WorldWideScience

Sample records for striking right-lateral strike-slip

  1. Right-lateral shear and rotation as the explanation for strike-slip faulting in eastern Tibet

    Science.gov (United States)

    England, Philip; Molnar, Peter

    1990-01-01

    Bounds are placed here on the rate of rotation proposed by Cobbold and Davy (1988) for the major strike-slip faults in the eastern Tibetan Plateau. It is also concluded here that the image of lateral transport on such faults, known also as continental escape, extrusion, or expulsion, is an illusion, and that instead the left-lateral slip on east-striking plates in eastern Tibet is a manifestation of north-striking right-lateral simple shear. If this conclusion is correct, the east-striking left-lateral faults and the crustal blocks between them are rotating clockwise at 1-2 deg/Myr, the east-west dimension of eastern Tibet is shortening at 10-20 mm/yr, and little material is moving eastward out of India's path into Eursasia by left-lateral simple shear.

  2. THE ILICA BRANCH OF THE SOUTHEASTERN ESKIŞEHIR FAULT ZONE: AN ACTIVE RIGHT LATERAL STRIKE-SLIP STRUCTURE IN CENTRAL ANATOLIA, TURKEY

    Directory of Open Access Journals (Sweden)

    Korhan ESAT

    2016-12-01

    Full Text Available The Eskişehir Fault Zone is one of the prominent neotectonic structures of Turkey. It separates the west  Anatolian extensional province and the strike-slip induced northwest central Anatolian contractional area in the Anatolian Block. Its southeastern part is generally divided into three branches, namely the Ilıca, Yeniceoba, and Cihanbeyli from north to south, respectively. The right lateral strike-slip Ilıca branch (IB is an approximately 100-km-long fault and it is composed of several segments in a northwest-southeast direction. The slickensides, subsidiary fractures, cataclastic zone, fracture-controlled drainage pattern, right lateral stream deflections, deformation in the Quaternary unit observing in the seismic reflection sections, and seismicity of the region all indicate that the IB is an active right lateral strike-slip fault. The IB has also a regional tectonic importance as a boundary fault between the contractional and the extensional regions in central Anatolia considering that it is the southern limit of the contraction-related structures in the west-southwest of Ankara.

  3. Crimea-Kopet Dagh zone of concentrated orogenic deformations as a transregional late collisional right-lateral strike-slip fault

    Science.gov (United States)

    Patina, I. S.; Leonov, Yu. G.; Volozh, Yu. A.; Kopp, M. L.; Antipov, M. P.

    2017-07-01

    It is shown that the Crimea, Caucasus, and Kopet Dagh fold systems make up a single whole unified by a lithospheric strike-slip fault zone of concentrated dislocations. The strike-slip fault that dissects the sedimentary cover and consolidated crust is rooted in subcrustal layers of the mantle. The notions about strike-slip dislocations in the structure of the Crimea-Kopet Dagh System are considered. Comparative analysis of structure, age, and amplitude of strike-slip fault segments is carried out. The effect of strike-slip faulting on the deep-seated and near-surface structure of the Earth's crust is considered. Based on estimation of strike-slip offsets, the paleogeography of Paleogene basins is refined; their initial contours, which have been disturbed and fragmented by slipping motion strike-slip displacement, have been reconstructed.

  4. Characteristics of the Late Quaternary right-lateral strike-slip movement of Bolokenu-Aqikekuduk fault in northern Tianshan Mountains, NW China

    Directory of Open Access Journals (Sweden)

    Jun Shen

    2011-10-01

    A typical strain partitioning style in the compression area has developed between the intermontane Bo-A fault and the piedmont thrust structures of Northern Tianshan Mountains, under the effect of oblique compression, as indicated by the piedmont thrust structure and the strike-slip fault in the mountains.

  5. Active and recent strike-slip tectonics

    Science.gov (United States)

    Nur, Amos; Boccaletti, Mario

    An international workshop cosponsored by the Department of Geology, University of Florence, Italy and the Department of Geophysics, Stanford University, Stanford, Calif., was held in Florence, Italy, April 18-20, 1989,on the topic of active and recent strike-slip tectonics in the continental crust. Workshop participants from Turkey, Ethiopia, Israel, Greece, and various universities in Italy, Spain, West Germany, France, the United Kingdom, Brazil, and the United States reported on a broad range of studies involving strike-slip faulting in continental crustal setting. As it turned out, much of the work reported on involved aspects of strike-slip faulting that are only poorly understood, especially crustal deformation, which is distributed over a multiplicity of faults, or even fault domains.One of the rewarding aspects of this workshop was the diversity of geographic areas and geological settings covered by the reporters. The north and east Anatolian faults, the Dead Sea transform zone, western Turkey, north and central Greece, Malta, Sicily, southern Italy, the bethic Cordillera in southern Spain, Tunisia, Tibet and southwest China, offshore Brazil, Alaska, Nevada, and California. A recurring observation reported for all those areas was mixed mode faulting, i.e., the coterminous or sequential occurrence of strike-slip and normal faulting, or strike-slip and thrust, and in many instances also strikeslip, normal and thrust faulting in a single tectonic setting.

  6. Strike-slip tectonics during rift linkage

    Science.gov (United States)

    Pagli, C.; Yun, S. H.; Ebinger, C.; Keir, D.; Wang, H.

    2017-12-01

    The kinematics of triple junction linkage and the initiation of transforms in magmatic rifts remain debated. Strain patterns from the Afar triple junction provide tests of current models of how rifts grow to link in area of incipient oceanic spreading. Here we present a combined analysis of seismicity, InSAR and GPS derived strain rate maps to reveal that the plate boundary deformation in Afar is accommodated primarily by extensional tectonics in the Red Sea and Gulf of Aden rifts, and does not require large rotations about vertical axes (bookshelf faulting). Additionally, models of stress changes and seismicity induced by recent dykes in one sector of the Afar triple junction provide poor fit to the observed strike-slip earthquakes. Instead we explain these patterns as rift-perpendicular shearing at the tips of spreading rifts where extensional strains terminate against less stretched lithosphere. Our results demonstrate that rift-perpendicular strike-slip faulting between rift segments achieves plate boundary linkage during incipient seafloor spreading.

  7. The 2014 Mw6.9 Gokceada and 2017 Mw6.3 Lesvos Earthquakes in the Northern Aegean Sea: The Transition from Right-Lateral Strike-Slip Faulting on the North Anatolian Fault to Extension in the Central Aegean

    Science.gov (United States)

    Cetin, S.; Konca, A. O.; Dogan, U.; Floyd, M.; Karabulut, H.; Ergintav, S.; Ganas, A.; Paradisis, D.; King, R. W.; Reilinger, R. E.

    2017-12-01

    The 2014 Mw6.9 Gokceada (strike-slip) and 2017 Mw6.3 Lesvos (normal) earthquakes represent two of the set of faults that accommodate the transition from right-lateral strike-slip faulting on the North Anatolian Fault (NAF) to normal faulting along the Gulf of Corinth. The Gokceada earthquake was a purely strike-slip event on the western extension of the NAF where it enters the northern Aegean Sea. The Lesvos earthquake, located roughly 200 km south of Gokceada, occurred on a WNW-ESE-striking normal fault. Both earthquakes respond to the same regional stress field, as indicated by their sub-parallel seismic tension axis and far-field coseismic GPS displacements. Interpretation of GPS-derived velocities, active faults, crustal seismicity, and earthquake focal mechanisms in the northern Aegean indicates that this pattern of complementary faulting, involving WNW-ESE-striking normal faults (e.g. Lesvos earthquake) and SW-NE-striking strike-slip faults (e.g. Gokceada earthquake), persists across the full extent of the northern Aegean Sea. The combination of these two "families" of faults, combined with some systems of conjugate left-lateral strike-slip faults, complement one another and culminate in the purely extensional rift structures that form the large Gulfs of Evvia and Corinth. In addition to being consistent with seismic and geodetic observations, these fault geometries explain the increasing velocity of the southern Aegean and Peloponnese regions towards the Hellenic subduction zone. Alignment of geodetic extension and seismic tension axes with motion of the southern Aegean towards the Hellenic subduction zone suggests a direct association of Aegean extension with subduction, possibly by trench retreat, as has been suggested by prior investigators.

  8. Assemblage of strike-slip faults and tectonic extension and ...

    Indian Academy of Sciences (India)

    12

    and its effect on the productivity of the tight reservoirs. The study will not only guide. 95 the oil-gas ..... 5 Effect of tectonic extension and compression on coal reservoir productivity. 288. 5.1 Strike-slip compression and ..... staff of all the authors that cooperated in performing the analyses. We are also. 425 grateful to the ...

  9. Assemblage of strike-slip faults and tectonic extension and ...

    Indian Academy of Sciences (India)

    12

    Assemblage of strike-slip faults and tectonic. 1 extension and compression analysis: A case. 2 study of a Lower Permian commercial coal. 3 reservoir in China. 4. 5. Shuai Yina,*, Dawei Lvb, Zhonghu Wu c .... high-quality reservoirs, and tectonic action is a leading factor for oil and gas. 70 enrichment. Therefore, it is of great ...

  10. Propagation of strike-slip faults across Holocene volcano-sedimentary deposits, Pasto, Colombia

    Science.gov (United States)

    Rovida, Andrea; Tibaldi, Alessandro

    2005-10-01

    This study contributes to the understanding of shear failure development on the basis of macroscopic field data collected in latest Pleistocene-Holocene pyroclastic and fluvio-lacustrine deposits in the Pasto Valley, SW Colombia. Here there is a pervasive system of microfaults and joints. Right-lateral strike-slip microfaults strike N065°, whereas left-lateral strike-slip microfaults strike N120°. Three main joint sets strike N, N065° and N020° in decreasing order of frequency. Stress computation gives a horizontal σ1 trending ˜N060° and a horizontal σ3 trending ˜N150°, consistent with earthquake focal mechanisms and stress inversion of main faults. Synthetic shears dominate resulting from nucleation of older cracks. In the basement cropping out northeast of Pasto, the NE- to ENE-striking Buesaco, Aranda and Pasto Faults show evidence of latest Pleistocene-Holocene right-lateral strike-slip motions. The structures in the Pasto Valley can be interpreted as a Mode III damage zone representing the up-dip propagation of the main faults across the young volcano-sedimentary deposits.

  11. Strike-slip deformation reflects complex partitioning of strain in the Nankai Accretionary Prism (SE Japan)

    Science.gov (United States)

    Azevedo, Marco C.; Alves, Tiago M.; Fonseca, Paulo E.; Moore, Gregory F.

    2018-01-01

    Previous studies have suggested predominant extensional tectonics acting, at present, on the Nankai Accretionary Prism (NAP), and following a parallel direction to the convergence vector between the Philippine Sea and Amur Plates. However, a complex set of thrusts, pop-up structures, thrust anticlines and strike-slip faults is observed on seismic data in the outer wedge of the NAP, hinting at a complex strain distribution across SE Japan. Three-dimensional (3D) seismic data reveal three main families of faults: (1) NE-trending thrusts and back-thrusts; (2) NNW- to N-trending left-lateral strike-slip faults; and (3) WNW-trending to E-W right-lateral strike-slip faults. Such a fault pattern suggests that lateral slip, together with thrusting, are the two major styles of deformation operating in the outer wedge of the NAP. Both styles of deformation reflect a transpressional tectonic regime in which the maximum horizontal stress is geometrically close to the convergence vector. This work is relevant because it shows a progressive change from faults trending perpendicularly to the convergence vector, to a broader partitioning of strain in the form of thrusts and conjugate strike-slip faults. We suggest that similar families of faults exist within the inner wedge of the NAP, below the Kumano Basin, and control stress accumulation and strain accommodation in this latter region.

  12. Shell Tectonics: A Mechanical Model for Strike-slip Displacement on Europa

    Science.gov (United States)

    Rhoden, Alyssa Rose; Wurman, Gilead; Huff, Eric M.; Manga, Michael; Hurford, Terry A.

    2012-01-01

    We introduce a new mechanical model for producing tidally-driven strike-slip displacement along preexisting faults on Europa, which we call shell tectonics. This model differs from previous models of strike-slip on icy satellites by incorporating a Coulomb failure criterion, approximating a viscoelastic rheology, determining the slip direction based on the gradient of the tidal shear stress rather than its sign, and quantitatively determining the net offset over many orbits. This model allows us to predict the direction of net displacement along faults and determine relative accumulation rate of displacement. To test the shell tectonics model, we generate global predictions of slip direction and compare them with the observed global pattern of strike-slip displacement on Europa in which left-lateral faults dominate far north of the equator, right-lateral faults dominate in the far south, and near-equatorial regions display a mixture of both types of faults. The shell tectonics model reproduces this global pattern. Incorporating a small obliquity into calculations of tidal stresses, which are used as inputs to the shell tectonics model, can also explain regional differences in strike-slip fault populations. We also discuss implications for fault azimuths, fault depth, and Europa's tectonic history.

  13. Recent geodynamics of major strike-slip zones

    Directory of Open Access Journals (Sweden)

    Vladimir G. Trifonov

    2015-09-01

    In all of the cases mentioned above, strike-slip deformation was expressed only or mainly during strong earthquakes. At other times, the rate of its accumulation was small and the dominant stress conditions led to transverse shortening, rarely resulting in local lengthening of the tectonic zone. These variations are caused by the tectonic peculiarities of these zones. The sinistral component of the deformation is related to the shift of the Arabian Plate relative to the African one, but also the transverse component is related to the continental slope and is expressed by the Coastal range shortening that exists in the El Ghab segment zone. There is not only a dextral deformation component, but also a transverse component, expressed by shortening of the Fergana and Talas ranges existing in the Talas-Fergana fault zone. In both zones, the shortening component became appreciable or dominant when the strike-slip deformation rate decreased. Similar, but more local, relationships were expressed in the epicentral area of the 2003 Altai earthquake and in the Western Palmyrides.

  14. Onset of aseismic creep on major strike-slip faults

    KAUST Repository

    Çakir, Ziyadin

    2012-10-02

    Time series analysis of spaceborne synthetic aperture radar (SAR) data, GPS measurements, and fi eld observations reveal that the central section of the Izmit (Turkey) fault that slipped with a supershear rupture velocity in the A.D. 1999, Mw7.4, Izmit earthquake began creeping aseismically following the earthquake. Rapid initial postseismic afterslip decayed logarithmically with time and appears to have reached a steady rate comparable to the preearthquake full fault-crossing rate, suggesting that it may continue for decades and possibly until late in the earthquake cycle. If confi rmed by future monitoring, these observations identify postseismic afterslip as a mechanism for initiating creep behavior along strike-slip faults. Long-term afterslip and/or creep has signifi cant implications for earthquake cycle models, recurrence intervals of large earthquakes, and accordingly, seismic hazard estimation along mature strike-slip faults, in particular for Istanbul which is believed to lie adjacent to a seismic gap along the North Anatolian fault in the Sea of Marmara. © 2012 Geological Society of America.

  15. San Andreas-sized Strike-slip Fault on Europa

    Science.gov (United States)

    1998-01-01

    This mosaic of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, about the size of the California portion of the San Andreas fault, which runs from the California-Mexico border north to the San Francisco Bay. In a strike-slip fault, two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. Overall motion along the fault seems to have followed a continuous narrow crack along the feature's entire length, with a path resembling steps on a staircase crossing zones that have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. The fault's opposite sides can be reconstructed like a puzzle, matching the shape of the sides and older, individual cracks and ridges broken by its movements. [figure removed for brevity, see original site] The red line marks the once active central crack of the fault. The black line outlines the fault zone, including material accumulated in the regions which have been pulled apart. Bends in the fault have allowed the surface to be pulled apart. This process created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling-apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, in Death Valley and the Dead Sea. In those cases, the pulled-apart regions can include upwelled materials, but may be filled mostly by sedimentary and eroded material from above. One theory is that fault motion on Europa is induced by the pull of variable daily tides generated by Jupiter's gravitational tug on Europa. Tidal tension opens the fault and

  16. Strike-slip and extrusion tectonics of the Greater Caucasus-Kopetdagh region

    Science.gov (United States)

    Kopp, M. L.

    2012-04-01

    In the Paleogene-Early Miocene, the areas of the modern Greater Caucasus and Kopetdagh were occupied by marginal seas (parts of the Paratethys intracontinental sea) inheriting the Cretaceous back-arc basins. In the Early Miocene, a collisional compression of the seas began at the time when the Arabian plate detached from Africa to move northward. The compression proceeded in a good accordance with the Arabia movement that was manifested in a general synchroneity of the Late Alpine orogenies in the Caucasus and Kopetdagh with the rifting and spreading phases in the Aden Gulf and the Red Sea. The earliest orogeny was the Styrian one of the terminal Early Miocene. It corresponds to the initial stage of the rift opening and was mostly pronounced in the east, in Kopetdagh and East Iran, where a recent structure has been formed by the initial Middle Miocene. In the Greater Caucasus, the Styrian deformations occurred in its central part only (i.e., in front of the Arabian plate northern tip) where the main Caucasian thrusts and conjugate asymmetrical megaanticline of the Central Caucasus were formed. An essential feature of the earliest, Styrian, structure of the whole Caucasus-Kopetdagh region was a series of regional right-lateral strike-slip faults. In the Kopetdagh, the strike-slips have no submeridional but northwestern direction although they occurred in the northern continuation of the submeridional right-lateral strike-slip faults framing the Lut block. In the Caucasus, they became even sublatitudinal, in parallel with the North Anatolian fault, thus constituting a single domain with the latter. So, the right-lateral strike-slip faults of East Iran, Kopetdagh, and the Caucasus compose an extensive arc convex to the north and appeared probably as a result of the right-lateral shear caused by the known counterclockwise rotation of the Arabian lithospheric plate. The Middle Miocene was characterized by a tectonic pause both in the Red Sea-Aden rift system and in the

  17. The Strike-slip Systems in Northern Venezuela Review of Neotectonic, Paleoseismological and Seismic Investigations

    Science.gov (United States)

    Audemard, F.; Schmitz, M.; Levander, A.

    2006-12-01

    The complex Caribbean-South America plate boundary zone in northern Venezuela, which extends from the Southern Caribbean Deformation Front in the north to the Guayana Shield in the south, is the result of stress transfer generated by the relative movement of 2 cm/a between both plates. The movement is active since Cretaceous time and progressively migrates from west to east, and the major movement is accommodated along a roughly 1000 km long strike-slip system in northern Venezuela, comprising the Oca-Ancon, San Sebastian and El Pilar right-lateral fault systems. Neotoectonic and paleoseismological investigations have been carried out during the last two decades, and recently have been complemented by research activities within the interdisciplinary projects BOLIVAR (Broadband Ocean-Land Investigations of Venezuela and the Antilles arc Region) and GEODINOS (Recent Geodynamics of the Northern Limit of the South American Plate). By means of geological, seismicity and structural seismic investigations, the structures of the strike- slip zones are investigated from their surface expression through the crust and into the upper mantle. High velocity zones are identified at crustal levels and near surface investigations give insight to the detailed tectonic structures. Contribution from GEODINOS (FONACIT-2002000478) and BOLIVAR working groups.

  18. Multiple strike slip faults sets: A case study from the Dead Sea transform

    Science.gov (United States)

    Ron, Hagai; Nur, Amos; Eyal, Y.

    1990-01-01

    In many strike slip tectonic settings, large rotations of crust blocks about vertical axes have been inferred from paleomagnetic data. These blocks are bounded by sets of parallel faults which presumably accommodate the relative motion between the blocks as regional deformation progress. A mechanical model by Nur et al., (1986) suggests that rotations greater than phi sub c equals 25 to 45 degrees must be accommodated by more than one set of faults, with angle phi sub c between their direction; consequently the sum of the angles between sets must be roughly equal to the total tectonic material rotation. To test this model, the authors investigated the fault geometry and field relation of fault sets in the Mt. Hermon area in northern Israel, where paleomagnetic declination implies data 69 degrees plus or minus 13 degrees counter-clockwise block rotation. The statistical and field relation analysis of over 315 faults shows that the faulting is predominantly right lateral strike slip consisting of three distinct sets. The oldest set strikes 253 degrees, the second oldest set strikes 293 degrees and the youngest strikes 339 degrees. This last direction is consistent also with the current north-south direction of the maximum principle stress axis. The angle phi sub c between the first and second sets is 39 degrees and between the second and third sets 46 degrees, in good agreement with the phi sub c angle predicted from mechanical considerations. The sum of the two angles is 85 degrees, in good agreement with the 69 degrees plus or minus 13 degrees CCW paleomagnetically derived rotation. The results suggest specifically that the sequential development of multiple intersecting fault sets is responsible for the faulting in the Mt. Hermon area; and generally that the model of block rotation with multiple faults provides very good simple rules for analyzing very complex fault patterns.

  19. Neotectonics of a subduction/strike-slip transition: the northeastern Dominican Republic

    Energy Technology Data Exchange (ETDEWEB)

    Winslow, M.A.; McCann, W.R.

    1985-01-01

    The Septentrional fault system in the northeastern Dominican Republic marks the zone where the North American-Carribean plate boundary is evolving from subduction to strike-slip motion, and where terranes appear to be forming and migrating laterally in a subduction complex/forearc region. On the Island of Hispaniola, slip vectors are oblique to the strike of the Puerto Rico trench, and oblique subduction thrusts the upper plate over normal seafloor. The offshore geology and seismicity of the northern Caribbean suggest that uplift, broad crustal warping, thrusting, and strike-slip faulting (ie. collisional tectonics) should be present in the northern part of the Dominican Republic. The high topography (>1000m), high levels of seismicity, and large earthquakes support the hypothesis of contemporary deformation in Hispaniola. In this region, the subduction regime dies out toward the west, and deformation is transferred to onshore, oblique-slip faults. As this change in tectonic style has occurred in Neogene to Recent times, we are investigating the modern evolution of a plate boundary. We have already documented: (1) the presence of a strike-slip faulting in the northeastern Dominican Republic; (2) an anomalous push-up structure; and (3) a region of numerous splay faults. In conclusion, recent seismicity suggest a wide zone of deformation and variations in interplate motions near Hispaniola. This island lies at the western limit of active underthrusting and at the eastern limit of onshore faulting, i.e., at an important transition from a subduction to strike-slip regime.

  20. High tsunami frequency as a result of combined strike-slip faulting and coastal landslides

    Science.gov (United States)

    Hornbach, Matthew J.; Braudy, Nicole; Briggs, Richard W.; Cormier, Marie-Helene; Davis, Marcy B.; Diebold, John B.; Dieudonne, Nicole; Douilly, Roby; Frohlich, Cliff; Gulick, Sean P.S.; Johnson, Harold E.; Mann, Paul; McHugh, Cecilia; Ryan-Mishkin, Katherine; Prentice, Carol S.; Seeber, Leonardo; Sorlien, Christopher C.; Steckler, Michael S.; Symithe, Steeve Julien; Taylor, Frederick W.; Templeton, John

    2010-01-01

    Earthquakes on strike-slip faults can produce devastating natural hazards. However, because they consist predominantly of lateral motion, these faults are rarely associated with significant uplift or tsunami generation. And although submarine slides can generate tsunami, only a few per cent of all tsunami are believed to be triggered in this way. The 12 January Mw 7.0 Haiti earthquake exhibited primarily strike-slip motion but nevertheless generated a tsunami. Here we present data from a comprehensive field survey that covered the onshore and offshore area around the epicentre to document that modest uplift together with slope failure caused tsunamigenesis. Submarine landslides caused the most severe tsunami locally. Our analysis suggests that slide-generated tsunami occur an order-of-magnitude more frequently along the Gonave microplate than global estimates predict. Uplift was generated because of the earthquake's location, where the Caribbean and Gonave microplates collide obliquely. The earthquake also caused liquefaction at several river deltas that prograde rapidly and are prone to failure. We conclude that coastal strike-slip fault systems such as the Enriquillo-Plantain Garden fault produce relief conducive to rapid sedimentation, erosion and slope failure, so that even modest predominantly strike-slip earthquakes can cause potentially catastrophic slide-generated tsunami - a risk that is underestimated at present.

  1. A note on 2-D lithospheric deformation due to a blind strike-slip fault

    Indian Academy of Sciences (India)

    mic deformation. Several researchers have devel- oped models of coseismic lithospheric deformation. Rybicki (1971) found a closed-form analytical solu- tion for the problem of a long vertical strike-slip fault in a two-layer model of the earth. Chinnery and Jovanovich (1972) extended the solution to a three-layer model.

  2. Carpathian Shear Corridor – A strike-slip boundary of an extruded crustal segment

    Czech Academy of Sciences Publication Activity Database

    Marko, F.; Andriessen, P.A.M.; Tomek, Č.; Bezák, V.; Fojtíková, Lucia; Bošanský, M.; Piovarči, M.; Reichenwalder, P.

    703-704, APR 22 (2017), s. 119-134 ISSN 0040-1951 Grant - others:Slovak Foundation Grant(SK) VEGA 2/0188/15 Institutional support: RVO:67985891 Keywords : extrusion * Neo-alpine evolution * strike-slip faulting * uplift history * Western Carpathians Subject RIV: DC - Siesmology, Volcanology, Earth Structure OBOR OECD: Geology Impact factor: 2.693, year: 2016

  3. E–W strike slip shearing of Kinwat granitoid at South East Deccan ...

    Indian Academy of Sciences (India)

    R D Kaplay

    2017-07-21

    Jul 21, 2017 ... cO Indian Academy of Sciences. DOI 10.1007/s12040-017-0853-8. E–W strike slip shearing of Kinwat granitoid at South East. Deccan ...... shear zone, Sutlej section-structural geology and extrusion mechanism by various combinations of simple shear, pure shear and channel flow in shifting modes; Int. J.

  4. A note on 2-D lithospheric deformation due to a blind strike-slip fault

    Indian Academy of Sciences (India)

    Chinnery and Jovanovich (1972) extended the solution to a three-layer model. Savage and Prescott (1978) constructed a simple two-dimensional model of an earthquake cycle that takes place on a transform fault. Singh and Rani (1994) obtained an analytical solution for the problem of a long inclined strike- slip fault in an ...

  5. The Role of Near-Fault Relief in Creating and Maintaining Strike-Slip Landscape Features

    Science.gov (United States)

    Harbert, S.; Duvall, A. R.; Tucker, G. E.

    2016-12-01

    Geomorphic landforms, such as shutter ridges, offset river terraces, and deflected stream channels, are often used to assess the activity and slip rates of strike-slip faults. However, in some systems, such as parts of the Marlborough Fault System (South Island, NZ), an active strike-slip fault does not leave a strong landscape signature. Here we explore the factors that dampen or enhance the landscape signature of strike-slip faulting using the Channel-Hillslope Integrated Landscape Development model (CHILD). We focus on variables affecting the length of channel offsets, which enhance the signature of strike-slip motion, and the frequency of stream captures, which eliminate offsets and reduce this signature. We model a strike-slip fault that passes through a mountain ridge, offsetting streams that drain across this fault. We use this setup to test the response of channel offset length and capture frequency to fault characteristics, such as slip rate and ratio of lateral to vertical motion, and to landscape characteristics, such as relief contrasts controlled by erodibility. Our experiments show that relief downhill of the fault, whether generated by differential uplift across the fault or by an erodibility contrast, has the strongest effect on offset length and capture frequency. This relief creates shutter ridges, which block and divert streams while being advected along a fault. Shutter ridges and the streams they divert have long been recognized as markers of strike-slip motion. Our results show specifically that the height of shutter ridges is most responsible for the degree to which they create long channel offsets by preventing stream captures. We compare these results to landscape metrics in the Marlborough Fault System, where shutter ridges are common and often lithologically controlled. We compare shutter ridge length and height to channel offset length in order to assess the influence of relief on offset channel features in a real landscape. Based on our

  6. The Mechanics, Geometry and Distribution of Strike Slip Faults in a Fold and Thrust Belt, County Clare, Ireland

    Science.gov (United States)

    Nenna, F. A.; Aydin, A.

    2010-12-01

    Fundamental structures such as opening mode joints and veins, and closing mode pressure solution seams (PSSs) can form dense orthogonal arrays in collisional deformation belts and play important roles in the initiation and development of larger scale faults. We describe the deformation processes and the evolution of fault architecture using systematic documentation of field observations from arrays of strike-slip faults in the Carboniferous Ross Sandstone. This unit is exposed on the Loop Head Peninsula, County Clare, Ireland and was subject to compressive stresses associated with the Variscan orogeny at the end of the Carboniferous producing broad regional east-west trending folds and also tight low-amplitude folds cored by thrust faults. Near these faults, orthogonal sets of PSSs and joints/veins form contemporaneous arrays with pressure solution seams that are sub-parallel to the thrust fault traces and fold axes. A stress or material rotation during the Variscan Orogeny (or perhaps a major second stage of deformation either in late phase of the orogeny or post-orogeny) has lead to left-lateral shear of the PSSs evidenced by pressure solution splays and pull-aparts between their sheared segments, and right-lateral shear on the joints/veins evidenced by splay fractures. The splays of the sheared joints are in the same orientation of the joints in the pull-aparts of the sheared PSSs with which they merge. This indicates that the shearing of the joints/veins and the PSSs was likely to have occurred simultaneously under the same remote loading conditions. With increased shear, extensive splay fractures and pull-apart networks form weak damage zones through which strike-slip faults systems develop with slip of up to 2km. As a higher proportion of the shear is resolved on the joint system than that of the PSS system, the more prominent strike-slip faults are sub-parallel to or slightly inclined to the pre-existing joint/vein set and have a right-lateral sense of slip

  7. Lower Miocene coeval thrusting and strike-slip faulting in the Western Betics

    Science.gov (United States)

    Frasca, Gianluca; Gueydan, Frédéric; Brun, Jean-Pierre

    2015-04-01

    In the framework of the Africa-Europe convergence, the Mediterranean system presents a complex interaction between subduction rollback and upper subduction plate deformation since 30 Ma. The western end of the system shows an arcuate geometry across the Gibraltar arc, the Betico-Rifean belt, in which the relationship between slab dynamics and onshore tectonics is poorly constrained. The present study focuses on the Western Betics, which is characterized by two major thrusts: 1/ the Alboran Front limits the metamorphic domain (Alboran Domain) from the fold-and-thrust belts involving the Mesozoic cover of the Iberian margin (Subbetics Domain); 2/ the Alboran Internal Thrust allows the juxtaposition of a strongly attenuated lithosphere section, containing the large Ronda subcontinental mantle bodies, on top of crustal rocks. New structural data show that two major E-W strike-slip corridors controlled the deformation pattern of the Alboran Domain, in which E-W dextral strike-slip faults, N60° thrusts and N140° normal faults developed simultaneously during dextral strike-slip simple shear. The Alozaina piggy-back Basin, mainly formed by olistotromic deposits of Lower Miocene age, provides an age estimate for the continuous westward translation of the Alboran Domain, with reference to Iberia, that is accommodated mainly by an E-W lateral strike-slip ramp and a N60° frontal thrust ramp. In this context, a thrust sequence led to the piling up of thrust units in the Western Betics and to the crustal emplacement of the Ronda Peridotites bodies.

  8. The morphology of strike-slip faults - Examples from the San Andreas Fault, California

    Science.gov (United States)

    Bilham, Roger; King, Geoffrey

    1989-01-01

    The dilatational strains associated with vertical faults embedded in a horizontal plate are examined in the framework of fault kinematics and simple displacement boundary conditions. Using boundary element methods, a sequence of examples of dilatational strain fields associated with commonly occurring strike-slip fault zone features (bends, offsets, finite rupture lengths, and nonuniform slip distributions) is derived. The combinations of these strain fields are then used to examine the Parkfield region of the San Andreas fault system in central California.

  9. The cenozoic strike-slip faults and TTHE regional crust stability of Beishan area

    International Nuclear Information System (INIS)

    Guo Zhaojie; Zhang Zhicheng; Zhang Chen; Liu Chang; Zhang Yu; Wang Ju; Chen Weiming

    2008-01-01

    The remote sensing images and geological features of Beishan area indicate that the Altyn Tagh fault, Sanweishan-Shuangta fault, Daquan fault and Hongliuhe fault are distributed in Beishan area from south to north. The faults are all left-lateral strike-slip faults with trending of NE40-50°, displaying similar distribution pattern. The secondary branch faults are developed at the end of each main strike-slip fault with nearly east to west trending form dendritic oblique crossings at the angle of 30-50°. Because of the left-lateral slip of the branch faults, the granites or the blocks exposed within the branch faults rotate clockwisely, forming 'Domino' structures. So the structural style of Beishan area consists of the Altyn Tagh fault, Sanweishan-Shuangta fault, Daquan fault, Hongliuhe fault and their branch faults and rotational structures between different faults. Sedimentary analysis on the fault valleys in the study area and ESR chronological test of fault clay exhibit that the Sanweishan-Shuangta fault form in the late Pliocene (N2), while the Daquan fault displays formation age of l.5-1.2 Ma, and the activity age of the relevant branch faults is Late Pleistocene (400 ka). The ages become younger from the Altyn Tagh fault to the Daquan fault and strike-slip faults display NW trending extension, further revealing the lateral growth process of the strike-slip boundary at the northern margin during the Cenozoic uplift of Tibetan Plateau. The displacement amounts on several secondary faults caused by the activities of the faults are slight due to the above-mentioned structural distribution characteristics of Beishan area, which means that this area is the most stable active area with few seismic activities. We propose the main granitic bodies in Beishan area could be favorable preselected locations for China's high level radioactive waste repository. (authors)

  10. A note on 2-D lithospheric deformation due to a blind strike-slip fault

    Indian Academy of Sciences (India)

    Analytical solution for the problem of a surface-breaking long strike-slip fault in an elastic layer overlying an elastic half-space is well known. The purpose of this note is to obtain the corresponding solution for a blind fault. Since the solution is valid for arbitrary values of the fault-depth and the dip angle, the effects of these ...

  11. Transpressional segment boundaries in strike-slip fault systems offshore southern California: Implications for fluid expulsion and cold seep habitats

    Science.gov (United States)

    Maloney, Jillian M.; Grupe, Benjamin M.; Pasulka, Alexis L.; Dawson, Katherine S.; Case, David H.; Frieder, Christina A.; Levin, Lisa A.; Driscoll, Neal W.

    2015-05-01

    The importance of tectonics and fluid flow in controlling cold seep habitats has long been appreciated at convergent margins but remains poorly understood in strike-slip systems. Here we present geophysical, geochemical, and biological data from an active methane seep offshore from Del Mar, California, in the inner California borderlands (ICB). The location of this seep appears controlled by localized transpression associated with a step in the San Diego Trough fault zone and provides an opportunity to examine the interplay between fluid expulsion and restraining step overs along strike-slip fault systems. These segment boundaries may have important controls on seep locations in the ICB and other margins characterized by strike-slip faulting (e.g., Greece, Sea of Marmara, and Caribbean). The strike-slip fault systems offshore southern California appear to have a limited distribution of seep sites compared to a wider distribution at convergent plate boundaries, which may influence seep habitat diversity and connectivity.

  12. Magmatic control along a strike-slip volcanic arc: The central Aeolian arc (Italy)

    KAUST Repository

    Ruch, Joel

    2016-01-23

    The regional stress field in volcanic areas may be overprinted by that produced by magmatic activity, promoting volcanism and faulting. In particular, in strike-slip settings, the definition of the relationships between the regional stress field and magmatic activity remains elusive. To better understand these relationships, we collected stratigraphic, volcanic and structural field data along the strike-slip Central Aeolian arc (Italy): here the islands of Lipari and Vulcano separate the extensional portion of the arc (to the east) from the contractional one (to the west). We collected >500 measurements of faults, extension fractures and dikes at 40 sites. Most structures are NNE-SSW to NNW-SSE oriented, eastward dipping, and show almost pure dip-slip motion; consistent with an E-W extension direction, with minor dextral and sinistral shear. Our data highlight six eruptive periods during the last 55 ka, which allow considering both islands as a single magmatic system, in which tectonic and magmatic activity steadily migrated eastward and currently focus on a 10 km long x 2 km wide active segment. Faulting appears to mostly occur in temporal and spatial relation with magmatic events, supporting that most of the observable deformation derives from transient magmatic activity (shorter-term, days to months), rather than from steady longer-term regional tectonics (102-104 years). More in general, the Central Aeolian case shows how magmatic activity may affect the structure and evolution of volcanic arcs, overprinting any strike-slip motion with magma-induced extension at the surface.

  13. Aseismic strike-slip associated with the 2007 dike intrusion episode in Tanzania

    Science.gov (United States)

    Himematsu, Yuji; Furuya, Masato

    2015-08-01

    In July 2007, an earthquake swarm initiated in northern Tanzania near Lake Natron and lasted for about two months. Mt. Oldoinyo Lengai, located to the southwest of the swarm, began to erupt effusively about a month prior to the swarm, and increased its eruption intensity on September when the swarm almost ceased. Several previous studies have already reported the crustal deformation signals associated with the swarm using Interferometric Synthetic Aperture Radar (InSAR). However, nearly all the published data are based on the C-band ENVISAT/ASAR images acquired only from the descending path. We use the L-band ALOS/PALSAR images acquired from both ascending and descending paths, which allow us to examine the deformation signals in more detail. In addition to the InSAR data, we employ the offset-tracking technique to detect the signals along the azimuth direction. Using InSAR and offset-tracking data, we obtain the full 3D displacement fields associated with the episode. Besides the horizontal extension and subsidence signals due to the dike intrusion as already reported, the inferred full 3D displacements further indicate that the subsiding zone was horizontally moving by ~ 48 cm toward SSW. To explain the displacements, we performed fault source modeling, assuming an elastic half space. The fault slip distribution indicates that the contribution of the strike-slip component is about 20% of total moment release. Because almost all the focal mechanisms of earthquakes during the 2007 event indicate nearly pure normal faulting, aseismic strike-slip must have been responsible for the horizontal movement of the subsiding zone. The strike-slip at the shallowest depths suggests the presence of transtensive stress, which seems to be reasonable to generate the relay zones that are widely observed in the East African Rift. We also confirmed that the stress changes due to the dike intrusion were consistent with the inferred fault slip distributions.

  14. Source study of the Jan Mayen transform fault strike-slip earthquakes

    Science.gov (United States)

    Rodríguez-Pérez, Q.; Ottemöller, L.

    2014-07-01

    Seismic source parameters of oceanic transform zone earthquakes have been relatively poorly studied. Previous studies showed that this type of earthquakes has unique characteristics such as not only the relatively common occurrence of slow events with weak seismic radiation at high frequencies but also the occurrence of some events that have high apparent stress indicating strong high frequency radiation. We studied 5 strike-slip earthquakes in the Jan Mayen fracture zone with magnitudes in the range of 5.9 centroid time delay compared to other oceanic transform fault earthquakes.

  15. Holocene paleoearthquakes on the strike-slip Porters Pass Fault, Canterbury, New Zealand

    International Nuclear Information System (INIS)

    Howard, M.; Nicol, A.; Campbell, J.; Pettinga, J.R.

    2005-01-01

    The Porters Pass Fault comprises a series of discontinuous Holocene active traces which extend for c. 40 km between the Rakaia and Waimakariri Rivers in the foothills of the Southern Alps. There have been no historical earthquakes on the Porters Pass Fault (i.e., within the last 150 yr), and the purpose of this paper is to establish the timing and magnitudes of displacements on the fault at the ground surface during Holocene paleoearthquakes. Displaced geomorphic features (e.g., relict streams, stream channels, and ridge crests), measured using either tape measure (n = 20) or surveying equipment (n = 5), range from 5.5 to 33 m right lateral strike slip and are consistent with six earthquakes characterised by slip per event of c. 5-7 m. The timing of these earthquakes is constrained by radiocarbon dates from four trenches excavated across the fault and two auger sites from within swamps produced by ponding of drainage along the fault scarp. These data indicate markedly different Holocene earthquake histories along the fault length separated by a behavioural segment boundary near Lake Coleridge. On the eastern segment at least six Holocene earthquakes were identified at 8400-9000, 5700-6700, 4500-6000, 2300-2500, 800-1100, and 500-600 yr BP, producing an average recurrence interval of c. 1500 yr. On the western segment of the fault in the Rakaia River valley, a single surface-rupturing earthquake displaced Acheron Advance glacial deposits (c.10,000-14,000 yr in age) and may represent the southward continuation of the 2300-2500 yr event identified on the eastern segment. These data suggest Holocene slip rates of 3.2-4.1 mm/yr and 0.3-0.9 mm/yr on the eastern and western sections of the fault, respectively. Displacement and timing data suggest that earthquakes ruptured the western segment of the fault in no more than one-sixth of cases and that for a sample period of 10,000 yr the recurrence intervals were not characteristic. (auth). 45 refs., 10 figs., 3 tabs

  16. Strike-slip pull-apart process and emplacement of Xiangshan uranium-producing volcanic basin

    International Nuclear Information System (INIS)

    Qiu Aijin; Guo Lingzhi; Shu Liangshu

    2001-01-01

    Xiangshan volcanic basin is one of the famous uranium-producing volcanic basins in China. Emplacement mechanism of Xiangshan uranium-producing volcanic basin is discussed on the basis of the latest research achievements of deep geology in Xiangshan area and the theory of continental dynamics. The study shows that volcanic activity in Xiangshan volcanic basin may be divided into two cycles, and its emplacement is controlled by strike-ship pull-apart process originated from the deep regional faults. Volcanic apparatus in the first cycle was emplaced in EW-trending structure activated by clockwise strike-slipping of NE-trending deep fault, forming the EW-trending fissure-type volcanic effusion belt. Volcanic apparatus in the second cycle was emplaced at junction points of SN-trending pull-apart structure activated by sinistral strike-slipping of NE-trending deep faults and EW-trending basement faults causing the center-type volcanic magma effusion and extrusion. Moreover, the formation mechanism of large-rich uranium deposits is discussed as well

  17. How seismicity impacts the evolution and branching of strike-slip faults

    Science.gov (United States)

    Preuss, S.; van Dinther, Y.; Ampuero, J. P.; Herrendoerfer, R.; Gerya, T.

    2017-12-01

    Strike-slip fault systems are capable of producing large earthquakes on both their main fault and on secondary and potentially unknown faults. A recent example is the 2016 Mw 7.8 Kaikōura earthquake that resulted in surface ruptures along at least 12 major crustal faults. Strike-slip faults are surrounded by inelastic off-fault deformation zones whose displacement accounts for up to 60% of the total displacement. Secondary faults in California accommodate up to 43% of the total fault slip rate of mapped faults taken from the SCEC catalog, while unknown faults arguably accommodate up to 30% of the long-term strain. To better understand these complexities and the long-term evolution of branching fault structures, we quantify the parameters influencing branching structure with a particular focus on the role of seismicity. We incorporate the relevant dynamics of both long-term fault evolution and short-term seismogenesis using the continuum visco-elasto-plastic tools of Seismo-Thermo-Mechanical (STM) modeling approach (van Dinther et al., 2013, Herrendörfer et al., in prep). Long-term fault evolution is governed by Drucker-Prager plasticity and plastic strain weakening of cohesion, while frictional weakening and rapid slip is governed by either strongly rate-dependent (RDF) or rate-and-state friction (RSF). We use a 2D, plane view, natural scale model setup (1200 km x 1000 km), which contains the end of a dextral mature strike-slip fault on one side. Episodic slip events on this pre-existing fault patch propagate into the undamaged host rock. As faults grow they develop a fan-like plastic strain envelope, whose width keeps growing with fault length and accumulated on-fault slip. We interpret this zone as a splay-fault network, which is typically seen ahead of propagating fault tips. We analyze the evolving faults in terms of dissipated strain energy GC, accumulated slip D and fault length L. Results show that a single event is capable of producing a several hundreds

  18. Are "uncharacteristic" earthquakes spatially linked to strike-slip restraining bends?

    Science.gov (United States)

    Mann, P.

    2011-12-01

    On the basis of a compilation of paleoseismological data from the Wasatch and San Andreas faults, Schwartz and Coppersmith (1984) proposed that both plate boundary and intraplate faults tend to generate essentially same size earthquakes having a relatively narrow range of magnitudes near the maximum. They referred to these earthquakes as "characteristic earthquakes". Their hypothesis suggests that the historical record of earthquakes documented for periods of time ranging from centuries to millennia in different parts of the world that could allow predictions of future ruptures. The characteristic earthquake model works surprisingly well for major strike-slip faults like the North Anatolian fault of Turkey and the North Tabriz strike-slip fault in Iran which both show a progressive, uni-direction pattern of rupture starting at one point and "unzippering" over a distance of hundreds of kilometers in a series of earthquakes. This regular periodicity has been attributed to systematic changes in Coulomb failure stress on individual faults or interconnected fault networks defined by distinctive changes in fault strike, or stepover faults, or by the intersection of a neighboring fault. However, studies of the San Andreas, Wasatch, and Dead Sea faults show that earthquake ruptures are not periodic and instead form clusters of events with no obvious "recurrence interval" as predicted by the characteristic earthquake model. Some of these hard-to-forecast "uncharacteristic" earthquakes initiate as blind thrust faults formed at deeper levels in the crust near the brittle-plastic transition zone as illustrated by the 1989 M 6.9 Loma Prieta earthquake of California. Such events would produce little or no surface rupture of the main fault plane so the effects of this type of earthquake would remain impossible for future paleoseismologists to discern (other than from shaking effects and the broad vertical uplift related to vertical motions on deeply buried faults). More recently

  19. A preliminary study on surface ground deformation near shallow foundation induced by strike-slip faulting

    Science.gov (United States)

    Wong, Pei-Syuan; Lin, Ming-Lang

    2016-04-01

    According to investigation of recent earthquakes, ground deformation and surface rupture are used to map the influenced range of the active fault. The zones of horizontal and vertical surface displacements and different features of surface rupture are investigated in the field, for example, the Greendale Fault 2010, MW 7.1 Canterbury earthquake. The buildings near the fault rotated and displaced vertically and horizontally due to the ground deformation. Besides, the propagation of fault trace detoured them because of the higher rigidity. Consequently, it's necessary to explore the ground deformation and mechanism of the foundation induced by strike-slip faulting for the safety issue. Based on previous study from scaled analogue model of strike-slip faulting, the ground deformation is controlled by material properties, depth of soil, and boundary condition. On the condition controlled, the model shows the features of ground deformation in the field. This study presents results from shear box experiment on small-scale soft clay models subjected to strike-slip faulting and placed shallow foundations on it in a 1-g environment. The quantifiable data including sequence of surface rupture, topography and the position of foundation are recorded with increasing faulting. From the result of the experiment, first en echelon R shears appeared. The R shears rotated to a more parallel angle to the trace and cracks pulled apart along them with increasing displacements. Then the P shears crossed the basement fault in the opposite direction appears and linked R shears. Lastly the central shear was Y shears. On the other hand, the development of wider zones of rupture, higher rising surface and larger the crack area on surface developed, with deeper depth of soil. With the depth of 1 cm and half-box displacement 1.2 cm, en echelon R shears appeared and the surface above the fault trace elevated to 1.15 mm (Dv), causing a 1.16 cm-wide zone of ground-surface rupture and deformation

  20. Equivalent strike-slip earthquake cycles in half-space and lithosphere-asthenosphere earth models

    Science.gov (United States)

    Savage, J.C.

    1990-01-01

    By virtue of the images used in the dislocation solution, the deformation at the free surface produced throughout the earthquake cycle by slippage on a long strike-slip fault in an Earth model consisting of an elastic plate (lithosphere) overlying a viscoelastic half-space (asthenosphere) can be duplicated by prescribed slip on a vertical fault embedded in an elastic half-space. Inversion of 1973-1988 geodetic measurements of deformation across the segment of the San Andreas fault in the Transverse Ranges north of Los Angeles for the half-space equivalent slip distribution suggests no significant slip on the fault above 30 km and a uniform slip rate of 36 mm/yr below 30 km. One equivalent lithosphere-asthenosphere model would have a 30-km thick lithosphere and an asthenosphere relaxation time greater than 33 years, but other models are possible. -from Author

  1. A Possible Differentially Shortened Strike-slip Plate Boundary: the Okhotsk Plate Example.

    Science.gov (United States)

    Hindle, D.; Egorov, V.; Mackey, K. G.; Fujita, K.

    2004-12-01

    The Okhotsk plate has been postulated based on a combination of GPS geodetic inversions (REVEL1), seimsicity, geologic and lineament data. Lying between the North American and Eurasian plates, its northwestern corner would appear to be undergoing compression in a scissors motion between the two bounding plates. Extrusion tectonics along multiple, large strike-slip faults within the Okhotsk plate itself have been suggested to allow the escape of material away from the apex of Eurasia-North America. The plate boundary between Okhotsk and North America has been suggested to be diffuse, based on widely scattered minor seismicity. However, the large, left lateral, Ulakhan fault has also been suggested as a candidate plate boundary. We present field geological and geomorphological evidence of the partitioning of deformation between the Ulakhan fault, and several parallel and oblique, linked faults. The Ulakhan fault strand appears to have a maximum displacement of 24 km based on river valley offsets and closing large pull apart basins. Some of the displacement from the Ulakhan fault appears relayed into the plate margin along oblique trending, thrust/oblique slip faults. Estimated shortening over these faults is equivalent to the amount of shortening relayed into the plate margin from the plate boundary. There may be several thrust/oblique slip faults along the Ulakhan fault, which leads to the interesting situation of a segmented, strike-slip plate boundary being actively shortened in a margin parallel direction. This may be the result of postulated extrusion of the Okhotsk plate due to North America/Eurasia convergence. Such a situation would have important consequences for the interpretation of GPS data in a plate tectonic context.

  2. Continental strike slip fault zones in geologically complex lithosphere: the North Anatolian Fault, Turkey.

    Science.gov (United States)

    Cornwell, David; Thompson, David; Papaleo, Elvira; Rost, Sebastian; Houseman, Gregory; Kahraman, Metin; Turkelli, Niyazi; Teoman, Ugur; Altuncu Poyraz, Selda; Gulen, Levent; Utkucu, Murat

    2016-04-01

    As part of the multi-disciplinary Faultlab project, we present new detailed images in a geologically complex region where the crust and upper mantle is bisected by a major continental strike-slip fault system. Our study region samples the north Anatolian fault zone (NAFZ) near the epicentres of two large earthquakes that occurred in 1999 at Izmit (M7.5) and Düzce (M7.2) and where estimates of present day slip rate are 20-25 mm/yr. Using recordings of teleseismic earthquakes from a rectangular seismometer array spanning the NAFZ with 66 stations at a nominal inter-station spacing of 7 km and 7 additional stations further afield, we build a detailed 3-D image of structure and anisotropy using receiver functions, tomography and shear wave splitting and illuminate major changes in the architecture and properties of the upper crust, lower crust and upper mantle, both across and along the two branches of the NAFZ, at length scales of less than 20 km. We show that the northern NAFZ branch depth extent varies from the mid-crust to the upper mantle and it is likely to be less than 10 km wide. A high velocity lower crust and a region of crustal underthrusting appear to add strength to a heterogeneous crust and play a role in dictating the variation in faulting style and postseismic deformation. Sharp changes in lithospheric mantle velocity and anisotropy are constrained as the NAFZ is crossed, whereas crustal structure and anisotropy vary considerably both parallel and perpendicular to the faulting. We use our observations to test current models of the localisation of strike-slip deformation and develop new ideas to explain how narrow fault zones develop in extremely heterogeneous lithosphere.

  3. Fault and fracture patterns around a strike-slip influenced salt wall

    Science.gov (United States)

    Alsop, G. I.; Weinberger, R.; Marco, S.; Levi, T.

    2018-01-01

    The trends of faults and fractures in overburden next to a salt diapir are generally considered to be either parallel to the salt margin to form concentric patterns, or at right angles to the salt contact to create an overall radial distribution around the diapir. However, these simple diapir-related patterns may become more complex if regional tectonics influences the siting and growth of a diapir. Using the Sedom salt wall in the Dead Sea Fault system as our case study, we examine the influence of regional strike-slip faulting on fracture patterns around a salt diapir. This type of influence is important in general as the distribution and orientation of fractures on all scales may influence permeability and hence control fluid and hydrocarbon flow. Fractures adjacent to the N-S trending salt wall contain fibrous gypsum veins and injected clastic dykes, attesting to high fluid pressures adjacent to the diapir. Next to the western flank of the salt wall, broad (∼1000 m) zones of upturn or 'drape folds' are associated with NW-SE striking conjugate extensional fractures within the overburden. Within 300 m of the salt contact, fracture patterns in map view display a progressive ∼30°-35° clockwise rotation with more NNW-SSE strikes immediately adjacent to the salt wall. While some extensional faults display growth geometries, indicating that they were syn-depositional and initiated prior to tilting of beds associated with drape folding, other fractures display increasing dips towards the salt, suggesting that they have formed during upturn of bedding near the diapir. These observations collectively suggest that many fractures developed to accommodate rotation of beds during drape folding. Extensional fractures in the overburden define a mean strike that is ∼45° anticlockwise (counter-clockwise) of the N-S trending salt wall, and are therefore consistent with sinistral transtension along the N-S trending Sedom Fault that underlies the salt wall. Our outcrop

  4. The role of post-collisional strike-slip tectonics in the geological evolution of the late Neoproterozoic volcano-sedimentary Guaratubinha Basin, southern Brazil

    Science.gov (United States)

    Barão, Leonardo M.; Trzaskos, Barbara; Vesely, Fernando F.; de Castro, Luís Gustavo; Ferreira, Francisco J. F.; Vasconcellos, Eleonora M. G.; Barbosa, Tiago C.

    2017-12-01

    The Guaratubinha Basin is a late Neoproterozoic volcano-sedimentary basin included in the transitional-stage basins of the South American Platform. The aim of this study is to investigate its tectonic evolution through a detailed structural analysis based on remote sensing and field data. The structural and aerogeophysics data indicate that at least three major deformational events affected the basin. Event E1 caused the activation of the two main basin-bounding fault zones, the Guaratubinha Master Fault and the Guaricana Shear Zone. These structures, oriented N20-45E, are associated with well-defined right-lateral to oblique vertical faults, conjugate normal faults and vertical flow structures. Progressive transtensional deformation along the two main fault systems was the main mechanism for basin formation and the deposition of thick coarse-grained deposits close to basin-borders. The continuous opening of the basin provided intense intermediate and acid magmatism as well as deposition of volcaniclastic sediments. Event E2 characterizes generalized compression, recorded as minor thrust faults with tectonic transport toward the northwest and left-lateral activation of the NNE-SSW Palmital Shear Zone. Event E3 is related to the Mesozoic tectonism associated with the South Atlantic opening, which generated diabase dykes and predominantly right-lateral strike-slip faults oriented N10-50W. Its rhomboidal geometry with long axis parallel to major Precambrian shear zones, the main presence of high-angle, strike-slip or oblique faults, the asymmetric distribution of geological units and field evidence for concomitant Neoproterozoic magmatism and strike-slip movements are consistent with pull-apart basins reported in the literature.

  5. Influence of fault steps on rupture termination of strike-slip earthquake faults

    Science.gov (United States)

    Li, Zhengfang; Zhou, Bengang

    2018-03-01

    A statistical analysis was completed on the rupture data of 29 historical strike-slip earthquakes across the world. The purpose of this study is to examine the effects of fault steps on the rupture termination of these events. The results show good correlations between the type and length of steps with the seismic rupture and a poor correlation between the step number and seismic rupture. For different magnitude intervals, the smallest widths of the fault steps (Lt) that can terminate the rupture propagation are variable: Lt = 3 km for Ms 6.5 6.9, Lt = 4 km for Ms 7.0 7.5, Lt = 6 km for Ms 7.5 8.0, and Lt = 8 km for Ms 8.0 8.5. The dilational fault step is easier to rupture through than the compression fault step. The smallest widths of the fault step for the rupture arrest can be used as an indicator to judge the scale of the rupture termination of seismic faults. This is helpful for research on fault segmentation, as well as estimating the magnitude of potential earthquakes, and is thus of significance for the assessment of seismic risks.

  6. Analysis of the growth of strike-slip faults using effective medium theory

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, A.; Berryman, J.G.

    2009-10-15

    Increases in the dimensions of strike-slip faults including fault length, thickness of fault rock and the surrounding damage zone collectively provide quantitative definition of fault growth and are commonly measured in terms of the maximum fault slip. The field observations indicate that a common mechanism for fault growth in the brittle upper crust is fault lengthening by linkage and coalescence of neighboring fault segments or strands, and fault rock-zone widening into highly fractured inner damage zone via cataclastic deformation. The most important underlying mechanical reason in both cases is prior weakening of the rocks surrounding a fault's core and between neighboring fault segments by faulting-related fractures. In this paper, using field observations together with effective medium models, we analyze the reduction in the effective elastic properties of rock in terms of density of the fault-related brittle fractures and fracture intersection angles controlled primarily by the splay angles. Fracture densities or equivalent fracture spacing values corresponding to the vanishing Young's, shear, and quasi-pure shear moduli were obtained by extrapolation from the calculated range of these parameters. The fracture densities or the equivalent spacing values obtained using this method compare well with the field data measured along scan lines across the faults in the study area. These findings should be helpful for a better understanding of the fracture density/spacing distribution around faults and the transition from discrete fracturing to cataclastic deformation associated with fault growth and the related instabilities.

  7. Source characteristics of the 2015 Mw6.5 Lefkada, Greece, strike-slip earthquake

    Science.gov (United States)

    Melgar, Diego; Ganas, Athanassios; Geng, Jianghui; Liang, Cunren; Fielding, Eric J.; Kassaras, Ioannis

    2017-03-01

    We present a kinematic slip model from the inversion of 1 Hz GPS, strong motion, and interferometric synthetic aperture radar (InSAR) data for the 2015 Mw6.5 Lefkada, Greece, earthquake. We will show that most of the slip during this event is updip of the hypocenter (10.7 km depth) with substantial slip (>0.5 m) between 5 km depth and the surface. The peak slip is 1.6 m, and the inverted rake angles show predominantly strike-slip motion. Slip concentrates mostly to the south of the hypocenter, and the source time function indicates a total duration of 17 s with peak moment rate at 6 s. We will show that a 65° dipping geometry is the most plausible due to a lack of polarity reversals in the InSAR data and good agreement with Coulomb stress modeling, aftershock locations, and regional moment tensors. We also note that there was an 20 cm peak-to-peak tsunami observed at one tide gauge station 300 km away from the earthquake. We will discuss tsunami modeling results and study the possible source of the amplitude discrepancy between the modeled and the observed data at far-field tide gauges.

  8. Models of recurrent strike-slip earthquake cycles and the state of crustal stress

    Science.gov (United States)

    Lyzenga, Gregory A.; Raefsky, Arthur; Mulligan, Stephanie G.

    1991-01-01

    Numerical models of the strike-slip earthquake cycle, assuming a viscoelastic asthenosphere coupling model, are examined. The time-dependent simulations incorporate a stress-driven fault, which leads to tectonic stress fields and earthquake recurrence histories that are mutually consistent. Single-fault simulations with constant far-field plate motion lead to a nearly periodic earthquake cycle and a distinctive spatial distribution of crustal shear stress. The predicted stress distribution includes a local minimum in stress at depths less than typical seismogenic depths. The width of this stress 'trough' depends on the magnitude of crustal stress relative to asthenospheric drag stresses. The models further predict a local near-fault stress maximum at greater depths, sustained by the cyclic transfer of strain from the elastic crust to the ductile asthenosphere. Models incorporating both low-stress and high-stress fault strength assumptions are examined, under Newtonian and non-Newtonian rheology assumptions. Model results suggest a preference for low-stress (a shear stress level of about 10 MPa) fault models, in agreement with previous estimates based on heat flow measurements and other stress indicators.

  9. The Implications of Strike-Slip Earthquake Source Properties on the Transform Boundary Development Process

    Science.gov (United States)

    Neely, J. S.; Huang, Y.; Furlong, K.

    2017-12-01

    Subduction-Transform Edge Propagator (STEP) faults, produced by the tearing of a subducting plate, allow us to study the development of a transform plate boundary and improve our understanding of both long-term geologic processes and short-term seismic hazards. The 280 km long San Cristobal Trough (SCT), formed by the tearing of the Australia plate as it subducts under the Pacific plate near the Solomon and Vanuatu subduction zones, shows along-strike variations in earthquake behaviors. The segment of the SCT closest to the tear rarely hosts earthquakes > Mw 6, whereas the SCT sections more than 80 - 100 km from the tear experience Mw7 earthquakes with repeated rupture along the same segments. To understand the effect of cumulative displacement on SCT seismicity, we analyze b-values, centroid-time delays and corner frequencies of the SCT earthquakes. We use the spectral ratio method based on Empirical Green's Functions (eGfs) to isolate source effects from propagation and site effects. We find high b-values along the SCT closest to the tear with values decreasing with distance before finally increasing again towards the far end of the SCT. Centroid time-delays for the Mw 7 strike-slip earthquakes increase with distance from the tear, but corner frequency estimates for a recent sequence of Mw 7 earthquakes are approximately equal, indicating a growing complexity in earthquake behavior with distance from the tear due to a displacement-driven transform boundary development process (see figure). The increasing complexity possibly stems from the earthquakes along the eastern SCT rupturing through multiple asperities resulting in multiple moment pulses. If not for the bounding Vanuatu subduction zone at the far end of the SCT, the eastern SCT section, which has experienced the most displacement, might be capable of hosting larger earthquakes. When assessing the seismic hazard of other STEP faults, cumulative fault displacement should be considered a key input in

  10. Left-Lateral Strike-Slip Faulting in the East Alborz, NE Iran

    Science.gov (United States)

    Hollingsworth, J.; Walker, R.; Jackson, J.; Bolourchi, M. J.; Eshraghi, S. A.

    2006-12-01

    The East Alborz mountains of NE Iran are actively deforming as a result of Arabia-Eurasia collision. We combine observations of the geomorphology made using high resolution satellite, topographic and field data, with historical and recent seismicity to map major active faults in this poorly studied region. Deformation on the north side of the range occurs by range-normal shortening on the Khazar thrust fault, which separates Central Iran from the South Caspian. South of the range, deformation involves both left-lateral slip on the previously undocumented Shahrud fault system, which comprises several range-bounding fault segments, and shortening on (probably minor) thrust faults. Faulting south of the range is responsible for major historical earthquakes at Damghan (856AD) and Shahrud (1890). Deformation accommodated across the East Alborz is estimated from the difference in GPS velocities north and south of the range. South of the Alborz, northward GPS velocities across Central Iran decrease eastwards and the strike of the deforming belt changes to become more sub-parallel to the direction of South Caspian- Iran relative motion. This reduces the shortening component across the East Alborz, resulting in lower elevations between 54--57°E. West of 55.5°E, the more arc-normal shortening is achieved by partitioning of deformation onto the Khazar thrust (~1 mm/yr) and the Astaneh and Firuzkuh strike-slip faults (~3 mm/yr). East of 55.5°E, the Khazar fault ends and East Alborz deformation is accommodated primarily on the left-lateral Shahrud fault system, which may slip up to 3~mm/yr. Due to the long gap in seismicity along the eastern Shahrud fault system, the city of Jajarm (15,000 pop.) is considered at high risk from future earthquakes.

  11. Dynamics of a strike-slip fault analog model : Effects of the tectonic loading rate

    Science.gov (United States)

    Caniven, Y.; Dominguez, S.; Soliva, R.; Cattin, R.; Peyret, M.; Chéry, J.; Romano, C.

    2013-12-01

    The average seismic cycle duration extends from hundred to a few thousands years but geodetic measurements and seismological data extend over less than one century. This short time observation scale renders difficult to constrain the role of key parameters such as fault friction and geometry, crust rheology, stress and strain rate that control the kinematics and mechanics of active faults. To solve this time scale issue, we have developed a new experimental set-up that reproduces scaled micro-earthquakes and several hundreds of seismic cycles along a strike-slip fault. The model is constituted by two polyurethane foam plates laterally in contact, lying on a basal silicone layer, which simulate the mechanical behaviour of an elastoplastic upper crust over a ductile lower crust, respectively. To simulate the boundary conditions of a strike-slip fault, a computerized motoreductor system moves the two compartments on an opposite sens at a constant low velocity (a few μm/s). The model scaling, deduces from analog material physical parameters, implies that 1 cm in the model represents 2-3 km in the nature and 1 s is equivalent to 5-15 years. Surface-horizontal strain field is quantified by sub-pixel correlation of digital camera pictures recorded every 16 μm of displacement. We record about 2000 horizontal-velocity field measurements for each experiment. The analysis of model-interseismic and coseismic surface displacements and their comparison to seismogenic natural faults demonstrate that our analog model reproduces correctly both near and far-field surface strains. To compare the experiments, we have developed several algorithms that allow studying the main spatial and temporal evolution of the physical parameters and surface deformation processes that characterise the seismic cycle (magnitudes, stress, strain, friction coefficients, interseismic locking depth, recurrence time, ...). We also performed surface-velocity field inversions to assess the spatial

  12. Earthquake Activities Along the Strike-Slip Fault System on the Thailand-Myanmar Border

    Directory of Open Access Journals (Sweden)

    Santi Pailoplee

    2014-01-01

    Full Text Available This study investigates the present-day seismicity along the strike-slip fault system on the Thailand-Myanmar border. Using the earthquake catalogue the earthquake parameters representing seismic activities were evaluated in terms of the possible maximum magnitude, return period and earthquake occurrence probabilities. Three different hazardous areas could be distinguished from the obtained results. The most seismic-prone area was located along the northern segment of the fault system and can generate earthquakes of magnitude 5.0, 5.8, and 6.8 mb in the next 5, 10, and 50 years, respectively. The second most-prone area was the southern segment where earthquakes of magnitude 5.0, 6.0, and 7.0 mb might be generated every 18, 60, and 300 years, respectively. For the central segment, there was less than 30 and 10% probability that 6.0- and 7.0-mb earthquakes will be generated in the next 50 years. With regards to the significant infrastructures (dams in the vicinity, the operational Wachiralongkorn dam is situated in a low seismic hazard area with a return period of around 30 - 3000 years for a 5.0 - 7.0 mb earthquake. In contrast, the Hut Gyi, Srinakarin and Tha Thung Na dams are seismically at risk for earthquakes of mb 6.4 - 6.5 being generated in the next 50 years. Plans for a seismic-retrofit should therefore be completed and implemented while seismic monitoring in this region is indispensable.

  13. Strike-Slip Fault Patterns on Europa: Obliquity or Polar Wander?

    Science.gov (United States)

    Rhoden, Alyssa Rose; Hurford, Terry A.; Manga, Michael

    2011-01-01

    Variations in diurnal tidal stress due to Europa's eccentric orbit have been considered as the driver of strike-slip motion along pre-existing faults, but obliquity and physical libration have not been taken into account. The first objective of this work is to examine the effects of obliquity on the predicted global pattern of fault slip directions based on a tidal-tectonic formation model. Our second objective is to test the hypothesis that incorporating obliquity can reconcile theory and observations without requiring polar wander, which was previously invoked to explain the mismatch found between the slip directions of 192 faults on Europa and the global pattern predicted using the eccentricity-only model. We compute predictions for individual, observed faults at their current latitude, longitude, and azimuth with four different tidal models: eccentricity only, eccentricity plus obliquity, eccentricity plus physical libration, and a combination of all three effects. We then determine whether longitude migration, presumably due to non-synchronous rotation, is indicated in observed faults by repeating the comparisons with and without obliquity, this time also allowing longitude translation. We find that a tidal model including an obliquity of 1.2?, along with longitude migration, can predict the slip directions of all observed features in the survey. However, all but four faults can be fit with only 1? of obliquity so the value we find may represent the maximum departure from a lower time-averaged obliquity value. Adding physical libration to the obliquity model improves the accuracy of predictions at the current locations of the faults, but fails to predict the slip directions of six faults and requires additional degrees of freedom. The obliquity model with longitude migration is therefore our preferred model. Although the polar wander interpretation cannot be ruled out from these results alone, the obliquity model accounts for all observations with a value

  14. Viscoelastic shear zone model of a strike-slip earthquake cycle

    Science.gov (United States)

    Pollitz, F.F.

    2001-01-01

    I examine the behavior of a two-dimensional (2-D) strike-slip fault system embedded in a 1-D elastic layer (schizosphere) overlying a uniform viscoelastic half-space (plastosphere) and within the boundaries of a finite width shear zone. The viscoelastic coupling model of Savage and Prescott [1978] considers the viscoelastic response of this system, in the absence of the shear zone boundaries, to an earthquake occurring within the upper elastic layer, steady slip beneath a prescribed depth, and the superposition of the responses of multiple earthquakes with characteristic slip occurring at regular intervals. So formulated, the viscoelastic coupling model predicts that sufficiently long after initiation of the system, (1) average fault-parallel velocity at any point is the average slip rate of that side of the fault and (2) far-field velocities equal the same constant rate. Because of the sensitivity to the mechanical properties of the schizosphere-plastosphere system (i.e., elastic layer thickness, plastosphere viscosity), this model has been used to infer such properties from measurements of interseismic velocity. Such inferences exploit the predicted behavior at a known time within the earthquake cycle. By modifying the viscoelastic coupling model to satisfy the additional constraint that the absolute velocity at prescribed shear zone boundaries is constant, I find that even though the time-averaged behavior remains the same, the spatiotemporal pattern of surface deformation (particularly its temporal variation within an earthquake cycle) is markedly different from that predicted by the conventional viscoelastic coupling model. These differences are magnified as plastosphere viscosity is reduced or as the recurrence interval of periodic earthquakes is lengthened. Application to the interseismic velocity field along the Mojave section of the San Andreas fault suggests that the region behaves mechanically like a ???600-km-wide shear zone accommodating 50 mm/yr fault

  15. The San Andreas Fault and a Strike-slip Fault on Europa

    Science.gov (United States)

    1998-01-01

    The mosaic on the right of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, the size of the California portion of the San Andreas fault on Earth which runs from the California-Mexico border north to the San Francisco Bay. The left mosaic shows the portion of the San Andreas fault near California's san Francisco Bay that has been scaled to the same size and resolution as the Europa image. Each covers an area approximately 170 by 193 kilometers(105 by 120 miles). The red line marks the once active central crack of the Europan fault (right) and the line of the San Andreas fault (left). A strike-slip fault is one in which two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. The overall motion along the Europan fault seems to have followed a continuous narrow crack along the entire length of the feature, with a path resembling stepson a staircase crossing zones which have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. Opposite sides of the fault can be reconstructed like a puzzle, matching the shape of the sides as well as older individual cracks and ridges that had been broken by its movements. Bends in the Europan fault have allowed the surface to be pulled apart. This pulling-apart along the fault's bends created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, and in Death Valley and the Dead Sea. In those cases, the pulled apart regions can include upwelled materials, but may

  16. The San Andreas Fault and a Strike-slip Fault on Europa

    Science.gov (United States)

    1998-01-01

    The mosaic on the right of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, the size of the California portion of the San Andreas fault on Earth which runs from the California-Mexico border north to the San Francisco Bay. The left mosaic shows the portion of the San Andreas fault near California's san Francisco Bay that has been scaled to the same size and resolution as the Europa image. Each covers an area approximately 170 by 193 kilometers(105 by 120 miles). The red line marks the once active central crack of the Europan fault (right) and the line of the San Andreas fault (left). A strike-slip fault is one in which two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. The overall motion along the Europan fault seems to have followed a continuous narrow crack along the entire length of the feature, with a path resembling stepson a staircase crossing zones which have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. Opposite sides of the fault can be reconstructed like a puzzle, matching the shape of the sides as well as older individual cracks and ridges that had been broken by its movements. Bends in the Europan fault have allowed the surface to be pulled apart. This pulling-apart along the fault's bends created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, and in Death Valley and the Dead Sea. In those cases, the pulled apart regions can include upwelled materials, but may

  17. Role of N-S strike-slip faulting in structuring of north-eastern Tunisia; geodynamic implications

    Science.gov (United States)

    Arfaoui, Aymen; Soumaya, Abdelkader; Ben Ayed, Noureddine; Delvaux, Damien; Ghanmi, Mohamed; Kadri, Ali; Zargouni, Fouad

    2017-05-01

    Three major compressional events characterized by folding, thrusting and strike-slip faulting occurred in the Eocene, Late Miocene and Quaternary along the NE Tunisian domain between Bou Kornine-Ressas-Msella and Cap Bon Peninsula. During the Plio-Quaternary, the Grombalia and Mornag grabens show a maximum of collapse in parallelism with the NNW-SSE SHmax direction and developed as 3rd order distensives zones within a global compressional regime. Using existing tectonic and geophysical data supplemented by new fault-kinematic observations, we show that Cenozoic deformation of the Mesozoic sedimentary sequences is dominated by first order N-S faults reactivation, this sinistral wrench system is responsible for the formation of strike-slip duplexes, thrusts, folds and grabens. Following our new structural interpretation, the major faults of N-S Axis, Bou Kornine-Ressas-Messella (MRB) and Hammamet-Korbous (HK) form an N-S first order compressive relay within a left lateral strike-slip duplex. The N-S master MRB fault is dominated by contractional imbricate fans, while the parallel HK fault is characterized by a trailing of extensional imbricate fans. The Eocene and Miocene compression phases in the study area caused sinistral strike-slip reactivation of pre-existing N-S faults, reverse reactivation of NE-SW trending faults and normal-oblique reactivation of NW-SE faults, creating a NE-SW to N-S trending system of east-verging folds and overlaps. Existing seismic tomography images suggest a key role for the lithospheric subvertical tear or STEP fault (Slab Transfer Edge Propagator) evidenced below this region on the development of the MRB and the HK relay zone. The presence of extensive syntectonic Pliocene on top of this crustal scale fault may be the result of a recent lithospheric vertical kinematic of this STEP fault, due to the rollback and lateral migration of the Calabrian slab eastward.

  18. COMPARISON OF COSEISMIC IONOSPHERIC DISTURBANCE WAVEFORMS REVISITED: STRIKE-SLIP, NORMAL, AND REVERSE FAULT EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    Mokhamad Nur Cahyadi

    2015-02-01

    Full Text Available Using Total Electron Content (TEC measurements with Global Positioning System we studied ionospheric responses to three large earthquakes with difference focal mechanism that occurred in the Sumatra Andaman 26 December 2004, North off Sumatra 11 April 2012, and North Japan 7 December 2012. These earthquakes have different focal mechanisms, i.e. high-angle reverse, strike-slip, and normal faulting, respectively. TEC responses to the Sumatra Andaman 2004 and north Japan 2012 events initiated with positive changes. On the other hand, the initial TEC changes in the Sumatra 2012 earthquake showed both positive and negative polarities depending on the azimuth around the focal area. Such a variety may reflect differences in coseismic vertical crustal displacements, which are dominated by uplift and subsidence in the Sumatra 2012 event. This phenomena has same characteristic with 1994 Kuril Arch earthquake. There are three different propagation velocity in the Sumatra 2012 earthquake, within the first 300 km until 430 km, the CID propagation velocity was ~3 km/s, which is equal to the secod sound speed at the height of the ionospheric F-layer. Starting from 380 km until 750 km out from the epicenter, the disturbance seems to divide into two separate perturbations, with each propagating at a different velocity, about 1 km/s for the one and about 0.4 m/s for the other. The apparent velocity in the Sumatra Andaman 2004 and Japan 2012 propagated ~ 1 km/s and ~ 0.3 km/s, consistent with the sound speed at the ionospheric F layer height and internal gravity wave respectively. Resonant oscillation of TEC with a frequency of ~ 3.7 mHZ and ~4.4 mHz have been found in the Sumatra 2012 and Sumatra Andaman 2004 events. Those earthquakes, which occurred during a period of quiet geomagnetic activity, also showed clear preseismic TEC anomalies similar to those before the 2011 Tohoku-Oki and 2007 Bengkulu earthquake.   The positive anomalies started 30-60 minutes

  19. Strike-slip faulting in the Inner California Borderlands, offshore Southern California.

    Science.gov (United States)

    Bormann, J. M.; Kent, G. M.; Driscoll, N. W.; Harding, A. J.; Sahakian, V. J.; Holmes, J. J.; Klotsko, S.; Kell, A. M.; Wesnousky, S. G.

    2015-12-01

    In the Inner California Borderlands (ICB), offshore of Southern California, modern dextral strike-slip faulting overprints a prominent system of basins and ridges formed during plate boundary reorganization 30-15 Ma. Geodetic data indicate faults in the ICB accommodate 6-8 mm/yr of Pacific-North American plate boundary deformation; however, the hazard posed by the ICB faults is poorly understood due to unknown fault geometry and loosely constrained slip rates. We present observations from high-resolution and reprocessed legacy 2D multichannel seismic (MCS) reflection datasets and multibeam bathymetry to constrain the modern fault architecture and tectonic evolution of the ICB. We use a sequence stratigraphy approach to identify discrete episodes of deformation in the MCS data and present the results of our mapping in a regional fault model that distinguishes active faults from relict structures. Significant differences exist between our model of modern ICB deformation and existing models. From east to west, the major active faults are the Newport-Inglewood/Rose Canyon, Palos Verdes, San Diego Trough, and San Clemente fault zones. Localized deformation on the continental slope along the San Mateo, San Onofre, and Carlsbad trends results from geometrical complexities in the dextral fault system. Undeformed early to mid-Pleistocene age sediments onlap and overlie deformation associated with the northern Coronado Bank fault (CBF) and the breakaway zone of the purported Oceanside Blind Thrust. Therefore, we interpret the northern CBF to be inactive, and slip rate estimates based on linkage with the Holocene active Palos Verdes fault are unwarranted. In the western ICB, the San Diego Trough fault (SDTF) and San Clemente fault have robust linear geomorphic expression, which suggests that these faults may accommodate a significant portion of modern ICB slip in a westward temporal migration of slip. The SDTF offsets young sediments between the US/Mexico border and the

  20. Analog modeling of strike-slip surface ruptures: Implications for Greendale Fault (New Zealand) mechanics and paleoseismology

    Science.gov (United States)

    Sasnett, P.; Quigley, M.; Cruden, A. R.; Boutelier, D. A.; Villamor, P.

    2013-12-01

    Analog modeling of strike-slip faulting provides insight into the development and behavior of surface ruptures with progressive slip, with relevance for understanding how coseismic displacements from fault ruptures are recorded in paleoseismic trenches. Patterns of surface deformation were investigated in analogue experiments using cohesive and non-cohesive granular materials above a vertical, planar, strike-slip basement fault. Surface deformation during the experiments was monitored by 3D PIV (Particle Imaging Velocimetry) and 2D time-lapse photography. Analysis of the experiments focused on fault zone morphology and development, as well as comparisons between the models and surface deformation observed along the Greendale Fault that resulted from the 2010 Darfield earthquake, New Zealand. Complex surface rupture patterns with similar characteristics to the Greendale Fault (en echelon fractures, Riedel shears, pop-up structures, etc.) were generated by a simple fault plane of uniform dip, slip, and frictional properties. The main controls on surface rupture morphology were found to be the properties and thickness of the overburden, the nature of the material surface, and the overall displacement of the underlying fault. Mapping the evolution of fracture patterns with progressive shear strain reveals that Riedel shears, striking 0-30° from the underlying basement fault, are more frequently reactivated during multiple displacement (earthquake) cycles, and are thus most likely to provide reliable paleoseismic records. This information will assist in the identification of suitable locations for paleoseismic trenches and in the interpretation of trench records from the Greendale Fault and other active, strike-slip faults in analogous geologic settings. The results also highlight the tendency of trenching studies of faults of this type to underestimate the number of and displacements on previous ruptures, which potentially leads to an underestimate of the magnitude

  1. Strike-slip earthquakes in the oceanic lithosphere: Observations of exceptionally high apparent stress

    Science.gov (United States)

    Choy, George; McGarr, A.

    2002-01-01

    The radiated energies, ES, and seismic moments, M0, for 942 globally distributed earthquakes that occurred between 1987 to 1998 are examined to find the earthquakes with the highest apparent stresses (τa=μES/M0, where μ is the modulus of rigidity). The globally averaged τa for shallow earthquakes in all tectonic environments and seismic regions is 0.3 MPa. However, the subset of 49 earthquakes with the highest apparent stresses (τa greater than about 5.0 MPa) is dominated almost exclusively by strike-slip earthquakes that occur in oceanic environments. These earthquakes are all located in the depth range 7–29 km in the upper mantle of the young oceanic lithosphere. Many of these events occur near plate-boundary triple junctions where there appear to be high rates of intraplate deformation. Indeed, the small rapidly deforming Gorda Plate accounts for 10 of the 49 high-τa events. The depth distribution of τa, which shows peak values somewhat greater than 25 MPa in the depth range 20–25 km, suggests that upper bounds on this parameter are a result of the strength of the oceanic lithosphere. A recently proposed envelope for apparent stress, derived by taking 6 per cent of the strength inferred from laboratory experiments for young (less than 30 Ma) deforming oceanic lithosphere, agrees well with the upper-bound envelope of apparent stresses over the depth range 5–30 km. The corresponding depth-dependent shear strength for young oceanic lithosphere attains a peak value of about 575 MPa at a depth of 21 km and then diminishes rapidly as the depth increases. In addition to their high apparent stresses, which suggest that the strength of the young oceanic lithosphere is highest in the depth range 10–30 km, our set of high-τa earthquakes show other features that constrain the nature of the forces that cause interplate motion. First, our set of events is divided roughly equally between intraplate and transform faulting with similar depth distributions

  2. Structural setting and kinematics of Nubian fault system, SE Western Desert, Egypt: An example of multi-reactivated intraplate strike-slip faults

    Science.gov (United States)

    Sakran, Shawky; Said, Said Mohamed

    2018-02-01

    Detailed surface geological mapping and subsurface seismic interpretation have been integrated to unravel the structural style and kinematic history of the Nubian Fault System (NFS). The NFS consists of several E-W Principal Deformation Zones (PDZs) (e.g. Kalabsha fault). Each PDZ is defined by spectacular E-W, WNW and ENE dextral strike-slip faults, NNE sinistral strike-slip faults, NE to ENE folds, and NNW normal faults. Each fault zone has typical self-similar strike-slip architecture comprising multi-scale fault segments. Several multi-scale uplifts and basins were developed at the step-over zones between parallel strike-slip fault segments as a result of local extension or contraction. The NNE faults consist of right-stepping sinistral strike-slip fault segments (e.g. Sin El Kiddab fault). The NNE sinistral faults extend for long distances ranging from 30 to 100 kms and cut one or two E-W PDZs. Two nearly perpendicular strike-slip tectonic regimes are recognized in the NFS; an inactive E-W Late Cretaceous - Early Cenozoic dextral transpression and an active NNE sinistral shear.

  3. Strike-slip tectonics within the northernmost Philippine Sea plate in an arc-continent collisional setting

    Science.gov (United States)

    Gong, Wei; Jiang, Xiaodian; Guo, Yufan; Xing, Junhui; Li, Congying; Sun, Yang

    2017-09-01

    The geological processes in the northernmost Philippine Sea plate, which is bounded by the Suruga and Sagami troughs, are a typical example of an active collision zone. We attempt to illustrate the stress field through seismic estimations and geodetic analysis and propose the kinematic mode of the northernmost tip of the Philippine Sea plate. Seven events (M ≥ 4.0) are chosen for waveform inversion by the ISOLA software to distinguish the stress field. In particular, six of the chosen events, which exhibit strike-slip motion, are distributed in the eastern area, where few focal mechanisms have been reported by previous studies. According to the available focal mechanisms, strike-slip faults with similar P and T axes are widely distributed in the study area. The stress inversion suggests that the northern area is characterized by a NW-SE compression and a NE-SW extension stress regime, although some spatial differences exist. As indicated by an analysis of the geodesy, epicenters, focal mechanisms, gravity anomalies and velocity structure, the deformation in the northernmost tip is mainly accommodated by several conjugate strike-slip fault systems with steep dips that center on the Izu volcanic line. Generally, the maximum principal stress of the kinematics is derived from the collision between the Philippine Sea plate and Central Japan. Because of the different subduction angles, rates and directions of the down-going plate, diverging slab-pull forces along the Suruga and Sagami troughs may be causing the NE-NNE extension in most of the areas that are bounded by the two troughs. The extension propagates southwards along the Izu volcanic line and reaches the area adjacent to Miyake-jima.

  4. Late Pleistocene-Holocene Activity of the Strike-slip Xianshuihe Fault Zone, Tibetan Plateau, Inferred from Tectonic Landforms

    Science.gov (United States)

    Lin, A.; Yan, B.

    2017-12-01

    Knowledges on the activity of the strike-slip fault zones on the Tibetan Plateau have been promoted greatly by the interpretation of remote sensing images (Molnar and Tapponnier, 1975; Tapponnier and Molnar, 1977). The active strike-slip Xianshuihe-Xiaojiang Fault System (XXFS), with the geometry of an arc projecting northeastwards, plays an important role in the crustal deformation of the Tibetan Plateau caused by the continental collision between the Indian and Eurasian plates. The Xianshuihe Fault Zone (XFZ) is located in the central segment of the XXFS and extends for 370 km, with a maximum sinistral offset of 60 km since 13‒5 Ma. In this study, we investigated the tectonic landforms and slip rate along the central segment of the left-lateral strike-slip XFZ. Field investigations and analysis of ttectonic landforms show that horizontal offset has been accumulated on the topographical markers of different scales that developed since the Last Glacial Maximum (LGM). The central segment of the XFZ is composed of three major faults: Yalahe, Selaha, and Zheduotang faults showing a right-stepping echelon pattern, that is characterized by systematical offset of drainages, alluvial fans and terrace risers with typical scissoring structures, indicating a structural feature of left-lateral strike-slip fault. Based on the offset glacial morphology and radiocarbon dating ages, we estimate the Late Pleistocene-Holocene slip rate to be 10 mm/yr for the central segment of the XFZ, which is consistent with that estimated from the GPS observations and geological evidence as reported previously. Across the central segment of the XFZ, the major Selaha and Zheduotang faults participate a slip rate of 5.8 mm/yr and 3.4 mm/yr, respectively. Detailed investigations of tectonic landforms are essential for the understanding the activity of active faults. Our findings suggest that the left-lateral slipping of the XFZ partitions the deformation of eastward extrusion and northeastward

  5. Structural evolution of the La Trocha fault zone: Oblique collision and strike-slip basins in the Cuban Orogen

    Science.gov (United States)

    Cruz-Orosa, Israel; Sã Bat, Francesc; Ramos, Emilio; Rivero, LluíS.; VáZquez-Taset, Yaniel M.

    2012-10-01

    The La Trocha fault zone acted as a major left-lateral transfer zone and is bounded by the La Trocha (LTF), Zaza-Tuinicú (ZTF), Cristales (CTF) and Taguasco (TGF) faults. These faults were consistent with the clockwise rotation of convergence and shortening in central Cuba. From the Paleocene to the Early Eocene (65-48 Ma), a SSW-NNE shortening produced transtension in the LTF and transpression in the ZTF. Subsequently, during the Middle Eocene (48-37 Ma), shortening shifted to a SW-NE direction, resulting in the normal component of the LTF and transpression in the ZTF and CTF. Since the Late Eocene (37 Ma), central Cuba has been welded to the North American Plate. The post-welding deformation gave rise to transtension of the LTF and TGF. This deformation is consistent with a WSW-ENE shortening and reflects activity in the transform boundary of the Cayman Trough. Both the normal and thrust displacements of these previous faults are corroborated by structural data whereas left-lateral displacement is deduced from the concordance between oblique collision and structural features. Plate-kinematics and the structural evolution of the La Trocha fault zone indicate that the related Central Basin is a strike-slip polygenetic basin and that the formation of this system (i.e., fault zone - strike-slip basin) was a consequence of the Paleogene oblique collision between the Caribbean Volcanic Arc and the Bahamas Borderland (North American plate).

  6. Three-dimensional shuffling of horses in a strike-slip duplex: an example from the Lambertville sill, New Jersey

    Science.gov (United States)

    Laney, Stephen E.; Gates, Alexander E.

    1996-06-01

    Detailed analysis of a dextral strike-slip duplex within the relatively isotropic rocks of the Lambertville sill, New Jersey indicates that horses have experienced vertical, horizontal and oblique movements resulting from extrusional shuffling within a restraining bend. This is the first documentation of the three-dimensional movement of horses within a strike-slip duplex. Deformation within the duplex shows a complex system of early synthetic fractures and reverse faults followed by antithetic fractures which dissect previously continuous slab-shaped horses into diamond-shaped lenses. Most faults are oblique slip. Antithetic fault movements and clockwise rigid rotation of horses dominate the south half of the duplex and synthetic movements and counterclockwise rotations dominate the north half. Slickenline plunges on curved horse-bounding fault surfaces within the duplex range from nearly horizontal to 40° resulting in both lateral movements (middle) to normal movements (tails) on a single horse. Curved slickensides commonly have opposite senses of movement on either side of individual horses indicating relative emergence or submergence. Such a geometry could also result from a group of horses moving in the same oblique direction but at different rates. These complex extrusional-type movements were observed in both cross-sectional and plan views. The net result of the movements is a contraction or flattening of the duplex normal to the bounding faults. The horses shifted to accommodate this flattening as overall displacement was transferred between the bounding faults along curved internal faults.

  7. Kinematics of transition from subduction to strike-slip: an example from the New Zealand plate boundary (Invited)

    Science.gov (United States)

    Wallace, L. M.; Barnes, P.; Beavan, R. J.; van Dissen, R.; Pondard, N.; Litchfield, N. J.; Lamarche, G.; Little, T. A.

    2009-12-01

    We develop a kinematic model for the transition from oblique subduction beneath the North Island to strike-slip in the South Island, New Zealand, constrained by GPS velocities and onshore and new offshore active fault slip rate and location data. To interpret these data, we simultaneously invert the kinematic data for poles of rotation of tectonic blocks (block boundaries chosen to coincide with known active faults) and the degree of interseismic coupling on faults in the region, including the Hikurangi subduction thrust. Our best-fitting kinematic models require that the northeastern corner of the South Island undergoes significant vertical axis rotation as a part of the rapidly rotating (3-4°/Myr) North Island forearc block, while the remainder of the tectonic blocks in the South Island undergo negligible vertical axis rotation relative to the Pacific Plate. This result agrees well with clockwise paleomagnetic declinations from ~4 Ma rock samples in the northeastern South Island, and suggests that paleomagnetically-observed rotation of that region is continuing today. The poles of rotation between the more rapidly rotating northeastern South Island blocks and the non-rotating South Island blocks (further south) coincide with the boundary between the rotating and non-rotating domains of the South Island. This result is consistent with structural mapping of the rotation/non-rotation boundary by Little and Roberts (1997), and suggests that the transition from the rapidly rotating forearc of the Hikurangi subduction margin to a strike-slip dominated plate boundary in the South Island is accommodated by a crustal-scale kink or hinge in the upper plate of that subduction zone. This result highlights a remarkable consistency between datasets spanning decades (GPS), thousands of years (active fault data), and millions of years (paleomagnetic data and bedrock structure) in the northeastern South Island. Although the interseismic coupling coefficients that we estimate for

  8. A PHYSICAL MODEL OF THE EFFECT OF A SHALLOW WEAK LAYER ON STRONG GROUND MOTION FOR STRIKE-SLIP RUPTURES

    Energy Technology Data Exchange (ETDEWEB)

    JAMES N. BRUNE AND ABDOLRASOOL ANOOSHEHPOOR

    1998-02-23

    We report results of foam-rubber modeling of the effect of a shallow weak layer on ground motion from strike-slip ruptures. Computer modeling of strong ground motion from strike-slip earthquakes has involved somewhat arbitrary assumptions about the nature of slip along the shallow part of the fault (e.g., fixing the slip to be zero along the upper 2 kilometers of the fault plane) in order to match certain strong motion accelerograms. Most modeling studies of earthquake strong ground motion have used what is termed kinematic dislocation modeling. In kinematic modeling the time function for slip on the fault is prescribed, and the response of the layered medium is calculated. Unfortunately, there is no guarantee that the model and the prescribed slip are physically reasonable unless the true nature of the medium and its motions are known ahead of time. There is good reason to believe that in many cases faults are weak along the upper few kilometers of the fault zone and may not be able to maintain high levels of shear strain required for high dynamic energy release during earthquakes. Physical models of faulting, as distinct from numerical or mathematical models, are guaranteed to obey static and dynamic mechanical laws. Foam-rubber modeling studies have been reported in a number of publications. The object of this paper is to present results of physical modeling using a shallow weak layer, in order to verify the physical basis for assuming a long rise time and a reduced high frequency pulse for the slip on the shallow part of faults. It appears a 2-kilometer deep, weak zone along strike-slip faults could indeed reduce the high frequency energy radiated from shallow slip, and that this effect can best be represented by superimposing a small amplitude, short rise-time pulse at the onset of a much longer rise-time slip. A weak zone was modeled by inserting weak plastic layers of a few inches in thickness into the foam rubber model. For the 15 cm weak zone the average

  9. A nonlinear least-squares inverse analysis of strike-slip faulting with application to the San Andreas fault

    Science.gov (United States)

    Williams, Charles A.; Richardson, Randall M.

    1988-01-01

    A nonlinear weighted least-squares analysis was performed for a synthetic elastic layer over a viscoelastic half-space model of strike-slip faulting. Also, an inversion of strain rate data was attempted for the locked portions of the San Andreas fault in California. Based on an eigenvector analysis of synthetic data, it is found that the only parameter which can be resolved is the average shear modulus of the elastic layer and viscoelastic half-space. The other parameters were obtained by performing a suite of inversions for the fault. The inversions on data from the northern San Andreas resulted in predicted parameter ranges similar to those produced by inversions on data from the whole fault.

  10. Stress near geometrically complex strike-slip faults - Application to the San Andreas fault at Cajon Pass, southern California

    Science.gov (United States)

    Saucier, Francois; Humphreys, Eugene; Weldon, Ray, II

    1992-01-01

    A model is presented to rationalize the state of stress near a geometrically complex major strike-slip fault. Slip on such a fault creates residual stresses that, with the occurrence of several slip events, can dominate the stress field near the fault. The model is applied to the San Andreas fault near Cajon Pass. The results are consistent with the geological features, seismicity, the existence of left-lateral stress on the Cleghorn fault, and the in situ stress orientation in the scientific well, found to be sinistral when resolved on a plane parallel to the San Andreas fault. It is suggested that the creation of residual stresses caused by slip on a wiggle San Andreas fault is the dominating process there.

  11. Analogue Modeling of Oblique Convergent Strike-Slip Faulting and Application to The Seram Island, Eastern Indonesia

    Directory of Open Access Journals (Sweden)

    Benyamin Sapiie

    2014-12-01

    Full Text Available DOI:10.17014/ijog.v1i3.189Sandbox experiment is one of the types of analogue modeling in geological sciences in which the main purpose is simulating deformation style and structural evolution of the sedimentary basin.  Sandbox modeling is one of the effective ways in conducting physically modeling and evaluates complex deformation of sedimentary rocks. The main purpose of this paper is to evaluate structural geometry and deformation history of oblique convergent deformation using of integrated technique of analogue sandbox modeling applying to deformation of Seram Fold-Thrust-Belt (SFTB in the Seram Island, Eastern Indonesia. Oblique convergent strike-slip deformation has notoriously generated area with structural complex geometry and pattern resulted from role of various local parameters that control stress distributions. Therefore, a special technique is needed for understanding and solving such problem in particular to relate 3D fault geometry and its evolution. The result of four case (Case 1 to 4 modeling setting indicated that two of modeling variables clearly affected in our sandbox modeling results; these are lithological variation (mainly stratigraphy of Seram Island and pre-existing basement fault geometry (basement configuration. Lithological variation was mainly affected in the total number of faults development.  On the other hand, pre-existing basement fault geometry was highly influenced in the end results particularly fault style and pattern as demonstrated in Case 4 modeling.  In addition, this study concluded that deformation in the Seram Island is clearly best described using oblique convergent strike-slip (transpression stress system.

  12. The geometry of the active strike-slip El Tigre Fault, Precordillera of San Juan, Central-Western Argentina: integrating resistivity surveys with structural and geomorphological data

    Science.gov (United States)

    Fazzito, Sabrina Y.; Cortés, José M.; Rapalini, Augusto E.; Terrizzano, Carla M.

    2013-07-01

    The geometry and related geomorphological features of the right-lateral strike-slip El Tigre Fault, one of the main morphostructural discontinuities in the Central-Western Precordillera of Argentina, were investigated. Achievements of this survey include: recognition of structural and geometrical discontinuities along the fault trace, identification and classification of landforms associated with local transpressional and transtensional sectors, observation of significant changes in the fault strike and detection of right and left bends of different wavelength. In the Central Segment of the El Tigre Fault, 2D electrical resistivity tomography surveys were carried out across the fault zone. The resistivity imaging permitted to infer the orientation of the main fault surface, the presence of blind fault branches along the fault zone, tectonic tilting of the Quaternary sedimentary cover, subsurface structure of pressure ridges and depth to the water table. Based on this information, it is possible to characterize the El Tigre Fault also as an important hydro-geological barrier. Our survey shows that the main fault surface changes along different segments from a high-angle to a subvertical setting whilst the vertical-slip component is either reverse or normal, depending on the local transpressive or transtensive regime induced by major bends along the trace. These local variations are expressed as sections of a few kilometres in length with relatively homogeneous behaviour and frequently separated by oblique or transversal structures.

  13. Slip rate and slip magnitudes of past earthquakes along the Bogd left-lateral strike-slip fault (Mongolia)

    Science.gov (United States)

    Prentice, Carol S.; Rizza, M.; Ritz, J.F.; Baucher, R.; Vassallo, R.; Mahan, S.

    2011-01-01

    We carried out morphotectonic studies along the left-lateral strike-slip Bogd Fault, the principal structure involved in the Gobi-Altay earthquake of 1957 December 4 (published magnitudes range from 7.8 to 8.3). The Bogd Fault is 260 km long and can be subdivided into five main geometric segments, based on variation in strike direction. West to East these segments are, respectively: the West Ih Bogd (WIB), The North Ih Bogd (NIB), the West Ih Bogd (WIB), the West Baga Bogd (WBB) and the East Baga Bogd (EBB) segments. Morphological analysis of offset streams, ridges and alluvial fans—particularly well preserved in the arid environment of the Gobi region—allows evaluation of late Quaternary slip rates along the different faults segments. In this paper, we measure slip rates over the past 200 ka at four sites distributed across the three western segments of the Bogd Fault. Our results show that the left-lateral slip rate is∼1 mm yr–1 along the WIB and EIB segments and∼0.5 mm yr–1 along the NIB segment. These variations are consistent with the restraining bend geometry of the Bogd Fault. Our study also provides additional estimates of the horizontal offset associated with the 1957 earthquake along the western part of the Bogd rupture, complementing previously published studies. We show that the mean horizontal offset associated with the 1957 earthquake decreases progressively from 5.2 m in the west to 2.0 m in the east, reflecting the progressive change of kinematic style from pure left-lateral strike-slip faulting to left-lateral-reverse faulting. Along the three western segments, we measure cumulative displacements that are multiples of the 1957 coseismic offset, which may be consistent with a characteristic slip. Moreover, using these data, we re-estimate the moment magnitude of the Gobi-Altay earthquake at Mw 7.78–7.95. Combining our slip rate estimates and the slip distribution per event we also determined a mean recurrence interval of∼2500

  14. Structural evidence for strike-slip deformation in the Izmir-Balikesir transfer zone and consequences for late Cenozoic evolution of western Anatolia (Turkey)

    NARCIS (Netherlands)

    Uzel, B.; Sözbilir, H.; Özkaymak, T.; Kaymakci, N.; Langereis, C.G.

    2013-01-01

    The Izmir-Balikesir transfer zone (IBTZ) is a recently recognized strike-slip dominated shear zone that accommodates the differential deformation between the Cycladic and Menderes core complexes within the Aegean Extensional System. Here, we present new structural and kinematic data obtained from

  15. A Physical Analog Model of Strike-Slip Faulting for Model-Based Inquiry in the Classroom

    Science.gov (United States)

    Curren, I. S.; Glesener, G.

    2013-12-01

    Geoscience educators often use qualitative physical analog models to demonstrate natural processes; while these are effective teaching tools, they often neglect the fundamental scientific practices that make up the core of scientific work. Physical analog models with dynamic properties that can be manipulated and measured quantitatively in real-time, on the other hand, can give students the opportunity to explore, observe and empirically test their own ideas and hypotheses about the relevant target concepts within a classroom setting. Providing classroom content for inquiry, such as a hands-on physical analog model, which fosters students' production and refinement of their mental models in participatory and discursive activities have been argued by many education researchers to help students build a deeper understanding of science and scientific reasoning. We present a physical analog model that was originally developed by UCLA's Modeling and Educational Demonstrations Laboratory (MEDL) for the purpose of engaging students in the study of elastic rebound on a strike-slip fault; it was later modified to accommodate research of complex tectonic processes associated with strike-slip faulting, which are currently debated by scientists in both the geology and geophysics disciplines. During experimentation, it became clear that this new design could be used as a relevant resource for inquiry from which students would be able to make and discuss real-time empirical measurements and observations to help them infer causal accounts of theoretical and/or unobservable dynamic processes within the Earth's crust. In our poster session, we will: 1) demonstrate the physical analog model; 2) describe various real-time data collection tools, as well as quantitative methods students can use to process their data; and 3) describe the surficial, structural and relational similarities between the physical analog model and the target concepts intended for students to explore in the

  16. Modeling the evolution of the lower crust with laboratory derived rheological laws under an intraplate strike slip fault

    Science.gov (United States)

    Zhang, X.; Sagiya, T.

    2015-12-01

    The earth's crust can be divided into the brittle upper crust and the ductile lower crust based on the deformation mechanism. Observations shows heterogeneities in the lower crust are associated with fault zones. One of the candidate mechanisms of strain concentration is shear heating in the lower crust, which is considered by theoretical studies for interplate faults [e.g. Thatcher & England 1998, Takeuchi & Fialko 2012]. On the other hand, almost no studies has been done for intraplate faults, which are generally much immature than interplate faults and characterized by their finite lengths and slow displacement rates. To understand the structural characteristics in the lower crust and its temporal evolution in a geological time scale, we conduct a 2-D numerical experiment on the intraplate strike slip fault. The lower crust is modeled as a 20km thick viscous layer overlain by rigid upper crust that has a steady relative motion across a vertical strike slip fault. Strain rate in the lower crust is assumed to be a sum of dislocation creep and diffusion creep components, each of which flows the experimental flow laws. The geothermal gradient is assumed to be 25K/km. We have tested different total velocity on the model. For intraplate fault, the total velocity is less than 1mm/yr, and for comparison, we use 30mm/yr for interplate faults. Results show that at a low slip rate condition, dislocation creep dominates in the shear zone near the intraplate fault's deeper extension while diffusion creep dominates outside the shear zone. This result is different from the case of interplate faults, where dislocation creep dominates the whole region. Because of the power law effect of dislocation creep, the effective viscosity in the shear zone under intraplate faults is much higher than that under the interplate fault, therefore, shear zone under intraplate faults will have a much higher viscosity and lower shear stress than the intraplate fault. Viscosity contract between

  17. Inelastic off-fault response and three-dimensional dynamics of earthquake rupture on a strike-slip fault

    Science.gov (United States)

    Andrews, D.J.; Ma, Shuo

    2010-01-01

    Large dynamic stress off the fault incurs an inelastic response and energy loss, which contributes to the fracture energy, limiting the rupture and slip velocity. Using an explicit finite element method, we model three-dimensional dynamic ruptures on a vertical strike-slip fault in a homogeneous half-space. The material is subjected to a pressure-dependent Drucker-Prager yield criterion. Initial stresses in the medium increase linearly with depth. Our simulations show that the inelastic response is confined narrowly to the fault at depth. There the inelastic strain is induced by large dynamic stresses associated with the rupture front that overcome the effect of the high confining pressure. The inelastic zone increases in size as it nears the surface. For material with low cohesion (~5 MPa) the inelastic zone broadens dramatically near the surface, forming a "flowerlike" structure. The near-surface inelastic strain occurs in both the extensional and the compressional regimes of the fault, induced by seismic waves ahead of the rupture front under a low confining pressure. When cohesion is large (~10 MPa), the inelastic strain is significantly reduced near the surface and confined mostly to depth. Cohesion, however, affects the inelastic zone at depth less significantly. The induced shear microcracks show diverse orientations near the surface, owing to the low confining pressure, but exhibit mostly horizontal slip at depth. The inferred rupture-induced anisotropy at depth has the fast wave direction along the direction of the maximum compressive stress.

  18. The Iceland Plate Boundary Zone: Propagating Rifts, Migrating Transforms, and Rift-Parallel Strike-Slip Faults

    Science.gov (United States)

    Karson, J. A.

    2017-11-01

    Unlike most of the Mid-Atlantic Ridge, the North America/Eurasia plate boundary in Iceland lies above sea level where magmatic and tectonic processes can be directly investigated in subaerial exposures. Accordingly, geologic processes in Iceland have long been recognized as possible analogs for seafloor spreading in the submerged parts of the mid-ocean ridge system. Combining existing and new data from across Iceland provides an integrated view of this active, mostly subaerial plate boundary. The broad Iceland plate boundary zone includes segmented rift zones linked by transform fault zones. Rift propagation and transform fault migration away from the Iceland hotspot rearrange the plate boundary configuration resulting in widespread deformation of older crust and reactivation of spreading-related structures. Rift propagation results in block rotations that are accommodated by widespread, rift-parallel, strike-slip faulting. The geometry and kinematics of faulting in Iceland may have implications for spreading processes elsewhere on the mid-ocean ridge system where rift propagation and transform migration occur.

  19. Strike-slip fault Kinematics and mechanics at the seismic cycle time-scale : Results from new analogue model experiments.

    Science.gov (United States)

    Caniven, Yannick; Dominguez, Stéphane; Soliva, Roger; Cattin, Rodolphe; Peyret, Michel; Chéry, Jean; Romano, Christian

    2013-04-01

    The average seismic cycle duration extends from hundred to a few thousands years but geodetic measurements, including trilateration, GPS, Insar and seismological data extend over less than one century. This short time observation scale renders difficult, then, to constrain the role of key parameters such as fault friction and geometry, crust rheology, stress and strain rate that control the kinematics and mechanics of active faults. To solve this time scale issue, we have developed a new experimental set-up that reproduces scaled micro-earthquakes and several hundreds of seismic cycles along a strike-slip fault. The model is constituted by two polyurethane foam plates laterally in contact, lying on a basal silicone layer, which simulate the mechanical behaviour of an elastoplastic upper crust over a ductile lower crust, respectively. To simulate the boundary conditions of a strike-slip fault, a computerized motoreductor system moves the two compartments on an opposite sens and at a constant very low velocity (a few µm/s). The model spatial and temporal scaling, deduces from analog material physical and mechanical parameters, implies that 1 cm in the model represents 2-3 km in the nature and 1 s is equivalent to 5-15 years. Surface-horizontal strain field is quantified by sub-pixel correlation of digital camera pictures recorded every 16 µm of displacement. For each experience about 2000 horizontal-velocity field measurements are recorded. The analysis of model-interseismic and coseismic surface displacements and their comparison to seismogenic natural faults demonstrate that our analog model reproduces correctly both near and far-field surface strains. To compare the experiences, we have developed several algorithms that allow studying the main spatial and temporal evolution of the physical parameters and surface deformation processes that characterise the seismic cycle (magnitudes, stress, strain, friction coefficients, interseismic locking depth, recurrence

  20. Dynamic response to strike-slip tectonic control on the deposition and evolution of the Baranof Fan, Gulf of Alaska

    Science.gov (United States)

    Walton, Maureen A. L.; Gulick, Sean P. S.; Reece, Robert S.; Barth, Ginger A.; Christeson, Gail L.; VanAvendonk, Harm J.

    2014-01-01

    The Baranof Fan is one of three large deep-sea fans in the Gulf of Alaska, and is a key component in understanding large-scale erosion and sedimentation patterns for southeast Alaska and western Canada. We integrate new and existing seismic reflection profiles to provide new constraints on the Baranof Fan area, geometry, volume, and channel development. We estimate the fan’s area and total sediment volume to be ∼323,000 km2 and ∼301,000 km3, respectively, making it among the largest deep-sea fans in the world. We show that the Baranof Fan consists of channel-levee deposits from at least three distinct aggradational channel systems: the currently active Horizon and Mukluk channels, and the waning system we call the Baranof channel. The oldest sedimentary deposits are in the northern fan, and the youngest deposits at the fan’s southern extent; in addition, the channels seem to avulse southward consistently through time. We suggest that Baranof Fan sediment is sourced from the Coast Mountains in southeastern Alaska, transported offshore most recently via fjord to glacial sea valley conduits. Because of the translation of the Pacific plate northwest past sediment sources on the North American plate along the Queen Charlotte strike-slip fault, we suggest that new channel formation, channel beheadings, and southward-migrating channel avulsions have been influenced by regional tectonics. Using a simplified tectonic reconstruction assuming a constant Pacific plate motion of 4.4 cm/yr, we estimate that Baranof Fan deposition initiated ca. 7 Ma.

  1. (Plio-)Pleistocene alluvial-lacustrine basin infill evolution in a strike-slip active zone (Northern Andes, Western-Central Cordilleras, Colombia)

    OpenAIRE

    SUTER, F.; NEUWERTH, R.; GORIN, G.; GUZMÁN, C.

    2009-01-01

    The (Plio)-Pleistocene Zarzal Formation was deposited in the Cauca Depression and Quindío-Risaralda Basin between the Western and Central Cordilleras (Northern Andes). This area is structurally located on the transcurrent Romeral Fault System (RFS). Because of the interaction between the Nazca plate and the Chocó-Panamá block (an active indenter), the RFS strike-slip component changes direction around the study zone (dextral in the south, senestral in the north). Zarzal sediments are the olde...

  2. Ductile shear zones beneath strike-slip faults: Implications for the thermomechanics of the San Andreas fault zone

    Science.gov (United States)

    Thatcher, W.; England, P.C.

    1998-01-01

    We have carried out two-dimensional (2-D) numerical experiments on the bulk flow of a layer of fluid that is driven in a strike-slip sense by constant velocities applied at its boundaries. The fluid has the (linearized) conventional rheology assumed to apply to lower crust/upper mantle rocks. The temperature dependence of the effective viscosity of the fluid and the shear heating that accompanies deformation have been incorporated into the calculations, as has thermal conduction in an overlying crustal layer. Two end-member boundary conditions have been considered, corresponding to a strong upper crust driving a weaker ductile substrate and a strong ductile layer driving a passive, weak crust. In many cases of practical interest, shear heating is concentrated close to the axial plane of the shear zone for either boundary condition. For these cases, the resulting steady state temperature field is well approximated by a cylindrical heat source embedded in a conductive half-space at a depth corresponding to the top of the fluid layer. This approximation, along with the application of a theoretical result for one-dimensional shear zones, permits us to obtain simple analytical approximations to the thermal effects of 2-D ductile shear zones for a range of assumed rheologies and crustal geotherms, making complex numerical calculations unnecessary. Results are compared with observable effects on heat flux near the San Andreas fault using constraints on the slip distribution across the entire fault system. Ductile shearing in the lower crust or upper mantle can explain the observed increase in surface heat flux southeast of the Mendocino triple junction and match the amplitude of the regional heat flux anomaly in the California Coast Ranges. Because ductile dissipation depends only weakly on slip rate, faults moving only a few millimeters per year can be important heat sources, and the superposition of effects of localized ductile shearing on both currently active and now

  3. Influence of fault trend, fault bends, and fault convergence on shallow structure, geomorphology, and hazards, Hosgri strike-slip fault, offshore central California

    Science.gov (United States)

    Johnson, S. Y.; Watt, J. T.; Hartwell, S. R.

    2012-12-01

    We mapped a ~94-km-long portion of the right-lateral Hosgri Fault Zone from Point Sal to Piedras Blancas in offshore central California using high-resolution seismic reflection profiles, marine magnetic data, and multibeam bathymetry. The database includes 121 seismic profiles across the fault zone and is perhaps the most comprehensive reported survey of the shallow structure of an active strike-slip fault. These data document the location, length, and near-surface continuity of multiple fault strands, highlight fault-zone heterogeneity, and demonstrate the importance of fault trend, fault bends, and fault convergences in the development of shallow structure and tectonic geomorphology. The Hosgri Fault Zone is continuous through the study area passing through a broad arc in which fault trend changes from about 338° to 328° from south to north. The southern ~40 km of the fault zone in this area is more extensional, resulting in accommodation space that is filled by deltaic sediments of the Santa Maria River. The central ~24 km of the fault zone is characterized by oblique convergence of the Hosgri Fault Zone with the more northwest-trending Los Osos and Shoreline Faults. Convergence between these faults has resulted in the formation of local restraining and releasing fault bends, transpressive uplifts, and transtensional basins of varying size and morphology. We present a hypothesis that links development of a paired fault bend to indenting and bulging of the Hosgri Fault by a strong crustal block translated to the northwest along the Shoreline Fault. Two diverging Hosgri Fault strands bounding a central uplifted block characterize the northern ~30 km of the Hosgri Fault in this area. The eastern Hosgri strand passes through releasing and restraining bends; the releasing bend is the primary control on development of an elongate, asymmetric, "Lazy Z" sedimentary basin. The western strand of the Hosgri Fault Zone passes through a significant restraining bend and

  4. A recent Mw 4.3 earthquake proving activity of a shallow strike-slip fault in the northern part of the Western Desert, Egypt

    Science.gov (United States)

    Ezzelarab, Mohamed; Ebraheem, Mohamed O.; Zahradník, Jiří

    2018-03-01

    The Mw 4.3 earthquake of September 2015 is the first felt earthquake since 1900 A.D in the northern part of the Western Desert, Egypt, south of the El-Alamein City. The available waveform data observed at epicentral distances 52-391 km was collected and carefully evaluated. Nine broad-band stations were selected to invert full waveforms for the centroid position (horizontal and vertical) and for the focal mechanism solution. The first-arrival travel times, polarities and low-frequency full waveforms (0.03-0.08 Hz) are consistently explained in this paper as caused by a shallow source of the strike-slip mechanism. This finding indicates causal relation of this earthquake to the W-E trending South El-Alamein fault, which developed in Late Cretaceous as dextral strike slip fault. Recent activity of this fault, proven by the studied rare earthquake, is of fundamental importance for future seismic hazard evaluations, underlined by proximity (∼65 km) of the source zone to the first nuclear power plant planned site in Egypt. Safe exploration and possible future exploitation of hydrocarbon reserves, reported around El-Alamein fault in the last decade, cannot be made without considering the seismic potential of this fault.

  5. Mechanics of evenly spaced strike-slip faults and its implications for the formation of tiger-stripe fractures on Saturn's moon Enceladus

    Science.gov (United States)

    Yin, An; Zuza, Andrew V.; Pappalardo, Robert T.

    2016-03-01

    We present the first mechanical analysis based on realistic rheology and boundary conditions on the formation of evenly spaced strike-slip faults. Two quantitative models employing the stress-shadow concept, widely used for explaining extensional-joint spacing, are proposed in this study: (1) an empirically based stress-rise-function model that simulates the brittle-deformation process during the formation of evenly spaced parallel strike-slip faults, and (2) an elastic plate model that relates fault spacing to the thickness of the fault-hosting elastic medium. When applying the models for the initiation and development of the tiger-stripe fractures (TSF) in the South Polar Terrain (SPT) of Enceladus, the mutually consistent solutions of the two models, as constrained by the mean spacing of the TSF at ∼35 km, requires that the brittle ice-shell thickness be ∼30 km, the elastic thickness be ∼0.7 km, and the cohesive strength of the SPT ice shell be ∼30 kPa. However, if the brittle and elastic models are decoupled and if the ice-shell cohesive strength is on the order of ∼1 MPa, the brittle ice shell would be on the order of ∼10 km.

  6. The 2015 M7.2 Sarez, Central Pamir, Earthquake And The Importance Of Strike-Slip Faulting In The Pamir Interior: Insights From Geodesy And Field Observations

    Science.gov (United States)

    Metzger, Sabrina; Schurr, Bernd; Ratschbacher, Lothar; Schöne, Tilo; Kufner, Sofia-Katerina; Zhang, Yong; Sudhaus, Henriette

    2017-04-01

    The Pamir mountain range, located in the Northwest of the India-Asia collision zone, accommodates approximately one third of the northward advance of the Indian continent at this longitude (i. e. ˜34 mm/yr) mostly by shortening at its northern thrust system. Geodetic and seismic data sets reveal here a narrow zone of high deformation and M7+ earthquakes of mostly thrust type with some dextral strike-slip faulting observed, too. The Pamir interior shows sinistral strike-slip and normal faulting indicating north-south compression and east-west extension. In this tectonic setting the two largest instrumentally recorded earthquakes, the M7+ 1911 and 2015 earthquake events in the central Pamir occurred with left-lateral shear along a NE-SW rupture plane. We present the co-seismic deformation field of the 2015 earthquake observed by radar satellite interferometry (InSAR), SAR amplitude pixel offsets and high-rate Global Positioning System (GPS). The InSAR and pixel offset results suggest a 50+ km long rupture with sinistral fault offsets at the surface of more than 2 m on a yet unmapped fault trace of the Sarez Karakul Fault System (SKFS). A distributed slip model with a data-driven slip patch resolution yields a sub-vertical fault plane with a strike of N39.5 degrees and a rupture area of ˜80 x 40 km with a maximum slip of 2 m in the upper 10 km of the crust near the surface rupture. Field observations collected some nine months after the earthquake confirm the rupture mechanism, surface trace location and fault offset measurements as constrained by geodetic data. Diffuse deformation was observed across a 1-2 km wide zone, hosting primary fractures sub-parallel to the rupture strike with offsets of 2 m and secondary, en echelon fractures including Riedel shears and hybrid fractures often related to gravitational mass movements. The 1911 and 2015 earthquakes demonstrate the importance of sinistral strike-slip faulting on the SKFS, contributing both to shear between the

  7. States of stress and slip partitioning in a continental scale strike-slip duplex: Tectonic and magmatic implications by means of finite element modeling

    Science.gov (United States)

    Iturrieta, Pablo Cristián; Hurtado, Daniel E.; Cembrano, José; Stanton-Yonge, Ashley

    2017-09-01

    Orogenic belts at oblique convergent subduction margins accommodate deformation in several trench-parallel domains, one of which is the magmatic arc, commonly regarded as taking up the margin-parallel, strike-slip component. However, the stress state and kinematics of volcanic arcs is more complex than usually recognized, involving first- and second-order faults with distinctive slip senses and mutual interaction. These are usually organized into regional scale strike-slip duplexes, associated with both long-term and short-term heterogeneous deformation and magmatic activity. This is the case of the 1100 km-long Liquiñe-Ofqui Fault System in the Southern Andes, made up of two overlapping margin-parallel master faults joined by several NE-striking second-order faults. We present a finite element model addressing the nature and spatial distribution of stress across and along the volcanic arc in the Southern Andes to understand slip partitioning and the connection between tectonics and magmatism, particularly during the interseismic phase of the subduction earthquake cycle. We correlate the dynamics of the strike-slip duplex with geological, seismic and magma transport evidence documented by previous work, showing consistency between the model and the inferred fault system behavior. Our results show that maximum principal stress orientations are heterogeneously distributed within the continental margin, ranging from 15° to 25° counter-clockwise (with respect to the convergence vector) in the master faults and 10-19° clockwise in the forearc and backarc domains. We calculate the stress tensor ellipticity, indicating simple shearing in the eastern master fault and transpressional stress in the western master fault. Subsidiary faults undergo transtensional-to-extensional stress states. The eastern master fault displays slip rates of 5 to 10 mm/yr, whereas the western and subsidiary faults show slips rates of 1 to 5 mm/yr. Our results endorse that favorably oriented

  8. Rupture model of the 2015 M7.2 Sarez, Central Pamir, earthquake and the importance of strike-slip faulting in the Pamir interior

    Science.gov (United States)

    Metzger, S.; Schurr, B.; Schoene, T.; Zhang, Y.; Sudhaus, H.

    2016-12-01

    The Pamir mountain range, located in the Northwest of the India-Asia collision zone, accommodates approximately one third of the northward advance of the Indian continent at this longitude (i.e. 34 mm/yr) mostly by shortening at its northern thrust system. Geodetic and seismic data sets reveal here a narrow zone of high deformation and M7+ earthquakes of mostly thrust type with some dextral strike-slip faulting observed, too. The Pamir interior shows sinistral strike-slip and normal faulting indicating north-south compression and east-west extension. In this tectonic setting the two largest instrumentally recorded earthquakes, the M7+ 1911 and 2015 earthquake events in the central Pamir occurred with left-lateral shear along a NE-SW rupture plane. We present the co-seismic deformation field of the 2015 earthquake observed by Radar satellite interferometry (InSAR), SAR amplitude offsets and high-rate Global Positioning System (GPS). The InSAR and offset results reveal that the earthquake created a 50 km long surface rupture with maximum left-lateral offsets of more than two meters on a yet unmapped fault trace of the Sarez Karakul Fault System (SKFS). We further derive a distributed slip-model including a thorough model parameter uncertainty study. Using a two-step approach to first find the optimal rupture geometry and then invert for slip on discrete patches, we show that a data-driven patch resolution produces yields a better representation of the near-surface slip and an increased slip precision than a uniform patch approach without increasing the number of parameters and thus calculation time. Our best-fit model yields a sub-vertical fault plane with a strike of N39.5 degrees and a rupture area of 80 x 40 km2 with a maximum slip of 2 meters in the upper 10 km of the crust near the surface rupture. The 1911 and 2015 earthquakes demonstrate the importance of sinistral strike-slip faulting on the SKFS, contributing both to shear between the western and eastern

  9. Role of the offshore Pedro Banks left-lateral strike-slip fault zone in the plate tectonic evolution of the northern Caribbean

    Science.gov (United States)

    Ott, B.; Mann, P.; Saunders, M.

    2013-12-01

    Previous workers, mainly mapping onland active faults on Caribbean islands, defined the northern Caribbean plate boundary zone as a 200-km-wide bounded by two active and parallel strike-slip faults: the Oriente fault along the northern edge of the Cayman trough with a GPS rate of 14 mm/yr, and and the Enriquillo-Plaintain Garden fault zone (EPGFZ) with a rate of 5-7 mm/yr. In this study we use 5,000 km of industry and academic data from the Nicaraguan Rise south and southwest of the EPGFZ in the maritime areas of Jamaica, Honduras, and Colombia to define an offshore, 700-km-long, active, left-lateral strike-slip fault in what has previously been considered the stable interior of the Caribbean plate as determined from plate-wide GPS studies. The fault was named by previous workers as the Pedro Banks fault zone because a 100-km-long segment of the fault forms an escarpment along the Pedro carbonate bank of the Nicaraguan Rise. Two fault segments of the PBFZ are defined: the 400-km-long eastern segment that exhibits large negative flower structures 10-50 km in width, with faults segments rupturing the sea floor as defined by high resolution 2D seismic data, and a 300-km-long western segment that is defined by a narrow zone of anomalous seismicity first observed by previous workers. The western end of the PBFZ terminates on a Quaternary rift structure, the San Andres rift, associated with Plio-Pleistocene volcanism and thickening trends indicating initial rifting in the Late Miocene. The southern end of the San Andreas rift terminates on the western Hess fault which also exhibits active strands consistent with left-lateral, strike-slip faults. The total length of the PBFZ-San Andres rift-Southern Hess escarpment fault is 1,200 km and traverses the entire western end of the Caribbean plate. Our interpretation is similar to previous models that have proposed the "stable" western Caribbean plate is broken by this fault whose rate of displacement is less than the threshold

  10. The last interglacial period at Guantanamo Bay, Cuba and an estimate of late Quaternary tectonic uplift rate in a strike-slip regime

    Science.gov (United States)

    Schweig, E. S.; Muhs, D. R.; Simmons, K. R.; Halley, R. B.

    2015-12-01

    Guantanamo Bay, Cuba is an area dominated by a strike-slip tectonic regime and is therefore expected to have very low Quaternary uplift rates. We tested this hypothesis by study of an unusually well preserved emergent reef terrace around the bay. Up to 12 m of unaltered, growth-position reef corals are exposed at about 40 sections examined around ˜40 km of coastline. Maximum reef elevations in the protected, inner part of the bay are ˜11-12 m, whereas outer-coast shoreline angles of wave-cut benches are as high as ˜14 m. Fifty uranium-series analyses of unrecrystallized corals from six localities yield ages ranging from ˜134 ka to ˜115 ka, when adjusted for small biases due to slightly elevated initial 234U/238U values. Thus, ages of corals correlate this reef to the peak of the last interglacial period, marine isotope stage (MIS) 5.5. Previously, we dated the Key Largo Limestone to the same high-sea stand in the tectonically stable Florida Keys. Estimates of paleo-sea level during MIS 5.5 in the Florida Keys are ~6.6 to 8.3 m above present. Assuming a similar paleo-sea level in Cuba, this yields a long-term tectonic uplift rate of 0.04-0.06 m/ka over the past ~120 ka. This estimate supports the hypothesis that the tectonic uplift rate should be low in this strike-slip regime. Nevertheless, on the southeast coast of Cuba, east of our study area, we have observed flights of multiple marine terraces, suggesting either (1) a higher uplift rate or (2) an unusually well-preserved record of pre-MIS 5.5 terraces not observed at Guantanamo Bay.

  11. The 2015 Mw7.2 Sarez Strike-Slip Earthquake in the Pamir Interior: Response to the Underthrusting of India's Western Promontory

    Science.gov (United States)

    Metzger, Sabrina; Schurr, Bernd; Ratschbacher, Lothar; Sudhaus, Henriette; Kufner, Sofia-Katerina; Schöne, Tilo; Zhang, Yong; Perry, Mason; Bendick, Rebecca

    2017-11-01

    The Pamir orogen, Central Asia, is the result of the ongoing northward advance of the Indian continent causing shortening inside Asia. Geodetic and seismic data place the most intense deformation along the northern rim of the Pamir, but the recent 7 December 2015, Mw7.2 Sarez earthquake occurred in the Pamir's interior. We present a distributed slip model of this earthquake using coseismic geodetic data and postseismic field observations. The earthquake ruptured an ˜80 km long, subvertical, sinistral fault consisting of three right-stepping segments from the surface to ˜30 km depth with a maximum slip of three meters in the upper 10 km of the crust. The coseismic slip model agrees well with en échelon secondary surface breaks that are partly influenced by liquefaction-induced mass movements. These structures reveal up to 2 m of sinistral offset along the northern, low-offset segment of modeled rupture. The 2015 event initiated close to the presumed epicenter of the 1911 Mw˜7.3 Lake Sarez earthquake, which had a similar strike-slip mechanism. These earthquakes highlight the importance of NE trending sinistral faults in the active tectonics of the Pamir. Strike-slip deformation accommodates shear between the rapidly northward moving eastern Pamir and the Tajik basin in the west and is part of the westward (lateral) extrusion of thickened Pamir plateau crust into the Tajik basin. The Sarez-Karakul fault system and the two large Sarez earthquakes likely are crustal expressions of the underthrusting of the northwestern leading edge of the Indian mantle lithosphere beneath the Pamir.

  12. High-rate GPS results for the April 2012 Sumatra earthquake sequence, an unusual, complex, and very large intraplate strike-slip event

    Science.gov (United States)

    Hill, E. M.; Hermawan, I.; Lay, T.; Yue, H.; Banerjee, P.; Qiu, Q.; Macpherson, K. A.; Feng, L.; Tsang, L. L.; Lubis, A.; Tapponnier, P.; Sieh, K. E.

    2012-12-01

    The 11 April 2012 Mw 8.6 Sumatra earthquake was one of the largest strike-slip earthquakes ever recorded, and also one of the largest intraplate earthquakes. It was followed 2 hours later by another great earthquake, of Mw 8.2, in a similar location. The events occurred ~400 km from northern Sumatra, on the oceanic side of the Sunda megathrust. The event was recorded by high-rate GPS stations from our 50-station Sumatra GPS Array (SuGAr). We will present the coseismic displacements and constraints on slip obtained from this network. The location of the events is very interesting. Scientists have long been puzzled by the nature and location of the boundary between the Indian and Australian plates in the depths of the Indian Ocean. Because of the resistance provided by the collision of India with Tibet far to the north, the Indian plate is moving relatively northwards at about 1 cm/yr slower than the Australian plate; this difference in velocity causes strain between the Indian and Australian plates. These earthquakes provide important new evidence that this strain is reactivating a system of faults on the seafloor that were inherited from an older geological epoch, and bring up questions about why this deformation appears to be diffuse, rather than behaving as a proper plate boundary. The events also highlight a back-and-forth interaction between the intraplate faults and the Sunda megathrust; the 2004 megathrust event brought these earthquakes ahead in time, but these earthquakes will in turn have stressed the megathrust. Published seismological results have indicated great complexity in the rupture patterns for these events, with a cascading failure of multiple conjugate faults. Surprisingly, the majority of slip seems to have occurred on the WNW-trending, right-lateral faults, rather than the NNE-trending left-lateral faults that are prominent features of the seafloor. The seismological results also show that the ruptures are likely to have extended from the

  13. Palaeopermeability anisotropies of a strike-slip fault damage zone: 3D Insights of quantitative fluid flow from µCT analysis.

    Science.gov (United States)

    Gomila, R.; Arancibia, G.; Nehler, M.; Bracke, R.; Morata, D.

    2017-12-01

    Fault zones and their related structural permeability are a key aspect in the migration of fluids through the continental crust. Therefore, the estimation of the hydraulic properties (palaeopermeability conditions; k) and the spatial distribution of the fracture mesh within the damage zone (DZ) are critical in the assessment of fault zones behavior for fluids. The study of the real spatial distribution of the veinlets of the fracture mesh (3D), feasible with the use of µCT analyses, is a first order factor to unravel both, the real structural permeability conditions of a fault-zone, and the validation of previous (and classical) estimations made in 2D analyses in thin-sections. This work shows the results of a fault-related fracture mesh and its 3D spatial distribution in the damage-zone of the Jorgillo Fault (JF), an ancient subvertical left-lateral strike-slip fault exposed in the Atacama Fault System in northern Chile. The JF is a ca. 20 km long NNW-striking strike-slip fault with sinistral displacement of ca. 4 km. The methodology consisted of drilling 5 mm vertically oriented plugs at several locations within the JF damage zone. Each specimen was scanned with an X-Ray µCT scanner, to assess the fracture mesh, with a voxel resolution of ca. 4.5 µm in the 3D reconstructed data. Tensor permeability modeling, using Lattice-Boltzmann Method, through the segmented microfracture mesh show GMkmin (geometric mean values) of 2.1x10-12 and 9.8x10-13 m2, and GMkmax of 6.4x10-12 and 2.1x10-12 m2. A high degree of anisotropy of the DZ permeability tensor both sides of the JF (eastern and western side, respectively) is observed, where the k values in the kmax plane are 2.4 and 1.9 times higher than the kmin direction at the time of fracture sealing. This style of anisotropy is consistent with the obtained for bedded sandstones supporting the idea that damage zones have an analogous effect - but vertically orientated - on bulk permeability (in low porosity rocks) as

  14. Cenozoic structural inversion from transtension to transpression in Yingxiong Range, western Qaidam Basin: New insights into strike-slip superimposition controlled by Altyn Tagh and Eastern Kunlun Faults

    Science.gov (United States)

    Cheng, Xiang; Zhang, Daowei; Jolivet, Marc; Yu, Xiangjiang; Du, Wei; Liu, Runchao; Guo, Zhaojie

    2018-01-01

    A Cenozoic structural inversion event from transtension to transpression involving salt tectonics has been uncovered in the Yingxiong Range, the western Qaidam Basin. Seismic reflection data show that there are two common structural styles in the Yingxiong Range: (1) the positive flower structure; (2) the thrust-controlled fold at shallow depth and the positive inverted flower structure at deep levels, which are separated by a salt layer in the upper Xiaganchaigou Formation. The Yingxiong Range experienced a first stage of transtension in the Eocene, induced by the Altyn Tagh Fault, and a second stage of transpression from the early Miocene to present, jointly controlled by the Altyn Tagh and Eastern Kunlun Faults. The Eocene transtension produced numerous NW-striking right-stepping en-échelon transtensional normal faults or fractures in the Yingxiong Range. At the same time, evaporites and mudstone were deposited in the vicinity of these faults. In the early Miocene, the Eocene transtensional normal faults were reactivated in a reverse sense, and the thrust-controlled folds at shallow depth started to form simultaneously. With transpression enhanced in the late Cenozoic, positive flower structures directly formed in places without evaporites. The Cenozoic transtension to transpression inversion of the Yingxiong Range is the result of strike-slip superimposition controlled by the Altyn Tagh and Eastern Kunlun Faults in time and space.

  15. The tsunami-like sea level disturbance in Crotone harbor, Italy, after the Mw6.5 strike-slip earthquake of 17 November 2015 in Lefkada Isl., Ionian Sea, Greece

    Science.gov (United States)

    Novikova, Tatyana; Annunziato, Alessandro; Charalampakis, Marinos; Romano, Fabrizio; Volpe, Manuela; Tonini, Roberto; Gerardinger, Andrea; Papadopoulos, Gerassimos A.

    2016-04-01

    On 17 November 2015 an Mw6.5 earthquake ruptured offshore Lefkada Isl. in Ionian Sea, Greece, causing two human victims, minor damage and several ground failures including coastal landslides. Fault plane solutions released by CMT/Harvard, NOA and other institutes have indicated that the faulting style was strike-slip right-lateral, which is quite typical for the area, as for example, the Mw6.3 event that occurred on August 14, 2003, in exactly the same fault zone. In spite of the very low tsunami potential commonly associated to this faulting mechanism, a tsunami-like sea level change was recorded after the earthquake by one tide-gauge in the Crotone harbor, Italy. Preliminary tsunami numerical simulations were performed to reproduce the observed signal. The spectral analysis of the synthetic mareograms close to the entrance of the harbor shows the presence of some peaks that could justify the relation between the natural port resonance and the observed wave amplification. Of particular interest is the coupling between the tsunami energy and the natural modes of basin oscillation enhancing tsunami wave amplitude in harbors through resonance, as shown in some historical events in the Mediterranean Sea and elsewhere. This research is a contribution to the EU-FP7 tsunami research project ASTARTE (Assessment, Strategy And Risk Reduction for Tsunamis in Europe), grant agreement no: 603839, 2013-10-30.

  16. Investigation of intraplate seismicity near the sites of the 2012 major strike-slip earthquakes in the eastern Indian Ocean through a passive-source OBS experiment

    Science.gov (United States)

    Guo, L.; Lin, J.; Yang, H.

    2017-12-01

    The 11 April 2012 Mw8.6 earthquake off the coast of Sumatra in the eastern Indian Ocean was the largest strike-slip earthquake ever recorded. The 2012 mainshock and its aftershock sequences were associated with complex slip partitioning and earthquake interactions of an oblique convergent system, in a new plate boundary zone between the Indian and Australian plates. The detail processes of the earthquake interactions and correlation with seafloor geological structure, however, are still poorly known. During March-April 2017, an array of broadband OBS (ocean bottom seismometer) were deployed, for the first time, near the epicenter region of the 2012 earthquake sequence. During post-expedition data processing, we identified 70 global earthquakes from the National Earthquake Information Center (NEIC) catalog that occurred during our OBS deployment period. We then picked P and S waves in the seismic records and analyzed their arrival times. We further identified and analyzed multiple local earthquakes and examined their relationship to the observed seafloor structure (fracture zones, seafloor faults, etc.) and the state of stresses in this region of the eastern Indian Ocean. The ongoing analyses of the data obtained from this unique seismic experiment are expected to provide important constraints on the large-scale intraplate deformation in this part of the eastern Indian Ocean.

  17. Relationships between along-fault heterogeneous normal stress and fault slip patterns during the seismic cycle: Insights from a strike-slip fault laboratory model

    Science.gov (United States)

    Caniven, Yannick; Dominguez, Stéphane; Soliva, Roger; Peyret, Michel; Cattin, Rodolphe; Maerten, Frantz

    2017-12-01

    We use a strike-slip fault analog model to study experimentally the role played by along-fault non-uniform and asymmetric applied normal stress on both coseismic slip and long-term fault behavior. Our model is based on a visco-elasto-plastic multi-layered rheology that allows to produce several hundreds of scaled analog microquakes and associated seismic cycles. Uniform or heterogeneous applied normal stress along the fault plane is imposed and maintained constant during the whole experiment durations. Our results suggest that coseismic slip patterns are strongly controlled by spatial normal stress variations and subsequent accumulated shear stress along fault strike. Major microquakes occur preferentially in zones of major shear stress asperities. Coseismic slip distributions exhibit a pattern similar to the along-fault applied normal stress distribution. The occurrence of isolated low to moderate microquakes where residual stresses persist around secondary stress asperities, indicates that stress conditions along the fault also control the whole variability of fault slip events. Moreover, when fault slip stability conditions are modulated by normal stress distribution, our experiments suggest that the along-fault stress heterogeneity influences the seismic cycle regularity and, consequently, long-term fault slip behavior. Uniform applied normal stress favors irregular seismic cycles and the occurrence of earthquakes clustering, whereas non-uniform normal stress with a single high amplitude stress asperity generates strong characteristic microquake events with stable return periods. Together our results strengthen the assumption that coseismic slip distribution and earthquake variability along an active fault may provide relevant information on long term tectonic stress and could thus improve seismic hazard assessment.

  18. From 2012 HAITI-SIS Survey: thick-skin versus thin-skin tectonics partitioned along offshore strike-slip Faults-Haïti

    Science.gov (United States)

    Ellouz, N.; Leroy, S. D.; Momplaisir, R.; Mercier de Lepinay, B.

    2013-12-01

    The characterization of the deformation along large strike-slip fault-systems like transpressive boundaries between N. Caribbean/N America is a challenging topic, which requires a multi-scale approach. Thanks to Haiti-sis new data, the precise description of the fault segmentation pattern, the sedimentogical distribution, the uplift/subsidence rates, the along-fault and intra-basin fluids circulations, allows to actualize the evolution of the deformation history up to present-day . All the co-seismic surface to near-surface events, have to be also identified in order to integrate geophysical solutions for the earthquake, within the present-day geological and structural pattern. These two approaches, ranging from geological to instantaneous time-scales have been used during multi-tools Haiti-Sis oceanographic survey, allowing to document and image these different aspects at a large scale. The complex strike-slip North Caribbean boundary registered significative stress partitioning. Oblique convergence is expressed by along-strike evolution; from rifted segments (Cayman Through) to transpressive ones (Haiti, Dominican Rep.), to subduction (Porto Rico). In the Haiti-Sis survey, we acquired new offshore data surrounding the active fault areas, in the Gonâve Bay, the Jamaica Channel and along Southern Peninsula. Mapping the sea-floor, and HR seismic acquisition were our main objectives, in order to characterize the fault and fold architecture, with a new delineation of active segments. Offshore piston cores, have been used as representative of the modern basin sedimentation, and to document the catastrophic events (earthquakes, massive flood or sudden destabilization of the platform ) represented by turbiditic or mass-flow sequences, with the objective to track the time recurrence of seismic events by dating some of these catastrophic sediment deposition. At surface, the other markers of the fault activity are linked with along-fault permeability and fluid circulation

  19. Structure of the la VELA Offshore Basin, Western Venezuela: AN Obliquely-Opening Rift Basin Within the South America-Caribbean Strike-Slip Plate Boundary

    Science.gov (United States)

    Blanco, J. M.; Mann, P.

    2015-12-01

    Bathymetric, gravity and magnetic maps show that the east-west trend of the Cretaceous Great Arc of the Caribbean in the Leeward Antilles islands is transected by an en echelon series of obliquely-sheared rift basins that show right-lateral offsets ranging from 20 to 40 km. The basins are 75-100 km in length and 20-30 km in width and are composed of sub-parallel, oblique slip normal faults that define deep, bathymetric channels that bound the larger islands of the Leeward Antilles including Aruba, Curacao and Bonaire. A single basin of similar orientation and structure, the Urumaco basin, is present to the southwest in the Gulf of Venezuela. We mapped structures and sedimentation in the La Vela rift basin using a 3D seismic data volume recorded down to 6 seconds TWT. The basin can be mapped from the Falcon coast where it is correlative with the right-lateral Adicora fault mapped onshore, and its submarine extension. To the southeast of the 3D survey area, previous workers have mapped a 70-km-wide zone of northeast-striking, oblique, right-lateral faults, some with apparent right-lateral offsets of the coastline. On seismic data, the faults vary in dip from 45 to 60 degrees and exhibit maximum vertical offsets of 600 m. The La Vela and other obliquely-opening rifts accommodate right-lateral shear with linkages to intervening, east-west-striking right-lateral faults like the Adicora. The zone of oblique rifts is restricted to the trend of the Great Arc of the Caribbean and may reflect the susceptiblity of this granitic basement to active shearing. The age of onset for the basins known from previous studies on the Leeward Antilles is early Miocene. As most of these faults occur offshore their potential to generate damaging earthquakes in the densely populated Leeward Antilles is not known.

  20. Reconstructing the magnitude and timing of late Pleistocene and Holocene strike-slip events within the Marlborough Fault Zone, New Zealand

    Science.gov (United States)

    Rhodes, Ed; Dolan, James; Van Dissen, Russ; Langridge, Rob; Zinke, Rob; Hatem, Alex; McGuire, Chris; Brown, Nathan

    2017-04-01

    In most instances, information about the timing of pre-historic earthquake events comes from palaeoseismic trenches located within sediments that were deposited gradually and are close to the fault. Earthquake events are recognised by disturbed stratigraphy, and the timing provided by radiocarbon dating of organic materials that constrain the youngest disturbances for each event. In contrast, fault slip rates are typically derived from the dating of geomorphic features that are offset by one or more slip events. In this latter case, it is often hard to locate suitable organic material for dating these features which often comprise fluvial terraces or channels, and a variety of alternative chronological approaches has been taken including the use of terrestrial cosmogenic nuclides (TCNs; 10Be, 36Cl), U-series dating of carbonate overgrowths on pebbles, and/or luminescence dating of sediments. Using luminescence dating based on single grains of K-feldspar and a post-IR IRSL (Infra-Red Stimulated Luminescence) measurement protocol, we have been able to control the age of several offset terrace units from a number of major strike slip faults of the Marlborough Fault Zone, New Zealand. In the past, arguments concerning the selection of which geomorphic terrace feature to date have been presented, and typically a single age estimate, or small number of dates were used to constrain the derived slip rate. In the Marlborough region, we have sampled several locations characterised by multiple fluvial terraces dating from the late Glacial period (c. 16,000 years ago) through the Holocene. By using a high sampling density involving multiple age estimates within each terrace, dating each one of the terraces, and applying a Bayesian statistical approach to constrain the age of deposition and incision events, we are able to approach a situation where we can derive slip-per-event data and event timing from the same dataset. This can overcome problems of relating observed slip

  1. A Comparison of Geodetic and Geologic Rates Prior to Large Strike-Slip Earthquakes: A Diversity of Earthquake-Cycle Behaviors?

    Science.gov (United States)

    Dolan, James F.; Meade, Brendan J.

    2017-12-01

    Comparison of preevent geodetic and geologic rates in three large-magnitude (Mw = 7.6-7.9) strike-slip earthquakes reveals a wide range of behaviors. Specifically, geodetic rates of 26-28 mm/yr for the North Anatolian fault along the 1999 MW = 7.6 Izmit rupture are ˜40% faster than Holocene geologic rates. In contrast, geodetic rates of ˜6-8 mm/yr along the Denali fault prior to the 2002 MW = 7.9 Denali earthquake are only approximately half as fast as the latest Pleistocene-Holocene geologic rate of ˜12 mm/yr. In the third example where a sufficiently long pre-earthquake geodetic time series exists, the geodetic and geologic rates along the 2001 MW = 7.8 Kokoxili rupture on the Kunlun fault are approximately equal at ˜11 mm/yr. These results are not readily explicable with extant earthquake-cycle modeling, suggesting that they may instead be due to some combination of regional kinematic fault interactions, temporal variations in the strength of lithospheric-scale shear zones, and/or variations in local relative plate motion rate. Whatever the exact causes of these variable behaviors, these observations indicate that either the ratio of geodetic to geologic rates before an earthquake may not be diagnostic of the time to the next earthquake, as predicted by many rheologically based geodynamic models of earthquake-cycle behavior, or different behaviors characterize different fault systems in a manner that is not yet understood or predictable.

  2. Seismically-triggered soft-sediment deformation structures close to a major strike-slip fault system in the Eastern Alps (Hirlatz cave, Austria)

    Science.gov (United States)

    Salomon, Martina Lan; Grasemann, Bernhard; Plan, Lukas; Gier, Susanne; Schöpfer, Martin P. J.

    2018-05-01

    We investigate episodic soft-sediment deformation structures cross-cut by normal faults preserved in unlithified finely laminated calcite rich sediments in the Hirlatz cave in the Northern Calcareous Alps (Austria). These sediments comprise varve-like alternations of brighter carbonate/quartz rich layers, and darker clay mineral rich layers. The deformed sediments contain abundant millimeter to centimeter-scale soft-sediment structures (load casts, ball-and-pillow structures), sheet slumps (thrust faults and folds), erosive channels filled with slides and chaotic slumps. After deposition and soft-sediment deformation normal faults developed within the entire sedimentary succession, an event that probably correlates with an offset of c. 10 cm of the passage wall above the outcrop. Our major conclusions are: (i) The sediments have a glacial origin and were deposited in the Hirlatz cave under phreatic fluvio-lacustrine conditions. The deposition and the soft-sediment deformation occurred most likely during the last glaciation (i.e. around 25 ka ago); (ii) The liquefaction and formation of the soft-sediment structures in water-saturated stratified layers was triggered by episodic seismic events; (iii) The internally deformed sediments were later displaced by normal faults; (iv) A possible source for the seismic events is the active sinistral Salzach-Ennstal-Mariazeller-Puchberger (SEMP) strike-slip fault which is located about 10 km south of the outcrop and plays a major role in accommodating the extrusion of the Eastern Alps towards the Pannonian Basin. To our knowledge, the described structures are the first report of liquefaction and seismically induced soft-sediment deformations in Quaternary sediments in the Eastern Alps.

  3. 3D deformation in strike-slip systems: Analogue modelling and numerical restoration Deformación 3D en sistemas de rumbo: modelación analógica y restauración numérica

    Directory of Open Access Journals (Sweden)

    Daniel González

    2012-05-01

    Full Text Available Regional and local strike-slip systems in Chile are complex and pose interesting questions, such as the interaction between strike-slip and reverse faults, how they evolve, and the relationship between shortening, rotation and uplift. Within this context, we developed a new analytical method based on analogue and numerical modelling applied to 3D, pure and transtensional-transpressional strike-slip systems. Analogue modelling results indicate that in restraining stepovers of strike-slip fault systems, where antiformal pop-up structures are usually formed, pre-existent basement structures with a high angle to the main strike-slip fault will generate a higher rotation of blocks. However, when these structures are oriented at a high angle with respect to the main stress convergence vector, the rotation will be less and therefore a higher tendency to uplift will be produced. These results were applied to NW- and SE-striking basement faults oblique to N-S mega-thrust faults in central Chile (32°-35°S, for which we propose a simultaneous development based on the analogue model results. Moreover, we propose that strike-slip movement occurred on thrust faults in central Chile. Furthermore, we performed a numerical restoration of an analogue experiment which modeled a pure strike-slip system, and concluded that the restoration is very sensitive to shortening data as well as to rotational data. These results are extremely important for future numerical and regional analysis of strike-slip systems.Los sistemas de rumbo regionales y locales en Chile son complejos y plantean interesantes preguntas, tales como la interacción entre fallas de rumbo y fallas inversas, cómo evolucionan ellas, y la relación entre acortamiento, rotación y alzamiento. En este contexto, desarrollamos un nuevo método analítico basado en modelamiento analógico y numérico de sistemas de rumbo de cizalle puro y sistemas transpresionales-trantensionales en 3D. Los resultados del

  4. Constraints on the rheology of the lower crust in a strike-slip plate boundary: evidence from the San Quintín xenoliths, Baja California, Mexico

    Science.gov (United States)

    van der Werf, Thomas; Chatzaras, Vasileios; Marcel Kriegsman, Leo; Kronenberg, Andreas; Tikoff, Basil; Drury, Martyn R.

    2017-12-01

    The rheology of lower crust and its transient behavior in active strike-slip plate boundaries remain poorly understood. To address this issue, we analyzed a suite of granulite and lherzolite xenoliths from the upper Pleistocene-Holocene San Quintín volcanic field of northern Baja California, Mexico. The San Quintín volcanic field is located 20 km east of the Baja California shear zone, which accommodates the relative movement between the Pacific plate and Baja California microplate. The development of a strong foliation in both the mafic granulites and lherzolites, suggests that a lithospheric-scale shear zone exists beneath the San Quintín volcanic field. Combining microstructural observations, geothermometry, and phase equilibria modeling, we estimated that crystal-plastic deformation took place at temperatures of 750-890 °C and pressures of 400-560 MPa, corresponding to 15-22 km depth. A hot crustal geotherm of 40 ° C km-1 is required to explain the estimated deformation conditions. Infrared spectroscopy shows that plagioclase in the mafic granulites is relatively dry. Microstructures are interpreted to show that deformation in both the uppermost lower crust and upper mantle was accommodated by a combination of dislocation creep and grain-size-sensitive creep. Recrystallized grain size paleopiezometry yields low differential stresses of 12-33 and 17 MPa for plagioclase and olivine, respectively. The lower range of stresses (12-17 MPa) in the mafic granulite and lherzolite xenoliths is interpreted to be associated with transient deformation under decreasing stress conditions, following an event of stress increase. Using flow laws for dry plagioclase, we estimated a low viscosity of 1.1-1.3×1020 Pa ṡ s for the high temperature conditions (890 °C) in the lower crust. Significantly lower viscosities in the range of 1016-1019 Pa ṡ s, were estimated using flow laws for wet plagioclase. The shallow upper mantle has a low viscosity of 5.7×1019 Pa ṡ s

  5. Hematite (U-Th)/He thermochronometry constrains intraplate strike-slip faulting on the Kuh-e-Faghan Fault, central Iran

    Science.gov (United States)

    Calzolari, Gabriele; Rossetti, Federico; Ault, Alexis K.; Lucci, Federico; Olivetti, Valerio; Nozaem, Reza

    2018-03-01

    The Kuh-e-Faghan strike-slip fault system (KFF), located to the northern edge of the Lut Block in central Iran, developed through a Neogene-Quaternary pulsed history of eastward fault propagation and fault-related exhumation. This system is a consequence of the residual stresses transmitted from the Arabia-Eurasia convergent plate boundary. Here we integrate structural and textural analysis with new and previously published apatite fission-track (AFT) and apatite (U-Th)/He (apatite He) results, chlorite thermomentry, and hematite (U-Th)/He data from hematite-coated brittle fault surfaces to constrain the timing of tectonic activity and refine patterns of late Miocene-Pliocene burial and exhumation associated with the propagation of the KFF. Twenty-nine hematite (U-Th)/He (hematite He) dates from three striated hematite coated slip surfaces from the KFF fault core and damage zone yield individual dates from 12-2 Ma. Petrographic analysis and chlorite thermometry of a polyphase, fossil fluid system in the KFF fault core document that fluid circulation and mineralization transitioned from a closed system characterized by pressure solution and calcite growth to an open system characterized by hot hydrothermal (T = 239 ± 10 °C) fluids and hematite formation. Hematite microtextures and grain size analysis reveal primary and secondary syntectonic hematite fabrics, no evidence of hematite comminution and similar hematite He closure temperatures ( 60-85 °C) in each sample. Integration of these results with thermal history modeling of AFT and apatite He data shows that KFF activity in the late Miocene is characterized by an early stage of fault nucleation, fluid circulation, hematite mineralization, and eastward propagation not associated with vertical movement that lasted from 12 to 7 Ma. Hematite He, AFT, and apatite He data track a second phase of fault system activity involving fault-related exhumation initiating at 7 Ma and continuing until present time. Our new data

  6. Slip events propagating along a ductile mid-crustal strike-slip shear zone (Malpica-Lamego line, Variscan Orogen, NW Iberia)

    Science.gov (United States)

    Llana-Fúnez, Sergio; de Paola, Nicola; Pozzi, Giacomo; Lopez-Sanchez, Marco Antonio

    2017-04-01

    The current level of erosion in NW Iberian peninsula exposes Variscan mid-crustal depths, where widespread deformation during orogenesis produced dominantly ductile structures. It constitutes an adequate window for the observation of structures close to the brittle-plastic transition in the continental crust. The shear zone object of this work is the Malpica-Lamego line (MLL), a major Variscan structure formed in the late stages of the Variscan collision. The MLL is a mostly strike-slip major structure that offsets laterally by several kilometres the assembly of allochthonous complexes, that contain a sub-horizontal suture zone, which are the remnants of the plate duplication during the Variscan convergence. The shear zone is exposed along the northern coast of Galicia (NW Spain). It is characterized by phyllonites and quartz-mylonites in a zone which is tens of meters in thickness. Within the phyllonites, a few seams of cataclastic rocks have been found in bands along the main fabric. Their cohesive character, the parallelism between the different bands, the fact that host rocks maintain mineral assemblage and that no cross-cutting relations in the field were identified, are considered indicative of these brittle structures forming coetaneously with the ductile shearing producing the phyllonites. Samples from the phyllonites, also from quartz-mylonites, were prepared and powdered to characterize friction properties in a rotary shear apparatus at high, seismic velocities (m/s). Preliminary experiments run at room temperature and effective normal stresses between 10 to 25 MPa, show that friction coefficients µ are relatively high and a limited drop in friction coefficient occurs after 10-20 cm of slip, with µ decreasing from 0.7 to 0.5. Fracturing seems coetaneous with dominant ductile shearing within the shear zone, however, given the frictional properties of the phyllonites, it is unlikely that brittle deformation nucleates within these fault rocks. Instead, it

  7. Onshore-offshore seismic reflection profiling across the southern margin of the Sea of Japan: back-arc opening, shortening and active strike-slip deformation

    Science.gov (United States)

    Sato, Hiroshi; Ishiyama, Tatsuya; Kato, Naoko; Toda, Shigeru; Kawasaki, Shinji; Fujiwara, Akira; Tanaka, Yasuhisa; Abe, Susumu

    2017-04-01

    Pliocene to early Pleistocene along the limited fault system. The change in the direction of the motion of PHS at 1 Ma produced major change in stress regime from NS compression to EW compression in the back-arc. Following the change of stress regime, former reverse faults reactivated as strike-slip fault. Reuse of pre-existing faults are common, and crustal deformation concentrates relatively narrow zone in the back-arc failed rifts. Two-months after from our survey, Mw 6.2 Tottoriken-chubu earthquake occurred just beneath the onshore part of the seismic line. The source fault corresponds to the boundary of abrupt change in P-wave velocity, however there were no surface ruptures and distinctive geologic faults. The bottom of seismogenic layer corresponds to TWT 4.5 sec., which is almost the top horizon of reflective middle crust.

  8. The late Quaternary slip history of the North Anatolian Fault, Turkey: Implications for the spatial and temporal behaviour of large strike-slip fault belts

    Science.gov (United States)

    Zabcı, Cengiz; Akyüz, H. Serdar; Sançar, Taylan; Güneç Kıyak, Nafiye

    2015-04-01

    The study of the spatial and temporal behaviour of active faults by estimating the geologic and geodetic slip rates is critical not only for assessing the seismic potential of these tectonic structures, but also for understanding their geodynamics. Geodetic data can provide detailed spatial coverage but represent a short time interval of a single earthquake cycle, while geologic rates are derived as average values for multiple events at spatially limited sites. In the complex tectonic setting of the eastern Mediterranean, the westward extrusion of the Anatolian scholle is mainly accommodated by two major tectonic structures, the North Anatolian (NASZ) and the East Anatolian (EASZ) shear zones, respectively forming the northern and eastern boundaries. The rate of deformation all along the North Anatolian Fault (NAF) is spatially well documented mainly by GPS and InSAR based geodetic studies during the last two decades. Furthermore, the number of the morphochronology-based geologic slip rate studies significantly increased, covering the different sections of this large strike slip fault for various time intervals. In this study, we do not only compile all previous geologic slip rate estimates, but we also present data for three new and two revised sites from central to the most eastern parts of the NAF in order to understand the spatial and temporal behaviour of this important fault system. The integrated dataset of geologic studies were classified into two groups to represent the central to eastern sections (Model I) and the western part (Model II). The geographical diversion between two models is about at the 31° E longitude, where the NAF bifurcates into two branches from this point toward west into the Marmara Region. To test any secular variation in fault's slip history, we used the Monte Carlo approach of Gold and Cowgill (2011). After the removal of rates, which do not account the near fault deformation or the existing parallel/sub-parallel faults, the Model

  9. Analogue modelling of strike-slip fault propagation across a rheological/morphological crustal anisotropy: implications for the morphotectonic evolution of the Gloria Fault - Tore Madeira Rise area in NE Atlantic.

    Science.gov (United States)

    Tomás, Ricardo; Rosas, Filipe M.; Duarte, João C.; Terrinha, Pedro; Kullberg, Maria C.; Almeida, Jaime; Barata, Frederico; Carvalho, Bruno; Almeida, Pedro

    2015-04-01

    The Gloria Fault (GF) marks the E-W dextral transcurrent plate boundary between Eurasia and Africa in NE Atlantic, displaying complying high magnitude (historical and instrumental) seismic activity (e.g. M=7.1 in 1939 and M=8.4 in 1941, Bufforn et al., 1988), and cutting across a NNE-SSW 1000 km long bathymetric ridge: the so called Tore-Madeira Rise - TMR (rising in average 3km above the abyssal plain). The precise origin and tectono-magmatic evolution of the TMR is still not fully understood, although reported wide-angle refraction data points to a rheological configuration comprising an isostatically compensated thickened oceanic crust, possibly formed during a period of high accretion in the Mid-Atlantic Ridge (Pierce and Barton, 1991). Widespread evidence for volcanic activity has also been recognized, spanning from late Cretaceous to Present (Geldmacher et al. 2006, Merle et al. 2009), noticeably with the most recent volcanism (~500 Ky) occurring as tectonically aligned volcanic plugs, distributed along the E-W tectonic trend of the GF-related structures. To better understand the complex interference at play in this key area between the tectonic structures (essentially determined by the Gloria Fault system), the present and past magmatic activity and the resulting seafloor morphology, a series of dynamically scaled analogue modelling experiments have been conceived and carried out. The main focus of this experimental work was to decipher the potential influence of a rheological vs. morphological anisotropy (accounting for the TMR) on the lateral propagation of a major right-lateral strike-slip fault (representing the GF). The preliminary comparison of the obtained experimental results with the natural morphotectonic pattern in the study area reveals, not only a strong tectonic control of the ongoing volcanism, manifested by the observed preferred directions of aligned volcanic plugs, but also a so far unsuspected deflection/distributed pattern of several

  10. Mesozoic strike-slip movement of the Dunhua-Mishan Fault Zone in NE China: A response to oceanic plate subduction

    Science.gov (United States)

    Liu, Cheng; Zhu, Guang; Zhang, Shuai; Gu, Chengchuan; Li, Yunjian; Su, Nan; Xiao, Shiye

    2018-01-01

    The NE-striking Dunhua-Mishan Fault Zone (DMFZ) is one of two branches of the continental-scale sinistral Tan-Lu Fault Zone in NE China. The field data presented here indicate that the ca. 1000 km long DMFZ records two phases of sinistral faulting. The structures produced by these two phases of faulting include NE-SW-striking ductile shear belts and brittle faults, respectively. Mylonite-hosted microstructures and quartz c-axis fabrics suggest deformation temperatures of 450 °C-500 °C for the ductile shear belts. Combining new zircon U-Pb dates for 14 igneous rock samples analyzed during this study with the geology of this region indicates these shear belts formed during the earliest Early Cretaceous. This phase of sinistral displacement represents the initial formation of the DMFZ in response to the northward propagation of the Tan-Lu Fault Zone into NE China. A phase of Early Cretaceous rifting was followed by a second phase of sinistral faulting at 102-96 Ma, as evidenced by our new U-Pb ages for associated igneous rocks. Combining our new data with the results of previous research indicates that the DFMZ records a four-stage Cretaceous evolutionary history, where initial sinistral faulting at the beginning of the Early Cretaceous gave way to rifting during the rest of the Early Cretaceous. This was followed by a second phase of sinistral faulting at the beginning of the Late Cretaceous and a second phase of local rifting during the rest of the Late Cretaceous. The Cretaceous evolution of the DMFZ records the synchronous tectonic evolution of the NE China continent bordering the Pacific Ocean. Two phases of regional N-S compression generated the two phases of sinistral faulting within the DMFZ, whereas two-stage regional extension generated the two phases of rifting. The two compressive events were the result of the rapid low-angle subduction of the Izanagi and Pacific plates, whereas the two-stage extension was caused by the roll-back of these respective

  11. Vertical-axis rotations and deformation along the active strike-slip El Tigre Fault (Precordillera of San Juan, Argentina) assessed through palaeomagnetism and anisotropy of magnetic susceptibility

    Science.gov (United States)

    Fazzito, Sabrina Y.; Rapalini, Augusto E.; Cortés, José M.; Terrizzano, Carla M.

    2017-03-01

    Palaeomagnetic data from poorly consolidated to non-consolidated late Cenozoic sediments along the central segment of the active El Tigre Fault (Central-Western Precordillera of the San Juan Province, Argentina) demonstrate broad cumulative deformation up to 450 m from the fault trace and reveal clockwise and anticlockwise vertical-axis rotations of variable magnitude. This deformation has affected in different amounts Miocene to late Pleistocene samples and indicates a complex kinematic pattern. Several inherited linear structures in the shear zone that are oblique to the El Tigre Fault may have acted as block boundary faults. Displacement along these faults may have resulted in a complex pattern of rotations. The maximum magnitude of rotation is a function of the age of the sediments sampled, with largest values corresponding to middle Miocene-lower Pliocene deposits and minimum values obtained from late Pleistocene deposits. The kinematic study is complemented by low-field anisotropy of magnetic susceptibility data to show that the local strain regime suggests a N-S stretching direction, subparallel to the strike of the main fault.

  12. Excitation of tsunami by a pure strike-slip earthquake. ; Izu Oshima kinkai earthquake tsunami on Feb. 20, 1990. Yokozure danso jishin ni yoru tsunami no reiki. ; 1990 nen 2 gatsu 20 nichi Izu Oshima kinkai jishin tsunami

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K. (Nippon Dental University, Tokyo (Japan). Niigata Junior College); Okada, M. (Meteorological Research Institute, Tsukuba (Japan))

    1993-06-24

    A numerical experiment was performed to reproduce the tsunami from the Izu-Oshima Kinkai Earthquake which occurred on February 20, 1990, using a tsunami excited by a pure strike-slip fault. An existence of a vertical fault with a length of 15 km and a width of 12 km was hypothesized in the south-north direction on the ocean bottom around the focal region. Then, a tsunami was assumed to have been excited when the fault was given a side-slip movement to create discrepancies of 1 m in the fault. Water level change for one hour after onset of the tsunami was calculated in one-second interval in each unit square with a side length of 1 km over an ocean area of 200 km from east to west and 150 km from north to south centering on the wave source. The results obtained from the calculation were harmonious with tsunami waveforms observed at five stations in the subject region and their spectral analytic results. Reproduced were the two predominant frequencies commonly observed at more than two stations, and difference in predominant cycles that appear according to azimuths of the observation points to the epicenter. These facts endorse the reasonability of the above hypothesis. 9 refs., 11 figs.

  13. Paleoearthquakes on the Anninghe and Zemuhe fault along the southeastern margin of the Tibetan Plateau and implications for fault rupture behavior at fault bends on strike-slip faults

    Science.gov (United States)

    Wang, Hu; Ran, Yongkang; Chen, Lichun; Li, Yanbao

    2017-11-01

    Fault bends can serve as fault segment boundaries and are used in seismic hazard assessment. Recent studies addressing whether rupture propagation would be arrested at such structural complexities have commonly focused on computational modeling. However, multi-cycle paleoseismic rupture observations through fault bends have seldom been reported. In this study, we used trenching and radiocarbon dating to reveal paleoseismic rupture histories on the southern segment of the Anninghe fault (ANHF) along the southeastern margin of the Tibetan Plateau to explore multi-cycle surface rupture behavior at an extensional fault bend (with an angle of about 30°) at Xichang between the ANHF and Zemuhe fault (ZMHF). Specifically, nine trenches were opened in a fault depression at Maoheshan site and five paleoseismic events were identified. These have been named E1 through E5 respectively corresponding to events at 1400-935 BCE, 420-875 CE, 830-1360 CE, 1295-1715 CE, and 1790 CE-Present. After comparison with the historical records of earthquakes around Xichang and previous paleoseismic results, we suggest that the five seismic events are constrained at: 1365 BCE-935 BCE, 814 CE, 950 CE- 1145 CE, 1536 CE and 1850 CE, respectively. The average recurrence interval of earthquakes along the southern segment of the ANHF is about 700-800 yr. Furthermore, the evidence indicates that surface-faulting events along the southern segment of the ANHF appear to be unevenly spaced in time. Moreover, based on comparisons of seismic events along the ANHF and ZMHF, we find that two fault segments simultaneous ruptured during the 814 CE and 1850 CE earthquakes, event E3 and the 1536 CE earthquake ruptured the ANHF but not rupture the ZMHF. We suggest that the Xichang fault bend is not a persistent fault boundary, indicating that extensional fault bends with an angle of about 30° may not effectively terminate seismic ruptures on strike-slip faults.

  14. New Insights into Old Events: Improving Estimates of the Spatial Heterogeneity and Distribution of Co-Seismic Slip with Depth for Several Large Magnitude Strike-Slip Earthquakes using Geodetic Observations of the Near-Field Deformation.

    Science.gov (United States)

    Milliner, C. W. D.; Burgmann, R.; Wang, T.

    2016-12-01

    Finite-fault inversions of geodetic data to estimate co-seismic slip at depth, provide important information for faulting mechanics, understanding the behavior of the rupture process and constraints for dynamic rupture simulations. However, incorporating measurement of the near-field surface deformation has typically been difficult, due to decorrelation of the InSAR phase caused by complex ground deformation, and the difficulty of measuring diffuse, `off-fault' deformation in geologic field surveys. Such a lack of near-field data has been found to artificially generate deficits of shallow slip, by (a) overestimating slip at larger depths (3-8 km) by up to 30% [Xu et al. 2016], and (b) limiting the size of near-surface patches, with coarser meshes found to underestimate shallow slip [Huang et al. 2015], in turn distorting the spatial variation of slip across the rupture plane. Here we will present new results of kinematic slip inversions for the 1999 Mw 7.1 Hector Mine, 1999 Mw 7.6 Izmit and 2015 Mw 7.2 Tajikistan earthquakes using GPS data, SAR interferograms with refined phase unwrapping using SNAPHU, new SAR azimuth offsets, and optical image correlation results that can provide important near-field constraints of surface motion. Improved slip distributions for these large strike-slip earthquakes, which span a range of structural maturities, will allow us to assess whether more mature, `smoother' faults exhibit smoother slip distributions as predicted by quasi-static [Dieterich and Smith, 2009] and dynamic numerical rupture simulations [Dunham et al. 2011], and whether deficits of shallow slip are robust features. Understanding whether ruptures exhibit a deficit of shallow slip, and how the spatial heterogeneity of slip may vary between different fault systems holds significance for understanding how strain is released throughout the seismic cycle, generating realistic synthetic simulations of earthquake ruptures and the expected amount of ground shaking.

  15. Seismic attribute detection of faults and fluid pathways within an active strike-slip shear zone: New insights from high-resolution 3D P-Cable™ seismic data along the Hosgri Fault, offshore California

    Science.gov (United States)

    Kluesner, Jared W.; Brothers, Daniel

    2016-01-01

    Poststack data conditioning and neural-network seismic attribute workflows are used to detect and visualize faulting and fluid migration pathways within a 13.7 km2 13.7 km2 3D P-Cable™ seismic volume located along the Hosgri Fault Zone offshore central California. The high-resolution 3D volume used in this study was collected in 2012 as part of Pacific Gas and Electric’s Central California Seismic Imaging Project. Three-dimensional seismic reflection data were acquired using a triple-plate boomer source (1.75 kJ) and a short-offset, 14-streamer, P-Cable system. The high-resolution seismic data were processed into a prestack time-migrated 3D volume and publically released in 2014. Postprocessing, we employed dip-steering (dip and azimuth) and structural filtering to enhance laterally continuous events and remove random noise and acquisition artifacts. In addition, the structural filtering was used to enhance laterally continuous edges, such as faults. Following data conditioning, neural-network based meta-attribute workflows were used to detect and visualize faults and probable fluid-migration pathways within the 3D seismic volume. The workflow used in this study clearly illustrates the utility of advanced attribute analysis applied to high-resolution 3D P-Cable data. For example, results from the fault attribute workflow reveal a network of splayed and convergent fault strands within an approximately 1.3 km wide shear zone that is characterized by distinctive sections of transpressional and transtensional dominance. Neural-network chimney attribute calculations indicate that fluids are concentrated along discrete faults in the transtensional zones, but appear to be more broadly distributed amongst fault bounded anticlines and structurally controlled traps in the transpressional zones. These results provide high-resolution, 3D constraints on the relationships between strike-slip fault mechanics, substrate deformation, and fluid migration along an active

  16. Constraints on the rheology of the lower crust in a strike-slip plate boundary: evidence from the San Quintín xenoliths, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    T. van der Werf

    2017-12-01

    Full Text Available The rheology of lower crust and its transient behavior in active strike-slip plate boundaries remain poorly understood. To address this issue, we analyzed a suite of granulite and lherzolite xenoliths from the upper Pleistocene–Holocene San Quintín volcanic field of northern Baja California, Mexico. The San Quintín volcanic field is located 20 km east of the Baja California shear zone, which accommodates the relative movement between the Pacific plate and Baja California microplate. The development of a strong foliation in both the mafic granulites and lherzolites, suggests that a lithospheric-scale shear zone exists beneath the San Quintín volcanic field. Combining microstructural observations, geothermometry, and phase equilibria modeling, we estimated that crystal-plastic deformation took place at temperatures of 750–890 °C and pressures of 400–560 MPa, corresponding to 15–22 km depth. A hot crustal geotherm of 40 ° C km−1 is required to explain the estimated deformation conditions. Infrared spectroscopy shows that plagioclase in the mafic granulites is relatively dry. Microstructures are interpreted to show that deformation in both the uppermost lower crust and upper mantle was accommodated by a combination of dislocation creep and grain-size-sensitive creep. Recrystallized grain size paleopiezometry yields low differential stresses of 12–33 and 17 MPa for plagioclase and olivine, respectively. The lower range of stresses (12–17 MPa in the mafic granulite and lherzolite xenoliths is interpreted to be associated with transient deformation under decreasing stress conditions, following an event of stress increase. Using flow laws for dry plagioclase, we estimated a low viscosity of 1.1–1.3×1020 Pa ⋅ s for the high temperature conditions (890 °C in the lower crust. Significantly lower viscosities in the range of 1016–1019 Pa ⋅ s, were estimated using flow laws for wet plagioclase. The

  17. Strike slip faulting inferred from offsetting of drainages: Lower ...

    Indian Academy of Sciences (India)

    (a) Geological map of a part of lower Narmada valley showing disposition of active faults and structures (Agarwal. 1986). Red dotted box represents the area of figure 1(b). (b) Digital Elevation Model (DEM) of the part of Narmada valley showing various tectonic geomorphic features like fault scarp, palaeobank, linear valley ...

  18. Strike slip faulting inferred from offsetting of drainages: Lower ...

    Indian Academy of Sciences (India)

    The evolution of fault scarps, deformed rivers, marine terraces and the morphology of the moun- tain fronts have been studied for understanding neotectonic evolution of an area (Morisawa and. Hack 1985; Merritts and Hesterberg 1994; Keller and Printer 1996). Tricart (1974) discussed long- term effects of faulting and ...

  19. Strike slip faulting inferred from offsetting of drainages: Lower ...

    Indian Academy of Sciences (India)

    The detailed analysis of landforms,drainages and geology of the area between the rivers Amaravati and Karjan was carried out in order to understand the tectonic history of the lower Narmada basin. Movement along the various faults in the area was studied on the basis of the drainage offsetting. Horizontal offsetting of ...

  20. Significado tectónico y migración de fluidos hidrotermales en una red de fallas y vetas de un Dúplex de rumbo: un ejemplo del Sistema de Falla de Atacama Tectonic significance and hydrothermal fluid migration within a strike-slip duplex fault-vein network: an example from the Atacama Fault System

    Directory of Open Access Journals (Sweden)

    Viviana Olivares

    2010-07-01

    Full Text Available El Dúplex Caleta Coloso es una estructura de rumbo desarrollada durante la deformación frágil del Sistema de Falla de Atacama (SFA en el Cretácico Temprano. En su interior hay un sistema de vetas hidrotermales que documentan la naturaleza de la relación entre el transporte de fluidos y el desarrollo del dúplex. El sistema de vetas de orientación dominante NW se localiza en la roca de caja, adyacentes a las zonas de falla. Según su mineralogía dominante hay vetas de clorita, epidota-cuarzo y calcita-limonita, y según las relaciones de corte o su estructura interna, se definieron vetas tempranas (clorita, intermedias (epidota-cuarzo y tardías (calcita-limonitas. Algunas vetas muestran cristales perpendiculares u oblicuos a sus paredes (vetas de extensión y de extensión oblicua o fibras minerales orientadas paralelas a las estrías de las fallas (vetas-fallas. Estas últimas tienen indicadores cinemáticos compatibles con las fallas, evidenciando que fueron sincinemáticas con el desarrollo del dúplex. Según su microestructura, ellas se habrían formado en fracturas abiertas llenas de fluidos, bajo condiciones de presión inferior a la hidrostática, lo cual indicaría que la precipitación mineral ocurrió por caídas abruptas de la presión en una corteza somera (The Caleta Coloso Duplex is a brittle strike-slip structure developed along the Atacama Fault System during the Early Cretaceous. A hydrothermal vein system existing within the duplex documents the nature of the link between fluid transport and progressive structural development. The dominantly NW-striking vein system occurs near or at the damage zone of the duplex fault zones. Veins can be classified according to their composition and crosscutting relationships into early chlorite veins, intermediate epidotic-quartz veins and late calcite-limonite veins. Some of them exhibit minerals with their long axes oriented orthogonally or obliquely with respect to the vein walls

  1. Controls on timing and amount of right-lateral offset on the East Bay fault system, San Francisco Bay region, California

    Science.gov (United States)

    Graymer, R.W.; Sarna-Wojcicki, A. M.; Walker, J.P.; McLaughlin, R.J.; Fleck, R.J.

    2002-01-01

    The distribution of offset, correlated rock units, relative position of northward- younging volcanic rocks, and distribution of units not offset together reveal the history of strike-slip deformation along the East Bay fault system. The system accumulated 175 km of right-lateral offset since 12 Ma, but of this amount, only ???25 km was accumulated between 12 and 10 Ma and only ???75 km between 12 and 6 Ma. The westernmost Hayward fault zone is responsible for more than half (100 km) of the total, and it, too, has undergone more offset (60 km) after 6 Ma than before. The activity on any single fault zone in the system has been sporadic, and alternating periods of activity and inactivity have been recorded on at least some of the fault zones.

  2. Turkish earthquakes reveal dynamics of fracturing along a major strike-slip fault zone

    Science.gov (United States)

    Çemen, Ibrahim; Gökten, Ergun; Varol, Baki; Kiliç, Recep; Özaksoy, Volkan; Erkmen, Cenk; Pinar, Ali

    During the last 5 months of 1999, northwestern Turkey experienced two major earthquakes along the North Anatolian Fault Zone (NAFZ). The first earthquake struck the country at 3:01 A.M. local time on August 17, and caused extensive damage in the towns of Yalova, Gölcük, Izmit, Adapazari, and Düzce (Figure 1). The second earthquake occurred at 6:57 P.M. local time on November 12 and caused damage mostly in Düzce and Kaynasli.The 7.4-Mw main shock of the August 17 Izmit earthquake was centered at 40.702°N, 29.987°E and originated at a depth of 17 km. The center was about 11 km southeast of Izmit, a major industrial town (Figure 1). The earthquake was a devastating natural disaster that claimed close to 20,000 lives and left more than 100,000 people homeless.

  3. Deformation at a Complex Strike-Slip Plate Boundary: Modeling the Southern California GPS Velocity Field

    Science.gov (United States)

    Thatcher, W. R.; Murray-Moraleda, J. R.

    2009-12-01

    Because of EarthScope and related deployments, Southern California has perhaps the highest Global Positioning System (GPS) station density of any of Earth’s seismically active regions. Here we provide an updated analysis of the Southern California velocity field to illustrate both the strengths of high station density and the inherent limitations of surface geodetic measurements for quantifying earthquake-related deformation processes. Modeling GPS velocity fields in seismically active regions worldwide indicates deformation can be efficiently and usefully described as relative motions among elastic, fault-bounded crustal blocks. However, subjective choices of block geometry are unavoidable and introduce significant uncertainties in model formulation and in the resultant GPS fault slip rate estimates. To facilitate comparison between GPS and geologic results in southern California we use the SCEC Community Fault Model (CFM) and geologic slip rates tabulated in the 2008 Uniform California Earthquake Rupture Forecast (UCERF2) report as starting points for identifying the most important faults and specifying the block geometry. We then apply this geometry in an inversion of the SCEC Crustal Motion Model (CMM4) GPS velocity field to estimate block motions and intra-block fault slip rates and compare our results with previous work. In most parts of southern California—for example, north of the San Andreas Big Bend and SE of Los Angeles--our block geometry closely resembles that assumed in previous studies (McCaffrey 2005 JGR; Meade & Hager 2005 JGR; Becker et al. 2005 GJI). In these regions GPS slip rates can be reliably estimated and values for individual faults generally agree from one study to another and are also consistent with geologic estimates. However, there is no consensus on block geometry in the Transverse Ranges, Los Angeles Basin and Central Mojave Desert, where CFM faults are densely distributed, UCERF2 slip rates on several faults are comparable, and a simple block description may not be useful. It is notable that a number of documented disagreements between GPS and geologic slip rates occur on faults in these complex deforming zones (e.g. central Garlock fault, Eastern California Shear Zone, Big Bend San Andreas), in part reflecting the substantial epistemic uncertainty in GPS rate estimates for these faults. Our analysis suggests new GPS measurements and InSAR imaging that could refine slip rate estimates on a number of faults. However, in some cases GPS slip rate uncertainties are endemic and cannot be rectified by even higher station density or greater measurement precision. The difficulty arises because interseismic deformation is due to aseismic slip or localized ductile shearing on the down-dip extensions of faults that are locked (not slipping) in the seismogenic upper crust, smearing out the geodetically measured strain over a scale length of several times the locking depth of each fault (10-20 km). Where faults are closely spaced and slip at comparable rates, velocity gradients are quasi-uniform and the effects of individual faults cannot be distinguished. Better geologic slip rate constraints could ameliorate this non-uniqueness, but only under the assumption that geologic and GPS rates should agree.

  4. E-W strike slip shearing of Kinwat Granitoid at South East Deccan ...

    Indian Academy of Sciences (India)

    53

    detail/photo evidences nor any attitude data were presented. Tectonically active-, moderately active- and inactive basins have elongation ratios 0.75 ..... various types of interaction between coexisting felsic and mafic magmas. Earth and. Environmental Science Trans. Royal Soc. Edin. 83 145-153.

  5. E–W strike slip shearing of Kinwat granitoid at South East Deccan ...

    Indian Academy of Sciences (India)

    R D Kaplay

    2017-07-21

    Jul 21, 2017 ... Roy S and Rao R U M 1999 Geothermal investigations in the. 1993 Latur earthquake area, Deccan Volcanic Province,. India; Tectonophys. 306 237–252. Sangode S J, Mesharm D C, Kulkarni Y R, Gudadhe. S S, Malpe D B and Herlekar M A 2013 Neotectonic response of the Godavari and Kaddam Rivers ...

  6. Late-orogenic extension and strike-slip deformation in the Neogene of southeastern Spain

    NARCIS (Netherlands)

    Meijninger, B.M.L.

    2006-01-01

    The Betic Cordillera of southern Spain form the western end of the Alpine orogen, which during the Neogene was affected by large-scale late-orogenic extension. Extension, however, occurred within a setting of continuous slow convergence of the African and European plates. During the Neogene,

  7. Interactions between strike-slip earthquakes and the subduction interface near the Mendocino Triple Junction

    Science.gov (United States)

    Gong, Jianhua; McGuire, Jeffrey J.

    2018-01-01

    The interactions between the North American, Pacific, and Gorda plates at the Mendocino Triple Junction (MTJ) create one of the most seismically active regions in North America. The earthquakes rupture all three plate boundaries but also include considerable intraplate seismicity reflecting the strong internal deformation of the Gorda plate. Understanding the stress levels that drive these ruptures and estimating the locking state of the subduction interface are especially important topics for regional earthquake hazard assessment. However owing to the lack of offshore seismic and geodetic instruments, the rupture process of only a few large earthquakes near the MTJ have been studied in detail and the locking state of the subduction interface is not well constrained. In this paper, first, we use the second moments inversion method to study the rupture process of the January 28, 2015 Mw 5.7 earthquake on the Mendocino transform fault that was unusually well recorded by both onshore and offshore strong motion instruments. We estimate the rupture dimension to be approximately 6 km by 3 km corresponding to a stress drop of ∼4 MPa for a crack model. Next we investigate the frictional state of the subduction interface by simulating the afterslip that would be expected there as a result of the stress changes from the 2015 earthquake and a 2010 Mw 6.5 intraplate earthquake within the subducted Gorda plate. We simulate afterslip scenarios for a range of depths of the downdip end of the locked zone defined as the transition to velocity strengthening friction and calculate the corresponding surface deformation expected at onshore GPS monuments. We can rule out a very shallow downdip limit owing to the lack of a detectable signal at onshore GPS stations following the 2010 earthquake. Our simulations indicate that the locking depth on the slab surface is at least 14 km, which suggests that the next M8 earthquake rupture will likely reach the coastline and strong shaking should be expected there.

  8. Pseudodynamic Source Characterization for Strike-Slip Faulting Including Stress Heterogeneity and Super-Shear Ruptures

    KAUST Repository

    Mena, B.

    2012-08-08

    Reliable ground‐motion prediction for future earthquakes depends on the ability to simulate realistic earthquake source models. Though dynamic rupture calculations have recently become more popular, they are still computationally demanding. An alternative is to invoke the framework of pseudodynamic (PD) source characterizations that use simple relationships between kinematic and dynamic source parameters to build physically self‐consistent kinematic models. Based on the PD approach of Guatteri et al. (2004), we propose new relationships for PD models for moderate‐to‐large strike‐slip earthquakes that include local supershear rupture speed due to stress heterogeneities. We conduct dynamic rupture simulations using stochastic initial stress distributions to generate a suite of source models in the magnitude Mw 6–8. This set of models shows that local supershear rupture speed prevails for all earthquake sizes, and that the local rise‐time distribution is not controlled by the overall fault geometry, but rather by local stress changes on the faults. Based on these findings, we derive a new set of relations for the proposed PD source characterization that accounts for earthquake size, buried and surface ruptures, and includes local rise‐time variations and supershear rupture speed. By applying the proposed PD source characterization to several well‐recorded past earthquakes, we verify that significant improvements in fitting synthetic ground motion to observed ones is achieved when comparing our new approach with the model of Guatteri et al. (2004). The proposed PD methodology can be implemented into ground‐motion simulation tools for more physically reliable prediction of shaking in future earthquakes.

  9. E–W strike slip shearing of Kinwat granitoid at South East Deccan ...

    Indian Academy of Sciences (India)

    School of Earth Sciences, S.R.T.M. University, Nanded, Maharashtra 431 606, India. Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra 400 076, India. Nanded Education Society's Science College, Nanded, Maharashtra 431 606, India. Dnyanopasak College, Parbhani ...

  10. Evolution of the Rodgers Creek–Maacama right-lateral fault system and associated basins east of the northward-migrating Mendocino Triple Junction, northern California

    Science.gov (United States)

    McLaughlin, Robert J.; Sarna-Wojcicki, Andrei M.; Wagner, David L.; Fleck, Robert J.; Langenheim, V.E.; Jachens, Robert C.; Clahan, Kevin; Allen, James R.

    2012-01-01

    The Rodgers Creek–Maacama fault system in the northern California Coast Ranges (United States) takes up substantial right-lateral motion within the wide transform boundary between the Pacific and North American plates, over a slab window that has opened northward beneath the Coast Ranges. The fault system evolved in several right steps and splays preceded and accompanied by extension, volcanism, and strike-slip basin development. Fault and basin geometries have changed with time, in places with younger basins and faults overprinting older structures. Along-strike and successional changes in fault and basin geometry at the southern end of the fault system probably are adjustments to frequent fault zone reorganizations in response to Mendocino Triple Junction migration and northward transit of a major releasing bend in the northern San Andreas fault. The earliest Rodgers Creek fault zone displacement is interpreted to have occurred ca. 7 Ma along extensional basin-forming faults that splayed northwest from a west-northwest proto-Hayward fault zone, opening a transtensional basin west of Santa Rosa. After ca. 5 Ma, the early transtensional basin was compressed and extensional faults were reactivated as thrusts that uplifted the northeast side of the basin. After ca. 2.78 Ma, the Rodgers Creek fault zone again splayed from the earlier extensional and thrust faults to steeper dipping faults with more north-northwest orientations. In conjunction with the changes in orientation and slip mode, the Rodgers Creek fault zone dextral slip rate increased from ∼2–4 mm/yr 7–3 Ma, to 5–8 mm/yr after 3 Ma. The Maacama fault zone is shown from several data sets to have initiated ca. 3.2 Ma and has slipped right-laterally at ∼5–8 mm/yr since its initiation. The initial Maacama fault zone splayed northeastward from the south end of the Rodgers Creek fault zone, accompanied by the opening of several strike-slip basins, some of which were later uplifted and compressed

  11. Offset of latest pleistocene shoreface reveals slip rate on the Hosgri strike-slip fault, offshore central California

    Science.gov (United States)

    Johnson, Samuel Y.; Hartwell, Stephen R.; Dartnell, Peter

    2014-01-01

    The Hosgri fault is the southern part of the regional Hosgri–San Gregorio dextral strike‐slip fault system, which extends primarily in the offshore for about 400 km in central California. Between Morro Bay and San Simeon, high‐resolution multibeam bathymetry reveals that the eastern strand of the Hosgri fault is crossed by an ∼265  m wide slope interpreted as the shoreface of a latest Pleistocene sand spit. This sand spit crossed an embayment and connected a western fault‐bounded bedrock peninsula and an eastern bedrock highland, a paleogeography resembling modern coastal geomorphology along the San Andreas fault. Detailed analysis of the relict shoreface with slope profiles and slope maps indicates a lateral slip rate of 2.6±0.9  mm/yr, considered a minimum rate for the Hosgri given the presence of an active western strand. This slip rate indicates that the Hosgri system takes up the largest share of the strike‐slip fault budget and is the most active strike‐slip fault west of the San Andreas fault in central California. This result further demonstrates the value and potential of high‐resolution bathymetry in characterization of active offshore faults.

  12. Recurring extensional and strike-slip tectonics after the Neoproterozoic collisional events in the southern Mantiqueira province

    Directory of Open Access Journals (Sweden)

    Renato P. Almeida

    2012-06-01

    Full Text Available In Eastern South America, a series of fault-bounded sedimentary basins that crop out from Southern Uruguay to Southeastern Brazil were formed after the main collisional deformation of the Brasiliano Orogeny and record the tectonic events that affected the region from the Middle Ediacaran onwards. We address the problem of discerning the basin-forming tectonics from the later deformational events through paleostress analysis of more than 600 fault-slip data, mainly from the Camaquã Basin (Southern Brazil, sorted by stratigraphic level and cross-cutting relationships of superposed striations, and integrated with available stratigraphic and geochronological data. Our results show that the Camaquã Basin was formed by at least two distinct extensional events, and that rapid paleostress changes took place in the region a few tens of million years after the major collision (c.a. 630 Ma, probably due to the interplay between local active extensional tectonics and the distal effects of the continued amalgamation of plates and terranes at the margins of the still-forming Gondwana Plate. Preliminary paleostress data from the Castro Basin and published data from the Itajaí Basin suggest that these events had a regional nature.No Leste da América do Sul, um conjunto de bacias sedimentares que afloram do sul do Uruguai ao sudeste do Brasil formou-se após os eventos colisionais da Orogenia Brasiliana, registrando os eventos tectônicos que afetaram a região a partir do Mesoediacarano. O problema da distinção entre a tectônica formadora das bacias e os eventos deformacionais posteriores é aqui abordado através da análise de paleotensões de mais de 600 dados de falhas com estrias, obtidos principalmente na Bacia Camaquã (Sul do Brasil, que foram classificados por nível estratigráfico e relações de corte entre estrias sobrepostas, e intergrados a dados estratigráficos e geocronológicos disponíveis. Nossos resultados revelam que a Bacia Camaquã teve origem em ao menos dois eventos distensivos, e que modificações rápidas no campos de tensões ocorreram na região alguns poucos milhões de anos após a colisão principal (c.a. 630 Ma, provavelmente em decorrência da interação entre esforços distensivos locais e os efeitos distais da contínua amalgamação de placas e terrenos nas margens da placa Gondwana, ainda em formação. Dados preliminares de paleotensões da Bacia de Castro e dados publicados da Bacia Itajaí sugerem que esses eventos tiveram um caráter regional.

  13. A new multilayered visco-elasto-plastic experimental model to study strike-slip fault seismic cycle

    NARCIS (Netherlands)

    Caniven, Y.; Dominguez, S.; Soliva, R.; Cattin, R.; Peyret, M.; Marchandon, M.; Romano, C.; Strak, V.

    2015-01-01

    Nowadays, technological advances in satellite imagery measurements as well as the development of dense geodetic and seismologic networks allow for a detailed analysis of surface deformation associated with active fault seismic cycle. However, the study of earthquake dynamics faces several limiting

  14. Fault slip and earthquake recurrence along strike-slip faults — Contributions of high-resolution geomorphic data

    KAUST Repository

    Zielke, Olaf

    2015-01-01

    Understanding earthquake (EQ) recurrence relies on information about the timing and size of past EQ ruptures along a given fault. Knowledge of a fault\\'s rupture history provides valuable information on its potential future behavior, enabling seismic hazard estimates and loss mitigation. Stratigraphic and geomorphic evidence of faulting is used to constrain the recurrence of surface rupturing EQs. Analysis of the latter data sets culminated during the mid-1980s in the formulation of now classical EQ recurrence models, now routinely used to assess seismic hazard. Within the last decade, Light Detection and Ranging (lidar) surveying technology and other high-resolution data sets became increasingly available to tectono-geomorphic studies, promising to contribute to better-informed models of EQ recurrence and slip-accumulation patterns. After reviewing motivation and background, we outline requirements to successfully reconstruct a fault\\'s offset accumulation pattern from geomorphic evidence. We address sources of uncertainty affecting offset measurement and advocate approaches to minimize them. A number of recent studies focus on single-EQ slip distributions and along-fault slip accumulation patterns. We put them in context with paleoseismic studies along the respective faults by comparing coefficients of variation CV for EQ inter-event time and slip-per-event and find that a) single-event offsets vary over a wide range of length-scales and the sources for offset variability differ with length-scale, b) at fault-segment length-scales, single-event offsets are essentially constant, c) along-fault offset accumulation as resolved in the geomorphic record is dominated by essentially same-size, large offset increments, and d) there is generally no one-to-one correlation between the offset accumulation pattern constrained in the geomorphic record and EQ occurrence as identified in the stratigraphic record, revealing the higher resolution and preservation potential of the latter. While slip accumulation along a fault segment may be dominated by repetition of large, nearly constant offset increments, timing of surface-rupture is less regular. (C) 2014 Elsevier B.V. All rights reserved.

  15. Evidences of inclined transpression at the contact between ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 5. Evidences of inclined ... a right lateral strike-slip component. As a whole, it is suggested that Udayagiri group is thrusted over Vinjamuru group along a westerly dipping thrust plane with a right lateral strike-slip motion and simultaneous E–W contraction.

  16. Structural evolution of Cenozoic basins in northeastern Tunisia, in response to sinistral strike-slip movement on the El Alia-Teboursouk Fault

    Science.gov (United States)

    Bejaoui, Hamida; Aïfa, Tahar; Melki, Fetheddine; Zargouni, Fouad

    2017-10-01

    This paper resolves the structural complexity of Cenozoic sedimentary basins in northeastern Tunisia. These basins trend NE-SW to ∼ E-W, and are bordered by old fracture networks. Detailed descriptions of the structural features in outcrop and in subsurface data suggest that the El Alia-Teboursouk Fault zone in the Bizerte area evolved through a series of tectonic events. Cross sections, lithostratigraphic correlations, and interpretation of seismic profiles through the basins show evidence for: (i) a Triassic until Jurassic-Early Cretaceous rifting phase that induced lateral variations of facies and strata thicknesses; (ii) a set of faults oriented NE-SW, NW-SE, N-S, and E-W that guided sediment accumulation in pull-apart basins, which were subject to compressive and transpressive deformation during Eocene (Lutetian-Priabonian), Miocene (Tortonian), and Pliocene-Quaternary; and (iii) NNW-SSE to NS contractional events that occurred during the Late Pliocene. Part of the latest phase has been the formation of different synsedimentary folded structures with significant subsidence inversion. Such events have been responsible for the reactivation of inherited faults, and the intrusion of Triassic evaporites, ensuring the role of a slip layer. The combined effects of the different paleoconstraints and halokinetic movements are at the origin of the evolution of these pull-apart basins. The subsurface data suggest that an important fault displacement occurred during the Mesozoic-Cenozoic. The patterns of sediment accumulation in the different basins reflect a high activity of deep ancient faults.

  17. SHRIMP U-Pb zircon dating of Archean core complex formatio and pancratonic strike-slip deformation in the East Pilbara Granite-Greenstone Terrain

    NARCIS (Netherlands)

    Zegers, T.E.; Nelson, D.R.; Wijbrans, J.R.; White, S.H.

    2001-01-01

    Sensitive high-resolution ion microprobe (SHRIMP) U-Pb dating of zircons from granitic rocks in the East Pilbara Granite-Greenstone Terrain has provided time constraints for main tectonic events in the Shaw Granitoid Complex and has shown that deformation was intricately related to granitoid

  18. Ankara Orogenic Phase, Its Age and Transition From Thrusting-dominated Paleotectonic Period to the Strike-slip Neotectonic Period, Ankara (Turkey)

    OpenAIRE

    DEVECİ, ALİ KOÇYİĞİT & ŞULE

    2008-01-01

    The Ankara section of the İzmir-Ankara-Erzincan Suture Zone (IAESZ) is characterized by two major groups of contractional structures, namely the Ankara forced folds-monoclines and the southward-verging foreland fold-imbricate thrust to reverse fault zone (AFITFZ). In the Ankara region, one of the areas where the various phases of deformation and related structures are particularly well-preserved and exposed is the Edige (Elmadağ) area, 48 km east-southeast of the city of Ankara. The youngest ...

  19. Potassic late orogenic Stephanian volcanism in the South West french Massif Central (Decazeville, Figeac, Lacapelle-Marival basins): an example for mantle metasomatism along strike-slip faults?

    OpenAIRE

    Lapierre, Henriette; Basile, Christophe; Berly, Thomas; Canard, Emmanuel

    2008-01-01

    International audience; In the Southwestern part of the French Massif central (Decazeville basin, at the Sillon Houiller fault termination; Figeac and Lacapelle-Marival basins along the Argentat fault), Stephanian volcanism exhibits shoshonitic affinities. Their chondrite-normalized Rare Earth Element (REE) patterns are enriched in light REE, but almost flat for heavy REE, with marked negative Eu anomalies. Primitive mantle-normalized element spectra show negative Nb, Ta, P, Sm, Ti, and posit...

  20. The initiation and linkage of surface fractures above a buried strike ...

    Indian Academy of Sciences (India)

    In nature, these set ups roughly simulate a major strike slip basement fault system with a package of sedimentary rocks deforming by basement-induced wrenching and/or transpression. Models were made up of clay mixed with water in the ratio 3:1. Approximate undrained shear strength of the clay paste was around 2 KPa ...

  1. Right-lateralized brain oscillations in human spatial navigation.

    Science.gov (United States)

    Jacobs, Joshua; Korolev, Igor O; Caplan, Jeremy B; Ekstrom, Arne D; Litt, Brian; Baltuch, Gordon; Fried, Itzhak; Schulze-Bonhage, Andreas; Madsen, Joseph R; Kahana, Michael J

    2010-05-01

    During spatial navigation, lesion and functional imaging studies suggest that the right hemisphere has a unique functional role. However, studies of direct human brain recordings have not reported interhemisphere differences in navigation-related oscillatory activity. We investigated this apparent discrepancy using intracranial electroencephalographic recordings from 24 neurosurgical patients playing a virtual taxi driver game. When patients were virtually moving in the game, brain oscillations at various frequencies increased in amplitude compared with periods of virtual stillness. Using log-linear analysis, we analyzed the region and frequency specificities of this pattern and found that neocortical movement-related gamma oscillations (34-54 Hz) were significantly lateralized to the right hemisphere, especially in posterior neocortex. We also observed a similar right lateralization of gamma oscillations related to searching for objects at unknown virtual locations. Thus, our results indicate that gamma oscillations in the right neocortex play a special role in human spatial navigation.

  2. Levels of conflict in reasoning modulate right lateral prefrontal cortex.

    Science.gov (United States)

    Stollstorff, Melanie; Vartanian, Oshin; Goel, Vinod

    2012-01-05

    Right lateral prefrontal cortex (rlPFC) has previously been implicated in logical reasoning under conditions of conflict. A functional magnetic resonance imaging (fMRI) study was conducted to explore its role in conflict more precisely. Specifically, we distinguished between belief-logic conflict and belief-content conflict, and examined the role of rlPFC under each condition. The results demonstrated that a specific region of rlPFC is consistently activated under both types of conflict. Moreover, the results of a parametric analysis demonstrated that the same region was modulated by the level of conflict contained in reasoning arguments. This supports the idea that this specific region is engaged to resolve conflict, including during deductive reasoning. This article is part of a Special Issue entitled "The Cognitive Neuroscience of Thought". Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Geochemistry and composition of the Middle Devonian Srbsko Formation in Barrandian Area, Bohemian Massif: A trench or fore-arc strike-slip basin fill with material from volcanic arc of continental margin?

    Czech Academy of Sciences Publication Activity Database

    Strnad, L.; Hladil, Jindřich

    2001-01-01

    Roč. 13, - (2001), s. 111-114 ISSN 1210-9606. [Meeting of the Czech Tectonic Studies Group /6./. Donovaly - Nízké Tatry, 03.05.2001-06.05.2001] R&D Projects: GA AV ČR KSK3012103 Institutional research plan: CEZ:AV0Z3013912 Keywords : Geochemistry * tectonic setting * Srbsko Formation of the Barrandian area Subject RIV: DB - Geology ; Mineralogy http://geolines.gli.cas.cz/fileadmin/volumes/volume13/G13-111.pdf

  4. Using a UAV for collecting information about a deep-seated landslide in the island of Lefkada following the 17 November 2015 strike-slip earthquake (M=6.5)

    Science.gov (United States)

    Valkaniotis, Sotirios; Ganas, Athanassios; Papathanassiou, George

    2017-04-01

    Documentation of landslides is a very critical issue because effective protection and mitigation measures can be designed only if they are based on the accuracy of the provided information. Such a documentation aims at a detailed description of the basic geomorphological features e.g. edge, traces, scarp etc. while variables such as the landslide area and the volume of the area (that moved) are also measured. However, it is well known that the mapping of these features is not always feasible due to several adverse factors e.g. vertical slopes, high risk. In order to overcome this issue, remote sensing techniques were applied during the last decades. In particular, Interferometric Synthetic Aperture Radar (InSAR), Light Detection and Ranging (LiDAR) and photogrammetric surveys are used for geomorphic mapping in order to quantify landslide processes. The latter one, photogrammetric survey, is frequently conducted by use of Unmanned Aerial Vehicles (UAV), such as multicopters that are flexible in operating conditions and can be equipped with webcams, digital cameras and other sensors. In addition, UAV is considered as a low-cost imaging technique that offers a very high spatial-temporal resolution and flexibility in data acquisition programming. The goal of this study is to provide quantitative data regarding a deep-seated landslide triggered by the 17 November 2015, Greece earthquake (M=6.5; Ganas et al., 2016) in a coastal area of Lefkada, that was not accessible by foot and accordingly, a UAV was used in order to collect the essential information. Ganas, A., et al., Tectonophysics, http://dx.doi.org/10.1016/j.tecto.2016.08.012

  5. Effect of basement structure and salt tectonics on deformation styles along strike: An example from the Kuqa fold-thrust belt, West China

    Science.gov (United States)

    Neng, Yuan; Xie, Huiwen; Yin, Hongwei; Li, Yong; Wang, Wei

    2018-04-01

    The Kuqa fold-thrust belt (KFTB) has a complex thrust-system geometry and comprises basement-involved thrusts, décollement thrusts, triangle zones, strike-slip faults, transpressional faults, and pop-up structures. These structures, combined with the effects of Paleogene salt tectonics and Paleozoic basement uplift form a complex structural zone trending E-W. Interpretation and comprehensive analysis of recent high-quality seismic data, field observations, boreholes, and gravity data covering the KFTB has been performed to understand the characteristics and mechanisms of the deformation styles along strike. Regional sections, fold-thrust system maps of the surface and the sub-salt layer, salt and basement structure distribution maps have been created, and a comprehensive analysis of thrust systems performed. The results indicate that the thrust-fold system in Paleogene salt range can be divided into five segments from east to west: the Kela-3, Keshen, Dabei, Bozi, and Awate segments. In the easternmost and westernmost parts of the Paleogene salt range, strike-slip faulting and basement-involved thrusting are the dominant deformation styles, as basement uplift and the limits of the Cenozoic evaporite deposit are the main controls on deformation. Salt-core detachment fold-thrust systems coincide with areas of salt tectonics, and pop-up, imbricate, and duplex structures are associated with the main thrust faults in the sub-salt layer. Distribution maps of thrust systems, basement structures, and salt tectonics show that Paleozoic basement uplift controlled the Paleozoic foreland basin morphology and the distribution of Cenozoic salt in the KFTB, and thus had a strong influence on the segmented structural deformation and evolution of the fold-thrust belt. Three types of transfer zone are identified, based on the characteristics of the salt layer and basement uplift, and the effects of these zones on the fault systems are evaluated. Basement uplift and the boundary of

  6. Holocene earthquakes and right-lateral slip on the left-lateral Darrington-Devils Mountain fault zone, northern Puget Sound, Washington

    Science.gov (United States)

    Personius, Stephen F.; Briggs, Richard W.; Nelson, Alan R.; Schermer, Elizabeth R; Maharrey, J. Zebulon; Sherrod, Brian; Spaulding, Sarah A.; Bradley, Lee-Ann

    2014-01-01

    Sources of seismic hazard in the Puget Sound region of northwestern Washington include deep earthquakes associated with the Cascadia subduction zone, and shallow earthquakes associated with some of the numerous crustal (upper-plate) faults that crisscross the region. Our paleoseismic investigations on one of the more prominent crustal faults, the Darrington–Devils Mountain fault zone, included trenching of fault scarps developed on latest Pleistocene glacial sediments and analysis of cores from an adjacent wetland near Lake Creek, 14 km southeast of Mount Vernon, Washington. Trench excavations revealed evidence of a single earthquake, radiocarbon dated to ca. 2 ka, but extensive burrowing and root mixing of sediments within 50–100 cm of the ground surface may have destroyed evidence of other earthquakes. Cores in a small wetland adjacent to our trench site provided stratigraphic evidence (formation of a laterally extensive, prograding wedge of hillslope colluvium) of an earthquake ca. 2 ka, which we interpret to be the same earthquake documented in the trenches. A similar colluvial wedge lower in the wetland section provides possible evidence for a second earthquake dated to ca. 8 ka. Three-dimensional trenching techniques revealed evidence for 2.2 ± 1.1 m of right-lateral offset of a glacial outwash channel margin, and 45–70 cm of north-side-up vertical separation across the fault zone. These offsets indicate a net slip vector of 2.3 ± 1.1 m, plunging 14° west on a 286°-striking, 90°-dipping fault plane. The dominant right-lateral sense of slip is supported by the presence of numerous Riedel R shears preserved in two of our trenches, and probable right-lateral offset of a distinctive bedrock fault zone in a third trench. Holocene north-side-up, right-lateral oblique slip is opposite the south-side-up, left-lateral oblique sense of slip inferred from geologic mapping of Eocene and older rocks along the fault zone. The cause of this slip reversal is

  7. Platypnea-orthodeoxia syndrome in the right lateral decubitus position: a case report.

    Science.gov (United States)

    Tsuzuki, Ippei; Iigaya, Kamon; Matsubara, Takashi; Takagi, Shunsuke; Inohara, Taku; Ohgino, Yasuyuki; Imafuku, Toshio

    2017-04-12

    Platypnea-orthodeoxia syndrome is a rare syndrome characterized by dyspnea and hypoxia when the patient is sitting or standing. Here we report a case of platypnea-orthodeoxia syndrome caused by a right hemidiaphragmatic elevation with giant liver cyst that triggered a right-to-left shunt through the patent foramen ovale. This case report is the first presentation of a case secondary to hemidiaphragmatic elevation with giant liver cyst. In addition to this, a malposition of the pacemaker lead could be associated with platypnea-orthodeoxia syndrome in this case. A 91-year-old Japanese woman presented to our hospital with hypoxia of unknown origin. Severe hypoxia and cyanosis were observed only in the right lateral decubitus position. A chest X-ray and computed tomography scan revealed right hemidiaphragmatic elevation, which was probably compressing the right atrium. A transesophageal echocardiogram showed a compressed right atrium and shunt blood flow in both directions: from the left to the right atrium and vice versa. The shunt flow was exacerbated by postural changes from the left to the right lateral decubitus. A transesophageal echocardiogram also confirmed compression of the right atrium due to giant liver cyst and a malposition of the pacemaker lead abnormally placed in the left atrium through patent foramen ovale. We concluded that the cause of hypoxia was platypnea-orthodeoxia syndrome with right-to-left interatrial shunt through patent foramen ovale. Surgical closure of patent foramen ovale was not performed due to the age of our patient, surgical difficulties, and failure to obtain informed consent. For these reasons she was discharged after receiving medical advice about her posture. Platypnea-orthodeoxia syndrome is rare and difficult to diagnose. The present case suggests that hypoxia due to postural changes should be considered a differential diagnosis of platypnea-orthodeoxia syndrome.

  8. [Papillary Carcinoma Arising in Thyroglossal Duct Cyst in the Right Lateral Neck].

    Science.gov (United States)

    Wakasa, Yusuke; Oishi, Susumu; Nara, Masaki; Nozaki, Tsuyoshi; Yoshihara, Shuichi; Tateoka, Hiroshi

    2017-11-01

    A 47-year-old woman was admitted to our institution with the chief complaint of a right cervical mass. Imaging examination findings showed a cystic mass of 25mm with a nodular lesion in the right cervical region. Therefore, we performed extirpation of the right cervical cystic mass to allow diagnosis of the lesion. The histopathological findings showed a partial thyroid tissue on the cyst wall covered with glandular epithelium or metaplastic squamous epithelium, and tumor cells proliferating in the papillary form. Considering the histopathological evidence of the characteristic epithelium of the thyroglossal duct cyst, the potential carcinogenesis from the remnant thyroid tissues, and the absence of primary tumor in the thyroid gland, the patient was diagnosed with thyroid papillary carcinoma arising from the thyroglossal duct cyst in the right lateral cervical region. We found recurrence of the right cervical lymph node at 1 year and 5 months after the initial operation. Thus, we performed dissection of the right cervical lymph nodes. Two years and 10 months after the operation, neither recurrence nor metastasis have been observed. It was suggested that, thyroid papillary carcinoma arising from the thyroglossal duct cyst should be taken into consideration when a lateral cervical mass lesion is found.

  9. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Pseudotachylytes, as well as the country rock, bear the evidence of conjugate strike slip shearing along NNE–SSW and NW–SE directions, suggesting an N–S compression. The Gangavalli Shear Zone represents the NNE–SSW fault of the conjugate system along which a right lateral shear has produced seismic slip motion ...

  10. Arc parallel extension in Higher and Lesser Himalayas, evidence ...

    Indian Academy of Sciences (India)

    They are represented by arcperpendicular normal faults and arc-parallel sinistral strike-slip faults. We discuss ... The partitioning of stress due to oblique convergence is argued based on evidences of left-lateral slip in NEHimalaya, right-lateral slip in NW-Himalaya and absence of translation in the central part. The amount of ...

  11. Magnetotelluric impedance tensor analysis for identification of ...

    Indian Academy of Sciences (India)

    G Pavan Kumar

    2017-07-18

    Jul 18, 2017 ... of three uplifts: (1) the Island Belt Fault Zone;. (2) the Kachchh Mainland uplift, and (3) the. Wagad uplift (figure 1). The Island Belt Fault. Zone comprises of four islands, viz., Pachchham,. Khadir, Bela and Chorar, controlled and separated by the right-lateral transverse and strike-slip faults. (figure 1) (Biswas ...

  12. Structure of the Hat Creek graben region: Implications for the structure of the Hat Creek graben and transfer of right-lateral shear from the Walker Lane north of Lassen Peak, northern California, from gravity and magnetic anomalies

    Science.gov (United States)

    Langenheim, Victoria; Jachens, Robert C.; Clynne, Michael A.; Muffler, L. J. Patrick

    2016-01-01

    Interpretation of magnetic and new gravity data provides constraints on the geometry of the Hat Creek Fault, the amount of right-lateral offset in the area between Mt. Shasta and Lassen Peak, and confirmation of the influence of pre-existing structure on Quaternary faulting. Neogene volcanic rocks coincide with short-wavelength magnetic anomalies of both normal and reversed polarity, whereas a markedly smoother magnetic field occurs over the Klamath Mountains and its Paleogene cover. Although the magnetic field over the Neogene volcanic rocks is complex, the Hat Creek Fault, which is one of the most prominent normal faults in the region and forms the eastern margin of the Hat Creek Valley, is marked by the eastern edge of a north-trending magnetic and gravity high 20-30 km long. Modeling of these anomalies indicates that the fault is a steeply dipping (~75-85°) structure. The spatial relationship of the fault as modeled by the potential-field data, the youngest strand of the fault, and relocated seismicity suggests that deformation continues to step westward across the valley, consistent with a component of right-lateral slip in an extensional environment. Filtered aeromagnetic data highlight a concealed magnetic body of Mesozoic or older age north of Hat Creek Valley. The body’s northwest margin strikes northeast and is linear over a distance of ~40 km. Within the resolution of the aeromagnetic data (1-2 km), we discern no right-lateral offset of this body. Furthermore, Quaternary faults change strike or appear to end, as if to avoid this concealed magnetic body and to pass along its southeast edge, suggesting that pre-existing crustal structure influenced younger faulting, as previously proposed based on gravity data.

  13. Pan-African deformations in the basement of the Negele area, southern Ethiopia

    Science.gov (United States)

    Yihunie, Tadesse

    2002-03-01

    Polydeformed and metamorphosed Neoproterozoic rocks of the East African Orogen in the Negele area constituted three lithostructurally distinct and thrust-bounded terranes. These are, from west to east, the Kenticha, Alghe and Bulbul terranes. The Kenticha and Bulbul terranes are metavolcano-sedimentary and ultramafic sequences, representing parts of the Arabian-Nubian Shield (ANS), which are welded to the central Alghe gneissic terrane of the Mozambique Belt affinity along N-S-trending sheared thrust contacts. Structural data suggest that the Negele basement had evolved through three phases of deformation. During D1 (folding) deformation, north-south upright and inclined folds with north-trending axes were developed. East and west-verging thrusts, right-lateral shearing along the north-oriented Kenticha and Bulbul thrust contacts and related structural elements were developed during D2 (thrusting) deformation. The pervasive D1 event is interpreted to have occurred at 620-610 Ma and the D2 event ended prior to 554 Ma. Right-lateral strike-slips along thrust contacts are interpreted to have been initiated during late D2. During D3, left-lateral strike-slip along the Wadera Shear Zone and respective strike-slip movements along conjugate set of shear zones were developed in the Alghe terrane, and are interpreted to have occurred later than 557 Ma. The structural data suggest that eastward thrusting of the Kenticha and westward tectonic transport of the Bulbul sequences over the Alghe gneissic terrane of the Mozambique Belt, during D2, were accompanied by right-lateral strike-slip displacements along thrust contacts. Right-lateral strike-slip movements along the Kenticha thrust contact, further suggest northward movement of the Kenticha sequence during the Pan-African orogeny in the Neoproterozoic. Left-lateral strike-slip along the orogen-parallel NNE-SSW Wadera Shear Zone and strike-slip movements along a conjugate set of shear zones completed final terrane

  14. An effective and safe gastric endoscopic submucosal dissection in the right lateral position using an inverted overtube.

    Science.gov (United States)

    Mori, Hirohito; Rafiq, Kazi; Kobara, Hideki; Nishiyama, Noriko; Fujihara, Shintaro; Yachida, Tatsuo; Ayagi, Maki; Tani, Joji; Miyoshi, Hisaaki; Masaki, Tsutomu

    2014-02-14

    Previously, we reported the efficacy of a newly developed inverted overtube in shortening the hemostatic time and obtaining a clear endoscopic view in emergency endoscopic hemostasis. This device also helped us to perform gastric endoscopic submucosal dissection (ESD) more safely by changing the direction of gravity in the right lateral position. To perform a safe ESD, it is important to make an appropriate angle and distance between the electric knife and the gastric mucosa. In this position, the distance to gastric mucosa is reduced, and the angle of the electric knife changes from vertical to somewhat oblique, facilitating safer cutting.

  15. Lightning Often Strikes Twice

    Science.gov (United States)

    2005-01-01

    Contrary to popular misconception, lightning often strikes the same place twice. Certain conditions are just ripe for a bolt of electricity to come zapping down; and a lightning strike is powerful enough to do a lot of damage wherever it hits. NASA created the Accurate Location of Lightning Strikes technology to determine the ground strike point of lightning and prevent electrical damage in the immediate vicinity of the Space Shuttle launch pads at Kennedy Space Center. The area surrounding the launch pads is enmeshed in a network of electrical wires and components, and electronic equipment is highly susceptible to lightning strike damage. The accurate knowledge of the striking point is important so that crews can determine which equipment or system needs to be retested following a strike. Accurate to within a few yards, this technology can locate a lightning strike in the perimeter of the launch pad. As an added bonus, the engineers, then knowing where the lightning struck, can adjust the variables that may be attracting the lightning, to create a zone that will be less susceptible to future strikes.

  16. Right away: A late, right-lateralized category effect complements an early, left-lateralized category effect in visual search.

    Science.gov (United States)

    Constable, Merryn D; Becker, Stefanie I

    2017-10-01

    According to the Sapir-Whorf hypothesis, learned semantic categories can influence early perceptual processes. A central finding in support of this view is the lateralized category effect-namely, the finding that categorically different colors (e.g., blue and green hues) can be discriminated faster than colors within the same color category (e.g., different hues of green), especially when they are presented in the right visual field. Because the right visual field projects to the left hemisphere, this finding has been popularly couched in terms of the left-lateralization of language. However, other studies have reported bilateral category effects, which has led some researchers to question the linguistic origins of the effect. Here we examined the time course of lateralized and bilateral category effects in the classical visual search paradigm by means of eyetracking and RT distribution analyses. Our results show a bilateral category effect in the manual responses, which is combined of an early, left-lateralized category effect and a later, right-lateralized category effect. The newly discovered late, right-lateralized category effect occurred only when observers had difficulty locating the target, indicating a specialization of the right hemisphere to find categorically different targets after an initial error. The finding that early and late stages of visual search show different lateralized category effects can explain a wide range of previously discrepant findings.

  17. Options with Extreme Strikes

    Directory of Open Access Journals (Sweden)

    Lingjiong Zhu

    2015-07-01

    Full Text Available In this short paper, we study the asymptotics for the price of call options for very large strikes and put options for very small strikes. The stock price is assumed to follow the Black–Scholes models. We analyze European, Asian, American, Parisian and perpetual options and conclude that the tail asymptotics for these option types fall into four scenarios.

  18. Should doctors strike?

    Science.gov (United States)

    Park, John J; Murray, Scott A

    2014-05-01

    Last year in June, British doctors went on strike for the first time since 1975. Amidst a global economic downturn and with many health systems struggling with reduced finances, around the world the issue of public health workers going on strike is a very real one. Almost all doctors will agree that we should always follow the law, but often the law is unclear or does not cover a particular case. Here we must appeal to ethical discussion. The General Medical Council, in its key guidance document for practising doctors, Good Medical Practice, claims that 'Good doctors make the care of their patients their first concern'. Is this true? And if so, how is this relevant to the issue of striking? One year on since the events, we carefully reflect and argue whether it was right for doctors to pursue strike action, and call for greater discussion of ethical issues such as the recent strikes, particularly among younger members of the profession.

  19. Volumetric analysis of colonic distention according to patient position at CT colonography: diagnostic value of the right lateral decubitus series.

    Science.gov (United States)

    Pickhardt, Perry J; Bakke, Joshua; Kuo, Jarret; Robbins, Jessica B; Lubner, Meghan G; del Rio, Alejandro Muñoz; Kim, David H

    2014-12-01

    The purpose of this study was to compare total colonic gas volume and segmental luminal distention according to patient position on CT colonography (CTC), as well as to determine which two views should constitute the routine protocol. Volumetric analysis was retrospectively performed on CTC examinations from 146 adults (mean age, 59.2 years; 81 men and 65 women; mean body mass index [BMI], 30.9) for whom supine, prone, and right lateral decubitus series were sequentially obtained using continuous low-pressure CO2 insufflation. Total colonic gas volumes were assessed using a novel automated volumetric tool. In addition, two radiologists scored distention by segment using a 4-point scale (4=optimal; 3=adequate; 2=inadequate; 1=collapsed). Mean (±SD) colonic gas volumes for supine, prone, and decubitus positioning were 1617±567, 1441±505, and 1901±627, respectively (pvolumetric analysis provides for rapid objective assessment of colonic distention.

  20. Volumetric Analysis of Colonic Distention According to Patient Position at CTC: Diagnostic Value of the Right Lateral Decubitus Series

    Science.gov (United States)

    Pickhardt, Perry J.; Bakke, Joshua; Kuo, Jarret; Robbins, Jessica B.; Lubner, Meghan G.; Muñoz del Rio, Alejandro; Kim, David H.

    2017-01-01

    Purpose To compare total colonic gas volume and segmental luminal distention according to patient position at CT colonography (CTC), and determine which two views should constitute the routine protocol. Methods Volumetric analysis was retrospectively performed on CTC examinations from 146 adults (mean age, 59.2 years; 81M/65F; mean BMI, 30.9) where supine, prone, and right lateral decubitus series were sequentially obtained using continuous low-pressure CO2 insufflation. Total colonic gas volumes were assessed using a novel automated volumetric tool. In addition, two radiologists scored distention by segment using a 4-point scale (4=Optimal/3=Adequate/2=Inadequate/1=Collapsed). Results Mean colonic gas volume (±SD) for supine, prone, and decubitus positioning was 1,617±567 ml, 1441±505 ml, and 1901±627 ml, respectively (pvolumetric analysis provides for rapid objective assessment of colonic distention. PMID:25415727

  1. The Effects of Pre-stress Assumptions on Dynamic Rupture with Complex Fault Geometry in the San Gorgonio Pass, CA Region

    Science.gov (United States)

    Kyriakopoulos, C.; Tarnowski, J. M.; Oglesby, D. D.

    2016-12-01

    We use 3D dynamic finite element models to investigate potential rupture paths of earthquakes propagating along faults in the western San Gorgonio Pass (SGP) region. The SGP is a structurally complex region along the San Andreas fault system (SAF) in southern California. We focus on the San Bernardino strand of the SAF, the San Gorgonio Pass Fault Zone, and a portion of the Garnet Hill strand of the SAF. The San Bernardino and Garnet Hill strands are predominately right-lateral strike-slip faults. Thrust faults dominate the San Gorgonio Pass Fault Zone, with small right-lateral tear faults between the thrust faults. We use the finite element code FaultMod (Barall, 2009) to observe differences in rupture propagation along a meshed fault geometry that reflects most of the surface trace complexity. We test three different types of pre-stress assumptions: 1) constant tractions, 2) regional stress regimes, and 3) long-term stressing rates from quasi-static crustal deformation modeling. Models with constant tractions assume pure right-lateral strike-slip motion on the San Bernardino and Garnet Hill strands and oblique thrust/right-lateral strike-slip motion on the San Gorgonio Pass Fault Zone. Preliminary results from models with constant tractions suggest that the complexity of the fault geometry may inhibit rupture propagation, depending on nucleation location.

  2. Strong paleoearthquakes along the Talas-Fergana Fault, Kyrgyzstan

    Directory of Open Access Journals (Sweden)

    A.M. Korzhenkov

    2014-02-01

    Full Text Available The Talas-Fergana Fault, the largest strike-slip structure in Centred. Asia, forms an obliquely oriented boundary between the northeastern and southwestern parts of the Tianshan mountain belt. The fault underwent active right-lateral strike-slip during the Paleozoic, with right-lateral movements being rejuvenated in the Late Cenozoic. Tectonic movements along the intracontinental strike-slip faults contribute to absorb part of the regional crustal shortening linked to the India-Eurasia collision; knowledge of strike-slip motions along the Talas-Fergana Fault are necessary for a complete assessment of the active deformation of the Tianshan orogen. To improve our understanding of the intracontinental deformation of the Tianshan mountain belt and the occurrence of strong earthquakes along the whole length of the Talas-Fergana Fault, we identify features of relief arising during strong paleoearthquakes along the Talas-Fergana Fault, fault segmentation, the length of seismogenic ruptures, and the energy and age of ancient catastrophes. We show that during neotectonic time the fault developed as a dextral strike-slip fault, with possible dextral displacements spreading to secondary fault planes north of the main fault trace. We determine rates of Holocene and Late Pleistocene dextral movements, and our radiocarbon dating indicates tens of strong earthquakes occurring along the fault zone during arid interval of 15800 years. The reoccurrence of strong earthquakes along the Talas-Fergana Fault zone during the second half of the Holocene is about 300 years. The next strong earthquake along the fault will most probably occur along its southeastern chain during the next several decades. Seismotectonic deformation parameters indicate that M > 7 earthquakes with oscillation intensity I > IX have occurred.

  3. A right to strike?

    Science.gov (United States)

    Jennings, K; Western, G

    1997-07-01

    During 1995, there was a major shift in the United Kingdom in the debate of whether it is right for nurses to strike. The Royal College of Nursing, the former advocate of a non-industrial action policy, moved towards the UNISON position that industrial action is ethical in some circumstances, as well as the necessary thing to do. The authors, both nurses and UNISON officials, look at the reasons for this change and why UNISON's historical position sees industrial action as an effective weapon in defending services, as well as wages and jobs. It can be right to strike.

  4. Characteristics of the active Luoshan Fault since Late Pleistocene, North Central China

    Directory of Open Access Journals (Sweden)

    M. Fengying

    2003-06-01

    Full Text Available The Luoshan Fault located at the northeastern margin of Tibet plateau strikes roughly N-S, and is composed of six left-stepping sections with a total length of 60 km. Much evidence suggests that the Luoshan Fault is a reverse right-lateral strike-slip fault. The largest right-lateral strike-slip displacement and the most abundant dextral offset phenomena are located along the central section. Based on the right-lateral strike-slip offsets of the oldest alluvial fan, and of a gully and on the average displacement of the same order of gullies, the minimum slip-rate has been 2.15 ± 0.2 mm/yr since Late Pleistocene. Many surface rupture phenomena, such as fault scarps with fresh free-face, ground fissures, displacements of very young gullies, imply that a recent earthquake occurred along this fault. Combining the historical catalogue and our results, we believe that the 1561 A.D. earthquake was produced by the Luoshan Fault. Three paleoearthquakes were determined by means of paleoseismic studies along the Luoshan Fault: they occurred after 8200 ± 600 years BP, between 3130 ± 240 years BP and 4150 ± ± 120 years C.BP, and before 2230 ± 170 years BP, respectively.

  5. Constraints from Mesozoic siliciclastic cover rocks and satellite image analysis on the slip history of regional E-W faults in the southeast Western Desert, Egypt

    Science.gov (United States)

    Tewksbury, Barbara J.; Mehrtens, Charlotte J.; Gohlke, Steven A.; Tarabees, Elhamy A.; Hogan, John P.

    2017-12-01

    In the southeast Western Desert of Egypt, a prominent set of E-W faults and co-located domes and basins involve sedimentary cover rock as young as the early Eocene. Although earlier Mesozoic slip on faults in southern Egypt has been widely mentioned in the literature and attributed to repeated reactivation of basement faults, evidence is indirect and based on the idea that regional stresses associated with tectonic events in the Syrian Arc would likely have reactivated basement faults in south Egypt in dextral strike slip during the Mesozoic as well as the Cenozoic. Here, we present direct evidence from the rock record for the sequence of development of features along these faults. Southwest of Aswan, a small structural dome in Mesozoic Nubia facies rocks occurs where the Seiyal Fault bends northward from west to east. The dome is cut by strands of the Seiyal Fault and a related set of cataclastic deformation bands showing dominantly right lateral strike slip, as well as by younger calcite veins with related patchy poikilotopic cement. High resolution satellite image analysis of the remote southwest Kharga Valley shows a similar sequence of events: older structural domes and basins located where E-W faults bend northward from west to east, right lateral offset of domes and basins along the E-W faults, and two sets of deformation band faults that lack co-located domes and basins. We suggest that field data, image analysis, and burial depth estimates are best explained by diachronous development of features along the E-W fault system. We propose that Late Mesozoic right lateral strike slip produced domes and basins in Nubia facies rocks in stepover regions above reactivated basement faults. We further suggest that the extensively linked segments of the E-W fault system in Nubia facies rocks, plus the deformation band systems, formed during the late Eocene when basement faults were again reactivated in dominantly right lateral strike slip.

  6. Active faults pattern and interplay in the Azerbaijan region (NW Iran)

    Science.gov (United States)

    Faridi, M.; Burg, J.-P.; Nazari, H.; Talebian, M.; Ghorashi, M.

    2017-07-01

    Northwest Iran is dominated by two main sets of active strike slip faults that accommodate oblique convergence between the Arabian and Iranian Plates. The best known are the right-lateral North-Tabriz, Qoshadagh, Maragheh and Zagros (Main Recent) strike slip Faults. This work reports that these dominant NW-SE to E-W striking faults are conjugate to smaller, NNE-SSW striking, left-lateral faults with minor dip slip component. All of these active faults displace Precambrian rock units, which suggests that they root in the crystalline basement of the NW Iranian microcontinent. Coulomb stress variance during co-seismic rupture along one of these faults may cause reactivation of the other faults. The minor set of left-lateral fault is therefore important to introduce in seismic risk assessment.

  7. Algab õppus "Saber Strike"

    Index Scriptorium Estoniae

    2014-01-01

    Täna algab Eestis, Lätis ja Leedus Ameerika Ühendriikide Euroopa väekoondise õppus "Saber Strike", mille eesmärk on maaväeüksuste koostöö harjutamine. Õppusest võtab osa üle 2000 kaitseväelase Baltimaadest, USAst, Ühendkuningriigist, Taanist, Norrast, Soomest ja Saksamaalt. Eestist osaleb õppusel ligi 400 kaitseväelast

  8. Global strike hypersonic weapons

    Science.gov (United States)

    Lewis, Mark J.

    2017-11-01

    Beginning in the 1940's, the United States has pursued the development of hypersonic technologies, enabling atmospheric flight in excess of five times the speed of sound. Hypersonic flight has application to a range of military and civilian applications, including commercial transport, space access, and various weapons and sensing platforms. A number of flight tests of hypersonic vehicles have been conducted by countries around the world, including the United States, Russia, and China, that could lead the way to future hypersonic global strike weapon systems. These weapons would be especially effective at penetrating conventional defenses, and could pose a significant risk to national security.

  9. Impulse of a Kendo Strike

    Directory of Open Access Journals (Sweden)

    Masahiro Abe

    2012-06-01

    Full Text Available An expert swordsman struck a target with a kendo sword. The velocity and force of the strike were measured. The relationship between the strike velocity, impact force and effective mass of the sword was investigated. It was shown that the effective mass of the sword remains constant for typical strike velocities.

  10. Tectonics and paleogeography along the Amazon river

    Science.gov (United States)

    Costa, João Batista Sena; Léa Bemerguy, Ruth; Hasui, Yociteru; da Silva Borges, Maurício

    2001-09-01

    The main structural and geomorphological features along the Amazon River are closely associated with Mesozoic and Cenozoic tectonic events. The Mesozoic tectonic setting is characterised by the Amazonas and Marajó Basins, two distinct extensional segments. The Amazonas Basin is formed by NNE-SSW normal faults, which control the emplacement of dolerite dykes and deposition of the sedimentary pile. In the more intense tectonic phase (mid-Late Cretaceous), the depocentres were filled with fluvial sequences associated with axial drainage systems, which diverge from the Lower Tapajós Arch. During the next subsidence phase, probably in the Early Tertiary, and under low rate extension, much of the drainage systems reversed, directing the paleo-Amazon River to flow eastwards. The Marajó Basin encompasses NW-SE normal faults and NE-SW strike-slip faults, with the latter running almost parallel to the extensional axes. The normal faults controlled the deposition of thick rift and post-rift sequences and the emplacement of dolerite dykes. During the evolution of the basin, the shoulder (Gurupá Arch) became distinct, having been modelled by drainage systems strongly controlled by the trend of the strike-slip faults. The Arari Lineament, which marks the northwest boundary of the Marajó Basin, has been working as a linkage corridor between the paleo and modern Amazon River with the Atlantic Ocean. The neotectonic evolution since the Miocene comprises two sets of structural and geomorphological features. The older set (Miocene-Pliocene) encompasses two NE-trending transpressive domains and one NW-trending transtensive domain, which are linked to E-W and NE-SW right-lateral strike-slip systems. The transpressive domains display aligned hills controlled by reverse faults and folds, and are separated by large plains associated with pull-apart basins along clockwise strike-slip systems (e.g. Tupinambarana Lineament). Many changes were introduced in the landscape by the

  11. Fluid Collection in the Right Lateral Portion of the Superior Aortic Recess Mimicking a Right Mediastinal Mass: Assessment with Chest Posterior Anterior and MDCT

    International Nuclear Information System (INIS)

    Shn, Dong Rock; Ryu, Dae Shick; Park, Man Soo; Jung, Seung Mun; Ahn, Jae Hong; Lee, Jong Hyeog; Choi, Soo Jung

    2012-01-01

    We observed patients in whom the fluid collection in the right lateral portion of the superior aortic recess on computed tomography (CT) scans mimicked a right anterior mediastinal mass on chest PA radiographs. The purpose of this study was to assess chest PA and CT features of these patients. All chest PA radiographs and CT scans in 9 patients were reviewed by two radiologists on a consensus basis; for the presence of pleural effusion, pulmonary edema and heart size on chest PA radiographs. For the portion of the fluid collection in the superior aortic recess (SAR), a connection between the right lateral portion of the SAR (rSAR) and posterior portion of the SAR (pSAR) on CT scans, and the distance between the right lateral margin of the rSAR and the right lateral margin of the superior vena cava. Fluid collection in the rSAR on CT scans caused a right anterior mediastinal mass or a bulging contour on chest PA radiographs in all women patients. All patients showed cardiomegaly, five patients had pleural effusion, and two patients had mild pulmonary edema. Further, eight patients showed a connection between the rSAR and the pSAR. The characteristic features of these patients are the right anterior mediastinal mass-like opacity due to fluid collection in the rSAR, are bulging contour with a smooth margin and cardiomegaly regardless of pulmonary edema on the chest PA radiographs, and fluid connection between the rSAR and the pSAR on CT scans

  12. Fluid Collection in the Right Lateral Portion of the Superior Aortic Recess Mimicking a Right Mediastinal Mass: Assessment with Chest Posterior Anterior and MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Shn, Dong Rock; Ryu, Dae Shick; Park, Man Soo; Jung, Seung Mun; Ahn, Jae Hong; Lee, Jong Hyeog; Choi, Soo Jung [Dept. of Radiology, Gangneung Asan Hospital, College of Medicine, University of Ulsan, Gangneung (Korea, Republic of)

    2012-09-15

    We observed patients in whom the fluid collection in the right lateral portion of the superior aortic recess on computed tomography (CT) scans mimicked a right anterior mediastinal mass on chest PA radiographs. The purpose of this study was to assess chest PA and CT features of these patients. All chest PA radiographs and CT scans in 9 patients were reviewed by two radiologists on a consensus basis; for the presence of pleural effusion, pulmonary edema and heart size on chest PA radiographs. For the portion of the fluid collection in the superior aortic recess (SAR), a connection between the right lateral portion of the SAR (rSAR) and posterior portion of the SAR (pSAR) on CT scans, and the distance between the right lateral margin of the rSAR and the right lateral margin of the superior vena cava. Fluid collection in the rSAR on CT scans caused a right anterior mediastinal mass or a bulging contour on chest PA radiographs in all women patients. All patients showed cardiomegaly, five patients had pleural effusion, and two patients had mild pulmonary edema. Further, eight patients showed a connection between the rSAR and the pSAR. The characteristic features of these patients are the right anterior mediastinal mass-like opacity due to fluid collection in the rSAR, are bulging contour with a smooth margin and cardiomegaly regardless of pulmonary edema on the chest PA radiographs, and fluid connection between the rSAR and the pSAR on CT scans.

  13. Precision Strike Annual Programs Review

    Science.gov (United States)

    2009-03-11

    Damage Area*• GPS / INS Navigation + SAL Terminal • Precise əm CEP • Low Probability of Collateral Damage • GPS Extends Glide Range to 10+km • Agile...Page 311 Mar 09 Unclassified Unclassified Viper Strike Lineage Viper Strike SAL Seeker Proof of Principle Demos I & II Hunter-Viper Strike Quick...Information Management • CCA - Clinger Cohen Act • RIT- Rapid Improvement Team • BMMP – Business Management Modernization Program • BTA/ERAM – Business

  14. Coseismic conjugate faulting structures produced by the 2016 Mw 7.1 Kumamoto earthquake, Japan

    Science.gov (United States)

    Lin, Aiming; Chiba, Tatsuro

    2017-06-01

    Field investigations and analyses of airborne LiDAR data reveal that the 2016 Mw7.1 Kumamoto earthquake produced a ∼40-km-long surface rupture zone with a typical conjugate Riedel shearing fault structure along the pre-existing right-lateral strike-slip Hinagu-Futagawa Fault Zone (HFFZ). The conjugate Riedel shearing structure comprises two sets of coseismic shear fault zones that are oriented to NE-SW to ENE-WSW and WNW-ESE to E-W. The NE-SW to ENE-WSW-trending shear fault zone is characterized by R Riedel shear structures with right-lateral strike-slip displacement of up to 2.5 m, including left-stepping en echelon cracks (T-shear) and mole tracks (P-shear). In contrast, the WNW-ESE to E-W-trending shear fault zone is dominated by R‧ Riedel shear structures with left-lateral displacement of up to 1.3 m, including right-stepping en echelon tension cracks (T) and mole tracks (P), which are concentrated in a zone of strike-slip faults of HFFZ under the present E-W compressive stress in the study area, associated with the ongoing penetration of the Philippine Sea Plate into the Eurasian Plate.

  15. Using regional moment tensors to constrain the kinematics and stress evolution of the 2010–2013 Canterbury earthquake sequence, South Island, New Zealand

    Science.gov (United States)

    Herman, Matthew W.; Herrmann, Robert B.; Benz, Harley M.; Furlong, Kevin P.

    2014-01-01

    On September 3, 2010, a MW 7.0 (U.S. Geological Survey moment magnitude) earthquake ruptured across the Canterbury Plains in South Island, New Zealand. Since then, New Zealand GNS Science has recorded over 10,000 aftershocks ML 2.0 and larger, including three destructive ~ MW 6.0 earthquakes near Christchurch. We treat the Canterbury earthquake sequence as an intraplate earthquake sequence, and compare its kinematics to an Andersonian model for fault slip in a uniform stress field. We determined moment magnitudes and double couple solutions for 150 earthquakes having MW 3.7 and larger through the use of a waveform inversion technique using data from broadband seismic stations on South Island, New Zealand. The majority (126) of these double couple solutions have strike-slip focal mechanisms, with right-lateral slip on ENE fault planes or equivalently left-lateral slip on SSE fault planes. The remaining focal mechanisms indicate reverse faulting, except for two normal faulting events. The strike-slip segments have compatible orientations for slip in a stress field with a horizontal σ1 oriented ~ N115°E, and horizontal σ3. The preference for right lateral strike-slip earthquakes suggests that these structures are inherited from previous stages of deformation. Reverse slip is interpreted to have occurred on previously existing structures in regions with an absence of existing structures optimally oriented for strike-slip deformation. Despite the variations in slip direction and faulting style, most aftershocks had nearly the same P-axis orientation, consistent with the regional σ1. There is no evidence for significant changes in these stress orientations throughout the Canterbury earthquake sequence.

  16. Micro-seismicity and seismotectonic study in Western Himalaya-Ladakh-Karakoram using local broadband seismic data

    Science.gov (United States)

    Kanna, Nagaraju; Gupta, Sandeep; Prakasam, K. S.

    2018-02-01

    We document the seismic activity and fault plane solutions (FPSs) in the Western Himalaya, Ladakh and Karakoram using data from 16 broadband seismographs operated during June 2002 to December 2003. We locate 206 earthquakes with a local magnitude in the range of 1.5 to 4.9 and calculate FPSs of 19 selected earthquakes based on moment tensor solutions. The earthquakes are distributed throughout the study region and indicate active tectonics in this region. The observed seismicity pattern is quite different than a well-defined pattern of seismicity, along the Main Central Thrust zone, in the eastern side of the study region (i.e., Kumaon-Garhwal Himalaya). In the Himalaya region, the earthquakes are distributed in the crust and upper mantle, whereas in the Ladakh-Karakoram area the earthquakes are mostly confined up to crustal depths. The fault plane solutions show a mixture of thrust, normal and strike-slip type mechanisms, which are well corroborated with the known faults/tectonics of the region. The normal fault earthquakes are observed along the Southern Tibet Detachment, Zanskar Shear Zone, Tso-Morari dome, and Kaurik-Chango fault; and suggest E-W extension tectonics in the Higher and Tethys Himalaya. The earthquakes of thrust mechanism with the left-lateral strike-slip component are seen along the Kistwar fault. The right-lateral strike-slip faulting with thrust component along the bending of the Main Boundary Thrust and Main Central Thrust shows the transpressional tectonics in this part of the Himalaya. The observed earthquakes with right-lateral strike-slip faulting indicate seismically active nature of the Karakoram fault.

  17. Continental United States Hurricane Strikes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Continental U.S. Hurricane Strikes Poster is our most popular poster which is updated annually. The poster includes all hurricanes that affected the U.S. since...

  18. Evaluation of hypotheses for right-lateral displacement of Neogene strata along the San Andreas Fault between Parkfield and Maricopa, California

    Science.gov (United States)

    Stanley, Richard G.; Barron, John A.; Powell, Charles L.

    2017-12-22

    We used geological field studies and diatom biostratigraphy to test a published hypothesis that Neogene marine siliceous strata in the Maricopa and Parkfield areas, located on opposite sides of the San Andreas Fault, were formerly contiguous and then were displaced by about 80–130 kilometers (km) of right-lateral slip along the fault. In the Maricopa area on the northeast side of the San Andreas Fault, the upper Miocene Bitterwater Creek Shale consists of hard, siliceous shale with dolomitic concretions and turbidite sandstone interbeds. Diatom assemblages indicate that the Bitterwater Creek Shale was deposited about 8.0–6.7 million years before present (Ma) at the same time as the uppermost part of the Monterey Formation in parts of coastal California. In the Parkfield area on the southwest side of the San Andreas Fault, the upper Miocene Pancho Rico Formation consists of soft to indurated mudstone and siltstone and fossiliferous, bioturbated sandstone. Diatom assemblages from the Pancho Rico indicate deposition about 6.7–5.7 Ma (latest Miocene), younger than the Bitterwater Creek Shale and at about the same time as parts of the Sisquoc Formation and Purisima Formation in coastal California. Our results show that the Bitterwater Creek Shale and Pancho Rico Formation are lithologically unlike and of different ages and therefore do not constitute a cross-fault tie that can be used to estimate rightlateral displacement along the San Andreas Fault.In the Maricopa area northeast of the San Andreas Fault, the Bitterwater Creek Shale overlies conglomeratic fan-delta deposits of the upper Miocene Santa Margarita Formation, which in turn overlie siliceous shale of the Miocene Monterey Formation from which we obtained a diatom assemblage dated at about 10.0–9.3 Ma. Previous investigations noted that the Santa Margarita Formation in the Maricopa area contains granitic and metamorphic clasts derived from sources in the northern Gabilan Range, on the opposite side of

  19. Investigations on the aftershock sequence of the great Assam earthquake of August 15, 1950

    Directory of Open Access Journals (Sweden)

    V. K. GAUR

    1974-06-01

    Full Text Available The strain release curve of the aftershock sequence of the great Assam earthquake of August 15, 1950 exhibits three linear segments. A secondary aftershock sequence has also been reported; the strain release curve in this case is also linear. The b value, using the maximum likelihood method of Utsu, for the sequence is 0.52 ± 0.095. The fault plane solution shows that the fault strikes almost cast-west and dips northward at an angle of 80°; the motion is predominently strike slip (right lateral type. The spatial distribution of aftershocks shows two main centers of activity at the two ends of the probable fault.

  20. Cholelithiasis with atrophy of the right lateral hepatic lobe in a horse Colelitíase com atrofia do lobo lateral direito em um cavalo

    Directory of Open Access Journals (Sweden)

    Renato de Lima Santos

    2007-04-01

    Full Text Available A 22 year-old horse developed cholelithiasis with marked atrophy of the right lateral hepatic lobe. The horse had a history of intermittent colic since three years of age, and one of the first episodes of colic was associated with icterus. The size of the right lateral hepatic lobe was extremely reduced. There was a large choledocholith in the common hepatic duct, and several hepatoliths and choleliths in the intra- and extra-hepatic billiary ducts. Microscopically, there was severe atrophy of the right lobe with diffuse proliferation of connective tissue and billiary ducts. The left lateral lobe had peri-portal fibrosis with proliferation of billiary ducts, and billiary stasis. Chemical analysis of the calculi detected amorphous and triple phosphate, bilirubin, calcium, and iron.Um cavalo de 22 anos de idade desenvolveu quadro de colelitíase severa com atrofia do lobo lateral direito. O animal tinha histórico de cólica recorrente, desde os três anos de idade, sendo que um dos primeiros episódios de cólica foi acompanhado de icterícia. O lobo hepático lateral direito estava extremamente diminuído de volume. Havia um grande coledocólito localizado no ducto hepático comum e inúmeros hepatólitos e colélitos nos ductos biliares intra e extra-hepáticos. Microscopicamente, foi observada atrofia acentuada do lobo direito, com proliferação difusa de tecido conjuntivo fibroso e de ductos biliares. O lobo lateral esquerdo apresentava fibrose periportal difusa associada à proliferação acentuada de ductos biliares e estase biliar. Análise química das concreções detectou fosfato triplo e amorfo, bilirrubina, cálcio e ferro.

  1. [Physicians' strikes--ethical considerations].

    Science.gov (United States)

    Glick, Shimon; Schwarzfuchs, Dan

    2012-01-01

    Strikes in general represent a solution based on a form of coercion. Historically, the striker caused direct damage to his employer, who was responsible for the perceived unfair treatment of the employee. In the case of strikes in the public sector, the employer is generally not harmed, but innocent citizens suffer in order to pressure the government agencies, a questionable practice from an ethical viewpoint. Physicians' strikes have more serious ethical problems. They cause suffering and death to innocent citizens. They violate the ethical codes to which physicians have committed themselves as professionals, and they seriously impair the trust of the public in physicians. Better and more ethical ways to provide fair compensation for physicians must be employed, perhaps like those used for judges and members of the IDF.

  2. Incipient Evolution of the Eastern California Shear Zone through a Transpressional Zone along the San Andreas Fault in the San Bernardino Mountains, California

    Science.gov (United States)

    Cochran, W. J.; Spotila, J. A.

    2017-12-01

    Measuring long-term accumulation of strike-slip displacements and transpressional uplift is difficult where strain is accommodated across wide shear zones, as opposed to a single major fault. The Eastern California Shear Zone (ECSZ) in southern California accommodates dextral shear across several strike-slip faults, and is potentially migrating and cutting through a formerly convergent zone of the San Bernardino Mountains (SBM). The advection of crust along the San Andreas fault to the SE has forced these two tectonic regimes into creating a nexus of interacting strike-slip faults north of San Gorgonio Pass. These elements make this region ideal for studying complex fault interactions, evolving fault geometries, and deformational overprinting within a wide shear zone. Using high-resolution topography and field mapping, this study aims to test whether diffuse, poorly formed strike-slip faults within the uplifted SBM block are nascent elements of the ECSZ. Topographic resolution of ≤ 1m was achieved using both lidar and UAV surveys along two Quaternary strike-slip faults, namely the Lake Peak fault and Lone Valley faults. Although the Lone Valley fault cuts across Quaternary alluvium, the geomorphic expression is obscured, and may be the result of slow slip rates. In contrast, the Lake Peak fault is located high elevations north of San Gorgonio Peak in the SBM, and displaces Quaternary glacial deposits. The deposition of large boulders along the escarpment also obscures the apparent magnitude of slip along the fault. Although determining fault offset is difficult, the Lake Peak fault does display evidence for minor right-lateral displacement, where the magnitude of slip would be consistent with individual faults within the ECSZ (i.e. ≤ 1 mm/yr). Compared to the preservation of displacement along strike-slip faults located within the Mojave Desert, the upland region of the SBM adds complexity for measuring fault offset. The distribution of strain across the entire

  3. Respecting the right to strike

    CERN Multimedia

    Staff Association

    2015-01-01

    Since two years the representatives of the employers in the ILO, a tripartite multilateral body responsible for guaranteeing the correct application of an international labour code, try to weaken the global work regulations. On the occasion of the Global Day of Action for the right to strike at the invitation of the Geneva community of Union action (Communauté genevoise d’action syndicale) and the Swiss Trade Union Association (Union syndicale suisse) around noon on Wednesday 18th February some fifty staff representatives of international organizations gathered on the place des Nations in Geneva to reaffirm the importance of this fundamental right, too often flouted. A delegation of the CERN Staff Association was also present. In a short speech, the Staff Association said that, while being one of the fundamental human rights, to be efficient the right to strike must be used intelligently. It must be implemented taking into account the sensitivities of the professional environment and r...

  4. Tectonic implications of the 2017 Ayvacık (Çanakkale) earthquakes, Biga Peninsula, NW Turkey

    Science.gov (United States)

    Özden, Süha; Över, Semir; Poyraz, Selda Altuncu; Güneş, Yavuz; Pınar, Ali

    2018-04-01

    The west to southwestward motion of the Anatolian block results from the relative motions between the Eurasian, Arabian and African plates along the right-lateral North Anatolian Fault Zone in the north and left-lateral East Anatolian Fault Zone in the east. The Biga Peninsula is tectonically influenced by the Anatolian motion originating along the North Anatolian Fault Zone which splits into two main (northern and southern) branches in the east of Marmara region: the southern branch extends towards the Biga Peninsula which is characterized by strike-slip to oblique normal faulting stress regime in the central to northern part. The southernmost part of peninsula is characterized by a normal to oblique faulting stress regime. The analysis of both seismological and structural field data confirms the change of stress regime from strike-slip character in the center and north to normal faulting character in the south of peninsula where the earthquake swarm recently occurred. The earthquakes began on 14 January 2017 (Mw: 4.4) on Tuzla Fault and migrated southward along the Kocaköy and Babakale's stepped-normal faults of over three months. The inversion of focal mechanisms yields a normal faulting stress regime with an approximately N-S (N4°E) σ3 axis. The inversion of earthquakes occurring in central and northern Biga Peninsula and the north Aegean region gives a strike-slip stress regime with approximately WNW-ESE (N85°W) σ1 and NNE-SSW (N17°E) σ3 axis. The strike-slip stress regime is attributed to westward Anatolian motion, while the normal faulting stress regime is attributed to both the extrusion of Anatolian block and the slab-pull force of the subducting African plate along the Hellenic arc.

  5. Macular damage following lightning strikes.

    Science.gov (United States)

    Augustin, A J; Koch, F; Böker, T

    1995-07-01

    Two men with recent history of lightining strike were referred to our hospital. Both patients complained of metamorphosia in one eye and reduced visual acuity. Funduscopy revealed target-like alterations at the fovea. Fluorescein angiography showed window defects of the central retinal pigment epithelium in both patients. One patient developed an anterior subcapsular cataract. If the eye is part of the current-circuit, the melanin granules of the iris, pigment epithelium, and choroid might act as a resistor. The resulting accumulation of heat may lead to damage of the surrounding tissues.

  6. Women, transition and strikes in Serbia

    OpenAIRE

    Novaković, Nada G.

    2014-01-01

    The author, in a sociological way, describes and analyzes the concepts of transition, privatization and strikes in Serbia, particularly the place of women in it. It examines the most important economic and social causes and consequences of these phenomena. The main hypothesis is: women's strikes in the Serbian transition are less efficient than strikes and public protests of women in the developed world and the second Yugoslavia. A strike is a class conflict, in which the workers are fighting...

  7. 14 CFR 35.38 - Lightning strike.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Lightning strike. 35.38 Section 35.38... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by... lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller has...

  8. Strikes in Serbia since 2000 to 2005

    Directory of Open Access Journals (Sweden)

    Novaković Nada

    2005-01-01

    Full Text Available In this article author deals with main characteristics of strikes in Serbia within the period 2000–2005. Analysis starts with thesis that strike is open class conflict within class divided society. Therefore strike is radical form of trade union struggle for workers rights. Main questions in the analysis were: on social structure as a background of strikes, on organizations and trade unions included in it, on effects of strikes in Serbia in the given period. Main thesis of the article is that every power dislike strikes and is ready to do everything to diminish them. Main reason lies in the class nature of social conflict that underlie them. Main processes that underlie strike phenomena in Serbia since 2000. are the processes of originally capital accumulation. These bring about the formation of new capitalist class and proletariat of all professions. Author gives a brief analysis of privatization process, as well as of restructuring of public sector and deregulation of economy trying to show the role of all of it in origins of strikes. Main conclusion is that there are large number of strikes in all parts of society, that are well organized, with support of one or more trade unions. For these in power they are factor of obstacle on the way of successful transition. As for the reasons and outcomes these strikes are akin to the strikes at the beginning of 19th century.

  9. Third-party support for strike action.

    Science.gov (United States)

    Kelloway, E Kevin; Francis, Lori; Catano, Victor M; Dupré, Kathryne E

    2008-07-01

    Labor strikes are often seen as battles for public support. Members of the public are asked to show respect for a strike by refusing to cross the picket line or by joining strikers on the picket line. Such public support may affect the morale of strikers and influence the strike's duration. Despite the perceived importance of the public in labor disputes, members of third parties have not been considered in previous strike research. In 2 studies, the authors show that a new measure of third-party strike support is unidimensional and highly reliable. In both cases, union attitudes and perceptions of distributive justice were significant predictors of support for strike action. Those who are more supportive of unions in general and believe that the contract offered to the strikers was unfair were more likely to support the strike by engaging in such actions as conversing with strikers, writing letters, and refusing to cross the picket line.

  10. Recent paleoseismic investigations in Northern and Western Thailand

    Directory of Open Access Journals (Sweden)

    S. C. Wood

    2003-06-01

    Full Text Available Recent paleoseismic investigations have identified a number of active faults in Northern and Western Thailand. Northern Thailand is an intraplate basin and range province, comprised of north-south-trending Cenozoic intermontane grabens and half grabens, bounded by north- to northwest-striking normal to normal-oblique faults and northeast-striking left-lateral strike-slip faults. The basin-bounding normal faults are marked by steep, linear range fronts with triangular facets and wineglass canyons and have slip rates of 0.1 to 0.8 mm/yr. Based on limited data, the average vertical displacement-per-event is about 1.0 to 1.5 m. These faults are characterized by recurrence intervals of thousands to tens of thousands of years and are capable of generating earthquakes up to moment magnitude (M 7, and larger. The northeast-striking strike-slip faults are marked by shutter ridges, and deflected drainages. Slip rates are 3 mm/yr or less. Western Thailand is dissected by a number of northwest- and north-northwest-striking, right-lateral strike-slip faults related to the Sagaing Fault in Myanmar. Although showing much less activity than the faults in neighboring Myanmar, these faults display abundant evidence for late Quaternary movement, including shutter ridges, sag ponds, and laterally offset streams. The slip rate on these faults is estimated to be 0.5 to 2.0 mm/yr. These faults are considered capable of generating maximum earthquakes of up to M 71/2.

  11. Stress transfer to the Denali and other regional faults from the M 9.2 Alaska earthquake of 1964

    Science.gov (United States)

    Bufe, C.G.

    2004-01-01

    Stress transfer from the great 1964 Prince William Sound earthquake is modeled on the Denali fault, including the Denali-Totschunda fault segments that ruptured in 2002, and on other regional fault systems where M 7.5 and larger earthquakes have occurred since 1900. The results indicate that analysis of Coulomb stress transfer from the dominant earthquake in a region is a potentially powerful tool in assessing time-varying earthquake hazard. Modeled Coulomb stress increases on the northern Denali and Totschunda faults from the great 1964 earthquake coincide with zones that ruptured in the 2002 Denali fault earthquake, although stress on the Susitna Glacier thrust plane, where the 2002 event initiated, was decreased. A southeasterlytrending Coulomb stress transect along the right-lateral Totschunda-Fairweather-Queen Charlotte trend shows stress transfer from the 1964 event advancing slip on the Totschunda, Fairweather, and Queen Charlotte segments, including the southern Fairweather segment that ruptured in 1972. Stress transfer retarding right-lateral strike slip was observed from the southern part of the Totschunda fault to the northern end of the Fairweather fault (1958 rupture). This region encompasses a gap with shallow thrust faulting but with little evidence of strike-slip faulting connecting the segments to the northwest and southeast. Stress transfer toward failure was computed on the north-south trending right-lateral strike-slip faults in the Gulf of Alaska that ruptured in 1987 and 1988, with inhibitory stress changes at the northern end of the northernmost (1987) rupture. The northern Denali and Totschunda faults, including the zones that ruptured in the 2002 earthquakes, follow very closely (within 3%), for about 90??, an arc of a circle of radius 375 km. The center of this circle is within a few kilometers of the intersection at depth of the Patton Bay fault with the Alaskan megathrust. This inferred asperity edge may be the pole of counterclockwise

  12. Seismicity of the Earth 1900–2010 Himalaya and vicinity

    Science.gov (United States)

    Turner, Bethan; Jenkins, Jennifer; Turner, Rebecca; Parker, Amy; Sinclair, Alison; Davies, Sian; Hayes, Gavin P.; Villaseñor, Antonio; Dart, Rirchard L.; Tarr, Arthur C.; Furlong, Kevin P.; Benz, Harley M.

    2013-01-01

    Seismicity in the Himalaya region predominantly results from the collision of the India and Eurasia continental plates, which are converging at a relative rate of 40–50 mm/yr. Northward underthrusting of India beneath Eurasia generates numerous earthquakes and consequently makes this area one of the most seismically hazardous regions on Earth. The surface expression of the plate boundary is marked by the foothills of the north-south trending Sulaiman Range in the west, the Indo-Burmese Arc in the east, and the east-west trending Himalaya Front in the north of India. Along the western margin of the India plate, relative motions between India and Eurasia are accommodated by strike-slip, reverse, and oblique-slip faulting resulting in the complex Sulaiman Range fold and thrust belt, and the major translational Chaman Fault in Afghanistan. Beneath the Pamir‒Hindu Kush Mountains of northern Afghanistan, earthquakes occur to depths as great as 200 km as a result of remnant lithospheric subduction. Further north again, the Tian Shan is a seismically active intra-continental mountain belt defined by a series of east-west trending thrust faults thought to be related to the broad footprint of the India-Eurasia collision. Tectonics in northern India are dominated by motion along the Main Frontal Thrust and associated thrust faults of the India-Eurasia plate boundary, which have resulted in a series of large and devastating earthquakes in (and prior to) the 20th century. The Tibetan Plateau to the north of the main plate boundary is a broad region of uplift associated with the India-Eurasia collision, and is cut by a series of generally east-west trending strike-slip faults. These include the Kunlun, Haiyuan, and the Altyn Tagh faults, all of which are left-lateral structures, and the Kara-Koram right-lateral fault. Throughout the plateau, thrust faults accommodate the north-south compressional component of crustal shortening associated with the ongoing collision of India

  13. 14 CFR 29.631 - Bird strike.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird strike. 29.631 Section 29.631... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.631 Bird strike. The... safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of the...

  14. The role of E–W basement faults in the Mesozoic geodynamic ...

    Indian Academy of Sciences (India)

    Dorra Tanfous Amri

    2017-10-10

    Oct 10, 2017 ... and occurred only along main strike-slip faults. In addition, seismic lines show that Triassic rocks are .... ated anticlines are due to an E–W strike-slip fault, whereas Zargouni (1985), Boukadi (1994), Zouari ...... right–lateral oblique–slip features such as the Gafsa fault (Boukadi and Bédir 1996; Hlaiem 1999; ...

  15. Late Cretaceous evolution of the northern Sistan suture zone ...

    Indian Academy of Sciences (India)

    Demartis et al. 2011) and Africa (Ferre et al. 1995;. Cecys and Benn 2007; Vegas et al. 2008). ..... pressional and dextral strike-slip movement at least in the later episodes of intrusion, when magma was cooling. .... Internal fabric and strike-slip emplacement of the Pan-. African granite of Solli Hills, northern Nigeria; Tectonics.

  16. Lightning Strike in Pregnancy With Fetal Injury.

    Science.gov (United States)

    Galster, Kellen; Hodnick, Ryan; Berkeley, Ross P

    2016-06-01

    Injuries from lightning strikes are an infrequent occurrence, and are only rarely noted to involve pregnant victims. Only 13 cases of lightning strike in pregnancy have been previously described in the medical literature, along with 7 additional cases discovered within news media reports. This case report presents a novel case of lightning-associated injury in a patient in the third trimester of pregnancy, resulting in fetal ischemic brain injury and long-term morbidity, and reviews the mechanics of lightning strikes along with common injury patterns of which emergency providers should be aware. Copyright © 2016 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  17. 3-D structure of the crust and uppermost mantle at the junction between the Southeastern Alps and External Dinarides from ambient noise tomography

    Science.gov (United States)

    Guidarelli, Mariangela; Aoudia, Abdelkrim; Costa, Giovanni

    2017-12-01

    We use ambient noise tomography to investigate the crust and the uppermost mantle structure beneath the junction between the Southern Alps, the Dinarides and the Po Plain. We obtained Rayleigh wave empirical Green's functions from cross-correlation of vertical component seismic recordings for three years (2010-2012) using stations from networks in Italy, Slovenia, Austria, Croatia, Serbia and Switzerland. We measure group and phase velocity dispersion curves from the reconstructed Rayleigh waves in the period range 5-30 and 8-37 s, respectively, and we invert the surface wave velocities for tomographic images on a grid of 0.1° × 0.1°. After the tomography, the group velocities are then inverted to compute the 3-D shear wave velocity model of the crust and the upper mantle beneath the region. Our shear wave velocity model provides the 3-D image of the structure in the region between Northeastern Italy, Slovenia and Austria. The velocity variations at shallow depths correlate with known geological and tectonic domains. We find low velocities below the Po Plain, the northern tip of the Adriatic and the Pannonian Basin, whereas higher velocities characterize the Alpine chain. The vertical cross-sections reveal a clear northward increase of the crustal thickness with a sharp northward dipping of the Moho that coincides at the surface with the leading edge of the Alpine thrust front adjacent to the Friuli Plain in Northeastern Italy. This geometry of the Moho mimics fairly well the shallow north dipping geometry of the decollement inferred from permanent GPS velocity field where high interseismic coupling is reported. From the northern Adriatic domain up to the Idrija right lateral strike-slip fault system beneath Western Slovenia, the crustal thickness is more uniform. Right across Idrija fault, to the northeast, and along its strike, we report a clear change of the physical properties of the crust up to the uppermost mantle as reflected by the lateral distribution

  18. Tectonic evolution of the La González pull-apart basin in the Mérida Andes: combination of geological data and satellite radar interferometry (InSAR)

    Science.gov (United States)

    Javadi, Hamid Reza; Dehghani, Maryam; Foroutan, Mohammad; Naeimi, Amir; Roustaei, Mahasa; Saidi, Abdollah; Urbina, Josef Angel

    2016-07-01

    The 500-km-long Boconó strike-slip fault runs as a major active fault along the backbone of the Mérida Andes fold-and-thrust belt. The recent right-lateral motion on the fault led to formation of numerous structures such as pull-apart basins which have formed in releasing bends and/or right-step offsets along the fault strands. The La González pull-apart is the biggest basin generated as an extensional strike-slip duplex in the central part of the fault. This duplex is made up of two strands of the Boconó fault as master/first-order faults, while normal right-lateral faults which formed during evolution of the basin are second-order faults. The extension of the basin is associated with seismic activities and surface offsets along the Boconó fault. InSAR investigations over a 31-month period also support active deformation within the basin. These data indicate that the La González basin is continuously being extended as a result of motion along the Boconó fault and formation of subsequent normal faults. In addition, the basin is being transversely shortened in NW-SE direction due to regional shortening across the Mérida Andes range followed by convergence between the Maracaibo microplate and the Guyana shield.

  19. Expeditionary Strike Group: Command Structure Design Support

    National Research Council Canada - National Science Library

    Hutchins, Susan G; Kemple, William G; Kleinman, David L; Hocevar, Susan P

    2005-01-01

    An Expeditionary Strike Group (ESG) is a new capability mix that combines the combat power of three surface combatants and one submarine with an Amphibious Readiness Group/ Marine Expeditionary Unit...

  20. The Chicago Teachers Strike and Its Public

    Science.gov (United States)

    Shuffelton, Amy B.

    2014-01-01

    This article considers the 2012 Chicago Teachers Strike in light of John Dewey's "The Public and Its Problems." It engages Dewey's conceptualization of practical reason to challenge the educational reform movement's commitment to technocratic decision-making.

  1. Strikes in the public sector in Denmark

    DEFF Research Database (Denmark)

    Scheuer, Steen; Ibsen, Flemming; Høgedahl, Laust

    2016-01-01

    This article looks at strikes by employees in the public sector, discusses the theoretical background to these conflicts and shows – based on a case study of three strikes in the Danish public sector – how different union strategies lead to very different outcomes in terms of economic gains......, while public sector unions trying to move up the wage hierarchy cannot expect much help from fellow public sector unions, often quite the reverse....

  2. Scissoring Fault Rupture Properties along the Median Tectonic Line Fault Zone, Southwest Japan

    Science.gov (United States)

    Ikeda, M.; Nishizaka, N.; Onishi, K.; Sakamoto, J.; Takahashi, K.

    2017-12-01

    The Median Tectonic Line fault zone (hereinafter MTLFZ) is the longest and most active fault zone in Japan. The MTLFZ is a 400-km-long trench parallel right-lateral strike-slip fault accommodating lateral slip components of the Philippine Sea plate oblique subduction beneath the Eurasian plate [Fitch, 1972; Yeats, 1996]. Complex fault geometry evolves along the MTLFZ. The geomorphic and geological characteristics show a remarkable change through the MTLFZ. Extensional step-overs and pull-apart basins and a pop-up structure develop in western and eastern parts of the MTLFZ, respectively. It is like a "scissoring fault properties". We can point out two main factors to form scissoring fault properties along the MTLFZ. One is a regional stress condition, and another is a preexisting fault. The direction of σ1 anticlockwise rotate from N170°E [Famin et al., 2014] in the eastern Shikoku to Kinki areas and N100°E [Research Group for Crustral Stress in Western Japan, 1980] in central Shikoku to N85°E [Onishi et al., 2016] in western Shikoku. According to the rotation of principal stress directions, the western and eastern parts of the MTLFZ are to be a transtension and compression regime, respectively. The MTLFZ formed as a terrain boundary at Cretaceous, and has evolved with a long active history. The fault style has changed variously, such as left-lateral, thrust, normal and right-lateral. Under the structural condition of a preexisting fault being, the rupture does not completely conform to Anderson's theory for a newly formed fault, as the theory would require either purely dip-slip motion on the 45° dipping fault or strike-slip motion on a vertical fault. The fault rupture of the 2013 Barochistan earthquake in Pakistan is a rare example of large strike-slip reactivation on a relatively low angle dipping fault (thrust fault), though many strike-slip faults have vertical plane generally [Avouac et al., 2014]. In this presentation, we, firstly, show deep subsurface

  3. Deformed Fluvial Terraces of Little Rock Creek Capture Off-Fault Strain Adjacent to the Mojave Section of the San Andreas Fault

    Science.gov (United States)

    Moulin, A.; Scharer, K. M.; Cowgill, E.

    2017-12-01

    Examining discrepancies between geodetic and geomorphic slip-rates along major strike-slip faults is essential for understanding both fault behavior and seismic hazard. Recent work on major strike-slip faults has highlighted off-fault deformation and its potential impact on fault slip rates. However, the extent of off-fault deformation along the San Andreas Fault (SAF) remains largely uncharacterized. Along the Mojave section of the SAF, Little Rock Creek drains from south to north across the fault and has cut into alluvial terraces abandoned between 15 and 30 ka1. The surfaces offer a rare opportunity to both characterize how right-lateral slip has accumulated along the SAF over hundreds of seismic cycles, and investigate potential off-fault deformation along secondary structures, where strain accumulates at slower rates. Here we use both field observations and DEM analysis of B4 lidar data to map alluvial and tectonic features, including 9 terrace treads that stand up to 80 m above the modern channel. We interpret the abandonment and preservation of the fluvial terraces to result from episodic capture of Little Rock Creek through gaps in a shutter ridge north of the fault, followed by progressive right deflection of the river course during dextral slip along the SAF. Piercing lines defined by fluvial terrace risers suggest that the amount of right slip since riser formation ranges from 400m for the 15-ka-riser to 1200m for the 30-ka-riser. Where they are best-preserved NE of the SAF, terraces are also cut by NE-facing scarps that trend parallel to the SAF in a zone extending up to 2km from the main fault. Exposures indicate these are fault scarps, with both reverse and normal stratigraphic separation. Geomorphic mapping reveals deflections of both channel and terrace risers (up to 20m) along some of those faults suggesting they could have accommodated a component of right-lateral slip. We estimated the maximum total amount of strike-slip motion recorded by the

  4. Geological structures deduced from airborne geophysical surveys around Syowa Station, Antarctica

    Science.gov (United States)

    Nogi, Y.; Jokat, W.; Kitada, K.; Steinhage, D.

    2012-12-01

    The area around Syowa Station, the Japanese Antarctic station in Lutzow-Holm Bay, is widely considered to be a junction of the Africa, India, Madagascar, and Antarctic continents, according to the reconstruction model of Gondwana. This area is key to investigating the formation of Gondwana. Joint Japanese-German airborne geophysical surveys were conducted around Syowa Station in January 2006 to reveal the tectonic evolution contributing to the formation of Gondwana in this area. Ice radar, magnetic, and gravity data were obtained from onshore areas. Several characteristic features that may be related to the tectonic evolution of Gondwana were inferred primarily from magnetic anomalies and from gravity anomalies and bedrock topography. The boundaries of the Lutzow-Holm Complex, the Yamato-Belgica Complex, and the Western Rayner Complex are defined, but the inland extension of the boundary between the Lutzow-Holm and the Yamato-Belgica Complexes is unknown south of 71S. The main geological structural trends of the Lutzow-Holm Complex derived from magnetic anomalies are NW-SE and are concordant with the geological results in the coastal region. However, nearly NE-SW-trending magnetic anomalies cut across the NW-SW magnetic anomaly trends, and the NE-SW right lateral strike-slip faults are deduced from the magnetic and the gravity anomaly data in the Lutzow-Holm Complex. The Lutzow-Holm Complex is divided into four blocks based on the estimated strike-slip faults. The strike-slip faults were possibly generated during a younger stage of Pan-African orogeny, after the formation of NW-SE-striking geological structures. These results provide new constraints for the formation of Gondwana.

  5. Women, transition and strikes in Serbia

    Directory of Open Access Journals (Sweden)

    Novaković Nada G.

    2014-01-01

    Full Text Available The author, in a sociological way, describes and analyzes the concepts of transition, privatization and strikes in Serbia, particularly the place of women in it. It examines the most important economic and social causes and consequences of these phenomena. The main hypothesis is: women's strikes in the Serbian transition are less efficient than strikes and public protests of women in the developed world and the second Yugoslavia. A strike is a class conflict, in which the workers are fighting for their social and economic rights, threatened by the capitalist class. Elites in government and state authorities protect the interests of big capital at the detriment of the interests of the majority of workers. Exploring women's strikes in transition reveals the nature of the social and political system. Their strikes in enterprises, the blocking of public spaces and public protests are systemic, ie. class determined. As the transition was very fast, the resistance of the strikers was inefficient, and the protests of women became an expression of desperation against the loss of jobs and basic resources for lifehood. In short, this research is about the main causes, the organizational forms and the consequences of strikes in which the majority were women. For this purpose, the author chose to describe an array of strikes in the industries and the companies where women are most employed. The choice of strikes in the economic sector is not accidental, but a consequence of the fact that the women there were the most vulnerable. Women in public institutions and companies had much higher financial and social position. They are less likely to strike and publicly protested. After 2000, these strikes were more successful than worker's strikes in textile, food processing, manufacturing and trade. Relationship between the government and the public towards them was tainted by self-interest and selective. The main criterion for the selection of companies and

  6. Growth and linkage of the quaternary Ubrique Normal Fault Zone, Western Gibraltar Arc: role on the along-strike relief segmentation

    Science.gov (United States)

    Jiménez-Bonilla, Alejandro; Balanya, Juan Carlos; Exposito, Inmaculada; Diaz-Azpiroz, Manuel; Barcos, Leticia

    2015-04-01

    pattern seems to be related to other strike-slip fault systems developed to the E of the UNFZ. The structural revision together with updated kinematic data suggest that the Colmenar Fault is cut and downthrown by a younger normal fault zone, the UNFZ, which would have contributed to accommodate arc-parallel stretching until the Quaternary. This stretching provokes along-strike relief segmentation, being the UNFZ the main fault zone causing the final drop of the Subbetic ranges towards the SW within the Western Gibraltar Arc. Our results show displacement variations in each fault segment of the UNFZ, diminishing to their tips. This suggests fault segment linkage finally evolved to build the nearly continuous current fault zone. The development of current large through-going faults linked inside the UNFZ is similar to those ones simulated in some numerical modelling of rift systems [2]. Acknowledgements: RNM-415 and CGL-2013-46368-P [1]Peacock, D.C.P., Knipe, R.J., Sanderson, D.J., 2000. Glossary of normal faults. Journal Structural Geology, 22, 291-305. [2]Cowie, P.A., Gupta, S., Dawers, N.H., 2000. Implications of fault array evolution for synrift depocentre development: insights from a numerical fault growth model. Basin Research, 12, 241-261.

  7. ELMs, strike point jumps and SOL currents

    International Nuclear Information System (INIS)

    Solano, Emilia R.; Jachmich, S.; Villone, F.; Hawkes, N.; Guenther, K.; Korotkov, A.; Stamp, M.; Andrew, P.; Conboy, J.; Mattews, G.F.; Corre, Y.; Loarte, A.; Pitts, R.A.; Cenedese, A.; Kempenaars, M.; Bolzonella, T.; Rachlew, E.

    2005-01-01

    Plasma equilibria before and after ELMs in JET are investigated. ELMs could be associated with fragile equilibria and separatrix instabilities: previously closed field lines would open up, releasing plasma current and leading to the formation of a new, smaller separatrix. This model could explain experimental observations of sudden jumps and shifts in strike point positions. Novel instability mechanisms are discussed to explain the large transient jumps observed in the strike point position: positive X-point instability, due to positive toroidal current density at the X-point and diamagnetic instability, due to negative inboard toroidal current density. (author)

  8. Strikes, solidarity and scabs. Union members participation norms and williengness to participate in strikes.

    NARCIS (Netherlands)

    Akkerman, A.; Born, M.; Torenvlied, R.

    2013-01-01

    This article studies how participation norms affect workers' willingness to strike. A factor analysis on the responses of 468 Dutch union members about appropriate behavior during a strike produces two factors. The first factor reflects a "solidarity norm" favoring group solidarity; the second

  9. Simulating the Risk of Bird Strikes

    NARCIS (Netherlands)

    Metz, I.C.; Ellerbroek, J.; Muhlhausen, Thorsten; Kügler, D.; Hoekstra, J.M.

    2017-01-01

    This paper presents a fast-time simulation environment for assessing the risk of bird strikes in aviation. An existing air traffic simulator was enhanced in order to simulate air and bird traffic simultaneously and to recognize collisions between birds and aircraft. Furthermore, a method was

  10. The Front Line: No Strikes, Just Balls.

    Science.gov (United States)

    Unks, Gerald

    1979-01-01

    Recent actions of British teachers suggest an alternative to the teacher strike. Those teachers dramatically demonstrated their grievances by withholding the voluntary extra services they customarily perform. American teachers could accomplish the same end by collectively refusing to perform extraneous administrative services: collecting money,…

  11. When Lightning Strikes a Second Time

    Science.gov (United States)

    Allen, Kent

    2017-01-01

    The chances of lightning striking twice are infinitesimal, at best. What are the odds, in middle age, of being struck with a jarring bolt of figurative lightning, then a few months later being an eyewitness as the same sizzle in the sky jolts a group of students--those decision-makers of tomorrow? The author describes two experiences that proved…

  12. Impact of lightning strikes on hospital functions.

    Science.gov (United States)

    Mortelmans, Luc J M; Van Springel, Gert L J; Van Boxstael, Sam; Herrijgers, Jan; Hoflacks, Stefaan

    2009-01-01

    Two regional hospitals were struck by lightning during a one-month period. The first hospital, which had 236 beds, suffered a direct strike to the building. This resulted in a direct spread of the power peak and temporary failure of the standard power supply. The principle problems, after restoring standard power supply, were with the fire alarm system and peripheral network connections in the digital radiology systems. No direct impact on the hardware could be found. Restarting the servers resolved all problems. The second hospital, which had 436 beds, had a lightning strike on the premises and mainly experienced problems due to induction. All affected installations had a cable connection from outside in one way or another. The power supplies never were endangered. The main problem was the failure of different communication systems (telephone, radio, intercom, fire alarm system). Also, the electronic entrance control went out. During the days after the lightening strike, multiple software problems became apparent, as well as failures of the network connections controlling the technical support systems. There are very few ways to prepare for induction problems. The use of fiber-optic networks can limit damage. To the knowledge of the authors, these are the first cases of lightning striking hospitals in medical literature.

  13. [Management of the hunger strike in prison].

    Science.gov (United States)

    Fayeulle, Stéphanie; Renou, Frédéric; Protais, Emmanuel; Hédouin, Valéry; Wartel, Guillaume; Yvin, Jean-Luc

    2010-10-01

    Entering prison can feed pre-existent behavior of demands or generate them. Several means of expression are then used. Hunger strike is an average privileged act. It belongs to prison culture. Estimate how practitioners working in prison take care of the hunger strikers. The study, realised in 2008, was led with all the Units of Consultations and Ambulatory Care in France. It is a declarative investigation where a medical testimony by unit was asked. From 174 "maisons d'arrêt" and establishments for punishment in France, 95 answers were obtained. This situation was already seen by 98,8% of the doctors. The motives for hunger strike were mainly judicial for "maisons d'arrêt" (70,1%) and prison motives for detention centers (68,7%). Mainly, doctors opted for a neutral attitude (63% of the cases). The hunger strikes were mostly brief (less than a week in 85% of the cases). Only 5,5% of the doctors proposed written information concerning the risks incurred during a fast. A doctor in 4 approximately (23%) was already witness to complications due to fasting. The fact that a patient may refuse care makes the medical approach difficult. Faced with such a situation, 45% of the doctors privileged their duty of care, 28% respected the patient's wishes, and 27% did not pronounce. From a therapeutic point of view, the place of treatment using vitamins was rarely recognized (32,7%). Hunger strike is rarely severe, but it is rather frequent in prison so that every doctor working there will be confronted with it. The refeeding syndrome seems often ignored. The coverage of hunger strike is governed by the law, but ethical questions stay in the appreciation of every doctor. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  14. Identification of Lembang fault, West-Java Indonesia by using controlled source audio-magnetotelluric (CSAMT)

    Science.gov (United States)

    Sanny, Teuku A.

    2017-07-01

    The objective of this study is to determine boundary and how to know surrounding area between Lembang Fault and Cimandiri fault. For the detailed study we used three methodologies: (1). Surface deformation modeling by using Boundary Element method and (2) Controlled Source Audiomagneto Telluric (CSAMT). Based on the study by using surface deformation by using Boundary Element Methods (BEM), the direction Lembang fault has a dominant displacement in east direction. The eastward displacement at the nothern fault block is smaller than the eastward displacement at the southern fault block which indicates that each fault block move in left direction relative to each other. From this study we know that Lembang fault in this area has left lateral strike slip component. The western part of the Lembang fault move in west direction different from the eastern part that moves in east direction. Stress distribution map of Lembang fault shows difference between the eastern and western segments of Lembang fault. Displacement distribution map along x-direction and y-direction of Lembang fault shows a linement oriented in northeast-southwest direction right on Tangkuban Perahu Mountain. Displacement pattern of Cimandiri fault indicates that the Cimandiri fault is devided into two segment. Eastern segment has left lateral strike slip component while the western segment has right lateral strike slip component. Based on the displacement distribution map along y-direction, a linement oriented in northwest-southeast direction is observed at the western segment of the Cimandiri fault. The displacement along x-direction and y-direction between the Lembang and Cimandiri fault is nearly equal to zero indicating that the Lembang fault and Cimandiri Fault are not connected to each others. Based on refraction seismic tomography that we know the characteristic of Cimandiri fault as normal fault. Based on CSAMT method th e lembang fault is normal fault that different of dip which formed as

  15. Late Palaeozoic to Triassic evolution of the Turan and Scythian platforms: The pre-history of the Palaeo-Tethyan closure

    Science.gov (United States)

    Natal'in, Boris A.; Şengör, A. M. Celâl

    2005-08-01

    A number of en échelon-arranged, southwest-facing arc fragments of Palaeozoic to Jurassic ages, sandwiched between two fairly straight east-northeast trending boundaries, constitute the basement of the Scythian and the Turan platforms located between the Laurasian and Tethyside units. They have until now largely escaped detection owing to extensive Jurassic and younger cover and the inaccessibility of the subsurface data to the international geological community. These units are separated from one another by linear/gently-curved faults of great length and steep dip. Those that are exposed show evidence of strike-slip motion. The arc units originally constituted parts of a single "Silk Road Arc" located somewhere south of the present-day central Asia for much of the Palaeozoic, although by the late Carboniferous they had been united into a continental margin arc south of the Tarim basin and equivalent units to the west and east. They were stacked into their present places in northern Afghanistan, Turkmenistan, Caucasus and the northern Black Sea by large-scale, right-lateral strike-slip coastwise transport along arc-slicing and arc-shaving strike-slip faults in the Triassic and medial Jurassic simultaneously with the subductive elimination of Palaeo-Tethys. This gigantic dextral zone ("the Silk Road transpression") was a trans-Eurasian structure and was active simultaneously with another, similar system, the Gornostaev keirogen and greatly distorted Eurasia. The late Palaeozoic to Jurassic internal deformation of the Dniepr-Donets aulacogen was also a part of the dextral strain in southern Europe. When the emplacement of the Scythian and Turan units was completed, the elimination of Palaeo-Tethys had also ended and Neo-Tethyan arcs were constructed atop their ruins, mostly across their southern parts. The western end of the great dextral zone that emplaced the Turan and Scythian units horsetails just east of north Dobrudja and a small component goes along the

  16. Gait Retraining From Rearfoot Strike to Forefoot Strike does not change Running Economy.

    Science.gov (United States)

    Roper, Jenevieve Lynn; Doerfler, Deborah; Kravitz, Len; Dufek, Janet S; Mermier, Christine

    2017-12-01

    Gait retraining is a method for management of patellofemoral pain, which is a common ailment among recreational runners. The present study investigated the effects of gait retraining from rearfoot strike to forefoot strike on running economy, heart rate, and respiratory exchange ratio immediately post-retraining and one-month post-retraining in recreational runners with patellofemoral pain. Knee pain was also measured. Sixteen participants (n=16) were randomly placed in the control (n=8) or experimental (n=8) group. A 10-minute treadmill RE test was performed by all subjects. The experimental group performed eight gait retraining running sessions where foot strike pattern was switched from rearfoot strike to forefoot strike, while the control group received no intervention. There were no significant differences for running economy (p=0.26), respiratory exchange ratio (p=0.258), or heart rate (p=0.248) between the groups. Knee pain reported on a visual analog scale was also significantly reduced (p<0.05) as a result of retraining. The present study demonstrates that retraining from rearfoot strike to forefoot strike did not affect running economy up to one-month post-retraining while reducing running-related patellofemoral pain. © Georg Thieme Verlag KG Stuttgart · New York.

  17. ["Bell-striking" Saying of Acupuncture Therapy].

    Science.gov (United States)

    Zhao, Jing-Sheng

    2017-04-25

    As an analogy, a prototype of "bell-striking" is proposed in the present paper for exploring the basic properties, major elements, and potential mechanisms of acupuncture stimulation. On the strength of analysis on the physiological basis of acupuncture effect, several fundamental aspects of acupuncture are summarized as a) the body-surface stimulating characters, b) general and local effects, and c) triggering the auto-regulative function of the organism, which mimics the "bell-striking" response. Namely, when stroke, bell will chime, otherwise, chiming will not be heard. During analyzing special contents of acupuncture theory, its formative background should not be separated, and it is improper to take, modern medical theory of the human body as the guiding thinking way for researching the ancient Chinese medical literature.

  18. Central hyperadrenergic state after lightning strike.

    Science.gov (United States)

    Parsaik, Ajay K; Ahlskog, J Eric; Singer, Wolfgang; Gelfman, Russell; Sheldon, Seth H; Seime, Richard J; Craft, Jennifer M; Staab, Jeffrey P; Kantor, Birgit; Low, Phillip A

    2013-08-01

    To describe and review autonomic complications of lightning strike. Case report and laboratory data including autonomic function tests in a subject who was struck by lightning. A 24-year-old man was struck by lightning. Following that, he developed dysautonomia, with persistent inappropriate sinus tachycardia and autonomic storms, as well as posttraumatic stress disorder (PTSD) and functional neurologic problems. The combination of persistent sinus tachycardia and episodic exacerbations associated with hypertension, diaphoresis, and agitation was highly suggestive of a central hyperadrenergic state with superimposed autonomic storms. Whether the additional PTSD and functional neurologic deficits were due to a direct effect of the lightning strike on the central nervous system or a secondary response is open to speculation.

  19. The October 28, 2012 Mw 7.8 Haida Gwaii underthrusting earthquake and tsunami: Slip partitioning along the Queen Charlotte Fault transpressional plate boundary

    Science.gov (United States)

    Lay, Thorne; Ye, Lingling; Kanamori, Hiroo; Yamazaki, Yoshiki; Cheung, Kwok Fai; Kwong, Kevin; Koper, Keith D.

    2013-08-01

    The Pacific/North American plate boundary is undergoing predominantly right-lateral strike-slip motion along the Queen Charlotte and Fairweather transform faults. The Queen Charlotte Fault (QCF) hosted the largest historical earthquake in Canada, the 1949 MS 8.1 strike-slip earthquake, which ruptured from offshore northern Haida Gwaii several hundred kilometers northwestward. On January 5, 2013 an Mw 7.5 strike-slip faulting event occurred near the northern end of the 1949 rupture zone. Along central and southern Haida Gwaii the relative plate motion has ∼20% oblique convergence across the left-stepping plate boundary. There had been uncertainty in how the compressional component of plate motion is accommodated. The October 28, 2012 Mw 7.8 Haida Gwaii earthquake involved slightly (∼20°) oblique thrust faulting on a shallow (∼18.5°) northeast-dipping fault plane with strike (∼320°) parallel to the QCF, consistent with prior inferences of Pacific Plate underthrusting beneath Haida Gwaii. The rupture extended to shallow depth offshore of Moresby Island beneath a 25-30 km wide terrace of sediments that has accumulated in a wedge seaward of the QCF. The shallow thrusting caused seafloor uplift that generated substantial localized tsunami run-up and a modest far-field tsunami that spread across the northern Pacific, prompting a tsunami warning, beach closure, and coastal evacuation in Hawaii, although ultimately tide gauges showed less than 0.8 m of water level increase. The mainshock rupture appears to have spread with a ∼2.3 km/s rupture velocity over a length of ∼150 km, with slip averaging 3.3 m concentrated beneath the sedimentary wedge. The event was followed by a substantial aftershock sequence, in which almost all of the larger events involve distributed intraplate normal faulting extending ∼50 km oceanward from the QCF. The highly oblique slip partitioning in southern Haida Gwaii is distinctive in that the local plate boundary-parallel motion on

  20. Improving work conditions through strike: Examination of nurses' attitudes through perceptions of two physician strikes in Israel.

    Science.gov (United States)

    Gafni-Lachter, Liat; Admi, Hanna; Eilon, Yael; Lachter, Jesse

    2017-01-01

    Strikes are means to influence policies related to working conditions, yet raise ethical dilemmas for healthcare workers. Nurse strikes have become more prominent around the world. To assess the change in Israeli nurses' attitudes towards strikes in light of two physician strikes that have preceded a nursing strike. An anonymous survey was administered once in 2000 (N = 106) and again in 2011 (n = 175) following 110 days of a physician strike, to assess nurses' attitudes towards the strike and resulting ethical issues. A statistically significant change (p working conditions related to professional and public health agendas.

  1. Stress distribution of metatarsals during forefoot strike versus rearfoot strike: A finite element study.

    Science.gov (United States)

    Li, Shudong; Zhang, Yan; Gu, Yaodong; Ren, James

    2017-12-01

    Due to the limitations of experimental approaches, comparison of the internal deformation and stresses of the human man foot between forefoot and rearfoot landing is not fully established. The objective of this work is to develop an effective FE modelling approach to comparatively study the stresses and energy in the foot during forefoot strike (FS) and rearfoot strike (RS). The stress level and rate of stress increase in the Metatarsals are established and the injury risk between these two landing styles is evaluated and discussed. A detailed subject specific FE foot model is developed and validated. A hexahedral dominated meshing scheme was applied on the surface of the foot bones and skin. An explicit solver (Abaqus/Explicit) was used to stimulate the transient landing process. The deformation and internal energy of the foot and stresses in the metatarsals are comparatively investigated. The results for forefoot strike tests showed an overall higher average stress level in the metatarsals during the entire landing cycle than that for rearfoot strike. The increase rate of the metatarsal stress from the 0.5 body weight (BW) to 2 BW load point is 30.76% for forefoot strike and 21.39% for rearfoot strike. The maximum rate of stress increase among the five metatarsals is observed on the 1st metatarsal in both landing modes. The results indicate that high stress level during forefoot landing phase may increase potential of metatarsal injuries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. FOP 2012 stop, Honey Lake fault, Doyle, CA

    Science.gov (United States)

    Gold, Ryan; Briggs, Richard W.; Crone, Anthony; Angster, Steve; Seitz, Gordon G.

    2012-01-01

    The Honey Lake fault system (HLFS) strikes north-northwestward across Long Valley near Doyle, CA and is part of a network of active, dextral strike-slip faults in the northern Walker Lane (Figure 1). Geologic investigations of a right-laterally offset terrace riser along the north bank of Long Valley Creek, which we refer to as site 1 (Figure 2), indicate a latest Quaternary slip rate of 1.1-2. 6 mm/yr [Wills and Borchardt, 1993] and 1.7 ± 0.6 mm/yr [Turner and others, 2008] (Table 1). These studies also document evidence of at least four post-6.8 ka surface-rupturing earthquakes at this site.

  3. New evidence on the state of stress of the san andreas fault system.

    Science.gov (United States)

    Zoback, M D; Zoback, M L; Mount, V S; Suppe, J; Eaton, J P; Healy, J H; Oppenheimer, D; Reasenberg, P; Jones, L; Raleigh, C B; Wong, I G; Scotti, O; Wentworth, C

    1987-11-20

    Contemporary in situ tectonic stress indicators along the San Andreas fault system in central California show northeast-directed horizontal compression that is nearly perpendicular to the strike of the fault. Such compression explains recent uplift of the Coast Ranges and the numerous active reverse faults and folds that trend nearly parallel to the San Andreas and that are otherwise unexplainable in terms of strike-slip deformation. Fault-normal crustal compression in central California is proposed to result from the extremely low shear strength of the San Andreas and the slightly convergent relative motion between the Pacific and North American plates. Preliminary in situ stress data from the Cajon Pass scientific drill hole (located 3.6 kilometers northeast of the San Andreas in southern California near San Bernardino, California) are also consistent with a weak fault, as they show no right-lateral shear stress at approximately 2-kilometer depth on planes parallel to the San Andreas fault.

  4. The 2016 Kumamoto earthquake sequence.

    Science.gov (United States)

    Kato, Aitaro; Nakamura, Kouji; Hiyama, Yohei

    2016-01-01

    Beginning in April 2016, a series of shallow, moderate to large earthquakes with associated strong aftershocks struck the Kumamoto area of Kyushu, SW Japan. An M j 7.3 mainshock occurred on 16 April 2016, close to the epicenter of an M j 6.5 foreshock that occurred about 28 hours earlier. The intense seismicity released the accumulated elastic energy by right-lateral strike slip, mainly along two known, active faults. The mainshock rupture propagated along multiple fault segments with different geometries. The faulting style is reasonably consistent with regional deformation observed on geologic timescales and with the stress field estimated from seismic observations. One striking feature of this sequence is intense seismic activity, including a dynamically triggered earthquake in the Oita region. Following the mainshock rupture, postseismic deformation has been observed, as well as expansion of the seismicity front toward the southwest and northwest.

  5. The 2016 Kumamoto earthquake sequence

    Science.gov (United States)

    KATO, Aitaro; NAKAMURA, Kouji; HIYAMA, Yohei

    2016-01-01

    Beginning in April 2016, a series of shallow, moderate to large earthquakes with associated strong aftershocks struck the Kumamoto area of Kyushu, SW Japan. An Mj 7.3 mainshock occurred on 16 April 2016, close to the epicenter of an Mj 6.5 foreshock that occurred about 28 hours earlier. The intense seismicity released the accumulated elastic energy by right-lateral strike slip, mainly along two known, active faults. The mainshock rupture propagated along multiple fault segments with different geometries. The faulting style is reasonably consistent with regional deformation observed on geologic timescales and with the stress field estimated from seismic observations. One striking feature of this sequence is intense seismic activity, including a dynamically triggered earthquake in the Oita region. Following the mainshock rupture, postseismic deformation has been observed, as well as expansion of the seismicity front toward the southwest and northwest. PMID:27725474

  6. Acute transient hemiparesis induced by lightning strike.

    Science.gov (United States)

    Rahmani, Seyed Hesam; Faridaalaee, Gholamreza; Jahangard, Samira

    2015-07-01

    According to data from the National Oceanic and Atmospheric Administration,in the years from 1959 to 1994, lightning was responsible for more than 3000 deaths and nearly 10,000 casualties. The most important characteristic features of lightning injuries are multisystem involvement and widely variable severity. Lightning strikes are primarily a neurologic injury that affects all 3 components of the nervous system: central, autonomic,and peripheral. Neurologic complications of lightning strikes vary from transient benign symptoms to permanent disability. Many patients experience a temporary paralysis called keraunoparalysis. Here we reported a 22-year-old mountaineer man with complaining of left sided hemiparesis after being hit by a lightning strike in the mountain 3 hours ago. There was no loss of consciousness at hitting time. On arrival the patient was alert, awake and hemodynamically stable. In neurologic examination cranial nerves were intact, left sided upper and lower extremity muscle force was I/V with a combination of complete sensory loss, and right-sided muscle force and sensory examination were normal. There is not any evidence of significant vascular impairment in the affected extremities. Brain MRI and CT scan and cervical MRI were normal. During 2 days of admission, with intravenous hydration, heparin 5000 unit SC q12hr and physical therapy of the affected limbs, motor and sensory function improved and was normal except mild paresthesia. He was discharged 1 day later for outpatient follow up while vitamin B1 100mg orally was prescribed.Paresthesia improved after 3 days without further sequels.

  7. Evolution of the stress fields in the Zagros Foreland Folded Belt using focal mechanisms and kinematic analyses: the case of the Fars salient, Iran

    Science.gov (United States)

    Sarkarinejad, Khalil; Zafarmand, Bahareh; Oveisi, Behnam

    2018-03-01

    The NW-SE trending Zagros orogenic belt was initiated during the convergence of the Afro-Arabian continent and the Iranian microcontinent in the Late Cretaceous. Ongoing convergence is confirmed by intense seismicity related to compressional stresses collision-related in the Zagros orogenic belt by reactivation of an early extensional faulting to latter compressional segmented strike-slip and dip-slip faulting. These activities are strongly related either to the deep-seated basement fault activities (deep-seated earthquakes) underlies the sedimentary cover or gently dipping shallow-seated décollement horizon of the rheological weak rocks of the infra-Cambrian Hormuz salt. The compressional stress regimes in the different units play an important role in controlling the stress conditions between the different units within the sedimentary cover and basement. A significant set of nearly N-S trending right-lateral strike-slip faults exists throughout the study area in the Fars area in the Zagros Foreland Folded Belt. Fault-slip and focal mechanism data were analyzed using the stress inversion method to reconstruct the paleo and recent stress conditions. The results suggest that the current direction of maximum principal stress averages N19°E, with N38°E that for the past from Cretaceous to Tertiary (although a few sites on the Kar-e-Bass fault yield a different direction). The results are consistent with the collision of the Afro-Arabian continent and the Iranian microcontinent. The difference between the current and paleo-stress directions indicates an anticlockwise rotation in the maximum principle stress direction over time. This difference resulted from changes in the continental convergence path, but was also influenced by the local structural evolution, including the lateral propagation of folds and the presence of several local décollement horizons that facilitated decoupling of the deformation between the basement and the sedimentary cover. The obliquity of

  8. Lightning strike-induced brachial plexopathy

    Directory of Open Access Journals (Sweden)

    Amita N Bhargava

    2014-01-01

    Full Text Available We describe a patient who presented with a history of lightning strike injury. Following the injury, he sustained acute right upper limb weakness with pain. Clinically, the lesion was located to the upper and middle trunk of the right brachial plexus, and the same confirmed with electrophysiological studies. Nerve damage due to lightning injuries is considered very rare, and a plexus damage has been described infrequently, if ever. Thus, the proposed hypothesis that lightning rarely causes neuropathy, as against high-voltage electric current, due to its shorter duration of exposure not causing severe burns which lead to nerve damage, needs to be reconsidered.

  9. Focused seismicity triggered by flank instability on Kīlauea's Southwest Rift Zone

    Science.gov (United States)

    Judson, Josiah; Thelen, Weston A.; Greenfield, Tim; White, Robert S.

    2018-03-01

    Swarms of earthquakes at the head of the Southwest Rift Zone on Kīlauea Volcano, Hawai´i, reveal an interaction of normal and strike-slip faulting associated with movement of Kīlauea's south flank. A relocated subset of earthquakes between January 2012 and August 2014 are highly focused in space and time at depths that are coincident with the south caldera magma reservoir beneath the southern margin of Kīlauea Caldera. Newly calculated focal mechanisms are dominantly dextral shear with a north-south preferred fault orientation. Two earthquakes within this focused area of seismicity have normal faulting mechanisms, indicating two mechanisms of failure in very close proximity (10's of meters to 100 m). We suggest a model where opening along the Southwest Rift Zone caused by seaward motion of the south flank permits injection of magma and subsequent freezing of a plug, which then fails in a right-lateral strike-slip sense, consistent with the direction of movement of the south flank. The seismicity is concentrated in an area where a constriction occurs between a normal fault and the deeper magma transport system into the Southwest Rift Zone. Although in many ways the Southwest Rift Zone appears analogous to the more active East Rift Zone, the localization of the largest seismicity (>M2.5) within the swarms to a small volume necessitates a different model than has been proposed to explain the lineament outlined by earthquakes along the East Rift Zone.

  10. Transpressional Structure in Chiayi Area, Taiwan: Insight from the 2017 ML5.1 Zhongpu Earthquake Sequence

    Science.gov (United States)

    Feng, K. F.; Huang, H. H.

    2017-12-01

    The Chiayi area is located at the deformation front of active fold-and-thrust belt of Taiwan, where the fault system is composed primarily of a series of north-south-trending east-dipping thrusts and also an east-west-trending strike-slip fault (Meishan Fault, MSF) with right-lateral faulting. On 24th May 2017, a ML 5.1 earthquake occurred at Zhongpu, Chiayi (namely Zhongpu earthquake), however, shows a left-lateral strike-slip faulting distinct from the known structure in the area. The distribution of the reported aftershocks is difficult to distinguish the actual fault plane. To determine the fault plane of this abnormal earthquake and investigate its structural relationships to the regional tectonics, we relocate the earthquake sequence and estimate the rupture directivity of the mainshock by using the 3-D double difference hypocenter relocation method (Lin, 2013) and the 3-D directivity moment tensor inversion method (DMT, Huang et al., 2017, submitted). The DMT results show that the rupture directivity of the Zhongpu earthquake is west- and down-ward along the east-west fault plane, which also agrees with east-west-distributed aftershocks after relocation. As a result, the Zhongpu earthquake reveals an undiscovered east-west-trending structure which is sub-parallel with the MSF but with opposite faulting direction, exhibiting a complex transpressional tectonic regime in the Chiayi area.

  11. ANALYSING POST-SEISMIC DEFORMATION OF IZMIT EARTHQUAKE WITH INSAR, GNSS AND COULOMB STRESS MODELLING

    Directory of Open Access Journals (Sweden)

    R. A. Barut

    2016-06-01

    Full Text Available On August 17th 1999, a Mw 7.4 earthquake struck the city of Izmit in the north-west of Turkey. This event was one of the most devastating earthquakes of the twentieth century. The epicentre of the Izmit earthquake was on the North Anatolian Fault (NAF which is one of the most active right-lateral strike-slip faults on earth. However, this earthquake offers an opportunity to study how strain is accommodated in an inter-segment region of a large strike slip fault. In order to determine the Izmit earthquake post-seismic effects, the authors modelled Coulomb stress changes of the aftershocks, as well as using the deformation measurement techniques of Interferometric Synthetic Aperture Radar (InSAR and Global Navigation Satellite System (GNSS. The authors have shown that InSAR and GNSS observations over a time period of three months after the earthquake combined with Coulomb Stress Change Modelling can explain the fault zone expansion, as well as the deformation of the northern region of the NAF. It was also found that there is a strong agreement between the InSAR and GNSS results for the post-seismic phases of investigation, with differences less than 2mm, and the standard deviation of the differences is less than 1mm.

  12. Analysis of Simulated Aircraft Lightning Strikes and Their Electromagnetic Effects

    National Research Council Canada - National Science Library

    Gruden, James

    2001-01-01

    To survive the intense electromagnetic fields associated with a lightning strike, proper design of aircraft electrical control systems requires knowledge of the transient current pulse associated with a lightning strike...

  13. Bird strike incidence at Addis Ababa Bole International Airport ...

    African Journals Online (AJOL)

    The time and rate of bird strike incidences, species composition and number of birds involved in strikes, and the behaviour of birds were recorded at Bole International Airport from December 1994 to December 1995. The gut contents of the birds struck by aircraft were analyzed. A total of 33 bird strikes were recorded during ...

  14. Evaluating the Effects of a Bird Strike Advisory System

    NARCIS (Netherlands)

    Metz, I.C.; Mühlhausen, T; Ellerbroek, J.; Hoekstra, J.M.

    2016-01-01

    Bird strikes have operational impacts and cause economic loss to the aviation industry. In the worst case, the damages resulting from bird strikes lead to crashes. The highest risk for bird strikes lies in the area below 3000 ft and thus mainly in airport environments. Despite intense efforts from

  15. effects of strike cost on economic development in nigeria

    African Journals Online (AJOL)

    USER

    productivity as in most cases strike cost (wages and salaries as well as other unavoidable payments) are paid during the .... Many times the Nigeria Labour Congress (NLC) and students have had to strike against ... the direct compensation package and other conditions of service. This is the most popular cause of strike in ...

  16. A Pyrenean Cretaceous extensional fault system in the Briançonnais Domain of the Alps: implications for the eastern termination of the segmented Bay of Biscay-Pyrenean rift system.

    Science.gov (United States)

    Tavani, Stefano; Bertok, Carlo; D'Atri, Anna; Piana, Fabrizio; Barale, Luca; Corradetti, Amerigo; Granado, Pablo; Martire, Luca; Vigna, Bartolomeo

    2017-04-01

    Recent studies in the foreland fold and thrust belt of the SW Alps reported that, in spite of the obliterating effect by the Alpine deformation, Mesozoic structures can still be recognised. These structures, occurring at the southern portion of the Western Alps arc, include a well-exposed crustal-scale Cretaceous extensional fault system. Field data (geological maps) and subsurface data (karst network) have been integrated to produce a detailed 3D reconstruction of this extensional fault system. Cretaceous faults affect the Paleozoic and Mesozoic successions and consist of a tens of km long E-W striking master fault, having in its northern block a set of E-dipping transverse extensional faults, having displacements in the order of hundreds of meters. The 3D reconstruction indicates that E-W extension, accommodated by transverse faults, is between 20% and 40%, and it reduces toward the E-W striking master fault. N-S extension is instead negligible and the E-W fault is interpreted as a Cretaceous right-lateral strike-slip fault. Removing the about 120° counter-clockwise vertical axis rotation, which is associated with the post-Cretaceous Alpine orogeny, the strike-slip fault becomes parallel to a suite of NNE-SSW to NE-SW striking faults occurring in the SW Alps foreland (present Provence region). We propose that, during the Cretaceous separation of Iberia from Eurasia, the NNE-SSW striking faults of Provence and Western Alps were delimiting to the east the Bay of Biscay - Pyrenean rift system. In detail, they formed a NNE-SSW striking transfer zone bounding to the east the Pyrenean arm of the rift, and likely ensured the connection of the Bay of Biscay - Pyrenean rift system with a further eastern, intra-plate, arm.

  17. Forward to the Past: Strikes and Striking as Dialogue by other ...

    African Journals Online (AJOL)

    In Nigeria, from the colonial period to the present, the employment of strikes and protests by nationalists, Nigerian workers and civil society groups has been established as one of the potent means of conveying viewpoints, positions as well as the demand for equality, fairness, social justice and reforms. It has been used as ...

  18. Coseismic displacement caused by the Mw 6.1 Mashhad earthquake in NE Iran from Sentinel-1A TOPS radar images

    Science.gov (United States)

    Su, Z.; Hu, J. C.; Talebian, M.

    2017-12-01

    Determining the relationship between crustal movement and associated slip partitioning is essential for understanding earthquake source and addressing the proposed models of a potential earthquake hazard. An Mw 6.1 earthquake struck the southeastern margin of the Mashhad valley in the northeast of Iran on 5 April 2017. In this study, we use both the ascending and descending mode of Sentinel-1A TOPS satellite data to characterize coseismic deformation pattern and to inverse the coseismic slip distribution on the fault patches. The best fitting model predicts that the coseismic rupture occurs along a fault plane with strike of 324.4º and dip of 28.1ºE. Our results show the fault tip does not propagate to the ground surface, and the predicted coseismic slip on the surface is about 0.11 m located on the hanging wall of the fault. Significant slip is concentrated on the fault patches at depth of 4-8 km and an along-strike distance of 10 km with varying slip magnitude from 0.1 m to 0.9 m. The fault slip is composed by thrusting with right-lateral strike slip, which is consistent with the focal mechanism solution. The over-thrusting was occurred from the depth of 14 km and terminated at the 4 km depth. While the right-lateral strike slip was only concentrated at a shallower depth of 4 to 8 km depth with the maximum slip of 0.9 m. The seismic moment release of our preferred fault model is 1.71×1018 Nm, equivalent to Mw 6.16 event. The Coulomb failure stress (CFS) calculated by the preferred fault model predicts significant positive CFS change on the three paralleled subsidiary faults of the southernmost Mashhad and Kashafrud fault, the Tus, Sorkhdeh and Natu faults. Consequently, these segments should be considered to have increasing of risk for future seismic hazard. Although most of the northward motion of the Lut and Central Iranian Blocks have been absorbed by the crustal shortening (e.g. thrusting and folding along the Binalud and Kopeh Dagh), simple strike-slip

  19. Comparison of air sac volume, lung volume, and lung densities determined by use of computed tomography in conscious and anesthetized Humboldt penguins (Spheniscus humboldti) positioned in ventral, dorsal, and right lateral recumbency.

    Science.gov (United States)

    Nevitt, Benjamin N; Langan, Jennifer N; Adkesson, Michael J; Mitchell, Mark A; Henzler, Margaret; Drees, Randi

    2014-08-01

    To determine the effects of recumbency on air sac volume, lung volume, and lung densities in CT images of healthy, conscious and anesthetized spontaneously breathing Humboldt penguins (Spheniscus humboldti). 25 adult (13 male and 12 female) Humboldt penguins. CT images of conscious penguins in ventral recumbency and anesthetized penguins in dorsal, ventral, and right lateral recumbency were obtained. Air sac volume, lung volume, and lung densities in CT images were calculated. A paired samples t test was used to determine whether right and left lung densities differed among recumbencies. Repeated-measures ANOVA (controlled for sex and order of recumbencies during CT) was used to determine whether air sac or lung volumes differed among recumbencies. Recumbency had a significant effect on air sac volume but not lung volume. Air sac volume was largest in conscious penguins in ventral recumbency (mean ± SD, 347.2 ± 103.1 cm(3)) and lowest in anesthetized penguins in dorsal recumbency (median, 202.0 cm(3); 10th to 90th percentile, 129.2 to 280.3 cm(3)). Lung densities were highest in anesthetized penguins in dorsal recumbency (right lung median, 0.522 g/cm(3); left lung median, 0.511 g/cm(3)) and lowest in anesthetized penguins in ventral recumbency (right lung median, 0.488 g/cm(3); left lung median, 0.482 g/cm(3)). Results indicated that anesthetized Humboldt penguins had the lowest air sac volume and highest lung densities in dorsal recumbency. Therefore, this recumbency may not be recommended. Minimal changes in lung volume were detected among recumbencies or between conscious and anesthetized penguins.

  20. Strike Point Control for the National Spherical Torus Experiment (NSTX)

    International Nuclear Information System (INIS)

    Kolemen, E.; Gates, D.A.; Rowley, C.W.; Kasdin, N.J.; Kallman, J.; Gerhardt, S.; Soukhanovskii, V.; Mueller, D.

    2010-01-01

    This paper presents the first control algorithm for the inner and outer strike point position for a Spherical Torus (ST) fusion experiment and the performance analysis of the controller. A liquid lithium divertor (LLD) will be installed on NSTX which is believed to provide better pumping than lithium coatings on carbon PFCs. The shape of the plasma dictates the pumping rate of the lithium by channeling the plasma to LLD, where strike point location is the most important shape parameter. Simulations show that the density reduction depends on the proximity of strike point to LLD. Experiments were performed to study the dynamics of the strike point, design a new controller to change the location of the strike point to desired location and stabilize it. The most effective PF coils in changing inner and outer strike points were identified using equilibrium code. The PF coil inputs were changed in a step fashion between various set points and the step response of the strike point position was obtained. From the analysis of the step responses, PID controllers for the strike points were obtained and the controller was tuned experimentally for better performance. The strike controller was extended to include the outer-strike point on the inner plate to accommodate the desired low outer-strike points for the experiment with the aim of achieving 'snowflake' divertor configuration in NSTX.

  1. Structural analysis of hanging wall and footwall blocks within the Río Guanajibo fold-and-thrust belt in Southwest Puerto Rico

    Science.gov (United States)

    Laó-Dávila, Daniel A.; Llerandi-Román, Pablo A.

    2017-01-01

    The Río Guanajibo fold-and-thrust belt (RGFT), composed of Cretaceous serpentinite and volcano-sedimentary rocks, represents the deformation front of a contractional event in SW Puerto Rico during the Paleogene. Previous studies inferred structural and stratigraphic relationships from poorly exposed outcrops. New road cuts exposed the Yauco (YF) and El Rayo Formations (ERF) providing insights on the deformation of the hanging wall and footwall. We described the nature and orientation of faults and folds and analyzed the kinematic indicators to characterize the deformation. The YF occurs in the hanging wall and shows a sequence of folded, medium-bedded mudstone and thinly bedded shale and sandstone. Major folds strike NW-SE and are gentle with steeply inclined axial planes and sub-horizontal fold axes. Minor folds are open with moderately inclined axial planes and gently to moderately inclined SE-plunging fold axes. NW-SE striking reverse and thrust faults cut layers and show movement to the SW. Steep left-lateral faults strike NW-SE and NE-SW, and smaller right-lateral strike-slip faults strike NNE-SSW. At the footwall, the ERF consists of bioclastic limestone and polymictic orthoconglomerates and paraconglomerates. Reverse and strike-slip faults cut along lithological contacts. Results suggest that the hanging wall and footwall accommodated strain along preexisting weaknesses, which are dependent on lithology and sedimentary structures. The kinematic analysis suggests that shortening in the NE-SW direction was partitioned between folding and interlayer shortening, accommodated by flexural slip, and reverse and left-lateral faults that resulted from contraction. The RGFT represents the Paleogene back arc deformation of a bivergent thrust system.

  2. Meso-Tethyan oceanic sutures and their deformation

    Science.gov (United States)

    Burtman, V. S.

    1994-07-01

    On the basis of comparative stratigraphie and paleontologic analysis, supported by some key paleomagnetic data and interpretations, it is shown that during the Mesozoic and the Cenozoic the Eurasian continent grew by accretion of microcontinents. These microcontinents separated basins with oceanic crust from the main ocean. During the Late Cretaceous and the early Cenozoic the collision of the microcontinents with Eurasia resulted in the closure of the basins, and Meso-Tethyan oceanic sutures originated. In the region under consideration, from the Carpathians to Tibet, there are two main Meso-Tethyan sutures: the Carpathian-Lesser Caucasus and the Afghan-Tibet suture. The above-mentioned main structures also had branches, which remained as sutures of small basins: the Kamennopotock, Interpontide, Nain-Baft basins and others. In the West Carpathians the Carpathian-Lesser Caucasus suture is overlain by a widespread Gemeric-Tatric allochton. From the West Carpathians the suture passes through the Pannonian basin into the Vardar ophiolite zone and farther to the ophiolites of the Izmir-Ankara zone. Being displaced along the North Anatolian right-lateral strike-slip fault, the main suture passes from the Eastern Pontides into the Lesser Caucasus, where it is marked by ophiolites of the Amasia area, the Shirak, Bozum and Zangezur ridges. Sunsequently, it can be observed through the Iranian Qara Dagh mountains to Lake Urumiyeh and the North Anatolian strike-slip fault. Being again shifted along the strike-slip fault, the Carpathian-Lesser Caucasus Meso-Tethyan suture ends in the Western Zagros near the Cenozoic Neo-Tethyan suture. The Afghan-Tibet Meso-Tethyan suture is situated in the Pamirs in the Rushan-Pshart zone. The east prolongation of the suture has been displaced along the Pamir-Karakorum right-lateral strike-slip fault in Tibet. West of the Pamirs this suture is also displaced along strike-slip faults and continues in the Farahrud zone in Afghanistan, and than

  3. Geological Effects on Lightning Strike Distributions

    KAUST Repository

    Berdahl, J. Scott

    2016-05-16

    Recent advances in lightning detection networks allow for detailed mapping of lightning flash locations. Longstanding rumors of geological influence on cloud-to-ground (CG) lightning distribution and recent commercial claims based on such influence can now be tested empirically. If present, such influence could represent a new, cheap and efficient geophysical tool with applications in mineral, hydrothermal and oil exploration, regional geological mapping, and infrastructure planning. This project applies statistical analysis to lightning data collected by the United States National Lightning Detection Network from 2006 through 2015 in order to assess whether the huge range in electrical conductivities of geological materials plays a role in the spatial distribution of CG lightning. CG flash densities are mapped for twelve areas in the contiguous United States and compared to elevation and geology, as well as to the locations of faults, railroads and tall towers including wind turbines. Overall spatial randomness is assessed, along with spatial correlation of attributes. Negative and positive polarity lightning are considered separately and together. Topography and tower locations show a strong influence on CG distribution patterns. Geology, faults and railroads do not. This suggests that ground conductivity is not an important factor in determining lightning strike location on scales larger than current flash location accuracies, which are generally several hundred meters. Once a lightning channel is established, however, ground properties at the contact point may play a role in determining properties of the subsequent stroke.

  4. Collective bargaining and strikes among physicians.

    Science.gov (United States)

    Keith, S N

    1984-11-01

    UNLIKE EMPLOYEES IN OTHER SECTORS OF THE ECONOMY, HEALTH CARE WORKERS ARE DIRECTED TOWARD ONE ULTIMATE GOAL: making people well and keeping them healthy. The development of collective bargaining and union activities during this century has had a great impact on all industries in the United States and the western world. However, only in recent years have workers in the health care sector been affected by the organized labor movement. The history of collective bargaining and strikes among physicians, the key decision-makers in the health care sector, is even more recent. Because of their central position, physicians' collective activity has had and will continue to have tremendous implications for the viability of the present health care system and the quality of patient care. Even though most physicians continue to function as individual, entrepreneurial service providers and "professionals," physicians as a group are more frequently being seen as members of a utility like industry. Their importance to individuals and society as a whole, it can be argued, is second to none; if physicians refuse to work there can be no worse set of outcomes. To estimate the potential future impact of growing collective action on the part of physicians, this article explores the general historical developments.

  5. Fracture structures of active Nojima fault, Japan, revealed by borehole televiewer imaging

    Science.gov (United States)

    Nishiwaki, T.; Lin, A.

    2017-12-01

    Most large intraplate earthquakes occur as slip on mature active faults, any investigation of the seismic faulting process and assessment of seismic hazards require an understanding of the nature of active fault damage zones as seismogenic source. In this study, we focus on the fracture structures of the Nojima Fault (NF) that triggered the 1995 Kobe Mw 7.2 earthquake using ultrasonic borehole televiewer (BHTV) images from a borehole wall. The borehole used in this study was drilled throughout the NF at 1000 m in depth by a science project of Drilling into Fault Damage Zone(DFDZ) in 2016 (Lin, 2016; Miyawaki et al., 2016). In the depth of consolidated sandstone and conglomerate of the Plio-Pleistocene Osaka-Group and mudstone and sandstone of the Miocene Kobe Group. The basement rock in the depth of >230 m consist of pre-Neogene granitic rock. Based on the observations of cores and analysis of the BHTV images, the main fault plane was identified at a depth of 529.3 m with a 15 cm thick fault gouge zone and a damage zone of 100 m wide developed in the both sides of the main fault plane. Analysis of the BHTV images shows that the fractures are concentrated in two groups: N45°E (Group-1), parallel to the general trend of the NF, and another strikes N70°E (Group-2), oblique to the fault with an angle of 20°. It is well known that Riedel shear structures are common within strike-slip fault zones. Previous studies show that the NF is a right-lateral strike-slip fault with a minor thrust component, and that the fault damage zone is characterized by Riedel shear structures dominated by Y shears (main faults), R shears and P foliations (Lin, 2001). We interpret that the fractures of Group (1) correspond to Y Riedel fault shears, and those of Group (2) are R shears. Such Riedel shear structures indicate that the NF is a right-lateral strike-slip fault which is activated under a regional stress field oriented to the direction close to east-west, coincident with that

  6. Children on hunger strike: child abuse or legitimate protest?

    Science.gov (United States)

    Mok, A.; Nelson, E. A.; Murphy, J.; Hampson, A.; Hendriks, J. H.

    1996-01-01

    The issue of children on hunger strike (voluntary total fasting) has not been reported before. The World Medical Association Declaration of Tokyo 1975 and the Declaration of Malta 1991 (revised 1992) provide clinicians with guidelines for the management of adult patients on hunger strike but do not mention children. We report the management of 14 Vietnamese children, aged 1 to 12 years, who took part in a hunger strike at a refugee detention centre in Hong Kong. PMID:8597690

  7. Children on hunger strike: child abuse or legitimate protest?

    OpenAIRE

    Mok, A.; Nelson, E. A.; Murphy, J.; Hampson, A.; Hendriks, J. H.

    1996-01-01

    The issue of children on hunger strike (voluntary total fasting) has not been reported before. The World Medical Association Declaration of Tokyo 1975 and the Declaration of Malta 1991 (revised 1992) provide clinicians with guidelines for the management of adult patients on hunger strike but do not mention children. We report the management of 14 Vietnamese children, aged 1 to 12 years, who took part in a hunger strike at a refugee detention centre in Hong Kong.

  8. The effect of hand dominance on martial arts strikes.

    Science.gov (United States)

    Neto, Osmar Pinto; Silva, Jansen Henrique; Marzullo, Ana Carolina de Miranda; Bolander, Richard P; Bir, Cynthia A

    2012-08-01

    The main goal of this study was to compare dominant and non-dominant martial arts palm strikes under different circumstances that usually happen during martial arts and combative sports applications. Seven highly experienced (10±5 years) right hand dominant Kung Fu practitioners performed strikes with both hands, stances with left or right lead legs, and with the possibility or not of stepping towards the target (moving stance). Peak force was greater for the dominant hand strikes (1593.76±703.45 N vs. 1042.28±374.16 N; p<.001), whereas no difference was found in accuracy between the hands (p=.141). Additionally, peak force was greater for the strikes with moving stance (1448.75±686.01 N vs. 1201.80±547.98 N; p=.002) and left lead leg stance (1378.06±705.48 N vs. 1269.96±547.08 N). Furthermore, the difference in peak force between strikes with moving and stationary stances was statistically significant only for the strikes performed with a left lead leg stance (p=.007). Hand speed was higher for the dominant hand strikes (5.82±1.08 m/s vs. 5.24±0.78 m/s; p=.001) and for the strikes with moving stance (5.79±1.01 m/s vs. 5.29±0.90 m/s; p<.001). The difference in hand speed between right and left hand strikes was only significant for strikes with moving stance. In summary, our results suggest that the stronger palm strike for a right-handed practitioner is a right hand strike on a left lead leg stance moving towards the target. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. The 2015, Mw 6.5, Leucas (Ionian Sea, Greece) earthquake: Seismological and Geodetic Modelling

    Science.gov (United States)

    Saltogianni, Vasso; Taymaz, Tuncay; Yolsal-Çevikbilen, Seda; Eken, Tuna; Moschas, Fanis; Stiros, Stathis

    2016-04-01

    A cluster of earthquakes (6Lefkada) earthquake. The modelling of these earthquakes, some of which are double events (2003 Leucas; 2014 Cephalonia) is a challenge for two main reasons. First, the geography of the area limits the distribution of the available seismological and GNSS stations and the correlations of INSAR data. Second, the structural pattern of the area indicates distributed thrusting but recent earthquakes are confined to the west margin of the Aegean Arc, usually assigned to the Cephalonia Transform Fault (CTF), and are dominated by strike slip faulting. In order to contribute to the understanding active tectonics along this critical region, our study was based on the independent analysis of the seismological and geodetic signature of the 2015 earthquake and the on the joint evaluation of the inferred models on the basis of the fault pattern of the area and of previous earthquakes. First, based on teleseismic long-period P- and SH- and broad-band P-waveforms a point-source solution at the SW part of Leucas yielded dominantly right-lateral strike-slip faulting mechanisms (strike: 23o, dip: 68o, rake: -170o) with a shallow focal depth (h: 9 km) and with seismic moment of Mo: 10.4x1018 Nm. Furthermore, the rupture history of the earthquake was obtained by applying a new back-projection method that uses teleseismic P-waveforms to integrate the direct P-phase with reflected phases from structural discontinuities near the source. In the slip inversion the faulting occurs on a single fault plane (strike and dip are obtained from the best fitting point-source solution) and slip (rake) angle varied during the whole rupture process. Second, co-seismic displacements were derived from eight permanent and one campaign GPS stations spread in the near and far field of the meizoseismal area. Significant horizontal slip was recognized, with a maximum dislocation of 36 cm in the SW part of Leucas island. Inversion of GPS-derived displacements using the new TOPological

  10. Debunking the viper's strike: harmless snakes kill a common assumption.

    Science.gov (United States)

    Penning, David A; Sawvel, Baxter; Moon, Brad R

    2016-03-01

    To survive, organisms must avoid predation and acquire nutrients and energy. Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes. However, strike performance has been measured in very few species, especially non-vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers, western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers. In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes. Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: the accelerations exceed values that can cause loss of consciousness in other animals, such as the accelerations experienced by jet pilots during extreme manoeuvres, and they make the strikes faster than the sensory and motor responses of mammalian prey and predators. Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move. © 2016 The Author(s).

  11. The characteristics of the western extension of the Karakax fault in NW Tibet and its tectonic implications

    Science.gov (United States)

    Ge, C.; Liu, D.; Li, H.; Zheng, Y.; Pan, J.

    2017-12-01

    The Karakax strike-slip fault, located in northwest Tibet, is a mature deformation belt with a long-time evolutionary history, which is also active at present and plays an important role in the tectonic deformation of the northwestern Tibetan Plateau. Nowadays, most geologists consider that the Karakax fault is generally east-west striking along the Karakax river valley, and northwest striking until to the Tashkorgan in the Mazar area. However, an ENE-WSW fault was identified at the Mazar area, which sited at the bend of the Karakax fault, we named this fault as the Matar fault. Via the detailed geological survey, the similar geometry and kinematic characteristics were identified between the Karakax and Matar faults: (1) The similar fault zone scale(Karakax:90 300m; Matar:100 220m); (2) The similar preferred orientation (nearly EW) of the stretching lineations and foliations; (3) All the fault planes of the both faults have a high dip angle and is nearly EW striking; (4) Lots of ductile deformations, such as σ-type quartz rotational mortar, S-C fabric, symmetric drag fold and so on, indicated that the Matar fault is a right-lateral strike-slip and thrust fault during the early ductile deformation stage; (5) the deluvium, sheared by Matar fault, indicated that the Matar fault has already transformed into a left-lateral strike-slip fault during the later brittle deformation stage. All the above showed that the Matar fault has a similar geometry and kinematic characteristics with the Karakax fault, and the former is the probable the western extension of the latter. Moreover, the form of the Karakax-Matar fault may had an impact to the geomorphology of the west Kunlun-Pamir area, such as the strike of the moutains and faults. considering the age of west Kunlun mountains uplifting and Karakax fault activating, we regard that the Matar fault (the westward extension of Karakax fault) may contributes much in forming the modern geomorphology features of the west Kunlun

  12. Strong Algerian Earthquake Strikes Near Capital City

    Science.gov (United States)

    Ayadi, A.; Maouche, S.; Harbi, A.; Meghraoui, M.; Beldjoudi, H.; Oussadou, F.; Mahsas, A.; Benouar, D.; Heddar, A.; Rouchiche, Y.; Kherroubi, A.; Frogneux, M.; Lammali, K.; Benhamouda, F.; Sebaï, A.; Bourouis, S.; Alasset, P. J.; Aoudia, A.; Cakir, Z.; Merahi, M.; Nouar, O.; Yelles, A.; Bellik, A.; Briole, P.; Charade, O.; Thouvenot, F.; Semane, F.; Ferkoul, A.; Deramchi, A.; Haned, S. A.

    On 21 May 2003, a damaging earthquake of Mw 6.8 struck the region of Boumerdes 40 km east of Algiers in northern Algeria (Figure 1). The mainshock, which lasted ~ 36-40 s, had devastating effects and claimed about 2300 victims, caused more than 11,450 injuries, and left about 200,000 people homeless. It destroyed and seriously damaged around 180,000 housing units and 6000 public buildings with losses estimated at $5 billion. The mainshock was widely felt within a radius of ~ 400 km in Algeria. To the north, the earthquake was felt in southeastern Spain, including the Balearic Islands, and also in Sardinia and in southern France. The mainshock location, which was calculated at 36.91°N, 3.58°E (15 km offshore of Zemmouri; Figure 1), and the local magnitude (Md 6.4) are from seismic records of local stations. International seismological centers obtained Mw 6.8 (NEIC) with a thrust focal mechanism solution and 1.83 × 1026 dyne.cm for the seismic moment. A sequence of aftershocks affected the epicentral area with two strong shocks reaching Mw 5.8 on 27 and 29 May 2003. Field investigations allowed us to assign a maximum intensity X (European Macroseismic Scale 98) and to report rockfalls, minor surface cracks, and liquefaction phenomena. The mainshock was not associated with inland surface faulting, but one of the most striking coseismic effects is the coastal uplift and the backwash along the littoral of the Mitidja basin.

  13. A decade of U.S. Air Force bat strikes

    Science.gov (United States)

    Peurach, Suzanne C.; Dove, Carla J.; Stepko, Laura

    2009-01-01

    From 1997 through 2007, 821 bat strikes were reported to the U.S. Air Force (USAF) Safety Center by aircraft personnel or ground crew and sent to the National Museum of Natural History, Smithsonian Institution, for identification. Many samples were identified by macroscopic and or microscopic comparisons with bat specimens housed in the museum and augmented during the last 2 years by DNA analysis. Bat remains from USAF strikes during this period were received at the museum from 40 states in the United States and from 20 countries. We confirmed that 46% of the strikes were caused by bats, but we did not identify them further; we identified 5% only to the family or genus level, and 49% to the species level. Fifty-five of the 101 bat-strike samples submitted for DNA analysis have been identified to the species level. Twenty-five bat species have been recorded striking USAF planes worldwide. The Brazilian free-tailed bat (Tadarida brasiliensis; n = 173) is the species most commonly identified in USAF strike impacts, followed by the red bat (Lasiurus borealis; n = 83). Bat strikes peak during the spring and fall, with >57% occurring from August through October; 82% of the reports that included time of strike were recorded between 2100 and 0900 hours. More than 12% of the bat strikes were reported at >300 m above ground level (AGL). Although $825,000 and >50% of this sum was attributable to 5 bat-strike incidents. Only 5 bats from the 10 most damaging bat strikes were identified to the species level, either because we did not receive remains with the reports or the sample was insufficient for identification.

  14. Structural development and stress evolution of an arcuate fold-and-thrust system, southwestern Greater Caucasus, Republic of Georgia

    Science.gov (United States)

    Tibaldi, A.; Bonali, F. L.; Russo, E.; Pasquarè Mariotto, F. A.

    2018-05-01

    The southern front of the Greater Caucasus is quite rectilinear in plan view, with the exception of part of the Rioni Basin, where marine and continental deposits of Cretaceous-Neogene age were locally folded and uplifted; this resulted in the formation of an arcuate fold-and-thrust system that extends 45 km into the foreland. Although previous studies suggested that this system has developed only since Miocene times, our new detailed and systematic field measurements of brittle and ductile structures show a very complex history, consisting in four main phases of brittle deformation and folding, dated from Eocene to Quaternary times. We collected microtectonic data at 248 faults, and calculated the related paleostress tensors. The first two phases which we document here, predated folding and were characterised by dominant transcurrent faulting and subordinate reverse motions; the greatest principal stress σ1 was perpendicular and later parallel to the mountain belt. Afterwards, NW-SE, E-W and NE-SW trending, south-vergent asymmetrical folds started to form. In the western sector of the study area, folds are sinuous in plan view, whereas to the east they show a left-stepping, en-échelon geometry. Another two, brittle deformation phases took place after the folding, due to the activity of a set of right-lateral, strike-slip faults that strike NW-SE and NE-SW, respectively, as well as by left-lateral strike-slip faults, mostly striking NW-SE, NE-SW and NNE-SSW. These two additional phases were produced by a NE-SW to N-S trending σ1. The arcuate belt is marked by along-strike variations in the tectonic regime and deformation geometry, plus belt-parallel stretching. Based on our field data, integrated with published analogue models, we suggest a possible explanation for the Rioni structure, in terms of the oblique, asymmetric indentation of an upper crustal blocks moving to the SSW.

  15. Simulation of co-seismic gravity change and deformation of Wenchuan Ms8. 0 earthquake

    Directory of Open Access Journals (Sweden)

    Chongyang Shen

    2010-01-01

    Full Text Available Surface co-seismic gravity changes and displacements caused by the Wenchuan Ms8. 0 earthquake are calculated on the basis of the half-space dislocation theory and two fault models inversed, respectively, by Institute of Geophysics, CEA and USGS. The results show that 1 the dislocation consists of dip slip and right-lateral strike slip; 2 the co-seismic gravity change shows a four-quadrant pattern, which is greatly controlled by the distribution of the vertical displacements, especially in the near-filed; 3 the gravity change is generally less than 10 × 10−8 ms−2 in the far-field, but as high as several 100 × 10−8 ms−2in the near-filed. These results basically agree with observational results.

  16. Rupture Along 400 km of the Bering Fracture Zone in the Komandorsky Islands Earthquake (MW 7.8) of 17 July 2017

    Science.gov (United States)

    Lay, Thorne; Ye, Lingling; Bai, Yefei; Cheung, Kwok Fai; Kanamori, Hiroo; Freymueller, Jeffrey; Steblov, Grigory M.; Kogan, Mikhail G.

    2017-12-01

    The 17 July 2017 Komandorsky Islands MW 7.8 earthquake involved arc-parallel right-lateral patchy strike-slip faulting along 400 km of the Bering Fracture Zone (BFZ) in the westernmost Aleutian Islands back arc. The large size of the earthquake indicates that the BFZ serves regionally as the primary plate boundary extending from the Near Islands to Kamchatka, with the fore-arc Komandorsky Sliver translating rapidly parallel to the Aleutian Trench. The slip distribution is determined by analysis of seismic, tsunami, and geodetic observations. Fault displacements of 4 to 8.5 m, mostly in the upper 15 km, but with localized extension to 20 to 30 km depth along a 100 km long segment of the BFZ, are comparable to the possible slip deficit since the last major earthquakes in this region in 1849 and 1858, given an estimated 5.1 cm/yr rate between the Komandorsky Sliver and the Bering Plate.

  17. Recent crustal movement and great earthquakes in Qinghai-Tibet sub-plate

    Directory of Open Access Journals (Sweden)

    Guo Liangqian

    2011-08-01

    Full Text Available Crustal movement and incremental-movement data observed repeatedly at GPS stations during 1999–2009 were analyzed to study the effect of two earthquakes of Ms8.1 and Ms8.0 that occurred in 2001 and 2008, respectively, in Qinghai-Tibet sub-plate and its eastern margin. The result revealed certain anomalous pre-earthquake deformation and some large co-seismic changes. Prior to the 2008 Wenchuan Ms8.0 earthquake, the seismogenic Kunlunshan fault zone became a geographic boundary between different regional movements. At the time of the earthquake, there was an average cross-fault crustal shortening of −1.04 m and an average right-lateral strike slip of 0.76 m along the ruptured segment, as well as a strain-energy release of −62. 66 × 10.7.

  18. Reporting the Great Railroad Strike: How Ideology Shaped the News.

    Science.gov (United States)

    Coward, John

    The Great Railroad Strike of 1877, a national catastrophe and the major news story of the year, was the first national labor strike in U.S. history. Because of the ideological bias of the press, specifically its implicit commitment to capitalism and to objectivity (itself a "myth" of social order), newspapers of the period could be…

  19. The public's attitude towards strike action by healthcare workers and ...

    African Journals Online (AJOL)

    The strength of the associations was determined by Cramer's V. Results. Results revealed strong opinions among the population regarding strikes, numerous misapprehensions when it comes to striking and rights, a poor awareness of other healthcare-related rights and the perception of poor treatment at public hospitals.

  20. Teaching Striking Skills in Elementary Physical Education Using Woodball

    Science.gov (United States)

    Chang, Seung Ho; Lee, Jihyun

    2017-01-01

    Object control (OC) skills are a part of fundamental motor skills and basic functional skills, which work as a prerequisite to becoming a skilled performer in many sports. Of various OC skills, striking is one of the most difficult to master due to a variety of interrelated movement components. A form of vertical or underarm striking is a more…

  1. LAW AND ETHICS OF STRIKES IN THE NIGERIAN HEALTH SYSTEM

    African Journals Online (AJOL)

    2014-10-06

    Oct 6, 2014 ... employment. Kidnapping has been affecting virtually every sector of the Nigerian economy. Thus it is not the right of any health worker to embark on strike. Rather the right to strike can be derived from the principle of collective bargaining, which according to Ahmed (2014) is an essential principle. Workers ...

  2. Ban on right to strike by police challenged

    NARCIS (Netherlands)

    Grünell, M.

    2008-01-01

    After months of negotiation between the police force and the minister of the interior on the renewal of the collective agreement, the police trade unions began threatening industrial action and strikes in December 2007. The courts were divided on the issue, with some ruling out strikes as a means of

  3. Martial arts striking hand peak acceleration, accuracy and consistency.

    Science.gov (United States)

    Neto, Osmar Pinto; Marzullo, Ana Carolina De Miranda; Bolander, Richard P; Bir, Cynthia A

    2013-01-01

    The goal of this paper was to investigate the possible trade-off between peak hand acceleration and accuracy and consistency of hand strikes performed by martial artists of different training experiences. Ten male martial artists with training experience ranging from one to nine years volunteered to participate in the experiment. Each participant performed 12 maximum effort goal-directed strikes. Hand acceleration during the strikes was obtained using a tri-axial accelerometer block. A pressure sensor matrix was used to determine the accuracy and consistency of the strikes. Accuracy was estimated by the radial distance between the centroid of each subject's 12 strikes and the target, whereas consistency was estimated by the square root of the 12 strikes mean squared distance from their centroid. We found that training experience was significantly correlated to hand peak acceleration prior to impact (r(2)=0.456, p =0.032) and accuracy (r(2)=0. 621, p=0.012). These correlations suggest that more experienced participants exhibited higher hand peak accelerations and at the same time were more accurate. Training experience, however, was not correlated to consistency (r(2)=0.085, p=0.413). Overall, our results suggest that martial arts training may lead practitioners to achieve higher striking hand accelerations with better accuracy and no change in striking consistency.

  4. Risk Considerations of Bird Strikes to Space Launch Vehicles

    Science.gov (United States)

    Hales, Christy; Ring, Robert

    2016-01-01

    Within seconds after liftoff of the Space Shuttle during mission STS-114, a turkey vulture impacted the vehicle's external tank. The contact caused no apparent damage to the Shuttle, but the incident led NASA to consider the potential consequences of bird strikes during a Shuttle launch. The environment at Kennedy Space Center provides unique bird strike challenges due to the Merritt Island National Wildlife Refuge and the Atlantic Flyway bird migration routes. NASA is currently refining risk assessment estimates for the probability of bird strike to space launch vehicles. This paper presents an approach for analyzing the risks of bird strikes to space launch vehicles and presents an example. The migration routes, types of birds present, altitudes of those birds, exposed area of the launch vehicle, and its capability to withstand impacts affect the risk due to bird strike. A summary of significant risk contributors is discussed.

  5. Power electromagnetic strike machine for engineering-geological surveys

    Science.gov (United States)

    Usanov, K. M.; Volgin, A. V.; Chetverikov, E. A.; Kargin, V. A.; Moiseev, A. P.; Ivanova, Z. I.

    2017-10-01

    When implementing the processes of dynamic sensing of soils and pulsed nonexplosive seismic exploration, the most common and effective method is the strike one, which is provided by a variety of structure and parameters of pneumatic, hydraulic, electrical machines of strike action. The creation of compact portable strike machines which do not require transportation and use of mechanized means is important. A promising direction in the development of strike machines is the use of pulsed electromagnetic actuator characterized by relatively low energy consumption, relatively high specific performance and efficiency, and providing direct conversion of electrical energy into mechanical work of strike mass with linear movement trajectory. The results of these studies allowed establishing on the basis of linear electromagnetic motors the electromagnetic pulse machines with portable performance for dynamic sensing of soils and land seismic pulse of small depths.

  6. Geodynamics of Modern Structures and Seismotectonics of the Russian Northeast

    Science.gov (United States)

    Mackey, K. G.; Imaeva, L.; Gusev, G. S.; Imaev, V.; Fujita, K.; Vel'nikova, V. I.; Ashurkov, S. V.; Seredkina, A. I.

    2017-12-01

    We conducted an interdisciplinary study of the Arctic, Chersky, and Okhotsk-Chukotka seismic belts, which bound the Kolyma-Chukotka block of the North American plate in Northeast Russia, to determine the stress-strain state of the crust and the types of seismic deformation therein. The rank and class of neotectonic structures was based on their degrees of geodynamic activity, structural position, deep structure, and their active fault systems. The tectonic stress field was determined from Late Cenozoic faults and folds and average seismic moment tensors from earthquake focal mechanisms. Using geological, structural, geophysical and GPS data and average strain tensors, we determined the directions of the principal stress axes and the variation of tectonic settings in the Russian Northeast. Within the boundary zones between the Kolyma-Chukotka block and the Eurasian, Bering Sea and Pacific plates, the geodynamic settings change from one segment to another as follows: the crust is under extension in the Gakkel Ridge segment (Arctic belt) as the lithospheric plates diverge; the Laptev Sea shelf and Kharaulakh segments comprise a transitional zone with mixed stresses; in the Chersky seismic belt, left-lateral strike-slip faulting occurs from northeast compression due to the oblique convergence of the North American and Eurasian plates; in the Commander and Aleutian Islands segment, right-lateral strike-slip faulting is caused by the northwestward convergence and higher relative velocity of the Pacific plate; the crust is under compression due to convergence with the Bering Sea plate in the Koryak segment (Okhotsk-Chukotka seismic belt), resulting in systems of reverse, thrust and right-lateral strike-slip faults. To the northeast, this transitions into the extension of the Bering Sea rift. The seismotectonic data from the active boundaries of the Kolyma-Chukotka block are consistent with the distribution and types of observed structural features in each belt and segment

  7. Wavelet transform analysis of electromyography kung fu strikes data.

    Science.gov (United States)

    Neto, Osmar Pinto; Marzullo, Ana Carolina de Miranda

    2009-11-01

    In martial arts and contact sports strikes are performed at near maximum speeds. For that reason, electromyography (EMG) analysis of such movements is non-trivial. This paper has three main goals: firstly, to investigate the differences in the EMG activity of muscles during strikes performed with and without impacts; secondly, to assess the advantages of using Sum of Significant Power (SSP) values instead of root mean square (rms) values when analyzing EMG data; and lastly to introduce a new method of calculating median frequency values using wavelet transforms (WMDF). EMG data of the deltoid anterior (DA), triceps brachii (TB) and brachioradialis (BR) muscles were collected from eight Kung Fu practitioners during strikes performed with and without impacts. SSP results indicated significant higher muscle activity (p = 0.023) for the strikes with impact. WMDF results, on the other hand, indicated significant lower values (p = 0. 007) for the strikes with impact. SSP results presented higher sensitivity than rms to quantify important signal differences and, at the same time, presented lower inter-subject coefficient of variations. The result of increase in SSP values and decrease in WMDF may suggest better synchronization of motor units for the strikes with impact performed by the experienced Kung Fu practitioners. Key PointsThe results show higher muscle activity and lower electromyography median frequencies for strikes with impact compared to strikes without.SSP results presented higher sensitivity and lower inter-subject coefficient of variations than rms results.Kung Fu palm strikes with impact may present better motor units' synchronization than strikes without.

  8. Differential Energy Radiation from Two Earthquakes in Japan with Identical MW

    Science.gov (United States)

    Choy, G. L.; Boatwright, J.

    2007-12-01

    Teleseismic studies have found that in general the radiated energy ES of intraplate strike-slip earthquakes is elevated significantly for a given rupture size (as measured by moment) relative to the energies radiated by thrust earthquakes at subduction zones. We verify that this phenomenon can be observed for regional (217 K-net stations with a resulting ES of 1.3e15 J. The attenuation functions derived for these earthquakes are comparable to those derived from other studies of earthquakes in Japan as well as central California for f > 1.0 Hz. The ES of the strike-slip earthquake is more than three times larger than that of the thrust earthquake. Commensurate with the difference in energies, the macroseismic effects as reported for the strike-slip earthquake were more severe and widespread than effects reported for the thrust earthquake. However, from teleseismic data the energy of the strike-slip earthquake is a factor of 10 larger than that of the thrust earthquake. For the strike-slip earthquake, the acceleration spectra of teleseismic and regional analyses overlap smoothly. Good regional-teleseismic overlap has been seen in analyses of other strike-slip earthquakes such as the Hector Mines event. In contrast, for the Kyushu earthquake, the teleseismic analysis appeared to underestimate energy at a band of frequencies about 1.0 Hz relative to the regional data. A similar difference between regional and teleseismic spectra has been observed for the North Ridge and San Simeon, California thrust events.

  9. Bayesian inference and interpretation of centroid moment tensors of the 2016 Kumamoto earthquake sequence, Kyushu, Japan

    Science.gov (United States)

    Hallo, Miroslav; Asano, Kimiyuki; Gallovič, František

    2017-09-01

    On April 16, 2016, Kumamoto prefecture in Kyushu region, Japan, was devastated by a shallow M JMA7.3 earthquake. The series of foreshocks started by M JMA6.5 foreshock 28 h before the mainshock. They have originated in Hinagu fault zone intersecting the mainshock Futagawa fault zone; hence, the tectonic background for this earthquake sequence is rather complex. Here we infer centroid moment tensors (CMTs) for 11 events with M JMA between 4.8 and 6.5, using strong motion records of the K-NET, KiK-net and F-net networks. We use upgraded Bayesian full-waveform inversion code ISOLA-ObsPy, which takes into account uncertainty of the velocity model. Such an approach allows us to reliably assess uncertainty of the CMT parameters including the centroid position. The solutions show significant systematic spatial and temporal variations throughout the sequence. Foreshocks are right-lateral steeply dipping strike-slip events connected to the NE-SW shear zone. Those located close to the intersection of the Hinagu and Futagawa fault zones are dipping slightly to ESE, while those in the southern area are dipping to WNW. Contrarily, aftershocks are mostly normal dip-slip events, being related to the N-S extensional tectonic regime. Most of the deviatoric moment tensors contain only minor CLVD component, which can be attributed to the velocity model uncertainty. Nevertheless, two of the CMTs involve a significant CLVD component, which may reflect complex rupture process. Decomposition of those moment tensors into two pure shear moment tensors suggests combined right-lateral strike-slip and normal dip-slip mechanisms, consistent with the tectonic settings of the intersection of the Hinagu and Futagawa fault zones.[Figure not available: see fulltext.

  10. Strikes by physicians: a historical perspective toward an ethical evaluation.

    Science.gov (United States)

    Thompson, Stephen L; Salmon, J Warren

    2006-01-01

    Current conditions surrounding the house of medicine-including corporate and government cost-containment strategies, increasing market-penetration schemes in health care, along with clinical scrutiny and the administrative control imposed under privatization by managed care firms, insurance companies, and governments-have spurred an upsurge in physician unionization, which requires a revisiting of the issue of physician strikes. Strikes by physicians have been relatively rare events in medical history. When they have occurred, they have aroused intense debate over their ethical justification among professionals and the public alike, notwithstanding what caused the strikes. As physicians and other health care providers increasingly find employment within organizations as wage-contract employees and their work becomes more highly rationalized, more physicians will join labor organizations to protect both their economic and their professional interests. As a result, these physicians will have to come to terms with the use of the strike weapon. On the surface, many health care strikes may not ever seem justifiable, but in certain defined situations a strike would be not only permissible but an ethical imperative. With an exacerbation of labor strife in the health sector in many nations, it is crucial to explore the question of what constitutes an ethical physician strike.

  11. Determine the Foot Strike Pattern Using Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Tzyy-Yuang Shiang

    2016-01-01

    Full Text Available From biomechanical point of view, strike pattern plays an important role in preventing potential injury risk in running. Traditionally, strike pattern determination was conducted by using 3D motion analysis system with cameras. However, the procedure is costly and not convenient. With the rapid development of technology, sensors have been applied in sport science field lately. Therefore, this study was designed to determine the algorithm that can identify landing strategies with a wearable sensor. Six healthy male participants were recruited to perform heel and forefoot strike strategies at 7, 10, and 13 km/h speeds. The kinematic data were collected by Vicon 3D motion analysis system and 2 inertial measurement units (IMU attached on the dorsal side of both shoes. The data of each foot strike were gathered for pitch angle and strike index analysis. Comparing the strike index from IMU with the pitch angle from Vicon system, our results showed that both signals exhibited highly correlated changes between different strike patterns in the sagittal plane (r=0.98. Based on the findings, the IMU sensors showed potential capabilities and could be extended beyond the context of sport science to other fields, including clinical applications.

  12. Strike action by nurses in South Africa: A value clarification

    Directory of Open Access Journals (Sweden)

    Marie Muller

    2001-09-01

    Full Text Available The Labour Relations Act (South Africa, 1991 made provision for protected strike action by employees, subject to certain conditions, procedures and negotiated agreements. This led to the removal of the strike clause in the Nursing Act (South Africa, 1992. The labour rights of all citizens are entrenched in the Constitution of the country (South Africa, 1996. Participation in strike action by the nurse/ midwife, regardless of the legal requirements and specifications, does, however, pose an ethical question. It is therefore necessary to conduct a value clarification on strike action by nurses in South Africa. The purpose of this research is to explore and describe the perceived values of participants from an accessible population on this phenomenon. A qualitative, exploratory and descriptive research design was deployed. The perceived values of nurses on strike action were collected by means of an openended questionnaire/sketch. Over a period of three years a purposive and convenient sampling method was used, involving all the enrolled post basic nursing/midwifery students/ learners at a particular Nursing Education Institution. The justification of the sample was further enhanced by also collecting data on the participants’ age and provincial distribution location. Although a 63% sample realisation (of the accessible population was achieved, this represents only 1,5% of the registered nursing/midwifery population in the country. A descriptive analysis of the participants’ age and provincial distribution was undertaken, as well as a content analysis of their perceived values on strike action. The mean age of the participants was 48 years, which could be attributed to the fact that most of them were enrolled for a post-basic Diploma in Community Nursing Science. Most of the responses (52,7% were against strike action and 32,5% supported strike action by nurses as a constitutional and legal right. A fairly substantial number of participants (14

  13. "Thunderstruck": penetrating thoracic injury from lightning strike.

    Science.gov (United States)

    van Waes, Oscar J F; van de Woestijne, Pieter C; Halm, Jens A

    2014-04-01

    Lightning strike victims are rarely presented at an emergency department. Burns are often the primary focus. This case report describes the improvised explosive device like-injury to the thorax due to lightning strike and its treatment, which has not been described prior in (kerauno)medicine. Penetrating injury due to blast from lightning strike is extremely rare. These "shrapnel" injuries should however be ruled out in all patients struck by lightning. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

  14. Causative Fault of 2016 ML 5.8 Gyeongju Earthquake (SE Korea): Structural and Seismic characteristics

    Science.gov (United States)

    Ha, S.; Cheon, Y.; Lee, Y.; Kim, J.; Kim, K. H.; Son, M.

    2017-12-01

    A ML 5.8 earthquake, the largest instrumental earthquake in the Korean peninsula, occurred on 12 September 2016 in the Gyeongju-city, SE Korea, where is regarded as a stable intraplate region. The earthquake was widely felt in the southern peninsula and had a maximum MMI VIII in the epicentral region. Most of the intraplate earthquakes occur along preexisting weaknesses, but the potentially seismogenic structures are mostly not exposed at the surface. This study focuses on (1) the structural features in the neighboring area of the epicenter, (2) the distribution of earthquake hypocenter locations during the first 10 days of the aftershock sequence of the Gyeongju earthquake, and (3) the focal mechanism solution of select events to reveal the geometry and kinematics of its causative fault. The earthquake hypocenters in plan view clearly show a linear distribution of N 28°E, which extends about 7 km southwestward from the Yangsan Fault to the Deokcheon Fault. In cross-sectional views along N28°E and perpendicularly, the hypocenters at depths between 11 and 16 km clearly delineate a subsurface fault which has a rupturing size of about 3 ´ 3 km2 and a dip of 78°SE. Based on focal mechanism solutions, the fault acted as dextral strike-slip fault under ENE-WSW compressional stress that has been widely known as the major component of current stress field in and around Korean peninsula. The general trend, N 28°E, of the seismogenic fault slightly differs from the strike of the adjacent NNE-striking Yangsan Fault with an angular difference of 15°. The Yangsan fault is the most prominent dextral strike-slip fault in SE Korea, which can be traced for 170 km with a right-lateral offset of 30 km. The strike-slip movement is well-reported to have occurred during the Paleogene. At that time, probably numerous subsidiary fractures, such as Y-, R-, R'-, and T fractures, in various directions were produced along the Yangsan master fault. It is thus interpreted that a large R

  15. Geodynamics and Stress State of the Earth's Crust in the Greater and Lesser Caucasus (Azerbaijan) collision region

    Science.gov (United States)

    Babayev, Gulam; Akhmedova, Elnare; Babayev, Elvin

    2017-04-01

    The current study researches the present-day stress state of the Earth's crust within the territory of Azerbaijan by using the database of the international research project "World Stress Map" (WSM). The present stress state was also assessed by exploring the effects of the contemporary topographic properties of Caucasus in three-dimensional frame. Aiming to explore the relative roles of regional tectonic conditions in the definition of stress state of Greater and Lesser Caucasus, stress distribution model was developed by the earthquake data (1998-2016) and by the standard techniques of stress field calculation. The results show that the stress orientations are influenced also by the combination of topography and crust thickness distribution even at very large depth. Stress data and earthquake focal mechanisms indicate that the stress state of the Earth's crust of the Greater and Lesser Caucasus is characterized by the compression predominantly oriented across the regional strike. The model results suggest that the Lesser Caucasus and Kur depression are rotating coherently, with little or no internal deformation in a counter-clockwise rotation located near the north-eastern corner of the Black Sea. Orientation of stress axes well consistent with earthquake focal mechanisms revealed that within Upper and Lower Crusts, earthquakes are predominantly thrust-faulting with a number of normal-faulting and some strike-slip faulting. The map of the focal mechanisms and stress distribution suggests that the research area is characterized by the thrust of horizontal compression trending north-north-east in the western part of the southern Caucasus. In the western part of Azerbaijan, the compression takes place between the Main Caucasus Fault and the Kur depression, which strikes south along the northern margin of the mountain range. In addition, a clear transition from the left-lateral strike slip to the predominantly right-lateral strike slip is observed in the southern of

  16. Seismic Evidence for Conjugate Slip and Block Rotation Within the San Andreas Fault System, Southern California

    Science.gov (United States)

    Nicholson, Craig; Seeber, Leonardo; Williams, Patrick; Sykes, Lynn R.

    1986-08-01

    The pattern of seismicity in southern California indicates that much of the activity is presently occurring on secondary structures, several of which are oriented nearly orthogonal to the strikes of the major through-going faults. Slip along these secondary transverse features is predominantly left-lateral and is consistent with the reactivation of conjugate faults by the current regional stress field. Near the intersection of the San Jacinto and San Andreas faults, however, these active left-lateral faults appear to define a set of small crustal blocks, which in conjunction with both normal and reverse faulting earthquakes, suggests contemporary clockwise rotation as a result of regional right-lateral shear. Other left-lateral faults representing additional rotating block systems are identified in adjacent areas from geologic and seismologic data. Many of these structures predate the modern San Andreas system and may control the pattern of strain accumulation in southern California. Geodetic and paleomagnetic evidence confirm that block rotation by strike-slip faulting is nearly ubiquitous, particularly in areas where shear is distributed, and that it accommodates both short-term elastic and long-term nonelastic strain. A rotating block model accounts for a number of structural styles characteristic of strike-slip deformation in California, including: variable slip rates and alternating transtensional and transpressional features observed along strike of major wrench faults; domains of evenly-spaced antithetic faults that terminate against major fault boundaries; continued development of bends in faults with large lateral displacements; anomalous focal mechanisms; and differential uplift in areas otherwise expected to experience extension and subsidence. Since block rotation requires a detachment surface at depth to permit rotational movement, low-angle structures like detachments, of either local or regional extent, may be involved in the contemporary strike-slip

  17. Continental United States Hurricane Strikes 1950-2012

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Continental U.S. Hurricane Strikes Poster is our most popular poster which is updated annually. The poster includes all hurricanes that affected the U.S. since...

  18. 2005 Significant U.S. Hurricane Strikes Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2005 Significant U.S. Hurricane Strikes poster is one of two special edition posters for the Atlantic Hurricanes. This beautiful poster contains two sets of...

  19. Ethical and legal consideration of prisoner's hunger strike in Serbia.

    Science.gov (United States)

    Alempijevic, Djordje; Pavlekic, Snezana; Jecmenica, Dragan; Nedeljkov, Aleksandra; Jankovic, Milos

    2011-03-01

    Hunger strike of prisoners and detainees remains a major human rights and ethical issue for medical professionals. We are reporting on a case of a 48-year-old male sentenced prisoner, intravenous heroin user, who went on a hunger strike and died 15 days later. Throughout the fasting period, the prisoner, who was capable of decision making, refused any medical examination. Autopsy findings were not supporting prolonged starvation, while toxicology revealed benzodiazepines and opiates in blood and urine. Cause of death was given as "heroin intoxication" in keeping with detection of 6-MAM. Legal and ethical issues pertinent to medical examination and treatment of prisoners on hunger strike are explored in accordance with legislation and professional ethical standards in Serbia. A recommendation for the best autopsy practice in deaths following hunger strike has been made. © 2011 American Academy of Forensic Sciences.

  20. Nuclear First Strike-Have the Rules Changed?

    National Research Council Canada - National Science Library

    Carter, Rosemary M

    2008-01-01

    .... Nuclear first strike is the policy that reserves the right to use nuclear weapons against an enemy before that enemy employs a like weapon without any constraints on the decision to employ the weapon...

  1. Joint Strike Fighter fit for duty in Europe?

    NARCIS (Netherlands)

    Heerkens, Johannes M.G.

    2000-01-01

    Focuses on the potential growth of the Joint Strike Fighter (JSF) market in Europe. Competition between Lockheed Martin and Boeing for the fighter's design contract; Disadvantages of the fighter plane; Stealth performance of JSF.

  2. Comparison of force, power, and striking efficiency for a Kung Fu strike performed by novice and experienced practitioners: preliminary analysis.

    Science.gov (United States)

    Neto, Osmar Pinto; Magini, Marcio; Saba, Marcelo M F; Pacheco, Marcos Tadeu Tavares

    2008-02-01

    This paper presents a comparison of force, power, and efficiency values calculated from Kung Fu Yau-Man palm strikes, when performed by 7 experienced and 6 novice men. They performed 5 palm strikes to a freestanding basketball, recorded by high-speed camera at 1000 Hz. Nonparametric comparisons and correlations showed experienced practitioners presented larger values of mean muscle force, mean impact force, mean muscle power, mean impact power, and mean striking efficiency, as is noted in evidence obtained for other martial arts. Also, an interesting result was that for experienced Kung Fu practitioners, muscle power was linearly correlated with impact power (p = .98) but not for the novice practitioners (p = .46).

  3. Local avian density influences risk of mortality from window strikes

    Science.gov (United States)

    Sabo, Ann M.; Hagemeyer, Natasha D.G.; Lahey, Ally S.

    2016-01-01

    Up to a billion birds die per year in North America as a result of striking windows. Both transparent and reflective glass panes are a cause for concern, misleading birds by either acting as invisible, impenetrable barriers to desired resources, or reflecting those resources over a large surface area. A high number of window strikes occur during migration, but little is known about the factors of susceptibility, or whether particular avian taxa are more vulnerable than others. We report on a study of window strikes and mist-netting data at the Virginia Zoological Park (Norfolk, Virginia, USA), conducted in the autumn of 2013 and 2014. We focused on three factors likely to contribute to an individual’s predisposition to collide with windows: (i) taxonomic classification, (ii) age, and (iii) migrant vs. resident status. Thrushes, dominated by the partial migrant American Robin (Turdus migratorius), were significantly less likely to strike glass than be sampled in mist nets (χ2 = 9.21, p = 0.002), while wood-warblers (Parulidae) were more likely to strike than expected (χ2 = 13.55, p windows (45.4%) was not significantly different (χ2 = 0.05, p = 0.827) than the population of juvenile birds naturally occurring at the zoo (48.8%). Migrants, however, were significantly more susceptible to window strikes than residents (χ2 = 6.35, p = 0.012). Our results suggest that resident birds are able to learn to avoid and thus reduce their likelihood of striking windows; this intrinsic risk factor may help explain the apparent susceptibility of certain taxa to window strikes. PMID:27366656

  4. NASA storm hazards research in lightning strikes to aircraft

    Science.gov (United States)

    Fisher, B. D.; Brown, P. W.; Plumer, J. A.

    1985-01-01

    The lightning strike condition data gathered in the 1980-1984 period are presented, together with the lightning attachment point analysis for the NASA F-106B research aircraft are presented. The analysis of the experienced 637 direct lightning strikes shows that the highest strike rates (2.1 strikes/min and 13 strikes/penetration) occurred at altitudes between 38,000 and 40,000 ft. The regions of highest risk for an aircraft to experience a direct lightning strike were the areas of thunderstorms where the ambient temperature was colder than -40 C and where the relative turbulence and precipitation intensities were characterized as negligible to light. The presence and location of lightning, therefore, did not necessarily indicate the presence and location of hazardous precipitation and turbulence. The total onboard data show that the lightning attachment patterns on this aircraft fall into four general categories, although the 1984 data suggest that the entire surface of the F-106B may be susceptible to lightning attachment.

  5. WAVELET TRANSFORM ANALYSIS OF ELECTROMYOGRAPHY KUNG FU STRIKES DATA

    Directory of Open Access Journals (Sweden)

    Ana Carolina de Miranda Marzullo

    2009-11-01

    Full Text Available In martial arts and contact sports strikes are performed at near maximum speeds. For that reason, electromyography (EMG analysis of such movements is non-trivial. This paper has three main goals: firstly, to investigate the differences in the EMG activity of muscles during strikes performed with and without impacts; secondly, to assess the advantages of using Sum of Significant Power (SSP values instead of root mean square (rms values when analyzing EMG data; and lastly to introduce a new method of calculating median frequency values using wavelet transforms (WMDF. EMG data of the deltoid anterior (DA, triceps brachii (TB and brachioradialis (BR muscles were collected from eight Kung Fu practitioners during strikes performed with and without impacts. SSP results indicated significant higher muscle activity (p = 0.023 for the strikes with impact. WMDF results, on the other hand, indicated significant lower values (p = 0. 007 for the strikes with impact. SSP results presented higher sensitivity than rms to quantify important signal differences and, at the same time, presented lower inter-subject coefficient of variations. The result of increase in SSP values and decrease in WMDF may suggest better synchronization of motor units for the strikes with impact performed by the experienced Kung Fu practitioners

  6. Seismotectonics of the Nicobar Swarm and the geodynamic implications for the 2004 Great Sumatran Earthquake

    Science.gov (United States)

    Lister, Gordon

    2017-04-01

    facilitated by hydrothermal activity related to a seamount, or by magma intrusion. However, the swarm is located where the transpressional regime of the Sumatran strike-slip fault system changes to that of the 'microplate-bounding' transtensional wrench involved in the Andaman Sea spreading centre. The swarm thus may be the result of the confluence of two tectonic modes of afterslip on the main rupture, with arc-normal compression to the south, and arc-normal extension to the north. The orientations of the controlling faults can be related to the right-lateral Sumatran strike-slip system, and to oceanic transforms in the spreading system. Faults parallel to the Andaman Sea spreading system axis reactivated as left-lateral strike-slip faults during the period of afterslip. Analysis of the orientation groups shows that the swarm involved synchronous but geometrically incompatible movements on opposing but conjugate fault plane sets with trends that are consistent with Mohr-Coulomb failure, even though the orientation groups delineated require slip in many different directions on these planes. The fault planes allow inference of regional deviatoric stress axes with the principal compressive stress parallel to the prior distortion inferred using satellite geodesy.

  7. Mesozoic to Cenozoic tectonic transition process in Zhanhua Sag, Bohai Bay Basin, East China

    Science.gov (United States)

    Cheng, Yanjun; Wu, Zhiping; Lu, Shunan; Li, Xu; Lin, Chengyan; Huang, Zheng; Su, Wen; Jiang, Chao; Wang, Shouye

    2018-04-01

    The Zhanhua sag is part of the Bohai Bay intracontinental basin system that has developed since the Mesozoic in East China. The timing of this basin system coincides with the final assembly of East Asia and the development of Western Pacific-type plate margin. Here we use 3-D seismic and core log data to investigate the evolution of this basin and discuss its broad tectonic settings. Our new structural study of Zhanhua sag suggests that there are four major tectonic transitions occurred in the Bohai Bay Basin during Mesozoic and Cenozoic: (1) The first tectonic transition was from stable Craton to thrusting during the Triassic, mainly caused by the South China Block's subduction northward beneath the North China Block, which induced the formation of the NW-striking thrust faults. (2) The second tectonic transition was mainly characterized by a change from compression to extension, which can be further divided into two-stages. At the first stage, two episodes of NW-SE shortening occurred in East Asia during Early-Middle Jurassic and Late Jurassic-earliest Cretaceous, respectively. At the second stage, the extension and left-lateral shearing took place during Early Cretaceous while compression occurred during Late Cretaceous. The NW-striking thrust faults changed to normal faults and the NNE-striking left-lateral strike-slip faults started to influence the eastern part of the basin. (3) The third transition occurred when the NW-SE extension and NNE-striking right-lateral shearing started to form during Paleogene, and the peak deformation happen around 40 Ma due to the change of the subduction direction of Pacific Plate relative to Eurasia Plate. The NE-striking normal faults are the main structure, and the pre-existing NNE-striking strike-slip faults changed from left-lateral to right-lateral. (4) The fourth transition saw the regional subsidence during Neogene, which was probably caused by the India-Asia "Hard collision" between 25 and 20 Ma.

  8. [The Teachers' Right to Strike Versus the Students' Right to an Education.

    Science.gov (United States)

    Powell, Edward M.

    The speaker establishes himself in opposition to teacher strikes, outlines the scope of teacher strikes, discusses arguments for and against the right of teachers to strike, presents the kinds of strikes that are possible, outlines what a board and the administration can do to head off a strike, and presents the American Association of School…

  9. Isolated Sensorineural Hearing Loss as a Sequela after Lightning Strike

    Directory of Open Access Journals (Sweden)

    Mahfuz Turan

    2015-01-01

    Full Text Available In most of the surviving patients after a lightning strike, audiovestibular abnormalities have been reported. The most frequently reported type of abnormalities is a tympanic membrane perforation with hearing loss and external ear canal burn. However a sensor neural hearing loss and mixed type hearing loss can also occur, but these occur rarely. A nineteen-year-old female patient had, after a lightning strike, serious burns on the left ear, behind the ear, and on the chest and neck. She also had in her left ear 108 dB hearing loss with irregular central perforation and in her right ear 52 dB sensorineural hearing loss. There was no hearing loss before the strike. A hearing aid was recommended for the right ear and good care and follow-up were recommended for the left ear. A lightning strike can cause serious audiological damage. Therefore, it is necessary to make a careful audiovestibular evaluation of the patients. Although there exist rarely healed cases from sensorineural hearing loss after lightning strike in literature, in our case hearing loss occurred bilaterally and then it healed unilaterally. This condition is quite rare in literature.

  10. Integration of geophysical and geological data for delimitation of mineralized zones in Um Naggat area, Central Eastern Desert, Egypt

    Directory of Open Access Journals (Sweden)

    Ibrahim Gaafar

    2015-06-01

    Interpretations of the aeromagnetic maps delineated four regional structural trends oriented due NNW, NW, ENE and E–W directions. They are identified as strike-slip faults, which coincide well with field observations, where NW-trending faults cut and displace right laterally ENE-trending older ones. The interaction between these two strike-slip fault systems confining the albite granite is easily identified on the regional data presenting longer wavelength anomalies, implying deep-seated structures. They could represent potential pathways for migration of enriched mineralized fluids. Geochemically, albite granites of peraluminous characteristics that had suffered extensive post-magmatic metasomatic reworking, resulted into development of (Zr, Hf, Nb, Ta, U, Th, Sn and albite-enriched and greisenized granite body of about 600 m thick, and more than 3 km in strike length. The albite granite is characterized by sharp increase in average rare metal content: Zr (830 ppm, Hf (51 ppm, Nb (340 ppm, Ta (44 ppm, and U (90 ppm. Thorite, uranothorite, uraninite and zircon are the main uranium-bearing minerals of magmatic origin within the enclosing granite. However, with respect to Zr, Nb, and Ta, the albitized granite can be categorized as rare metal granite. The integration of airborne geophysical (magnetic and γ-ray spectrometric, geological, geochemical and mineralogical data succeeded in assigning the albite granite of Um Naggat pluton as a mineralized zone. This zone is characterized by its high thorium and uranium of hydrothermal origin as indicated by its low Th/U ratio, with rare metals mineralization controlled by two main structural trends in the NW- and ENE-directions.

  11. Predicting timing of foot strike during running, independent of striking technique, using principal component analysis of joint angles.

    Science.gov (United States)

    Osis, Sean T; Hettinga, Blayne A; Leitch, Jessica; Ferber, Reed

    2014-08-22

    As 3-dimensional (3D) motion-capture for clinical gait analysis continues to evolve, new methods must be developed to improve the detection of gait cycle events based on kinematic data. Recently, the application of principal component analysis (PCA) to gait data has shown promise in detecting important biomechanical features. Therefore, the purpose of this study was to define a new foot strike detection method for a continuum of striking techniques, by applying PCA to joint angle waveforms. In accordance with Newtonian mechanics, it was hypothesized that transient features in the sagittal-plane accelerations of the lower extremity would be linked with the impulsive application of force to the foot at foot strike. Kinematic and kinetic data from treadmill running were selected for 154 subjects, from a database of gait biomechanics. Ankle, knee and hip sagittal plane angular acceleration kinematic curves were chained together to form a row input to a PCA matrix. A linear polynomial was calculated based on PCA scores, and a 10-fold cross-validation was performed to evaluate prediction accuracy against gold-standard foot strike as determined by a 10 N rise in the vertical ground reaction force. Results show 89-94% of all predicted foot strikes were within 4 frames (20 ms) of the gold standard with the largest error being 28 ms. It is concluded that this new foot strike detection is an improvement on existing methods and can be applied regardless of whether the runner exhibits a rearfoot, midfoot, or forefoot strike pattern. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. VARIATION OF STRIKE INCENTIVES WITH DAMAGE PREFERENCES; FINAL

    International Nuclear Information System (INIS)

    G. CANAVAN

    2001-01-01

    For START III level forces, strike allocations and magnitudes vary little with L, but first strike costs vary directly with L, which means that for K reflecting a preference for the survival of high value targets over their destruction and a preference for high value over military targets, the costs of action are far greater than those of inaction for a wide range of values of damage preference L. Thus, if both sides have much greater preferences for the survival of their high value targets than for military targets or destruction, they do not see a net incentive to strike, and crises are terminated by inaction. Recent decades suggest strong preferences for the survival of high value and that this has contributed to the lack of direct conflict during that period

  13. Comparison of blade-strike modeling results with empirical data

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2004-03-01

    This study is the initial stage of further investigation into the dynamics of injury to fish during passage through a turbine runner. As part of the study, Pacific Northwest National Laboratory (PNNL) estimated the probability of blade strike, and associated injury, as a function of fish length and turbine operating geometry at two adjacent turbines in Powerhouse 1 of Bonneville Dam. Units 5 and 6 had identical intakes, stay vanes, wicket gates, and draft tubes, but Unit 6 had a new runner and curved discharge ring to minimize gaps between the runner hub and blades and between the blade tips and discharge ring. We used a mathematical model to predict blade strike associated with two Kaplan turbines and compared results with empirical data from biological tests conducted in 1999 and 2000. Blade-strike models take into consideration the geometry of the turbine blades and discharges as well as fish length, orientation, and distribution along the runner. The first phase of this study included a sensitivity analysis to consider the effects of difference in geometry and operations between families of turbines on the strike probability response surface. The analysis revealed that the orientation of fish relative to the leading edge of a runner blade and the location that fish pass along the blade between the hub and blade tip are critical uncertainties in blade-strike models. Over a range of discharges, the average prediction of injury from blade strike was two to five times higher than average empirical estimates of visible injury from shear and mechanical devices. Empirical estimates of mortality may be better metrics for comparison to predicted injury rates than other injury measures for fish passing at mid-blade and blade-tip locations.

  14. [Force-feeding of hunger-striking prisoners].

    Science.gov (United States)

    Glick, Shimon

    2014-09-01

    In contrast to the position of the World Medical Association and the Ethics Council of the Israel Medical Association, the author argues for forced-feeding of hunger-striking prisoners when their condition reaches a stage of danger of death or permanent injury. This position is based on the priority of human life over autonomy, and of a communitarian ethic. This position is supported by a District Court decision ordering the feeding of a hunger-striking prisoner, by a Supreme Court decision imposing surgery on a non-consenting prisoner, and in line with Israel's Patient's Right Law.

  15. Sound Quality and Striking Position of a Conga Drum

    Directory of Open Access Journals (Sweden)

    Dylan Harvey

    2014-12-01

    Full Text Available The relationship between the location at which a drum membrane was struck and the quality of sound produced was investigated by striking the drum at several distances between the center and the rim. Through analyzing the harmonics of the wave produced from the impact, it was shown that as the striking location changes, the relative amplitudes of different modes of vibration also changes. It was found that sound of a higher pitch is produced at the rim of the drum than anywhere else on the drum head due to higher modes of vibration becoming dominant.

  16. MORE THAN A LABOR DISPUTE: THE PATCO STRIKE OF 1981

    Directory of Open Access Journals (Sweden)

    Paul L. Butterworth

    2005-01-01

    Full Text Available On August 3, 1981, 13,000 air traffic controllers walked off the job. Under US law, the strike was illegal. President Ronald Reagan ordered the strikers as a group to return to work; when they did not, he ordered individual strikers to return, and again they refused. Two days later the president fired the strikers. Reagan's action transformed relations between organized labor and American management, and created the worst turbulence to hit the American airways in recent history. “More Than a Labor Dispute” examines the work stoppage and aftermath through the eyes of two controllers and a pilot, all of whom worked during the strike.

  17. Remarkable rates of lightning strike mortality in Malawi.

    Science.gov (United States)

    Mulder, Monique Borgerhoff; Msalu, Lameck; Caro, Tim; Salerno, Jonathan

    2012-01-01

    Livingstone's second mission site on the shore of Lake Malawi suffers very high rates of consequential lightning strikes. Comprehensive interviewing of victims and their relatives in seven Traditional Authorities in Nkhata Bay District, Malawi revealed that the annual rate of consequential strikes was 419/million, more than six times higher than that in other developing countries; the rate of deaths from lightning was 84/million/year, 5.4 times greater than the highest ever recorded. These remarkable figures reveal that lightning constitutes a significant stochastic source of mortality with potential life history consequences, but it should not deflect attention away from the more prominent causes of mortality in this rural area.

  18. Strain Variation in Accretionary Prisms Across Space and Time: Insights from the Makran Subduction Zone

    Science.gov (United States)

    Penney, C.; Tavakoli, F.; Saadat, A.; Nankali, H. R.; Sedighi, M.; Khorrami, F.; Sobouti, F.; Rafi, Z.; Copley, A.; Jackson, J. A.; Priestley, K. F.

    2017-12-01

    The Makran is one of the world's least-studied subduction zones. In particular, little is known about the accumulation and accommodation of strain in the onshore part of the subduction zone, which parallels the coasts of southern Iran and Pakistan. The deformation of the Makran accretionary prism results from both its subduction zone setting and N-S right-lateral shear between central Iran and Afghanistan. North of the Makran, this shear is accommodated by a series of right-lateral faults which offset the rocks of the Sistan Suture Zone, an abandoned accretionary prism. However, these right-lateral faults are not observed south of 27°N, and no major N-S faults cut the E-W trending structures of the Makran. How this right-lateral motion is accommodated at the southern end of the Sistan Suture Zone is a long-standing tectonic question. By combining results from geomorphology, GPS, seismology and modelling we conclude that right-lateral motion is transferred across the depression north of the accretionary prism to the region of right-lateral shear at the western end of the accretionary prism. This requires the Jaz Murian depression to be bounded by normal faults, consistent with the basin geomorphology. However, GPS data show compression across the margins of the basin, and no shallow normal-faulting earthquakes have been observed in the region. We therefore suggest that the behaviour of these faults may be time-dependent and controlled by the megathrust seismic cycle, as has been suggested elsewhere (e.g. Chile). Recent strike-slip earthquakes, including the 2013 Balochistan earthquake, have clustered at the prism's lateral edges, showing the importance of spatial, as well as temporal, variations in strain. These earthquakes have reactivated thrust faults in the Makran accretionary prism, showing that the style of strain within accretionary prisms can vary on multiple timescales and allowing us to calculate the coefficient of friction on the underlying megathrust.

  19. EDITORIAL Plagiarism - time to strike at the epidemic

    African Journals Online (AJOL)

    admin

    Plagiarism - time to strike at the epidemic. Lukman Yusuf1, Abraham Aseffa2. We live in a globalized world where information is instantly shared across continents. The number of biomedical journals available for reference is quite enormous and there is a sudden huge surge of free open access journals in the last few years ...

  20. The Eastern Pacific Tropical Cyclone Strike Probability Program (EPSTRKP).

    Science.gov (United States)

    1980-08-01

    of nine preselected points of interest. Although subject to change the points currently listed within the program are: Acapulco, Mazatlan, Puerto ... Vallarta , La Paz, San Diego, Hilo, Honolulu, Johnston Island and Midway Island. The strike probabilities, computed upon receipt of each 6-hourly warning

  1. Effects of Union Organization on Strike Incidence in EU Companies

    NARCIS (Netherlands)

    Jansen, Giedo

    2014-01-01

    The author reinvestigates the relationship between the organizational power of trade unions and strikes based on data from the European Company Survey 2009 (ECS-2009) and the Institutional Characteristics of Trade Unions, Wage Setting, State Intervention and Social Pacts (ICTWSS) database, which

  2. Monte Carlo Simulation to Estimate Likelihood of Direct Lightning Strikes

    Science.gov (United States)

    Mata, Carlos; Medelius, Pedro

    2008-01-01

    A software tool has been designed to quantify the lightning exposure at launch sites of the stack at the pads under different configurations. In order to predict lightning strikes to generic structures, this model uses leaders whose origins (in the x-y plane) are obtained from a 2D random, normal distribution.

  3. Torts Liability for Strike Action and Third Party Rights.

    Science.gov (United States)

    Raday, Frances

    1979-01-01

    Studies the nature of the torts liability incurred in strikes and the extent of existing immunities bestowed on strikers and their organizers, and explores the principles that should govern liability and immunity. Available from Israel Law Review Association, c/o Faculty of Law, Hebrew University of Jerusalem, Mount Scopus, P.O.B. 24100, Jerusalem…

  4. Nurses need the right to strike to protect patients.

    Science.gov (United States)

    Harrison, Malcolm

    2012-04-25

    Four of your readers panellists were asked if the RCN should be affiliated to the Trades Union Congress (reflections April 4). One of them said the RCN needs to modernise and join the wider trade union movement, but 'should keep the "no strike" policy that has always served it so well'.

  5. Analysis of the effects of frequent strikes on academic performance ...

    African Journals Online (AJOL)

    The history of Academic Staff Union of Universities (ASUU)'s strike can be traced back to 1978, the period of the beginning of the decline in the oil boom, when the country faced the consequences of the failure by its rulers to use the oil wealth to generate production and a social welfare system. Military dictatorship had ...

  6. On Striking for a Bargain between Two Completely Informed Agents

    NARCIS (Netherlands)

    Houba, H.E.D.; Wen, Q.

    2007-01-01

    This paper provides a thorough equilibrium analysis of a wage contract negotiation model where the union must choose between strike and holdout between offers and counter-offers. When the union and the firm have different discount factors, delay in reaching an agreement may Pareto dominate many

  7. BIRD/WILDLIFE STRIKE CONTROL FOR SAFER AIR ...

    African Journals Online (AJOL)

    Osondu

    2012-06-05

    Jun 5, 2012 ... These include staff training and retraining, developing good data bank based on .... wildlife is very important in bird control. Successful habitat ... Designated staff patrols the airside areas using chemical repellants, propane cannons, distress call. Birds/Wildlife Strikes Control for Safer Air .................Usman et ...

  8. LAW AND ETHICS OF STRIKES IN THE NIGERIAN HEALTH SYSTEM

    African Journals Online (AJOL)

    2014-10-06

    Oct 6, 2014 ... MDCN Code of ethics intends to give right for cessation of work by workers in the health sector of the economy. Thus under the Common Law, a strike, especially in the essential services is a breach of the contract of employment. The Trade. Union (amendment) Act (Federal Republic of. Nigeria, 2005) ...

  9. Growth control of kalanchoe cultivars Rako and Gold Strike by ...

    African Journals Online (AJOL)

    This study was conducted to test the potential of paclobutrazol and uniconazole used at the propagation stage as a plant growth retardant (PGR) of kalanchoe cultivars Rako and Gold Strike. Three node terminal cuttings were soaked in 500 mL of 0.05, 0.25, or 0.50 mg·L-1 paclobutrazol or uniconazole solution for 2 h.

  10. Striking Inside Angola with 32 Battalion | Scheepers | Scientia ...

    African Journals Online (AJOL)

    Scientia Militaria: South African Journal of Military Studies. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 42, No 1 (2014) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Striking Inside Angola with 32 ...

  11. Force, reaction time, and precision of Kung Fu strikes.

    Science.gov (United States)

    Neto, Osmar Pinto; Bolander, Richard; Pacheco, Marcos Tadeu Tavares; Bir, Cynthia

    2009-08-01

    The goal was to compare values of force, precision, and reaction time of several martial arts punches and palm strikes performed by advanced and intermediate Kung Fu practitioners, both men and women. 13 Kung Fu practitioners, 10 men and three women, participated. Only the men, three advanced and seven intermediate, were considered for comparisons between levels. Reaction time values were obtained using two high speed cameras that recorded each strike at 2500 Hz. Force of impact was measured by a load cell. For comparisons of groups, force data were normalized by participant's body mass and height. Precision of the strikes was determined by a high speed pressure sensor. The results show that palm strikes were stronger than punches. Women in the study presented, on average, lower values of reaction time and force but higher values of precision than men. Advanced participants presented higher forces than intermediate participants. Significant negative correlations between the values of force and precision and the values of force and reaction time were also found.

  12. High tsunami risk at northern tip of Sumatra as a result of the activity of the Sumatra Fault Zone (SFZ) combined with coastal landslides

    Science.gov (United States)

    Haridhi, H. A.; Huang, B. S.; Wen, K. L.; Mirza, A.; Rizal, S.; Purnawan, S.; Fajri, I.; Klingelhoefer, F.; Liu, C. S.; Lee, C. S.; Wilson, C. R.

    2017-12-01

    The lesson learned from the 12 January 2010, Mw 7.0 Haiti earthquake has shown that an earthquake with strike-slip faulting can produce a significant tsunami. This occasion is rare since in the fact of the fault consist predominantly of lateral motion, which is rarely associated with significant uplift or tsunami generation. Yet, another hint from this event, that this earthquake was accompanied by a coastal landslide. Again, there were only few records of a submarine slides as a primary source that generate a tsunami. Hence, the Haiti Mw 7.0 earthquake was generated by these combined mechanisms, i.e. strike-slip faulting earthquake and coastal landslide. In reflecting this event, the Sumatra region exhibit almost identical situation, where the right lateral strike-slip faulting of Sumatra Fault Zone (SFZ) is located. In this study, we are focusing at the northern tip of SFZ at Aceh Province. The reason we focused our study at its northern tip is that, since the Sumatra-Andaman mega earthquake and tsunami on 26 December 2004, which occurred at the subduction zone, there were no records of significant earthquake along the SFZ, where at this location the SFZ is divided into two faults, i.e. Aceh and Seulimeum faults. This study aimed as a mitigation effort, if an earthquake happened at these faults, do we observe a similar result as that happened at Haiti or not. To do so, we access the high-resolution shallow bathymetry data that acquired through a Community-Based Bathymetric Survey (CBBS), examines five scanned Single Channel Seismic (SCS) reflections data, perform the slope stability analysis and that simulate the tsunami using Cornell Multi-grid Coupled Tsunami Model (COMCOT) model with a combined source of fault activity and submarine landslide. The result shows that, by these combined mechanisms, if the earthquake as large as 7 Mw or larger, it could produce a tsunami as high as 6 meters along the coast. The detailed shallow bathymetric and the slope stability

  13. Case Report: Mass Casualty Lightning Strike at Ranger Training Camp.

    Science.gov (United States)

    Thompson, Shannon N; Wilson, Zachary W; Cole, Christopher B; Kennedy, Andrew R; Aycock, Ryan D

    2017-05-01

    Although lightning strikes are a rare occurrence, their significance cannot be ignored given military operations in the field during all types of weather. With proper medical management, patients with lightning injuries can return to duty. Information for this case report comes from eyewitness account at the 6th Ranger Training Battalion and from review of physician documentation from the 96th Medical Group, Eglin Air Force Base, Florida. A lightning strike injured 44 Ranger School participants during a training exercise on August 12, 2015, at Camp Rudder, Florida. These patients were triaged in the field and transported to emergency department of Eglin Air Force Base. Of the 44 casualties, 20 were admitted. All were returned to duty the following day. One patient had cardiac arrest. This patient, along with two others, was admitted to the intensive care unit. Seventeen other patients were admitted for observation for rhabdomyolysis and/or cardiac arrhythmias. One patient was admitted with suspected acute kidney injury indicated by an elevated creatinine. All patients, including those admitted to the intensive care unit, were released on the day following the lightning strike without restrictions and were allowed to return to duty with increased medical monitoring. This case report highlights the need for proper triage and recognition of lightning strike injury, coordination of care between field operations and emergency department personnel, and close follow-up for patients presenting with lightning injury. Symptoms, physical exam, and laboratory findings from rigorous training can be difficult to distinguish from those resulting from lightning injury. Secondary injuries resulting from blunt trauma from falls may have been prevented by the use of the lightning strike posture. Further analysis of procedures and standard operating protocols to mitigate risk during thunderstorms may be required to prevent lightning's effects on large groups of military personnel

  14. Management of patients during hunger strike and refeeding phase.

    Science.gov (United States)

    Eichelberger, M; Joray, M L; Perrig, M; Bodmer, M; Stanga, Z

    2014-01-01

    Hunger strikers resuming nutritional intake may develop a life-threatening refeeding syndrome (RFS). Consequently, hunger strikers represent a core challenge for the medical staff. The objective of the study was to test the effectiveness and safety of evidence-based recommendations for prevention and management of RFS during the refeeding phase. This was a retrospective, observational data analysis of 37 consecutive, unselected cases of prisoners on a hunger strike during a 5-y period. The sample consisted of 37 cases representing 33 individual patients. In seven cases (18.9%), the hunger strike was continued during the hospital stay, in 16 episodes (43.2%) cessation of the hunger strike occurred immediately after admission to the security ward, and in 14 episodes (37.9%) during hospital stay. In the refeed cases (n = 30), nutritional replenishment occurred orally, and in 25 (83.3%) micronutrients substitutions were made based on the recommendations. The gradual refeeding with fluid restriction occurred over 10 d. Uncomplicated dyselectrolytemia was documented in 12 cases (40%) within the refeeding phase. One case (3.3%) presented bilateral ankle edemas as a clinical manifestation of moderate RFS. Intensive medical treatment was not necessary and none of the patients died. Seven episodes of continued hunger strike were observed during the entire hospital stay without medical complications. Our data suggested that seriousness and rate of medical complications during the refeeding phase can be kept at a minimum in a hunger strike population. This study supported use of recommendations to optimize risk management and to improve treatment quality and patient safety in this vulnerable population. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Implications of Incessant Strike Actions on the Implementation of Technical Education Programme in Nigeria

    Science.gov (United States)

    Adavbiele, J. A.

    2015-01-01

    This paper was designed to x-ray the implications of incessant strike actions on the implementation of Technical education programme in Nigeria. The paper took an exploratory view on the concept of strike actions in Nigeria with particular references on notable strike actions that have occurred in Nigeria. The types of strike were explained and…

  16. Slip Behavior of the Queen Charlotte Plate Boundary Before and After the 2012, MW 7.8 Haida Gwaii Earthquake: Evidence From Repeating Earthquakes

    Science.gov (United States)

    Hayward, Tim W.; Bostock, Michael G.

    2017-11-01

    The Queen Charlotte plate boundary, near Haida Gwaii, B.C., includes the dextral, strike-slip, Queen Charlotte Fault (QCF) and the subduction interface between the downgoing Pacific and overriding North American plates. In this study, we present a comprehensive repeating earthquake catalog that represents an effective slip meter for both structures. The catalog comprises 712 individual earthquakes (0.3≤MW≤3.5) arranged into 224 repeating earthquake families on the basis of waveform similarity and source separation estimates from coda wave interferometry. We employ and extend existing relationships for repeating earthquake magnitudes and slips to provide cumulative slip histories for the QCF and subduction interface in six adjacent zones within the study area between 52.3°N and 53.8°N. We find evidence for creep on both faults; however, creep rates are significantly less than plate motion rates, which suggests partial locking of both faults. The QCF exhibits the highest degrees of locking south of 52.8°N, which indicates that the seismic hazard for a major strike-slip earthquake is highest in the southern part of the study area. The 28 October 2012, MW 7.8 Haida Gwaii thrust earthquake occurred in our study area and altered the slip dynamics of the plate boundary. The QCF is observed to undergo accelerated, right-lateral slip for 1-2 months following the earthquake. The subduction interface exhibits afterslip thrust motion that persists for the duration of the study period (i.e., 3 years and 2 months after the Haida Gwaii earthquake). Afterslip is greatest (5.7-8.4 cm/yr) on the periphery of the main rupture zone of the Haida Gwaii event.

  17. Neotectonic inversion of the Hindu Kush-Pamir mountain region

    Science.gov (United States)

    Ruleman, C.A.

    2011-01-01

    The Hindu Kush-Pamir region of southern Asia is one of Earth's most rapidly deforming regions and it is poorly understood. This study develops a kinematic model based on active faulting in this part of the Trans-Himalayan orogenic belt. Previous studies have described north-verging thrust faults and some strike-slip faults, reflected in the northward-convex geomorphologic and structural grain of the Pamir Mountains. However, this structural analysis suggests that contemporary tectonics are changing the style of deformation from north-verging thrusts formed during the initial contraction of the Himalayan orogeny to south-verging thrusts and a series of northwest-trending, dextral strike-slip faults in the modern transpressional regime. These northwest-trending fault zones are linked to the major right-lateral Karakoram fault, located to the east, as synthetic, conjugate shears that form a right-stepping en echelon pattern. Northwest-trending lineaments with dextral displacements extend continuously westward across the Hindu Kush-Pamir region indicating a pattern of systematic shearing of multiple blocks to the northwest as the deformation effects from Indian plate collision expands to the north-northwest. Locally, east-northeast- and northwest-trending faults display sinistral and dextral displacement, respectively, yielding conjugate shear pairs developed in a northwest-southeast compressional stress field. Geodetic measurements and focal mechanisms from historical seismicity support these surficial, tectono-morphic observations. The conjugate shear pairs may be structurally linked subsidiary faults and co-seismically slip during single large magnitude (> M7) earthquakes that occur on major south-verging thrust faults. This kinematic model provides a potential context for prehistoric, historic, and future patterns of faulting and earthquakes.

  18. Microseismicity at the North Anatolian Fault in the Sea of Marmara offshore Istanbul, NW Turkey

    Science.gov (United States)

    Bulut, Fatih; Bohnhoff, Marco; Ellsworth, William L.; Aktar, Mustafa; Dresen, Georg

    2009-01-01

    The North Anatolian Fault Zone (NAFZ) below the Sea of Marmara forms a “seismic gap” where a major earthquake is expected to occur in the near future. This segment of the fault lies between the 1912 Ganos and 1999 İzmit ruptures and is the only NAFZ segment that has not ruptured since 1766. To monitor the microseismic activity at the main fault branch offshore of Istanbul below the Çınarcık Basin, a permanent seismic array (PIRES) was installed on the two outermost Prince Islands, Yassiada and Sivriada, at a few kilometers distance to the fault. In addition, a temporary network of ocean bottom seismometers was deployed throughout the Çınarcık Basin. Slowness vectors are determined combining waveform cross correlation and P wave polarization. We jointly invert azimuth and traveltime observations for hypocenter determination and apply a bootstrap resampling technique to quantify the location precision. We observe seismicity rates of 20 events per month for M < 2.5 along the basin. The spatial distribution of hypocenters suggests that the two major fault branches bounding the depocenter below the Çınarcık Basin merge to one single master fault below ∼17 km depth. On the basis of a cross-correlation technique we group closely spaced earthquakes and determine composite focal mechanisms implementing recordings of surrounding permanent land stations. Fault plane solutions have a predominant right-lateral strike-slip mechanism, indicating that normal faulting along this part of the NAFZ plays a minor role. Toward the west we observe increasing components of thrust faulting. This supports the model of NW trending, dextral strike-slip motion along the northern and main branch of the NAFZ below the eastern Sea of Marmara.

  19. Remarkable rates of lightning strike mortality in Malawi.

    Directory of Open Access Journals (Sweden)

    Monique Borgerhoff Mulder

    Full Text Available Livingstone's second mission site on the shore of Lake Malawi suffers very high rates of consequential lightning strikes. Comprehensive interviewing of victims and their relatives in seven Traditional Authorities in Nkhata Bay District, Malawi revealed that the annual rate of consequential strikes was 419/million, more than six times higher than that in other developing countries; the rate of deaths from lightning was 84/million/year, 5.4 times greater than the highest ever recorded. These remarkable figures reveal that lightning constitutes a significant stochastic source of mortality with potential life history consequences, but it should not deflect attention away from the more prominent causes of mortality in this rural area.

  20. Legal questions surrounding hunger strikes by detainees and prisoners.

    Science.gov (United States)

    Strauss, S A

    1991-01-01

    The 'right to die' is not of an absolute character but is subject to definite qualification. There are legal and social interests reflecting profound ethical values which militate against an absolute right on the part of a prisoner to die by means of a hunger strike. The declared policy of the South African authorities is that a prisoner who resorts to a hunger strike may not be subjected to force-feeding. This is in accordance with the 1975 Tokyo Declaration. Unfortunately the Declaration is silent on the question of whether a doctor may provide medical treatment once a hunger striker has reached the point where he is no longer capable of rational thought. In this article it is submitted that a doctor would be legally entitled to do so.

  1. Single Station System and Method of Locating Lightning Strikes

    Science.gov (United States)

    Medelius, Pedro J. (Inventor); Starr, Stanley O. (Inventor)

    2003-01-01

    An embodiment of the present invention uses a single detection system to approximate a location of lightning strikes. This system is triggered by a broadband RF detector and measures a time until the arrival of a leading edge of the thunder acoustic pulse. This time difference is used to determine a slant range R from the detector to the closest approach of the lightning. The azimuth and elevation are determined by an array of acoustic sensors. The leading edge of the thunder waveform is cross-correlated between the various acoustic sensors in the array to determine the difference in time of arrival, AT. A set of AT S is used to determine the direction of arrival, AZ and EL. The three estimated variables (R, AZ, EL) are used to locate a probable point of the lightning strike.

  2. HUNGER STRIKES AND FORCE-FEEDING IN PRISONS

    Directory of Open Access Journals (Sweden)

    Radu-Florin GEAMĂNU

    2016-05-01

    Full Text Available This study will try to give an overview and assess the international and European standards regarding the management of hunger strikes. We will analyse the international and European standards regarding the force-feeding a prisoner on a hunger strike. The paper will focus on the study of the ECtHR judgements regarding the force-feeding of hunger strikers. Also, we will address the U.S. case and the force-feeding of prisoners which is considered to be, in certain cases, an act of torture based on the international human rights standards. To close with, the study will attempt to go through the recent developments in the Romanian legislation, analysing the legislation and its conformity with the European principles and recommendations, bearing in mind the prohibition, in absolute terms, of torture or inhuman or degrading treatment or punishment.

  3. Control of striking velocity by table tennis players.

    Science.gov (United States)

    Marinovic, Welber; Iizuka, Cristina Akiko; Freudenheim, Andrea Michele

    2004-12-01

    This study investigated how 7 skilled table tennis players controlled velocity of a forehand drive stroke when the ball's trajectory, velocity, and spin were modified. They hit a target in response to balls launched under four different conditions. The relative and absolute times used in the backswing phase showed no significant differences among conditions. When subjects hit fastballs, there was a significant change in the time required for them to reach the peak of velocity in the forward swing phase. In addition, players decreased the velocity of their strokes to hit fast-approaching balls. These results indicate that highly skilled table tennis players need to adjust the striking velocity and striking time (relative and absolute) required to reach the peak of velocity in the forward swing phase for these task modifications. Since they used slower movement velocities to hit faster-approaching balls, skilled table tennis players may override this speed-coupling process.

  4. Simulating Bird Strike on Aircraft Composite Wing Leading Edge.

    OpenAIRE

    Ericsson, Max

    2012-01-01

    In this master thesis project the possibility to model the response of a wing when subjected to bird strike using finite elements is analyzed. Since this transient event lasts only a few milliseconds the used solution method is explicit time integration. The wing is manufactured using carbon fiber laminate. Carbon fiber laminates have orthotropic material properties with different stiffness in different directions. Accordingly, there are damage mechanisms not considered when using metal that ...

  5. Striking dynamics and kinetic properties of boxing and MMA gloves

    Directory of Open Access Journals (Sweden)

    Benjamin Lee

    2014-08-01

    Full Text Available With the growing popularity of Mixed Martial Arts (MMA as a competitive sport, questions regarding the dynamic response and properties of MMA gloves arise. High-energy impacts from punches are very similar to boxing yet MMA competition requires the use of 4 oz fingerless glove, compared to the larger full enclosure boxing glove. This work assessed the kinetic properties and strike dynamics of MMA gloves and compared findings with traditional boxing gloves. Gloves mounted on a molded fist were impacted repetitively on an instrumental anvil designed for impact, over a 5 hour period resulting in 10,000 continuous and consistent strikes. Kinetic data from impacts were sampled at the beginning of the data collection and subsequently every 30 minutes (every 1,000 strikes. MMA gloves produced 4-5 times greater peak force and 5 times faster load rate compared to the boxing glove. However, MMA gloves also showed signs of material fatigue, with peak force increasing by 35% and rate of loading increasing by 60% over the duration of the test. Boxing glove characteristics did deteriorate but to a lesser extent. In summary, the kinetic properties of MMA glove differed substantially from the boxing glove resulting in impacts characterized by higher peak forces and more rapid development of force. Material properties including stiffness and thickness play a role in the kinetic characteristics upon impact, and can be inferred to alter injury mechanisms of blunt force trauma.

  6. Source parameters of the Bay of Bengal earthquake of 21 May 2014 and related seismotectonics of 85°E and 90°E ridges

    Science.gov (United States)

    Prakash, Rajesh; Prajapati, Sanjay Kumar; Srivastava, Hari Narain

    2018-01-01

    Source parameters of the Bay of Bengal earthquake of 21 May 2014 have been studied using full waveform inversion. Its source mechanism thus determined the orientation of the strike slip faulting as NW-SE/NE-SW. The occurrence of past earthquakes along the NE-SW nodal plane suggested its preference as the main fault which could result from the transmission of stresses from the Indian plate boundary. High stress drop of this earthquake (216 bar) is attributed to its location in the intraplate region, strike slip faulting and focus in the colder upper mantle. Comparison of the stress drop of deeper focus Hindukush earthquakes with that of the Bay of Bengal earthquake showed a smaller felt radius due to fractured lithosphere in the Himalayas vis-a-vis more efficient propagation of seismic waves in the peninsular region from the source region of this recent earthquake. The seismological evidence presented for the 85°E and 90°E ridges shows the predominance of strike slip faulting with thrusting on both the ridges. Integrating their source mechanism with that of the May 2014 earthquake, it could be inferred that the Bay of Bengal region (excluding Andaman Sumatra subduction zone) is characterised predominantly by strike slip faulting in the region north of latitude 20°N and strike slip with thrusting in the remaining portion.

  7. Continuity of the San Andreas Fault at San Gorgonio Pass

    Science.gov (United States)

    Carena, S.; Suppe, J.

    2002-12-01

    The San Andreas fault at San Gorgonio Pass does not have a clear surface trace and is considered aseismic. Our findings suggest in fact that the existence of a through-going vertical or near-vertical San Andreas fault between Yucaipa and North Palm Springs is highly unlikely. We mapped over 70 faults in the San Gorgonio Pass-San Bernardino Mountains region using the catalog of 43,500 relocated 1975-1998 earthquakes of Richards-Dinger and Shearer (2000). A clustering algorithm was applied to the relocated earthquakes in order to obtain tighter earthquake clouds and thus better-defined fault surfaces. The earthquakes were then imported into Gocad, a 3D modeling software that allowed us to separate earthquakes into coplanar clusters associated with different faults and fault strands and to fit optimized surfaces to them. We also used the catalog of 13,000 focal mechanisms of Hauksson (2000) to confirm the nature of the mapped faults. We were able to constrain the 3D geometry of the San Andreas fault near San Gorgonio Pass from the 3D geometry of the fault network surrounding it. None of these faults show any displacement due to an hypothetical sub-vertical San Andreas. The San Andreas fault must therefore rotate to much shallower dips, or lose its continuity at depths between 3 and 15 km The most likely configuration is the one where the San Andreas fault merges into the shallow-dipping San Gorgonio Pass thrust W of North Palm Springs. Strike-slip motion is taken up by both the thrust (the slip vector on the N. Palm Springs segment is reverse/right-lateral strike-slip) and by a series of NW striking faults in the footwall of the thrust. The W termination of the most active part of the San Gorgonio Pass thrust coincides with one of these footwall faults at depth, and with the south bend in the San Andreas fault strand N of Banning. This boundary also marks a change in the stress field, with a dominant strike-slip regime to the E (and localized thrusting between San

  8. Static stress transfer within the Cephalonia Transfer Fault Zone (CTFZ) during the 2014 seismic sequence in Cephalonia and the 2015 earthquake in Lefkada

    Science.gov (United States)

    Sboras, Sotiris; Chatzipetros, Alexandros; Pavlides, Spyros; Karastathis, Vassilis; Papadopoulos, Gerassimos

    2017-04-01

    The 2014 seismic sequence in Cephalonia and the following 2015 earthquake in Lefkada Islands, Greece, showed that the Cephalonia Transfer Fault Zone (CTFZ), which runs along the western coasts of both islands, comprises a wide fault zone of parallel to sub-parallel fault segments. The January-February 2014 sequence of Cephalonia consisted of three moderate to strong events. According to published focal mechanisms, the first strongest shock (January 26, Mw 6.1) was produced by a W-dipping, oblique (right-lateral reverse) fault, the second (January 26, Mw 5.3) by a ENE-dipping, pure reverse fault and the third by a ESE-dipping, almost pure right-lateral strike slip fault. The November 17 2015 (Mw 6.4) Lefkada earthquake was produced by a WNW-dipping, roughly vertical, almost pure right-lateral strike-slip fault. None of the shocks above produced any direct coseismic ground rupture, while published relocated hypocentral locations for the Cephalonia sequence revealed various depths indicating a complex fault pattern. Based on published seismological, geological and satellite data (i.e. InSAR), the respective seismic sources were modelled in order to calculate the static stress changes i) during the Cephalonia and Lefkada sequences, and ii) after the sequences for the surrounding faults from the Greek Database of Seismogenic Sources (GreDaSS). Results showed that the February 3 2014 Cephalonia fault was variously affected by the rupture of the two January 26 faults. Stress change distribution on the fault plane showed that both stress drop and rise occurred. The November 17 2015 Lefkada fault was slightly loaded after the rupture of the whole Cephalonia fault system due to the great distance. The post-sequence stress changes variously affect the surrounding faults: the southern segment of the CTFZ is relieved from stresses, while the central ones show a mixed situation. The large northern segment, offshore from Lefkada Island, is mainly under stress drop. Stress drop is

  9. PSpice Model of Lightning Strike to a Steel Reinforced Structure

    International Nuclear Information System (INIS)

    Koone, Neil; Condren, Brian

    2003-01-01

    Surges and arcs from lightning can pose hazards to personnel and sensitive equipment, and processes. Steel reinforcement in structures can act as a Faraday cage mitigating lightning effects. Knowing a structure's response to a lightning strike allows hazards associated with lightning to be analyzed. A model of lightning's response in a steel reinforced structure has been developed using PSpice (a commercial circuit simulation). Segments of rebar are modeled as inductors and resistors in series. A program has been written to take architectural information of a steel reinforced structure and 'build' a circuit network that is analogous to the network of reinforcement in a facility. A severe current waveform (simulating a 99th percentile lightning strike), modeled as a current source, is introduced in the circuit network, and potential differences within the structure are determined using PSpice. A visual three-dimensional model of the facility displays the voltage distribution across the structure using color to indicate the potential difference relative to the floor. Clear air arcing distances can be calculated from the voltage distribution using a conservative value for the dielectric breakdown strength of air. Potential validation tests for the model will be presented

  10. Influence of strike object grounding on close lightning electric fields

    Science.gov (United States)

    Baba, Yoshihiro; Rakov, Vladimir A.

    2008-06-01

    Using the finite difference time domain (FDTD) method, we have calculated vertical electric field Ez, horizontal (radial) electric field Eh, and azimuthal magnetic field Hϕ produced on the ground surface by lightning strikes to 160-m- and a 553-m-high conical strike objects representing the Peissenberg tower (Germany) and the CN Tower (Canada), respectively. The fields were computed for a typical subsequent stroke at distances d' from the bottom of the object ranging from 5 to 100 m for the 160-m tower and from 10 to 300 m for the 553-m tower. Grounding of the 160-m object was assumed to be accomplished by its underground basement represented by a 10-m-radius and 8-m-long perfectly conducting cylinder with or without a reference ground plane located 2 m below. The reference ground plane simulates, to some extent, a higher-conducting ground layer that is expected to exist below the water table. The configuration without reference ground plane actually means that this plane is present, but is located at an infinitely large depth. Grounding of the 553-m object was modeled in a similar manner but in the absence of reference ground plane only. In all cases considered, waveforms of Eh and Hϕ are not much influenced by the presence of strike object, while waveforms of Ez are. Waveforms of Ez are essentially unipolar (as they are in the absence of strike object) when the ground conductivity σ is 10 mS/m (the equivalent transient grounding impedance is several ohms) or greater. Thus, for the CN Tower, for which σ ≥ 10 mS/m, the occurrence of Ez polarity change is highly unlikely. For the 160-m tower and for σ = 1 and 0.1 mS/m, waveforms of Ez become bipolar (exhibit polarity change) at d' ≤ 10 m and d' ≤ 50 m, respectively, regardless of the presence of the reference ground plane. The corresponding equivalent transient grounding impedances are about 30 and 50 Ω in the absence of the reference ground plane and smaller than 10 Ω in the presence of the reference

  11. The Diffusion of Strikes: A Dyadic Analysis of Economic Sectors in the Netherlands, 1995–2007

    NARCIS (Netherlands)

    Jansen, Giedo; Sluiter, Roderick; Akkerman, Agnes

    2016-01-01

    This study examines the extent to which strikes diffuse across sectors and to what extent this diffusion of strikes can be explained by similarities and interdependencies between sectors. For this purpose, the authors examine a unique temporally disaggregated and dyadic database on strikes in Dutch

  12. The Right to Strike in Public Employment. Key Issues Series--No. 15. Second Edition, Revised.

    Science.gov (United States)

    Sterret, Grace; Aboud, Antone

    Since the 1960s, the number of strikes by public employees, especially local government employees, has increased, and the number of employees belonging to unions or associations has about tripled. Recently, attention has been focused on strikes by public employees as a result of the strike in 1981 by air traffic controllers and their subsequent…

  13. Causes of falls of hangingwall over gullies adjacent to stabilizing strike pillars

    CSIR Research Space (South Africa)

    Turner, PA

    1987-08-01

    Full Text Available This report discusses the occurrence of falls of ground in strike gullies. Falls of hangingwall over strike gullies on the up-dip side of strike stabilizing pillars in longwall mining systems were investigated. Gullies were examined in both...

  14. Strikes in France and the Netherlands; A Comparison of Labour Market Institutions

    NARCIS (Netherlands)

    Butter, den F.A.G.; Koppes, S.Y.

    2003-01-01

    Strikes as a consequence of labour conflicts occur about 28 times as much in France as in the Netherlands. This paper examines the institutional differences underlying these differences in strike activity. Our empirical analysis shows that strike activity is high in France if workers were successful

  15. Source parameters of the Izmit-Bolu 1999 (Turkey earthquake sequences from teleseismic data

    Directory of Open Access Journals (Sweden)

    E. Louvari

    2001-06-01

    Full Text Available Body waveform modelling and far-field displacement spectral analyses were used to study the source parameters of five of the largest earthquakes of the (Izmit-Bolu Turkey 1999 sequence. The derived source parameters for the August 17, 1999 M W 7.4 event are: strike = 267°, dip = 85°, rake = – 175°, h = 10 km, M 0 = 1.31×10 20 Nm. The length of the fault was found equal to 76 km, the average displacement 6.4 m and the static stress drop 90 bars. The Bolu November 12, 1999 M W 7.1 event has a focal mechanism with strike = 262°, dip = 53°, rake = –177°, h = 12 km, M 0 = 4.71×10 19 Nm, fault length of 56 km, average displacement 2.1 m and average static stress drop 29 bars. The focal mechanisms of three other aftershocks of the Izmit sequence indicate right lateral strike slip motion, as well. The slip vectors of the events studied are in accordance with the GPS velocity vectors, have a mean azimuth of 269° and reveal the extrusion of the Anatolian plate towards the Aegean.

  16. Structural features and seismotectonic implications of coseismic surface ruptures produced by the 2016 M w 7.1 Kumamoto earthquake

    Science.gov (United States)

    Lin, Aiming

    2017-09-01

    Field investigations and analyses of satellite images and aerial photographs reveal that the 2016 M w 7.1 (Mj 7.3) Kumamoto earthquake produced a ˜40-km surface rupture zone striking NE-SW on central Kyushu Island, Japan. Coseismic surface ruptures were characterized by shear faults, extensional cracks, and mole tracks, which mostly occurred along the pre-existing NE-SW-striking Hinagu-Futagawa fault zone in the southwest and central segments, and newly identified faults in the northeast segment. This study shows that (i) the Hinagu-Futagawa fault zone triggered the 2016 Kumamoto earthquake and controlled the spatial distribution of coseismic surface ruptures; (ii) the southwest and central segments were dominated by right-lateral strike-slip movement with a maximum in-site measured displacement of up to 2.5 m, accompanied by a minor vertical component. In contrast, the northeast segment was dominated by normal faulting with a maximum vertical offset of up to 1.75 m with a minor horizontal component that formed graben structures inside Aso caldera; (iii) coseismic rupturing initiated at the jog area between the Hinagu and Futagawa faults, then propagated northeastward into Aso caldera, where it terminated. The 2016 M w 7.1 Kumamoto earthquake therefore offers a rare opportunity to study the relationships between coseismic rupture processes and pre-existing active faults, as well as the seismotectonics of Aso volcano.

  17. Kinematics of Post-obduction Deformation of the Tertiary Ridge at Al-Khod Village (Muscat, Oman

    Directory of Open Access Journals (Sweden)

    Andreas Scharf

    2016-11-01

    Full Text Available Structural investigations in post-obductional Paleocene to Eocene limestones of the Tertiary Ridge reveal a ~1 km long WNW-ESE striking strike-slip fault system within the ridge, consisting of two main sub-parallel, strike-slip faults. Considering the geometry of the Harding Strain Ellipse, the orientation of structures between the two strike-slip faults (e.g., Riedel shears, folds, reverse faults point to left-lateral motion. The abundance of large-scale folds (up to 100 m in wave length and amplitude between the two strike-slip faults led us to the interpretation of transpressive conditions in a first approximation. Moreover, the Tertiary Ridge of the study area consists of three distinct structural domains. The faults of Domain A and C are oriented WNW-ESE, but the trend of the faults in the central Domain B differs by ~10°. The left-lateral strike-slip fault system exists only in Domain B. We propose that the direction of greatest stress during Miocene plate convergence (sigma 1 was oriented 032°/212°. Considering the trend of the strike-slip zone and the orientation of sigma 1, the left-lateral motion must have been transpressive. Sigma 1 is perpendicularly oriented to the domains A and C. Prior to the Miocene D2 compressional event the study area was affected by a D1 extensional event, related to the opening of the Red Sea and the Gulf of Aden or to gravity-driven normal faulting. The D2 compressional/transpressional structures of the Miocene are reactivating the D1 structures of the Oligocene.

  18. Kinematic evolution of the Romanian Carpathians

    Science.gov (United States)

    Linzer, Hans-Gert; Frisch, Wolfgang; Zweigel, Peter; Girbacea, Radu; Hann, Horst-Peter; Moser, Franz

    1998-11-01

    The regional pattern of contraction and extension directions and the evolution of the strain field from Paleogene to Neogene times enabled a reconstruction of the migration path of the Carpathian collision front. The Carpathian nappes were thrust around the Moesian Plate during Paleogene and Early Neogene times and protruded into a small oceanic embayment between the Moesian and European plates. The arc structure of the Carpathian fold-thrust belt was formed in Late Neogene times as a result of the eastward-escaping Tisza-Dacia block, due to N-directed convergence of the Adriatic plate and the retreating subduction of an oceanic slab. Brittle deformation structures in the Romanian Carpathians suggest three tectonic events related to major plate motions: (1) Paleogene to Middle Miocene NE to ENE contraction caused right-lateral curved strike-slip faults; (2) Middle Miocene to Pliocene fan-shaped orientations of contraction directions were caused by right-lateral oblique convergence in the Southern Carpathians, frontal convergence in the southern Eastern Carpathians and left-lateral convergence in the northern Eastern Carpathians; (3) Pleistocene to Holocene general E-W extension and N-S contraction in the Carpathian arc and local ESE-WNW contraction in the Vrancea area is related to the late roll back stage and break-off of the subducted slab in the bend area.

  19. Anomalously high uplift rates along the Ventura-Santa Barbara Coast, California-tectonic implications

    Science.gov (United States)

    Wehmiller, J. F.; Sarna-Wojcicki, A.; Yerkes, R.F.; Lajoie, K.R.

    1979-01-01

    The NW-SE trending segments of the California coastline from Point Arena to Point Conception (500 km) and from Los Angeles to San Diego (200 km) generally parallel major right-lateral strike-slip fault systems. Minor vertical crustal movements associated with the dominant horizontal displacements along these fault systems are recorded in local sedimentary basins and slightly deformed marine terraces. Typical maximum uplift rates during Late Quaternary time are about 0.3 m/ka, based on U-series ages of corals and amino-acid age estimates of fossil mollusks from the lowest emergent terraces. In contrast, the E-W-trending segments of the California coastline between Point Conception and Los Angeles (200 km) parallel predominantly northward-dipping thrust and high-angle reverse faults of the western Transverse Ranges. Along this coast, marine terraces display significantly greater vertical deformation. Amino-acid age estimates of mollusks from elevated marine terraces along the Ventura-Santa Barbara coast imply anomalously high uplift rates of between 1 and 6 m/ka over the past 40 to 100 ka. The deduced rate of terrace uplift decreases from Ventura to Los Angeles, conforming with a similar trend observed by others in contemporary geodetic data. The more rapid rates of terrace uplift in the western Transverse Ranges reflect N-S crustal shortening that is probably a local accommodation of the dominant right-lateral shear strain along coastal California. ?? 1979.

  20. Active faults paragenesis and the state of crustal stresses in the Late Cenozoic in Central Mongolia

    Directory of Open Access Journals (Sweden)

    V. A. Sankov

    2015-01-01

    Full Text Available Active faults of the Hangay-Hentiy tectonic saddle region in Central Mongolia are studied by space images interpretation, relief analysis, structural methods and tectonic stress reconstruction. The study results show that faults activation during the Late Cenozoic stage was selective, and a cluster pattern of active faults is typical for the study region. Morphological and genetic types and the kinematics of faults in the Hangay-Hentiy saddle region are related the direction of the ancient inherited structural heterogeneities. Latitudinal and WNW trending faults are left lateral strike-slips with reverse or thrust component (Dzhargalantgol and North Burd faults. NW trending faults are reverse faults or thrusts with left lateral horizontal component. NNW trending faults have right lateral horizontal component. The horizontal component of the displacements, as a rule, exceeds the vertical one. Brittle deformations in fault zones do not conform with the Pliocene and, for the most part, Pleistocene topography. With some caution it may be concluded that the last phase of revitalization of strike slip and reverse movements along the faults commenced in the Late Pleistocene. NE trending disjunctives are normal faults distributed mainly within the Hangay uplift. Their features are more early activation within the Late Cenozoic and the lack of relation to large linear structures of the previous tectonic stages. According to the stress tensor reconstructions of the last phase of deformation in zones of active faults of the Hangay-Hentiy saddle using data on tectonic fractures and fault displacements, it is revealed that conditions of compression and strike-slip with NNE direction of the axis of maximum compression were dominant. Stress tensors of extensional type with NNW direction of minimum compression are reconstructed for the Orkhon graben. It is concluded that the activation of faults in Central Mongolia in the Pleistocene-Holocene, as well as

  1. Electrical Characterizations of Lightning Strike Protection Techniques for Composite Materials

    Science.gov (United States)

    Szatkowski, George N.; Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Mielnik, John J.

    2009-01-01

    The growing application of composite materials in commercial aircraft manufacturing has significantly increased the risk of aircraft damage from lightning strikes. Composite aircraft designs require new mitigation strategies and engineering practices to maintain the same level of safety and protection as achieved by conductive aluminum skinned aircraft. Researchers working under the NASA Aviation Safety Program s Integrated Vehicle Health Management (IVHM) Project are investigating lightning damage on composite materials to support the development of new mitigation, diagnosis & prognosis techniques to overcome the increased challenges associated with lightning protection on composite aircraft. This paper provides an overview of the electrical characterizations being performed to support IVHM lightning damage diagnosis research on composite materials at the NASA Langley Research Center.

  2. A Probabilistic, Facility-Centric Approach to Lightning Strike Location

    Science.gov (United States)

    Huddleston, Lisa L.; Roeder, William p.; Merceret, Francis J.

    2012-01-01

    A new probabilistic facility-centric approach to lightning strike location has been developed. This process uses the bivariate Gaussian distribution of probability density provided by the current lightning location error ellipse for the most likely location of a lightning stroke and integrates it to determine the probability that the stroke is inside any specified radius of any location, even if that location is not centered on or even with the location error ellipse. This technique is adapted from a method of calculating the probability of debris collisionith spacecraft. Such a technique is important in spaceport processing activities because it allows engineers to quantify the risk of induced current damage to critical electronics due to nearby lightning strokes. This technique was tested extensively and is now in use by space launch organizations at Kennedy Space Center and Cape Canaveral Air Force Station. Future applications could include forensic meteorology.

  3. Migraine strikes as neuronal excitability reaches a tipping point.

    Directory of Open Access Journals (Sweden)

    Marten Scheffer

    Full Text Available Self-propagating waves of cerebral neuronal firing, known as spreading depolarisations, are believed to be at the roots of migraine attacks. We propose that the start of spreading depolarisations corresponds to a critical transition that occurs when dynamic brain networks approach a tipping point. We show that this hypothesis is consistent with current pathogenetic insights and observed dynamics. Our view implies that migraine strikes when modulating factors further raise the neuronal excitability in genetically predisposed subjects to a level where even minor perturbations can trigger spreading depolarisations. A corollary is that recently discovered generic early warning indicators for critical transitions may be used to predict the onset of migraine attacks even before patients are clinically aware. This opens up new avenues for dissecting the mechanisms for the onset of migraine attacks and for identifying novel prophylactic treatment targets for the prevention of attacks.

  4. Precision Strike Training in Lean Manufacturing: A Workplace Literacy Guidebook [and] Final Report on Precision Strike Workplace Literacy Training at CertainTeed Corporation.

    Science.gov (United States)

    National Alliance of Business, Inc., Washington, DC.

    CertainTeed's Precision Strike training program was designed to close the gaps between the current status of its workplace and where that work force needed to be to compete successfully in global markets. Precision Strike included Skills and Knowledge in Lifelong Learning (SKILL) customized, computerized lessons in basic skills, one-on-one…

  5. New active faults on Eurasian-Arabian collision zone: Tectonic activity of Özyurt and Gülsünler faults (Eastern Anatolian Plateau, Van-Turkey)

    Energy Technology Data Exchange (ETDEWEB)

    Dicle, S.; Üner, S.

    2017-11-01

    The Eastern Anatolian Plateau emerges from the continental collision between Arabian and Eurasian plates where intense seismicity related to the ongoing convergence characterizes the southern part of the plateau. Active deformation in this zone is shared by mainly thrust and strike-slip faults. The Özyurt thrust fault and the Gülsünler sinistral strike-slip fault are newly determined fault zones, located to the north of Van city centre. Different types of faults such as thrust, normal and strike-slip faults are observed on the quarry wall excavated in Quaternary lacustrine deposits at the intersection zone of these two faults. Kinematic analysis of fault-slip data has revealed coeval activities of transtensional and compressional structures for the Lake Van Basin. Seismological and geomorphological characteristics of these faults demonstrate the capability of devastating earthquakes for the area.

  6. Researchers investigate submarine faults north of Puerto Rico

    Science.gov (United States)

    Grindlay, N.; Mann, P.; Dolan, J.

    A 23-day marine geophysical expedition in the summer of 1996 revealed a previously unidentified strike-slip fault zone within 60-100 km of the densely populated northern coast of Puerto Rico. The purpose of the expedition, which was held aboard the U.S. research vessel Maurice Ewing, was to map the northeastern portion of the North America Caribbean plate boundary.The 3000-km-long North America-Caribbean plate boundary stretches from Guatemala to the Lesser Antilles arc. The dominantly left-lateral strike-slip boundary accommodates slow (1-2.6 cm/yr) eastward motion of the Caribbean plate relative to North America. Distributed interplate motion in the region generates large earthquakes (Figure 1, inset). In 1976, an M 7.5 left-lateral, strike-slip earthquake in Guatemala killed approximately 23,000 people and left a quarter of the nation's population homeless.

  7. Parameterization of 18th January 2011 earthquake in Dalbadin Region, Southwest Pakistan

    Directory of Open Access Journals (Sweden)

    Shafiq-Ur-Rehman

    2013-12-01

    In the present study the earthquake was relocated using the technique of travel time residuals. Relocated coordinates and depth were utilized to calculate the focal mechanism solution with outcome of a dominant strike slip mechanism, which is contrary to normal faulting. Relocated coordinates and resulting mechanism are more reliable than many reporting agencies as evaluation in this study is augmented by data from local seismic monitoring network of Pakistan. The tectonics in the area is governed by active subduction along the Makran Subduction Zone. This particular earthquake has strike slip mechanism due to breaking of subducting oceanic plate. This earthquake is located where oceanic lithosphere is subducting along with relative movements between Lut and Helmand blocks. Magnitude of this event i.e. Mw = 7.3, re evaluated depth and a previous study of mechanism of earthquake in same region (Shafiq et al., 2011 also supports the strike slip movement.

  8. New active faults on Eurasian-Arabian collision zone: Tectonic activity of Özyurt and Gülsünler faults (Eastern Anatolian Plateau, Van-Turkey)

    International Nuclear Information System (INIS)

    Dicle, S.; Üner, S.

    2017-01-01

    The Eastern Anatolian Plateau emerges from the continental collision between Arabian and Eurasian plates where intense seismicity related to the ongoing convergence characterizes the southern part of the plateau. Active deformation in this zone is shared by mainly thrust and strike-slip faults. The Özyurt thrust fault and the Gülsünler sinistral strike-slip fault are newly determined fault zones, located to the north of Van city centre. Different types of faults such as thrust, normal and strike-slip faults are observed on the quarry wall excavated in Quaternary lacustrine deposits at the intersection zone of these two faults. Kinematic analysis of fault-slip data has revealed coeval activities of transtensional and compressional structures for the Lake Van Basin. Seismological and geomorphological characteristics of these faults demonstrate the capability of devastating earthquakes for the area.

  9. THE EFFECTS OF HEIGHT AND DISTANCE ON THE FORCE PRODUCTION AND ACCELERATION IN MARTIAL ARTS STRIKES

    Directory of Open Access Journals (Sweden)

    Cynthia A. Bir

    2009-11-01

    Full Text Available Almost all cultures have roots in some sort of self defence system and yet there is relatively little research in this area, outside of a sports related environment. This project investigated different applications of strikes from Kung Fu practitioners that have not been addressed before in the literature. Punch and palm strikes were directly compared from different heights and distances, with the use of a load cell, accelerometers, and high speed video. The data indicated that the arm accelerations of both strikes were similar, although the force and resulting acceleration of the target were significantly greater for the palm strikes. Additionally, the relative height at which the strike was delivered was also investigated. The overall conclusion is that the palm strike is a more effective strike for transferring force to an object. It can also be concluded that an attack to the chest would be ideal for maximizing impact force and moving an opponent off balance

  10. Geometry of the Gerede Segment, North Anatolian Fault Zone, Turkey

    Science.gov (United States)

    Caglayan, A.; ISIK, V.

    2012-12-01

    The North Anatolian Fault Zone (NAFZ) is an active dextral strike-slip fault zone in northern Turkey. The NAFZ is approximately 1200 km in length which extends from Karliova in the east and to reach as far as the Gulf of Saros in the west. The NAFZ becomes wider geometry from east to west which are characterized by 9 destructive earthquake of Ms>7 in the 20th century. An earthquake on 1944 February 1 (Ms 7,3) caused 180 km long surface rupture associated with 2-6.5 m of right-lateral slip between Bayramören in the east and Abant Lake in the west along the NAFZ, which is called the Gerede Segment. This study describes internal geometrical characteristics and deformation mechanism of faults with fault surfaces in the Gerede Segment. The faults along the segment variously cut across Mesozoic-Cenozoic basement rocks and Quaternary alluvium deposits. They juxtapose not only different units of basement but also basement rocks and alluvium. We select typical fault surface that have been formed the best exposures in limestone in different locality, which define exhumed main faults along the segment. These faults strike N70°-80°E and dip 50°-85°NW. Slickenlines on these fault surface plunge shallowly to the NE and/or SW. Fault surface include brittle kinematic indicators indicating right-lateral strike-slip displacements. Some typical Riedel shear fractures (R- and P-fractures) around the main faults also show dextral displacements. Along the main faults two main architectural elements including fault core and fault damage zone is typical. The fault damage zones of these faults are characterized by both fault-related fracturing and fluid-assisted deformation processes. Although breccia is common fault rock in fault zones, gouge and cataclasite are seen in variable exposures. We have defined crackle, mosaic and chaotic type breccias using clast-size and clast proportion. Rock fragments within breccias have occurred mm-cm scale from angular to rounded clast. Sub

  11. New insights into the distribution and evolution of the Cenozoic Tan-Lu Fault Zone in the Liaohe sub-basin of the Bohai Bay Basin, eastern China

    Science.gov (United States)

    Huang, Lei; Liu, Chi-yang; Xu, Chang-gui; Wu, Kui; Wang, Guang-yuan; Jia, Nan

    2018-01-01

    As the largest strike-slip fault system in eastern China, the northeast-trending Tan-Lu Fault Zone (TLFZ) is a significant tectonic element contributing to the Mesozoic-Cenozoic regional geologic evolution of eastern Asia, as well as to the formation of ore deposits and oilfields. Because of the paucity of data, its distribution and evolutionary history in the offshore Liaohe sub-basin of the northern Bohai Bay Basin (BBB) are still poorly understood. Investigations of the strike-slip fault system in the western portion of the offshore Liaohe sub-basin via new seismic data provide us with new insights into the characteristics of the Cenozoic TLFZ. Results of this study show that Cenozoic dextral strike-slip faults occurred near the center of the Liaoxi graben in the offshore Liaohe sub-basin; these strike-slip faults connect with their counterparts to the north, the western part of the onshore Liaohe sub-basin, and have similar characteristics to those in other areas of the BBB in terms of kinematics, evolutionary history, and distribution; consequently, these faults are considered as the western branch of the TLFZ. All strike-slip faults within the Liaoxi graben merge at depth with a central subvertical basement fault induced by the reactivation of a pre-existing strike-slip basement fault, the pre-Cenozoic TLFZ. Data suggest that the TLFZ across the whole Liaohe sub-basin comprises two branches and that the Cenozoic distribution of this system was inherited from the pre-Cenozoic TLFZ. This characteristic distribution might be possessed by the whole TLFZ, thus the new understandings about the distribution and evolutionary model of the TLFZ in this study can be inferred in many research fields along the whole fault zone, such as regional geology, ore deposits, petroleum exploration and earthquake hazard.

  12. Effect of public transport strikes on air pollution levels in Barcelona (Spain).

    Science.gov (United States)

    Basagaña, Xavier; Triguero-Mas, Margarita; Agis, David; Pérez, Noemí; Reche, Cristina; Alastuey, Andrés; Querol, Xavier

    2018-01-01

    Public transport strikes can lead to an increase of the number of private vehicle trips, which in turn can increase air pollution levels. We aimed to estimate the change in air pollution concentrations during public transport strikes in the city of Barcelona (Spain). Data on strikes of the metro, train or bus systems were collected from government records (2005-2016). We collected daily concentrations of NOx; particulate matter with an aerodynamic diameter smaller than 10μm (PM10), 2.5μm (PM2.5), and 1μm (PM1); particle number concentration (N); black carbon (BC) and CO from research and official monitoring stations. We fitted linear regression models for each pollutant with the strike indicator as an independent variable, and models were adjusted for day of the week, month, year, and holiday periods. During the study period, there were 208days affected by a strike of the metro (28), train (106) or bus (91) systems. Half of the strikes were partial, most of them were single-day strikes, there was little overlap between strikes of the different transport systems, and all strikes had to comply with mandatory minimal services. When pooling all types of strikes, NOx and BC showed higher levels during strike days in comparison with non-strike days (increase between 4.1% and 7.7%, with higher increases for NO). The increases in these concentrations were more evident during full day and multiday metro strikes. In conclusion, alterations in public transport have consequences on air quality. This highlights the importance of public transport in reducing air pollution concentrations in cities. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The assessment of lethal propeller strike injuries in sea mammals.

    Science.gov (United States)

    Byard, Roger W; Winskog, Calle; Machado, Aaron; Boardman, Wayne

    2012-04-01

    Assessment of injuries in marine mammals may be required to help authorities determine whether human activity was involved. Three cases of marine animal deaths involving propeller blade strikes are reported to demonstrate characteristic features of such cases and diagnostic difficulties that may occur. Case 1: A juvenile New Zealand fur seal (Arctocephalus forsteri) suffered two parallel linear incised wounds of the flank and died following small intestinal herniation. Case 2: An Indo-Pacific bottlenose dolphin neonate (Tursiops aduncus) died from a deeply incised wound of the left side of the head with shattering of the skull and laceration of the underlying brain.Case 3: An adult female Indo-Pacific bottlenose dolphin (T. aduncus) died from two parallel chop wounds to the torso with opening of the thoracic and abdominal cavities with fractures of the ribs and vertebrae. Given that some animals may recover, and that the carcasses of those that are killed may simply not be found or reported, it is impossible to provide an estimate of the incidence of this type of injury amongst wild sea mammals. In cases that do come to forensic attention accurate evaluation of the type of injury may potentially have great medicolegal significance. Post-mortem putrefaction and post-mortem feeding by other sea animals may complicate assessments. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  14. Cellular nonlinear networks for strike-point localization at JET

    Science.gov (United States)

    Arena, P.; Fortuna, L.; Bruno, M.; Vagliasindi, G.; Murari, A.; Andrew, P.; Mazzitelli, G.

    2005-11-01

    At JET, the potential of fast image processing for real-time purposes is thoroughly investigated. Particular attention is devoted to smart sensors based on system on chip technology. The data of the infrared cameras were processed with a chip implementing a cellular nonlinear network (CNN) structure so as to support and complement the magnetic diagnostics in the real-time localization of the strike-point position in the divertor. The circuit consists of two layers of complementary metal-oxide semiconductor components, the first being the sensor and the second implementing the actual CNN. This innovative hardware has made it possible to determine the position of the maximum thermal load with a time resolution of the order of 30 ms. Good congruency has been found with the measurement from the thermocouples in the divertor, proving the potential of the infrared data in locating the region of the maximum thermal load. The results are also confirmed by JET magnetic codes, both those used for the equilibrium reconstructions and those devoted to the identification of the plasma boundary.

  15. Cellular nonlinear networks for strike-point localization at JET

    International Nuclear Information System (INIS)

    Arena, P.; Fortuna, L.; Bruno, M.; Vagliasindi, G.; Murari, A.; Andrew, P.; Mazzitelli, G.

    2005-01-01

    At JET, the potential of fast image processing for real-time purposes is thoroughly investigated. Particular attention is devoted to smart sensors based on system on chip technology. The data of the infrared cameras were processed with a chip implementing a cellular nonlinear network (CNN) structure so as to support and complement the magnetic diagnostics in the real-time localization of the strike-point position in the divertor. The circuit consists of two layers of complementary metal-oxide semiconductor components, the first being the sensor and the second implementing the actual CNN. This innovative hardware has made it possible to determine the position of the maximum thermal load with a time resolution of the order of 30 ms. Good congruency has been found with the measurement from the thermocouples in the divertor, proving the potential of the infrared data in locating the region of the maximum thermal load. The results are also confirmed by JET magnetic codes, both those used for the equilibrium reconstructions and those devoted to the identification of the plasma boundary

  16. New field and geophysical data about transpressional deformation: An improved model for the structural style of Sha Gou fault area in southern Ningxia, northeastern edge of Tibetan Plateau, China

    Science.gov (United States)

    Xia, Lu; Liu, Zhen; Zhao, Haihua; Wang, Jun; Xiang, Peng; Liu, Jingjing; Cui, Hongzhuang; Ji, Jianqing

    2015-11-01

    Situated near the northeastern edge of the Tibetan Plateau, the Sha Gou fault area (SGFA) represents an important area to understand Cenozoic regional interactions between northeastern (NE) Tibetan Plateau and southwestern (SW) Liupan Shan Basin. Within this region, several km-scale arcuate fault systems such as the Lijun fault and the Madong Shan piedmont fault accommodate the transpressive deformation, but their structural style is still controversial. Predecessors regarded these bow-like faults as southwest-dipping thrust systems with large-scale nappes, however, this opinion is not compatible with the new field and geophysical data. In this study, we aim to ascertain the structural pattern of this area based on the analyses of field observation data, interpretation of seismic reflection profiles and two-dimensional gravity forward modeling. According to the present fieldwork, the structural cleavages, low-angle slickenlines, sub-vertical fault surfaces, "ribbon effect" as well as the linear geomorphic features in plane view indicate that these faults belong to a strike-slip system. Newly acquired seismic profiles, characterized by distinct positive flower structures, strongly suggest that this area is again a strike-slip fault system rather than a thrusting system. Furthermore, gravity forward modeling results show that the reverse strike-slip model without large-scale thrust nappes is closer to the present structural style of this area. The gravity forward modeling is an effective method to identify km-scale thrust nappes, which could be used for reference by the structural style analysis in other similar regions. Based on these evidences, a new transpressional shear model for the structural pattern is proposed. The overall structural style of the SGFA is not characterized by large-scale thrust nappes, but is dominated by a transpressional shear system with significant strike-slip faulting. Such a new model can be an additional evidence for the tectonic escape

  17. Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

    Science.gov (United States)

    2016-02-24

    Silver Bullet? Asking the Right Questions About Conventional Prompt Global Strike (Washington, DC: Carneige Endowment for International Peace, 2013), pp...124 James M. Acton, Silver Bullet? Asking the Right Questions About Prompt Global Strike (Washington, DC: Carnegie Endowment for International Peace, 2013), pp. 120-129. ...Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues Amy F. Woolf Specialist in Nuclear Weapons Policy

  18. Vessel Strike of Whales in Australia: The Challenges of Analysis of Historical Incident Data

    Directory of Open Access Journals (Sweden)

    David Peel

    2018-03-01

    Full Text Available Death or injury to whales from vessel strike is one of the primary threats to whale populations worldwide. However, quantifying the rate of occurrence of these collisions is difficult because many incidents are not detected (particularly from large vessels and therefore go unreported. Furthermore, varying reporting biases occur related to species identification, spatial coverage of reports and type of vessels involved. The International Whaling Commission (IWC has compiled a database of the worldwide occurrence of vessel strikes to cetaceans, within which Australia constitutes ~7% (35 reports of the reported worldwide (~471 reports vessel strike records involving large whales. Worldwide records consist largely of modern reports within the last two decades and historical evaluation of ship strike reports has mainly focused on the Northern Hemisphere. To address this we conducted a search of historical national and international print media archive databases to discover reports of vessel strikes globally, although with a focus on Australian waters. A significant number of previously unrecorded reports of vessel strikes were found for both Australia (76 and worldwide (140, resulting in a revised estimate of ~15% of global vessel strikes occurring in Australian waters. This detailed collation and analysis of vessel strike data in an Australian context has contributed to our knowledge of the worldwide occurrence of vessel strikes and challenges the notion that vessel strikes were historically rare in Australia relative to the rest of the world. The work highlights the need to examine historical records to provide context around current anthropogenic threats to marine fauna and demonstrates the importance of formalized reporting structures for effective collation of vessel strike reports. This paper examines the issues and biases in analysis of vessel strike data in general that would apply to any jurisdiction. Using the Australian data as an example

  19. ‘The Nairobi General Strike [1950]: from protest to insurgency’

    OpenAIRE

    Hyde, David

    2002-01-01

    The Nairobi General Strike [1950] was the culmination of Kenya’s post war strike wave and urban upheaval. An unprecedented upsurge occurred with the general strikes in Mombasa [1947] led by the African Workers Federation [A.W.F.] and in Nairobi by the East African Trades Union Congress [E.A.T.U.C.]. While this has been termed and treated as a city wide strike, there is enough evidence to suggest a movement that went some way beyond Nairobi. The extent of the cohesion and reciprocal impacts am...

  20. Operational Functions to Achieve Synergy between Special Operations and Precision Strike

    National Research Council Canada - National Science Library

    Huff, William M

    2005-01-01

    ...). The paper describes the operational functions required from the appointed operational commander and his staff to achieve synergism through the combination of special operations and precision strike...

  1. The Chinese nuclear arsenal and its second-strike capability

    International Nuclear Information System (INIS)

    Cabestan, Jean-Pierre

    2013-03-01

    It is well known that China possesses a second- strike capability, but a great deal of uncertainty persists on the subject. Over the last few years, without officially adjusting its doctrine, China has nonetheless defined its objectives. In April 2010, the People's Liberation Army Daily indicated that China needed such a capability and contended that ballistic missile submarines (SSBNs) would constitute the safest means of delivery. In the same year, the IISS estimated that the People's Liberation Army was in possession of 90 ICBMs (66 ground-based missiles and 24 SLBMs) and 400 IRBM mainly aimed at Taiwan and Japan. The Pentagon's 2012 report proposed 50-75 ICBMs and 80 -120 IRBM and MRBM. While it is established that the People's Liberation Army is developing Jin class submarines (type-094, of which there are currently two in service, which will soon rise to five) and is developing solid-propellant missiles, which could be activated more quickly, not a great deal is known about the progress of these two projects. The JL-2 (7400 km), which is mounted on SSBNs, is still being tested. In parallel, the traditional principle to which China adheres - no first use of nuclear weapons - seems to have been slightly dented. Thus, in January 2011, the Japanese press agency Kyodo (relayed by Stratfor) reported that the People's Liberation Army had lowered the threshold for use of its strategic weapons: it could henceforth envisage a preventive nuclear strike against a nuclear power that had by conventional means destroyed key strategic targets on its territory, such as a nuclear power station, a dam, or a large city, having provided prior warning to the aggressor. But what most worries the U.S. and its Asian allies, particularly the Japanese, is the quasi-total opacity of the Chinese military nuclear programme. While in April 2010, the United States and Russia signed a treaty limiting their number of strategic weapons to 1550 by 2018, China considers

  2. Assessment of performing an MST strike in Tank 21H

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, Michael R.

    2014-09-29

    Previous Savannah River National Laboratory (SRNL) tank mixing studies performed for the Small Column Ion Exchange (SCIX) project have shown that 3 Submersible Mixer Pumps (SMPs) installed in Tank 41 are sufficient to support actinide removal by MST sorption as well as subsequent resuspension and removal of settled solids. Savannah River Remediation (SRR) is pursuing MST addition into Tank 21 as part of the Large Tank Strike (LTS) project. The preliminary scope for LTS involves the use of three standard slurry pumps (installed in N, SE, and SW risers) in a Type IV tank. Due to the differences in tank size, internal interferences, and pump design, a separate mixing evaluation is required to determine if the proposed configuration will allow for MST suspension and strontium and actinide sorption. The author performed the analysis by reviewing drawings for Tank 21 [W231023] and determining the required cleaning radius or zone of influence for the pumps. This requirement was compared with previous pilot-scale MST suspension data collected for SCIX that determined the cleaning radius, or zone of influence, as a function of pump operating parameters. The author also reviewed a previous Tank 50 mixing analysis that examined the ability of standard slurry pumps to suspend sludge particles. Based on a review of the pilot-scale SCIX mixing tests and Tank 50 pump operating experience, three standard slurry pumps should be able to suspend sludge and MST to effectively sorb strontium and actinides onto the MST. Using the SCIX data requires an assumption about the impact of cooling coils on slurry pump mixing. The basis for this assumption is described in this report. Using the Tank 50 operating experience shows three standard slurry pumps should be able to suspend solids if the shear strength of the settled solids is less than 160 Pa. Because Tank 21 does not contain cooling coils, the shear strength could be larger.

  3. Positive Emotions Associated with "Counter-Strike" Game Playing.

    Science.gov (United States)

    Shin, Mirim; Heard, Rob; Suo, Chao; Chow, Chin Moi

    2012-10-01

    Digital game playing engages people for long periods of time. The pleasure offered by digital games may explain the players' consumption of this activity. Games may elicit both positive and negative emotions, which can be measured by encephalography (EEG). The EEG alpha asymmetry index (AI) is different in positive and negative emotions and so may be used to distinguish positive from negative emotions that occur during gaming. We hypothesized that the "Counter-Strike" (CS) game (Valve Software, Bellevue, WA) is pleasurable and demonstrable with a positive EEG AI. Twelve male participants ages 18-30 years underwent EEG recordings continuously during and postgame. EEG was also recorded pregame for control conditions of baseline (sitting on a chair staring at a blank wall), movement (moving fingers on the computer keyboard with a blank screen), sound (listening to the sound of the CS game with a blank screen), and screen (watching the CS game without playing). Self-ratings of emotional responses were completed at pre-, during, and postgame. A significant decrease in the EEG AI was observed under the screen condition compared with baseline, whereas an increase was observed postgame compared with the screen condition. The participants demonstrated a positive EEG AI following the "shoot" events (shoot opponents) and negative emotions after the "being shot" events. Subjective ratings of emotional response indicated happiness during and postgame, but anger and arousal were reported only during the game. The overall results are consistent with the hypothesis that predominantly positive emotional reactions are elicited from playing the CS game and concur with positive subjective ratings of happiness. Future studies may explore the relationship of game pleasure and obsessive game play.

  4. The Kumamoto Mw7.1 mainshock: deep initiation triggered by the shallow foreshocks

    Science.gov (United States)

    Shi, Q.; Wei, S.

    2017-12-01

    The Kumamoto Mw7.1 earthquake and its Mw6.2 foreshock struck the central Kyushu region in mid-April, 2016. The surface ruptures are characterized with multiple fault segments and a mix of strike-slip and normal motion extended from the intersection area of Hinagu and Futagawa faults to the southwest of Mt. Aso. Despite complex surface ruptures, most of the finite fault inversions use two fault segments to approximate the fault geometry. To study the rupture process and the complex fault geometry of this earthquake, we performed a multiple point source inversion for the mainshock using the data on 93 K-net and Kik-net stations. With path calibration from the Mw6.0 foreshock, we selected the frequency ranges for the Pnl waves (0.02 0.26 Hz) and surface waves (0.02 0.12 Hz), as well as the components that can be well modeled with the 1D velocity model. Our four-point-source results reveal a unilateral rupture towards Mt. Aso and varying fault geometries. The first sub-event is a high angle ( 79°) right-lateral strike-slip event at the depth of 16 km on the north end of the Hinagu fault. Notably the two M>6 foreshocks is located by our previous studies near the north end of the Hinagu fault at the depth of 5 9 km, which may give rise to the stress concentration at depth. The following three sub-events are distributed along the surface rupture of the Futagawa fault, with focal depths within 4 10 km. Their focal mechanisms present similar right-lateral fault slips with relatively small dip angles (62 67°) and apparent normal-fault component. Thus, the mainshock rupture initiated from the relatively deep part of the Hinagu fault and propagated through the fault-bend toward NE along the relatively shallow part of the Futagawa fault until it was terminated near Mt. Aso. Based on the four-point-source solution, we conducted a finite-fault inversion and obtained a kinematic rupture model of the mainshock. We then performed the Coulomb Stress analyses on the two foreshocks

  5. Seismicity, focal mechanisms, and stress distribution in the Tres Virgenes volcanic and geothermal region, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Victor; Munguia, Luis [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (Mexico)

    2006-01-15

    In October 1993 we carried out a seismic monitoring in the Tres Virgenes volcanic region in order to record the background seismicity associated with the volcanic structures, the geothermal field and the tectonic features of the area. Hypocenters for 257 microearthquakes were located in the volcanic edifices and along the northwest right-lateral, strike-slip La Virgen fault. Focal depths range from close to the Earth surface to about 8 km. Shallow depths occur mainly in the volcanic edifices. Deeper seismic events occurred outside the volcanic area. The duration magnitudes of the located microearthquakes range between 1 and 3. The Vp/Vs ratio and the low-Q values estimated suggest heterogeneous material properties in the volcanic structures mainly toward the El Azufre fault and the El Aguajito Caldera, where hydrothermal activity has been reported. The P- and T-axes of focal mechanisms for 90 microearthquakes suggest that the region is under N-S compression and E-W extension, in agreement with the regional tectonic stress field of the NW-SE right-lateral strike-slip transform fault system of the Gulf of California. [Spanish] En octubre de 1993 se llevo a cabo un monitoreo sismico en la region volcanica Las Tres Virgenes con el proposito de registrar la actividad sismica asociada a las estructuras volcanicas, al campo geotermico y a la tectonica local. Se localizaron 257 microsismos con hipocentros en los edificios volcanicos y a lo largo de la falla de rumbo, lateral derecha conocida como falla La Virgen. La profundidad focal de los sismos varia desde los muy cercanos a la superficie de la Tierra hasta los 8 km. Las profundidades someras ocurren principalmente en los edificios volcanicos. Los sismos mas profundos ocurren fuera del area volcanica. La magnitud de duracion de los microsismos localizados varia entre 1 y 3. La razon Vp/Vs y los valores bajos de Q que se estimaron en la zona sugieren un material con propiedades heterogeneas bajo las estructuras

  6. Finding the lost segment of the North Anatolian Fault in the Bursa Basin, Turkey

    Science.gov (United States)

    Kutoglu, S. H.; Deguchi, T.; Gundogdu, O.; Seker, D. Z.; Kuscu, S.

    2011-12-01

    After the 1999 Golcuk Mw=7.4, the seismic stress of the North Anatolian Fault has been transferred onto the segments in the Marmara Sea. The NAF is separated to three branches around the Marmara region; one branch runs into the Marmara Sea from the Yalova-Cinarcik location in the north, the second branch runs into the Marmara Sea from the Gemlik location in the south, and the last one goes toward the Bursa basin from the Sakarya-Pamukova location in the lower south. Some researchers consider that the south branch, which experienced the last major earthquake in the year 1064, poses a danger as much as the north branch.For that reason, this study has been conducted for monitoring the fault activities around the Bursa basin. In this respect, the four Palsar data having the best baseline condition have been obtained between the years 2007-2010. The processing of these data have been resulted in significant deformation interferograms for the data pairs of 31st Oct 2007-8th May 2010 and 31st Jan. 2008-24th Dec. 2010. There are seen deformation anomalies in the Bursa basin along 33 km long in E-W direction and 4.5 km long in N-S direction. The shape of the deformation fringes points out that there is a right lateral strike slip fault line passing through the Bursa basin. The geomorphologic characteristics in the region make us think this fault line may connect to the Sakarya-Geyve branch of the North Anatolian Fault system. The maximum amount of the deformation around the fault line has been determined 18 cm in three years. This amount is too much in comparison to 2.2 cm/yr slip rate of the NAF. As the deformation anomalies are investigated in detail a contraction draws attention, overlapping with a right lateral strike slip motion. Consequently, it can precociously be sad that there exits an uplifting combining with the lateral motion. In addition, significant deformation anomalies have been detected on the Gemlik location where the Iznik fault segment reaches the

  7. The Ahar-Varzaghan (Iran) double earthquakes (Mw 6.5 and 6.2) of August 11th, 2012: A seismotectonic interpretation from regional moment tensors and kinematic parameters

    DEFF Research Database (Denmark)

    Donner, Stefanie; Krüger, Frank; Ghods, Abdolreza

    2013-01-01

    and almost nothing is known about active structures so far. Here, GPS velocity records are directed to North-East, while the direction changes to direct North south of the NTF. On 11th of August 2012 the region was surprisingly struck by a shallow Mw 6.5 earthquake with pure right-lateral strike...... earthquakes with ML 2.0 were observed. In the eastern part of the earthquake sequence, along 3/4 of the rupture length, the aftershocks concentrated in a depth of about 14 km. In the western part they became shallower with about 7 km depth. On 7th of November a strong aftershock (Mw 5.4) occurred......) operated by the International Institute of Earthquake Engineering and Seismology (IIEES) in Tehran. For half of the studied aftershocks we obtain pure E-W / N-S oriented strike-slip mechanisms. The other half shows oblique thrust mechanisms with an orientation of NE-SW. The analysed aftershocks are located...

  8. Numerical simulation of the 1976 Ms7.8 Tangshan Earthquake

    Science.gov (United States)

    Li, Zhengbo; Chen, Xiaofei

    2017-04-01

    An Ms 7.8 earthquake happened in Tangshan in 1976, causing more than 240000 people death and almost destroying the whole city. Numerous studies indicated that the surface rupture zone extends 8 to 11 km in the south of Tangshan City. The fault system is composed with more than ten NE-trending right-lateral strike-slip left-stepping echelon faults, with a general strike direction of N30°E. However, recent scholars proposed that the surface ruptures appeared in a larger area. To simulate the rupture process closer to the real situation, the curvilinear grid finite difference method presented by Zhang et al. (2006, 2014) which can handle the free surface and the complex geometry were implemented to investigate the dynamic rupture and ground motion of Tangshan earthquake. With the data from field survey, seismic section, borehole and trenching results given by different studies, several fault geometry models were established. The intensity, the seismic waveform and the displacement resulted from the simulation of different models were compared with the observed data. The comparison of these models shows details of the rupture process of the Tangshan earthquake and implies super-shear may occur during the rupture, which is important for better understanding of this complicated rupture process and seismic hazard distributions of this earthquake.

  9. Structural Evolution of the East Sierra Valley System (Owens Valley and Vicinity, California: A Geologic and Geophysical Synthesis

    Directory of Open Access Journals (Sweden)

    Richard J. Blakely

    2013-04-01

    Full Text Available The tectonically active East Sierra Valley System (ESVS, which comprises the westernmost part of the Walker Lane-Eastern California Shear Zone, marks the boundary between the highly extended Basin and Range Province and the largely coherent Sierra Nevada-Great Valley microplate (SN-GVm, which is moving relatively NW. The recent history of the ESVS is characterized by oblique extension partitioned between NNW-striking normal and strike-slip faults oriented at an angle to the more northwesterly relative motion of the SN-GVm. Spatially variable extension and right-lateral shear have resulted in a longitudinally segmented valley system composed of diverse geomorphic and structural elements, including a discontinuous series of deep basins detected through analysis of isostatic gravity anomalies. Extension in the ESVS probably began in the middle Miocene in response to initial westward movement of the SN-GVm relative to the Colorado Plateau. At ca. 3–3.5 Ma, the SN-GVm became structurally separated from blocks directly to the east, resulting in significant basin-forming deformation in the ESVS. We propose a structural model that links high-angle normal faulting in the ESVS with coeval low-angle detachment faulting in adjacent areas to the east.

  10. Origin and model of transform faults in the Okinawa Trough

    Science.gov (United States)

    Liu, Bo; Li, Sanzhong; Jiang, Suhua; Suo, Yanhui; Guo, Lingli; Wang, Yongming; Zhang, Huixuan

    2017-06-01

    Transform faults in back-arc basins are the key to revealing the opening and development of marginal seas. The Okinawa Trough (OT) represents an incipient and active back-arc or marginal sea basin oriented in a general NE-SW direction. To determine the strikes and spatial distribution of transform faults in the OT, this paper dissects the NW- and NNE-SN-trending fault patterns on the basis of seismic profiles, gravity anomalies and region geological data. There are three main NW-trending transpressional faults in the OT, which are the seaward propagation of NW-trending faults in the East China Continent. The NNE-SN-trending faults with right-stepping distribution behave as right-lateral shearing. The strike-slip pull-apart process or transtensional faulting triggered the back-arc rifting or extension, and these faults evolved into transform faults with the emergence of oceanic crust. Thus, the transform fault patterns are inherited from pre-existing oblique transtensional faults at the offsets between rifting segments. Therefore, the OT performs the oblique spreading mechanism similar to nascent oceans such as the Red Sea and Gulf of Aden.

  11. Three-dimensional structure and evolution of an asymmetric pull-apart basin

    Science.gov (United States)

    Sagy, Amir; Hamiel, Yariv

    2017-07-01

    The structure of a 250-m-long asymmetrical pull-apart basin developed in carbonate rocks at the Galilee heights, Israel, is herein analyzed. The reconstruction of the basin geometry is based on detailed mapping and LiDAR measurements of fault scarps. The architecture of faults is then used as a boundary condition for calculating the stress pattern in the vicinity of the basin, using a dislocation model. The basin is found to be an asymmetrical V-shaped structure bordered by two longitudinal oblique right-lateral strike-slip faults. The strike of one of the faults is bent at the eastern edge of the basin, generating a transverse boundary fault which joins the second boundary fault orthogonally. The overall lateral displacement is smaller than the basin length, and no transverse or diagonal fault is observed in the western end of the basin. The deformation around the basin is mostly displayed by fractures. Yet, folds and fault branches are observed near the tips of the boundary faults and near kink points of fault segments. Stress analysis obtained by the three-dimensional model is in general agreement with the orientation of fractures and location of high deformation regions in and around the basin. Based on our observations, we present a conceptual model which demonstrates the development of asymmetric basins in releasing bends and sheds light on the structures of similar large pull-apart basins.

  12. Structural evolution of the east Sierra Valley system (Owens Valley and vicinity), California: a geologic and geophysical synthesis

    Science.gov (United States)

    Stevens, Calvin H.; Stone, Paul; Blakely, Richard J.

    2013-01-01

    The tectonically active East Sierra Valley System (ESVS), which comprises the westernmost part of the Walker Lane-Eastern California Shear Zone, marks the boundary between the highly extended Basin and Range Province and the largely coherent Sierra Nevada-Great Valley microplate (SN-GVm), which is moving relatively NW. The recent history of the ESVS is characterized by oblique extension partitioned between NNW-striking normal and strike-slip faults oriented at an angle to the more northwesterly relative motion of the SN-GVm. Spatially variable extension and right-lateral shear have resulted in a longitudinally segmented valley system composed of diverse geomorphic and structural elements, including a discontinuous series of deep basins detected through analysis of isostatic gravity anomalies. Extension in the ESVS probably began in the middle Miocene in response to initial westward movement of the SN-GVm relative to the Colorado Plateau. At ca. 3-3.5 Ma, the SN-GVm became structurally separated from blocks directly to the east, resulting in significant basin-forming deformation in the ESVS. We propose a structural model that links high-angle normal faulting in the ESVS with coeval low-angle detachment faulting in adjacent areas to the east.

  13. Rupture Characteristics of the 25 November 2016 Aketao Earthquake ( M w 6.6) in Eastern Pamir Revealed by GPS and Teleseismic Data

    Science.gov (United States)

    Li, Jie; Liu, Gang; Qiao, Xuejun; Xiong, Wei; Wang, Xiaoqiang; Liu, Daiqin; Sun, Jianing; Yushan, Ailixiati; Yusan, Sulitan; Fang, Wei; Wang, Qi

    2018-02-01

    The 25 November 2016 Aketao, Xinjiang earthquake occurred on the northeastern margin of the Pamir plateau, rupturing the Muji fault on the northern segment of the Kongur Extensional System. We collected coseismic offsets at 7 GPS sites, which show that the fault experienced significate dextral slip with a near-field geodetic displacement of up to 12 cm along the strike. The joint inversion of GPS data and teleseismic P waveforms suggests a complex rupture pattern characterized by the unilateral propagation slip from the epicenter to the southeast for 60 km with a total seismic moment of 1.3 × 1019 Nm, corresponding to a magnitude of M w 6.7 earthquake. Our model of slip distribution shows two major slip patches with a slip amplitude up to 0.6 m, one located at shallow depths of 0-8 km close to the hypocenter with apparent surface breaks and the other, 40 km to the southeast, buried at a greater depth of 12 km. The rupture is dominated by a right-lateral strike slip with significant normal-slip components. The near-field GPS data enhances the spatial resolution of source model. Based on the preferred slip model, the static Coulomb Failure Stress change caused by 2016 Aketao earthquake suggests that the unzipped western and eastern ends of Muji fault and the northern segment of Kungai Fault are significantly promoted.

  14. Pre/post-strike atmospheric assessment system (PAAS)

    International Nuclear Information System (INIS)

    Peglow, S. G.; Molitoris, J. D.

    1997-01-01

    The Pre/Post-Strike Atmospheric Assessment System was proposed to show the importance of local meteorological conditions in the vicinity of a site suspected of storing or producing toxic agents and demonstrate a technology to measure these conditions, specifically wind fields. The ability to predict the collateral effects resulting from an attack on a facility containing hazardous materials is crucial to conducting effective military operations. Our study approach utilized a combination of field measurements with dispersion modeling to better understand which variables in terrain and weather were most important to collateral damage predictions. To develop the PAAS wind-sensing technology, we utilized a combination of emergent and available technology from micro-Doppler and highly coherent laser systems. The method used for wind sensing is to probe the atmosphere with a highly coherent laser beam. As the beam probes, light is back-scattered from particles entrained in the air to the lidar transceiver and detected by the instrument. Any motion of the aerosols with a component along the beam axis leads to a Doppler shift of the received light. Scanning in a conical fashion about the zenith results in a more accurate and two-dimensional measurement of the wind velocity. The major milestones in the benchtop system development were to verify the design by demonstrating the technique in the laboratory, then scale the design down to a size consistent with a demonstrator unit which could be built to take data in the field. The micro-Doppler heterodyne system we developed determines absolute motion by optically mixing a reference beam with the return signal and has shown motion sensitivity to better than 1 cm/s. This report describes the rationale, technical approach and laboratory testing undertaken to demonstrate the feasibility and utility of a system to provide local meteorological data and predict atmospheric particulate motion. The work described herein was funded by

  15. The balancing act between the constitutional right to strike and the ...

    African Journals Online (AJOL)

    While the South African Constitution enshrines both children's right to a basic education and teachers' right to strike, conflict between these two often occurs when the way in which teachers' unions conduct strike actions detracts from learners' education. This article identifies the parties affected by industrial action in the ...

  16. Expert Anticipatory Skill in Striking Sports: A Review and a Model

    Science.gov (United States)

    Muller, Sean; Abernethy, Bruce

    2012-01-01

    Expert performers in striking sports can hit objects moving at high speed with incredible precision. Exceptionally well developed anticipation skills are necessary to cope with the severe constraints on interception. In this paper, we provide a review of the empirical evidence regarding expert interception in striking sports and propose a…

  17. Factors affecting defensive strike behavior in Brown Treesnakes (Boiga irregularis) provoked by humans

    Science.gov (United States)

    Spencer, McKayka M.; Lardner, Bjorn; Mazurek, M.J.; Reed, Robert N.

    2015-01-01

    Striking is a typical antipredator defense exhibited by many species of snakes. While trapping Brown Treesnakes (Boiga irregularis) on Guam, we observed that snakes most frequently struck at an approaching person at a site where snakes had been trapped, marked, and handled in the past. Using a combination of between-sites and within-site comparisons, we assessed if the propensity to strike was correlated with capture histories (both recent and long-term), snake size, body condition (a proxy to nutritional stress), sex, or tail condition (broken or intact), while controlling for confounding variables. We confirmed that propensity to strike was higher at the site where we had been conducting capture-mark-recapture for several years. However, we were unable to demonstrate a correlation between striking tendencies and individual recent or long-term capture histories. The only morphological covariate that had an effect on strike propensity was sex, with females striking more often than males. After removing the site effect from our model, we found that snakes missing parts of their tails were more likely to strike than snakes with intact tails. We have yet to identify the factor(s) that cause the pronounced difference across sites in snake propensity to strike, and data from additional sites might help elucidate any geographical patterns.

  18. The dark side of solidarity: social norms and social relations in the aftermath of strikes

    NARCIS (Netherlands)

    Thommes, Kirsten; Akkerman, Agnes; Torenvlied, René; Born, Marieke

    2014-01-01

    This paper studies how employees anticipate change in social relations after a strike in their organisation. We hypothesise that two group norms affect employees' fear that a strike deteriorates the social relations with their colleagues. We distinguish between two different norms associated with a

  19. The dark side of solidarity. The impact of norms on the aftermath of strikes

    NARCIS (Netherlands)

    Thommes, K; Akkerman, A.; Torenvlied, R.

    2014-01-01

    This paper studies how employees anticipate change in social relations after a strike in their organisation. We hypothesise that two group norms affect employees' fear that a strike deteriorates the social relations with their colleagues. We distinguish between two different norms associated with a

  20. Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya.

    Science.gov (United States)

    Lieberman, Daniel E; Castillo, Eric R; Otarola-Castillo, Erik; Sang, Meshack K; Sigei, Timothy K; Ojiambo, Robert; Okutoyi, Paul; Pitsiladis, Yannis

    2015-01-01

    Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces.

  1. The Balancing Act between the Constitutional Right to Strike and the Constitutional Right to Education

    Science.gov (United States)

    Deacon, H. J.

    2014-01-01

    While the South African Constitution enshrines both children's right to a basic education and teachers' right to strike, conflict between these two often occurs when the way in which teachers' unions conduct strike actions detracts from learners' education. This article identifies the parties affected by industrial action in the school context,…

  2. The Implications of Granting New Jersey Teachers the Right to Strike: A Public Policy Statement.

    Science.gov (United States)

    Lisella, Carmine; Schwartz, Patricia

    Strikes are generally accepted as legitimate prerogatives of employees bargaining with employers in the private sector. Two broad questions must be answered when considering whether the right to strike should be granted public employees, including teachers. First, what are the distinctions between the public and private sectors that can reasonably…

  3. Are physicians' strikes ever morally justifiable? A call for a return to ...

    African Journals Online (AJOL)

    Though physicians strike provides an opportunity to generate more knowledge about the process in which legitimacy of an organization can be restored, it meets with a great deal of resistance not only by the public but from within the medical profession. This paper critically examines the legitimacy of strike by medical ...

  4. Major Burn Injury From Lightning Strike: A Case Report and Review ...

    African Journals Online (AJOL)

    BACKGROUND: Lightning has been viewed as a sign of the anger of the “gods” from Greek mythology. Among Yorubas, thunderstorm is regarded as anger from the god of thunder, “Sango” who could strike anybody anywhere to vent his anger at someone who has committed some form of atrocity. When lightning strikes, it ...

  5. Batter's Choice: Lessons for Teaching Tactics in a Modified Striking/Fielding Game

    Science.gov (United States)

    Sinclair, Christina

    2004-01-01

    When played in their standard form, striking/fielding games are often a favorite among elementary students; yet they allow for only limited participation, which is contradictory to quality physical education. This article presents a sequence of lessons leading to Batter's Choice, a modified striking/fielding game, designed to maximize the…

  6. Strike type variation among Tarahumara Indians in minimal sandals versus conventional running shoes

    Directory of Open Access Journals (Sweden)

    Daniel E. Lieberman

    2014-06-01

    Conclusion: These data reinforce earlier studies that there is variation among foot strike patterns among minimally shod runners, but also support the hypothesis that foot stiffness and important aspects of running form, including foot strike, differ between runners who grow up using minimal versus modern, conventional footwear.

  7. A rapid assessment of species-specific bird strike risk at the Kotoka ...

    African Journals Online (AJOL)

    A rapid assessment of species-specific bird strike risk at the Kotoka International Airport in Accra, Ghana. ... We conclude that wildlife management to avert the risk of bird strikes could be successfully achieved by adopting both proactive and reactive measures to reduce the presence of problem species at the aerodrome.

  8. Lightning Strikes and Thunder Claps: The Strategic Bomber and Air Superiority

    Science.gov (United States)

    2012-12-01

    Views November–December 2012 Air & Space Power Journal | 137 Lightning Strikes and Thunder Claps The Strategic Bomber and Air Superiority Maj Wade S...2012 to 00-00-2012 4. TITLE AND SUBTITLE Lightning Strikes and Thunder Claps: The Strategic Bomber and Air Superiority 5a. CONTRACT NUMBER 5b

  9. Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya.

    Directory of Open Access Journals (Sweden)

    Daniel E Lieberman

    Full Text Available Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces.

  10. Labor Conflict on the National Stage: Metaphoric Lenses in Israel's Teachers' Strike

    Science.gov (United States)

    Shenkar, Miriam; Shenkar, Oded

    2011-01-01

    Teachers often embed their labor demands within a broader context to claim high moral ground and build community support. We analyze a recent teachers' strike in Israel, looking at how the strike played out in a country where the challenges of globalization collided with a socialist legacy in the face of an existential threat. The analysis reveals…

  11. InSAR Analysis of the 2011 Hawthorne (Nevada) Earthquake Swarm: Implications of Earthquake Migration and Stress Transfer

    Science.gov (United States)

    Zha, X.; Dai, Z.; Lu, Z.

    2015-12-01

    The 2011 Hawthorne earthquake swarm occurred in the central Walker Lane zone, neighboring the border between California and Nevada. The swarm included an Mw 4.4 on April 13, Mw 4.6 on April 17, and Mw 3.9 on April 27. Due to the lack of the near-field seismic instrument, it is difficult to get the accurate source information from the seismic data for these moderate-magnitude events. ENVISAT InSAR observations captured the deformation mainly caused by three events during the 2011 Hawthorne earthquake swarm. The surface traces of three seismogenic sources could be identified according to the local topography and interferogram phase discontinuities. The epicenters could be determined using the interferograms and the relocated earthquake distribution. An apparent earthquake migration is revealed by InSAR observations and the earthquake distribution. Analysis and modeling of InSAR data show that three moderate magnitude earthquakes were produced by slip on three previously unrecognized faults in the central Walker Lane. Two seismogenic sources are northwest striking, right-lateral strike-slip faults with some thrust-slip components, and the other source is a northeast striking, thrust-slip fault with some strike-slip components. The former two faults are roughly parallel to each other, and almost perpendicular to the latter one. This special spatial correlation between three seismogenic faults and nature of seismogenic faults suggest the central Walker Lane has been undergoing southeast-northwest horizontal compressive deformation, consistent with the region crustal movement revealed by GPS measurement. The Coulomb failure stresses on the fault planes were calculated using the preferred slip model and the Coulomb 3.4 software package. For the Mw4.6 earthquake, the Coulomb stress change caused by the Mw4.4 event increased by ~0.1 bar. For the Mw3.9 event, the Coulomb stress change caused by the Mw4.6 earthquake increased by ~1.0 bar. This indicates that the preceding

  12. Active faults and related Late Quaternary deformation along the Northwestern Himalayan Frontal Zone, India

    Directory of Open Access Journals (Sweden)

    T. Nakata

    2003-06-01

    Full Text Available Numerous newly-identified traces of active faults in the Himalayan foothill zone along the HFF around Chandigarh, in Pinjore Dun, along the piedmont zone of the Lower Siwalik hill front and within the Lower Tertiary hill range reveal the pattern of thrust and strike-slip faulting, striking parallel to the principal structural trend (NNW-SSE of the orogenic belt. The active Chandigarh Fault, Pinjore Garden Fault and Barsar thrust have vertically dislocated, warped and backtilted fluvial and alluvial-fan surfaces made up of Late Pleistocene-Holocene sediments. West- and southwest-facing fault scarplets with heights ranging from 12 to 50 m along these faults suggest continued tectonic movement through Late Pleistocene to recent times. Gentle warping and backtilting of the terraces on the hanging wall sides of the faults indicate fault-bend folding. These active faults are the manifestation of north-dipping imbricated thrust faults branching out from the major fault systems like the Main Boundary Fault (MBF and Himalayan Frontal Fault (HFF, probably merging down northward into a décollement. The Taksal Fault, striking NNW-SSE, shows prominent right-lateral movement marked by lateral offset of streams and younger Quaternary terraces and occupies a narrow deep linear valley along the fault trace. Right stepping along this fault has resulted in formation of a small pull-apart basin. Fault scarplets facing ENE and WSW are the manifestation of dip-slip movement. This fault is an example of slip-partitioning between the strike-slip and thrust faults, suggesting ongoing oblique convergence of the Indian plate and northward migration of a tectonic sliver. Slip rate along the Taksal Fault has been calculated as 2.8 mm/yr. Preliminary trench investigation at the base of the Chandigarh Fault Scarp has revealed total displacement of 3.5 m along a low angle thrust fault with variable dip of 20° to 46° due northeast, possibly the result of one

  13. Multiphase Deformational History, Kinematics, and Segmentation of the Palos Verdes Fault, Offshore Southern California

    Science.gov (United States)

    Brankman, C. M.; Shaw, J. H.

    2005-12-01

    The Palos Verdes Fault (PVF) forms the western boundary of the Los Angeles basin, California, and has one of the highest slip rates in the region, indicating that it may be a source of future large earthquakes. Using a dense grid of petroleum industry seismic reflection data and exploration well logs, we have mapped a series of stratigraphic horizons in San Pedro Bay south of the peninsula that we use to invert for permissible underlying fault geometries and displacements. The PVF is composed of several discrete but related segments which together reflect a complex and multiphase evolution of the fault system. Directly south of the Palos Verdes Peninsula, imaged hanging wall and footwall fault cut-offs indicate that at depths below about 5km the fault dips moderately to the southwest. Furthermore, a thick sequence of eastward-thickening Miocene strata west of the fault suggests that the PVF originally formed as a normal fault during Miocene extension/transtension. Contractional folding of younger strata, as well as structural duplication of the crystalline basement surface, indicates that the normal fault was subsequently inverted during Plio-Pleistocene transpression. In the upper 3-4 km, the fault is nearly vertical, presumably accommodating right-lateral strike-slip displacement. Approximately 20 km southeast of the Peninsula, the PVF changes character across a major geometric segment boundary as a second fault segment emerges and continues trending southeast. The second segment dips northeast and shows increasing reverse displacement along strike to the southeast. Growth strata in the hanging wall and emergent sea-floor folds indicate that contractional deformation began in Pliocene time and continues to the present. The varying geometry and structural character of the PVF along strike reflect the earlier structural elements which have been reactivated to form the present fault geometry. Furthermore, the segmentation of the PVF may impact hazard estimates in

  14. Paleoseismology of the 1966 Varto Earthquake (Ms 6.8) and Structure of the Varto Fault Zone, Eastern Turkey

    Science.gov (United States)

    Isik, V.; Caglayan, A.; Saber, R.; Yesilyurt, N.

    2014-12-01

    Turkey is a region of active faulting and contains several strike-slip fault zones, which have generated both historical and recent large earthquakes. Two active fault zones in Turkey, the North Anatolian Fault Zone (NAFZ) and the East Anatolian Fault Zone (EAFZ), divide the area into the Anatolian micro-plate accommodating WSW-directed movement. The southeastern continuation of the NAFZ is often referred to the Varto Fault Zone (VFZ). The VFZ cuts mainly Pliocene volcano-sedimentary units and/or Quaternary deposits and is characterized by multiple fault strands and multiple, closely spaced, active seismogenic zones. Fault motions in the zone are primarily right-lateral, with a subordinate component of NNW-SSE shortening. Study area is Varto region in which indications of active faulting are very well preserved. We recognized three coseismic ruptures from five trench exposures. It is referred to these as events 1 (youngest) through 3 (oldest). The best evidence of event 3 comes from fault traces and its upward terminations. The major components of this fault are fault core and damage zone. The fault is not just one plane of discontinuity and bifurcates and creates additional slip surfaces, which propagate out of the plane of the original fault. Event 2 and event 1, referring to 1946 and 1966 earthquakes, are characterized primarily by discrete, regularly spaced normal faults with and 55-80 cm and 105-270 cm throws, respectively and geometry of growth strata. The VFZ in the study area include typical structures of strike-slip fault zone. It forms a number of parallel and slightly sub-parallel strands striking N50°-72°W including contractional and extensional brittle structures. Several meters to tens of meters wavelength active folds with ENE-WSW and WNW-ESE trending fold axis. These folds deform the Plio-Quaternary units and show classic asymmetry associated with both a south- and north-vergent fault propagation fold. Meso-scale normal faults are also well

  15. Developing personal values: trainees' attitudes toward strikes by health care providers.

    Science.gov (United States)

    Li, Su-Ting T; Srinivasan, Malathi; Der-Martirosian, Claudia; Kravitz, Richard L; Wilkes, Michael S

    2011-05-01

    Worldwide, health care providers use strikes and job actions to influence policy. For health care providers, especially physicians, strikes create an ethical tension between an obligation to care for current patients (e.g., to provide care and avoid abandonment) and an obligation to better care for future patients by seeking system improvements (e.g., improvements in safety, to access, and in the composition and strength of the health care workforce). This tension is further intensified when the potential benefit of a strike involves professional self-interest and the potential risk involves patient harm or death. By definition, trainees are still forming their professional identities and values, including their opinions on fair wages, health policy, employee benefits, professionalism, and strikes. In this article, the authors explore these ethical tensions, beginning with a discussion of reactions to a potential 2005 nursing strike at the University of California, Davis, Medical Center. The authors then propose a conceptual model describing factors that may influence health care providers' decisions to strike (including personal ethics, personal agency, and strike-related context). In particular, the authors explore the relationship between training level and attitudes toward taking a job action, such as going on strike. Because trainees' attitudes toward strikes continue to evolve during training, the authors maintain that open discussion around the ethics of health care professionals' strikes and other methods of conflict resolution should be included in medical education to enhance professionalism and systems-based practice training. The authors include sample case vignettes to help initiate these important discussions. Copyright © by the Association of American medical Colleges.

  16. Tiechanshan-Tunghsiao anticline earthquake analysis: Implications for northwestern Taiwan potential carbon dioxide storage site seismic hazard

    Directory of Open Access Journals (Sweden)

    Ruey-Juin Rau

    2017-01-01

    Full Text Available We analyze the seismicity and earthquake focal mechanisms beneath the Tiechanshan-Tunghsiao (TCS-TH anticline over the last two decades for seismic hazard evaluation of a potential carbon dioxide storage site in northwestern Taiwan. Seismicity in the TCS-TH anticline indicates both spatial and temporal clustering at a depth range of 7 - 12 km. Thirteen 3.0 ≤ ML ≤ 5.2 earthquake focal mechanisms show a combination of thrust, strike-slip, and normal faulting mechanisms under the TCS-TH anticline. A 1992 ML 5.2 earthquake with a focal depth of ~10 km, the largest event ever recorded beneath the TCS-TH anticline during the last two decades, has a normal fault mechanism with the T-axis trending NNE-SSW and nodal planes oriented NNW-SSE, dipping either gently to the NNE or steeply to the SSW. Thrust fault mechanisms that occurred with mostly E-W or NWW-SEE striking P-axes and strike-slip faulting events indicate NWW-SEE striking P-axes and NNE-SSW trending T-axes, which are consistent with the regional plate convergence direction. For the strike-slip faulting events, if we take the N-S or NNW-SSE striking nodal planes as the fault planes, the strike-slip faults are sinistral motions and correspond to the Tapingting fault, which is a strike-slip fault reactivated from the inherited normal fault and intersects the Tiechanshan and Tunghsiao anticlines.

  17. Collective Labor Disputes and Strikes in Russia: The Impact of Judicial Precedents and Enforcement

    Directory of Open Access Journals (Sweden)

    Elena Gerasimova

    2017-01-01

    Full Text Available The right to strike is recognized in the Constitution and the Labor Code of the Russian Federation as a means to resolve collective labor disputes. However, in Russia labor protests come up for discussion much more frequently than strikes. In recent years the number of labor protests in Russia, including various forms of work stoppage, has increased significantly compared to previous years, but the number of legally constituted collective labor disputes and strikes has remained very low. The legislation on resolution of collective labor disputes and mounting strikes is quite restrictive in Russia, and its enforcement also encourages employees to seek alternative ways to settle collective labor conflicts. There is little empirical research on the judicial implementation of these norms and its influence on the enforcement of legislation. Therefore, this paper analyses the reasoning of courts in cases on the legality of strikes, their interpretations of the law, and the impact these decisions have on the enforcement of the legislation on resolution of collective labor disputes and strikes. Our conclusion is that the courts act as another restrictive influence on the resolution of collective labor disputes and the exercise of the right to strike in Russia.

  18. A simple field method to identify foot strike pattern during running.

    Science.gov (United States)

    Giandolini, Marlène; Poupard, Thibaut; Gimenez, Philippe; Horvais, Nicolas; Millet, Guillaume Y; Morin, Jean-Benoît; Samozino, Pierre

    2014-05-07

    Identifying foot strike patterns in running is an important issue for sport clinicians, coaches and footwear industrials. Current methods allow the monitoring of either many steps in laboratory conditions or only a few steps in the field. Because measuring running biomechanics during actual practice is critical, our purpose is to validate a method aiming at identifying foot strike patterns during continuous field measurements. Based on heel and metatarsal accelerations, this method requires two uniaxial accelerometers. The time between heel and metatarsal acceleration peaks (THM) was compared to the foot strike angle in the sagittal plane (αfoot) obtained by 2D video analysis for various conditions of speed, slope, footwear, foot strike and state of fatigue. Acceleration and kinematic measurements were performed at 1000Hz and 120Hz, respectively, during 2-min treadmill running bouts. Significant correlations were observed between THM and αfoot for 14 out of 15 conditions. The overall correlation coefficient was r=0.916 (Pfoot strike except for extreme forefoot strike during which the heel rarely or never strikes the ground, and for different footwears and states of fatigue. We proposed a classification based on THM: FFS<-5.49ms

  19. Gender frames and collective action: Configurations of masculinity in the Pittston Coal strike

    Energy Technology Data Exchange (ETDEWEB)

    Beckwith, K. [College Wooster, Wooster, OH (United States)

    2001-06-01

    This article develops the concept of gender frame for understanding major transformations in the collective action repertoires of social movements. Focusing on the United Mine Workers of America (UMWA) strike against the Pittston Coal Group (1989-90), the article discusses the UMWA's traditional collective action repertoire and its innovation of nonviolent protest, widely employed during the strike. Interviews with major activists and UMWA staff and officers illustrate how the UMWA employed a gender frame of mining masculinities to initiate the new nonviolent strike action. The article concludes by suggesting how collective action repertoires and framing are linked and encouraging future research on gender frames in social movements.

  20. An Exploratory Analysis of Littoral Combat Ships Ability to Protect Expeditionary Strike Groups

    National Research Council Canada - National Science Library

    Efimba, Motale

    2003-01-01

    ...) to augment or replace the current defenses of Expeditionary Strike Groups (ESG). Specifically, LCS's ability to help defend an ESGs in an anti-access scenario against a high-density small boat attack is simulated. Numbers of CRUDES...

  1. Expeditionary Strike Group: New Label, or New Concept - for Future Naval Warriors of America's Small Wars?

    National Research Council Canada - National Science Library

    Hancock, Daryl

    2003-01-01

    ... as, emergent contingency operations, and major theater wars. In the near future they will accomplish this mission while deployed around the globe under the new concept of Expeditionary Strike Groups (ESG...

  2. Three-dimensional impact kinetics with foot-strike manipulations during running

    Directory of Open Access Journals (Sweden)

    Andrew D. Nordin

    2017-12-01

    Conclusion: Loading rate–time assessment identified contrasting impact characteristics in each direction and the 3D resultant following foot-strike manipulations, with potential implications for lower extremity structures in running.

  3. Personality Characteristics of Pre/Post-Strike Air Traffic Control Applicants

    National Research Council Canada - National Science Library

    Schroeder, David

    1997-01-01

    ...) positions within the Federal Aviation Administration for more than 3 decades. This study was designed to assess the relationship between personality characteristics of a group of post-strike applicants (1984...

  4. Counterproliferation Strategy: The Role of Preventive War, Preventive Strikes, and Interdiction

    National Research Council Canada - National Science Library

    Rak, Claire

    2003-01-01

    This thesis analyzes the potential effectiveness of preventive war, preventive strikes, and interdiction as tools for the United States to counter the proliferation of weapons of mass destruction (WMD...

  5. Wildlife strike risk assessment in several Italian airports: lessons from BRI and a new methodology implementation.

    Directory of Open Access Journals (Sweden)

    Cecilia Soldatini

    Full Text Available The presence of wildlife in airport areas poses substantial hazards to aviation. Wildlife aircraft collisions (hereafter wildlife strikes cause losses in terms of human lives and direct monetary losses for the aviation industry. In recent years, wildlife strikes have increased in parallel with air traffic increase and species habituation to anthropic areas. In this paper, we used an ecological approach to wildlife strike risk assessment to eight Italian international airports. The main achievement is a site-specific analysis that avoids flattening wildlife strike events on a large scale while maintaining comparable airport risk assessments. This second version of the Birdstrike Risk Index (BRI2 is a sensitive tool that provides different time scale results allowing appropriate management planning. The methodology applied has been developed in accordance with the Italian Civil Aviation Authority, which recognizes it as a national standard implemented in the advisory circular ENAC APT-01B.

  6. Electrically conductive carbon fibre-reinforced composite for aircraft lightning strike protection

    Science.gov (United States)

    Katunin, Andrzej; Krukiewicz, Katarzyna; Turczyn, Roman; Sul, Przemysław; Bilewicz, Marcin

    2017-05-01

    Aircraft elements, especially elements of exterior fuselage, are subjected to damage caused by lightning strikes. Due to the fact that these elements are manufactured from polymeric composites in modern aircraft, and thus, they cannot conduct electrical charges, the lightning strikes cause burnouts in composite structures. Therefore, the effective lightning strike protection for such structures is highly desired. The solution presented in this paper is based on application of organic conductive fillers in the form of intrinsically conducting polymers and carbon fabric in order to ensure electrical conductivity of whole composite and simultaneously retain superior mechanical properties. The presented studies cover synthesis and manufacturing of the electrically conductive composite as well as its characterization with respect to mechanical and electrical properties. The performed studies indicate that the proposed material can be potentially considered as a constructional material for aircraft industry, which characterizes by good operational properties and low cost of manufacturing with respect to current lightning strike protection materials solutions.

  7. Annotated Bibliography of Bird Hazards to Aircraft: Bird Strike Committee Citations 1967-1997

    National Research Council Canada - National Science Library

    Short, Jeffrey

    1998-01-01

    .... This annotated bibliography of bird hazards to aircraft, termed ABBHA, is a compilation of citations with abstracts on a wide range of related topics such as bird strike tolerance engineering, bird...

  8. The role of Precambrian mylonitic belts and present-day stress field in the coseismic reactivation of the Pernambuco lineament, Brazil

    Science.gov (United States)

    Ferreira, Joaquim M.; Bezerra, Francisco H. R.; Sousa, Maria O. L.; do Nascimento, Aderson F.; Sá, Jaziel M.; França, George S.

    2008-08-01

    The Pernambuco lineament is a steeply dipping continental-scale ductile shear zone rooted within the Precambrian lithosphere of intraplate northeastern Brazil. It was formed during the Brasiliano orogeny ~ 600 Ma and reactivated during the Pangea breakup in the Cretaceous, when it controlled fault propagation and sediment accumulation in several rift basins. The region is now under an ~ E-W-trending horizontal compression and ~N-S-trending extension, and faulting occurs predominantly in a strike-slip regime. We investigated two aftershock sequences and the preexisting tectonic fabrics along the Pernambuco lineament in order to evaluate the role of these fabrics in the coseismic reactivation of continental-scale structures. The lineaments consist of a main ENE-WSW-trending mylonitic belt about 2-3 km wide, and two secondary NE-trending mylonitic belts about 100 m wide. They both present steeply dipping mylonitic foliations and shallowing plunging stretching lineations. The mylonites present granitoid protoliths and mineral parageneses that range from amphibolite to greenschist facies. Brittle deformation overprints the ductile fabric in all mylonitic belts. In 1991, coseismic reactivation nucleated along the ENE-WSW-striking, ~ 3.3-5.6 km deep, normal fault of less than 1 km in length in the main mylonitic belt. In 2002, seismicity migrated to a NE-trending secondary mylonitic branch and moved as a right-lateral strike-slip, ~ 1.2 km long, 3.8-4.9 km deep fault plane. Both fault segments reactivated the mylonitic foliation and form part of a major system. We conclude that the interplay between the present-day stress field and preexisting fabrics controls seismogenic fault location, attitude, and kinematics. The Pernambuco lineament is an example of a long-lived continental-scale structure, where selective reactivation has occurred. Other shear zones in the region also show a long history of brittle reactivation and present similar orientation in relation to the

  9. Stress Interactions Between the 1976 Magnitude 7.8 Tangshan Earthquake and Adjacent Fault Systems in Northern China

    Science.gov (United States)

    Zhang, Z.; Lin, J.; Chen, Y. J.

    2004-12-01

    The 28 July 1976 ML = 7.8 Tangshan earthquake struck a highly populated metropolitan center in northern China and was one of the most devastating earthquakes in modern history. Its occurrence has significantly changed the Coulomb stresses on a complex network of strike-slip, normal, and thrust faults in the region, potentially heightened the odds of future earthquakes on some of these fault segments. We have conducted a detailed analysis of the 3D stress effects of the Tangshan earthquake on its neighboring faults, the relationship between stress transfer and aftershock locations, and the implications for future seismic hazard in the region. Available seismic and geodetic data, although limited, indicate that the Tangshan main shock sequence is composed of complex rupture on 2-3 fault segments. The dominant rupture mode is right-lateral strike-slip on two adjoining sub-segments that strike N5¡aE and N35¡aE, respectively. We calculated that the Tangshan main shock sequence has increased the Coulomb failure stress by more than 1 bar in the vicinity of the Lunanxian district to the east, where the largest aftershock (ML = 7.1) occurred 15 hours after the Tangshan main event. The second largest aftershock (ML = 6.8) occurred on the Ninghe fault to the southwest of the main rupture, in a transitional region between the calculated Coulomb stress increase and decrease. The majority of the ML > 5.0 aftershocks also occurred in areas of calculated Coulomb stress increase. Our analyses further indicate that the Coulomb stress on portions of other fault segments, including the Leting and Lulong fault to the east and Yejito fault to the north, may also have been increased. Thus it is critical to obtain estimates of earthquake repeat times on these and other tectonic faults and to acquire continuous GPS and space geodetic measurements. Investigation of stress interaction and earthquake triggering in northern China is not only highly societal relevant but also important for

  10. Seismotectonics of the 2010 El Mayor Cucapah - Indiviso Earthquake and its Relation to Seismic Hazard in Southern California

    Science.gov (United States)

    Gonzalez-Garcia, J. J.; Gonzalez Ortega, A.; Bock, Y.; Fialko, Y.; Fielding, E. J.; Fletcher, J. M.; Galetzka, J. E.; Hudnut, K. W.; Munguia, L.; Nelson, S. M.; Rockwell, T. K.; Sandwell, D. T.; Stock, J.

    2010-12-01

    The April 4th, 2010 Mw 7.2 earthquake was the largest earthquake in over 100 years of known historical seismicity in the Salton Trough region. It was a relatively benign earthquake, with only two deaths related to its occurrence. It produced, however, profound agricultural and ecological changes at the southern section of the Mexicali Valley, where a new fault called the Indiviso fault, is shown to have ruptured by analysis of ALOS PALSAR and Landsat imagery. The Indiviso fault connects the ridge-transform and continental transform tectonic regimes with a straight linkage, as revealed by this earthquake, but this event also simultaneously involved oblique normal faulting and cross-faulting. The earthquake was complex, with at least three distinct slip pulses. It originated as a normal rupture along the ~18 km long, N-S striking El Mayor-Hardy fault along the east margin of the Sierra El Mayor. After 10 seconds, two large bursts of energy were released, one to the NW and one to the SE, producing the total moment release equivalent to Mw 7.25. The NW ruptures reactivated portions of the Pescadores, Borrego and Paso Superior faults with minor slip along the Laguna Salada and several other faults. This section had a dominant right lateral strike slip sense of motion with the NE side down. To the SE of the epicenter, disruption occurred along the dominantly strike-slip Indiviso fault, with a SW side down component of dip slip. The epicentral aftershock area, including its main aftershock to the NW, is >120 km in length; the surficial faulting occurs along ~110 km with 6-9 km of splaying to the N-NE at the NW end and to the S-SW at the SE end. The El Mayor Cucapah - Indiviso event follows nine M>6.5 earthquakes along the San Andreas fault system in the past 80 years between the head of the Gulf of California and the Transverse Ranges. Long, straight fault segments capable of larger earthquakes, and that have not ruptured historically, include portions of the San Jacinto

  11. Seismic sequences and swarms in the Latium-Abruzzo-Molise Apennines (central Italy): New observations and analysis from a dense monitoring of the recent activity

    Science.gov (United States)

    Frepoli, A.; Cimini, G. B.; De Gori, P.; De Luca, G.; Marchetti, A.; Monna, S.; Montuori, C.; Pagliuca, N. M.

    2017-08-01

    We present a detailed analysis of the seismic activity in the central Apennines based on a high quality seismogram data set collected from two temporary and three permanent networks. This integrated network recorded, between January 2009 and December 2013, a total of 7011 local earthquakes (6270 selected for this study), with local magnitudes ML ranging from 0.4 to 4.7. Hypocentres were located by using a reference 1D crustal velocity model determined with a genetic algorithm. The majority of the hypocenters are located beneath the axis of the Apenninic belt, while the rest are found along the peri-Tyrrhenian margin. Hypocentral depth distribution extends to a depth of 31 km with a pronounced peak between 8 and 12 km. Both low-to-moderate magnitude seismic sequences and diffuse swarm-like seismicity was observed. There were two major seismic swarms and a seismic sequence, which included the Marsica-Sora ML 4.7 main shock. A total of 468 fault plane solutions were derived from P-wave polarities. This new data set more than quadruples the number of focal mechanisms that was previously available for regional stress field analysis in the study region. The majority of the fault plane solutions in the central Apennines show predominantly normal fault movements, with T-axis trends oriented NE-SW. Focal mechanisms calculated in this study confirm that this area is in extension. For the seismic swarms-sequence in the Marsica-Sora area we also derived the azimuth and plunge of the principal stress axes by inverting fault plane solutions. We find a few right-lateral strike-slip focal mechanisms that possibly identify the prolongation of the strike-slip kinematics in the Gargano-Apulia foreland to the west, and mark the passage to the NW-SE striking normal faults of the inner Apenninic belt. The seismicity and stress distribution we observe might be consistent with a fragmented tectonic scenario in which faults with small dimensions release seismic energy in a diffused way.

  12. Bird Strike Committee Europe (BSCE) , 13th Meeting, Bern, Switzerland 29th May to 2nd June 1978

    National Research Council Canada - National Science Library

    1979-01-01

    ...: Identification of Bird Remains as Part of the Bird Strike Reporting Procedure Birdstrikes - Helicopter in GAF Collisions with Birds of Prey in the Alps The Bird Strike Reporting System in Swiss Air...

  13. The Evolution of Preemptive Strikes in Israeli Operational Planning and Future Implications for the Cyber Domain

    Science.gov (United States)

    2013-05-23

    The strategic and operational use of preemptive strikes has transitioned from the traditional tactic of air raids to the use of covert cyber attacks like...Stuxnet, operational planners can gain an understanding of the evolution of preemption as a concept. Examining this shift from air strikes to cyber ... attacks through the lens of U.S. Army Doctrine and the tenets of Unified Land Operations (Depth, Synchronization, Integration, Adaptability, Flexibility

  14. A numerical model for bird strike on sidewall structure of an aircraft nose

    OpenAIRE

    Liu, Jun; Li, Yulong; Gao, Xiaosheng; Yu, Xiancheng

    2014-01-01

    In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH) and finite element (FE) method to predict the dynamic responses of aircraft structures in bird strike events, bird-strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH–FE method is developed to simulate the bird...

  15. Upward streamers produced by a lightning strike to radio transmission towers

    Science.gov (United States)

    Krider, E. Philip; Wetmore, Ralph H.

    1987-01-01

    A lightning strike to the center of three 78-m radio transmission towers produced upward discharges with lengths of 40 and 79 m from each of the neighboring towers. This strike also caused a number of insulators on guy wires that supported the tower to flash over, and the locations of these points and the two-dimensional geometry of the discharge channels are projected onto a vertical plane that is centered on the tower.

  16. The Left Labourites and the General Strike of 1926 in the UK

    Directory of Open Access Journals (Sweden)

    Evgeniya G. Blosfeld

    2017-12-01

    Full Text Available The author analyses the left labourites’ attitude to the interaction of the Labour Party and trade unions and use of general strike as a means of the social struggle. Besides the article analyses the left labourites’ estimation of 1926 general strike and the causes of the defeat, and the strike of the miners who decided to continue it. The left labourites defended the branch principle of the trade unions’ organization based on the shopstewards’ model which was better adopted for the strike struggle. The left labourites took into account that the general structure of the labour movement would remain the same, but the Labour Party would take over the leadership from trade unions. The left labourites supported the peaceful way of transition to socialism and they considered the general strike to be analogy of social revolution or a means of pressure of the government for nationalization of the main economic branches and the improvement of the workers’ life conditions. Under extreme circumstances, the general strike was considered to be a means to prevent antidemocratic revolution. Evaluating the general strike of 1926, the author marks the absence of unity in the leadership, hesitations and inconsistency of the left labourites themselves. They didn’t give a single proposal about the improvement of the working-class movement organization except of state British Trade Unions Congress. As a result, the criticism of the General Council’s renegade position was bestowed upon the leadership of the Miners Federation who didn’t submit to the General Council order to stop the strike.

  17. The single match approach to strike rate adjustments in batting performance measures in cricket.

    Science.gov (United States)

    Lemmer, Hermanus H

    2011-01-01

    Batting performance measures containing strike rate adjustments take into account the important fact that if two batsmen had scored the same number of runs in a match, the one with the better strike rate had performed best. But match conditions can influence the batting and bowling performances of cricket players. On a good pitch a batsman can get a good score at a high strike rate, but if the pitch was bad, a similar good score is normally accompanied by a much lower strike rate. The main objective of this study is to propose a method that can be used to make batsmen's scores comparable despite the fact that playing conditions might have been very different. The number of runs scored by a batsman is adjusted by comparing his strike rate with the overall strike rate of all the players in the specific match. These adjusted runs are then used in the most appropriate formula to calculate the average of the batsman. The method is illustrated by using the results of the Indian Premier League 2009 Twenty20 Series played during May and June 2009. The main conclusion is that the traditional average is not the most appropriate measure to compare batsmen's performances after conclusion of a short series. Key pointsIt is unfair to compare the score of a batsman obtained on a good pitch under ideal batting conditions with that of a batsman who had to battle under severe conditions.By comparing a batsman's strike rate with the overall strike rate of the players in the specific match, his score can be adjusted to get a better figure for his true performance.The results demonstrate clearly that the use of adjusted scores lead to rankings that differ from those based on the traditional measures.

  18. Carrier Aviation and Hybrid Conflict: The Future of the Strike Fighter

    Science.gov (United States)

    2011-05-01

    Throughout strike fighter squadrons, the TOPGUN manual is the bible, "TOPGUN recommends ... " is the gospel , and Strike Fighter Instructors (SFTI) are the...34. 60 Ibid, 7. 61 Ibid, 34. 62 Lambeth, 2. 63 Ibid .. 64 Ibid, 3 . . 65 Matthew Klam, "Status is ... for Navy Fighter Pilots; An Air-to-Air...Naval War College, 2004. Klain, Matthew . "Status is ... for Navy Fighter Pilots; An Air-to-Air Kill". NYTIMES. COM, November 15, 1998. http

  19. Professional solidarity versus responsibility for the health of the public: is a nurses' strike morally defensible?

    Science.gov (United States)

    Tabak, N; Wagner, N

    1997-07-01

    The purpose of this article is to deliberate the moral and legal dilemma entailed in the weapon of the labour strike as a pressure tactic on the Israeli Finance Ministry regarding job slots, budgets and, in effect, violating the collective agreement signed by the nurses and impairing patients' treatment, as opposed to refraining from striking and suffering the heavy burden of work, the lack of trained personnel, low wages, and the inability to give patients proper, high quality treatment.

  20. THE SINGLE MATCH APPROACH TO STRIKE RATE ADJUSTMENTS IN BATTING PERFORMANCE MEASURES IN CRICKET

    Directory of Open Access Journals (Sweden)

    Hermanus H. Lemmer

    2011-12-01

    Full Text Available Batting performance measures containing strike rate adjustments take into account the important fact that if two batsmen had scored the same number of runs in a match, the one with the better strike rate had performed best. But match conditions can influence the batting and bowling performances of cricket players. On a good pitch a batsman can get a good score at a high strike rate, but if the pitch was bad, a similar good score is normally accompanied by a much lower strike rate. The main objective of this study is to propose a method that can be used to make batsmen's scores comparable despite the fact that playing conditions might have been very different. The number of runs scored by a batsman is adjusted by comparing his strike rate with the overall strike rate of all the players in the specific match. These adjusted runs are then used in the most appropriate formula to calculate the average of the batsman. The method is illustrated by using the results of the Indian Premier League 2009 Twenty20 Series played during May and June 2009. The main conclusion is that the traditional average is not the most appropriate measure to compare batsmen's performances after conclusion of a short series.

  1. The Palos Verdes Fault offshore southern California: late Pleistocene to present tectonic geomorphology, seascape evolution and slip rate estimate based on AUV and ROV surveys

    Science.gov (United States)

    Brothers, Daniel S.; Conrad, James E.; Maier, Katherine L.; Paull, Charles K.; McGann, Mary L.; Caress, David W.

    2015-01-01

    The Palos Verdes Fault (PVF) is one of few active faults in Southern California that crosses the shoreline and can be studied using both terrestrial and subaqueous methodologies. To characterize the near-seafloor fault morphology, tectonic influences on continental slope sedimentary processes and late Pleistocene to present slip rate, a grid of high-resolution multibeam bathymetric data, and chirp subbottom profiles were acquired with an autonomous underwater vehicle (AUV) along the main trace of PVF in water depths between 250 and 600 m. Radiocarbon dates were obtained from vibracores collected using a remotely operated vehicle (ROV) and ship-based gravity cores. The PVF is expressed as a well-defined seafloor lineation marked by subtle along-strike bends. Right-stepping transtensional bends exert first-order control on sediment flow dynamics and the spatial distribution of Holocene depocenters; deformed strata within a small pull-apart basin record punctuated growth faulting associated with at least three Holocene surface ruptures. An upper (shallower) landslide scarp, a buried sedimentary mound, and a deeper scarp have been right-laterally offset across the PVF by 55 ± 5, 52 ± 4 , and 39 ± 8 m, respectively. The ages of the upper scarp and buried mound are approximately 31 ka; the age of the deeper scarp is bracketed to 17–24 ka. These three piercing points bracket the late Pleistocene to present slip rate to 1.3–2.8 mm/yr and provide a best estimate of 1.6–1.9 mm/yr. The deformation observed along the PVF is characteristic of strike-slip faulting and accounts for 20–30% of the total right-lateral slip budget accommodated offshore Southern California.

  2. Static deformation of two welded monoclinic elastic half-spaces due ...

    Indian Academy of Sciences (India)

    Static deformation of two monoclinic elastic half-spaces in welded contact due to a long inclined strike-slip fault situated in one of the half-spaces is studied analytically and numerically. Closedform algebraic expressions for the displacement at any point of the medium are obtained. The variation of the displacement at the ...

  3. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    The solution of static elastic deformation of a homogeneous, orthotropic elastic uniform half-space with rigid boundary due to a non-uniform slip along a vertical strike-slip fault of infinite length and finite width has been studied. The results obtained here are the generalisation of the results for an isotropic medium having rigid ...

  4. Static deformation of two welded monoclinic elastic half-spaces due ...

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    where τij is the stress tensor, uk is the displacement vector and Cijks are the elastic stiffnesses satisfying the symmetry relations. Cijks = Cjiks = Cksij. (2). Summation over repeated indices is understood. Keywords. Monoclinic elastic media; static deformation; strike-slip fault; welded half-spaces. Proc. Indian Acad. Sci.

  5. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    No evidence for shallow shear motion on the Mat Fault, a prominent strike slip fault in the Indo-Burmese wedge · R P Tiwari V K Gahalaut Ch U B Rao C Lalsawta B Kundu Malsawmtluanga · More Details Abstract Fulltext PDF. The motion between India and Sunda plates is accommodated along the Churachandpur Mao ...

  6. A Middle-Upper Miocene fluvial-lacustrine rift sequence in the Song Ba Rift, Vietnam

    DEFF Research Database (Denmark)

    Lars H., Nielsen; Henrik I., Petersen; Nguyen D., Dau

    2007-01-01

    The small Neogene Krong Pa graben is situated within the continental Song Ba Rift, which is bounded by strike-slip faults that were reactivated as extensional faults in Middle Miocene time. The 500 m thick graben-fill shows an overall depositional development reflecting the structural evolution, ...

  7. Static elastic deformation in an orthotropic half-space with rigid ...

    Indian Academy of Sciences (India)

    Yogita Godara

    2017-10-06

    Oct 6, 2017 ... In reality, the geometry of apparently vertical strike-slip faults is quite variable with depth. Elastic deformability combined with sam- ple asymmetry, i.e., the mechanical environment of all points on the surface are not identical and can cause non-uniform slip when there is a uni- form change in shear stress.

  8. Evaluating slab-plate coupling in the Indo-Australian plate

    NARCIS (Netherlands)

    Sandiford, Mike; Coblentz, David; Schellart, Wouter Pieter

    Distributed seismicity in the central Indian Ocean affords a unique opportunity to evaluate the extent of slab-plate coupling in the Indo-Australian plate. The mix of reverse-fault and strike-slip mechanisms in this region, with northwest-southeast to north-south maximum horizontal stress, SHmax,

  9. Fission-track evidence of tectonic evolution in the northwestern ...

    Indian Academy of Sciences (India)

    Guo-Qiang Sun

    2018-02-14

    Feb 14, 2018 ... The right panels are the age component and. Gaussian curve histograms. Cretaceous (102–85 Ma), the Kohistan Ladakh block in the northwestern Indian Plate collided with the Eurasian Plate (Jin 1999); subsequently, at 92–89 Ma, the deep part of the Altyn Tagh region commenced ductile strike-slip ...

  10. Fission-track evidence of tectonic evolution in the northwestern ...

    Indian Academy of Sciences (India)

    8

    right Y-axis, which indicates the age of that grain. The right panels are the age component and. Gaussian curve histograms. Figure 4. Evolution of the Altyn Tagh strike-slip fault (modified after Liu et al. 2001) a.At the end of the Mesozoic era, the Tibetan plateau started to uplift alone with the collision between the Indian and ...

  11. Magnetostratigraphy of the Xiaolongtan Formation bearing Lufengpithecus keiyuanensis in Yunnan, southwestern China : Constraint on the initiation time of the southern segment of the Xianshuihe–Xiaojiang fault

    NARCIS (Netherlands)

    Li, S.; Deng, Chenglong; Dong, Wei; Sun, Lu; Liu, S.; Qin, Huafeng; Yin, Jiyun; Ji, Xueping; Zhu, Rixiang

    2015-01-01

    The late Cenozoic extensional basins in Yunnan Province (southwestern China), which are kinematically linked with the regional strike-slip faults, can provide meaningful constraints on the fault activity history and tectonic evolution of the southeast margin of the Tibetan Plateau (SEMTP), and

  12. Pull-apart basin formation and development in narrow transform zones with application to the Dead Sea Basin

    NARCIS (Netherlands)

    Smit, J.H.W.; Brun, J.P.; Cloetingh, S.A.P.L.; Ben-Avraham, Z.

    2008-01-01

    Contrary to other examples, like Death Valley, California, and the Sea of Marmara, Turkey, the Dead Sea-type pull-apart basins form within a narrow transform corridor between strike-slip faults that are less than 10 km apart, much smaller than the crustal thickness of 35 km. In this paper we

  13. Tectonic Implication of the 5th March 2005, Doublet Earthquake in Ilan, Taiwan

    Directory of Open Access Journals (Sweden)

    En-Chao Yeh

    2016-01-01

    Full Text Available The 5th March 2005 earthquake doublet focal mechanism was determined as strike-slip faulting from Harvard and BATS moment tensor inversion. However, based on first motion polarities, the first shock has a normal focal mechanism (Wu et al. 2008a. This discrepancy has caused a debate over the focal mechanism solution because different focal mechanisms have different tectonic implications. Based on the dislocation determination from Global Position System (GPS measurements, we find this event includes both tensile and strike-slip components. This finding illustrates the reason for the differences in the determined focal mechanisms using two different types of seismic data and analyzing methods. Field mapping and microstructure examination results indicate that the ductile deformation around the study area was characterized by the evolution from transpression to transtension with a predominant strike-slip component, but present-day active structures may be dominated by normal faulting. Thus, the active tensile slip result determined from dislocation modeling strongly suggests that the back arc extension of the Okinawa trough influences the stress state in this region, and changes the major transtension from strike-slip faulting to normal faulting.

  14. Tectonic inversion in the Wandel Sea Basin

    DEFF Research Database (Denmark)

    Svennevig, Kristian; Guarnieri, Pierpaolo; Stemmerik, Lars

    2016-01-01

    Sheet and an upper Hondal Elv Thrust Sheet separated by a subhorizontal fault: the Central Detachment. The style of deformation and the structures described are interpreted as the result of Paleocene-Eocene N-S directed compression resulting in basin inversion with strike-slip faults only having minor...

  15. Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

    NARCIS (Netherlands)

    Maffione, Marco; Hernandez-Moreno, Catalina; Ghiglione, Matias C.; Speranza, Fabio; van Hinsbergen, Douwe J.J.; Lodolo, Emanuele

    2015-01-01

    The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known

  16. SUBJECT INDEX

    Indian Academy of Sciences (India)

    regions in the Indian Ocean. 261. Vertical propagation of baroclinic Kelvin waves along the west coast .... in a mesoscale model for the prediction of rainfall associated with mesoscale convective systems. 275. Drainage offsetting. Strike slip faulting inferred from offsetting of drain- ages: Lower Narmada basin, western India.

  17. Microstructural and seismic properties of the upper mantle underneath a rifted continental terrane (Baja California): An example of sub-crustal mechanical asthenosphere?

    NARCIS (Netherlands)

    Palasse, L.N.; Vissers, R.L.M.; Paulssen, H.; Basu, A.R.; Drury, M.R.

    2012-01-01

    The Gulf of California rift is a young and active plate boundary that links the San Andreas strike-slip fault system in California to the oceanic spreading system of the East Pacific Rise. The xenolith bearing lavas of the San Quintin volcanic area provide lower crust and upper mantle samples from

  18. Mantle strength of the San Andreas fault system and the role of mantle-crust feedbacks

    NARCIS (Netherlands)

    Chatzaras, V.; Tikoff, B.; Newman, J.; Withers, A.C.; Drury, M.R.

    2015-01-01

    In lithospheric-scale strike-slip fault zones, upper crustal strength is well constrained from borehole observations and fault rock deformation experiments, but mantle strength is less well known. Using peridotite xenoliths, we show that the upper mantle below the San Andreas fault system

  19. Dating brittle tectonic movements with cleft monazite

    DEFF Research Database (Denmark)

    Berger, Alfons; Gnos, E.; Janots, E.

    2013-01-01

    stress axis, which is characteristic for strike slip deformation. The inferred stress situation is consistent with observed kinematics and the opening of such clefts. Therefore, the investigated monazite-bearing cleft formed at the end of D2 and/or D3, and dextral movements along NNW dipping planes...

  20. Morphology and sedimentation in Caribbean montane streams" examples from Jamaica and Puerto Rico

    Science.gov (United States)

    R. Ahmad; F.N. Scatena; A Gupta

    1993-01-01

    This paper presents a summary description of the morphology, sedimentation, and behaviour of the montane streams of eastern Jamaica and eastern Puerto Rico. The area is located within a 200 km wide seismically active zone of Neogene left-lateral strike-slip deformation which defines the plate boundary between the Caribbean and North American Plates. Tropical storms,...

  1. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    However, disposition of the basins and their structural architecture indicate that the kinematics of all the basins cannot be extensional. To maintain kinematic compatibility with other basins as well as the bulk lateral extension, some basins ought to be of strike-slip origin. The disposition, shape and structural architecture of ...

  2. Strain analysis and stratigraphic status of Nongkhya, Sumer and ...

    Indian Academy of Sciences (India)

    effect of right and left lateral strike slip movement of Sumer conglomerate at Sumer and Adabasti points, respectively. This is a positive signature of ... northeastward counterclockwise movement of the. Indian plate producing severe ..... tinuation of the Prydze Bay Pan-African suture into. Northeastern India; Precamb. Res.

  3. Neotectonic aspects of the northern margin of the Adana–Cilicia ...

    Indian Academy of Sciences (India)

    Cilicia basins in the west and Iskenderun basin in the east) are located on the flanks of a partly submerged positive structure (a part of the Africa–Eurasia convergence zone) along which strike-slip faults are evident. This study summarizes the ...

  4. Static deformation of an orthotropic elastic layered medium due to a ...

    African Journals Online (AJOL)

    Closed-form analytic expressions for the deformation field at any point of a homogeneous, orthotropic, homogeneous elastic layer interfacing differently to a base due to non-uniform discontinuity (slip) along a very long strike-slip fault situated in the orthotropic elastic layer have been obtained. Four non-uniform slip profiles: ...

  5. Static deformation of two welded monoclinic elastic half-spaces due ...

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    Static deformation of two monoclinic elastic half-spaces in welded contact due to a long inclined strike-slip fault situated in one of the half-spaces is studied analytically and numerically. Closed- form algebraic expressions for the displacement at any point of the medium are obtained. The variation of the displacement at the ...

  6. Multistage magma emplacement and progressive strain accumulation in the shallow-level Krkonose-Jizera plutonic complex, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Žák, J.; Verner, K.; Sláma, Jiří; Kachlík, V.; Chlupáčová, M.

    2013-01-01

    Roč. 32, č. 5 (2013), s. 1493-1512 ISSN 0278-7407 Institutional support: RVO:67985831 Keywords : strike-slip tectonics * magnetic-susceptibility * Central-Europe * SW Poland * Krkonose granite * Variscan belt * Northeastern Brazil * fabric development * Sierra-Nevada * shrimp zircon Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.994, year: 2013

  7. Application of the region–time–length algorithm to study of ...

    Indian Academy of Sciences (India)

    P Puangjaktha

    2018-03-27

    Mar 27, 2018 ... the maximal strike-slip motion of faults in the. TLMB around 4±2 mm/yr conforming to the morphotectonic evidences mentioned by Lacassin. (1998), Fenton et al. (2003), and Iwakuni et al. (2004). Seismically, more than eight strong-to- major earthquakes (Mw ≥ 6) have occurred in this area during the three ...

  8. Two-dimensional deformation of a uniform half-space due to non ...

    Indian Academy of Sciences (India)

    ent from uniform one. The corresponding prob- lem of strike-slip and dip-slip faults in a uniform half-space has been discussed by several investiga- tors. Chinnery and Petrak (1968) used numerical. Keywords. Two-dimensional; vertical tensile fracture; static deformation; non-uniform movement. J. Earth Syst. Sci. 122, No.

  9. The 11 May 2011 earthquake at Lorca (SE Spain) viewed in a structural-tectonic context

    NARCIS (Netherlands)

    Vissers, R.L.M.; Meijninger, B.M.L.

    2011-01-01

    The Lorca earthquake of 11 May 2011 in the Betic Cordillera of SE Spain occurred almost exactly on the Alhama de Murcia fault, a marked fault that forms part of a NE-SW trending belt of faults and thrusts. The fault belt is reminiscent of a strike-slip corridor, but recent structural studies have

  10. Evidences of inclined transpression at the contact between ...

    Indian Academy of Sciences (India)

    zone may show different structures or dominance of certain type of structures, depending on whether that part is dominated by strike-slip, dip slip or compression. The present study finds evidences of inclined transpression at the contact between. Udayagiri and Vinjamuru group of NSB, which is the main focus of this paper.

  11. Concussion in professional football: biomechanics of the striking player--part 8.

    Science.gov (United States)

    Viano, David C; Pellman, Elliot J

    2005-02-01

    Concussive impacts in professional football were simulated in laboratory tests to determine the collision mechanics resulting in injury to the struck player and the biomechanics of the striking players, who were not concussed or neck-injured in the tackle. Twenty-seven helmet-to-helmet collisions were reconstructed in laboratory tests using Hybrid III dummies. The head impact velocity, direction, and kinematics matched game video. Translational and rotational head accelerations and six-axis upper neck loads and moments were used to evaluate how the striking player delivered the concussive blow. The neck injury criterion, Nij, was calculated to assess neck injury risks in the striking player. The time-averaged impact force reached 6372 +/- 2486 N at 7.2 milliseconds because of 46.8 +/- 21.7 g head acceleration and 3624 +/- 1729 N neck compression force in the striking player. Fifty-seven percent of the load was contributed by neck compression. The striking players had their heads down and lined up the impact axis through their necks and torsos. This allowed momentum transfer with minimal neck bending and increased the effective mass of the striking player to 1.67 times that of the struck player at peak load. The impact caused 94.3 +/- 27.5 g head acceleration in the concussed players and 67.9 +/- 14.5 g without concussion (t = 2.06, df = 25, P = 0.025). The striking player's Nij was greater than tolerance in 9 of 27 cases by exceeding the 4000 N neck compression limit. For these cases, the average neck compression force was 6631 +/- 977 N (range, 5210-8194 N). Nij was 1.25 +/- 0.16 for eight cases above the tolerance Nij = 1.0. In the NFL, striking players line up their heads, necks, and torsos to deliver maximum force to the other player in helmet-to-helmet impacts. The concussive force is from acceleration of the striking player's head and torso load through the neck. Even though neck responses exceeded tolerances, no striking player experienced neck injury or

  12. Initiation, evolution and extinction of pull-apart basins: Implications for opening of the Gulf of California

    Science.gov (United States)

    van Wijk, J.; Axen, G.; Abera, R.

    2017-11-01

    We present a model for the origin, crustal architecture, and evolution of pull-apart basins. The model is based on results of three-dimensional upper crustal elastic models of deformation, field observations, and fault theory, and is generally applicable to basin-scale features, but predicts some intra-basin structural features. Geometric differences between pull-apart basins are inherited from the initial geometry of the strike-slip fault step-over, which results from the forming phase of the strike-slip fault system. As strike-slip motion accumulates, pull-apart basins are stationary with respect to underlying basement, and the fault tips propagate beyond the rift basin, increasing the distance between the fault tips and pull-apart basin center. Because uplift is concentrated near the fault tips, the sediment source areas may rejuvenate and migrate over time. Rift flank uplift results from compression along the flank of the basin. With increasing strike-slip movement the basins deepen and lengthen. Field studies predict that pull-apart basins become extinct when an active basin-crossing fault forms; this is the most likely fate of pull-apart basins, because basin-bounding strike-slip systems tend to straighten and connect as they evolve. The models show that larger length-to-width ratios with overlapping faults are least likely to form basin-crossing faults, and pull-apart basins with this geometry are thus most likely to progress to continental rupture. In the Gulf of California, larger length-to-width ratios are found in the southern Gulf, which is the region where continental breakup occurred rapidly. The initial geometry in the northern Gulf of California and Salton Trough at 6 Ma may have been one of widely-spaced master strike-slip faults (lower length-to-width ratios), which our models suggest inhibits continental breakup and favors straightening of the strike-slip system by formation of basin-crossing faults within the step-over, as began 1.2 Ma when the

  13. Foot Strike Patterns Differ Between Children and Adolescents Growing up Barefoot vs. Shod.

    Science.gov (United States)

    Hollander, Karsten; de Villiers, Johanna Elsabe; Venter, Ranel; Sehner, Susanne; Wegscheider, Karl; Braumann, Klaus-Michael; Zech, Astrid

    2018-02-01

    Effects of early and permanent footwear use are not well understood. The aim of this study was to investigate the effects of habituation to footwear on foot strike patterns of children and adolescents. Healthy habitually barefoot and shod participants (aged 6-18 years) from South Africa (n=288) and Germany (n=390) performed multiple 20-m jogging and running trials with and without shoes. Each foot strike was captured using a high-speed camera to determine a rearfoot or non-rearfoot strike. The probability of a rearfoot strike in both cohorts and each age was analyzed by using a mixed-effects logistic regression adjusted for possible confounders. Habitually barefoot children showed a higher probability of using rearfoot strikes than habitually shod children (p<0.001). The probability was age-dependent and decreased in habitually barefoot children with age (OR barefoot-jogging =0.82, 95% CI, 0.71 to 0.96, p=0.014; OR barefoot-running =0.58, 95% CI, 0.50 to 0.67, p<0.001 and OR shod-running =0.68, 95% CI, 0.59 to 0.79, p<0.001). In habitually shod children, the probability increased significantly for shod jogging (OR=1.19, 95% CI, 1.05 to 1.35, p=0.006). To conclude, foot strike patterns of children are influenced by habituation to footwear. Younger habitually barefoot children show higher rates of rearfoot strikes for shod and barefoot running, and it converges in later adolescence. © Georg Thieme Verlag KG Stuttgart · New York.

  14. Motion in the north Iceland volcanic rift zone accommodated by bookshelf faulting

    Science.gov (United States)

    Green, Robert G.; White, Robert S.; Greenfield, Tim

    2014-01-01

    Along mid-ocean ridges the extending crust is segmented on length scales of 10-1,000km. Where rift segments are offset from one another, motion between segments is accommodated by transform faults that are oriented orthogonally to the main rift axis. Where segments overlap, non-transform offsets with a variety of geometries accommodate shear motions. Here we use micro-seismic data to analyse the geometries of faults at two overlapping rift segments exposed on land in north Iceland. Between the rift segments, we identify a series of faults that are aligned sub-parallel to the orientation of the main rift. These faults slip through left-lateral strike-slip motion. Yet, movement between the overlapping rift segments is through right-lateral motion. Together, these motions induce a clockwise rotation of the faults and intervening crustal blocks in a motion that is consistent with a bookshelf-faulting mechanism, named after its resemblance to a tilting row of books on a shelf. The faults probably reactivated existing crustal weaknesses, such as dyke intrusions, that were originally oriented parallel to the main rift and have since rotated about 15° clockwise. Reactivation of pre-existing, rift-parallel weaknesses contrasts with typical mid-ocean ridge transform faults and is an important illustration of a non-transform offset accommodating shear motion between overlapping rift segments.

  15. Assessment of Tsunami-related Geohazard Assessment for Coasts of Hersek Peninsula and Gulf of İzmit

    Directory of Open Access Journals (Sweden)

    Cem Gazioğlu

    2017-05-01

    Full Text Available Tsunamis are one of the most dreadful natural disasters; they could cause abysmal damage to all kind of lives in the hinterland within instantly. It is a major right-lateral moving fault that runs along the tectonic boundary between the Eurasian Plate to the north and the Anatolian Plate to the south. The western segment of the North Anatolian Fault splits into three main branches. The northern one of NAF is generally subdivided in several subsegments that have been the source of frequent large historical earthquakes. The Sea of Marmara coasts is located on the western extension of the NAFZ which is one of the most important active faults with strike-slip characteristics, which are not likely to generate tsunami. However, in the light of tsunami catalogs based on historical documents, it is possible to say that Sea of Marmara has tsunamigenic potential. The İstanbul shorelines, Gemlik Bay, Kapıdağ N-NE shores, Gelibolu, Hersek Peinsula and Gulf of İzmit are one of the most significant geohazards in Sea of Marmara due to the tsunami effect.

  16. Coseismic deformation and slip model of the 17 November 2015 M=6.5 earthquake, Lefkada Island, Greece

    Science.gov (United States)

    Ganas, Athanassios; Melgar, Diego; Briole, Pierre; Geng, Jianghui; Papathanassiou, George; Bozionelos, George; Avallone, Antonio; Valkaniotis, Sotirios; Mendonidis, Evangelos; Argyrakis, Panagiotis; Moshou, Alexandra; Elias, Panagiotis

    2016-04-01

    On November 17, 2015 a strong, shallow earthquake, Mw 6.5, occurred on the island of Lefkada along a strike-slip fault with right-lateral sense of slip. The event triggered widespread environmental effects that were mainly reported at the south and western part of the island while moving towards the eastern part, the intensity and severity of these earthquake-induced deformations were decreased. Coseismic deformation was measured in the order of tens of centimeters of horizontal motion by continuous GPS stations of NOANET (the NOA GPS network) and by InSAR (Sentinel 1A image pairs). Released interferograms from various groups show a large decorrelation area that extends almost along all the western coast of Lefkada, observation which provides strong support of landsliding. We also found extensive landslides during field work and no surface ruptures. A coseismic slip model was produced from the ascending InSAR, which it's cleaner than the GPS only and both data sets have ~90% variance reduction. The fault dips to the east-southeast at an angle of 65-70 degrees.

  17. Eastern Denali Fault surface trace map, eastern Alaska and Yukon, Canada

    Science.gov (United States)

    Bender, Adrian M.; Haeussler, Peter J.

    2017-05-04

    We map the 385-kilometer (km) long surface trace of the right-lateral, strike-slip Denali Fault between the Totschunda-Denali Fault intersection in Alaska, United States and the village of Haines Junction, Yukon, Canada. In Alaska, digital elevation models based on light detection and ranging and interferometric synthetic aperture radar data enabled our fault mapping at scales of 1:2,000 and 1:10,000, respectively. Lacking such resources in Yukon, we developed new structure-from-motion digital photogrammetry products from legacy aerial photos to map the fault surface trace at a scale of 1:10,000 east of the international border. The section of the fault that we map, referred to as the Eastern Denali Fault, did not rupture during the 2002 Denali Fault earthquake (moment magnitude 7.9). Seismologic, geodetic, and geomorphic evidence, along with a paleoseismic record of past ground-rupturing earthquakes, demonstrate Holocene and contemporary activity on the fault, however. This map of the Eastern Denali Fault surface trace complements other data sets by providing an openly accessible digital interpretation of the location, length, and continuity of the fault’s surface trace based on the accompanying digital topography dataset. Additionally, the digitized fault trace may provide geometric constraints useful for modeling earthquake scenarios and related seismic hazard.

  18. Late Oligocene to present contractional structure in and around the Susitna basin, Alaska—Geophysical evidence and geological implications

    Science.gov (United States)

    Saltus, Richard W.; Stanley, Richard G.; Haeussler, Peter J.; Jones, James V.; Potter, Christopher J.; Lewis, Kristen A.

    2016-01-01

    The Cenozoic Susitna basin lies within an enigmatic lowland surrounded by the Central Alaska Range, Western Alaska Range (including the Tordrillo Mountains), and Talkeetna Mountains in south-central Alaska. Some previous interpretations show normal faults as the defining structures of the basin (e.g., Kirschner, 1994). However, analysis of new and existing geophysical data shows predominantly (Late Oligocene to present) thrust and reverse fault geometries in the region, as previously proposed by Hackett (1978). A key example is the Beluga Mountain fault where a 50-mGal gravity gradient, caused by the density transition from the igneous bedrock of Beluga Mountain to the >4-km-thick Cenozoic sedimentary section of Susitna basin, spans a horizontal distance of ∼40 km and straddles the topographic front. The location and shape of the gravity gradient preclude a normal fault geometry; instead, it is best explained by a southwest-dipping thrust fault, with its leading edge located several kilometers to the northeast of the mountain front, concealed beneath the shallow glacial and fluvial cover deposits. Similar contractional fault relationships are observed for other basin-bounding and regional faults as well. Contractional structures are consistent with a regional shortening strain field inferred from differential offsets on the Denali and Castle Mountain right-lateral strike-slip fault systems.

  19. Size distribution and roundness of clasts within pseudotachylytes of the Gangavalli Shear Zone, Salem, Tamil Nadu: An insight into its origin and tectonic significance

    Science.gov (United States)

    Behera, Bhuban Mohan; Thirukumaran, V.; Soni, Aishwaraya; Mishra, Prasanta Kumar; Biswal, Tapas Kumar

    2017-06-01

    Gangavalli (Brittle) Shear Zone (Fault) near Attur, Tamil Nadu exposes nearly 50 km long and 1-3 km wide NNE-SSW trending linear belt of cataclasites and pseudotachylyte produced on charnockites of the Southern Granulite Terrane. Pseudotachylytes, as well as the country rock, bear the evidence of conjugate strike slip shearing along NNE-SSW and NW-SE directions, suggesting an N-S compression. The Gangavalli Shear Zone represents the NNE-SSW fault of the conjugate system along which a right lateral shear has produced seismic slip motion giving rise to cataclasites and pseudotachylytes. Pseudotachylytes occur as veins of varying width extending from hairline fracture fills to tens of meters in length. They carry quartz as well as feldspar clasts with sizes of few mm in diameter; the clast sizes show a modified Power law distribution with finer ones (0.4) due to thermal decrepitation. In a large instance, devitrification has occurred producing albitic microlites that suggest the temperature of the pseudotachylyte melt was >1000^{circ }\\hbox {C}. Thus, pseudotachylyte veins act as a proxy to understand the genetic process involved in the evolution of the shear zone and its tectonic settings.

  20. Comparison of simultaneous variations of the ionospheric total electron content and geomagnetic field associated with strong earthquakes

    Directory of Open Access Journals (Sweden)

    Sh. Naaman

    2001-01-01

    Full Text Available In this paper, perturbations of the ionospheric Total Electron Content (TEC are compared with geomagnetic oscillations. Comparison is made for a few selected periods, some during earthquakes in California and Japan and others at quiet periods in Israel and California. Anomalies in TEC were extracted using Global Positioning System (GPS observations collected by GIL (GPS in Israel and the California permanent GPS networks. Geomagnetic data were collected in some regions where geomagnetic observatories and the GPS network overlaps. Sensitivity of the GPS method and basic wave characteristics of the ionospheric TEC perturbations are discussed. We study temporal variations of ionospheric TEC structures with highest reasonable spatial resolution around 50 km. Our results show no detectable TEC disturbances caused by right-lateral strike-slip earthquakes with minor vertical displacement. However, geomagnetic observations obtained at two observatories located in the epicenter zone of a strong dip-slip earthquake (Kyuchu, M = 6.2, 26 March 1997 revealed geomagnetic disturbances occurred 6–7 h before the earthquake.

  1. San-in shear zone in southwest Japan, revealed by GNSS observations

    Science.gov (United States)

    Nishimura, Takuya; Takada, Youichiro

    2017-06-01

    A right-lateral shear zone in the San-in region, southwest Japan, has been proposed by previous geological and seismological studies. It locates 350 km north of the Nankai Trough, that is, the main plate boundary between the subducting Philippine Sea and overriding Amurian plates and presumably accommodates a part of the relative plate motion. We present a geodetic evidence of the proposed shear zone using GNSS velocity data. Distinct shear deformation is identified only between 132.5°E and 135°E along a coastline which is a part of the proposed shear zone, and we propose to call the geodetically identified shear zone as the San-in shear zone (SSZ). The SSZ is a concentrated deformation zone with a width of 50 km and can be modeled by a deep creep on a vertical strike slip fault with a creep rate of 5 mm/year. There are some active faults parallel and oblique to the overall trend of the SSZ, but no single active fault coincides with the SSZ. Lineaments of microseismicity and source faults of large earthquakes are almost oriented in NNW-SSE in the SSZ and oblique to the overall trend of the SSZ. They are interpreted as conjugate Riedel shears. Based on these geodetic, seismological, and geomorphological observations, we suggest that the SSZ is a developing and young shear zone in a geological time scale.[Figure not available: see fulltext.

  2. Palaeomagnetic results from an archaeological site near Rome (Italy: new insights for tectonic rotation during the last 0.5 Myr

    Directory of Open Access Journals (Sweden)

    M. Pirro

    2004-06-01

    Full Text Available Approximately 20 km north-east of Rome, along the modern trace of the Tiburtina road, recent archaeological diggings have brought to light a system of aqueduct galleries constructed by Roman engineers. This site falls inside the Acque Albule Basin, a travertine plateau Upper Pleistocene in age, that has been interpreted as a rhombshaped pull-apart basin created by strike-slip faulting within a N-S shear zone. This study provides evidence that two narrow water channels of this aqueduct system were significantly deformed by tectonic movement that occurred subsequent to their construction (II-III century A.D.. The geometry of the deformation pattern is compatible with that expected for a shear zone bounded by N-S oriented, right-lateral faults. The palaeomagnetic study of the volcanic formation («Pozzolane Rosse» Formation, 457± 4 kyr containing the Roman aqueduct system evidences significant clockwise rotation around sub-vertical axis, consistent with the above-mentioned tectonic style.

  3. 2001 Bhuj-Kachchh earthquake: surface faulting and its relation with neotectonics and regional structures, Gujarat, Western India

    Directory of Open Access Journals (Sweden)

    M. G. Thakkar

    2003-06-01

    Full Text Available Primary and secondary surface deformation related to the 2001 Bhuj-Kachchh earthquake suggests that thrusting movement took place along an E-W fault near the western extension of the South Wagad Fault, a synthetic fault of the Kachchh Mainland Fault (KMF. Despite early reconnaissance reports that concluded there was no primary surface faulting, we describe an 830 m long, 15-35 cm high, east-west-trending thrust fault scarp near where the seismogenic fault plane would project to the surface, near Bharodiya village (between 23°34.912'N, 70°23.942'E and 23°34.304'N, 70°24.884'E. Along most of the scarp Jurassic bedrock is thrust over Quaternary deposits, but the fault scarp also displaces Holocene alluvium and an earth dam, with dips of 13° to 36° south. Secondary co-seismic features, mainly liquefaction and lateral spreading, dominate the area south of the thrust. Transverse right-lateral movement along the «Manfara Fault» and a parallel fault near Bharodiya suggests segmentation of the E-W master faults. Primary (thrust surface rupture had a length of 0.8 km, maximum displacement of about 35 cm, and average displacement of about 15 cm. Secondary (strike-slip faulting was more extensive, with a total end-to-end length of 15 km, maximum displacement of 35 cm, and average displacement of about 20 cm.

  4. An Mw = 7.7 slow earthquake in 1960 near the Aysén Fjord region, Chile

    Science.gov (United States)

    Kanamori, Hiroo; Rivera, Luis

    2017-10-01

    We re-examine the source characteristics of an Ms = 6.9 earthquake in Chile which occurred on 1960 June 6, near the Aysén Fjord region where a remarkable earthquake swarm occurred in 2007 with more than 7000 earthquakes and hundreds of landslides. The June 6 event occurred during the aftershock activity of the 1960 May 22, Mw = 9.5 great Chilean earthquake. A recently found well-calibrated strain seismogram of the June 6 event recorded at Isabella (ISA), California, is the impetus to this study. We confirm that this event is a slow earthquake caused by a source process extending at least 190 s with a seismic moment of M0 = 4.5 × 1020 Nṡm (Mw = 7.7). Although the mechanism cannot be uniquely determined, an NS trending right-lateral strike-slip mechanism is consistent with the ISA record. The depth cannot be constrained well, but the slowness of the event suggests that it may have occurred in a somewhat deeper high-temperature ductile environment caused by nearby subduction of the Chile Rise. The mechanism and the proximity of this event to the Liquiñe-Ofqui fault (LOF) which extends north-south over 1000 km along the Chilean coast suggest that the June 6 event represents a slip on this fault. The large moment of the June 6 event indicates strong interaction between the Nazca-South American plate boundary and the LOF with significant slip partitioning.

  5. Megathrust and accretionary wedge properties and behaviour in the Makran subduction zone

    Science.gov (United States)

    Penney, Camilla; Tavakoli, Farokh; Saadat, Abdolreza; Nankali, Hamid Reza; Sedighi, Morteza; Khorrami, Fateme; Sobouti, Farhad; Rafi, Zahid; Copley, Alex; Jackson, James; Priestley, Keith

    2017-06-01

    We study the Makran subduction zone, along the southern coasts of Iran and Pakistan, to gain insights into the kinematics and dynamics of accretionary prism deformation. By combining techniques from seismology, geodesy and geomorphology, we are able to put constraints on the shape of the subduction interface and the style of strain across the prism. We also address the long-standing tectonic problem of how the right-lateral shear taken up by strike-slip faulting in the Sistan Suture Zone in eastern Iran is accommodated at the zone's southern end. We find that the subduction interface in the western Makran may be locked, accumulating elastic strain, and move in megathrust earthquakes. Such earthquakes, and associated tsunamis, present a significant hazard to populations around the Arabian Sea. The time-dependent strain within the accretionary prism, resulting from the megathrust earthquake cycle, may play an important role in the deformation of the Makran region. By considering the kinematics of the 2013 Balochistan and Minab earthquakes, we infer that the local gravitational and far-field compressive forces in the Makran accretionary prism are in balance. This force balance allows us to calculate the mean shear stress and effective coefficient of friction on the Makran megathrust, which we find to be 5-35 MPa and 0.01-0.03, respectively. These values are similar to those found in other subduction zones, showing that the abnormally high sediment thickness in the offshore Makran does not significantly reduce the shear stress on the megathrust.

  6. A 3000-year record of surface-rupturing earthquakes at Günalan: variable fault-rupture lengths along the 1939 Erzincan earthquake-rupture segment of the North Anatolian Fault, Turkey

    Directory of Open Access Journals (Sweden)

    Jeffrey George Fraser

    2013-01-01

    Full Text Available The North Anatolian Fault is a ca. 1200-km-long, right-lateral, strike-slip fault that forms the northern boundary of the Anatolian plate. A damaging sequence of earthquakes ruptured almost the entire fault in the twentieth century. This study adds to the growing number of paleoseismic investigations of the 350-km-long 1939 Erzincan earthquake-rupture segment, which is towards the eastern end of the North Anatolian Fault in Turkey. Using three paleoseismic trenches located along ca. 2 km of the principal fault strand, this study determines the timing of five earthquakes prior to the 1939 earthquake. The first three of these earthquakes are correlated to historical earthquakes in A.D. 1668, 1254 and 499, and two further events were identified as occurring from 881-673 B.C. and from 1406-1291 B.C. (2v age ranges. By comparing the earthquake timing determined in this study to results from other paleoseismic investigations of the 1939 rupture segment, it becomes clear that this historical rupture segment does not always rupture in unison. This analysis indicates that the A.D. 499 earthquake was the last time the 1939 rupture segment ruptured in unison; partial ruptures of the 1939 rupture segment occur more frequently, and can also produce large magnitude earthquakes (MW >7.

  7. The 2012 Mw 8.6 Wharton Basin sequence: A cascade of great earthquakes generated by near-orthogonal, young, oceanic mantle faults

    Science.gov (United States)

    Hill, Emma M.; Yue, Han; Barbot, Sylvain; Lay, Thorne; Tapponnier, Paul; Hermawan, Iwan; Hubbard, Judith; Banerjee, Paramesh; Feng, Lujia; Natawidjaja, Danny; Sieh, Kerry

    2015-05-01

    We improve constraints on the slip distribution and geometry of faults involved in the complex, multisegment, Mw 8.6 April 2012 Wharton Basin earthquake sequence by joint inversion of high-rate GPS data from the Sumatran GPS Array (SuGAr), teleseismic observations, source time functions from broadband surface waves, and far-field static GPS displacements. This sequence occurred under the Indian Ocean, ˜400 km offshore Sumatra. The events are extraordinary for their unprecedented rupture of multiple cross faults, deep slip, large strike-slip magnitude, and potential role in the formation of a discrete plate boundary between the Indian and Australian plates. The SuGAr recorded static displacements of up to ˜22 cm, along with time-varying arrivals from the complex faulting, which indicate that the majority of moment release was on young, WNW trending, right-lateral faults, counter to initial expectations that an old, lithospheric, NNE trending fracture zone played the primary role. The new faults are optimally oriented to accommodate the present-day stress field. Not only was the greatest moment released on the younger faults, but it was these that sustained very deep slip and high stress drop (>20 MPa). The rupture may have extended to depths of up to 60 km, suggesting that the oceanic lithosphere in the northern Wharton Basin may be cold and strong enough to sustain brittle failure at such depths. Alternatively, the rupture may have occurred with an alternative weakening mechanism, such as thermal runaway.

  8. Rapid intraplate strain accumulation in the New Madrid seismic zone

    Science.gov (United States)

    Liu, Lanbo; Zoback, Mark D.; Segall, Paul

    1992-09-01

    Remeasurement of a triangulation network in the southern part of the New Madrid seismic zone with the Global Positioning System has revealed rapid crustal strain accumulation since the 1950s. This area experienced three large (moment magnitudes greater than 8) earthquakes in 1811 to 1812. The orientation and sense of shear is consistent with right-lateral strike slip motion along a northeast-trending fault zone (as indicated by current seismicity). Detection of crustal strain accumulation may be a useful discriminant for identifying areas where potentially damaging intraplate earthquakes may occur despite the absence of large earthquakes during historic time. ubject Type="Secondary">Nature Conservation 36 36 6 6 6 2005 12 Springer Science+Business Media, Inc. 2005 373 10.1007/s00267-004-0373-6 6 Effects of Short- and Long-Term Disturbance Resulting from Military Maneuvers on Vegetation and Soils in a Mixed Prairie Area Research 849 861 2004 1 1 2005 10 7 Springer Science+Business Media, Inc. 2005

  9. Induced surface deformation and seismicity during 2011-2012 at the Húsmúli reinjection site, Iceland

    Science.gov (United States)

    Juncu, Daniel; Árnadóttir, Thóra; Geirsson, Halldór; Guðmundsson, Gunnar; Gunnarsson, Gunnar; Hooper, Andy; Hreinsdóttir, Sigrún; Michalczewska, Karolina

    2017-04-01

    While induced seismicity related to fluid injection is a common occurrence, deformation due to injection is rarely observed. At the Hellisheidi power plant in SW Iceland we detect both induced seismicity and deformation during the initial phase of geothermal wastewater reinjection. The largest seismic events in the sequence were two earthquakes of M3.8 and M4.0 on 15 October 2011, after reinjection was started in September 2011 with a flow rate of around 550 l/s. After the intense induced seismicity started, a few GNSS sites in the area were operated semi-continuously, as there was no continuous station nearby. The GNSS data reveal a transient signal which indicates that most of the deformation occured in the first months after the injection started. Surface deformation is also evident in SAR interferograms in the time interval of June 2011 to May 2012. We use an inverse modeling approach and simulate the geodetic data (InSAR and GNSS) to find the most plausible source for the deformation signal. We test whether the deformation was caused by co-seismic motion on N-S right-lateral strike slip faults due to the largest events in October 2011. We also examine other source models that may explain the deformation. Finally, we estimate Coulomb stress changes in the area to test what processes could have activated slip on pre-existing faults to examine the causal relationship between the deformation and the induced seismicity.

  10. Southern Appalachian Regional Seismic Network

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, S.C.C.; Johnston, A.C.; Chiu, J.M. [Memphis State Univ., TN (United States). Center for Earthquake Research and Information

    1994-08-01

    The seismic activity in the southern Appalachian area was monitored by the Southern Appalachian Regional Seismic Network (SARSN) since late 1979 by the Center for Earthquake Research and Information (CERI) at Memphis State University. This network provides good spatial coverage for earthquake locations especially in east Tennessee. The level of activity concentrates more heavily in the Valley and Ridge province of eastern Tennessee, as opposed to the Blue Ridge or Inner Piedmont. The large majority of these events lie between New York - Alabama lineament and the Clingman/Ocoee lineament, magnetic anomalies produced by deep-seated basement structures. Therefore SARSN, even with its wide station spacing, has been able to define the essential first-order seismological characteristics of the Southern Appalachian seismic zone. The focal depths of the southeastern U.S. earthquakes concentrate between 8 and 16 km, occurring principally beneath the Appalachian overthrust. In cross-sectional views, the average seismicity is shallower to the east beneath the Blue Ridge and Piedmont provinces and deeper to the west beneath the Valley and Ridge and the North American craton. Results of recent focal mechanism studies by using the CERI digital earthquake catalog between October, 1986 and December, 1991, indicate that the basement of the Valley and Ridge province is under a horizontal, NE-SW compressive stress. Right-lateral strike-slip faulting on nearly north-south fault planes is preferred because it agrees with the trend of the regional magnetic anomaly pattern.

  11. Southern Appalachian Regional Seismic Network

    International Nuclear Information System (INIS)

    Chiu, S.C.C.; Johnston, A.C.; Chiu, J.M.

    1994-08-01

    The seismic activity in the southern Appalachian area was monitored by the Southern Appalachian Regional Seismic Network (SARSN) since late 1979 by the Center for Earthquake Research and Information (CERI) at Memphis State University. This network provides good spatial coverage for earthquake locations especially in east Tennessee. The level of activity concentrates more heavily in the Valley and Ridge province of eastern Tennessee, as opposed to the Blue Ridge or Inner Piedmont. The large majority of these events lie between New York - Alabama lineament and the Clingman/Ocoee lineament, magnetic anomalies produced by deep-seated basement structures. Therefore SARSN, even with its wide station spacing, has been able to define the essential first-order seismological characteristics of the Southern Appalachian seismic zone. The focal depths of the southeastern U.S. earthquakes concentrate between 8 and 16 km, occurring principally beneath the Appalachian overthrust. In cross-sectional views, the average seismicity is shallower to the east beneath the Blue Ridge and Piedmont provinces and deeper to the west beneath the Valley and Ridge and the North American craton. Results of recent focal mechanism studies by using the CERI digital earthquake catalog between October, 1986 and December, 1991, indicate that the basement of the Valley and Ridge province is under a horizontal, NE-SW compressive stress. Right-lateral strike-slip faulting on nearly north-south fault planes is preferred because it agrees with the trend of the regional magnetic anomaly pattern

  12. Foot strike patterns of recreational and sub-elite runners in a long-distance road race.

    Science.gov (United States)

    Larson, Peter; Higgins, Erin; Kaminski, Justin; Decker, Tamara; Preble, Janine; Lyons, Daniela; McIntyre, Kevin; Normile, Adam

    2011-12-01

    Although the biomechanical properties of the various types of running foot strike (rearfoot, midfoot, and forefoot) have been studied extensively in the laboratory, only a few studies have attempted to quantify the frequency of running foot strike variants among runners in competitive road races. We classified the left and right foot strike patterns of 936 distance runners, most of whom would be considered of recreational or sub-elite ability, at the 10 km point of a half-marathon/marathon road race. We classified 88.9% of runners at the 10 km point as rearfoot strikers, 3.4% as midfoot strikers, 1.8% as forefoot strikers, and 5.9% of runners exhibited discrete foot strike asymmetry. Rearfoot striking was more common among our sample of mostly recreational distance runners than has been previously reported for samples of faster runners. We also compared foot strike patterns of 286 individual marathon runners between the 10 km and 32 km race locations and observed increased frequency of rearfoot striking at 32 km. A large percentage of runners switched from midfoot and forefoot foot strikes at 10 km to rearfoot strikes at 32 km. The frequency of discrete foot strike asymmetry declined from the 10 km to the 32 km location. Among marathon runners, we found no significant relationship between foot strike patterns and race times.

  13. Select injury-related variables are affected by stride length and foot strike style during running.

    Science.gov (United States)

    Boyer, Elizabeth R; Derrick, Timothy R

    2015-09-01

    Some frontal plane and transverse plane variables have been associated with running injury, but it is not known if they differ with foot strike style or as stride length is shortened. To identify if step width, iliotibial band strain and strain rate, positive and negative free moment, pelvic drop, hip adduction, knee internal rotation, and rearfoot eversion differ between habitual rearfoot and habitual mid-/forefoot strikers when running with both a rearfoot strike (RFS) and a mid-/forefoot strike (FFS) at 3 stride lengths. Controlled laboratory study. A total of 42 healthy runners (21 habitual rearfoot, 21 habitual mid-/forefoot) ran overground at 3.35 m/s with both a RFS and a FFS at their preferred stride lengths and 5% and 10% shorter. Variables did not differ between habitual groups. Step width was 1.5 cm narrower for FFS, widening to 0.8 cm as stride length shortened. Iliotibial band strain and strain rate did not differ between foot strikes but decreased as stride length shortened (0.3% and 1.8%/s, respectively). Pelvic drop was reduced 0.7° for FFS compared with RFS, and both pelvic drop and hip adduction decreased as stride length shortened (0.8° and 1.5°, respectively). Peak knee internal rotation was not affected by foot strike or stride length. Peak rearfoot eversion was not different between foot strikes but decreased 0.6° as stride length shortened. Peak positive free moment (normalized to body weight [BW] and height [h]) was not affected by foot strike or stride length. Peak negative free moment was -0.0038 BW·m/h greater for FFS and decreased -0.0004 BW·m/h as stride length shortened. The small decreases in most variables as stride length shortened were likely associated with the concomitant wider step width. RFS had slightly greater pelvic drop, while FFS had slightly narrower step width and greater negative free moment. Shortening one's stride length may decrease or at least not increase propensity for running injuries based on the variables

  14. Extremely Shallow Extensional Faulting Near Geothermal Fields

    Science.gov (United States)

    Hudnut, K. W.; Wei, S.; Donnellan, A.; Fielding, E. J.; Graves, R. W.; Helmberger, D. V.; Liu, Z.; Parker, J. W.; Treiman, J. A.

    2013-12-01

    Surface faulting has been discovered in association with a shallow extensional M 4.9 earthquake, the source properties of which have also been studied by modeling of broadband seismic data and geodetic imagery. This M 4.9 and also a M 4.6 shallow normal event occurred late in the Brawley Swarm of August 2012, a dominantly strike-slip sequence with events up to M 5.5 (Hauksson et al., SRL 2013 and Wei et al., GRL 2013). The point source waveform inversions reveal normal mechanisms and centroid depths of ~2.5 km for both events, while the modeling of the geodetic data indicates a compatible depth of ~2.0 km. The M 4.9 event had unusually large (~40 cm) and sudden (~1.0 - 1.5 km/sec) slip, considering its extremely shallow depth. The earlier and larger strike-slip events during the Aug. 2012 swarm were on a left-lateral SW-NE oriented vertical planar cross-fault, whereas the M 4.6 and M 4.9 occurred on a SSW-NNE oriented, west-dipping plane. Airborne imagery obtained using Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) revealed a surface fault rupture that was subsequently confirmed and documented in the field in May 2013. A pre-existing but previously un-mapped fault sustained west-down surface slip of up to 18 × 2 cm along breaks extending ~3.5 km along a NNE orientation, and ruptured beneath and under a railroad track and pipeline (without breaking them). UAVSAR and seismological data were used jointly to image the source properties of the M 4.9 earthquake in detail. Typically, the uppermost few kms of right-lateral faults in the Salton Trough exhibit creep, especially after larger earthquakes, as in 1979 and 1987. On this basis, general models of stable sliding within the uppermost few kms have been developed. In this case, however, the joint inversion indicates that seismic energy was radiated by slip of up to 40 cm on a fault plane extending from the surface to a depth of only ~3 km, extending ~4 km along-strike, and dipping ~45° west, with west

  15. Acute neuromuscular responses to short and long roundhouse kick striking paces in professional Muay Thai fighters.

    Science.gov (United States)

    Cimadoro, Giuseppe; Mahaffey, Ryan; Babault, Nicolas

    2018-04-04

    Muay Thai fighters strongly rely on the use of the roundhouse kick due to its effectiveness (i.e. power) and implications on the final score. Therefore, different striking tempos at full power are used during training as a method to enhance kicking power. However, the neuromuscular responses are unknown. Thus, the goal of this study was to investigate neuromuscular responses to a single bout of shorter (every second = H1) and longer (every 3s = H3) kick striking time intervals, measured with the countermovement jump (CMJ). Nine professional Muay Thai fighters participated in this randomized, cross-over trial. CMJs were measured on force plates before and after (post 0min, post 5min, post 10min, post 20min and post 30min) two striking (1set x 20reps) conditions (H1; H3). Although no difference was observed between H1 and H3 values, neuromuscular fatigue parameters displayed different patterns over time. CMJ height decreased immediately after H3 striking (PMuay Thai and conditioning coaches should focus on hard striking with both long and slow pacing during specific heavy bag or pad work.

  16. The balancing act between the constitutional right to strike and the constitutional right to education

    Directory of Open Access Journals (Sweden)

    H J (Jaco Deacon

    2014-06-01

    Full Text Available While the South African Constitution enshrines both children's right to a basic education and teachers' right to strike, conflict between these two often occurs when the way in which teachers' unions conduct strike actions detracts from learners' education. This article identifies the parties affected by industrial action in the school context, and then proceeds to examine educators' right to strike as defined by the provisions of the Labour Relations Act. The unique implications of picketing in the education environment are then discussed, covering relevant questions such as where pickets may be held, the issue of picketing rules as well as unprotected pickets. Even though we are faced with a qualified right to strike as opposed to an unqualified right to education, the South African reality seems to be that striking teachers are handled with kid gloves. It is therefore concluded that the vast range of existing laws regulating protest action should be applied more effectively. One of the most important aspects should be the picketing rules, which should clearly determine whether picketing in fact contributes to resolution of the dispute, and how learners' interests and rights may best be actualised.

  17. Lightning Strike Ablation Damage Characteristic Analysis for Carbon Fiber/Epoxy Composite Laminate with Fastener

    Science.gov (United States)

    Yin, J. J.; Li, S. L.; Yao, X. L.; Chang, F.; Li, L. K.; Zhang, X. H.

    2016-08-01

    In order to analyze the lightning strike ablation damage characteristic of composite laminate with fastener, based on the energy-balance relationship in lightning strike, mathematical analysis model of ablation damage of composite laminate with fastener was constructed. According to the model, an effective three dimensional thermal-electrical coupling analysis finite element model of composite laminate with fastener suffered from lightning current was established based on ABAQUS, and lightning strike ablation damage characteristic was analyzed. Analytical results reveal that lightning current could conduct through the thickness direction of the laminate due to the existence of metallic fastener, and then distribute to all layers, finally conducted in-the-plane of each layer, conductive ability of different layup orientations depend on potential distribution and in-the-plane electrical conductivity along potential gradient declining direction; different potential boundaries correspond to different potential distribution in each layer, and result in conductive ability of different layup orientations was changed, then caused different lightning strike ablation damage distribution. According to the investigation in this paper, we can recognize the lightning strike ablation damage characteristic of composite laminate with fastener qualitatively.

  18. Public Servants' right to strike in Lesotho, Botswana and South Africa – A Comparative Study

    Directory of Open Access Journals (Sweden)

    Tamara Cohen

    2014-11-01

    Full Text Available Restrictions on the rights of public officers to strike are permitted by the Constitutions of Lesotho, Botswana and South Africa, where such limitations are reasonable, necessary and justifiable in a democratic society. The limitation of this right in the context of public servants is endorsed by the ILO in the Freedom of Association Digest of Decisions and Principles which holds that "[t]he right to strike can be restricted or even prohibited in the public service or in essential services in so far as a strike there could cause serious hardship to the national community and provided that these limitations are accompanied by certain compensatory guarantees". Public officers in Lesotho are deprived of the right to join trade unions or to strike, without exception or justification. Furthermore in Lesotho no dispute resolution mechanism exists to effectively facilitate the final resolution of disputes of interest in the public sector. This paper considers whether the limitations imposed on the freedom and right to strike of public officers in Lesotho are in breach of international obligations and are reasonable and justifiable in a free and democratic society committed to the rule of law. In so doing a comparative analysis of the jurisdictions of South Africa and Botswana is undertaken. It concludes that Lesotho is in breach of its obligations as a member state of the ILO and its constitutional commitment to freedom of association and needs to be urgently addressed.

  19. [Hunger striking in prisons: ethics and the ethical and legal aspects].

    Science.gov (United States)

    García-Guerrero, J

    2013-01-01

    Hunger strike is a common form of protest in prisons and is a potential cause of many types of problems, both for the prison administration and the doctors who care for prisoners who participate in one. Issues of conflict of rights and obligations involved, and how to treat people who are subject to the Administration, which in this case takes the position of guarantor, have created major controversies over doctrine. Conscientious objection and the conflict of dual loyalty of doctors working in prisons are also issues closely linked to a prison hunger strike. In this paper we review the solution given to the problem of treatment of a prison hunger strike from three perspectives: ethics, ethical and legal.

  20. Down the needle! Should public sector nurses in South Africa have the right to strike?

    Science.gov (United States)

    Heunis, C; Pelser, A J

    1997-09-01

    It is often argued that because the public sector provides essential services, it is intolerable that the citizenry be denied its entitlement because of a domestic dispute between civil servants (such as nurses) and the state. In this contribution an attempt is made to unravel a number of ideological, legislative and ethical issues relating to the right of the public sector nurse to strike. Notwithstanding the merits of opposite contentions, it is argued that public sector nurses should, in fact, have the right to strike. If this right is to be legitimized, however, due consideration should be given to problems relating to nurses' labour organisation and preventative measures to ensure minimal harm to patients in the planning and in the course of strike action.

  1. Evaluation of blade-strike models for estimating the biological performance of large Kaplan hydro turbines

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, T. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ploskey, G. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Richmond, M. C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2005-11-01

    Bio-indexing of hydro turbines has been identified as an important means to optimize passage conditions for fish by identifying operations for existing and new design turbines that minimize the probability of injury. Cost-effective implementation of bio-indexing requires the use of tools such as numerical and physical turbine models to generate hypotheses for turbine operations that can be tested at prototype scales using live fish. Blade strike has been proposed as an index variable for the biological performance of turbines. Report reviews an evaluation of the use of numerical blade-strike models as a means with which to predict the probability of blade strike and injury of juvenile salmon smolt passing through large Kaplan turbines on the mainstem Columbia River.

  2. ST-segment elevation following lightning strike: case report and review of the literature.

    Science.gov (United States)

    Akın, Alper; Bilici, Meki; Demir, Fikri; Gözü Pirinççioğlu, Ayfer; Yıldırım, Ahmet

    2015-01-01

    Lightning strikes may cause injury to the heart, ranging from slight electrocardiographic changes to fatal damage. As heart injury is the most important cause of mortality in these patients, cardiac monitoring is crucial. Even though various ECG changes have been reported, published data on pathologic ST-segment changes is scarce. Herein, we present a seven-year old patient with ST-segment elevation following a lightning strike. There is not sufficient data regarding lightning-related myocardial ischemia. However, because of the similar effects of lightning strikes and high-voltage electric shocks, we believe myocardial injury related to lightning may be managed in the same manner as is cardiac involvement associated with electric shock.

  3. [Lightning strikes and lightning injuries in prehospital emergency medicine. Relevance, results, and practical implications].

    Science.gov (United States)

    Hinkelbein, J; Spelten, O; Wetsch, W A

    2013-01-01

    Up to 32.2% of patients in a burn center suffer from electrical injuries. Of these patients, 2-4% present with lightning injuries. In Germany, approximately 50 people per year are injured by a lightning strike and 3-7 fatally. Typically, people involved in outdoor activities are endangered and affected. A lightning strike usually produces significantly higher energy doses as compared to those in common electrical injuries. Therefore, injury patterns vary significantly. Especially in high voltage injuries and lightning injuries, internal injuries are of special importance. Mortality ranges between 10 and 30% after a lightning strike. Emergency medical treatment is similar to common electrical injuries. Patients with lightning injuries should be transported to a regional or supraregional trauma center. In 15% of all cases multiple people may be injured. Therefore, it is of outstanding importance to create emergency plans and evacuation plans in good time for mass gatherings endangered by possible lightning.

  4. Practice Makes Perfect?: The Changing Civilian Toll of CIA Drone Strikes in Pakistan

    Directory of Open Access Journals (Sweden)

    Avery Plaw

    2011-12-01

    Full Text Available U.S. officials have recently claimed that the CIA has sharply reduced the number of civilian casualties resulting from covert Predator and Reaper drone strikes in the Taliban-controlled agencies of Northwest Pakistan. Critics, especially in Pakistan, along with human rights NGOs have, however, questioned these claims. This article examines independent databases tracking the drone strikes and finds that there is significant support for the U.S. officials’ claims, or at least for their more moderate assertions. It also briefly reviews the explanations that have been offered for the declining civilian death toll from drone strikes. It shows that there is reason to believe that this development is the deliberate result of adjustments to CIA targeting procedures and improvements in spy networks and technology, and thus is likely to prove broadly sustainable at least for the immediate future.

  5. Probability, consequences, and mitigation for lightning strikes to Hanford site high-level waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    Zach, J.J.

    1996-08-01

    The purpose of this report is to summarize selected lightning issues concerning the Hanford Waste Tanks. These issues include the probability of lightning discharge striking the area immediately adjacent to a tank including a riser, the consequences of significant energy deposition from a lightning strike in a tank, and mitigating actions that have been or are being taken. The major conclusion of this report is that the probability of a lightning strike depositing sufficient energy in a tank to cause an effect on employees or the public is unlikely;but there are insufficient, quantitative data on the tanks and waste to prove that. Protection, such as grounding of risers and air terminals on existing light poles, is recommended.

  6. Ankle and knee kinetics between strike patterns at common training speeds in competitive male runners.

    Science.gov (United States)

    Kuhman, Daniel; Melcher, Daniel; Paquette, Max R

    2016-01-01

    The purpose of this study was to investigate the interaction of foot strike and common speeds on sagittal plane ankle and knee joint kinetics in competitive rear foot strike (RFS) runners when running with a RFS pattern and an imposed forefoot strike (FFS) pattern. Sixteen competitive habitual male RFS runners ran at two different speeds (i.e. 8 and 6 min mile(-1)) using their habitual RFS and an imposed FFS pattern. A repeated measures analysis of variance was used to assess a potential interaction between strike pattern and speed for selected ground reaction force (GRF) variables and, sagittal plane ankle and knee kinematic and kinetic variables. No foot strike and speed interaction was observed for any of the kinetic variables. Habitual RFS yielded a greater loading rate of the vertical GRF, peak ankle dorsiflexor moment, peak knee extensor moment, peak knee eccentric extensor power, peak dorsiflexion and sagittal plane knee range of motion compared to imposed FFS. Imposed FFS yielded greater maximum vertical GRF, peak ankle plantarflexor moment, peak ankle eccentric plantarflexor power and sagittal plane ankle ROM compared to habitual RFS. Consistent with previous literature, imposed FFS in habitual RFS reduces eccentric knee extensor and ankle dorsiflexor involvement but produce greater eccentric ankle plantarflexor action compared to RFS. These acute differences between strike patterns were independent of running speeds equivalent to typical easy and hard training runs in competitive male runners. Current findings along with previous literature suggest differences in lower extremity kinetics between habitual RFS and imposed FFS running are consistent among a variety of runner populations.

  7. The Crustal Structure and Seismicity of Eastern Venezuela

    Science.gov (United States)

    Schmitz, M.; Martins, A.; Sobiesiak, M.; Alvarado, L.; Vasquez, R.

    2001-12-01

    Eastern Venezuela is characterized by a moderate to high seismicity, evidenced recently by the 1997 Cariaco earthquake located on the El Pilar Fault, a right lateral strike slip fault which marks the plate boundary between the Caribbean and South-American plates in this region. Recently, the seismic activity seems to migrate towards the zone of subduction of the Lesser Antilles in the northeast, where a mb 6.0 earthquake occurred in October 2000 at 120 km of depth. Periodical changes in the seismic activity are related to the interaction of the stress fields of the strike-slip and the subduction regimes. The seismic activity decreases rapidly towards to the south with some disperse events on the northern edge of the Guayana Shield, related to the Guri fault system. The crustal models used in the region are derived from the information generated by the national seismological network since 1982 and by microseismicity studies in northeastern Venezuela, coinciding in a crustal thickness of about 35 km in depth. Results of seismic refraction measurements for the region were obtained during field campains in 1998 (ECOGUAY) for the Guayana Shield and the Cariaco sedimentary basin and in 2001 (ECCO) for the Oriental Basin. The total crustal thickness decreases from about 45 km on the northern edge of the Guayana Shield to some 36 km close to El Tigre in the center of the Oriental Basin. The average crustal velocity decreases in the same sense from 6.5 to 5.8 km/s. In the Cariaco sedimentary basin a young sedimentary cover of 1 km thickness with a seismic velocity of 2 km/s was derived. Towards the northern limit of the South-American plate, no deep seismic refraction data are available up to now. The improvement of the crustal models used in that region would constitute a step forward in the analysis of the seismic hazard. Seismic refraction studies funded by CONICIT S1-97002996 and S1-2000000685 projects and PDVSA (additional drilling and blasting), recording equipment

  8. BOLIVAR: Crustal Structure Across the Caribbean-South American Plate Boundary at 70W: Results from Refraction and Reflection Data.

    Science.gov (United States)

    Guedez, M. C.; Zelt, C. A.; Magnani, M. B.; Levander, A.; Christeson, G. L.; Sawyer, D. S.

    2005-12-01

    The active-seismic component of the BOLIVAR project (Broadband Ocean and Land Investigations of Venezuela and the Antilles arc Region) was completed in June 2004. Among the goals of BOLIVAR is to study the structure of the South America-Caribbean plate boundary as a site of likely continental growth by island arc accretion of the Leeward Antilles arc to the South American continent. In the west end of the Venezuelan basin the complex motion across the plate boundary is poorly understood. Other studies have concluded that the Caribbean Plate is subducting beneath the South American Plate and the Leeward Antilles arc is being accreted to older continental crust. Complicating this picture, the Maracaibo block is being displaced northward along the Bocono and Santa Marta strike-slip faults, while the Oca fault is a paleo-strand of the large right-lateral strike-slip system of the plate boundary. We present results of analyses of refraction and reflection seismic data along a 450 km long onshore-offshore profile at 70oW, extending from 10oN to 14.3oN. The refraction data include 40 Ocean Bottom Seismometer (OBS) and 348 Reftek Texan land seismometers that recorded the R/V Ewing airgun shots. The land stations also recorded two large landshots to provide reversed refraction coverage onshore. A 2-D velocity model obtained from travel time inversion of first arrivals shows that the Caribbean crust is anomalously thick, typical of oceanic plateau, ~ 15-20 km. Low velocity sediments, on the Caribbean oceanic plateau, are observed subducting beneath the South-Caribbean deformed belt over a distance of 75-100 km. We also observe low velocities associated with the Paraguana/Falcon basin extending from onshore to offshore depths of 3 km. We observe localized high compressional velocities spatially associated with the Oca fault. Similar high velocity bodies are observed on other BOLIVAR transects (see Avé Lallemant et al., this session). A migrated stack of the marine reflection

  9. Deformation of Aztec Sandstone at Valley of Fire of Nevada: failure modes, sequence of deformation, structural products and their interplay with paleo fluids

    Science.gov (United States)

    Aydin, A.

    2014-12-01

    The Valley of Fire State Park, 60 km NE of Las Vegas, is a beacon of knowledge for deformation of Aztec Sandstone, a cross-bedded quartz arenite deposited in the Aztec-Navajo-Nugget erg in early Jurassic. It displays great diversity of physical properties, different localization types and micromechanics. The two deformation episodes, the Sevier folding & thrusting and the Basin & Range extension affected the area. The appearance of compaction bands marks the earliest deformation structure and their distribution, orientation, and dimension are controlled by the depositional architecture and loading. The earliest shear structures in the area are the Muddy Mountain, Summit, and Willow Tank thrusts and numerous small-scale bed-parallel faults. They altogether produced several kilometers of E-SE transport and shortening in the late Cretaceous and display numerous shear bands in its damage zone within the Aztec Sandstone. Shear bands also occur along dune boundaries and cross-bed interfaces. These observations indicate that the early deformation of the sandstone was accommodated by strain localization with various kinematics. The younger generation of faults in the area is of mid-Miocene age, and crops out pervasively. It includes a series of small offset normal faults (less than a few ten meters) which can be identified at steep cliff faces. These faults are highly segmented and are surrounded by a dense population of splay fractures. A large number of these splays were later sheared sequentially resulting in a well-defined network of left- and right-lateral strike-slip faults with slip magnitudes up to a few kilometers in the Park. The formation mechanisms of both the normal and strike-slip faults can be characterized as the sliding along planes of initial weaknesses and the accompanying cataclastic deformation. Some of the initial weak planes are associated with the depositional elements such as interdune boundaries and cross-bed interfaces while others are joint

  10. Integration of Space-borne SAR and Ground-Based Radar for 3D Deformation Mapping of the Central Calaveras Fault at Coyote Dam

    Science.gov (United States)

    Werner, C. L.; Baker, B.; Milillo, P.; Magnard, C.; Strozzi, T.; Wegmüller, U.

    2017-12-01

    The Central Calaveras Fault (CCF) passes directly through Coyote Dam located southeast of Morgan Hill, California. This earthen embankment dam owned and operated by the Santa Clara Valley Water District (District), has experienced over 80 cm of accumulated fault creep since its construction in 1936. The average slip rate is 10 to 15 mm/year as measured using surveying, GPS, and more recently, terrestrial radar interferometry (TRI). The CCF is a right-lateral strike-slip fault that has the potential for a M7.25 earthquake resulting in meter scale displacement. In 2015, the District initiated a geological analysis of the CCF integrating past surveying, GPS data, TRI deformation mapping, paleoseismic trenching, and boreholes. The initial TRI survey included dam measurements from two locations, imaging the upstream and downstream embankments over the period from February to July 2015. The TRI data from the downstream embankment data showed a complex deformation pattern not consistent with a strike-slip fault model. A second measurement campaign was initiated utilizing multiple radar viewpoints with the aim of resolving the 3D deformation field of the downstream embankment. The campaign occurred between May and November 2016 and showed an unexpected strong westward and downward movement exceeding 2 cm/year (see Figure). TRI data were acquired from 4 separate observation points every 2 to 4 weeks during this campaign. Point target analysis methods were used to avoid contamination of the deformation data by vegetation and radar shadow. Deformation uncertainty in the downstream fault zone was relatively high due to the nearly coplanar arrangement of the TRI observation points. To better constrain the vertical deformation, in this report we integrate spaceborne measurements from the Cosmo-SkyMed (CS) radar satellite in the 3D deformation solution. The LOS to the satellite has a large vertical component not present in the TRI measurement geometry that facilitates the

  11. Structural control on fluid flow at the Dominga IOCG deposit in Northern Chile: insights from microtextural analysis

    Science.gov (United States)

    Heuser, G.; Arancibia, G.; Veloso, E. A.; Reich, M.; Morales, H.

    2017-12-01

    The Fe-Cu paragenetic assemblages at the Cretaceous Dominga IOCG deposit in northern Chile (2082 Mt at 23% Fe, 0.07% Cu) show a spatial and genetic affinity with major structural systems in the district: the Early Structural System (ESS), El Tofo Structural System (ETSS) and Intermediate Structural System (ISS), developed under different tectonic regimes, from transtension (ESS) to transpression (ETSS, ISS). The ESS is a NE-ENE-trending right-lateral strike slip duplex related to the formation of biotite-magnetite mineralization in Fe-rich bands parallel to bedding (stage I), and magnetite-apatite-actinolite-quartz hydrothermal breccia (stage II). The ETSS is a NNE left-lateral fault breccia related to K-feldspar veins and anhydrite-chalcopyrite hydrothermal breccia (stage III). The ISS is a NW-WNW left lateral strike slip duplex composed of calcite veins (stage IV). However, an understanding of fault-driven fluid flow mechanisms and their impact on the studied Fe-Cu deposit is still lacking. We analyzed representative textures from veins and hydrothermal breccias of stages II, III and IV. Microstructural analysis was made in thin/polished sections normal and parallel to the vein wall using optical and scanning electron microscopy techniques. Stage II shows euhedral magnetite with ilmenite lamellae exsolution textures and intergrowths between magnetite and anhedral mosaic quartz. Hydrothermal breccias contain euhedral quartz with double-terminated crystal shapes and concentric growth zoning surrounded by plumose quartz. Stage III exhibits zoned K-feldspar veins, banded plumose quartz veins, and mosaic subhedral anhydrite. Stage IV is characterized by banded veins of plumose and rhombic calcite, and dilational jogs with rhombic calcite. The observed microtextures suggest slow cooling of high temperature Fe-Cu-rich fluid, suspension in aqueous fluid during crystal growth, and boiling. Despite the different tectonic regimes, the paleo-fluids at the Dominga IOCG

  12. Refining fault slip rates using multiple displaced terrace risers-An example from the Honey Lake fault, NE California, USA

    Science.gov (United States)

    Gold, Ryan D.; Briggs, Richard W.; Crone, Anthony J.; DuRoss, Christopher B.

    2017-11-01

    Faulted terrace risers are semi-planar features commonly used to constrain Quaternary slip rates along strike-slip faults. These landforms are difficult to date directly and therefore their ages are commonly bracketed by age estimates of the adjacent upper and lower terrace surfaces. However, substantial differences in the ages of the upper and lower terrace surfaces (a factor of 2.4 difference observed globally) produce large uncertainties in the slip-rate estimate. In this investigation, we explore how the full range of displacements and bounding ages from multiple faulted terrace risers can be combined to yield a more accurate fault slip rate. We use 0.25-m cell size digital terrain models derived from airborne lidar data to analyze three sites where terrace risers are offset right-laterally by the Honey Lake fault in NE California, USA. We use ages for locally extensive subhorizontal surfaces to bracket the time of riser formation: an upper surface is the bed of abandoned Lake Lahontan having an age of 15.8 ± 0.6 ka and a lower surface is a fluvial terrace abandoned at 4.7 ± 0.1 ka. We estimate lateral offsets of the risers ranging between 6.6 and 28.3 m (median values), a greater than fourfold difference in values. The amount of offset corresponds to the riser's position relative to modern stream meanders: the smallest offset is in a meander cutbank position, whereas the larger offsets are in straight channel or meander point-bar positions. Taken in isolation, the individual terrace-riser offsets yield slip rates ranging from 0.3 to 7.1 mm/a. However, when the offset values are collectively assessed in a probabilistic framework, we find that a uniform (linear) slip rate of 1.6 mm/a (1.4-1.9 mm/a at 95% confidence) can satisfy the data, within their respective uncertainties. This investigation demonstrates that integrating observations of multiple offset elements (crest, midpoint, and base) from numerous faulted and dated terrace risers at closely spaced

  13. Main shock and aftershocks of the December 13, 1990, Eastern Sicily earthquake

    Directory of Open Access Journals (Sweden)

    M. Di Bona

    1995-06-01

    Full Text Available n this paper we describe the location and the fault plane solution of the December 13, 1990, Eastern Sicily earthquake (ML = 5.4, and of its aftershock sequence. Because the main shock location is not well constrained due to the geometry of the permanent National Seismic Network in this area, we used a "master event" algorithm to locate it in relation to a well located aftershock. The revised location is slightly offshore Eastern Sicily, 4.8 km north of the largest aftershock (ML = 4.6 that occurred on December 16, 1990. The main shock has a strike-slip mechanism, indicating SE-NW compression with either left lateral motion on a NS plane, or right lateral on an EW plane. Two days after the main event we deployed a local network of eight digital stations, that provided accurate locations of the aftershocks, and the estimate of source parameters for the strongest earthquake. We observed an unusual quiescence after the ML = 5.4 event, that lasted until December 16, when a ML = 4.6 earthquake occurred. The fault plane solution of this aftershock shows normal faulting on E-W trending planes. Between December 16 and January 6, 1991, a sequence of at least 300 aftershock" was recorded by the local network. The well located earthquakes define a small source region of approximately 5 x 2 x 5 km3, with hypocentral depths ranging between 15 and 20 km. The paucity of large aftershocks, the time gap between the main shock occurrence and the beginning of the aftershock sequence (3.5 days, their different focal mechanisms (strike-slip vs. normal, and the different stress drop between main shock and after- shock suggest that the ML = 5.4 earthquake is an isolated event. The sequence of aftershocks began with the ML = 4.6 event, which is probably linked to the main shock with a complex mechanism of stress redistribution after the main faulting episode.

  14. Stress state reconstruction of oblique collision and evolution of deformation partitioning in W-Zagros (Iran, Kermanshah)

    Science.gov (United States)

    Navabpour, Payman; Angelier, Jacques; Barrier, Eric

    2008-11-01

    The W-Zagros of Iran is characterized by a deformation partitioning pattern with a right-lateral strike-slip motion along the Main Recent Fault and a shortening component across the Zagros Simple Fold Belt under the late Cenozoic N-S oblique collision between the Arabian and Iranian continental plates. In this study, we examined the brittle structures that developed during the mountain building process in the High Zagros Belt of Kermanshah Province, which is structurally located between the two partitioned components of deformation, to decipher the history of polyphase deformation and variations in stress fields within the sedimentary cover since the onset of collision. The earthquake focal mechanisms of W-Zagros were analysed to evaluate the recent stress fields within the basement. Analytic inversion techniques enabled us to determine and separate different brittle tectonic regimes in terms of stress tensors. Brittle tectonic analyses were carried out to reconstruct possible geometrical relationships between different structures and to establish relative chronologies of the corresponding stress tensor, with reference to folding. Our stress reconstruction indicates a major change in stress state from a Miocene-Pliocene syn-folding compressional regime to a Pliocene-Recent post-folding strike-slip system, with a significant anticlockwise reorientation of the horizontal σ1 stress axis from NE-SW to N-S. The results of the recent stress states indicate that the stress trends are similar throughout the basement and sedimentary cover. The differences between stress and strain axes suggest different possible degrees in partitioning of seismic and aseismic deformation, as revealed by earthquake focal mechanisms in the basement and geodetic surveys at the surface of the sedimentary cover. The integrated palaeostress results on the regional tectonic framework suggest that the late Cenozoic brittle tectonic evolution of the W-Zagros was achieved through the transition from

  15. It's Our Fault: better defining earthquake risk in Wellington, New Zealand

    Science.gov (United States)

    Van Dissen, R.; Brackley, H. L.; Francois-Holden, C.

    2012-12-01

    The Wellington region, home of New Zealand's capital city, is cut by a number of major right-lateral strike slip faults, and is underlain by the currently locked west-dipping subduction interface between the down going Pacific Plate, and the over-riding Australian Plate. In its short historic period (ca. 160 years), the region has been impacted by large earthquakes on the strike-slip faults, but has yet to bear the brunt of a subduction interface rupture directly beneath the capital city. It's Our Fault is a comprehensive study of Wellington's earthquake risk. Its objective is to position the capital city of New Zealand to become more resilient through an encompassing study of the likelihood of large earthquakes, and the effects and impacts of these earthquakes on humans and the built environment. It's Our Fault is jointly funded by New Zealand's Earthquake Commission, Accident Compensation Corporation, Wellington City Council, Wellington Region Emergency Management Group, Greater Wellington Regional Council, and Natural Hazards Research Platform. The programme has been running for six years, and key results to date include better definition and constraints on: 1) location, size, timing, and likelihood of large earthquakes on the active faults closest to Wellington; 2) earthquake size and ground shaking characterization of a representative suite of subduction interface rupture scenarios under Wellington; 3) stress interactions between these faults; 4) geological, geotechnical, and geophysical parameterisation of the near-surface sediments and basin geometry in Wellington City and the Hutt Valley; and 5) characterisation of earthquake ground shaking behaviour in these two urban areas in terms of subsoil classes specified in the NZ Structural Design Standard. The above investigations are already supporting measures aimed at risk reduction, and collectively they will facilitate identification of additional actions that will have the greatest benefit towards further

  16. Refining fault slip rates using multiple displaced terrace risers—An example from the Honey Lake fault, NE California, USA

    Science.gov (United States)

    Gold, Ryan D.; Briggs, Richard; Crone, Anthony J.; Duross, Christopher

    2017-01-01

    Faulted terrace risers are semi-planar features commonly used to constrain Quaternary slip rates along strike-slip faults. These landforms are difficult to date directly and therefore their ages are commonly bracketed by age estimates of the adjacent upper and lower terrace surfaces. However, substantial differences in the ages of the upper and lower terrace surfaces (a factor of 2.4 difference observed globally) produce large uncertainties in the slip-rate estimate. In this investigation, we explore how the full range of displacements and bounding ages from multiple faulted terrace risers can be combined to yield a more accurate fault slip rate. We use 0.25-m cell size digital terrain models derived from airborne lidar data to analyze three sites where terrace risers are offset right-laterally by the Honey Lake fault in NE California, USA. We use ages for locally extensive subhorizontal surfaces to bracket the time of riser formation: an upper surface is the bed of abandoned Lake Lahontan having an age of 15.8 ± 0.6 ka and a lower surface is a fluvial terrace abandoned at 4.7 ± 0.1 ka. We estimate lateral offsets of the risers ranging between 6.6 and 28.3 m (median values), a greater than fourfold difference in values. The amount of offset corresponds to the riser's position relative to modern stream meanders: the smallest offset is in a meander cutbank position, whereas the larger offsets are in straight channel or meander point-bar positions. Taken in isolation, the individual terrace-riser offsets yield slip rates ranging from 0.3 to 7.1 mm/a. However, when the offset values are collectively assessed in a probabilistic framework, we find that a uniform (linear) slip rate of 1.6 mm/a (1.4–1.9 mm/a at 95% confidence) can satisfy the data, within their respective uncertainties. This investigation demonstrates that integrating observations of multiple offset elements (crest, midpoint, and base) from numerous faulted and dated terrace risers at closely spaced

  17. Vådområder, flyvepladser og risiko for bird strikes

    DEFF Research Database (Denmark)

    Christensen, Thomas Kjær; Hounisen, Jens Peder

    2015-01-01

    Rapporten udgør en opdatering af Teknisk anvisning nr. 23 fra DMU (Christensen & Hounisen 2006), omhandlende risikovurdering for bird strikes (kollisioner mellem fugle og fly) i danske lufthavne ved etablering af vådområder nær disse. Rapporten analyserer relationen mellem ændrede forekomster af...... søer og enge/moser indenfor lufthavnenes sikkerhedszoner på 13 km og forekomsten af bird strikes i perioden 2006-2013. Anbefalinger til placering og størrelse af vådområder i lufthavnenes sikkerhedszoner er opdateret på baggrund af rapportens resultater....

  18. FD-TD numerical simulation of an entire lightning strike on the C160 aircraft

    Science.gov (United States)

    Alliot, J. C.; Grando, J.; Muller, J. D.; Ferrieres, X.

    1991-01-01

    Experimental transient electromagnetic field measurements were performed on a Transall C160 aircraft during in-flight lightning strikes. The data allow a test of the predictive capabilities of a three dimensional time domain finite difference code (ALICE) developed at ONERA in order to investigate lightning-aircraft interactions. Using a transfer function technique in the 3D code, it is shown that a bi-leader attached to an aircraft can be simulated by a linear model, and so the electromagnetic fields can be calculated anywhere on the vehicle. Comparison of experimental and numerical results were made for several lightning strikes. Skin current density and electromagnetic field distributions are discussed in detail.

  19. Direct and nearby lightning strike interaction with test power distribution lines

    Science.gov (United States)

    Schoene, Jens Daniel

    The interaction of direct and nearby rocket-triggered lightning with two unenergized three-phase power distribution lines of about 800 m length was studied at the International Center for Lightning Research and Testing in Florida. A horizontally-configured line was tested in 1999 and 2000, a vertically-configured line in 2001, 2002, and 2003, and a vertically-configured line with overhead ground wire in 2004. All lines were equipped with arresters and, additionally, in 2003, the vertical line had a polemounted transformer. During the 2000, 2001, and 2002 direct strike experiments, arresters frequently failed, but there was no arrester failures either during the 2003 direct strike experiment when the transformer was on the line or during the 2004 direct strike experiment when the lightning current was injected into the overhead ground wire. All line configurations except the one tested in 2004 commonly exhibited flashovers. The division of return stroke currents for the vertically-configured line was initially similar to the division on the horizontally-configured line (that is, the arresters closest to the strike point conducted the bulk of the impulsive current). After some tens of microseconds the currents in all arresters on the vertically-configured line equalized, while the close arrester currents on the horizontally-configured line still conducted significantly more current than the remote arresters. The lightning current division for direct strikes to a phase conductor is successfully modeled with the Electromagnetic Transient Program (EMTP) for the vertically-configured line and, if the residual voltage of the close arresters is reduced by 20%, successfully modeled for the horizontally-configured line. Currents on the vertically-configured line induced by nearby lightning strikes were measured and compared to results calculated using the LIOV-EMTP96 code. It was found that during a lightning strike 11 m from a grounded line pole, a significant fraction of

  20. Research on Line Patrol Strategy of 110kV Transmission Line after Lightning Strike

    Directory of Open Access Journals (Sweden)

    Li Mingjun

    2016-01-01

    Full Text Available Lightning faults occupy in the majority of instantaneous fault and reclosing can usually be successful, so power supply can be restored without immediate patrol in many cases. Firstly, this paper introduces the lightning fault positioning and identifying method. Then test electrical performance of insulators after lightning strike from 110kV lines. Data shows that lightning strike has little effect on the electric performance of insulator. Finally, illustrating disposal process of the 110 kV transmission line after lightning fault, certifying that the power supply reliability be ensured without line patrol.