITER indicates removal comparable to estimated T-retention in nominal ITER D:T shots, whereas GDC may be unattractive for that purpose.

  17. River history and tectonics.

    Science.gov (United States)

    Vita-Finzi, C

    2012-05-13

    The analysis of crustal deformation by tectonic processes has gained much from the clues offered by drainage geometry and river behaviour, while the interpretation of channel patterns and sequences benefits from information on Earth movements before or during their development. The interplay between the two strands operates at many scales: themes which have already benefited from it include the possible role of mantle plumes in the breakup of Gondwana, the Cenozoic development of drainage systems in Africa and Australia, Himalayan uplift in response to erosion, alternating episodes of uplift and subsidence in the Mississippi delta, buckling of the Indian lithospheric plate, and changes in stream pattern and sinuosity along individual alluvial channels subject to localized deformation. Developments in remote sensing, isotopic dating and numerical modelling are starting to yield quantitative analyses of such effects, to the benefit of geodymamics as well as fluvial hydrology.

  18. Intermittent plate tectonics?

    Science.gov (United States)

    Silver, Paul G; Behn, Mark D

    2008-01-04

    Although it is commonly assumed that subduction has operated continuously on Earth without interruption, subduction zones are routinely terminated by ocean closure and supercontinent assembly. Under certain circumstances, this could lead to a dramatic loss of subduction, globally. Closure of a Pacific-type basin, for example, would eliminate most subduction, unless this loss were compensated for by comparable subduction initiation elsewhere. Given the evidence for Pacific-type closure in Earth's past, the absence of a direct mechanism for termination/initiation compensation, and recent data supporting a minimum in subduction flux in the Mesoproterozoic, we hypothesize that dramatic reductions or temporary cessations of subduction have occurred in Earth's history. Such deviations in the continuity of plate tectonics have important consequences for Earth's thermal and continental evolution.

  19. Plate Tectonics: A Paradigm under Threat.

    Science.gov (United States)

    Pratt, David

    2000-01-01

    Discusses the challenges confronting plate tectonics. Presents evidence that contradicts continental drift, seafloor spreading, and subduction. Reviews problems posed by vertical tectonic movements. (Contains 242 references.) (DDR)

  20. Plate Tectonics: A Paradigm under Threat.

    Science.gov (United States)

    Pratt, David

    2000-01-01

    Discusses the challenges confronting plate tectonics. Presents evidence that contradicts continental drift, seafloor spreading, and subduction. Reviews problems posed by vertical tectonic movements. (Contains 242 references.) (DDR)

  1. Public regulations towards a tectonic architecture

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due

    2006-01-01

    Public regulations can support tectonic architecture by changes to the tendering system, supporting new organizational structures of the building industry in public building projects and suggesting a focus on innovation through increased research and development activity. The Danish state......'s activities has primarily been to support the optimization of the building process through ‘trimmed building’ and ‘partnering’ that only takes the immediate economic benefits of the changes to the building process into account and as such has no measures for architectural quality. The public initiatives so...... are happening very slowly which is understandable when there is no economic incitement for the industry to change. A change of these public regulations from sticks to carrots could create the economic incitement for the building industry to create tectonic architecture and thereby develop the building industry...

  2. Current status of pyrazole and its biological activities.

    Science.gov (United States)

    Naim, Mohd Javed; Alam, Ozair; Nawaz, Farah; Alam, Md Jahangir; Alam, Perwaiz

    2016-01-01

    Pyrazole are potent medicinal scaffolds and exhibit a full spectrum of biological activities. This review throws light on the detailed synthetic approaches which have been applied for the synthesis of pyrazole. This has been followed by an in depth analysis of the pyrazole with respect to their medical significance. This follow-up may help the medicinal chemists to generate new leads possessing pyrazole nucleus with high efficacy.

  3. The interpretation of crustal dynamics data in terms of plate interactions and active tectonics of the Anatolian plate and surrounding regions in the Middle East

    Science.gov (United States)

    Toksoz, M. Nafi; Reilinger, Robert

    1992-01-01

    A detailed study was made of the consequences of the Arabian plate convergence against Eurasia and its effects on the tectonics of Anatolia and surrounding regions of the eastern Mediterranean. A primary source of information is time rates of change of baseline lengths and relative heights determined by repeated SLR measurements. These SLR observations are augmented by a network of GPS stations in Anatolia, Aegea, and Greece, established and twice surveyed since 1988. The existing SLR and GPS networks provide the spatial resolution necessary to reveal the details of ongoing tectonic processes in this area of continental collision. The effort has involved examining the state of stress in the lithosphere and relative plate motions as revealed by these space based geodetic measurements, seismicity, and earthquake mechanisms as well as the aseismic deformations of the plates from conventional geodetic data and geological evidence. These observations are used to constrain theoretical calculations of the relative effects of: (1) the push of the Arabian plate; (2) high topography of Eastern Anatolia; (3) the geometry and properties of African-Eurasian plate boundary; (4) subduction under the Hellenic Arc and southwestern Turkey; and (5) internal deformation and rotation of the Anatolian plate.

  4. Zircon and apatite fission track analyses on mineralization ages and tectonic activities of Tuwu-Yandong porphyry copper deposit in northern Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The mineralization ages reported in the past in the Tuwu-Yandong copper district not only are different, but also fall into the Hercynian epoch. This study has achieved 9 zircon and 7 apatite fission track analysis results. The zircon fission track ages range from 158 Ma to 289 Ma and the apatite ages are between 64 Ma and 140 Ma. The mineralization accords with the regional tectonics in the copper district. We consider that the zircon fission track age could reveal the mineralization age based on annealing zone temperature of 140-300℃ and retention temperature of ~250℃ for zircon fission track, and metallogenetic temperature of 120-350℃ in this ore district. Total three mineralization epochs have been identified, i.e., 289-276 Ma,232-200 Ma and 165-158 Ma, and indicate occurrence of the mineralization in the Indosinian and Yanshan epochs. Corresponding to apatite fission track ages, the three tectonic-mineralizing epochs are 140-132 Ma, 109-97 Ma and 64 Ma, which means age at about 100℃ after the mineralization. The three epochs lasted 146 Ma, 108 Ma and about 100 Ma from ~250℃ to ~100℃ and trend decrease from early to late. It is shown by the fission track modeling that this district underwent three stages of geological thermal histories, stable in Cretaceous and cooling both before Cretaceous and after 20 Ma.

  5. Proton currents constrain structural models of voltage sensor activation

    Science.gov (United States)

    Randolph, Aaron L; Mokrab, Younes; Bennett, Ashley L; Sansom, Mark SP; Ramsey, Ian Scott

    2016-01-01

    The Hv1 proton channel is evidently unique among voltage sensor domain proteins in mediating an intrinsic ‘aqueous’ H+ conductance (GAQ). Mutation of a highly conserved ‘gating charge’ residue in the S4 helix (R1H) confers a resting-state H+ ‘shuttle’ conductance (GSH) in VGCs and Ci VSP, and we now report that R1H is sufficient to reconstitute GSH in Hv1 without abrogating GAQ. Second-site mutations in S3 (D185A/H) and S4 (N4R) experimentally separate GSH and GAQ gating, which report thermodynamically distinct initial and final steps, respectively, in the Hv1 activation pathway. The effects of Hv1 mutations on GSH and GAQ are used to constrain the positions of key side chains in resting- and activated-state VS model structures, providing new insights into the structural basis of VS activation and H+ transfer mechanisms in Hv1. DOI: http://dx.doi.org/10.7554/eLife.18017.001 PMID:27572256

  6. Current activities of the Yersinia effector protein YopM.

    Science.gov (United States)

    Höfling, Sabrina; Grabowski, Benjamin; Norkowski, Stefanie; Schmidt, M Alexander; Rüter, Christian

    2015-05-01

    Yersinia outer protein M (YopM) belongs to the group of Yop effector proteins, which are highly conserved among pathogenic Yersinia species. During infection, the effectors are delivered into the host cell cytoplasm via the type 3 secretion system to subvert the host immune response and support the survival of Yersinia. In contrast to the other Yop effectors, YopM does not possess a known enzymatic activity and its molecular mechanism(s) of action remain(s) poorly understood. However, YopM was shown to promote colonization and dissemination of Yersinia, thus being crucial for the pathogen's virulence in vivo. Moreover, YopM interacts with several host cell proteins and might utilize them to execute its anti-inflammatory activities. The results obtained so far indicate that YopM is a multifunctional protein that counteracts the host immune defense by multiple activities, which are at least partially independent of each other. Finally, its functions seem to be also influenced by differences between the specific YopM isoforms expressed by Yersinia subspecies. In this review, we focus on the global as well as more specific contribution of YopM to virulence of Yersinia during infection and point out the various extra- and intracellular molecular functions of YopM. In addition, the novel cell-penetrating ability of recombinant YopM and its potential applications as a self-delivering immunomodulatory therapeutic will be discussed. Copyright © 2015 Elsevier GmbH. All rights reserved.

  7. Index of current water-resources activities in Ohio, 1985

    Science.gov (United States)

    Eberle, Michael

    1985-01-01

    This report summarizes the U. S. Geological Survey 's Water Resources Division 's program in Ohio in 1985. The work of the Ohio District is carried out through the District office in Columbus and a field office in New Philadelphia. Collection of basic data needed for continuing determination and evaluation of the quantity, quality, and use of Ohio 's water resources is the responsibility of the District 's Hydrologic Surveillance Section. The Hydrologic Investigations Section conducts analytical and interpretive water-resource appraisals describing the occurrence, availability, and the physical, chemical, and biological characteristics of surface and groundwater. In addition to introductory material describing the structure of the Ohio District, information is presented on current projects, sites at which basic surface- and groundwater data are collected , and reports of Ohio 's water resources published by the U.S. Geological Survey and cooperating agencies. (USGS)

  8. A laboratory activity on the eddy current brake

    Science.gov (United States)

    Molina-Bolívar, J. A.; Abella-Palacios, A. J.

    2012-05-01

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and electromagnetic properties of the magnet on the magnetic drag force. This video-based experiment is ideal for the study of kinematic graphs and the application of Newton's laws. Video motion analysis software enables students to make precise measurements of the magnet's position at incremental times during its motion, thus allowing them to quantify electromagnetic induction phenomena. The equipment needed for this experiment and data collection software are present in most physics teaching laboratories or are inexpensive and available.

  9. Plate tectonics drive tropical reef biodiversity dynamics.

    Science.gov (United States)

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J; de Santana, Charles N; Heine, Christian; Mouillot, David; Bellwood, David R; Pellissier, Loïc

    2016-05-06

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics.

  10. Plate tectonics drive tropical reef biodiversity dynamics

    Science.gov (United States)

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F.; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J.; de Santana, Charles N.; Heine, Christian; Mouillot, David; Bellwood, David R.; Pellissier, Loïc

    2016-01-01

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics. PMID:27151103

  11. Plate tectonics drive tropical reef biodiversity dynamics

    Science.gov (United States)

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F.; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J.; de Santana, Charles N.; Heine, Christian; Mouillot, David; Bellwood, David R.; Pellissier, Loïc

    2016-05-01

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics.

  12. Current status of neutron activation analysis in HANARO Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Moon, Jong Hwa; Sohn, Jae Min [Korea Atomic Energy Research Institute, Daejeon (Korea)

    2003-03-01

    The facilities for neutron activation analysis in the HANARO (Hi-flux Advanced Neutron Application Research Reactor) are described and the main applications of NAA (Neutron Activation Analysis) are reviewed. The sample irradiation tube, automatic and manual pneumatic transfer system were installed at three irradiation holes of HANARO at the end of 1995. The performance of the NAA facility was examined to identify the characteristics of the tube transfer system, irradiation sites and custom-made polyethylene irradiation capsule. The available thermal neutron fluxes at irradiation sites are in the range of 3 x 10{sup 13} - 1 x 10{sup 14} n/cm{sup 2}{center_dot}s and cadmium ratios are in 15 - 250. For an automatic sample changer for gamma-ray counting, a domestic product was designed and manufactured. An integrated computer program (Labview) to analyse the content was developed. In 2001, PGNAA (Prompt Gamma Neutron Activation Analysis) facility has been installed using a diffracted neutron beam of ST1. NAA has been applied in the trace component analysis of nuclear, geological, biological, environmental and high purity materials, and various polymers for research and development. The improvement of analytical procedures and establishment of an analytical quality control and assurance system were studied. Applied research and development for the environment, industry and human health by NAA and its standardization were carried out. For the application of the KOLAS (Korea Laboratory Accreditation Scheme), evaluation of measurement uncertainty and proficiency testing of reference materials were performed. Also to verify the reliability and to validate analytical results, intercomparison studies between laboratories were carried out. (author)

  13. [Active teaching-learning methodologies in health education: current debates].

    Science.gov (United States)

    Mitre, Sandra Minardi; Siqueira-Batista, Rodrigo; Girardi-de-Mendonça, José Márcio; de Morais-Pinto, Neila Maria; Meirelles, Cynthia de Almeida Brandão; Pinto-Porto, Cláudia; Moreira, Tânia; Hoffmann, Leandro Marcial Amaral

    2008-12-01

    The vertiginous transformations of the contemporary societies have been raising questions concerning aspects of professional education. Such questions have been raised in a more and more incisive way. This debate gains a new shape when applied to health work, where theory and practice cannot be dissociated, and where the development of an integral vision of the human being and the amplification of the concept care are essential for a proper performance. Based on these considerations, this article aims to discuss the main methodological transformations in the education process of health professionals, with emphasis to active teaching-learning methodologies.

  14. Antimicrobial activity of carvacrol: current progress and future prospectives.

    Science.gov (United States)

    Nostro, Antonia; Papalia, Teresa

    2012-04-01

    During the last few years the scientific community has shown a considerable interest in the study of plant materials as sources of new compounds to be processed into antimicrobial agents. In this context, carvacrol, a monoterpenic phenol, has emerged for its wide spectrum activity extended to food spoilage or pathogenic fungi, yeast and bacteria as well as human, animal and plant pathogenic microorganisms including drug-resistant and biofilm forming microorganisms. The antibacterial activity of carvacrol has been attributed to its considerable effects on the structural and functional properties of cytoplasmatic membrane. The data reported in this review provide an overview of the published literature regarding the antimicrobial properties of carvacrol and the recent patents claimed in order to highlight its future applications as a new antimicrobial agent. These could concern either the natural preservation in the cosmetic and food industries or an alternative which supports the conventional antimicrobial protocols. Interestingly, carvacrol alone or associated with one or more synergistic products could be incorporated in different formulations for biomedical and food packaging applications. However, more detailed safety investigations and in vivo studies should be carried out so that this molecule could be used in the future.

  15. Application and interpretation of current autophagy inhibitors and activators

    Institute of Scientific and Technical Information of China (English)

    Ya-ping YANG; Li-fang HU; Hui-fen ZHENG; Cheng-jie MAO; Wei-dong HU; Kang-ping XIONG; Fen WANG

    2013-01-01

    Aut ophagy is the major intracellular degradation system,by which cytoplasmic materials are delivered to and degraded in the lysosome.As a quality control mechanism for cytoplasmic proteins and organelles,autophagy plays important roles in a variety of human diseases,including neurodegenerative diseases,cancer,cardiovascular disease,diabetes and infectious and inflammatory diseases.The discovery of ATG genes and the dissection of the signaling pathways involved in regulating autophagy have greatly enriched our knowledge on the occurrence and development of this lysosomal degradation pathway.In addition to its role in degradation,autophagy may also promote a type of programmed cell death that is different from apoptosis,termed type II programmed cell death.Owing to the dual roles of autophagy in cell death and the specificity of diseases,the exact mechanisms of autophagy in various diseases require more investigation.The application of autophagy inhibitors and activators will help us understand the regulation of autophagy in human diseases,and provide insight into the use of autophagy-targeted drugs.In this review,we summarize the latest research on autophagy inhibitors and activators and discuss the possibility of their application in human disease therapy.

  16. Development of a glacially dominated shelf-slope-fan system in tectonically active southeast Alaska: Results of IODP Expedition 341 core-log-seismic integrated studies at glacial cycle resolution

    Science.gov (United States)

    Gulick, Sean; Jaeger, John; Mix, Alan; Swartz, John; Worthington, Lindsay; Reece, Robert

    2014-05-01

    Collision of the Yakutat microplate with North American formed the St. Elias Mountains in coastal Gulf of Alaska. While the tectonic driver for orogenesis has been ongoing since the Miocene, results from the Integrated Ocean Drilling Program Expedition 341 suggests that direct climatic perturbation of active orogenesis through glacial erosion is non-linear. Geophysical studies of the glaciated continental margin, slope, and adjacent deep-sea Surveyor Fan allow examination of the glaciated orogen from source to sink. Using high-resolution and crustal-scale seismic data and through comparison with other glaciated margins, we can identify key diagnostic seismic morphologies and facies indicative of glacial proximity and sediment routing. Expedition drilling results calibrated these images suggesting a timeline for initial advances of the Cordilleran ice sheet related glacial systems onto the shelf and a further timeline for the development of ice streams that reach the shelf edge. Comparisons can be made within this single margin between evolution of the tectonic-glacial system where erosion and sediment transport are occurring within a fold and thrust belt versus on a more stable shelf region. Onshore the Bering-Bagley glacial system in the west flows across the Yakataga fold and thrust belt, allowing examination of whether glacial erosion can cause tectonic feedbacks, whereas offshore the Bering-Bagley system interacts with the Pamplona Zone thrusts in a region of significant sediment accommodation. Results from Expedition 341 imply that timing of glacial advance to the shelf edge in this region may be driven by the necessity of filling up the accommodation through aggradation followed by progradation and thus is autogenic. In contrast the Malaspina-Hubbard glacial system to the east encountered significantly less accommodation and more directly responded to climatic forcing including showing outer shelf glacial occupation since the mid-Pleistocene transition-MPT to

  17. Applications and limitations of thermobarometry in migmatites and granulites using as an example rocks of the Araçuaí Orogen in southern Bahia, including a discussion on the tectonic meaning of the current results

    Directory of Open Access Journals (Sweden)

    Renato Moraes

    Full Text Available In southern Bahia, there are outcrops of migmatites and granulites in the Jequitinhonha Complex, which is part of the northern portion of the Araçuaí Orogen. Migmatites (garnet-cordierite diatexite dominate the metamorphic rocks and host lenses and layers of felsic garnet granulite. The conditions of temperature and pressure of metamorphism were calculated using conventional thermobarometry and the software THERMOCALC. Values around 850 °C and 7 kbar were obtained with THERMOCALC. The calculations for the garnet-cordierite diatexite were made considering aH2O equal to 1, but the best results of calculations for the granulites are obtained with aH2O values of 0.3. Pressure values obtained with GAPES resulted in consistent values with THERMOCALC, but the pair garnet-orthopyroxene always produces low values for temperature and high ones for pressure. The results are consistent with the presence of the pair garnet and cordierite in diatexite and orthopyroxene in felsic granulite. From the tectonic point of view, the setting in which metamorphism of these rocks occurred requires high heat flow with a thermal anomaly in mid continental crust, as indicated by values of 7 kbar. Recent studies have favored the closure of a back-arc basin for this tectonic setting, but it does not solve the problem that the time span between metamorphic peak and the end of granite intrusions, involving large bodies of charnockite, is more than 80 million years. The model of tectonic switching is suggested here as it can explain the maintenance of high temperatures for a more extended interval of time.

  18. Tectonic and climatic controls on fan systems: The Kohrud mountain belt, Central Iran

    Science.gov (United States)

    Jones, Stuart J.; Arzani, Nasser; Allen, Mark B.

    2014-04-01

    Late Pleistocene to Holocene fans of the Kohrud mountain belt (Central Iran) illustrate the problems of differentiating tectonic and climatic drivers for the sedimentary signatures of alluvial fan successions. It is widely recognised that tectonic processes create the topography that causes fan development. The existence and position of fans along the Kohrud mountain belt, NE of Esfahan, are controlled by faulting along the Qom-Zefreh fault system and associated fault zones. These faults display moderate amounts of historical and instrumental seismicity, and so may be considered to be tectonically active. However, fluvial systems on the fans are currently incising in response to low Gavkhoni playa lake levels since the mid-Holocene, producing incised gullies on the fans up to 30 m deep. These gullies expose an interdigitation of lake deposits (dominated by fine-grained silts and clays with evaporites) and coarse gravels that characterise the alluvial fan sediments. The boundaries of each facies are mostly sharp, with fan sediments superimposed on lake sediments with little to no evidence of reworking. In turn, anhydrite-glauberite, mirabilite and halite crusts drape over the gravels, recording a rapid return to still water, shallow ephemeral saline lake sedimentation. Neither transition can be explained by adjustment of the hinterland drainage system after tectonic uplift. The potential influence in Central Iran of enhanced monsoons, the northward drift of the Intertopical Convergence Zone (ITCZ) and Mediterranean climates for the early Holocene (~ 6-10 ka) point to episodic rainfall (during winter months) associated with discrete high magnitude floods on the fan surfaces. The fan sediments were deposited under the general influence of a highstand playa lake whose level was fluctuating in response to climate. This study demonstrates that although tectonism can induce fan development, it is the sensitive balance between aridity and humidity resulting from changes in

  19. LOWLID FORMATION AND PLATE TECTONICS ON EXOPLANETS

    Science.gov (United States)

    Stamenkovic, V.; Noack, L.; Breuer, D.

    2009-12-01

    The last years of astronomical observation have opened the doors to a universe filled with extrasolar planets. Detection techniques still only offer the possibility to detect mainly Super-Earths above five Earth masses. But detection techniques do steadily improve and are offering the possibility to detect even smaller planets. The observations show that planets seem to exist in many possible sizes just as the planets and moons of our own solar system do. It is only a natural question to ask if planetary mass has an influence on some key habitability factors such as on plate tectonics, allowing us to test which exoplanets might be more likely habitable than others, and allowing us to understand if plate tectonics on Earth is a stable or a critical, instable process that could easily be perturbed. Here we present results derived from 1D parameterized thermal evolution and 2D/3D computer models, showing how planetary mass influences the propensity of plate tectonics for planets with masses ranging from 0.1 to 10 Earth masses. Lately [2, 3] studied the effect of planetary mass on the ability to break plates and hence initiate plate tectonics - but both derived results contradictory to the other. We think that one of the reasons why both studies [2, 3] are not acceptable in their current form is partly due to an oversimplification. Both treated viscosity only temperature-dependent but neglected the effect pressure has on enlarging the viscosity in the deep mantle. More massive planets have therefore a stronger pressure-viscosity-coupling making convection at high pressures sluggish or even impossible. For planets larger than two Earth masses we observe that a conductive lid (termed low-lid) forms above the core-mantle boundary and thus reduces the effective convective part of the mantle when including a pressure-dependent term into the viscosity laws as shown in [1]. Moreover [2, 3] use time independent steady state models neglecting the fact that plate tectonics is a

  20. The alternative concept of global tectonics

    Science.gov (United States)

    Anokhin, Vladimir; Kholmyansky, Mikhael

    2016-04-01

    The existing plate tectonic paradigm becomes more questionable in relation to the new facts of the Earth. The most complete to date criticism of plate tectonics provisions contained in the article (Pratt, 2000). Authors can recall a few facts that contradict the idea of long-range movement of plates: - The absence of convection cells in the mantle, detected by seismic tomography; - The presence of long-lived deep regmatic network in the crust, not distorted by the movement of plates; - The inability of linking the global geometry of the of mutual long-distance movement of plates. All this gives reason to believe that correct, or at least a satisfactory concept of global tectonics are not exist now. After overcoming the usual inertia of thinking the plate paradigm in the foreseeable future will replace by different concept, more relevant as the observable facts of the Earth and the well-known physical laws. The authors suggest that currently accumulated sufficient volume of facts and theoretical ideas for the synthesis of a new general hypothesis of the structure and dynamics of the Earth. Analysis of the existing tectonic theory suggests that most of their provisions are mutually compatible. Obviously, plume tectonics perfectly compatible with any of classical models. It contradicts the only plate tectonics (movement of hot spots in principle not linked either with each other or with the general picture of the plate movements, the presence of mantle convection and mantle streams are mutually exclusive, and so on). The probable transfer of the heated material down up within the Earth may occur in various forms, the simplest of which (and, consequently, the most probable) are presented plumes. The existence in the mantle numerous large volumes of decompressed substances (detected seismic tomography), can be correlated with the bodies of plumes at different stages of uplift. Plumes who raise to the bottom of the lithosphere, to spread out to the sides and form a set

  1. Profiles for voltage-activated currents are multiphasic, not curvilinear

    CERN Document Server

    Nissen, Per

    2016-01-01

    Data for voltage-activation of a potassium channel (Matulef et al. Proc Natl Acad Sci USA 110: 17886-17891. 2013) were, as conventionally done, fitted by the authors by a Boltzmann function, i.e. by a curvilinear profile. Reanalysis of the data reveals however that this interpretation must be rejected in favor of a multiphasic profile, a series of straight lines separated by discontinuous transitions, quite often in the form of noncontiguities (jumps). In contrast to the generally very poor fits to the Boltzmann profiles, the fits to multiphasic profiles are very good. (For the four replicates, the average deviations from the Boltzmann curves were 10- to 100-fold larger than the deviations from the multiphasic profiles.) The difference in the median values was statistically highly significant, P<0.001 in most cases. For the mean values the deviations from the Boltzmann curve were 20-fold larger than the deviations from the multiphasic profile, and the difference in the median values was also highly signifi...

  2. Biological modulation of tectonics

    Science.gov (United States)

    Sleep, N. H.; Bird, D. K.

    2008-12-01

    Photosynthesis has had geologic consequences over the Earth's history. In addition to modifying Earth's atmosphere and ocean chemistry, it has also modulated tectonic processes through enhanced weathering and modification of the nature and composition of sedimentary rocks within fold mountain belts and convergent margins. Molecular biological studies indicate that bacterial photosynthesis evolved just once and that most bacterial clades descend from this photosynthetic common ancestor. Iron-based photosynthesis (ideally 4FeO + CO2 + H2O = 2Fe2O3 + CH2O) was the most bountiful anoxygenic niche on land. The back reaction provided energy to heterotrophic microbes and returned FeO to the photosynthetic microbes. Bacterial land colonists evolved into ecosystems that effectively weathered FeO-bearing minerals and volcanic glass. Clays, sands, and dissolved cations from the weathering process entered the ocean and formed our familiar classes sedimentary rocks: shales, sandstones, and carbonates. Marine photosynthesis caused organic carbon to accumulate in black shales. In contrast, non-photosynthetic ecosystems do not cause organic carbon to accumulate in shale. These evolutionary events occurred before 3.8 Ga as black shales are among the oldest rock types (Rosing and Frei, Earth Planet. Sci. Lett. 217, 237-244, 2004). Thick sedimentary sequences deformed into fold mountain belts. They remelted at depth to form granitic rocks (Rosing et al., Palaeoclimatol. Palaeoecol. 232, 99-11, 2006). Regions of outcropping low-FeO rocks including granites, quartzites, and some shales were a direct result. This dearth of FeO favored the evolution of oxic photosynthesis of cyanobacteria from photosynthetic soil bacteria. Black shales have an additional modulation effect on tectonics as they concentrate radioactive elements, particularly uranium (e.g. so that the surface heat flow varies by a factor of ca. 2). Thick sequences of black shales at continental rises of passive margins are

  3. Active tectonics on Deception Island (West-Antarctica): A new approach by using the fractal anisotropy of lineaments, fault slip measurements and the caldera collapse shape

    Science.gov (United States)

    Pérez-López, R.; Giner-Robles, J.L.; Martínez-Díaz, J.J.; Rodríguez-Pascua, M.A.; Bejar, M.; Paredes, C.; González-Casado, J.M.

    2007-01-01

    The tectonic field on Deception Island (South Shetlands, West Antarctica) is determined from structural and fractal analyses. Three different analyses are applied to the study of the strain and stress fields in the area: (1) field measurements of faults (strain analysis), (2) fractal geometry of the spatial distribution of lineaments and (3) the caldera shape (stress analyses). In this work, the identified strain field is extensional with the maximum horizontal shortening trending NE-SW and NW-SE. The fractal technique applied to the spatial distribution of lineaments indicates a stress field with SHMAX oriented NE-SW. The elliptical caldera of Deception Island, determined from field mapping, satellite imagery, vents and fissure eruptions, has an elongate shape and a stress field with SHMAX trending NE-SW.

  4. The Current Case of Quinolones: Synthetic Approaches and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Abdul Naeem

    2016-03-01

    Full Text Available Quinolones are broad-spectrum synthetic antibacterial drugs first obtained during the synthesis of chloroquine. Nalidixic acid, the prototype of quinolones, first became available for clinical consumption in 1962 and was used mainly for urinary tract infections caused by Escherichia coli and other pathogenic Gram-negative bacteria. Recently, significant work has been carried out to synthesize novel quinolone analogues with enhanced activity and potential usage for the treatment of different bacterial diseases. These novel analogues are made by substitution at different sites—the variation at the C-6 and C-8 positions gives more effective drugs. Substitution of a fluorine atom at the C-6 position produces fluroquinolones, which account for a large proportion of the quinolones in clinical use. Among others, substitution of piperazine or methylpiperazine, pyrrolidinyl and piperidinyl rings also yields effective analogues. A total of twenty six analogues are reported in this review. The targets of quinolones are two bacterial enzymes of the class II topoisomerase family, namely gyrase and topoisomerase IV. Quinolones increase the concentration of drug-enzyme-DNA cleavage complexes and convert them into cellular toxins; as a result they are bactericidal. High bioavailability, relative low toxicity and favorable pharmacokinetics have resulted in the clinical success of fluoroquinolones and quinolones. Due to these superior properties, quinolones have been extensively utilized and this increased usage has resulted in some quinolone-resistant bacterial strains. Bacteria become resistant to quinolones by three mechanisms: (1 mutation in the target site (gyrase and/or topoisomerase IV of quinolones; (2 plasmid-mediated resistance; and (3 chromosome-mediated quinolone resistance. In plasmid-mediated resistance, the efflux of quinolones is increased along with a decrease in the interaction of the drug with gyrase (topoisomerase IV. In the case of

  5. The Current Case of Quinolones: Synthetic Approaches and Antibacterial Activity.

    Science.gov (United States)

    Naeem, Abdul; Badshah, Syed Lal; Muska, Mairman; Ahmad, Nasir; Khan, Khalid

    2016-03-28

    Quinolones are broad-spectrum synthetic antibacterial drugs first obtained during the synthesis of chloroquine. Nalidixic acid, the prototype of quinolones, first became available for clinical consumption in 1962 and was used mainly for urinary tract infections caused by Escherichia coli and other pathogenic Gram-negative bacteria. Recently, significant work has been carried out to synthesize novel quinolone analogues with enhanced activity and potential usage for the treatment of different bacterial diseases. These novel analogues are made by substitution at different sites--the variation at the C-6 and C-8 positions gives more effective drugs. Substitution of a fluorine atom at the C-6 position produces fluroquinolones, which account for a large proportion of the quinolones in clinical use. Among others, substitution of piperazine or methylpiperazine, pyrrolidinyl and piperidinyl rings also yields effective analogues. A total of twenty six analogues are reported in this review. The targets of quinolones are two bacterial enzymes of the class II topoisomerase family, namely gyrase and topoisomerase IV. Quinolones increase the concentration of drug-enzyme-DNA cleavage complexes and convert them into cellular toxins; as a result they are bactericidal. High bioavailability, relative low toxicity and favorable pharmacokinetics have resulted in the clinical success of fluoroquinolones and quinolones. Due to these superior properties, quinolones have been extensively utilized and this increased usage has resulted in some quinolone-resistant bacterial strains. Bacteria become resistant to quinolones by three mechanisms: (1) mutation in the target site (gyrase and/or topoisomerase IV) of quinolones; (2) plasmid-mediated resistance; and (3) chromosome-mediated quinolone resistance. In plasmid-mediated resistance, the efflux of quinolones is increased along with a decrease in the interaction of the drug with gyrase (topoisomerase IV). In the case of chromosome

  6. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    Science.gov (United States)

    Ry, Rexha Verdhora; Nugraha, Andri Dian

    2015-04-01

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger's method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger's result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location.

  7. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    Energy Technology Data Exchange (ETDEWEB)

    Ry, Rexha Verdhora, E-mail: rexha.vry@gmail.com [Master Program of Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha No.10, Bandung 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Research Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha No.10, Bandung 40132 (Indonesia)

    2015-04-24

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger’s method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger’s result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location.

  8. Hysteresis Current Control technique based on Space Vector Modulation for Active Power Filter

    Directory of Open Access Journals (Sweden)

    Wang Yun-liang

    2011-09-01

    Full Text Available In this paper, the hysteresis current control (HCC technique based on space vector modulation (SVM for shunt active power filter (APF is proposed. The switching control algorithms of the HCC based SVM manage to generate compensated current according to the reference current. Harmonics extraction is based on the instantaneous active and reactive power theorem in time domain by calculating the power compensation. A closed loop control system is carried out and the error current is the difference between the reference current which is obtained from the power compensation and the actual current needs to be injected back into the power grid. By implementing this control strategy, the APF manages to generate better compensated harmonics currents to the power grid. Keywords: active power filter, hysteresis current control, space vector modulation ,matlab/simulink

  9. Dysfunctional amygdala activation and connectivity with the prefrontal cortex in current cocaine users

    NARCIS (Netherlands)

    Crunelle, C.L.; Kaag, A.M.; Munkhof, H.E. van den; Reneman, L.; Homberg, J.R.; Sabbe, B.; Brink, W. van den; Wingen, G. van

    2015-01-01

    OBJECTIVES: Stimulant use is associated with increased anxiety and a single administration of dexamphetamine increases amygdala activation to biologically salient stimuli in healthy individuals. Here, we investigate how current cocaine use affects amygdala activity and amygdala connectivity with the

  10. Tectonics: Changing of the plates

    Science.gov (United States)

    Brandon, Alan

    2016-10-01

    The composition of Earth's crust depends on the style of plate tectonics and of the melting regimes in the mantle. Analyses of the oldest identified rocks suggest that these styles and the resulting crust have changed over Earth's history.

  11. Navigating Towards Digital Tectonic Tools

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due; Kirkegaard, Poul Henning

    2006-01-01

    like opposites, the term tectonics deals with creating a meaningful relationship between the two. The aim of this paper is to investigate what a digital tectonic tool could be and what relationship with technology it should represent. An understanding of this relationship can help us not only...... to understand the conflicts in architecture and the building industry but also bring us further into a discussion of how architecture can use digital tools. The investigation is carried out firstly by approaching the subject theoretically through the term tectonics and by setting up a model of the values...... a tectonic tool should encompass. Secondly the ability and validity of the model are shown by applying it to a case study of Jørn Utzon’s work on Minor Hall in Sydney Opera House - for the sake of exemplification the technical field focused on in this paper is room acoustics. Thirdly the relationship between...

  12. History and Evolution of Precambrian plate tectonics

    Science.gov (United States)

    Fischer, Ria; Gerya, Taras

    2014-05-01

    Plate tectonics is a global self-organising process driven by negative buoyancy at thermal boundary layers. Phanerozoic plate tectonics with its typical subduction and orogeny is relatively well understood and can be traced back in the geological records of the continents. Interpretations of geological, petrological and geochemical observations from Proterozoic and Archean orogenic belts however (e.g., Brown, 2006), suggest a different tectonic regime in the Precambrian. Due to higher radioactive heat production the Precambrian lithosphere shows lower internal strength and is strongly weakened by percolating melts. The fundamental difference between Precambrian and Phanerozoic tectonics is therefore the upper-mantle temperature, which determines the strength of the upper mantle (Brun, 2002) and the further tectonic history. 3D petrological-thermomechanical numerical modelling experiments of oceanic subduction at an active plate at different upper-mantle temperatures show these different subduction regimes. For upper-mantle temperatures buckling and also lithospheric delamination and drip-offs. For upper-mantle temperatures > 250 K above the present day value no subduction occurs any more. The whole lithosphere is delaminating and due to strong volcanism and formation of a thicker crust subduction is inhibited. This stage of 200-250 K higher upper mantle temperature which corresponds roughly to the early Archean (Abbott, 1994) is marked by strong volcanism due to sublithospheric decompression melting which leads to an equal thickness for both oceanic and continental plates. As a consequence subduction is inhibited, but a compressional setup instead will lead to orogeny between a continental or felsic terrain and an oceanic or mafic terrain as well as internal crustal convection. Small-scale convection with plume shaped cold downwellings also in the upper mantle is of increased importance compared to the large-scale subduction cycle observed for present temperature

  13. Tectonic field and deformation in Chalkidiki area, Greece

    Science.gov (United States)

    Alatza, Stavroula-Drosoula; Marinou, Aggeliki; Anastasiou, Demitris; Papanikolaou, Xanthos; Paradissis, Demitris

    2015-04-01

    Greece is situated on the convergence limits, between the Eurasian and the African lithospheric plate, and as a consequence, is considered as one of the most seismogenic areas on the world. Chalkidiki is part of the region of Central Macedonia in Northen Greece. The region of Chalkidiki is traversed by three faults and it is an area of great tectonic interest. On a daily basis, earthquakes occur in the seabed between the three peninsulas of Chalkidiki. Concerning the geomorphology of the area, it is covered by three types of rocks, the Serbomacedonian mass, the Perirodopiki zone and Peonia sub zone. The contact with the Serbomacedonian mass has a direct effect on tectonics of the region, since the area has a continuous tectonic activity. The neotectonic activity is characterized by normal faults, as well as horns and tectonic trenches. Velocity field and strain parameters for a deformation model are evaluated using GPS data from a geodetic network of thirty one points established in the broader area of Chalkidiki. Apart from these points, all the available observations of permanent stations in the area, were used to determine the final tectonic velocity field. All data were processed using Bernese GNSS Software v.5. The implementation of the reference system ITRF2005, was performed, using nine IGS stations, for the local network. Time series analysis for each point was used, in order to calculate the displacements and tectonic velocities. Finally, in order to investigate the strain patterns of the area, strain tensors were computed and discussed.

  14. Thoughts on studies of China continental geology and tectonics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guowei; GUO Anli; YAO Anping

    2006-01-01

    As an important part of the global continents, China continent has long been situated in the peculiar tectonic position and experienced extremely complicated activities, which resulted in the regional unique characteristics for China continent on the global common geological background. These characteristics contain abundant information regarding scientific key issues of modern geological frontier. Thus, China continent can be a natural laboratory and excellent arena for the modern geosciences. The modern earth sciences have started entering the era featured with earth systematic science and beyond plate tectonics. How to take the regional advantage and exploit the treasure resource to participate the new theoretical and methodological creation is a historic opportunity and great challenge we are facing. This paper generalizes research priorities in four fields on China continental geology and tectonics for discussion. They are: China continental tectonics and dynamics; Mesozoic-Cenozoic crustal deformation and deep-seated processes in China continent and the adjacent regions; deep-seated dynamic background and evolutionary trend of crustal tectonic activities on the time scale of human existence; deepseated background and processes of conjunction and transformation of different tectonic systems.

  15. Optimal Planet Properties For Plate Tectonics Through Time And Space

    Science.gov (United States)

    Stamenkovic, Vlada; Seager, Sara

    2014-11-01

    Both the time and the location of planet formation shape a rocky planet’s mass, interior composition and structure, and hence also its tectonic mode. The tectonic mode of a planet can vary between two end-member solutions, plate tectonics and stagnant lid convection, and does significantly impact outgassing and biogeochemical cycles on any rocky planet. Therefore, estimating how the tectonic mode of a planet is affected by a planet’s age, mass, structure, and composition is a major step towards understanding habitability of exoplanets and geophysical false positives to biosignature gases. We connect geophysics to astronomy in order to understand how we could identify and where we could find planet candidates with optimal conditions for plate tectonics. To achieve this goal, we use thermal evolution models, account for the current wide range of uncertainties, and simulate various alien planets. Based on our best model estimates, we predict that the ideal targets for plate tectonics are oxygen-dominated (C/O<1) (solar system like) rocky planets of ~1 Earth mass with surface oceans, large metallic cores super-Mercury, rocky body densities of ~7000kgm-3), and with small mantle concentrations of iron 0%), water 0%), and radiogenic isotopes 10 times less than Earth). Super-Earths, undifferentiated planets, and especially hypothetical carbon planets, speculated to consist of SiC and C, are not optimal for the occurrence of plate tectonics. These results put Earth close to an ideal compositional and structural configuration for plate tectonics. Moreover, the results indicate that plate tectonics might have never existed on planets formed soon after the Big Bang—but instead is favored on planets formed from an evolved interstellar medium enriched in iron but depleted in silicon, oxygen, and especially in Th, K, and U relative to iron. This possibly sets a belated Galactic start for complex Earth-like surface life if plate tectonics significantly impacts the build up

  16. Study of the metamorphic belts and tectonics; Henseitai kenkyu to tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T. [Hokkaido University, Sapporo (Japan)

    1997-10-25

    Study of metamorphic belts and tectonics is introduced. Minerals supposedly originating in the transitional zone and the lower mantle, that is, inclusions in diamond in kimberlite, are deemed to carry information about the depth level of 670km and lower. The place of origin of peridotite, Alpe Arami of Switzerland, is again estimated at a level of 300km or deeper. In the tectonic cross section in this region, the oceanic crust is bent and folded, and such a structure enables the supposition that fragments off the transitional zone may be carried upward to the ground surface. This region is now being limelighted, with plume tectonics enjoying popularity. The split of Pangaea is related with the ascent of plume. In the eastern part of Australia, there are alkali rocks attributable to the plume that was supposedly active at the end of the Proterozoic. Zircon U-Pb dating by SHRIMP offers a new approach to the tectonics of metamorphic rocks, and is reinforcing the position of metamorphic petrology relative to the study of collision and split of continents. 64 refs., 10 figs.

  17. Late Quaternary river channel migrations of the Kura River in Transcaucasia - tectonic versus climatic causes

    Science.gov (United States)

    von Suchodoletz, Hans; Gärtner, Andreas; Hoth, Silvan; Umlauft, Josefine; Godoladze, Tea; Faust, Dominik

    2015-04-01

    Large-scale river channel migrations either in the form of avulsions or combing, i.e. progressive lateral migrations, are global phenomena during the Late Quaternary. Such channel migrations were triggered by tectonics, climate change, human activity or a combination of those factors. River channel migrations have the potential to cause significant human and economic losses. Thus, a more thorough knowledge about underlying causes and process rates is essential. Furthermore, such studies will elucidate the sensitivity or robustness of rivers to different external and internal forcing-agents, i.e. they help to identify the dominant drivers of regional landscape evolution. The Caucasus region is part of the active collision zone between the Africa-Arabian and the Eurasian plates, and is characterized by high current tectonic activity. Furthermore, significant environmental changes took place during the Late Quaternary, i.e. the shrinking or even disappearance of glaciers in the Greater and Lesser Caucasus or fundamental changes of the vegetation cover varying between woodland and grassland-dominated vegetation. The Kura River is the main gaining stream of the Transcaucasian Depression located between the Greater Caucasus Mountains in the north and the Lesser Caucasus Mountains in the south, and receives several tributaries from both mountain ranges. This study focusses on the middle course of the Kura River in eastern Georgia, SE of the city of Tbilisi. Integration of fluvial geomorphology, geochronology, heavy mineral analyses and seismo-tectonic analyses demonstrates that this part of the Kura River underwent large-scale channel migrations up to >10 km during Late Pleistocene and Holocene. It is interpreted that these movements followed both tectonic and climatic triggers: Whereas SW-ward migrations were caused by tectonic uplift in and SW-directed advance of the Kura fold and thrust belt as part of the Greater Caucasus, NE-ward migrations occurred during cold

  18. Fractal Tectonics and Erosion

    Science.gov (United States)

    Turcotte, Donald L.

    Tectonic processes build landforms that are subsequently destroyed by erosional processes. Landforms exhibit fractal statistics in a variety of ways; examples include (1) lengths of coast lines; (2) number-size statistics of lakes and islands; (3) spectral behavior of topography and bathymetry both globally and locally; and (4) branching statistics of drainage networks. Erosional processes are dominant in the development of many landforms on this planet, but similar fractal statistics are also applicable to the surface of Venus where minimal erosion has occurred. A number of dynamical systems models for landforms have been proposed, including (1) cellular automata; (2) diffusion limited aggregation; (3) self-avoiding percolation; and (4) advective-diffusion equations. The fractal statistics and validity of these models will be discussed. Earthquakes also exhibit fractal statistics. The frequency-magnitude statistics of earthquakes satisfy the fractal Gutenberg-Richter relation both globally and locally. Earthquakes are believed to be a classic example of self-organized criticality. One model for earthquakes utilizes interacting slider-blocks. These slider block models have been shown to behave chaotically and to exhibit self-organized criticality. The applicability of these models will be discussed and alternative approaches will be presented. Fragmentation has been demonstrated to produce fractal statistics in many cases. Comminution is one model for fragmentation that yields fractal statistics. It has been proposed that comminution is also responsible for much of the deformation in the earth's crust. The brittle disruption of the crust and the resulting earthquakes present an integrated problem with many fractal aspects.

  19. Planetary Geophysics and Tectonics

    Science.gov (United States)

    Zuber, Maria

    2005-01-01

    The broad objective of this work is to improve understanding of the internal structures and thermal and stress histories of the solid planets by combining results from analytical and computational modeling, and geophysical data analysis of gravity, topography and tectonic surface structures. During the past year we performed two quite independent studies in the attempt to explain the Mariner 10 magnetic observations of Mercury. In the first we revisited the possibility of crustal remanence by studying the conditions under which one could break symmetry inherent in Runcorn's model of a uniformly magnetized shell to produce a remanent signal with a dipolar form. In the second we applied a thin shell dynamo model to evaluate the range of intensity/structure for which such a planetary configuration can produce a dipole field consistent with Mariner 10 results. In the next full proposal cycle we will: (1) develop numerical and analytical and models of thin shell dynamos to address the possible nature of Mercury s present-day magnetic field and the demise of Mars magnetic field; (2) study the effect of degree-1 mantle convection on a core dynamo as relevant to the early magnetic field of Mars; (3) develop models of how the deep mantles of terrestrial planets are perturbed by large impacts and address the consequences for mantle evolution; (4) study the structure, compensation, state of stress, and viscous relaxation of lunar basins, and address implications for the Moon s state of stress and thermal history by modeling and gravity/topography analysis; and (5) use a three-dimensional viscous relaxation model for a planet with generalized vertical viscosity distribution to study the degree-two components of the Moon's topography and gravity fields to constrain the primordial stress state and spatial heterogeneity of the crust and mantle.

  20. Ground subsidence and associated ground fracturing in urban areas: InSAR monitoring of active tectonic structures (Ciudad Guzman, Colima Graben - Mexico)

    Science.gov (United States)

    Bignami, C.; Brunori, C.; Zucca, F.; Groppelli, G.; Norini, G.; Hernandez, N. D.; Stramondo, S.

    2013-12-01

    This study focuses on the observation of a creeping phenomenon that produces subsidence of the Zapotlan basin and ground fracturing in correspondence of the Ciudad Guzmàn (Jalisco - Mexico). The September 21, 2012, the Ciudad Guzmàn has been struck by a phenomenon of ground fracturing of about 1.5 km of length. This event caused the deformation of the roads and the damage of 30 houses, of which eight have been declared uninhabitable. The alignment of fractures is coincident with the escarpments produced in September 19, 1985, in the Ciudad Guzman urban area, when a strong earthquake, magnitude 8.1, struck the Mexican area, causing the deaths of at least 10,000 people and serious damage in Mexico City. In Ciudad Guzmán, about 60% of the buildings were destroyed, with about 50 loss of life. The city is located in the Zapotlan basin (northern Colima graben), a wide tectonic depression where the depth of the infilling sediments is about 1 km. This subsidence cannot be measured outside the urbanized area, but it can be considered as a deformation mechanism of the central part of the basin. In order to detect and mapping the spatio-temporal features of the processes that led to this event, we applied InSAR multi-temporal techniques to analyze a dataset of ENVISAT satellite SAR images, acquired in a time span between 2003-2010. InSAR techniques detect a subsidence of the north-western part of Ciudad Guzmàn of about 15 mm/yr in the time interval 2003-2010. The displacement occurred in September 21, 2012, was detected using two RadarSAT2 acquisitions (2012-03-22 and 2013-03-17). The explanation of surface movements based on interferometric results, ground data and geological field observations, allowed confirming surface effect due to the overexploitation of the aquifers and highlights a subsidence due to anthropogenic causes coupled to buried tectonic structures.

  1. Identifying tectonic parameters that influence tsunamigenesis

    Science.gov (United States)

    van Zelst, Iris; Brizzi, Silvia; van Dinther, Ylona; Heuret, Arnauld; Funiciello, Francesca

    2017-04-01

    The role of tectonics in tsunami generation is at present poorly understood. However, the fact that some regions produce more tsunamis than others indicates that tectonics could influence tsunamigenesis. Here, we complement a global earthquake database that contains geometrical, mechanical, and seismicity parameters of subduction zones with tsunami data. We statistically analyse the database to identify the tectonic parameters that affect tsunamigenesis. The Pearson's product-moment correlation coefficients reveal high positive correlations of 0.65 between, amongst others, the maximum water height of tsunamis and the seismic coupling in a subduction zone. However, these correlations are mainly caused by outliers. The Spearman's rank correlation coefficient results in more robust correlations of 0.60 between the number of tsunamis in a subduction zone and subduction velocity (positive correlation) and the sediment thickness at the trench (negative correlation). Interestingly, there is a positive correlation between the latter and tsunami magnitude. In an effort towards multivariate statistics, a binary decision tree analysis is conducted with one variable. However, this shows that the amount of data is too scarce. To complement this limited amount of data and to assess physical causality of the tectonic parameters with regard to tsunamigenesis, we conduct a numerical study of the most promising parameters using a geodynamic seismic cycle model. We show that an increase in sediment thickness on the subducting plate results in a shift in seismic activity from outerrise normal faults to splay faults. We also show that the splay fault is the preferred rupture path for a strongly velocity strengthening friction regime in the shallow part of the subduction zone, which increases the tsunamigenic potential. A larger updip limit of the seismogenic zone results in larger vertical surface displacement.

  2. Analysis of the seismicity of Southeastern Sicily: a proposed tectonic interpretation

    Directory of Open Access Journals (Sweden)

    M. S. Barbano

    2000-06-01

    Full Text Available Southeastern Sicily is one of the Italian regions with high seismic risk and is characterised by the occurrence in the past of large destructive events (MS = 6.4-7.3 over a territory which is densely urbanised today. The main earthquakes were analysed and some minor damaging shocks reviewed to investigate the main seismogenic features of the region. The comparison between the pattern of seismicity and evidence of Quaternary tectonics allowed us to propose a first tentative, tectonic interpretation of the earthquakes. On the whole, the seismicity of SE Sicily seems distributed along regional fault systems which have had a role in the recent geodynamic evolution of the area. The Malta escarpment, the only structure whose late Quaternary-recent activity is currently known, appears the most probable source for earthquakes with about 7 magnitude. Although no evidence of tectonics subsequent to the middle Pleistocene is available for them, the Scicli line and the NE-SW fault system delimiting the northern sector of the Hyblean plateau seem seismically active with events with maximum magnitude of 5.2 and 6.4, respectively.

  3. Relationship between plume and plate tectonics

    Science.gov (United States)

    Puchkov, V. N.

    2016-07-01

    The relationship between plate- and plume-tectonics is considered in view of the growth and breakdown of supercontinents, active rifting, the formation of passive volcanic-type continental margins, and the origin of time-progressive volcanic chains on oceanic and continental plates. The mantle wind phenomenon is described, as well as its effect on plume morphology and anisotropy of the ambient mantle. The interaction of plumes and mid-ocean ridges is discussed. The principles and problems of plume activity analysis in subduction- and collision-related foldbelts are considered and illustrated with examples.

  4. Activation processes on GaAs photocathode by different currents of oxygen source

    Science.gov (United States)

    Miao, Zhuang; Shi, Feng; Cheng, Hongchang; Wang, Shufei; Zhang, Xiaohui; Yuan, Yuan; Chen, Chang

    2015-04-01

    In order to know the influence of activation processes on GaAs photocathodes, three GaAs samples were activated by a fixed current of cesium source and different currents of oxygen source. The current of caesium source is same during activation to ensure initial adsorption of caesium quantum is similar, which is the base to show the difference during alternation activation of caesium and oxygen. Analysed with the activation data, it is indicated that Cs-to-O current ratio of 1.07 is the optimum ratio to obtain higher sensitivity and better stability. According to double dipole model, stable and uniform double dipole layers of GaAs-O-Cs:Cs-O-Cs are formed and negative electron affinity is achieved on GaAs surface by activation with cesium and oxygen. The analytical result is just coincident with the model. Thus there is an efficient technological method to improve sensitivity and stability of GaAs photocathode.

  5. Plate Margin Deformation and Active Tectonics Along the Northern Edge of the Yakutat Terrane in the Saint Elias Orogen, Alaska and Yukon, Canada

    Science.gov (United States)

    Bruhn, Ronald L.; Sauber, Jeanne; Cotton, Michele M.; Pavlis, Terry L.; Burgess, Evan; Ruppert, Natalia; Forster, Richard R.

    2012-01-01

    The northwest directed motion of the Pacific plate is accompanied by migration and collision of the Yakutat terrane into the cusp of southern Alaska. The nature and magnitude of accretion and translation on upper crustal faults and folds is poorly constrained, however, due to pervasive glaciation. In this study we used high-resolution topography, geodetic imaging, seismic, and geologic data to advance understanding of the transition from strike-slip motion on the Fairweather fault to plate margin deformation on the Bagley fault, which cuts through the upper plate of the collisional suture above the subduction megathrust. The Fairweather fault terminates by oblique-extensional splay faulting within a structural syntaxis, allowing rapid tectonic upwelling of rocks driven by thrust faulting and crustal contraction. Plate motion is partly transferred from the Fairweather to the Bagley fault, which extends 125 km farther west as a dextral shear zone that is partly reactivated by reverse faulting. The Bagley fault dips steeply through the upper plate to intersect the subduction megathrust at depth, forming a narrow fault-bounded crustal sliver in the obliquely convergent plate margin. Since . 20 Ma the Bagley fault has accommodated more than 50 km of dextral shearing and several kilometers of reverse motion along its southern flank during terrane accretion. The fault is considered capable of generating earthquakes because it is linked to faults that generated large historic earthquakes, suitably oriented for reactivation in the contemporary stress field, and locally marked by seismicity. The fault may generate earthquakes of Mw <= 7.5.

  6. Stress drops of induced and tectonic earthquakes in the central United States are indistinguishable.

    Science.gov (United States)

    Huang, Yihe; Ellsworth, William L; Beroza, Gregory C

    2017-08-01

    Induced earthquakes currently pose a significant hazard in the central United States, but there is considerable uncertainty about the severity of their ground motions. We measure stress drops of 39 moderate-magnitude induced and tectonic earthquakes in the central United States and eastern North America. Induced earthquakes, more than half of which are shallower than 5 km, show a comparable median stress drop to tectonic earthquakes in the central United States that are dominantly strike-slip but a lower median stress drop than that of tectonic earthquakes in the eastern North America that are dominantly reverse-faulting. This suggests that ground motion prediction equations developed for tectonic earthquakes can be applied to induced earthquakes if the effects of depth and faulting style are properly considered. Our observation leads to the notion that, similar to tectonic earthquakes, induced earthquakes are driven by tectonic stresses.

  7. 月球仍然活跃的构造、火成和内部特征等证据%Evidence for Recent Lunar Tectonic, Volcanic and Interior Activity

    Institute of Scientific and Technical Information of China (English)

    Clive NEAL; 平劲松

    2014-01-01

    月球尽管被作为类地行星演化的最终形态的代表,被认为在25亿年前已经完全冷却,根据阿波罗时代以来、特别是近十余年的月球轨道器和着陆器获得的关于月球构造、火成活动、月震和内部结构等多种证据,表明月球从深层内部到表面仍然活跃,尚未彻底冷却“死亡”。这将完全改变人们关于月球演化历史和状态的观念。%The Moon,which was believed that died out about 2.5 ~ 3.5 billion years ago with volcanic and tectonic activity had essentially ceased by 2.5 Ga.,represents an end member in terms of terrestrial planet evolution in the inner Solar System.However,the Apollo data,especially coupled with the new data of the Moon about lunar tectonic,volcanic,moonquake and interior structure obtained by lunar orbiters and landers during the past dozen years,shows evidence that suggests the Moon remained active from deep interior to the surface,and by no means of died out totally.This will change our view of the lunar evolution history and status.

  8. Modulatory effect of substance P on GABA-activated currents from rat dorsal root ganglion

    Institute of Scientific and Technical Information of China (English)

    Jun-qiang SI; Zhi-qin ZHANG; Chun-xia LI; Li-feng WANG; Yun-lei YANG; Zhi-wang LI

    2004-01-01

    AIM: To explore the modulatory effect of substance P (SP) on GABA-activated current of dorsal root ganglion (DRG) neurons in rat. METHODS: The whole-cell patch-clamp technique was used to record SP- and GABAactivated currents in neurons freshly dissociated from rat DRG neurons. Drugs were applied by rapid solution exchange. RESULTS: Application of SP (28/41, 68.5 %) and GABA (36/41, 88.2 %) could induce concentrationdependent inward current in some cells. SP-(10 μmol/L) and GABA (100 μmol/L)-activated inward currents were (244±83) pA (n=9) and (1.8±0.5) nA (n=13), respectively. The majority of GABA-activated current had obvious three processes, the peak value (Ip), the steady state (Iss) and the desensitization (Ia). The desensitization of GABAactivated current was a biphasic process, including fast and slow desensitization. However, pre-application of SP (0.001-1 μmol/L) could inhibit the GABA-activated inward current which was identified to be GABAA receptormediated current. The inhibitory effects were concentration-dependent. The inhibitory effect of SP on the peak value of GABA-activated current was more than the steady state of GABA-activated current. The inhibition of GABA-activated current by SP (0.1 μmol/L) was related to the time after application of SP, the inhibition of GABAactivated currents by SP reached the peak at about 4 min (49.8 %±7.2 %, n=7, P<0.01) and took about 12 min to get a full recovery. The inhibition of GABA-activated currents by SP was almost completely removed after blockade of PKC by H-7 with the re-patch clamp. CONCLUSION: Pre-application of SP exerts a more strong inhibitory effect on the peak value of GABA-activated current than the steady state of GABA-activated current.

  9. Photonic Network R&D Activities in Japan-Current Activities and Future Perspectives

    Science.gov (United States)

    Kitayama, Ken-Ichi; Miki, Tetsuya; Morioka, Toshio; Tsushima, Hideaki; Koga, Masafumi; Mori, Kazuyuki; Araki, Soichiro; Sato, Ken-Ichi; Onaka, Hiroshi; Namiki, Shu; Aoyama, Tomonori

    2005-10-01

    R&D activities on photonic networks in Japan are presented. First, milestones in current ongoing R&D programs supported by Japanese government agencies are introduced, including long-distance and wavelength division multiplexing (WDM) fiber transmission, wavelength routing, optical burst switching (OBS), and control-plane technology for IP backbone networks. Their goal was set to evolve a legacy telecommunications network to IP-over-WDM networks by introducing technologies for WDM and wavelength routing. We then discuss the perspectives of so-called PHASE II R&D programs for photonic networks over the next 5 years until 2010, by focusing on the report that has been recently issued by the Photonic Internet Forum (PIF), a consortium that has major carriers, telecom vendors, and Japanese academics as members. The PHASE II R&D programs should serve to establish a photonic platform to provide abundant bandwidth on demand, at any time on a real-time basis, through the customer's initiative to promote bandwidth-rich applications, such as grid computing, real-time digital-cinema streaming, medical and educational applications, and network storage in e-commerce.

  10. Principal component analysis of Birkeland currents determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    Science.gov (United States)

    Milan, S. E.; Carter, J. A.; Korth, H.; Anderson, B. J.

    2015-12-01

    Principal component analysis is performed on Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment. Principal component analysis (PCA) identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The regions 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns.

  11. Principle Component Analysis of Birkeland Currents Determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    Science.gov (United States)

    Milan, S. E.; Carter, J. A.; Korth, H.; Anderson, B. J.

    2015-12-01

    Principle Component Analysis is performed on northern and southern hemisphere Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). PCA identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The region 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly-reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns. Other interhemispheric differences are discussed.

  12. Principal component analysis of Birkeland currents determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    CERN Document Server

    Milan, S E; Korth, H; Anderson, B J

    2016-01-01

    Principal component analysis is performed on Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment. Principal component analysis (PCA) identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The regions 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns.

  13. Barrel organ of plate tectonics - a new tool for outreach and education

    Science.gov (United States)

    Broz, Petr; Machek, Matěj; Šorm, Zdar

    2016-04-01

    Plate tectonics is the major geological concept to explain dynamics and structure of Earth's outer shell, the lithosphere. In the plate tectonic theory processes in the Earth lithosphere and its dynamics is driven by the relative motion and interaction of lithospheric plates. Geologically most active regions on Earth often correlate with the lithospheric plate boundaries. Thus for explaining the earth surface evolution, mountain building, volcanism and earthquake origin it is important to understand processes at the plate boundaries. However these processes associated with plate tectonics usually require significant period of time to take effects, therefore, their entire cycles cannot be directly observed in the nature by humans. This makes a challenge for scientists studying these processes, but also for teachers and popularizers trying to explain them to students and to the general public. Therefore, to overcome this problem, we developed a mechanical model of plate tectonics enabling demonstration of most important processes associated with plate tectonics in real time. The mechanical model is a wooden box, more specifically a special type of barrel organ, with hand painted backdrops in the front side. These backdrops are divided into several components representing geodynamic processes associated with plate tectonics, specifically convective currents occurring in the mantle, sea-floor spreading, a subduction of the oceanic crust under the continental crust, partial melting and volcanism associated with subduction, a formation of magmatic stripes, an ascent of mantle plume throughout the mantle, a volcanic activity associated with hot spots, and a formation and degradation of volcanic islands on moving lithospheric plate. All components are set in motion by a handle controlled by a human operator, and the scene is illuminated with colored lights controlled automatically by an electric device embedded in the box. Operation of the model may be seen on www

  14. Study of tectonic layering motion and layering mineralization in the Tongling metallogenic cluster

    Institute of Scientific and Technical Information of China (English)

    吴淦国; 张达; 臧文拴

    2003-01-01

    Analysis of the deep tectonics and cover tectonic deformations shows that tectonic layering motion is a typical lithospheric characteristic in the Tongling area and the metallogenic belt of the middle-lower Yangtze. Controlling of the deep tectonosphere over the shallow-seated tectonosphere involves various grades of tectonic layering motions. Multi-layer, multi-grade, and multi-directional gliding tectonics are the specific modes of tectonic layering motions in the cover of the Tongling metallogenic cluster. The gliding tectonics developed based on S-shaped folds of the Indosinian, and was continuously active in the Yanshanian. They correspond to the deformation systems of the EW and NNE extensions. The control of tectonic layering motion acts against ore-forming processes, the different interlayer gliding belts can easily form different genetic-type deposits, and the ore-forming features of different parts of the same gliding layer are different. All of these characters are closely related to tectonic gliding mechanisms, tectonic compounding characteristics, features of metallogenic wall rocks, and types of ore-forming hydrothermal solutions.

  15. Current status of neutron activation analysis using the Dalat Nuclear Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Van Suc; Nguyen Mong Sinh [Nuclear Research Institute, Dalat (Viet Nam)

    1999-10-01

    Neutron activation analysis is one of the most sensitive, rapid, accurated methods for determination of trace elements in different materials. A review is made of the current status of the activities and the results in studying and developing NAA (Neutron Activation Analysis) at the Dalat Nuclear Research Institute and applying this method to different sectors of science and technology in Vietnam. (author)

  16. A NEW METHOD TO CALCULATE COMPENSATION CURRENT IN PARALLEL ACTIVE POWER FILTER

    Directory of Open Access Journals (Sweden)

    Ahmet ALTINTAŞ

    2004-03-01

    Full Text Available Nowadays, active power filter plays an important role in reducing harmonic current and reactive power in power lines. The reliability and effectiveness of an active power filter depends basically on three characteristics. These are the modulation method, the design characteristics of the PWM modulator and the method implemented to generate compensation current. For the last one, there are many proposed methods. Most of them complicated and hence difficult to implement and adjust. In this study, a new method to calculate compensation current is improved and tested in single-phase parallel active power filter controlled by microcontroller. Experimental and simulation results are presented in the paper.

  17. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  18. The Tectonic Potentials of Concrete

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole

    2013-01-01

    with the industrial paradigm of standardization, have been put forward. This development is carried forward by computers and digital fabrication, but has yet to find its way into the production of building components. With regards to concrete casting, however, existing research do offer advancement towards...... of geometric forms in concrete. The former was referred to as mould tectonics, the latter concrete tectonics. A study of the concepts of ‘New Production Philosophy’, ‘Mass-customization’, and Digital Tectonics is presented as a basis for investigating their use in concrete casting. Digital modelling....... However, a single concrete casting material, given the use of the right technique that is able to address all these problems, has not been identified, neither in state-of-the-art nor in the case studies. It follows that due to today’s demands for resource optimization and competitiveness it is unlikely...

  19. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  20. Selective regulation of current densities underlies spontaneous changes in the activity of cultured neurons.

    Science.gov (United States)

    Turrigiano, G; LeMasson, G; Marder, E

    1995-05-01

    We study the electrical activity patterns and the expression of conductances in adult stomatogastric ganglion (STG) neurons as a function of time in primary cell culture. When first plated in culture, these neurons had few active properties. After 1 d in culture they produced small action potentials that rapidly inactivated during maintained depolarization. After 2 d in culture they fired large action potentials tonically when depolarized, and their properties resembled very closely the properties of STG neurons pharmacologically isolated in the ganglion. After 3-4 d in culture, however, their electrical properties changed and they fired in bursts when depolarized. We characterized the currents expressed by these neurons in culture. They included two TTX-sensitive sodium currents, a calcium current, a delayed-rectifier-like current, a calcium-dependent potassium current, and two A-type currents. The changes in firing properties with time in culture were accompanied by an increase in inward and decrease in outward current densities. A single-compartment conductance-based model of an STG neuron was constructed by fitting the currents measured in the biological neurons. When the current densities in the model neuron were matched to those measured for the biological neurons in each activity state, the model neuron closely reproduced each state, indicating that the changes in current densities are sufficient to account for the changes in intrinsic properties. These data indicate that STG neurons isolated in culture change their intrinsic electrical properties by selectively adjusting the magnitudes of their ionic conductances.

  1. Muscarinic modulation of sodium current by activation of protein kinase C in rat hippocampal neurons.

    Science.gov (United States)

    Cantrell, A R; Ma, J Y; Scheuer, T; Catterall, W A

    1996-05-01

    Phosphorylation of brain Na+ channels by protein kinase C (PKC) decreases peak Na+ current and slows macroscopic inactivation, but receptor-activated modulation of Na+ currents via the PKC pathway has not been demonstrated. We have examined modulation of Na+ channels by activation of muscarinic receptors in acutely-isolated hippocampal neurons using whole-cell voltage-clamp recording. Application of the muscarinic agonist carbachol reduced peak Na+ current and slowed macroscopic inactivation at all potentials, without changing the voltage-dependent properties of the channel. These effects were mediated by PKC, since they were eliminated when the specific PKC inhibitor (PKCI19-36) was included in the pipette solution and mimicked by the extracellular application of the PKC activator, OAG. Thus, activation of endogenous muscarinic receptors on hippocampal neurons strongly modulates Na+ channel activity by activation of PKC. Cholinergic input from basal forebrain neurons may have this effect in the hippocampus in vivo.

  2. Writing and Visualization for Teaching Plate Tectonics

    Science.gov (United States)

    Thomas, S. F.

    2004-12-01

    The Theory of Plate Tectonics is probably the most important paradigm for understanding the workings of our planet. As such it is an integral part in any Introductory Geology course. Whereas geology majors usually easily embrace the Theory of Plate Tectonics, the enthusiasm for the coherence and elegance of this theory appears to be much more subdued among the majority of non-science majors. While visual and electronic media certainly support the teaching of the theory, pretty pictures and animations are not sufficient for many non-science majors to grasp the concepts of interacting lithospheric plates. It is well known that students do better in learning scientific concepts if they create their own understanding through research and inquiry-based learning, by working in the field, manipulating real earth-science data, and through writing. Writing assignments give instructors the opportunity to assess their students' learning and to clarify misconceptions yet they also have to be willing to teach students how to craft a science paper. Most electronic media and textbook-added CD-ROMs are not useful for making the structure of a science paper transparent. I found many of the necessary ingredients for effectively teaching plate tectonics in the interactive CD-ROM, "Our Dynamic Planet", developed by Wm. Prothero together with G. Kelly (University of California at Santa Barbara). It allows students to select and manipulate real earth-science data of plate-tectonically active regions, and provides an electronic interface that lets students create graphical representations of their collected data. A downloadable Teacher's Manual provides suggestions on teaching students to write a scientific argument, rooted in sound pedagogy. Originally designed for a large oceanography class, the material was modified for use in a small introductory geology class for non-science majors. Various assignments were given to instruct students in writing a scientific argument based on their

  3. Plate tectonics, damage and inheritance.

    Science.gov (United States)

    Bercovici, David; Ricard, Yanick

    2014-04-24

    The initiation of plate tectonics on Earth is a critical event in our planet's history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately 3 billion years ago) suggests that plates and plate boundaries became widespread over a period of 1 billion years. The reason for this time lag is unknown but fundamental to understanding the origin of plate tectonics. Here we suggest that when sufficient lithospheric damage (which promotes shear localization and long-lived weak zones) combines with transient mantle flow and migrating proto-subduction, it leads to the accumulation of weak plate boundaries and eventually to fully formed tectonic plates driven by subduction alone. We simulate this process using a grain evolution and damage mechanism with a composite rheology (which is compatible with field and laboratory observations of polycrystalline rocks), coupled to an idealized model of pressure-driven lithospheric flow in which a low-pressure zone is equivalent to the suction of convective downwellings. In the simplest case, for Earth-like conditions, a few successive rotations of the driving pressure field yield relic damaged weak zones that are inherited by the lithospheric flow to form a nearly perfect plate, with passive spreading and strike-slip margins that persist and localize further, even though flow is driven only by subduction. But for hotter surface conditions, such as those on Venus, accumulation and inheritance of damage is negligible; hence only subduction zones survive and plate tectonics does not spread, which corresponds to observations. After plates have developed, continued changes in driving forces, combined with inherited damage and weak zones, promote increased tectonic complexity, such as oblique subduction, strike-slip boundaries that are subparallel to plate motion, and spalling of minor plates.

  4. Tectonics: The meaning of form

    DEFF Research Database (Denmark)

    Christiansen, Karl; Brandt, Per Aage

    Tectonics – The meaning of form deals with one of the core topics of architecture: the relationship between form and content. In the world of architecture, form is not only made from brick, glass and wood. Form means something. When a material is processed with sufficient technical skill and insi...... perspectives. You can read the chapters in any order you like – from the beginning, end or the middle. There is no correct order. The project is methodologically inductive: the more essays you read, the broader your knowledge of tectonics get....

  5. Current Limitations and Recommendations to Improve Testing for the Environmental Assessment of Endocrine Active Substances

    DEFF Research Database (Denmark)

    Coady, Katherine K; Biever, Ronald C; Denslow, Nancy D

    2016-01-01

    evaluate whether a chemical possesses endocrine activity and whether this activity can result in adverse outcomes either to humans or the environment. Current test systems include in silico, in vitro and in vivo techniques focused on detecting potential endocrine activity, and in vivo tests that collect...... apical data to detect possible adverse effects. These test systems are currently designed to robustly assess endocrine activity and/or adverse effects in the estrogen, androgen, and thyroid hormone signaling pathways; however, there are some limitations of current test systems for evaluating endocrine...... methods currently do not exist, and addressing key endocrine pathways of possible concern in addition to those associated with estrogen, androgen and thyroid signaling. This article is protected by copyright. All rights reserved....

  6. 75 FR 4612 - Agency Information Collection Activities: Notice of Request for Extension of Currently Approved...

    Science.gov (United States)

    2010-01-28

    ... construction time and traffic congestion; C. The development of engineering design criteria for innovative... Federal Highway Administration Agency Information Collection Activities: Notice of Request for Extension of Currently Approved Information Collection AGENCY: Federal Highway Administration (FHWA),...

  7. [Resource activation in clinical psychology and psychotherapy: review of theoretical issues and current research].

    Science.gov (United States)

    Groß, L J; Stemmler, M; de Zwaan, M

    2012-08-01

    This review summarises theoretical issues and current research on working with clients' resources and strengths in clinical psychology and psychotherapy. Resource activation is considered as an important common factor in psychotherapy. In general, resource activation means an explicit focus on resources, strengths and potentials of the clients. After defining the term resources, considerations with regard to therapeutic attitude, principles of resource activation, approaches to resource diagnostics and different research strategies are presented. Current research focuses especially on the relation between resource activation and process variables in out-patient treatment.

  8. Extending Whole-earth Tectonics To The Terrestrial Planets

    Science.gov (United States)

    Baker, V. R.; Maruyama, S.; Dohm, J. M.

    Based on the need to explain a great many geological and geophysical anomalies on Mars, and stimulated by the new results from the Mars Global Surveyor Mission, we propose a conceptual model of whole-EARTH (Episodic Annular Revolving Thermal Hydrologic) tectonics for the long-term evolution of terrestrial planets. The theory emphasizes (1) the importance of water in planetary evolution, and (2) the physi- cal transitions in modes of mantle convection in relation to planetary heat produc- tion. Depending on their first-order geophysical parameters and following accretion and differentiation from volatile-rich planetessimals, terrestrial planets should evolve through various stages of mantle convection, including magma ocean, plate tectonic, and stagnant lid processes. If a water ocean is able to condense from the planet's early steam atmosphere, an early regime of plate tectonics will follow the initial magma ocean. This definitely happened on earth, probably on Mars, and possibly on Venus. The Mars history led to transfer of large amounts of water to the mantle during the pe- riod of heavy bombardment. Termination of plate tectonics on Mars during the heavy bombardment period led to initiation of superplumes at Tharsis and Elysium, where long-persistent volcanism and water outbursts dominated much of later Martian his- tory. For Venus, warming of the early sun made the surface ocean unstable, eliminating its early plate-tectonic regime. Although Venus now experiences stagnant-lid convec- tion with episodic mantle overturns, the water subducted to its lower mantle during the ancient plate-tectonic regime manifests itself in the initation of volatile-rich plumes that dominate its current tectonic regime.

  9. Genetic activation of BK currents in vivo generates bidirectional effects on neuronal excitability.

    Science.gov (United States)

    Montgomery, Jenna R; Meredith, Andrea L

    2012-11-13

    Large-conductance calcium-activated potassium channels (BK) are potent negative regulators of excitability in neurons and muscle, and increasing BK current is a novel therapeutic strategy for neuro- and cardioprotection, disorders of smooth muscle hyperactivity, and several psychiatric diseases. However, in some neurons, enhanced BK current is linked with seizures and paradoxical increases in excitability, potentially complicating the clinical use of agonists. The mechanisms that switch BK influence from inhibitory to excitatory are not well defined. Here we investigate this dichotomy using a gain-of-function subunit (BK(R207Q)) to enhance BK currents. Heterologous expression of BK(R207Q) generated currents that activated at physiologically relevant voltages in lower intracellular Ca(2+), activated faster, and deactivated slower than wild-type currents. We then used BK(R207Q) expression to broadly augment endogenous BK currents in vivo, generating a transgenic mouse from a circadian clock-controlled Period1 gene fragment (Tg-BK(R207Q)). The specific impact on excitability was assessed in neurons of the suprachiasmatic nucleus (SCN) in the hypothalamus, a cell type where BK currents regulate spontaneous firing under distinct day and night conditions that are defined by different complements of ionic currents. In the SCN, Tg-BK(R207Q) expression converted the endogenous BK current to fast-activating, while maintaining similar current-voltage properties between day and night. Alteration of BK currents in Tg-BK(R207Q) SCN neurons increased firing at night but decreased firing during the day, demonstrating that BK currents generate bidirectional effects on neuronal firing under distinct conditions.

  10. Active-Only Current Controlled Summing/Difference Amplifiers Using CCCIIs

    Directory of Open Access Journals (Sweden)

    Sudhanshu Maheshwari

    2003-01-01

    Full Text Available Novel active-only summing/difference amplifiers employing only current controlled conveyors (CCCIIs are presented. The circuits possess high input impedance, current controllable gain, good linearity and dynamic range, low THD and are suited for IC implementation. SPICE simulation results are included to verify the circuits.

  11. Effect of Calcium-Activated Chloride Current Blockade on the Delayed Afterdepolarizations. Simulation Study

    Science.gov (United States)

    2007-11-02

    dog and rabbit ventricular cells [4, 6]. The ionic nature of Iti is still subject to debate. Several authors propose two ionic currents to contribute to...activated Cl currents in the heart: a computer model. Computers in Cardiology 1999; 26: 109-112. Julio Gomis-Tena Dolz U.P.V. Departamento de Ingeniería

  12. Active Damping of LLCL-Filter Resonance Based on LC-Trap Voltage or Current Feedback

    DEFF Research Database (Denmark)

    Huang, Min; Wang, Xiongfei; Loh, Poh Chiang;

    2016-01-01

    . Active damping is presently more efficient, and can easily be realized by feeding back a state variable. For the LCL-filter, the variable is usually its middle capacitor current. However, with computational delays considered, a simple proportional damper cannot be used with the capacitor current. Instead...

  13. Structural and stratigraphic controls on the origin and tectonic history of a subducted continental margin, Oman

    Science.gov (United States)

    Warren, C. J.; Miller, J. McL.

    2007-03-01

    Eclogites and blueschists exposed in Saih Hatat, Oman, record the subduction and exhumation of continental crustal material beneath the Cretaceous Semail Ophiolite during ophiolite obduction. The eclogite-bearing lower plate, originally part of Oman's distal continental margin, is exposed in two tectonic windows through the less metamorphosed upper plate by a previously mapped low angle, high strain, décollement structure. A major tectonic break, currently poorly exposed, records the juxtaposition of the highest pressure eclogites and garnet blueschists against lower pressure epidote-blueschists. The subsequent exhumation of the entire lower plate to mid crustal levels is marked by a pervasive shearing event associated with a regional greenschist facies overprint. The décollement truncates structures and the metamorphic field gradient in the lower plate, but does not significantly truncate structures or stratigraphy in the upper plate. It is not responsible for the exhumation of the high pressure rocks to mid-crustal levels. Most of the displacement across this structure was accommodated during continuing convergence after the subduction system had ceased to be active, and post ophiolite emplacement onto the platform carbonate sequences. A revised tectonic model is presented which accounts for the structural, geochronological and metamorphic observations.

  14. A case control study of premorbid and currently reported physical activity levels in chronic fatigue syndrome

    Directory of Open Access Journals (Sweden)

    Buchwald Dedra

    2006-11-01

    Full Text Available Abstract Background Patients with chronic fatigue syndrome typically report high levels of physical activity before becoming ill. Few studies have examined premorbid and current activity levels in chronically fatigued patients. Methods In a case-control study, 33 patients with chronic, unexplained, disabling fatigue attending a university-based clinic specializing in fatigue were compared to 33 healthy, age- and sex-matched controls. Patients rated their activity levels before their illness and currently, using scales designed for this purpose. Controls reported their level of activity of 2 years previously and currently. Chi-square analyses, Student's t tests, and Wilcoxon signed rank tests were used in pair matched analyses. Results Compared to healthy controls, patients with chronic, unexplained fatigue rated themselves as more active before their illness (p ≤ 0.001 and less active currently (p ≤ 0.001. The patients also reported they currently stood or walked less than the controls (median [inter-quartile range] = 4 2345 versus 9 [7.5–12] hours, p ≤ 0.001, and spent more time reclining (median [inter-quartile range] = 12 10111213141516 versus 8 [8–9.5] hours, p ≤ 0.001. These differences remained significant for the subset of patients who met strict criteria for chronic fatigue syndrome or fibromyalgia. Conclusion Patients with chronic, unexplained, disabling fatigue reported being more active before becoming ill than healthy controls. This finding could be explained by greater premorbid activity levels that could predispose to illness, or by an overestimation of previous activity. Either possibility could influence patients' perceptions of their current activity levels and their judgments of recovery. Perceived activity should be addressed as part of management of the illness.

  15. Geomorphology and Neogene tectonic evolution of the Palomares continental margin (Western Mediterranean)

    Science.gov (United States)

    Gómez de la Peña, Laura; Gràcia, Eulàlia; Muñoz, Araceli; Acosta, Juan; Gómez-Ballesteros, María; R. Ranero, César; Uchupi, Elazar

    2016-10-01

    The Palomares continental margin is located in the southeastern part of Spain. The margin main structure was formed during Miocene times, and it is currently part of the wide deformation zone characterizing the region between the Iberian and African plates, where no well-defined plate boundary occurs. The convergence between these two plates is here accommodated by several structures, including the left lateral strike-slip Palomares Fault. The region is characterized by sparse, low to moderate magnitude (Mw tectonic history of the margin we analyze new high-resolution multibeam bathymetry data and re-processed three multichannel seismic reflection profiles crossing the main structures. The analysis of seafloor morphology and associated subsurface structure provides new insights of the active tectonic features of the area. In contrast to other segments of the southeastern Iberian margin, the Palomares margin contains numerous large and comparatively closely spaced canyons with heads that reach near the coast. The margin relief is also characterized by the presence of three prominent igneous submarine ridges that include the Aguilas, Abubacer and Maimonides highs. Erosive processes evidenced by a number of scars, slope failures, gullies and canyon incisions shape the present-day relief of the Palomares margin. Seismic images reveal the deep structure distinguishing between Miocene structures related to the formation of the margin and currently active features, some of which may reactivate inherited structures. The structure of the margin started with an extensional phase accompanied by volcanic accretion during the Serravallian, followed by a compressional pulse that started during the Latemost Tortonian. Nowadays, tectonic activity offshore is subdued and limited to few, minor faults, in comparison with the activity recorded onshore. The deep Algero-Balearic Basin is affected by surficial processes, associated to halokinesis of Messinian evaporites.

  16. Sensory deprivation regulates the development of the hyperpolarization-activated current in auditory brainstem neurons.

    Science.gov (United States)

    Hassfurth, Benjamin; Magnusson, Anna K; Grothe, Benedikt; Koch, Ursula

    2009-10-01

    Hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels are highly expressed in the superior olivary complex, the primary locus for binaural information processing. This hyperpolarization-activated current (I(h)) regulates the excitability of neurons and enhances the temporally precise analysis of the binaural acoustic cues. By using the whole-cell patch-clamp technique, we examined the properties of I(h) current in neurons of the lateral superior olive (LSO) and the medial nucleus of the trapezoid body (MNTB) before and after hearing onset. Moreover, we tested the hypothesis that I(h) currents are actively regulated by sensory input activity by performing bilateral and unilateral cochlear ablations before hearing onset, resulting in a chronic auditory deprivation. The results show that after hearing onset, I(h) currents are rapidly upregulated in LSO neurons, but change only marginally in neurons of the MNTB. We also found a striking difference in maximal current density, voltage dependence and activation time constant between the LSO and the MNTB in mature-like animals. Following bilateral cochlear ablations before hearing onset, the I(h) currents were scaled up in the LSO and scaled down in the MNTB. Consequently, in the LSO this resulted in a depolarized resting membrane potential and a lower input resistance of these neurons. This type of activity-dependent homeostatic change could thus result in an augmented response to the remaining inputs.

  17. Cell cycle-dependent activity of the volume- and Ca2+-activated anion currents in Ehrlich lettre ascites cells

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjaer; Bergdahl, Andreas; Christophersen, Palle

    2007-01-01

    Recent evidence implicates the volume-regulated anion current (VRAC) and other anion currents in control or modulation of cell cycle progression; however, the precise involvement of anion channels in this process is unclear. Here, Cl- currents in Ehrlich Lettre Ascites (ELA) cells were monitored...... during cell cycle progression, under three conditions: (i) after osmotic swelling (i.e., VRAC), (ii) after an increase in the free intracellular Ca2+ concentration (i.e., the Ca2+-activated Cl- current, CaCC), and (iii) under steady-state isotonic conditions. The maximal swelling-activated VRAC current......+ in the pipette), was unaltered from G0 to G1, but decreased in early S phase. A novel high-affinity anion channel inhibitor, the acidic di-aryl-urea NS3728, which inhibited both VRAC and CaCC, attenuated ELA cell growth, suggesting a possible mechanistic link between cell cycle progression and cell cycle...

  18. Negative-shift activation, current reduction and resurgent currents induced by β-toxins from Centruroides scorpions in sodium channels.

    Science.gov (United States)

    Schiavon, Emanuele; Pedraza-Escalona, Martha; Gurrola, Georgina B; Olamendi-Portugal, Timoteo; Corzo, Gerardo; Wanke, Enzo; Possani, Lourival D

    2012-02-01

    The β-toxins purified from the New World scorpion venoms of the Centruroides species affect several voltage-gated sodium channels (VGSCs) and thus are essential tools not only for the discrimination of different channel sub-types but also for studying the structure-function relationship between channels and toxins. This communication reports the results obtained with four different peptides purified from three species of Centruroides scorpions and assayed on seven distinct isoforms of VGSC (Na(v)1.1-Na(v)1.7) by specific functional analysis conducted through single cell electrophysiology. The toxins studied were CssII from Centruroides suffusus suffusus, Cll1 and Cll2 from Centruroides limpidus limpidus and a novel toxin from Centruroides noxius, which was characterized for the first time here. It has 67 amino acid residues and four disulfide bridges with a molecular mass of 7626 Da. Three different functional features were identified: current reduction of macroscopic conductance, left shift of the voltage-dependent activation and induction of resurgent currents at negative voltages following brief, strong depolarizations. The isoforms which revealed to be more affected resulted to be Na(v)1.6 > 1.1 > 1.2 and, for the first time, a β-toxin is here shown to induce resurgent current also in isoforms different from Na(v)1.6. Additionally, these results were analyzed with molecular modelling. In conclusion, although the four toxins have a high degree of identity, they display tri-modal function, each of which shows selectivity among the different sub-types of Na+ -channels. Thus, they are invaluable as tools for structure-function studies of β-toxins and offer a basis for the design of novel ion channel-specific drugs.

  19. THE EVOLUTION OF THE ELECTRIC CURRENT DURING THE FORMATION AND ERUPTION OF ACTIVE-REGION FILAMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jincheng; Yan, Xiaoli; Qu, Zhongquan; Xue, Zhike; Xiang, Yongyuan; Li, Hao, E-mail: egnever@ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China)

    2016-02-01

    We present a comprehensive study of the electric current related to the formation and eruption of active region filaments in NOAA AR 11884. The vertical current on the solar surface was investigated by using vector magnetograms (VMs) observed by HMI on board the Solar Dynamics Observatory. To obtain the electric current along the filament's axis, we reconstructed the magnetic fields above the photosphere by using nonlinear force-free field extrapolation based on photospheric VMs. Spatio-temporal evolutions of the vertical current on the photospheric surface and the horizontal current along the filament's axis were studied during the long-term evolution and eruption-related period, respectively. The results show that the vertical currents of the entire active region behaved with a decreasing trend and the magnetic fields also kept decreasing during the long-term evolution. For the eruption-related evolution, the mean transverse field strengths decreased before two eruptions and increased sharply after two eruptions in the vicinity of the polarity inversion lines underneath the filament. The related vertical current showed different behaviors in two of the eruptions. On the other hand, a very interesting feature was found: opposite horizontal currents with respect to the current of the filament's axis appeared and increased under the filament before the eruptions and disappeared after the eruptions. We suggest that these opposite currents were carried by the new flux emerging from the photosphere bottom and might be the trigger mechanism for these filament eruptions.

  20. The Evolution of the Electric Current during the Formation and Eruption of Active-region Filaments

    Science.gov (United States)

    Wang, Jincheng; Yan, Xiaoli; Qu, Zhongquan; Xue, Zhike; Xiang, Yongyuan; Li, Hao

    2016-02-01

    We present a comprehensive study of the electric current related to the formation and eruption of active region filaments in NOAA AR 11884. The vertical current on the solar surface was investigated by using vector magnetograms (VMs) observed by HMI on board the Solar Dynamics Observatory. To obtain the electric current along the filament's axis, we reconstructed the magnetic fields above the photosphere by using nonlinear force-free field extrapolation based on photospheric VMs. Spatio-temporal evolutions of the vertical current on the photospheric surface and the horizontal current along the filament's axis were studied during the long-term evolution and eruption-related period, respectively. The results show that the vertical currents of the entire active region behaved with a decreasing trend and the magnetic fields also kept decreasing during the long-term evolution. For the eruption-related evolution, the mean transverse field strengths decreased before two eruptions and increased sharply after two eruptions in the vicinity of the polarity inversion lines underneath the filament. The related vertical current showed different behaviors in two of the eruptions. On the other hand, a very interesting feature was found: opposite horizontal currents with respect to the current of the filament's axis appeared and increased under the filament before the eruptions and disappeared after the eruptions. We suggest that these opposite currents were carried by the new flux emerging from the photosphere bottom and might be the trigger mechanism for these filament eruptions.

  1. Inhibition of volume-activated chloride currents in endothelial cells by chromones.

    Science.gov (United States)

    Heinke, S.; Szücs, G.; Norris, A.; Droogmans, G.; Nilius, B.

    1995-01-01

    1. We have studied the effects of the reported chloride channel blocker, sodium cromoglycate, on volume-activated Cl- currents in endothelial cells from bovine pulmonary artery by means of the whole-cell patch clamp technique. Cl- currents were activated by challenging the cells with a hypotonic extracellular solution of 60% of the normal osmolarity. 2. Half maximal activation of the current at +95 mV occurred after exposure of the cells for 148 +/- 10 s (n = 6) to hypotonic solution (HTS). At the same membrane potential but in the presence of 100 microM sodium cromoglycate (disodium-1,3-bis (2'-carboxylate-chromone-5'-yloxy)-2-hydroxy-propane) activation was delayed (253 +/- 25 s, n = 6) and the maximal current amplitude was reduced to 63 +/- 7% of the control (n = 13). 3. In comparison, an equimolar concentration of NPPB (5-nitro-2(3-phenyl) propylamino-benzoic acid), another Cl- channel blocker, completely blocked the volume-activated current in less than 20 s. 4. Sodium cromoglycate, applied at the time when the HTS-induced current was completely activated, dose-dependently inhibited this current with a concentration for half maximal inhibition of 310 +/- 70 microM. Data for nedocromil sodium were not significantly different from those for sodium cromoglycate. 5. Sodium cromoglycate, loaded into the endothelial cells via the patch pipette in ruptured patches, resulted in a decline of the HTS activated current with a time course that was compatible with diffusion of the compound from the pipette into the cell.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8564197

  2. Global Tectonics of Enceladus: Numerical Model

    Science.gov (United States)

    Czechowski, Leszek

    2016-10-01

    Introduction: Enceladus, a satellite of Saturn, is the smallest celestial body in the Solar System where volcanic and tectonic activities are observed. Every second, the mass of 200 kg is ejected into space from the South Polar Terrain (SPT) - [1]. The loss of matter from the body's interior should lead to global compression of the crust. Typical effects of compression are: thrust faults, folding and subduction. However, such forms are not dominant on Enceladus. We propose here special tectonic process that could explain this paradox. Our hypotheses states that the mass loss from SPT is the main driving mechanism of the following tectonic processes: subsidence of SPT, flow in the mantle and motion of adjacent tectonic plates. The hypotheses is presented in [2], [3] and[4].We suggest that the loss of the volatiles results in a void, an instability, and motion of solid matter to fill the void. The motion is presented at the Fig.1 and includes:Subsidence of the 'lithosphere' of SPT.Flow of the matter in the mantle.Motion of plates adjacent to SPT towards the active regionMethods and results: The numerical model of processes presented is developed. It is based on the equations of continuous media..If emerging void is being filled by the subsidence of SPT only, then the velocity of subsidence is 0.05 mmyr-1. However, numerical calculations indicate that all three types of motion are usually important. The role of a given motion depends on the viscosity distribution. Generally, for most of the models the subsidence is 0.02 mmyr-1, but mantle flow and plates' motion also play a role in filling the void. The preliminary results of the numerical model indicate also that the velocity of adjacent plates could be 0.02 mmyr-1 for the Newtonian rheology.Note that in our model the reduction of the crust area is not a result of compression but it is a result of the plate sinking. Therefore the compressional surface features do not have to be dominant. The SPT does not have to be

  3. Comment on "Intermittent plate tectonics?".

    Science.gov (United States)

    Korenaga, Jun

    2008-06-06

    Silver and Behn (Reports, 4 January 2008, p. 85) proposed that intermittent plate tectonics may resolve a long-standing paradox in Earth's thermal evolution. However, their analysis misses one important term, which subsequently brings their main conclusion into question. In addition, the Phanerozoic eustasy record indicates that the claimed effect of intermittency is probably weak.

  4. Tectonic evolution of terrestrial planets

    Science.gov (United States)

    Head, J. W.; Solomon, S. C.

    1981-01-01

    The tectonic style of each terrestrial planet, referring to the thickness and division of its lithosphere, can be inferred from surface features and compared to models of planetary thermal history. Factors governing planetary tectonic evolution are planet diameter, chemistry, and external and internal heat sources, all of which determine how a planet generates and rids itself of heat. The earth is distinguished by its distinct, mobile plates, which are recycled into the mantle and show large-scale lateral movements, whereas the moon, Mars, and Mercury are single spherical shells, showing no evidence of destruction and renewal of the lithospheric plates over the latter 80% of their history. Their smaller volume to surface area results in a more rapid cooling, formation, and thickening of the lithosphere. Vertical tectonics, due to lithospheric loading, is controlled by the local thickness and rheology of the lithosphere. Further studies of Venus, which displays both the craterlike surface features of the one-plate planets, and the rifts and plateaus of earth, may indicate which factors are most important in controlling the tectonic evolution of terrestrial planets.

  5. The steady-state performance of a controlled current active filter

    Energy Technology Data Exchange (ETDEWEB)

    Duke, R.M. (Univ. of Canterbury, Christchurch (New Zealand). Dept. of Electrical and Electronic Engineering); Round, S.D. (Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Electrical Engineering)

    1993-04-01

    An active filter that uses a high-frequency D-class asynchronous switching inverter for power system current distortion compensation is described. The distortion compensation technique involves deriving a signal corresponding to the distortion component of load current, and inverting and amplifying this signal for addition back to the supply current to cancel the load current distortion. A synthetic sinusoid is used to determine the distortion component in the time domain. Extensive computed and experimental results, illustrating the system's steady-state performance and ability to reduce the current harmonic distortion components, are presented. An intelligent controller is proposed to maintain the active filter's performance at the optimal operating point under varying load conditions.

  6. Low-level electrical currents and brain indicators of behavioral activation

    Directory of Open Access Journals (Sweden)

    F. Lolas

    1977-12-01

    Full Text Available Distinguishing between slow brain potential correlates of arousal and activation on the basis of their functional role and temporal involvement during a reaction-time task, data are presented which suggest that weak electrical polarizing currents applied to the head in human subjects modify predominantly activation indicators rather than arousal ones.

  7. The polyphased tectonic evolution of the Anegada Passage in the northern Lesser Antilles subduction zone

    Science.gov (United States)

    Laurencin, M.; Marcaillou, B.; Graindorge, D.; Klingelhoefer, F.; Lallemand, S.; Laigle, M.; Lebrun, J.-F.

    2017-05-01

    The influence of the highly oblique plate convergence at the northern Lesser Antilles onto the margin strain partitioning and deformation pattern, although frequently invoked, has never been clearly imaged. The Anegada Passage is a set of basins and deep valleys, regularly related to the southern boundary of the Puerto Rico-Virgin Islands (PRVI) microplate. Despite the publications of various tectonic models mostly based on bathymetric data, the tectonic origin and deformation of this Passage remains unconstrained in the absence of deep structure imaging. During cruises Antithesis 1 and 3 (2013-2016), we recorded the first deep multichannel seismic images and new multibeam data in the northern Lesser Antilles margin segment in order to shed a new light on the structure and tectonic pattern of the Anegada Passage. We image the northeastern extent of the Anegada Passage, from the Sombrero Basin to the Lesser Antilles margin front. Our results reveal that this northeastern segment is an EW trending left-stepping en échelon strike-slip system that consists of the Sombrero and Malliwana pull-apart basins, the Malliwana and Anguilla left-lateral faults, and the NE-SW compressional restraining bend at the Malliwana Hill. Reviewing the structure of the Anegada Passage, from the south of Puerto Rico to the Lesser Antilles margin front, reveals a polyphased tectonic history. The Anegada Passage is formed by a NW-SE extension, possibly related to the rotation or escape of PRVI block due to collision of the Bahamas Bank. Currently, it is deformed by an active WNW-ESE strike-slip deformation associated to the shear component of the strain partitioning resulting from the subduction obliquity.

  8. Tectonics control over instability of volcanic edifices in transtensional tectonic regimes

    Science.gov (United States)

    Norini, G.; Capra, L.; Lagmay, A. M. F.; Manea, M.; Groppelli, G.

    2009-04-01

    We present the results of analogue modeling designed to investigate the interactions between volcanic edifices and transtensional basement faulting. Three sets of experiments were run to account for three examples of stratovolcanoes in active transtensive tectonics regimes, the Nevado de Toluca and Jocotitlan volcanoes in Mexico, and the Mayon volcano in the Philippines. All these volcanoes show different behavior and relationship among volcanism, instability of the volcanic edifice, and basement tectonics. Field geological and structural data gave the necessary constrains to the models. The modeling apparatus consisted of a sand cone on a sheared basal layer. Injections of vegetable oil were used to model the rising of magma inside the deformed analogue cones. Set 1: In the case of a volcano directly on top of a basal transtensive shear producing a narrow graben, as observed on the Nevado de Toluca volcano, the analogue models reveal a strong control of the basement faulting on the magma migration path and the volcano instability. Small lateral collapses are directed parallel to the basal shear and affect a limited sector of the cone. Set 2: If the graben generated by transtensive tectonics is bigger in respect to the volcanic edifice and the volcano sits on one boundary fault, as in the case of Mayon volcano, the combined normal and transcurrent movements of the analogue basement fault generate a sigmoidal structure in the sand cone, inducing major sector collapses directed at approx 45° relative to the basement shear toward the downthrown block. Set 3: For volcanoes located near major transtensive faults, as the Jocotitlan volcano, analogue modelling shows an important control of the regional tectonics on the geometry of the fractures and migration paths of magma inside the cone. These structures render unstable the flanks of the volcano and promote sector collapses perpendicular to the basement shear and directed toward the graben formed by the transtensive

  9. Hyperpolarization-Activated Current, , in Mathematical Models of Rabbit Sinoatrial Node Pacemaker Cells

    Directory of Open Access Journals (Sweden)

    Arie O. Verkerk

    2013-01-01

    Full Text Available A typical feature of sinoatrial (SA node pacemaker cells is the presence of an ionic current that activates upon hyperpolarization. The role of this hyperpolarization-activated current, , which is also known as the “funny current” or “pacemaker current,” in the spontaneous pacemaker activity of SA nodal cells remains a matter of intense debate. Whereas some conclude that plays a fundamental role in the generation of pacemaker activity and its rate control, others conclude that the role of is limited to a modest contribution to rate control. The ongoing debate is often accompanied with arguments from computer simulations, either to support one's personal view or to invalidate that of the antagonist. In the present paper, we review the various mathematical descriptions of that have been used in computer simulations and compare their strikingly different characteristics with our experimental data. We identify caveats and propose a novel model for based on our experimental data.

  10. Early and current physical activity: relationship with intima-media thickness and metabolic variables in adulthood

    Directory of Open Access Journals (Sweden)

    Manoel C. S. Lima

    2014-10-01

    Full Text Available Background: It is unclear whether early physical activity has a greater influence on intima-media thickness and metabolic variables than current physical activity. Objective: To analyze the relationship between current and early physical activity, metabolic variables, and intima-media thickness measures in adults. Method: The sample was composed of 55 healthy subjects of both sexes (33 men and 22 women. Total body fat and trunk fat were estimated by dual-energy X-ray absorptiometry. Carotid and femoral intima-media thickness were measured using a Doppler ultrasound device. A 12-hour fasting blood sample collection was taken (fasting glucose and lipid profile. Early physical activity was assessed through face-to-face interview, and the current physical activity was assessed by pedometer (Digi-Walker Yamax, SW200, which was used for a period of seven days. Results: Current physical activity was negatively related to total cholesterol (rho=-0.31, while early physical activity was negatively related to triglycerides (rho=-0.42, total cholesterol (rho=-0.28, very low density lipoprotein (rho=-0.44, and carotid intima-media thickness (rho=-0.50. In the multivariate model, subjects engaged in sports activities during early life had lower values of very low density lipoprotein (b=-8.74 [b=-16.1; -1.47] and carotid intima-media thickness (b=-0.17 [95%CI: -0.28; -0.05]. Conclusion: Early 95%CI physical activity has a significant influence on carotid intima-media thickness, regardless of the current physical activity.

  11. Early and current physical activity: relationship with intima-media thickness and metabolic variables in adulthood.

    Science.gov (United States)

    Lima, Manoel C S; Barbosa, Maurício F; Diniz, Tiego A; Codogno, Jamile S; Freitas Júnior, Ismael F; Fernandes, Rômulo A

    2014-01-01

    It is unclear whether early physical activity has a greater influence on intima-media thickness and metabolic variables than current physical activity. To analyze the relationship between current and early physical activity, metabolic variables, and intima-media thickness measures in adults. The sample was composed of 55 healthy subjects of both sexes (33 men and 22 women). Total body fat and trunk fat were estimated by dual-energy X-ray absorptiometry. Carotid and femoral intima-media thickness were measured using a Doppler ultrasound device. A 12-hour fasting blood sample collection was taken (fasting glucose and lipid profile). Early physical activity was assessed through face-to-face interview, and the current physical activity was assessed by pedometer (Digi-Walker Yamax, SW200), which was used for a period of seven days. Current physical activity was negatively related to total cholesterol (rho=-0.31), while early physical activity was negatively related to triglycerides (rho=-0.42), total cholesterol (rho=-0.28), very low density lipoprotein (rho=-0.44), and carotid intima-media thickness (rho=-0.50). In the multivariate model, subjects engaged in sports activities during early life had lower values of very low density lipoprotein (b=-8.74 [b95%CI=-16.1; -1.47]) and carotid intima-media thickness (b=-0.17 [95%CI: -0.28; -0.05]). Early 95%CI physical activity has a significant influence on carotid intima-media thickness, regardless of the current physical activity.

  12. Investigating the landscape of Arroyo Seco—Decoding the past—A teaching guide to climate-controlled landscape evolution in a tectonically active region

    Science.gov (United States)

    Taylor, Emily M.; Sweetkind, Donald S.; Havens, Jeremy C.

    2017-05-19

    IntroductionArroyo Seco is a river that flows eastward out of the Santa Lucia Range in Monterey County, California. The Santa Lucia Range is considered part of the central California Coast Range. Arroyo Seco flows out of the Santa Lucia Range into the Salinas River valley, near the town of Greenfield, where it joins the Salinas River. The Salinas River flows north into Monterey Bay about 40 miles from where it merges with Arroyo Seco. In the mountain range, Arroyo Seco has cut or eroded a broad and deep valley. This valley preserves a geologic story in the landscape that is influenced by both fault-controlled mountain building (tectonics) and sea level fluctuations (regional climate).Broad flat surfaces called river terraces, once eroded by Arroyo Seco, can be observed along the modern drainage. In the valley, terraces are also preserved like climbing stairs up to 1,800 feet above Arroyo Seco today. These terraces mark where Arroyo Seco once flowed.The terraces were formed by the river because no matter how high they are, the terraces are covered by gravel deposits exactly like those that can be observed in the river today. The Santa Lucia Range, Arroyo Seco, and the Salinas River valley must have looked very different when the highest and oldest terraces were forming. The Santa Lucia Range may have been lower, the Arroyo Seco may have been steeper and wider, and the Salinas River valley may have been much smaller.Arroyo Seco, like all rivers, is always changing. Some-times rivers flow very straight, and sometimes they are curvy. Sometimes rivers are cutting down or eroding the landscape, and sometimes they are not eroding but depositing material. Sometimes rivers are neither eroding nor transporting material. The influences that change the behavior of Arroyo Seco are mountain uplift caused by fault moment and sea level changes driven by regional climate change. When a stream is affected by one or both of these influences, the stream accommodates the change by

  13. Niflumic acid reduces the hyperpolarization-activated current (I(h)) in rod photoreceptor cells.

    Science.gov (United States)

    Satoh, T O; Yamada, M

    2001-08-01

    We examined the effects of niflumic acid (NFA), a chloride channel blocker, on the hyperpolarization-activated current (I(h)) in newt rod photoreceptors. At 100 microM, NFA delayed the activation of I(h) induced by hyperpolarizing voltage pulses to -83 mV from a holding potential of -43 mV, and reduced the steady-state current. However, reduction by NFA was weakened when I(h) was activated by hyperpolarizing steps to -123 mV, suggesting that these effects were voltage-dependent. The suppressive effects of NFA on I(h) were accompanied by a negative shift in activation voltage. NFA also delayed the relaxation of I(h) tail currents, showing that this drug also inhibited deactivation of the current. The reversal potential and the fully activated conductance were not affected. These observations suggest that NFA reduces I(h) by modifying the gating kinetics of the underlying channels. The suppressive actions of NFA remained when intracellular Ca2+ was strongly chelated, and the failure of suppression by NFA in inside-out patches suggests that the agent may act on the I(h) channel from the extracellular side. These results, obtained in rod photoreceptors, are consistent with similar effects of NFA on I(f) in cardiac myocytes, suggesting that both currents share similar pharmacological properties.

  14. Planets and satellites: tectonic twins

    Science.gov (United States)

    Kochemasov, G. G.

    2015-10-01

    There are only three solid planet-satellite pairs in the Solar system: Earth -Moon, Mars -Phobos, Pluto - Charon. For the first two pairs tectonic analogies were shown and explained by moving them in one circumsolar orbit. As it is known from the wave planetology [3, 4, 6], "orbits make structures". For the third pair the same was stated as a prediction based on this fundamental rule. Global tectonic forms of wave origin appear in cosmic bodies because they move in keplerian orbits with periodically changing accelerations. Warping bodies waves have a stationary character and obeying wave harmonics lengths. Starting from the fundamental 2πR-long wave 1 making the ubiquitous tectonic dichotomy (two-face appearance) warping wave lengths descend along harmonics. Very prominent along with the wave 1 are waves 2 responsible for tectonic sectoring superimposed on the wave 1 segments. Practically all bodies have traces of shorter waves making numerous polygons (rings) often confused with impact craters. Earth and the Moon moving in one circumsolar orbit both are distorted by wave 1, wave 2 and wave 4 features aligned along extent tectonic lines [4, 5]. At Earth they are: Pacific Ocean (2πR-structure) and Indian Ocean (πR-structure) from both ends with Malay Archipelago (πR/4-structure) in the middle. At Moon they are: Procellarum Ocean (2πR) and SPA Basin (πR) from ends and Mare Orientale (πR/4) in the middle. A regular disposition is surprising. Both Oceans and Basin occur on opposite hemispheres, lying in the middle both ring structures occur in the boundary between two hemispheres and are of the same relative size. These triads stretch along lines parallel to the equator (Earth) and with the angle about 30 degrees to it (Moon) indicating at a different orientation of the rotation axes in the ancient time [2]. On the whole, one could speak about a "lunar mould" of Earth [5] (Fig. 1-3). Another tectonic twin is the pair Mars -Phobos. Both bodies sharing one

  15. TERRAIN TECTONICS OF THE CENTRAL ASIAN FOLDED BELT

    Directory of Open Access Journals (Sweden)

    M. M. Buslov

    2015-09-01

    Full Text Available The terrain analysis concept envisages primarily a possibility of approximation of fragments / terrains of various geodynamic settings which belong to different plates. The terrain analysis can supplement the theory of plate tectonics in solving problems of geodynamics and tectonics of regions of the crust with complex structures. The Central Asian belt is among such complicated regions. Terrain structures occurred as a result of combined movements in the system of 'frontal' and/or oblique subduction – collision. In studies of geological objects, it is required first of all to prove their (vertical and horizontal autochthony in relations to each other and then proceed to paleogeodynamic, paleotectonic and paleogeographic reconstructions. Obviously, such a complex approach needs data to be obtained by a variety of research methods, including those applied to study geologic structures, stratigraphy, paleontology, paleogeography, lithothlogy, geochemistry, geochronology, paleomagnetism etc. Only by correlating such data collected from inter-disciplinary studies of the regions, it is possible to establish reliable characteristics of the geological settings and avoid mistakes and misinterpretations that may be associated with the 'stratigraphic' approach to solutions of both regional and global problems of geodynamics and tectonics of folded areas. The terrain analysis of the Central Asian folded belt suggests that its tectonic structure combines marginal continental rock complexes that were formed by the evolution of two major oceanic plates. One of them is the plate of the Paleo-Asian Ocean. As the analogue of the current Indo-Atlantic segment of Earth, it is characterised by the presence of continental blocks in the composition of the oceanic crust and the formation of oceanic basins resulting from the breakup of Rodinia and Gondvana. In the course of its evolution, super-continents disintegrated, and the blocks were reunited into the Kazakhstan

  16. FCCP depolarizes plasma membrane potential by activating proton and Na+ currents in bovine aortic endothelial cells.

    Science.gov (United States)

    Park, Kyu-Sang; Jo, Inho; Pak, Kim; Bae, Sung-Won; Rhim, Hyewhon; Suh, Suk-Hyo; Park, Jin; Zhu, Hong; So, Insuk; Kim, Ki Whan

    2002-01-01

    We investigated the effects of carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP), a protonophore and uncoupler of mitochondrial oxidative phosphorylation in mitochondria, on plasma membrane potential and ionic currents in bovine aortic endothelial cells (BAECs). The membrane potential and ionic currents of BAECs were recorded using the patch-clamp technique in current-clamp and voltage-clamp modes, respectively. FCCP activated ionic currents and depolarized the plasma membrane potential in a dose-dependent manner. Neither the removal of extracellular Ca2+ nor pretreatment with BAPTA/AM affected the FCCP-induced currents, implying that the currents are not associated with the FCCP-induced intracellular [Ca2+]i increase. FCCP-induced currents were significantly influenced by the changes in extracellular or intracellular pH; the increased proton gradient produced by lowering the extracellular pH or intracellular alkalinization augmented the changes in membrane potential and ionic currents caused by FCCP. FCCP-induced currents were significantly reduced under extracellular Na+-free conditions. The reversal potentials of FCCP-induced currents under Na+-free conditions were well fitted to the calculated equilibrium potential for protons. Interestingly, FCCP-induced Na+ transport (subtracted currents, I(control)- I(Na+-free) was closely dependent on extracellular pH, whereas FCCP-induced H+transport was not significantly affected by the absence of Na+. These results suggest that the FCCP-induced ionic currents and depolarization, which are strongly dependent on the plasmalemmal proton gradient, are likely to be mediated by both H+ and Na+ currents across the plasma membrane. The relationship between H+ and Na+ transport still needs to be determined.

  17. Adaptive Current Control with PI-Fuzzy Compound Controller for Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Juntao Fei

    2013-01-01

    Full Text Available An adaptive control technology and PI-fuzzy compound control technology are proposed to control an active power filter (APF. AC side current compensation and DC capacitor voltage tracking control strategy are discussed and analyzed. Model reference adaptive controller for the AC side current compensation is derived and established based on Lyapunov stability theory; proportional and integral (PI fuzzy compound controller is designed for the DC side capacitor voltage control. The adaptive current controller based on PI-fuzzy compound system is compared with the conventional PI controller for active power filter. Simulation results demonstrate the feasibility and satisfactory performance of the proposed control strategies. It is shown that the proposed control method has an excellent dynamic performance such as small current tracking error, reduced total harmonic distortion (THD, and strong robustness in the presence of parameters variation and nonlinear load.

  18. Paralleling power MOSFETs in their active region: Extended range of passively forced current sharing

    Science.gov (United States)

    Niedra, Janis M.

    1989-01-01

    A simple passive circuit that improves current balance in parallelled power MOSFETs that are not precisely matched and that are operated in their active region from a common gate drive are exhibited. A nonlinear circuit consisting of diodes and resistors generates the differential gate potential required to correct for unbalance while maintaining low losses over a range of current. Also application of a thin tape wound magnetic core to effect dynamic current balance is reviewed, and a simple theory is presented showing that for operation in the active region the branch currents tend to revert to their normal unbalanced values even if the core is not driven into saturation. Results of several comparative experiments are given.

  19. Three-dimensional ventricular activation imaging by means of equivalent current source modeling and estimation.

    Science.gov (United States)

    Liu, Z; Liu, C; He, B

    2006-01-01

    This paper presents a novel electrocardiographic inverse approach for imaging the 3-D ventricular activation sequence based on the modeling and estimation of the equivalent current density throughout the entire myocardial volume. The spatio-temporal coherence of the ventricular excitation process is utilized to derive the activation time from the estimated time course of the equivalent current density. At each time instant during the period of ventricular activation, the distributed equivalent current density is noninvasively estimated from body surface potential maps (BSPM) using a weighted minimum norm approach with a spatio-temporal regularization strategy based on the singular value decomposition of the BSPMs. The activation time at any given location within the ventricular myocardium is determined as the time point with the maximum local current density estimate. Computer simulation has been performed to evaluate the capability of this approach to image the 3-D ventricular activation sequence initiated from a single pacing site in a physiologically realistic cellular automaton heart model. The simulation results demonstrate that the simulated "true" activation sequence can be accurately reconstructed with an average correlation coefficient of 0.90, relative error of 0.19, and the origin of ventricular excitation can be localized with an average localization error of 5.5 mm for 12 different pacing sites distributed throughout the ventricles.

  20. β-pompilidotoxin modulates spontaneous activity and persistent sodium currents in spinal networks.

    Science.gov (United States)

    Magloire, V; Czarnecki, A; Anwander, H; Streit, J

    2011-01-13

    The origin of rhythm generation in mammalian spinal cord networks is still poorly understood. In a previous study, we showed that spontaneous activity in spinal networks takes its origin in the properties of certain intrinsically spiking interneurons based on the persistent sodium current (INaP). We also showed that depolarization block caused by a fast inactivation of the transient sodium current (INaT) contributes to the generation of oscillatory activity in spinal cord cultures. Recently, a toxin called beta-pompilidotoxin (β-PMTX) that slows the inactivation process of tetrodotoxin (TTX)-sensitive sodium channels has been extracted from the solitary wasp venom. In the present study, we therefore investigated the effect of β-PMTX on rhythm generation and on sodium currents in spinal networks. Using intracellular recordings and multielectrode array (MEA) recordings in dissociated spinal cord cultures from embryonic (E14) rats, we found that β-PMTX reduces the number of population bursts and increases the background asynchronous activity. We then uncoupled the network by blocking all synaptic transmission (APV, CNQX, bicuculline and strychnine) and observed that β-PMTX increases both the intrinsic activity at individual channels and the number of intrinsically activated channels. At the cellular level, we found that β-PMTX has two effects: it switches 58% of the silent interneurons into spontaneously active interneurons and increases the firing rate of intrinsically spiking cells. Finally, we investigated the effect of β-PMTX on sodium currents. We found that this toxin not only affects the inactivation of INaT but also increases the peak amplitude of the persistent sodium current (INaP). Altogether, theses findings suggest that β-PMTX acting on INaP and INaT enhances intrinsic activity leading to a profound modulation of spontaneous rhythmic activity in spinal networks.

  1. Tectonics of China: Continental scale cataclastic flow

    Science.gov (United States)

    Gallagher, John J., Jr.

    inference is made from recently published plate tectonic interpretations. Geologic maps show that there are six elements and that each element has a Precambrian, crystalline core which is surrounded by upper Paleozoic continental margin suites of rocks, including subduction complexes, among others. Geologic data on ophiolites demonstrate that the brittle elements and their margins were juxtaposed and then welded together along suture zones during Permian and Triassic time to make China. Cenofcoic plate motions affecting China resulted in the collision with India where it converges with southwest China and the extension in eastern China where island arcs move away from the mainland and where grabens are actively forming. The juxtaposition to Siberia, which acts as a buttress against northern China, explains the compression of western China, and the absence of a buttress in the Pacific Ocean explains why eastern China can extend. Furthermore, laboratory data on the mechanical behavior of rock under conditions analogous to the shallow crustal conditions of interest in China show that all rocks are weaker in extension than they are in compression. Basement rock in western China is strong because it is compressed, but this same basement rock is weak in eastern China because it is in extension. The tectonics of China or, in mechanistic terms, the way in which the mechanical framework of China responds to Cenozoic boundary forces was a result of China's previous plate tectonic history. Crystalline cores are the rigid blocks that form brittle elements. Both the continental margin suites and the sutures are the ductile zones. The sutures and sediment patterns seen in the basins and ranges of China can be explained in terms of this tectonic scenario.

  2. Carrier phase shifted SPWM based on current sourced multi-modular converter for active power filter

    Institute of Scientific and Technical Information of China (English)

    王立乔; 李建林; 张仲超

    2004-01-01

    A novel current-source active power filter(APF)based on multi-modular converter with carrier phase-shifted SPWM(CPS-SPWM)technique is proposed.With this technique,the effect of equivalent high switching frequency converter is obtained with low switching frequency converter.It is very promising in current-source APF that adopt superconducting magnetic energy storage component.

  3. A Palladium-Binding Deltarhodopsin for Light-Activated Conversion of Protonic to Electronic Currents.

    Science.gov (United States)

    Soto-Rodríguez, Jessica; Hemmatian, Zahra; Josberger, Erik E; Rolandi, Marco; Baneyx, François

    2016-08-01

    Fusion of a palladium-binding peptide to an archaeal rhodopsin promotes intimate integration of the lipid-embedded membrane protein with a palladium hydride protonic contact. Devices fabricated with the palladium-binding deltarhodopsin enable light-activated conversion of protonic currents to electronic currents with on/off responses complete in seconds and a nearly tenfold increase in electrical signal relative to those made with the wild-type protein.

  4. Characteristics of helium isotopes in natural gas and its tectonic implication in Bohai Bay Basin

    Institute of Scientific and Technical Information of China (English)

    DING Weiwei; DAI Jinxin; YANG Shufeng; CHEN Hanlin

    2006-01-01

    Analysis on helium isotopes in natural gas in Bohai Bay Basin showed their mantle-origin indicated by high 3He/4He ratio. The span of 3He/4He ratio increased from west to east. This pattern implied a close relationship to the local tectonic setting. Bohai Bay Basin experienced intensive neo-tectonic activities in the Cenozoic. Widespread faulted-depressions and strong volcanic eruptions manifested its extensional tectonics. Abiogenic natural gas could be released from magmas and migrate upward through deep faults during the extension. Tectonic conditions in the area would favor upward invasion and reservation of mantle-originated helium. Furthermore, with decrease of convergence rate between the Pacific and the Eurasia Plate, the subduction slab of the Pacific Plate rolled back and became steeper, resulting in mantle flow and other tectonic activities migrating from west to east in nature, and caused the variation in isotopic helium ratios.

  5. Current-induced strength degradation of activated carbon spheres in carbon supercapacitors

    Science.gov (United States)

    Sun, Yuan; Chen, Rong; Lipka, Stephen M.; Yang, Fuqian

    2016-05-01

    Activated carbon microspheres (ACSs), which are prepared using hydrothermal synthesis and ammonia activation, are used as the active materials in the anode and cathode of electric double layer capacitors (EDLCs). The ACS-based EDLCs of symmetrical electrodes exhibit good stability and a high degree of reversibility over 2000 charge-discharge cycles for electric current up to 10 A g-1. The ACSs maintain a nongraphitized carbon structure after over 2000 charge-discharge cycles. Nanoindentation experiments are performed on the ACSs, which are electrochemically cycled in a voltage window of 0-1 V at three electric currents of 0.5, 5, and 10 A g-1. For the same indentation load, both the contact modulus and indentation hardness of the ACSs decrease with the increase of the electric current used in the electrical charging and discharging. These results suggest that there exists strength degradation introduced by the electric current. A larger electric current will cause more strength degradation than a smaller electric current.

  6. Effects of SDPNFLRF-amide (PF1) on voltage-activated currents in Ascaris suum muscle.

    Science.gov (United States)

    Verma, S; Robertson, A P; Martin, R J

    2009-02-01

    Helminth infections are of significant concern in veterinary and human medicine. The drugs available for chemotherapy are limited in number and the extensive use of these drugs has led to the development of resistance in parasites of animals and humans (Geerts and Gryseels, 2000; Kaplan, 2004; Osei-Atweneboana et al., 2007). The cyclooctadepsipeptide, emodepside, belongs to a new class of anthelmintic that has been released for animal use in recent years. Emodepside has been proposed to mimic the effects of the neuropeptide PF1 on membrane hyperpolarization and membrane conductance (Willson et al., 2003). We investigated the effects of PF1 on voltage-activated currents in Ascaris suum muscle cells. The whole cell voltage-clamp technique was employed to study these currents. Here we report two types of voltage-activated inward calcium currents: transient peak (I(peak)) and a steady-state (I(ss)). We found that 1microM PF1 inhibited the two calcium currents. The I(peak) decreased from -146nA to -99nA (P=0.0007) and the I(ss) decreased from -45nA to -12nA (P=0.002). We also found that PF1 in the presence of calcium increased the voltage-activated outward potassium current (from 521nA to 628nA (P=0.004)). The effect on the potassium current was abolished when calcium was removed and replaced with cobalt; it was also reduced at a higher concentration of PF1 (10microM). These studies demonstrate a mechanism by which PF1 decreases the excitability of the neuromuscular system by modulating calcium currents in nematodes. PF1 inhibits voltage-activated calcium currents and potentiates the voltage-activated calcium-dependent potassium current. The effect on a calcium-activated-potassium channel appears to be common to both PF1 and emodepside (Guest et al., 2007). It will be of interest to investigate the actions of emodepside on calcium currents to further elucidate the mechanism of action.

  7. Evaluation of reference current extraction methods for DSP implementation in active power filters

    Energy Technology Data Exchange (ETDEWEB)

    Vardar, K.; Akpinar, E.; Suergevil, T. [Dokuz Eylul University, Department of Electrical and Electronics Engineering, Kaynaklar Kampusu, 35160 Buca, Izmir (Turkey)

    2009-10-15

    Generation of current references constitutes an important part in the control of active power filters (APFs) used in power system, since any inaccuracy in reference currents yields to incorrect compensation. In this paper, harmonic detection methods for generating reference currents have been evaluated on the basis of three-phase balanced and unbalanced load currents processed in the digital signal processor (DSP). The advantages and disadvantages of several methods found in the literature have been discussed on the basis of simulation results. Three of these methods have been programmed in the TMS320F2812 digital signal processor (DSP) unit and their performances are evaluated from the viewpoint of practical considerations. Finally, instantaneous reactive power method to estimate the APF reference currents is implemented and its practical results obtained under balanced and unbalanced loads are given. (author)

  8. Detection of TRPV4 channel current-like activity in Fawn Hooded hypertensive (FHH) rat cerebral arterial muscle cells

    National Research Council Canada - National Science Library

    Debebe Gebremedhin; David X Zhang; Dorothee Weihrauch; Nnamdi N Uche; David R Harder

    2017-01-01

    ...) rat, known to display exaggerated KCa channel current activity and impaired myogenic tone, express TRPV4 channels at the transcript and protein level and exhibit TRPV4-like single-channel cationic current activity...

  9. Active power filter for medium voltage networks with predictive current control

    Energy Technology Data Exchange (ETDEWEB)

    Verne, Santiago A.; Valla, Maria I. [Laboratorio de Electronica Industrial, Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata and CONICET, La Plata (Argentina)

    2010-12-15

    A transformer less Shunt Active Power Filter (SAPF) for medium voltage distribution networks based on Multilevel Diode Clamped Inverter is presented in this paper. Converter current control is based on a Model Predictive strategy, which gives very fast current response. Also, the algorithm includes voltage balancing capability which is essential for proper converter operation. The presented current control algorithm is naturally applicable to converters with an arbitrary number of levels with reduced computational effort by virtue of the incorporation of switching restrictions which are necessary for reliable converter operation. The performance of the proposed algorithm is evaluated by means of computer simulations. (author)

  10. The Ecology of Urban Tectonics

    DEFF Research Database (Denmark)

    Beim, Anne; Hvejsel, Marie Frier

    2016-01-01

    This paper is related to previous research by the authors that examine the phenomenon of tectonics as architectural design theory and method. These studies have shown that the notion of tectonics at large is associated with exclusive architecture, and that, as a profession architects have...... to Frampton “only an arrière-garde has the capacity to cultivate a resistant, identity-giving culture while at the same time having discreet recourse to universal technique.” (Frampton 2002: 81). In addition he stresses that the arrière-garde is NOT to be understood as a conservative or sentimental state...... decorative” to use the words of Frampton (Frampton 2002:81). But as a critical theory that questions the methodological foundation of architectural practice; how we go about the task of uniting aesthetics and technique in the creation of viable living spaces?...

  11. Current and Future Research in Active Control of Lightweight, Flexible Structures Using the X-56 Aircraft

    Science.gov (United States)

    Ryan, John J.; Bosworth, John T.; Burken, John J.; Suh, Peter M.

    2014-01-01

    The X-56 Multi-Utility Technology Testbed aircraft system is a versatile experimental research flight platform. The system was primarily designed to investigate active control of lightweight flexible structures, but is reconfigurable and capable of hosting a wide breadth of research. Current research includes flight experimentation of a Lockheed Martin designed active control flutter suppression system. Future research plans continue experimentation with alternative control systems, explore the use of novel sensor systems, and experiments with the use of novel control effectors. This paper describes the aircraft system, current research efforts designed around the system, and future planned research efforts that will be hosted on the aircraft system.

  12. Current Research Activities in Drive System Technology in Support of the NASA Rotorcraft Program

    Science.gov (United States)

    Handschuh, Robert F.; Zakrajsek, James J.

    2006-01-01

    Drive system technology is a key area for improving rotorcraft performance, noise/vibration reduction, and reducing operational and manufacturing costs. An overview of current research areas that support the NASA Rotorcraft Program will be provided. Work in drive system technology is mainly focused within three research areas: advanced components, thermal behavior/emergency lubrication system operation, and diagnostics/prognostics (also known as Health and Usage Monitoring Systems (HUMS)). Current research activities in each of these activities will be presented. Also, an overview of the conceptual drive system requirements and possible arrangements for the Heavy Lift Rotorcraft program will be reviewed.

  13. Active to sterile neutrino mixing limits from neutral-current interactions in MINOS

    CERN Document Server

    Adamson, P; Ayres, D S; Backhouse, C; Barr, G; Bishai, M; Blake, A; Bock, G J; Boehnlein, D J; Bogert, D; Cavanaugh, S; Cherdack, D; Childress, S; Coelho, J A B; Coleman, S J; Corwin, L; Cronin-Hennessy, D; Danko, I Z; de Jong, J K; Devenish, N E; Diwan, M V; Dorman, M; Escobar, C O; Evans, J J; Falk, E; Feldman, G J; Frohne, M V; Gallagher, H R; Gomes, R A; Goodman, M C; Gouffon, P; Graf, N; Gran, R; Grant, N; Grzelak, K; Habig, A; Harris, D; Hartnell, J; Hatcher, R; Himmel, A; Holin, A; Huang, X; Hylen, J; Ilic, J; Irwin, G M; Isvan, Z; Jaffe, D E; James, C; Jensen, D; Kafka, T; Kasahara, S M S; Koizumi, G; Kopp, S; Kordosky, M; Kreymer, A; Lang, K; Lefeuvre, G; Ling, J; Litchfield, P J; Loiacono, L; Lucas, P; Mann, W A; Marshak, M L; Mayer, N; McGowan, A M; Mehdiyev, R; Meier, J R; Messier, M D; Miller, W H; Mishra, S R; Mitchell, J; Moore, C D; Morfín, J; Mualem, L; Mufson, S; Musser, J; Naples, D; Nelson, J K; Newman, H B; Nichol, R J; Nicholls, T C; Nowak, J A; Oliver, W P; Orchanian, M; Paley, J; Patterson, R B; Pawloski, G; Pearce, G F; Petyt, D A; Phan-Budd, S; Pittam, R; Plunkett, R K; Qiu, X; Ratchford, J; Raufer, T M; Rebel, B; Rodrigues, P A; Rosenfeld, C; Sanchez, H A Rubin M C; Schneps, J; Schreiner, P; Sharma, R; Shanahan, P; Sousa, A; Stamoulis, P; Strait, M; Tagg, N; Talaga, R L; Tetteh-Lartey, E; Thomas, J; Thomson, M A; Tinti, G; Toner, R; Torretta, D; Tzanakos, G; Urheim, J; Vahle, P; Viren, B; Walding, J J; Weber, A; Webb, R C; White, C; Whitehead, L; Wojcicki, S G; Zwaska, R

    2011-01-01

    Results are reported from a search for active to sterile neutrino oscillations in the MINOS long-baseline experiment, based on the observation of neutral-current neutrino interactions, from an exposure to the NuMI neutrino beam of $7.07\\times10^{20}$ protons on target. A total of 802 neutral-current event candidates is observed in the Far Detector, compared to an expected number of $754\\pm28\\rm{(stat.)}\\pm{37}\\rm{(syst.)}$ for oscillations among three active flavors. The fraction $f_s$ of disappearing \

  14. Single channel currents of different amplitude activated by glutamate in a tonic (slow) crayfish muscle.

    Science.gov (United States)

    Finger, W; Pareto, A

    1987-09-11

    Single channel currents were recorded by means of the patch-clamp technique from a tonic (slow) crayfish muscle in the presence of 5 mM glutamate. The experiments were carried out with 'Gigaohm-seals' in the 'cell-attached' mode at 15-17 degrees C. Five classes of single channel currents with different mean amplitudes were resolved: i1 = -0.75 +/- 0.43 (S.D.) pA, i2 = -1.4 +/- 0.4 pA, i3 = -3.5 +/- 0.63 pA, i4 = -8.5 +/- 0.92 pA and i5 approximately equal to 2 X i4, i2, i3 and i4 were recorded at resting membrane potential, Eo approximately equal to -80 mV (pipette potential Vp = 0), while i1 and i5 were recorded at 40 mV hyperpolarized to Eo (Vp = +40 mV). The current most frequently seen was i4 which is the excitatory glutamate-activated single channel current recorded previously by Franke et al. The membrane reversal potentials and channel conductances for i2 and i4 were estimated to be +60 mV (Eo + 140 mV), 13 pS for i2 and +40 mV (Eo + 120 mV), 80 pS for i4. It was assumed that up to 40 i1 currents could superpose in a single patch to generate a DC current of up to -30 pA with current fluctuations the intensity of which increased with the DC current amplitude. Often variable combinations of i1 to i4 currents could be recorded simultaneously in a single patch. In particular, simultaneous activity of i1, i4; i2, i4 and i3, i4 currents was observed in different single patches.

  15. Ionic current correlations underlie the global tuning of large numbers of neuronal activity attributes.

    Science.gov (United States)

    Zhao, Shunbing; Golowasch, Jorge

    2012-09-26

    Ionic conductances in identified neurons are highly variable. This poses the crucial question of how such neurons can produce stable activity. Coexpression of ionic currents has been observed in an increasing number of neurons in different systems, suggesting that the coregulation of ionic channel expression, by thus linking their variability, may enable neurons to maintain relatively constant neuronal activity as suggested by a number of recent theoretical studies. We examine this hypothesis experimentally using the voltage- and dynamic-clamp techniques to first measure and then modify the ionic conductance levels of three currents in identified neurons of the crab pyloric network. We quantify activity by measuring 10 different attributes (oscillation period, spiking frequency, etc.), and find linear, positive and negative relationships between conductance pairs and triplets that can enable pyloric neurons to maintain activity attributes invariant. Consistent with experimental observations, some of the features most tightly regulated appear to be phase relationships of bursting activity. We conclude that covariation (and probably a tightly controlled coregulation) of ionic conductances can help neurons maintain certain attributes of neuronal activity invariant while at the same time allowing conductances to change over wide ranges in response to internal or environmental inputs and perturbations. Our results also show that neurons can tune neuronal activity globally via coordinate expression of ion currents.

  16. Compressive Tectonics around Tibetan Plateau Edges

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhixin; Xu Jiren

    2009-01-01

    Various earthquake fault types, mechanism solutions, stress field, and other geophysical data were analyzed for study on the crust movement in the Tibetan plateau and its tectonic implications. The results show that numbers of thrust fault and strike-slip fault type earthquakes with strong compressive stress near NNE-SSW direction occurred in the edges around the plateau except the eastern boundary. Some normal faulting type earthquakes concentrate in the Central Tibetan plateau. The strikes of fault planes of thrust and strike-slip faulting earthquakes are almost in the E-W direction based on the analyses of the Wulff stereonet diagrams of fault plane solutions. This implies that the dislocation slip vectors of the thrust and strike-slip faulting type events have quite great components in the N-S direction. The compression motion mainly probably plays the tectonic active regime around the plateau edges. The compressive stress in N-S or NE-SW directions predominates earthquake occurrence in the thrust and strike-slip faulting event region around the plateau. The compressive motion around the Tibetan plateau edge is attributable to the northward motion of the Indian subcontinent plate. The northward motion of the Tibetan plateau shortened in the N-S direction encounters probably strong obstructions at the western and northern margins.

  17. Pharmacological activation of rapid delayed rectifier potassium current suppresses bradycardia-induced triggered activity in the isolated guinea pig heart

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Olesen, Søren-Peter; Grunnet, Morten

    2007-01-01

    arrhythmias. We present here data that support that NS3623 affects native I(Kr) and report the effects that activating this potassium current have in the intact guinea pig heart. In Langendorff-perfused hearts, the compound showed a concentration-dependent shortening of action potential duration, which...

  18. Induction of self awareness in dreams through frontal low current stimulation of gamma activity.

    Science.gov (United States)

    Voss, Ursula; Holzmann, Romain; Hobson, Allan; Paulus, Walter; Koppehele-Gossel, Judith; Klimke, Ansgar; Nitsche, Michael A

    2014-06-01

    Recent findings link fronto-temporal gamma electroencephalographic (EEG) activity to conscious awareness in dreams, but a causal relationship has not yet been established. We found that current stimulation in the lower gamma band during REM sleep influences ongoing brain activity and induces self-reflective awareness in dreams. Other stimulation frequencies were not effective, suggesting that higher order consciousness is indeed related to synchronous oscillations around 25 and 40 Hz.

  19. Emerging Possibilities and Insuperable Limitations of Exogeophysics: The Example of Plate Tectonics

    Science.gov (United States)

    Stamenković, Vlada; Seager, Sara

    2016-07-01

    To understand the evolution and the habitability of any rocky exoplanet demands detailed knowledge about its geophysical state and history—such as predicting the tectonic mode of a planet. Yet no astronomical observation can directly confirm or rule out the occurrence of plate tectonics on a given exoplanet. Moreover, the field of plate tectonics is still young—questioning whether we should study plate tectonics on exoplanets at this point in time. In this work, we determine the limitations and the emerging possibilities of exogeophysics, the science of connecting geophysics to exoplanets, on the example of plate tectonics. Assuming current uncertainties in model and planet parameters, we develop a qualitatively probabilistic and conservative framework to estimate on what kind of planets and where in the Galaxy plate tectonics might occur. This we achieve by modeling how plate yielding, the most critical condition needed for plate mobility and subduction, is affected by directly observable (planet mass, size) or indirectly, to some degree, assessable planet properties (structure and composition). Our framework not only highlights the importance of a planet’s chemistry for the existence of plate tectonics and the path toward practical exogeophysics but also demonstrates how exoplanet science can actually help to better understand geophysics and the fundamentals of plate tectonics on Earth itself.

  20. Temperature dependence of rapidly adapting mechanically activated currents in rat dorsal root ganglion neurons.

    Science.gov (United States)

    Jia, Zhanfeng; Ling, Jennifer; Gu, Jianguo G

    2012-08-01

    Rapidly adapting mechanically activated channels (RA) are expressed on somatosensory neurons and thought to play a role in mechanical transduction. Because mechanical sensations can be significantly affected by temperatures, we examined thermal sensitivity of RA currents in cultured dorsal root ganglion (DRG) neurons to see if RA channel activity is highly temperature-dependent. RA currents were evoked from DRG neurons by membrane displacements and recorded by the whole-cell patch-clamp recording technique. We found that RA currents were significantly enhanced by warming temperatures from 22 to 32 °C and reduced by cooling temperatures from 24 to 14 °C. RA channel activation exhibited steep temperature-dependence with a large temperature coefficient (Q10>5) and a high activation energy (Ea>30 kcal/mol). We further showed that RA channel activation by mechanical stimulation led to membrane depolarization, which could result in action potential firing at 22 °C or 32 °C but not at 14 °C. Taken together, our results provide the measurements of thermal dynamics and activation energy of RA channels, and suggest that a high energy barrier is present for RA channels to open. These findings are in agreement with temperature sensitivity of mechanical sensations in mammals.

  1. Osteoclast spreading kinetics are correlated with an oscillatory activation of a calcium-dependent potassium current.

    Science.gov (United States)

    Espinosa, Leon; Paret, Laurent; Ojeda, Carlos; Tourneur, Yves; Delmas, Pierre D; Chenu, Chantal

    2002-10-01

    Cell movement and spreading involve calcium-dependent processes and ionic channel activation. During bone resorption, osteoclasts alternate between spread, motile and resorptive phases. We investigated whether the electrical membrane properties of osteoclasts were linked to their membrane morphological changes. Rabbit osteoclasts were recorded by time-lapse videomicroscopy performed simultaneously with patch-clamp whole cell and single channel recordings. Original image analysis methods were developed and used to demonstrate for the first time an oscillatory activation of a spontaneous membrane current in osteoclasts, which is directly correlated to the membrane movement rate. This current was identified as a calcium-dependent potassium current (IK(Ca)) that is sensitive to both charybdotoxin and apamin and was generated by a channel with unitary conductance of approximately 25+/-2 pS. Blockade of this current also decreased osteoclast spreading and inhibited bone resorption in vitro, demonstrating a physiological role for this current in osteoclast activity. These results establish for the first time a temporal correlation between lamellipodia formation kinetics and spontaneous peaks of IK(Ca), which are both involved in the control of osteoclast spreading and bone resorption.

  2. Tectonic implications of Mars crustal magnetism.

    Science.gov (United States)

    Connerney, J E P; Acuña, M H; Ness, N F; Kletetschka, G; Mitchell, D L; Lin, R P; Reme, H

    2005-10-18

    Mars currently has no global magnetic field of internal origin but must have had one in the past, when the crust acquired intense magnetization, presumably by cooling in the presence of an Earth-like magnetic field (thermoremanent magnetization). A new map of the magnetic field of Mars, compiled by using measurements acquired at an approximately 400-km mapping altitude by the Mars Global Surveyor spacecraft, is presented here. The increased spatial resolution and sensitivity of this map provide new insight into the origin and evolution of the Mars crust. Variations in the crustal magnetic field appear in association with major faults, some previously identified in imagery and topography (Cerberus Rupes and Valles Marineris). Two parallel great faults are identified in Terra Meridiani by offset magnetic field contours. They appear similar to transform faults that occur in oceanic crust on Earth, and support the notion that the Mars crust formed during an early era of plate tectonics.

  3. Tectonics in the Northwestern West Philippine Basin

    Institute of Scientific and Technical Information of China (English)

    Ni Xianglong; Wu Shiguo; Shinjo Ryuichi

    2008-01-01

    The West Philippine basin (WPB) is a currently inactive marginal basin belonging to Philippine Sea plate, which has a complex formation history and various crust structures. Based on gravity, magnetic and seismic data, the tectonics in West Philippine basin is characterized by amagnma spreading stage and strike slip fractures. NNE trending Okinawa-Luzon fracture zone is a large fracture zone with apparent geomorphology and shows a right-handed movement. The results of joint gravity-magnetic-seismic inversion suggest that the Okinawa-Luzon fracture zone has intensive deformation and is a transform fault. Western existence of the NW trending fractures under Ryukyu Islands Arc is the main cause of the differences between south and north Okinawa Trough. The Urdaneta plateau is not a remained arc, but remnant of mantle plume although its lava chemistry is similar to oceanic island basalt (OIB).

  4. Cesium blockade of delayed outward currents and electrically induced pacemaker activity in mammalian ventricular myocardium.

    Science.gov (United States)

    Meier, C F; Katzung, B G

    1981-05-01

    The effects of Cs+, 5-25 mM, were studied in cat and guinea pig papillary muscles using voltage clamp and current clamp techniques. In solutions containing normal K+, the major effects of Cs+ were depolarization of the resting potential and reduction of the delayed outward current (ixl) between -80 and -20 mV. Both inward and outward portions of the isochronal current voltage relation (l-s clamps) were reduced by extracellular Cs+. This resulted in a substantial reduction of inward rectification and, by subtraction from the normal I-V relationship, the definition of a Cs+-sensitive component of current. Under current clamp conditions, 5-10 mM Cs+ produced a dose-dependent slowing of repetitive firing induced by depolarization. At higher concentrations (25 mM) the resting potential was depolarized and repetitive activity could not be induced by further depolarization. However, release of hyperpolarizing pulses was followed by prolonged bursts of repetitive action potentials, suggesting partial reversal of blockade or participation of another pacemaker process. The experimental results and a numerical simulation show that under readily attainable conditions, reduction in an outward pacemaker current may slow pacemaker activity.

  5. The Lord Howe Rise continental ribbon: a fragment of eastern Gondwana that reveals the drivers of continental rifting and plate tectonics

    Science.gov (United States)

    Saito, S.; Hackney, R. I.; Bryan, S. E.; Kimura, J. I.; Müller, D.; Arculus, R. J.; Mortimer, N. N.; Collot, J.; Tamura, Y.; Yamada, Y.

    2016-12-01

    Plate tectonics and resulting changes in crustal architecture profoundly influence global climate, oceanic circulation, and the origin, distribution and sustainability of life. Ribbons of continental crust rifted from continental margins are one product of plate tectonics that can influence the Earth system. Yet we have been unable to fully resolve the tectonic setting and evolution of huge, thinned, submerged, and relatively inaccessible continental ribbons like the Lord Howe Rise (LHR), which formed during Cretaceous fragmentation of eastern Gondwana. Thinned continental ribbons like the LHR are not easily explained or predicted by plate-tectonic theory. However, because Cretaceous rift basins on the LHR preserve the stratigraphy of an un-accreted and intact continental ribbon, they can help to determine whether plate motion is self-organised—passively driven by the pull of negatively-buoyant subducting slabs—or actively driven by convective flow in the mantle. In a self-organising scenario, the LHR formed in response to ocean-ward retreat of the long-lived eastern Gondwana subduction zone and linked upper-plate extension. In the mantle-driven scenario, the LHR resulted from rifting near the eastern edge of Gondwana that was triggered by processes linked to emplacement of a silicic Large Igneous Province. These scenarios can be distinguished using the ribbon's extensional history and the composition and tectonic affinity of igneous rocks within rift basins. However, current knowledge of LHR rift basins is based on widely-distributed marine and satellite geophysical data, limited dredge samples, and sparse shallow drilling (<600 m below-seafloor). This limits our ability to understand the evolution of extended continental ribbons, but a recent deep crustal seismic survey across the LHR and a proposed IODP deep stratigraphic well through a LHR rift basin provide new opportunities to explore the drivers behind rifting, continental ribboning and plate tectonics.

  6. Interleaved Buck Converter with Variable Number of Active Phases and a Predictive Current Sharing Scheme

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Garcia, O.; Oliver, J. A.

    2008-01-01

    The efficiency of an interleaved Buck converter is typically low at light load conditions because of the switching losses in each of the switching stages. Improvements in the converter efficiency can be achieved by dynamically changing the number of active phases depending on the load current...

  7. Research of resisting of the biological active point for constant and alternative current

    Directory of Open Access Journals (Sweden)

    S. N. Peregudov

    2008-05-01

    Full Text Available Is conducted research of resistance of biologically active point (BAT on a direct and variable current. Research results are presented. The estimation of intercommunication between resistance of skin and by an electromagnetic radiation in BAT is done. Is shown possibility of the use of experimental information for diagnostics of the state of human to the organism.

  8. Physiological consequences of transient outward K(+) current activation during heart failure in the canine left ventricle

    DEFF Research Database (Denmark)

    Cordeiro, Jonathan M; Callø, Kirstine; Moise, N Sydney

    2012-01-01

    Background: Remodeling of ion channel expression is well established in heart failure (HF). We determined the extent to which I(to) is reduced in tachypacing-induced HF and assessed the ability of an I(to) activator (NS5806) to recover this current. Method and results: Whole-cell patch clamp was ...

  9. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Energy Technology Data Exchange (ETDEWEB)

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  10. Urinary plasmin activates collecting duct ENaC current in preeclampsia

    DEFF Research Database (Denmark)

    Buhl, KB; Friis, Ulla Glenert; Svenningsen, Per;

    2012-01-01

    In nephrotic syndrome, plasminogen is aberrantly filtered from plasma to the urinary space and activated along the tubular system. In vitro, plasmin increases ENaC current by proteolytic cleavage of the γ-subunit. It was hypothesized that preeclampsia is associated with plasmin-dependent ability...

  11. Differential effects of the transient outward K(+) current activator NS5806 in the canine left ventricle

    DEFF Research Database (Denmark)

    Calloe, Kirstine; Soltysinska, Ewa; Jespersen, Thomas

    2009-01-01

    To examine the electrophysiological and molecular properties of the transient outward current (I(to)) in canine left ventricle using a novel I(to) activator, NS5806, I(to) was measured in isolated epicardial (Epi), midmyocardial (Mid) and endocardial (Endo) cells using whole-cell patch-clamp tech...

  12. Frequency Response Analysis of Current Controllers for Selective Harmonic Compensation in Active Power Filters

    DEFF Research Database (Denmark)

    Lascu, C.; Asiminoaei, L.; Boldea, I.;

    2009-01-01

    This paper compares four current control structures for selective harmonic compensation in active power filters. All controllers under scrutiny perform the harmonic compensation by using arrays of resonant controllers, one for the fundamental and one for each harmonic of interest, in order to ach...

  13. Active Flow Control of Lifting Surface With Flap-Current Activities and Future Directions

    Science.gov (United States)

    Ahmadi, G.; Marzocca, P.; Jha, R.; Alstorm, B.; Obied, S.; Kabir, P.; Shahrabi, A.

    2010-01-01

    The main objective is to develop effective control strategies for separation control of an airfoil with a single hinge flap. The specific objectives are: Develop an active control architecture for flow control around an airfoil with flap. Design, fabricate, a wind tunnel test of a high lift wing (with flap) with integrated actuators and sensors. Design, development and fabrication of synthetic jet actuators. Develop appropriate control strategy for application to the airfoil. Wind tunnel testing of the high lift wing at various angles of attack and flap positions with closed loop control.

  14. Upper plate deformation and seismic barrier in front of Nazca subduction zone : the Chololo Fault System and active tectonics along the Coastal Cordillera, southern Peru

    OpenAIRE

    Audin, Laurence; Lacan, P.; Tavera, H.; Bondoux, Francis

    2008-01-01

    The South America plate boundary is one of the most active subduction zone. The recent Mw=8.4 Arequipa 2001 earthquake ruptured the subduction plane toward the south over 400 km and stopped abruptly on the Ilo Peninsula. In this exact region, the subduction seismic crisis induced the reactivation of continental fault systems in the coastal area. We studied the main reactivated fault system that trends perpendicular to the trench by detailed mapping of fault related-geomorphic features. Also, ...

  15. Voltage Quality Enhancement and Fault Current Limiting with Z-Source based Series Active Filter

    Directory of Open Access Journals (Sweden)

    F. Gharedaghi

    2011-11-01

    Full Text Available In this study, series active filter or dynamic voltage restorer application is proposed for reduction of downstream fault current in addition to voltage quality enhancement. Recently, the application of Z-source inverter is proposed in order to optimize DVR operation. This inverter makes DVR to operate appropriately when the energy storage device’s voltage level severely falls. Here, the Z-source inverter based DVR is proposed to compensate voltage disturbance at the PCC and to reduce the fault current in downstream of DVR. By calculating instantaneous current magnitude in synchronous frame, control system recognizes if the fault exists or not, and determines whether DVR should compensate voltage disturbance or try to reduce the fault current. The proposed system is simulated under voltage sag and swell and short circuit conditions. The simulation results show that the system operates correctly under voltage sag and short circuit conditions.

  16. Research on Proximity Magnetic Field Influence in Measuring Error of Active Electronic Current Transformers

    Directory of Open Access Journals (Sweden)

    Wu Weijiang

    2016-01-01

    Full Text Available The principles of the active electronic current transformer (ECT are introduced, and the mechanism of how a proximity magnetic field can influence the measuring of errors is analyzed from the perspective of the sensor section of the ECT. The impacts on active ECTs created by three-phase proximity magnetic field with invariable distance and variable distance are simulated and analyzed. The theory and simulated analysis indicate that the active ECTs are sensitive to proximity magnetic field under certain conditions. According to simulated analysis, a product structural design and the location of transformers at substation sites are suggested for manufacturers and administration of power supply, respectively.

  17. Inhibition of the hyperpolarization-activated current (if) of rabbit SA node myocytes by niflumic acid.

    Science.gov (United States)

    Accili, E A; DiFrancesco, D

    1996-03-01

    The effects of the amphiphilic substance niflumic acid (NFA) were examined in myocytes isolated from the sino-atrial node of the rabbit heart. NFA (50 and 500 microM), for 30-60 s, produced a reversible negative chronotropic effect by reducing the rate of diastolic depolarization, suggesting an inhibitory effect on the hyperpolarization-activated pacemaker current (if). NFA (from 0.05 to 500 microM) inhibited if by modifying the current kinetics, without alteration of the conductance. This was shown by evidence indicating that: (1) NFA inhibited if during hyperpolarizing pulses to the mid-point of if activation but not at fully activating voltages; (2) the slope and reversal potential of the fully activated current/voltage (I/V) relation were not altered by NFA, indicating no change in slope conductance or ion selectivity; and (3) hyperpolarizing ramp protocols confirmed the lack of action of 50 microM NFA on the fully activated current and a shift of approximately -8 mV. Although similar to inhibition by acetylcholine (ACh), inhibition by NFA was only partly additive with the action of ACh and was not altered by atropine or pertussis toxin, both of which eliminated the action of ACh. The effect of NFA was present after stimulation of adenylate cyclase by forskolin and after inhibition of phosphodiesterase by isobutylmethylxanthine (IBMX). In cell-attached patch measurements, NFA applied externally did not affect if measured in the patch. Finally, application of NFA to the cytoplasmic side of excised patches did not alter the current in the absence or presence of adenosine 3',5'-cyclic monophosphate (cAMP). These results suggest an external, membrane-delimited action of NFA on if.

  18. Analysis of G-protein-activated inward rectifying K(+) (GIRK) channel currents upon GABAB receptor activation in rat supraoptic neurons.

    Science.gov (United States)

    Harayama, Nobuya; Kayano, Tomohiko; Moriya, Taiki; Kitamura, Naoki; Shibuya, Izumi; Tanaka-Yamamoto, Keiko; Uezono, Yasuhito; Ueta, Yoichi; Sata, Takeyoshi

    2014-12-03

    While magnocellular neurons in the supraoptic nucleus (SON) possess rich Gi/o-mediated mechanisms, molecular and cellular properties of G-protein-activated inwardly rectifying K(+) (GIRK) channels have been controversial. Here, properties of GIRK channels are examined by RT-PCR and whole-cell patch-clamp techniques in rat SON neurons. Patch clamp experiments showed that the selective GABAB agonist, baclofen, enhanced currents in a high K(+) condition. The baclofen-enhanced currents exhibited evident inward rectification and were blocked by the selective GABAB antagonist, CGP55845A, the IRK channel blocker, Ba(2+), and the selective GIRK channel blocker, tertiapin, indicating that baclofen activates GIRK channels via GABAB receptors. The GIRK currents were abolished by N-ethylmaleimide pretreatment, and prolonged by GTPγS inclusion in the patch pipette, suggesting that Gi/o proteins are involved. RT-PCR analysis revealed mRNAs for all four GIRK 1-4 channels and for both GABABR1 and GABABR2 receptors in rat SON. However, the concentration-dependency of the baclofen-induced activation of GIRK currents had an EC50 of 110 µM, which is about 100 times higher than that of baclofen-induced inhibition of voltage-dependent Ca(2+) channels. Moreover, baclofen caused no significant changes in the membrane potential and the firing rate. These results suggest that although GIRK channels can be activated by GABAB receptors via the Gi/o pathway, this occurs at high agonist concentrations, and thus may not be a physiological mechanism regulating the function of SON neurons. This property that the membrane potential receives little influence from GIRK currents seems to be uncommon for CNS neurons possessing rich Gi/o-coupled receptors, and could be a special feature of rat SON neurons. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Tectonic characterization of a potential high-level nuclear waste repository at Yucca Mountain, Nevada

    Science.gov (United States)

    Whitney, John W.; O'Leary, Dennis W.

    1993-01-01

    Tectonic characterization of a potential high-level nuclear waste repository at Yucca Mountain, Nevada, is needed to assess seismic and possible volcanic hazards that could affect the site during the preclosure (next 100 years) and the behavior of the hydrologic system during the postclosure (the following 10,000 years) periods. Tectonic characterization is based on assembling mapped geological structures in their chronological order of development and activity, and interpreting their dynamic interrelationships. Addition of mechanistic models and kinematic explanations for the identified tectonic processes provides one or more tectonic models having predictive power. Proper evaluation and application of tectonic models can aid in seismic design and help anticipate probable occurrence of future geologic events of significance to the repository and its design.

  20. April 7, 2009, Mw 5.5 aftershock of the L'Aquila earthquake: seismogenic fault geometry and its implication for the central Apennines active extensional tectonics (Italy).

    Science.gov (United States)

    Adinolfi, Guido Maria; Lavecchia, Giusy; De Matteis, Raffaella; Nardis Rita, De; Francesco, Brozzetti; Federica, Ferrarini; Zollo, Aldo

    2015-04-01

    On April 6, 2009 (at 01:32 UTC) a Mw 6.3 earthquake hit the town of L'Aquila (central Italy) and surrounding villages causing fatalities and severe damage in the area. After few days, a nearly 40-km-long extensional fault system was activated generating both northward and southward seismicity migration along the NW-SE trending sector of central Apennines. During the intense aftershocks sequence, different sesmogenic sources with a distinct geometry, size and the degree of involvement were reactivated. Among the relevant aftershocks with Mw 5.0 to 5.5, the largest one occurred on April 7 (at 17:47 UTC), 9 km SE-ward of the mainshock involving a source seated at much greater depths (~14 km). Despite the enormous number of studies of the 2009 L'Aquila earthquake, mainly focused on the various geological and seismological aspects of the main Paganica source, the April 7 strongest aftershock (Mw 5.5) has not yet been deeply investigated. Consistent geometric and kinematic correlations between the geological and seismological data about this seismogenic source are missing. There are still open questions concerning its unresolved geometry and the unknown style of the central Apennines structure activated at greater depths during the 2009 L'Aquila seismic sequence. Furthermore, some authors (Lavecchia et al., 2012) have supposed that the April 7, 2009 aftershock (Mw 5.5) occurred onto an high dip segment (~50°) of an east-dipping extensional basal detachment with a potential surface expression outcropping in the area of the eastern Sabina-Simbruini Mts. In this work we propose a seismological analysis of the April 7, 2009 aftershock (Mw 5.5) rupture process. In order to define the unresolved source geometry, we computed the focal mechanism through the time domain, moment tensor full waveform inversion (Dreger and Helmberger, 1993). Also, we estimated the apparent source time functions (ASTFs) by deconvolution of the impulse response of the medium from the recorded data

  1. Role of local to regional-scale collisions in the closure history of the Southern Neotethys, exemplified by tectonic development of the Kyrenia Range active margin/collisional lineament, N Cyprus

    Science.gov (United States)

    Robertson, Alastair; Kinnaird, Tim; McCay, Gillian; Palamakumbura, Romesh; Chen, Guohui

    2016-04-01

    Active margin processes including subduction, accretion, arc magmatism and back-arc extension play a key role in the diachronous, and still incomplete closure of the S Neotethys. The S Neotethys rifted along the present-day Africa-Eurasia continental margin during the Late Triassic and, after sea-floor spreading, began to close related to northward subduction during the Late Cretaceous. The northern, active continental margin of the S Neotethys was bordered by several of the originally rifted continental fragments (e.g. Taurides). The present-day convergent lineament ranges from subaqueous (e.g. Mediterranean Ridge), to subaerial (e.g. SE Turkey). The active margin development is partially obscured by microcontinent-continent collision and post-collisional strike-slip deformation (e.g. Tauride-Arabian suture). However, the Kyrenia Range, N Cyprus provides an outstanding record of convergent margin to early stage collisional processes. It owes its existence to strong localised uplift during the Pleistocene, which probably resulted from the collision of a continental promontory of N Africa (Eratosthenes Seamount) with the long-lived S Neotethyan active margin to the north. A multi-stage convergence history is revealed, mainly from a combination of field structural, sedimentological and igneous geochemical studies. Initial Late Cretaceous convergence resulted in greenschist facies burial metamorphism that is likely to have been related to the collision, then rapid exhumation, of a continental fragment (stage 1). During the latest Cretaceous-Palaeogene, the Kyrenia lineament was characterised by subduction-influenced magmatism and syn-tectonic sediment deposition. Early to Mid-Eocene, S-directed thrusting and folding (stage 2) is likely to have been influenced by the suturing of the Izmir-Ankara-Erzincan ocean to the north ('N Neotethys'). Convergence continued during the Neogene, dominated by deep-water terrigenous gravity-flow accumulation in a foredeep setting

  2. Hyperpolarization-Activated Current Induces Period-Doubling Cascades and Chaos in a Cold Thermoreceptor Model

    Science.gov (United States)

    Xu, Kesheng; Maidana, Jean P.; Caviedes, Mauricio; Quero, Daniel; Aguirre, Pablo; Orio, Patricio

    2017-01-01

    In this article, we describe and analyze the chaotic behavior of a conductance-based neuronal bursting model. This is a model with a reduced number of variables, yet it retains biophysical plausibility. Inspired by the activity of cold thermoreceptors, the model contains a persistent Sodium current, a Calcium-activated Potassium current and a hyperpolarization-activated current (Ih) that drive a slow subthreshold oscillation. Driven by this oscillation, a fast subsystem (fast Sodium and Potassium currents) fires action potentials in a periodic fashion. Depending on the parameters, this model can generate a variety of firing patterns that includes bursting, regular tonic and polymodal firing. Here we show that the transitions between different firing patterns are often accompanied by a range of chaotic firing, as suggested by an irregular, non-periodic firing pattern. To confirm this, we measure the maximum Lyapunov exponent of the voltage trajectories, and the Lyapunov exponent and Lempel-Ziv's complexity of the ISI time series. The four-variable slow system (without spiking) also generates chaotic behavior, and bifurcation analysis shows that this is often originated by period doubling cascades. Either with or without spikes, chaos is no longer generated when the Ih is removed from the system. As the model is biologically plausible with biophysically meaningful parameters, we propose it as a useful tool to understand chaotic dynamics in neurons. PMID:28344550

  3. Characteristics of chloride currents activated by noradrenaline in rabbit ear artery cells.

    Science.gov (United States)

    Amédée, T; Large, W A; Wang, Q

    1990-09-01

    1. Responses to noradrenaline were studied in isolated rabbit ear artery cells with the nystatin method of whole-cell patch-clamp recording. With this technique it was possible to obtain reproducible responses to noradrenaline which was not possible with traditional whole-cell recording. 2. With NaCl as the major constituent of the bathing solution (potassium-free pipette and external solutions) the reversal potential (Er) of the noradrenaline-evoked current was about 0 mV. When external chloride was replaced by thiocyanate, iodide, nitrate and bromide, Er was shifted to more negative potentials which indicates that a chloride conductance increase contributes to the current activated by noradrenaline. 3. When sodium was substituted by Tris, N-methyl-D-glucamine, choline or barium, Er of the noradrenaline-evoked current did not alter. This result suggests that a cation conductance is not implicated in the response to noradrenaline recorded with the nystatin method of whole-cell recording. 4. The chloride current activated by noradrenaline was blocked by the selective alpha 1-adrenoceptor antagonist prazosin but was not affected by the alpha 2-adrenoceptor antagonist yohimbine. 5. When cells were exposed to zero calcium bathing solutions the amplitude of the current elicited by noradrenaline was unaffected when measured within 1-2 min in zero calcium conditions. Continued exposure to 0 Ca + 1 mM-EGTA solution reversibly abolished the chloride current to noradrenaline. 6. In the presence of caffeine, which releases Ca2+ from internal stores and itself induced an inward current (at a holding potential of -50 mV), noradrenaline did not elicit a current. These data suggest that the chloride current evoked by noradrenaline results from an increase in intracellular concentration of calcium derived from internal stores. 7. The chloride channel blocking agents 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS; 0.5 mM) and furosemide (0.5 mM) produced partial

  4. Age, tectonic evolution and origin of the Aswa Shear Zone in Uganda: Activation of an oblique ramp during convergence in the East African Orogen

    Science.gov (United States)

    Saalmann, K.; Mänttäri, I.; Nyakecho, C.; Isabirye, E.

    2016-05-01

    The Aswa Shear Zone (ASZ) is a major NW-SE trending structure of over 1000 km length in East Africa. In Uganda, the ASZ is a steeply NE-dipping, up to 11 km wide mylonitic shear zone that shows multiple stage brittle reactivation. On outcrop-scale, the fabric in the ASZ is characterized by a well-developed NW-SE striking and subvertical or steeply NE or SW dipping mylonitic foliation and a subhorizontal to moderately NW- or SE-plunging stretching lineation. Sinistral kinematics and fabric are very consistent along strike. The strain is heterogeneously distributed and partitioned into lens-shaped lower strain zones dominated by folding and characterized by pure shear, which are surrounded by high strain zones, some of them thick ultramylonites, with intense simple shear combined with flattening and strong transposition of pre-existing fabrics. Ductile shearing occurred during bulk E-W shortening, commenced at amphibolite facies conditions and continued with similar kinematics at greenschist and even lower grade conditions. A number of (sub-)parallel shear zones occur to the NE and SW of the main zone at a distance of up to 20-45 km. They show similar fabrics and kinematics and are thus related to activity along ASZ reflecting strain partitioning into simple shear and pure shear domains on a regional scale. Samples of mylonitic gneisses from the shear zone have been analyzed with U-Pb LA-MC-ICPMS and show Neoarchaean crystallisation ages between 2.66 and 2.61 Ga. Timing of ductile sinistral shearing is poorly constrained by lower intercept ages of 686 ± 62 and 640 ± 44 Ma. The fabric and structural relationship of the ca. 660 Ma Adjumani Granite exposed in the northern segment of ASZ suggest that the age of shear activity can be further limited to ca. 685 and 655 Ma. The Aswa Shear Zone is interpreted as an intra-cratonic, crustal-scale structure close to the northeastern margin of the Congo Craton, possibly inherited from previous continental extension. Early Aswa

  5. Uniform Strike-Slip Rate along the Xianshuihe-Xiaojiang Fault System and Its Implications for Active Tectonics in Southeastern Tibet

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Recent studies on the Xianshuihe-Xiaojiang fault system suggest that the Late Quaternary strike-slip rate is approximately uniform along the entire length of the fault zone, about 15±2 mm/a.This approximately uniform strike slip rate strongly supports the clockwise rotation model of the southeastern Tibetan crust. By approximating the geometry of the arc-shaped Xianshuihe-Xiaojiang fault system as a portion of a small circle on a spherical Earth, the 15±2 mm/a strike slip rate corresponds to clockwise rotation of the Southeastern Tibetan Block at the (5.2±0.7)×10-7 deg/a angular velocity around the pole (21°N, 88°E) relative to the Northeast Tibetan Block. The approximately uniform strike slip rate along the Xianshuihe-Xiaojiang fault system also implies that the Longmenshan thrust zone is not active, or at least its activity has been very weak since the Late Quaternary. Moreover,the total offset along the Xianshuihe-Xiaojiang fault system suggests that the lateral extrusion of the Southeastern Tibetan Block relative to Northeastern Tibetan Block is about 160 km and 200-240 km relative to the Tarim-North China block. This amount of lateral extrusion of the Tibetan crust should have accommodated about 13-24% convergence between India and Eurasia based on mass balance calculations. Assuming that the slip rate of 15±2 mm/a is constant throughout the entire history of the Xianshuihe-Xiaojiang fault system, 11±1.5 Ma is needed for the Xianshuihe-Xiaojiang fault system to attain the 160 km of total offset. This implies that left-slip faulting on the Xianshuihe-Xiaojiang fault system might start at 11±1.5 Ma.

  6. The Effect of Water on the Flow of Stress-Activated Electric Currents through Rocks

    Science.gov (United States)

    Jahoda, A. M.; Cyr, G. G.; Dahlgren, R.; Freund, F. T.

    2011-12-01

    When igneous or high-grade metamorphic rocks are subjected to deviatoric stresses, dormant defects in the matrix of common rock-forming minerals become activated. These defects consist of pairs of oxygen anions in the 1- valence state, e.g. peroxy links such as O3Si-OO-SiO3. When a peroxy bond breaks, O3Si-O:O-SiO3, an electron is transferred from a neighboring O2- causing the donor oxygen, now O-, to turn into a defect electron, also known as a positive hole, that can propagate as a highly mobile positive charge through the rocks1. The current outflow is driven by the battery potential that builds up during this process. The question is how this electric current through rocks is affected by water. When positive holes flow into bulk water, they oxidize H2O to H2O2 and are thereby consumed2. This electrochemical reaction is driven by the potential drop across the rock-water interface. However, no such potential drop occurs across water that fills pores inside the rocks along the path of the electronic charge carriers. We present evidence that the presence of water in the pore space does indeed not "kill" the current flow. This observation leads to the conclusion that stress-activated positive hole currents should be able to flow through water-saturated rocks maybe as well as, possibly even better than through dry rocks. 1 Freund, F. T., et al.: Electric currents streaming out of stressed igneous rocks - A step towards understanding pre-earthquake low frequency EM emissions, Phys. Chem. Earth, 2006, 31, 389-396. 2 Balk, M., et al.: Oxidation of water to hydrogen peroxide at the rock-water interface due to stress-activated electric currents in rocks, Earth Planet. Sci. Lett. 2009, 283, 87-92

  7. Plate tectonics, habitability and life

    Science.gov (United States)

    Spohn, Tilman; Breuer, Doris

    2016-04-01

    The role of plate tectonics in defining habitability of terrestrial planets is being increasingly discussed (e.g., Elkins-Tanton, 2015). Plate tectonics is a significantly evolved concept with a large variety of aspects. In the present context, cycling of material between near surface and mantle reservoirs is most important. But increased heat transport through mixing of cold lithosphere with the deep interior and formation of continental crust may also matter. An alternative mechanism of material cycling between these reservoirs is hot-spot volcanism combined with crust delamination. Hot-spot volcanism will transport volatiles to the atmosphere while delamination will mix crust, possibly altered by sedimentation and chemical reactions, with the mantle. The mechanism works as long as the stagnant lithosphere plate has not grown thicker than the crust and as long as volcanic material is added onto the crust. Thermal evolution studies suggest that the mechanism could work for the first 1-2 Ga of planetary evolution. The efficiency of the mechanism is limited by the ratio of extrusive to intrusive volcanism, which is thought to be less than 0.25. Plate tectonics would certainly have an advantage by working even for more evolved planets. A simple, most-used concept of habitability requires the thermodynamic stability of liquid water on the surface of a planet. Cycling of CO2between the atmosphere, oceans and interior through subduction and surface volcanism is an important element of the carbonate-silicate cycle, a thermostat feedback cycle that will keep the atmosphere from entering into a runaway greenhouse. Calculations for a model Earth lacking plate tectonics but degassing CO2, N, and H2O to form a surface ocean and a secondary atmosphere (Tosi et al, 2016) suggest that liquid water can be maintained on the surface for 4.5Ga. The model planet would then qualify as habitable. It is conceivable that the CO2 buffering capability of its ocean together with silicate

  8. Tectonic Evolution of the Northern Continental Margin of North China Platform in Middle Proterozoic

    Institute of Scientific and Technical Information of China (English)

    Xu Zhongyuan; Liu Zhenghong

    2000-01-01

    An orogenic belt developed in late middle Proterozoic in the northern margin of North Chi