WorldWideScience

Sample records for rapidly subsiding east-west

  1. Rapid groundwater-related land subsidence in Yemen observed by multi-temporal InSAR

    Science.gov (United States)

    Abdullin, Ayrat; Xu, Wenbin; Kosmicki, Maximillian; Jonsson, Sigurjon

    2015-04-01

    Several basins in Yemen are suffering from a rapid drawdown of groundwater, which is the most important water source for agricultural irrigation, industry and domestic use. However, detailed geodetic measurements in the region have been lacking and the extent and magnitude of groundwater-related land subsidence has been poorly known. We used 13 ascending ALOS and 15 descending Envisat images to study land subsidence of several basins in Yemen, with a special focus on the Sana'a and Mabar basins. From multitemporal synthetic aperture radar interferometric analysis (persistent scatterers (PS) and small baseline subsets (SBAS)) we examined the spatio-temporal behavior of the subsidence induced by depletion of groundwater aquifer systems from November 2003 to February 2011. In the interferometric data processing, we carefully chose interferogram pairs to minimize spatial and temporal decorrelation, because of high subsidence rates and the type of land cover. Our results show that the spatial pattern of subsidence remained quite stable during the observation period in both the Sana'a and Mabar basins. In the Sana'a basin, the maximum subsidence rate exceeded 14 cm/year in the radar line-of-sight (LOS) direction between 2003 and 2008 in an agricultural area just north of Sana'a city, where water wells have been drying up according to the well data. The subsidence rate was lower in the urban areas, or approximately 1 cm/year, exhibiting annual variations. The main subsidence was found in the center and southern parts of the city, while deformation in the northern part is less obvious. For the Mabar basin, the subsidence rate exceeded 30 cm/year in the agricultural area north of the town of Mabar during 2007 - 2011. The southern part of the Mabar basin also experienced high subsidence rates, although somewhat lower than to the north. Excessive water pumping is the main cause of the ground subsidence and it has already led to extensive ground fracturing at the edge of some

  2. Rapid groundwater-related land subsidence in Yemen observed by multi-temporal InSAR

    KAUST Repository

    Abdullin, Ayrat

    2015-04-01

    Several basins in Yemen are suffering from a rapid drawdown of groundwater, which is the most important water source for agricultural irrigation, industry and domestic use. However, detailed geodetic measurements in the region have been lacking and the extent and magnitude of groundwater-related land subsidence has been poorly known. We used 13 ascending ALOS and 15 descending Envisat images to study land subsidence of several basins in Yemen, with a special focus on the Sana\\'a and Mabar basins. From multitemporal synthetic aperture radar interferometric analysis (persistent scatterers (PS) and small baseline subsets (SBAS)) we examined the spatio-temporal behavior of the subsidence induced by depletion of groundwater aquifer systems from November 2003 to February 2011. In the interferometric data processing, we carefully chose interferogram pairs to minimize spatial and temporal decorrelation, because of high subsidence rates and the type of land cover. Our results show that the spatial pattern of subsidence remained quite stable during the observation period in both the Sana\\'a and Mabar basins. In the Sana\\'a basin, the maximum subsidence rate exceeded 14 cm/year in the radar line-of-sight (LOS) direction between 2003 and 2008 in an agricultural area just north of Sana\\'a city, where water wells have been drying up according to the well data. The subsidence rate was lower in the urban areas, or approximately 1 cm/year, exhibiting annual variations. The main subsidence was found in the center and southern parts of the city, while deformation in the northern part is less obvious. For the Mabar basin, the subsidence rate exceeded 30 cm/year in the agricultural area north of the town of Mabar during 2007 - 2011. The southern part of the Mabar basin also experienced high subsidence rates, although somewhat lower than to the north. Excessive water pumping is the main cause of the ground subsidence and it has already led to extensive ground fracturing at the edge

  3. Investigating Rapid Uplift and Subsidence Near Norris, Yellowstone, During 2013-2014

    Science.gov (United States)

    Stovall, W. K.; Cervelli, P. F.; Shelly, D. R.

    2014-12-01

    Although Yellowstone's last magmatic eruption occurred about 70,000 years ago, hydrothermal explosions, earthquakes, and ground deformation still occur as testament to ongoing volcanic and tectonic processes. Since the late 1990s, a network of continuously recording Global Positioning System (GPS) receivers has recorded uplift and subsidence of the caldera and northwest caldera margin near Norris Geyser Basin. Previous deformation episodes have shown opposing vertical motion at the two sites, which has been attributed to temporal variations in magmatic fluid flux from the caldera laterally through the Norris-Mammoth fault corridor that intersects the caldera's northwest margin (Dzurisin et al., 2012; Wicks et al., 2006). These episodes have exhibited gradual changes, transitioning from uplift to subsidence (and vice versa) over weeks to months. Large earthquake swarms accompanied transitions from caldera uplift to subsidence in 1985 and 2010. Recent deformation in Yellowstone differs from previously observed episodes. In the latter half of 2013, uplift began around Norris, and by January of 2014 it reached rates of over 15 cm/yr. Also at the start of 2014, caldera deformation shifted from approximately 4 years of slow subsidence to slow uplift. On March 30, 2014, a M4.8 earthquake, the largest in Yellowstone since 1980, occurred northwest of Norris Geyser Basin near the center of uplift. Shortly after the event, deformation near Norris abruptly reversed to rapid subsidence (over 20 cm/yr). Caldera uplift began to accelerate around the same time. Thus, uplift can occur simultaneously in both the caldera and the Norris area, and dramatic reversals from rapid uplift to rapid subsidence can occur within a matter of days. While the complexity of the deformation defies a simple explanation, we hypothesize that the rapid transition from uplift to subsidence at Norris may indicate that the M4.8 earthquake opened a pathway for fluid migration away from Norris and allowed an

  4. Rapid post-rift tectonic subsidence events in the Pearl River Mouth Basin, northern South China Sea margin

    Science.gov (United States)

    He, Min; Zhong, Guangfa; Liu, Xuefeng; Liu, Lihua; Shen, Xinping; Wu, Zhe; Huang, Ke

    2017-10-01

    Data from 26 drill wells and 27 regional seismic profiles were integrated to investigate the timing, phase and origin of the post-rift subsidence in the middle to eastern Pearl River Mouth Basin (PRMB) of the northern South China Sea using the traditional 1-D backstripping technique. Different from previous research of backstripped tectonic subsidence in the basin, we calculated the tectonic subsidence using the newly built local porosity-depth relationships for decompaction and updated sedimentological and paleontological data for paleobathymetry reconstruction. Well-data based subsidence curves reveal a roughly decaying pattern in both the magnitude and rate of the post-rift subsidence in the PRMB, which is in accordance with the general decreasing trend of the thermal subsidence typical of a passive margin. Two events of rapid post-rift tectonic subsidence were identified, which occurred in the Early to early Middle Miocene and the Pliocene. The timing of the first rapid post-rift subsidence event varies and is earlier in the southern rather than northern part of the basin. Additionally, the amplitude of contemporaneous tectonic subsidence is greater in the southern part of the basin. The second rapid tectonic subsidence event occurred simultaneously in both the southern and northern parts of the basin, with the amplitude of subsidence being much greater in the southern part. We associate the first rapid subsidence event with the southward jump of the South China Sea spreading ridge, which occurred between the Oligocene and Early Miocene, while the second event with the arc-continent collision at Taiwan since the latest Late Miocene. The southern PRMB in the deep-water slope area shows a much higher magnitude of tectonic subsidence in both events than its northern counterpart in the shelf area, which could be associated with its much thinner lithosphere. The latter could cause upswelling of denser lower crust and upper mantle material, resulting in more rapid

  5. Rapid subsidence in damaging sinkholes: Measurement by high-precision leveling and the role of salt dissolution

    Science.gov (United States)

    Desir, G.; Gutiérrez, F.; Merino, J.; Carbonel, D.; Benito-Calvo, A.; Guerrero, J.; Fabregat, I.

    2018-02-01

    Investigations dealing with subsidence monitoring in active sinkholes are very scarce, especially when compared with other ground instability phenomena like landslides. This is largely related to the catastrophic behaviour that typifies most sinkholes in carbonate karst areas. Active subsidence in five sinkholes up to ca. 500 m across has been quantitatively characterised by means of high-precision differential leveling. The sinkholes occur on poorly indurated alluvium underlain by salt-bearing evaporites and cause severe damage on various human structures. The leveling data have provided accurate information on multiple features of the subsidence phenomena with practical implications: (1) precise location of the vaguely-defined edges of the subsidence zones and their spatial relationships with surveyed surface deformation features; (2) spatial deformation patterns and relative contribution of subsidence mechanisms (sagging versus collapse); (3) accurate subsidence rates and their spatial variability with maximum and mean vertical displacement rates ranging from 1.0 to 11.8 cm/yr and 1.9 to 26.1 cm/yr, respectively; (4) identification of sinkholes that experience continuous subsidence at constant rates or with significant temporal changes; and (5) rates of volumetric surface changes as an approximation to rates of dissolution-induced volumetric depletion in the subsurface, reaching as much as 10,900 m3/yr in the largest sinkhole. The high subsidence rates as well as the annual volumetric changes are attributed to rapid dissolution of high-solubility salts.

  6. Reducing subsidence risk by using rapid manufactured patient-specific intervertebral disc implants.

    Science.gov (United States)

    de Beer, Neal; Scheffer, Cornie

    2012-11-01

    Intervertebral disc implant size, shape, and position during total disc replacement have been shown to affect the risk of implant subsidence or vertebral fracture. Rapid manufacturing has been successfully applied to produce patient-specific implants for craniomaxillofacial, dental, hip, and knee requirements, but very little has been published on its application for spinal implants. This research was undertaken to investigate the improved load distribution and stiffness that can be achieved when using implants with matching bone interface geometry as opposed to implants with flat end plate geometries. The study design comprises a biomechanical investigation and comparison of compressive loads applied to cadaveric vertebrae when using two different end plate designs. Four spines from male cadavers (ages 45-65 years, average 52 years), which had a total of n=88 vertebrae (C3-L5), were considered during this study. Bone mineral density scans on each spine revealed only one to be eligible for this study. Twenty remaining vertebrae (C3-L3) were potted and subjected to nondestructive compression tests followed by destructive compression tests. Custom-made nonfunctional implants were designed for this experiment. Ten implants were designed with matching end plate-to-bone interface geometry, whereas the other 10 were designed with flat end plates. Testing did not incorporate the use of a keel in either design type. I-Scan pressure sensors (Tekscan, Inc., MA, USA) were used during the nondestructive tests to assess the load distribution and percentage surface contact. Average percent contact area measured during nondestructive tests was 45.27% and 10.49% for conformal and flat implants, respectively-a difference that is statistically significant (pbone end plate. Subsidence depends in part on the stiffness of the implant-bone construct, and with a 137% increase in stiffness, the results of this study show that there are indeed significant potential benefits that can be

  7. Rapid Cenozoic Subsidence in the Gulf of Mexico Resulting From Hess Rise Conjugate Subduction

    OpenAIRE

    Wang, Huilin; Gurnis, Michael; Skogseid, Jakob

    2017-01-01

    Enigmatic surface deflections occurred in North America starting from the Cretaceous, including the continental-scale drainage reorganization and the long-wavelength subsidence in the Western Interior Seaway. These surface undulations cannot be simply explained by sea level change or flexure loading. Coinciding with the large-scale surface deflection, the Gulf of Mexico (GOM) has an immense Paleocene sediment deposition probably caused by tectonic subsidence. Increasing evidence indicates a d...

  8. Rapid Cenozoic Subsidence in the Gulf of Mexico Resulting From Hess Rise Conjugate Subduction

    Science.gov (United States)

    Wang, Huilin; Gurnis, Michael; Skogseid, Jakob

    2017-11-01

    Enigmatic surface deflections occurred in North America starting from the Cretaceous, including the continental-scale drainage reorganization and the long-wavelength subsidence in the Western Interior Seaway. These surface undulations cannot be simply explained by sea level change or flexure loading. Coinciding with the large-scale surface deflection, the Gulf of Mexico (GOM) has an immense Paleocene sediment deposition probably caused by tectonic subsidence. Increasing evidence indicates a distinct seismic anomaly localized in the mantle below the GOM. With geodynamic models, we show that the Hess Rise conjugate coincides with the position of the seismic anomaly. The basalt-eclogite transition in the Hess conjugate can lead to a localized dynamic subsidence in the GOM, which is superimposed on the broad surface deflection caused by the Farallon slab. The Hess conjugate, transformed to eclogite, could tilt the surface southward in the U.S. and help frame the GOM as a main depocenter in the Cenozoic.

  9. Cultural Adaptations to Environmental Variability: An Evolutionary Account of East-West Differences

    Science.gov (United States)

    Chang, Lei; Mak, Miranda C. K.; Li, Tong; Wu, Bao Pei; Chen, Bin Bin; Lu, Hui Jing

    2011-01-01

    Much research has been conducted to document and sometimes to provide proximate explanations (e.g., Confucianism vs. Western philosophy) for East-West cultural differences. The ultimate evolutionary mechanisms underlying these cross-cultural differences have not been addressed. We propose in this review that East-West cultural differences (e.g.,…

  10. [East-West migration in Europe (1918-1993)].

    Science.gov (United States)

    Fassmann, H; Munz, R

    1995-01-01

    "This paper analyses available demographic data on international migration within and to Europe during the period 1918-1939 and 1945-1993. The main focus is on the east-west dimension of this migration. In the inter-war period some 9.2 million people either left their countries as labour migrants or were displaced.... In the post-war period (1945-1950) some 15.4 million people fled or were displaced within Europe.... Between 1950 and 1992 another 14 million people migrated from a country in East-central and Eastern Europe to the West.... In recent times the wars in Croatia and Bosnia as well as ethnic cleansing have led to the largest wave of refugees and displaced persons since 1945.... Our paper concludes that push and pull factors causing massive migration cannot only be contained by erecting new legislative barriers and deploying more armed border guards against newcomers." (SUMMARY IN ENG AND SPA) excerpt

  11. [East-West migration in Europe 1918-1992].

    Science.gov (United States)

    Fassmann, H; Munz, R

    1995-03-01

    "The paper [analyzes] available demographic data on international migration within and to Europe during the periods 1918-39 and 1945-92. The main focus is on the East-West dimension of this migration. In the inter-war period some 9.2 million people either left their countries as labour migrants or were displaced.... In the post-war period (1945-50) some 15.4 million people fled or were displaced within Europe. Most of them moved or were forced to move westwards.... In recent times the wars in Croatia and Bosnia as well as ethnic cleansing have led to the largest wave of refugees and displaced persons since 1945.... The paper argues that push and pull factors causing massive migration cannot...be contained by erecting new legislative barriers and deploying more armed guards against newcomers." (EXCERPT)

  12. Cold war, quantum foundations, and East-West collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Skaar-Jacobsen, Anja [Niels Bohr Archive, Copenhagen (Germany)

    2011-07-01

    It is well-known that the cultural cold war changed the ideological line in the Soviet Union from the late 1940s and that this had serious implications for the autonomy of research in genetics and quantum foundations in the East bloc. However, besides the more narrow concern from the point of view of research in quantum foundations, I suggest that the ideological impact on quantum foundations also constituted an obstacle for attempts by Western physicists to bring about a rapprochement between physics in the east and west in general. In connection with re-establishing East-West co-operation between physicists after Stalin's death in 1953 this obstacle needed to be cleared away. In my talk I discuss these issues and how the Institute for Theoretical Physics in Copenhagen came to be an important meeting place for physicists from the East and West from the mid-1950s.

  13. An integrated application of SAR interferometry and GRACE solution to land subsidence in a rapidly urbanizing groundwater dependent basin in Pakistan

    Science.gov (United States)

    Ahmad, Waqas; Kim, Soohyun; Kim, Dongkyun

    2017-04-01

    Land subsidence and crustal deformation associated with groundwater abstraction is a gradually instigating phenomenon. The exploitation of Interferometric Synthetic Aperture Radar (InSAR) for land subsidence velocity and the Gravity Recovery and Climate Experiment (GRACE) for change in groundwater storage have great potential besides other applications to address this problem. In this paper we used an integrated approach to combine InSAR and GRACE solutions to show that land subsidence velocity in a rapidly urbanizing and groundwater dependent basin in Pakistan is largely attributed to over exploitation of groundwater aquifer. We analyzed a total of 28 Sentinel-1 based interferograms generated for the period October 2014 to November 2016 to quantify the level of land subsidence in the study area. To increase the accuracy of our interferometry results we then applied a filter of Amplitude Dispersion Index (ADI) to confine the spatial extent of land subsidence to persistently scattering pixels. For the GRACE experiment we take the average of change in Total Water Storage (TWS) solutions provided by the Center for Space Research (CSR), the German Research Centre for Geosciences (GFZ), and the Jet Propulsion Laboratory (JPL) and validate this mean TWS for the study area using a network of observed time series groundwater levels. The validation result of GRACE TWS field shows that although the GRACE foot print is spatially larger than the extent of the study area but significant change in water storage can contribute to the overall trend of declining water storage. Finally we compared our results of InSAR land subsidence velocities and GRACE TWS change field. A strong dependence of the land subsidence on the temporal change in TWS suggests that most of the land subsidence could be attributed to the unchecked exploitation of groundwater aquifer.

  14. Tracing the origin of the east-west population admixture in the Altai region (Central Asia)

    National Research Council Canada - National Science Library

    González-Ruiz, Mercedes; Santos, Cristina; Jordana, Xavier; Simón, Marc; Lalueza-Fox, Carles; Gigli, Elena; Aluja, Maria Pilar; Malgosa, Assumpció

    2012-01-01

    A recent discovery of Iron Age burials (Pazyryk culture) in the Altai Mountains of Mongolia may shed light on the mode and tempo of the generation of the current genetic east-west population admixture in Central Asia...

  15. Wetlands & Deepwater Habitats - MO 2012 East West Gateway Wetland Restoration Rank (GDB)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Over the past five years, the East-West Gateway Council of Governments has facilitated creation of data layers to enhance conservation and transportation planning in...

  16. FUNCTIONING PECULIARITIES OF THE CONCEPTS OF NORTH, SOUTH, EAST, WEST IN JOHN CHEEVER’S WORKS

    OpenAIRE

    КРАСНИЦЬКА, Катерина Вікторівна

    2017-01-01

    The purpose of this article is the analysis of the verbalized concepts EAST, WEST, SOUTH, NORTH in the individual world image of a contemporary American writer John Cheever. The object of the present study are the individual image and axiological associations and also unique semantic components of the concepts EAST, WEST, SOUTH, NORTH, that are immanent to the conceptual world-image of the writer John Cheever and are refl ected in his works. The subject of the study are the lexemes that verba...

  17. East-West Epistemological Convergence of Humanism in Language, Identity, and Education: Confucius-Makiguchi-Dewey

    Science.gov (United States)

    He, Ming Fang

    2013-01-01

    In this article, the author explores an East-West epistemological convergence of humanism illuminated in three main themes in the works of Confucius (551-479 BC), Makiguchi Tsunesaburo (1871-1944), and John Dewey (1859-1952): "human-nature interconnection," "associated self-cultivation," and "value creation." She contends that these thinkers'…

  18. Reentrainment of the circadian pacemaker during jet lag: East-west asymmetry and the effects of north-south travel.

    Science.gov (United States)

    Diekman, Casey O; Bose, Amitabha

    2018-01-21

    The normal alignment of circadian rhythms with the 24-h light-dark cycle is disrupted after rapid travel between home and destination time zones, leading to sleep problems, indigestion, and other symptoms collectively known as jet lag. Using mathematical and computational analysis, we study the process of reentrainment to the light-dark cycle of the destination time zone in a model of the human circadian pacemaker. We calculate the reentrainment time for travel between any two points on the globe at any time of the day and year. We construct one-dimensional entrainment maps to explain several properties of jet lag, such as why most people experience worse jet lag after traveling east than west. We show that this east-west asymmetry depends on the endogenous period of the traveler's circadian clock as well as daylength. Thus the critical factor is not simply whether the endogenous period is greater than or less than 24 h as is commonly assumed. We show that the unstable fixed point of an entrainment map determines whether a traveler reentrains through phase advances or phase delays, providing an understanding of the threshold that separates orthodromic and antidromic modes of reentrainment. Contrary to the conventional wisdom that jet lag only occurs after east-west travel across multiple time zones, we predict that the change in daylength encountered during north-south travel can cause jet lag even when no time zones are crossed. Our techniques could be used to provide advice to travelers on how to minimize jet lag on trips involving multiple destinations and a combination of transmeridian and translatitudinal travel. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. YUCCA MOUNTAIN SITE CHARACTERIZATION PROJECT EAST-WEST DRIFT SYSTEM SAFETY ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    NA

    1999-06-08

    The purpose of this analysis is to systematically identify and evaluate hazards related to the design of the Yucca Mountain Project Exploratory Studies Facility (ESF) East-West Cross Drift. This analysis builds upon prior ESF System Safety Analyses and incorporates TS Main Drift scenarios, where applicable, into the East-West Drift scenarios. This System Safety Analysis (SSA) focuses on the personnel safety and health hazards associated with the engineered design of the East-West Drift. The analysis also evaluates other aspects of the East-West Drift, including purchased equipment (e.g., scientific mapping platform) or Systems/Structures/Components (SSCs) and out-of-tolerance conditions. In addition to recommending design mitigation features, the analysis identifies the potential need for procedures, training, or Job Safety Analyses (JSAs). The inclusion of this information in the SSA is intended to assist the organization(s) (e.g., constructor, Safety and Health, design) responsible for these aspects of the East-West Drift in evaluating personnel hazards and augment the information developed by these organizations. The SSA is an integral part of the systems engineering process, whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach is used which incorporates operating experiences and recommendations from vendors, the constructor and the operating contractor. The risk assessment in this analysis characterizes the scenarios associated with East-West Drift SSCs in terms of relative risk and includes recommendations for mitigating all identified hazards. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into SSC designs. (2) Add safety features and capabilities to existing designs. (3) Develop procedures and conduct training to increase worker awareness of potential hazards, reduce exposure to hazards, and inform personnel of the

  20. Tracing the Origin of the East-West Population Admixture in the Altai Region (Central Asia): e48904

    National Research Council Canada - National Science Library

    Mercedes González-Ruiz; Cristina Santos; Xavier Jordana; Marc Simón; Carles Lalueza-Fox; Elena Gigli; Maria Pilar Aluja; Assumpció Malgosa

    2012-01-01

      A recent discovery of Iron Age burials (Pazyryk culture) in the Altai Mountains of Mongolia may shed light on the mode and tempo of the generation of the current genetic east-west population admixture in Central Asia...

  1. East-west extension and Holocene normal-fault scarps in the Hellenic arc

    Science.gov (United States)

    Armijo, R.; Lyon-Caen, H.; Papanastassiou, D.

    1992-06-01

    Examination of surface fault traces with Spot images and in the field corroborates the inference that the active tectonics of southern Peloponnesus and Crete are dominated by approximately north-south normal faulting and approximately east-west extension. The heights of Holocene normal-fault scarps yield first-order regional estimates of fault slip rates between 0.1 and 2-3 mm/yr. Most of the surface scarps probably ruptured during past earthquakes, such as that which destroyed Sparta in 464 B.C. On the Sparta fault the Holocene average slip rate and the recurrence time of large earthquakes may be ˜1 mm/yr and 3000 yr, respectively. The regional pattern of Quaternary faulting suggests that the east-west extension near the Hellenic subduction zone is fast (about 5%-10%/m.y.). The change from north-south to east-west extension in the late Pliocene (˜2-4 Ma) implies that the Aegean is starting to collide with the northern margin of Africa.

  2. Climate sensitivity of Mediterranean pine growth reveals distinct east-west dipole

    Czech Academy of Sciences Publication Activity Database

    Seim, A.; Treydte, K.; Trouet, V.; Frank, D.; Fonti, P.; Tegel, W.; Panayotov, M.; Fernandez-Donado, L.; Krusic, P.; Büntgen, Ulf

    2015-01-01

    Roč. 35, č. 9 (2015), s. 2503-2513 ISSN 0899-8418 R&D Projects: GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : tree-ring width * scots pine * wood formation * ice core * variability * drought * precipitation * reconstructions * circulation * dynamics * climate dynamics * dendroclimatology * drought response * Mediterranean east-west dipole * palaeoclimatology * Pinus spp * principal component analysis * tree-ring width Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.609, year: 2015

  3. PROSPECTS OF INTERNATIONAL FREIGHT TRANSPORT IN THE EAST-WEST DIRECTION

    Directory of Open Access Journals (Sweden)

    Paweł DROŹDZIEL

    2015-12-01

    Full Text Available The article deals with the assets of building broad-gauge lines in Europe. The delivery time for international transport of goods affects international business in terms of the capital put into goods and subsequently affects its turnover rate. The current disproportion of different line gauges in Europe causes significant problems in the transport of goods especially in commodity streams in the East - West direction. Based on previous research of commodity streams in international trade and a comprehensive analysis of all performed studies for building broad gauge lines, the assets of building these lines included the development of employment, increasing the transport capacity and the building of transshipment stations in Slovakia. The current geopolitical developments have also a significant impact on international transport and important transport links, therefore diversifying these risks is a logical consideration to ensure the smooth delivery of goods and thus the development of international trade.

  4. Tracing the origin of the east-west population admixture in the Altai region (Central Asia.

    Directory of Open Access Journals (Sweden)

    Mercedes González-Ruiz

    Full Text Available A recent discovery of Iron Age burials (Pazyryk culture in the Altai Mountains of Mongolia may shed light on the mode and tempo of the generation of the current genetic east-west population admixture in Central Asia. Studies on ancient mitochondrial DNA of this region suggest that the Altai Mountains played the role of a geographical barrier between West and East Eurasian lineages until the beginning of the Iron Age. After the 7th century BC, coinciding with Scythian expansion across the Eurasian steppes, a gradual influx of East Eurasian sequences in Western steppes is detected. However, the underlying events behind the genetic admixture in Altai during the Iron Age are still unresolved: 1 whether it was a result of migratory events (eastward firstly, westward secondly, or 2 whether it was a result of a local demographic expansion in a 'contact zone' between European and East Asian people. In the present work, we analyzed the mitochondrial DNA lineages in human remains from Bronze and Iron Age burials of Mongolian Altai. Here we present support to the hypothesis that the gene pool of Iron Age inhabitants of Mongolian Altai was similar to that of western Iron Age Altaians (Russia and Kazakhstan. Thus, this people not only shared the same culture (Pazyryk, but also shared the same genetic east-west population admixture. In turn, Pazyryks appear to have a similar gene pool that current Altaians. Our results further show that Iron Age Altaians displayed mitochondrial lineages already present around Altai region before the Iron Age. This would provide support for a demographic expansion of local people of Altai instead of westward or eastward migratory events, as the demographic event behind the high population genetic admixture and diversity in Central Asia.

  5. East-West gradient in the incidence of inflammatory bowel disease in Europe

    DEFF Research Database (Denmark)

    Burisch, J; Pedersen, Natalia; Čuković-Čavka, S

    2014-01-01

    OBJECTIVE: The incidence of inflammatory bowel disease (IBD) is increasing in Eastern Europe. The reasons for these changes remain unknown. The aim of this study was to investigate whether an East-West gradient in the incidence of IBD in Europe exists. DESIGN: A prospective, uniformly diagnosed......, population based inception cohort of IBD patients in 31 centres from 14 Western and eight Eastern European countries covering a total background population of approximately 10.1 million people was created. One-third of the centres had previous experience with inception cohorts. Patients were entered...... (11%) with IBD unclassified (IBDU). The overall incidence rate ratios in all Western European centres were 1.9 (95% CI 1.5 to 2.4) for CD and 2.1 (95% CI 1.8 to 2.6) for UC compared with Eastern European centres. The median crude annual incidence rates per 100,000 in 2010 for CD were 6.5 (range 0...

  6. Siim Nestor soovitab : Acid Mothers Temple. Dzhäss ja "tõsidus" NYYD Ensemble ilt. Garage, this is paradise. East-West / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2002-01-01

    Jaapani megaorkestri AMT esinemisest Linnakultuurifestivali üritusel "Operation B" Von Krahlis 8. nov. Estonia kontserdisaalis toimuvast ansambli NYYD kontserdist 11. nov. Klubis Wimbledon 8. nov. toimuvast peost "Garage, this is paradise". Saku Suurhallis toimuvast peost "East West"

  7. Simulation of geothermal subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Miller, I.; Dershowitz, W.; Jones, K.; Myer, L.; Roman, K.; Schauer, M.

    1980-03-01

    The results of an assessment of existing mathematical models for subsidence simulation and prediction are summarized. The following subjects are discussed: the prediction process, physical processes of geothermal subsidence, computational models for reservoir flow, computational models for deformation, proficiency assessment, and real and idealized case studies. (MHR)

  8. Thermokarst Caves, Baydzherakhs, and Thaw Subsidence, Oh My! Combining Ground Based Geophysics and Survey Measurements With Airborne LiDAR to Understand Rates and Patterns of Rapid Permafrost Thaw

    Science.gov (United States)

    Douglas, T. A.; Hiemstra, C. A.; Bjella, K.

    2016-12-01

    Arctic and sub-Arctic discontinuous permafrost regions are nearing thaw instability. Warming temperatures, human or natural disturbance, altered precipitation, or a shift in the timing of seasonal transitions can lead to dramatic landscape changes on timescales of a few years. Much of the permafrost thaw surface expression is controlled by melting subsurface ice features, and these "hot spot" locations are currently not specifically mapped and are likely increasing in number and areal distribution. Tools are needed to identify where, how, and at what rate thermokarst, thaw subsidence, and altered hydrologic flowpaths develop. Galvanic coupled resistivity tomography (GRT) allows for an indirect qualitative identification of permafrost; frozen versus thawed, and ice-rich versus ice-poor. When GRT is combined with aboveground repeat imagery and LiDAR spatial information, permafrost landscape change can be detected and rates and scales of this change ascertained. This can also be combined with vegetation and ecological measurements to identify how rapidly subsurface changes in permafrost alter hydrologic and biogeochemical cycles. We are combining GRT, borehole mapping, airborne and ground-based LiDAR, and snow, soil, and vegetation measurements at a variety of Interior Alaska locations where permafrost landscapes have been exhibiting rapid change. Our features include an area where hillslope erosion developed subsurface thermokarst caverns meters deep and tens of meters long following intense summer precipitation events. We are studying thermokarst at a 600-m long lake that rapidly drained to expose a field of baydzherakhs meters tall and 5-10 meter across. We have also been monitoring rapid degradation and subsidence in lowland ice rich permafrost. The results from this study suggest the expression of permafrost degradation and thermokarst formation across the landscape are readily apparent and quantifiable. Baseline and recurrent surveying with these coupled

  9. Data Acquisition for Land Subsidence Control

    Science.gov (United States)

    Zhu, Y.; Balke, K.

    2009-12-01

    For controlling land subsidence caused by groundwater over-exploitation, loading of engineered structures, mining and other anthropogenic activities in this fast changing world, a large variety of different data of various scales of concerning areas are needed for scientific study and administrative operational purposes. The economical, social and environmental impacts of anthropogenic land subsidence have long been recognized by many scientific institutions and management authorities based on results of monitoring and analysis at an interdisciplinary level. The land subsidence information systems composed of the surface and subsurface monitoring nets (monitoring and development wells, GPS stations and other facilities) and local data processing centers as a system management tool in Shanghai City was started with the use of GPS technology to monitor land subsidence in 1998. After years of experiences with a set of initiatives by adopting adequate countermeasures, the particular attention given to new improved methodologies to monitor and model the process of land subsidence in a simple and timely way, this is going to be promoted in the whole Yangtze River Delta region in China, where land subsidence expands in the entire region of urban cluster. The Delta land subsidence monitoring network construction aims to establish an efficient and coordinated water resource management system. The land subsidence monitoring network records "living history" of land subsidence, produces detailed scheduled reports and environmental impact statements. For the different areas with local factors and site characteristics, parallel packages need to be designed for predicting changes, land sensitivity and uncertainty analysis, especially for the risk analysis in the rapid growth of megacities and urban areas. In such cases, the new models with new types of local data and the new ways of data acquisition provide the best information for the decision makers for their mitigating

  10. The contribution of alcohol to the East-West life expectancy gap in Europe from 1990 onward.

    Science.gov (United States)

    Trias-Llimós, Sergi; Kunst, Anton E; Jasilionis, Domantas; Janssen, Fanny

    2017-12-08

    Central and Eastern European (CEE) countries have lower life expectancies and higher alcohol-attributable mortality than Western European countries. We examine the contribution of alcohol consumption to mortality across Europe, and specifically to the East-West life expectancy gap from 1990 onward. We retrieved alcohol-attributable mortality rates (GBD Study 2013) and all-cause mortality rates (Human Mortality Database) by age and sex for nine CEE countries and for the EU-15 countries. We assessed country-specific potential gains in life expectancy (PGLE) by eliminating alcohol-attributable mortality using associated single decrement life tables. We decomposed the life expectancy differences between each CEE country and the EU-15 population-weighted average for 1990-2012/13 into alcohol-attributable and non-alcohol-attributable mortality. In 2012/13, the PGLE for men and women were, respectively, 2.15 and 1.00 years in the CEE region and 0.90 and 0.44 years in the EU-15 region. The contribution of alcohol to the East-West gap in life expectancy was largest among men in Russia {2.88 years [uncertainty interval (UI): 1.57-4.06]}, Belarus [3.70 years (UI: 1.75-5.45)] and Ukraine [2.47 years (UI: 0.90-3.88)]. The relative contributions increased in most of the countries between 1990 and 2005 (on average, from 17.0% to 25.4% for men, and from 14.7% to 22.5% for women), and declined thereafter (20.2% for men and 20.5% for women in 2012/13). Alcohol contributed substantially to the East-West life expectancy gap in Europe, and to its increase (1990-2005) and decline (2005 onward). Diminishing alcohol consumption in CEE countries to Western European levels can contribute to mortality convergence across Europe.

  11. Internal Migration, Regional Labour Market Dynamics and Implications for German East-West Disparities – Results from a Panel VAR

    DEFF Research Database (Denmark)

    Alecke, Björn; Mitze, Timo; Untiedt, Gerhard

    This paper analyses the causal linkages between regional labour market variables and internal migration flows among German states between 1991–2006. We adopt a Panel VAR approach to identify the feedback effects among the variables and analyse the dynamic properties of the system through...... impulseresponse functions.We also use the model to track the evolution of the particular East-West migration since re-unification aiming to shed more light on the East German “empirical puzzle”, characterized by lower migration responses than expected from the regional labour market position relative to the West......, this supports the view of “repressed” migration flows for that period....

  12. Space geodesy: subsidence and flooding in New Orleans.

    Science.gov (United States)

    Dixon, Timothy H; Amelung, Falk; Ferretti, Alessandro; Novali, Fabrizio; Rocca, Fabio; Dokka, Roy; Sella, Giovanni; Kim, Sang-Wan; Wdowinski, Shimon; Whitman, Dean

    2006-06-01

    It has long been recognized that New Orleans is subsiding and is therefore susceptible to catastrophic flooding. Here we present a new subsidence map for the city, generated from space-based synthetic-aperture radar measurements, which reveals that parts of New Orleans underwent rapid subsidence in the three years before Hurricane Katrina struck in August 2005. One such area is next to the Mississippi River-Gulf Outlet (MRGO) canal, where levees failed during the peak storm surge: the map indicates that this weakness could be explained by subsidence of a metre or more since their construction.

  13. Microcnemum coralloides (Chenopodiaceae- Salicornioideae: an example of intraspecific East-West disjunctions in the Mediterranean region

    Directory of Open Access Journals (Sweden)

    Kadereit, Gudrun

    2008-12-01

    Full Text Available Microcnemum is a monotypic genus of Salicornioideae comprising rare, annual, hygrohalophytic herbs growing in hypersaline inland lagoons and salt pans. Microcnemum coralloides shows an East-West disjunction in the Mediterranean region: M. coralloides subsp. coralloides occurs in central and eastern Spain while M. coralloides subsp. anatolicum grows in Turkey, Syria, Armenia and Iran. We studied the phylogeny, biogeography and morphological differentiation of M. coralloides. Molecular analyses, using five western and eight eastern accessions of the species, were based on three different markers (nuclear ITS and plastid atpB-rbcL spacer and trnT/F region analysed with Maximum Parsimony and Maximum Likelihood. Estimates of divergence times were calculated using a Likelihood Ratio Test (LRT and the Penalized Likelihood (PL method. The two subspecies can be clearly distinguished by their different seed testa surface. Other diagnostic characters were not found. The molecular data (ITS and ML analysis of the trnT/F region indicate that M. coralloides subsp. coralloides originated from within M. coralloides subsp. anatolicum which implies an East Mediterranean origin and subsequent westward dispersal. Age estimates for the split of the two subspecies range from 2.8–0.5 million years ago. Considering the relatively low genetic differentiation and the low crown group age (0.7–0.1 mya of M. coralloides subsp. coralloides in comparison to M. coralloides subsp. anatolicum we favour the hypothesis that the Iberian part of the species range was established during cold periods of the Early Pleistocene and that the range of the species was fragmented during a warmer period soon after its arrival in Iberia.Microcnemum es un género monotípico de Salicornioideae que consiste en hierbas higrohalófilas, anuales, raras, que crecen en cuencas endorréicas hipersalinas del interior y salares. Microcnemum coralloides muestran una disyunción Este

  14. Book review of Cristian Nünlist and David Svarin (eds.) Overcoming the East-West Divide: Perspectives on the Role of the OSCE in the Ukraine Crisis

    NARCIS (Netherlands)

    Kraft van Ermel, Nicolaas

    2014-01-01

    In 2014 Europe’s security configuration had to deal with a severe crisis. Events in Ukraine led to a situation of civil war in Ukraine and a further development of the East-West Divide between (Western) Europe and Russia. During 2014 most attention was given to international actors like the North

  15. Avian utilization of subsidence wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Nawrot, J.R.; Conley, P.S.; Smout, C.L. [Southern Illinois Univ., Carbondale, IL (United States)

    1995-09-01

    Diverse and productive wetlands have resulted from coal mining in the midwest. The trend from surface to underground mining has increased the potential for subsidence. Planned subsidence of longwall mining areas provides increased opportunities for wetland habitat establishment. Planned subsidence over a 180 meter (590 foot) deep longwall mine in southern Illinois during 1984 to 1986 produced three subsidence wetlands totaling 15 hectares (38 acres). The resulting palustrine emergent wetlands enhanced habitat diversity within the surrounding palustrine forested unsubsided area. Habitat assessments and evaluations of avian utilization of the subsidence wetlands were conducted during February 1990 through October 1991. Avian utilization was greatest within the subsided wetlands. Fifty-three bird species representing seven foraging guilds utilized the subsidence wetlands. Wading/fishing, dabbling waterfowl, and insectivorous avian guilds dominated the subsidence wetlands. The subsidence wetlands represented ideal habitat for wood ducks and great blue herons which utilized snags adjacent to and within the wetlands for nesting (19 great blue heron nests produced 25 young). Dense cover and a rich supply of macroinvertebrates provide excellent brood habitat for wood ducks, while herpetofauna and ichthyofauna provided abundant forage in shallow water zones for great blue herons and other wetland wading birds. The diversity of game and non-game avifauna utilizing the subsidence areas demonstrated the unique value of these wetlands. Preplanned subsidence wetlands can help mitigate loss of wetland habitats in the midwest.

  16. East-West, Collectivist-Individualist: A Cross-Cultural Examination of Temperament in Toddlers from Chile, Poland, South Korea, and the U.S

    Science.gov (United States)

    Krassner, Ariye M.; Gartstein, Maria A.; Park, Curie; Dragan, Wojciech Ł.; Lecannelier, Felipe; Putnam, Samuel P.

    2017-01-01

    The present study examined toddler temperament across Chilean, South Korean, Polish, and US samples, providing an opportunity to examine both collectivist-individualist and East-West contrasts. The effect of culture on the three factor and 18 dimension scores provided by the Early Childhood Behavior Questionnaire were investigated. Results provide evidence of cross-cultural differences between the four samples. Chilean toddlers scored significantly higher than US, Polish, and South Korean children on the overall factor of Negative Affectivity, as well as higher than the Polish and South Korean samples on the Surgency factor. South Korean toddlers scored significantly higher on the factor of Effortful Control, and two related dimensions, than US, Polish, or Chilean samples. Results are discussed in terms of the apparent roles of individualism/collectivism and East-West distinctions in shaping temperament development. PMID:29333175

  17. The importance of father's and own education for self-assessed health across Europe: an East-West divide?

    Science.gov (United States)

    Monden, Christiaan W S; de Graaf, Nan Dirk

    2013-09-01

    How are one's own education, father's education, and especially the combination of the two, related to self-assessed health across European societies? In this study, we test hypotheses about differences in self-assessed health between 16 post-socialist countries in Central and Eastern Europe and 17 Western European countries. We find substantial cross-national variation in the (relative) importance of own and father's education for self-assessed health. Over 65 per cent of this cross-national variation is accounted for by the East-West divide. This simple dichotomy explains cross-national differences better than gross domestic product or income inequality. An individual's father's education is more important, both in absolute and relative terms, for self-assessed heath in Eastern Europe than in Western Europe. Intergenerational mobility moderates the relative effects of one's own and one's father's education. In Eastern Europe the relative importance of one's father's education is greater than it is in Western Europe--particularly for those who are downwardly mobile and have a father with tertiary education. The results are sometimes contradictory to initial expectations; the theoretical implications are discussed. © 2012 The Authors. Sociology of Health & Illness © 2012 Foundation for the Sociology of Health & Illness/JohnWiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  18. Wind wave spectra and meteorological data from moored buoys from the East/West coasts of US and other locations from 01 December 2001 to 31 December 2001 (NODC Accession 0000685)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from the East/West coasts of US, South Pacific Ocean, Gulf of Mexico, and the Great Lakes. Data were...

  19. Wind wave spectra and meteorological data from moored buoys from East/West coasts of US and other locations from 01 January 2002 to 31 January 2002 (NODC Accession 0000686)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from the East/West coasts of US, South Pacific Ocean, Gulf of Mexico, and the Great Lakes. Data were...

  20. Wind wave spectra and meteorological data from moored buoys from the East/West coasts of US and other locations from 01 April 2001 to 30 April 2001 (NODC Accession 0000460)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from the East/West coast of US, South Pacific, Gulf of Mexico, Great Lakes and other locations. Data were...

  1. Wind wave spectra and meteorological data from moored buoys from the East/West coasts of US and other locations from 01 October 2001 to 31 October 2001 (NODC Accession 0000682)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from the East/West coasts of US, South Pacific Ocean, Gulf of Mexico, and the Great Lakes. Data were...

  2. Wind Wave Spectra and meteorological data from NOAA environmental moored buoys in the Gulf of Mexico, Great Lakes. East/West coasts of US and other locations from 01 June 2001 to 30 June 2001 (NODC Accession 0000530)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from the East/West coast of US, Gulf of Mexico, and the Great Lakes. Data were collected from NOAA...

  3. Wind wave spectra and meteorological data from moored buoys from the East/West coasts of US and other locations from 01 February 2001 to 28 February 2001 (NODC Accession 0000415)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from the East/West coast of US, South Pacific, Gulf of Mexico, and the Great Lakes. Data were collected from...

  4. Wind wave spectra and meteorological data from moored buoys from East/West coasts of US and other locations from 01 November 2001 to 30 November 2001 (NODC Accession 0000683)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from the East/West coasts of US, South Pacific Ocean, Gulf of Mexico, and the Great Lakes. Data were...

  5. Thermal comfort in an east-west oriented street canyon in Freiburg (Germany) under hot summer conditions

    Science.gov (United States)

    Ali-Toudert, F.; Mayer, H.

    2007-01-01

    Field-measurements were conducted in an urban street canyon with an east-west orientation, and a height-to-width ratio H/W = 1 during cloudless summer weather in 2003 in Freiburg, Germany. This experimental work adds to the knowledge available on the microclimate of an urban canyon and its impact on human comfort. Air temperature T a , air humidity VP, wind speed v and direction dd were measured continuously. All short-wave and long-wave radiation fluxes from the 3D surroundings were also measured. The degree of comfort was defined in terms of physiologically equivalent temperature (PET). Furthermore, the data gathered within the canyon were compared to data collected by a permanent urban climate station with the aim of furthering the understanding of microclimatic changes due to street geometry. Changes in the meteorological variables T a , v and dd in the canyon in comparison to an unobstructed roof level location were found to be in good agreement with previous studies, i.e., a small increase of T a in the canyon adjacent to irradiated surfaces, and a good correlation of v and dd between canyon and roof levels. The daily dynamics of canyon facet irradiances and their impacts on the heat gained by a pedestrian were strongly dependent on street geometry and orientation. Thermal stress was mostly attributable to solar exposure. Under cloudless summer weather, a standing body was found to absorb, on average, 74% of heat in the form of long-wave irradiance and 26% as short-wave irradiance. Shading the pedestrian as well as the surrounding surfaces is, hence, the first strategy in mitigating heat stress in summer under hot conditions.

  6. An integrated assessment framework for land subsidence in delta cities

    Directory of Open Access Journals (Sweden)

    T. H. M. Bucx

    2015-11-01

    Full Text Available In many delta cities land subsidence exceeds absolute sea level rise up to a factor of ten by excessive groundwater extraction related to rapid urbanization and population growth. Without change, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other delta (and coastal cities will sink below sea level. Increased flooding and also other widespread impacts of land subsidence result already in damage of billions of dollars per year. In order to gain insight in the complex, multi-sectoral aspects of subsidence, to raise awareness and to support decision making on appropriate adaptation strategies and measures, an Integrated Assessment Framework (IAF for subsidence is introduced, illustrated by several (delta case studies. Based on that a list of 10 generic key issues and possible solutions is presented in order to further develop and support a (generic approach how to deal with subsidence in current and future subsidence-prone areas. For exchange of experiences and knowledge development.on subsidence in deltas the Delta Alliance, a knowledge network of deltas worldwide, can be supportive.

  7. The interaction between land subsidence and urban development in China

    Directory of Open Access Journals (Sweden)

    Y. Yang

    2015-11-01

    Full Text Available The Yangtze River Delta and North China Plain are experiencing serious land subsidence development and are also the areas that have undergone the fastest urbanization. Rapid urban development inevitably requires more water resources. However, China is a country with small per capita water resources, nonuniform distribution of water resources, and over-exploitation of groundwater – all of which are critical factors contributing to the potential for a land subsidence disaster. In addition, land subsidence has brought about elevation loss, damaged buildings, decreased safety of rail transit projects, lowered land value, and other huge economic losses and potential safety hazards in China. In this paper, Beijing, a typical northern Chinese city deficient in water, is taken as an example to explore (a the problems of urban development, utilization of water resources, and land subsidence development; (b the harm and influence of land subsidence hazards on urban construction; and (c the relationship between urban development and land subsidence. Based on the results, the author has predicted the trend of urban development and land subsidence in Beijing and puts forward her viewpoints and suggestions.

  8. How to deal with subsidence in the Dutch delta?

    Science.gov (United States)

    Stouthamer, Esther; Erkens, Gilles

    2017-04-01

    In many deltas worldwide subsidence still is an underestimated problem, while the threat posed by land subsidence to low-lying urbanizing and urbanized deltas exceeds the threat of sea-level rise induced by climate change. Human-induced subsidence is driven by the extraction of hydrocarbons and groundwater, drainage of phreatic groundwater, and loading by buildings and infrastructure. The consequences of subsidence are increased flood risk and flood water depth, rising groundwater levels relative to the land surface, land loss, damage to buildings and infrastructure, and salinization of ground and surface water.. The Netherlands has a long history of subsidence. Large-scale drainage of the extensive peatlands in the western and northern parts of the Netherlands started approximately 1000 years ago as a result of rapid population growth. Subsidence is still ongoing due to (1) continuous drainage of the former peatland, which is now mainly in use as agricultural land and built-up area, (2) expansion of the built-up area and the infrastructural network, (3) salt mining and the extraction of gas in the northern Netherlands. Mitigating subsidence and its negative impacts requires understanding of the relative contribution of the drivers contributing to total subsidence, accurate predictions of land subsidence under different management scenarios, and its impacts. Such understanding enables the development of effective and sustainable management strategies. In the Netherlands, a lot of effort is put into water management aiming at amongst others the protection against floods and the ensuring agricultural activities, but a specific policy focusing on subsidence is lacking. The development of strategies to cope with subsidence is very challenging, because (1) the exact contribution of different drivers of subsidence to total subsidence is spatially different within the Netherlands, (2) there is no single problem owner, which makes it difficult to recognize this a common

  9. Mobile assessment of on-road air pollution and its sources along the East-West Highway in Bhutan

    Science.gov (United States)

    Wangchuk, Tenzin; Knibbs, Luke D.; He, Congrong; Morawska, Lidia

    2015-10-01

    Human exposures in transportation microenvironments are poorly represented by ambient stationary monitoring. A number of on-road studies using vehicle-based mobile monitoring have been conducted to address this. Most previous studies were conducted on urban roads in developed countries where the primary emission source was vehicles. Few studies have examined on-road pollution in developing countries in urban settings. Currently, no study has been conducted for roadways in rural environments where a substantial proportion of the population live. This study aimed to characterize on-road air quality on the East-West Highway (EWH) in Bhutan and identify its principal sources. We conducted six mobile measurements of PM10, particle number (PN) count and CO along the entire 570 km length of the EWH. We divided the EWH into five segments, R1-R5, taking the road length between two district towns as a single road segment. The pollutant concentrations varied widely along the different road segments, with the highest concentrations for R5 compared with other road segments (PM10 = 149 μg/m3, PN = 5.74 × 104 particles/cm-3, CO = 0.19 ppm), which is the final segment of the road to the capital. Apart from vehicle emissions, the dominant sources were road works, unpaved roads and roadside combustion activities. Overall, the highest contributions above the background levels were made by unpaved roads for PM10 (6 times background), and vehicle emissions for PN and CO (5 and 15 times background, respectively). Notwithstanding the differences in instrumentation used and particle size range measured, the current study showed lower PN concentrations compared with similar on-road studies. However, concentrations were still high enough that commuters, road maintenance workers and residents living along the EWH, were potentially exposed to elevated pollutant concentrations from combustion and non-combustion sources. Future studies should focus on assessing the dispersion patterns of

  10. Changing theory, changing role of Coriolis effect - The East-West asymmetry of the Wadati-Benioff seismic zones

    Science.gov (United States)

    Scalera, Giancarlo

    2014-05-01

    the assumptions implicit in the adopted geodynamic theory, or in other words, by adopting a different theory of global geodynamics, the role of the fictitious inertial forces can become substantial. In a different framework Coriolis effect value can rise of several magnitude orders, becoming the main cause of the east-west asymmetry of the Wadati-Benioff zones, which might be ascribed entirely to internal causes of the planet (its rotation) and not to external causes (influence of other celestial bodies). Some clues supporting the new geodynamic scenario are scrutinized.

  11. Right: Left:: East: West. Evidence that individuals from East Asian and South Asian cultures emphasize right hemisphere functions in comparison to Euro-American cultures.

    Science.gov (United States)

    Rozin, Paul; Moscovitch, Morris; Imada, Sumio

    2016-09-01

    We present evidence that individuals from East or South Asian cultures (Japanese college students in Japan and East or South Asian born and raised college students in the USA) tend to exhibit default thinking that corresponds to right hemisphere holistic functions, as compared to Caucasian individuals from a Western culture (born and raised in the USA). In two lateralized tasks (locating the nose in a scrambled face, and global-local letter task), both Asian groups showed a greater right hemisphere bias than the Western group. In a third lateralized task, judging similarity in terms of visual form versus functional/semantic categorizations, there was not a reliable difference between the groups. On a classic, ambiguous face composed of vegetables, both Eastern groups displayed a greater right hemisphere (holistic face processing) bias than the Western group. These results support an "East - Right Hemisphere, West - Left Hemisphere" hypothesis, as originally proposed by Ornstein (1972). This hypothesis is open as to the degree to which social-cultural forces were involved in hemispheric specialization, or the opposite, or both. Our aim is to encourage a more thorough analysis of this hypothesis, suggesting both lateralization studies corresponding to documented East-West differences, and East-West studies corresponding to lateralization differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Spatial-temporal variation of groundwater and land subsidence evolution in Beijing area

    Directory of Open Access Journals (Sweden)

    K. Lei

    2015-11-01

    Full Text Available Precipitation is the main recharge source of groundwater in the plain of Beijing, China. Rapid expansion of urbanization has resulted in increased built-up area and decreased amount of effective recharge of precipitation to groundwater, indirectly leading to the long-term over-exploitation of groundwater, and induced regional land subsidence. Based on the combination of meteorological data, groundwater level data, interferometric synthetic aperture radar (InSAR; specifically persistent scatterer interferometry, PSI, geographic information system (GIS spatial analysis method and rainfall recharge theory, this paper presents a systematic analysis of spatial-temporal variation of groundwater level and land subsidence evolution. Results show that rainfall has been decreasing annually, while the exploitation of groundwater is increasing and the groundwater level is declining, which is has caused the formation and evolution of land subsidence. Seasonal and interannual variations exist in the evolution of land subsidence; the subsidence is uneven in both spatial and temporal distribution. In 2011, at the center of mapped subsidence the subsidence rate was greater than 120 mm a−1. The results revealed good correlation between the spatial distribution of groundwater level declines and subsidence. The research results show that it is beneficial to measure the evolution of land subsidence to dynamic variations of groundwater levels by combining InSAR or PSI, groundwater-level data, and GIS. This apprpach provides improved information for environmental and hydrogeologic research and a scientific basis for regional land subsidence control.

  13. Subsidizing R&D cooperatives

    NARCIS (Netherlands)

    Hinloopen, J.

    2001-01-01

    A framework is developed with which the implementation of two commonly used R&D-stimulating policies can be evaluated: providing R&D subsidies and sustaining the formation of R&D cooperatives. Subsidized R&D cooperatives can also be analyzed. The analysis shows that providing R&D subsidies is more

  14. A Picture of Subsidized Housholds 2008

    Data.gov (United States)

    Department of Housing and Urban Development — Picture of Subsidized Households describes the nearly 5 million households living in HUD-subsidized housing in the United States for the year 2008. Picture 2008...

  15. A Picture of Subsidized Households 2009

    Data.gov (United States)

    Department of Housing and Urban Development — Picture of Subsidized Households describes the nearly 5 million households living in HUD-subsidized housing in the United States for the year 2009. Picture 2009...

  16. VLF modal interference distance and nighttime D region VLF reflection height for west-east and east-west propagation paths to Fiji

    Science.gov (United States)

    Chand, Atishnal Elvin; Kumar, Sushil

    2017-08-01

    Very low frequency (VLF) signals from navigational transmitters propagate through the Earth-ionosphere waveguide formed by the Earth and the lower conducting ionosphere and show the pronounced minima during solar terminator transition between transmitter and receiver. Pronounced amplitude minima observed on 19.8 kHz (NWC transmitter) and 24.8 kHz (NLK transmitter) signals recorded at Suva (18.149°S, 178.446°E), Fiji, during 2013-2014, have been used to estimate the VLF modal interference distance (DMS) and nighttime D region VLF reflection height (hN). The NWC transmitter signal propagates mostly in west-east direction, and the NLK transmitter follows a transequatorial path propagating significantly in the east-west direction. The values of DMS calculated using midpath terminator speed are 2103 ± 172 km and 2507 ± 373 km for these paths having west-east and east-west components of VLF subionospheric propagation, respectively, which agree with previously published results and within 10% with theoretical values. We have also compared the DMS estimated using a terminator time method with that calculated using terminator speed for a particular day and found both the values to be consistent. The hN values were found to be maximum during winter of Southern Hemisphere for NWC signal and winter of Northern Hemisphere for NLK signal VLF propagation paths to Suva. The hN also shows significant day-to-day and seasonal variabilities with a maximum of about 10 km and 23 km for NWC and NLK signal propagation paths, respectively, which could be due to the atmospheric gravity waves associated with solar terminator transition, as well as meteorological factors such as strong lightnings.

  17. Wind waves spectra and other data collected using moored buoy in the Great Lakes, Gulf of Mexico, South Pacific and East/West coast of US from 01 June 2000 to 30 June 2000 (NODC Accession 0000217)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and other data were collected using moored buoys in the Great lakes, Gulf of Mexico, South Pacific and East/West coast of US from June 01, 2000 to...

  18. Subsidence history of the eastern Northern South Yellow Sea Basin, offshore Korea

    Science.gov (United States)

    Lee, Eunyoung

    2010-05-01

    The Northern South Yellow Sea Basin (NSYSB) is located between East China and West Korea, and is one of the basins in eastern Asia where rifting started in the late Mesozoic time, caused by large-scale interaction between the Pacific, Eurasian, and Indian plates. To analyze the detailed tectonic evolution of this basin, this study focuses on backstripping the subsidence history of four representative structures selected in the basin. This paper examines sag and half-graben structures in the Central Sub-basin as well as half-graben and graben structures in the SW Sub-basin. By sedimentary backstripping, the subsidence history of the eastern NSYSB can be grouped into a main subsidence phase in the Late Cretaceous - Oligocene and a secondary subsidence phase in the Middle Miocene - present. Both subsidence phases are separated by the uplift and erosion phase during Early Miocene times. The main subsidence phase itself consists of a rapid subsidence in the Late Cretaceous - Paleocene and a slow subsidence phases in the Eocene - Oligocene. These subsidence phases of this basin can be correlated to MSQ I, II and III identified in the SW Sub-basin with seismic stratigraphy, and can further be related to the convergence movement of Pacific-Eurasia and Indian-Eurasia plates.

  19. Regional cenozoic uplift and subsidence events in the southeastern North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Jordt, H.

    1995-12-31

    The Paleocene topography of the Fennoscandian Shield is indicated by outbuilding towards the Central Trough and the Ringkoebing-Fyn High. From Eocene until Pliocene time three events of relative vertical movements are indicated by changes in outbuilding directions and reflection termination patterns in the central North Sea. The firs event of uplift was in the Eocene and resulted in relative uplift of the Mid North Sea High and contemporary subsidence east of it, indicated by a change in outbuilding from north to west. A second event of uplift is indicated to the north of the study area at the Eocene-Oligocene boundary by renewed southward outbuilding in the Norwegian-Danish Basin. In Miocene until Early Pliocene time a relatively stationary, almost east-west striking, basin margin was probably located to the north along the Tornquist Zone as indicated by the continued outbuilding towards the Ringkoebing-Fyn High. A third event of relative uplift is indicated east of the study area by changes in the Pliocene outbuilding pattern. After the first event of uplift it appears that the deepest parts of the Eocene North Sea Basin was located more easterly than the deepest part are today. Apparently the two latest uplift events north and east of the study area were related to movements of, or along the Tornquist Zone or to regional uplift of the Fennoscandian Shield finally resulting in the present-day configuration of the North Sea. (au) 11 refs.

  20. Salt Marsh Response and Recovery to Coseismic Subsidence

    Science.gov (United States)

    Aranda, A. N.; Carlin, J. A.; Rhodes, B. P.; Kirby, M.; Leeper, R. J.; Smith, R. W.

    2016-12-01

    Salt marshes worldwide are under increasing stress from eustatic sea level rise. Along the tectonically active west coast of North America, some salt marshes are also vulnerable to abrupt increases in relative sea level rise (RSLR) resulting from coseismic subsidence. Elevation zonation of sub-environments within a marsh provides the opportunity to interpret the sedimentary record in marshes to infer past earthquakes, which may improve understanding of regional seismic hazards and ecosystem response to increases in sea level. Our study area is the Seal Beach Wetlands (SBW), an 3 km2 salt marsh straddling the seismically active Newport-Inglewood fault zone in southern California. A previous study of the SBW identified sedimentary evidence of three coseismic subsidence events. Here, our goals were to identify coseismic subsidence events preserved in SBW stratigraphy and to quantify marsh recovery following an earthquake to assess marsh resiliency to rapid RSLR. To do this, we focused on one core collected near the fringe of the SBW and applied a suite of sedimentary and geochemical analyses. Our results indicated that the SBW may preserve sedimentary evidence of four potential coseismic subsidence events. Events were distinguished in the stratigraphy by a sharp upper contact interpreted as an abrupt shift in marsh depositional sub-environments, from a vegetated marsh, to an intertidal mudflat or a subtidal environment. This stratigraphy suggests that the marsh rapidly subsided, preserving the evidence of the vegetated marsh as a peat deposit overlain by a low-organic mud or muddy-sand layer. A typical marsh accretion facies succession occurred above each earthquake event in the core, suggesting full marsh recovery. From the core data, we also observed that the net average rate of marsh recovery, i.e., marsh accretion, was consistent. Estimated recovery rates between 0.6 and 1.1 mm/yr were comparable to the overall accretion rate and regional late Holocene RSLR rate

  1. Analisis Penurunan Muka Tanah (Land Subsidence) Kota Semarang Menggunakan Citra Sentinel-1 Berdasarkan Metode Dinsar Pada Perangkat Lunak Snap

    OpenAIRE

    Fakhri Islam, Lukman Jundi; Prasetyo, Yudo; Sudarsono, Bambang

    2017-01-01

    Semarang city is the capital of Central Java province that is experiencing growth and rapid urban growth. However, based on its geological condition, Semarang City is formed by young alluvial deposits in which still allows the compaction that can cause land subsidence. In addition, groundwater extraction also contributed in the process of land subsidence in the Semarang City. To minimize its damage, land subsidence monitoring is required as a part of natural disaster mitigation. One of method...

  2. The spatiotempora variations rules of Songzao coal mining subsidence based on numerical simulation

    Science.gov (United States)

    Lu, J.; Li, Y.; Cheng, H.; Tang, Z.

    2015-11-01

    .0 m in 1999 was more than twice the area affected by subsidence in 2004. This in return, it was more than 7 times larger than the area affected by subsidence in 2009 of the one affected by subsidence in 2004. Extent of the area affected by the 2.5 m subsidence has also enlarged rapidly. This area has expanded by about 40 times in 2009 than its value in 2004. In addition, the area of subsidence of value 3.0 m has reached about 0.44 hm2 in 2009 from zero value. Finally, the fifth finding indicated that the overall extend of the mining subsidence was much more serious in southern than in northern side of the Songzao Mine. Moreover, it was indicated that the increasing rate of mining subsidence in the western side of the study area was as bigger as in the eastern side between 1999 and 2009. The spatiotemporal variations rules of songzao coal mining subsidence based on numerical simulation could provide reference for the subsequent subsidence prevention and land consolidation.

  3. The spatiotempora variations rules of Songzao coal mining subsidence based on numerical simulation

    Directory of Open Access Journals (Sweden)

    J. Lu

    2015-11-01

    affected by the subsidence 2.0 m in 1999 was more than twice the area affected by subsidence in 2004. This in return, it was more than 7 times larger than the area affected by subsidence in 2009 of the one affected by subsidence in 2004. Extent of the area affected by the 2.5 m subsidence has also enlarged rapidly. This area has expanded by about 40 times in 2009 than its value in 2004. In addition, the area of subsidence of value 3.0 m has reached about 0.44 hm2 in 2009 from zero value. Finally, the fifth finding indicated that the overall extend of the mining subsidence was much more serious in southern than in northern side of the Songzao Mine. Moreover, it was indicated that the increasing rate of mining subsidence in the western side of the study area was as bigger as in the eastern side between 1999 and 2009. The spatiotemporal variations rules of songzao coal mining subsidence based on numerical simulation could provide reference for the subsequent subsidence prevention and land consolidation.

  4. Subsidence at the Weeks Island SPR Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, S.J.

    1999-01-01

    The elevation change data measured at the Weeks Island SPR site over the last 16+ years has been studied and analyzed. The subsidence rate is not constant with time and while the subsidence rate may have increased slightly during the past several years, recently the rate has increased more dramatically. The most recent increase comes at a time when the Strategic Petroleum Reserve (SPR) storage mine had been emptied of oil and was in the process of being refilled with brine. Damage to surface structures that has been observed during the past 12-18 months is attributed to the continued subsidence and dtierential subsidence across structures. The recent greater subsidence rates were unanticipated according to analysis results and will be used to aid further subsidence model development.

  5. September 2016 Bayou Choctaw Subsidence Report

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, Dylan Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, Anna C. Snider [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    Subsidence monitoring is a crucial component to understanding cavern integrity of salt storage caverns. This report looks at historical and current data at the Bayou Choctaw Strategic Petroleum Reserve Site. Data from the most recent land-based annual surveys, GPS, and tiltmeter indicate the subsidence rates across the site are approximately 0.0 ft./yr. Because of this, there is no evidence from the subsidence survey to suggest any of the DOE caverns have been structurally compromised.

  6. Gender inequality and the 'East-West' divide in contraception: An analysis at the individual, the couple, and the country level.

    Science.gov (United States)

    Dereuddre, Rozemarijn; Van de Velde, Sarah; Bracke, Piet

    2016-07-01

    Despite generally low fertility rates in Europe, contraceptive behavior varies to a substantial extent. The dichotomy between Western, and Central and Eastern European countries is particularly relevant. Whereas the former are characterized by the widespread use of modern contraception, the latter show a high prevalence of traditional methods to control fertility. The current study aims to examine whether these differences can be attributed to differences in women's individual status, and in gender inequality at the couple and the country level. We combine data from the Generations and Gender Survey (2004-2011) and the Demographic Health Survey (2005-2009), covering seventeen European countries, to perform multinomial multilevel analyses. The results confirm that higher educated and employed women, and women who have an equal occupational status relative to their partner are more likely to use modern reversible contraception instead of no, traditional, or permanent methods. Absolute and relative employment are also positively related to using female instead of male methods. Furthermore, it is shown that higher levels of country-level gender equality are associated with a higher likelihood of using modern reversible and female methods, but not sterilization. Particularly country levels of gender equality are linked to the East-West divide in type of contraceptive method used. Our findings underscore that women's higher status is closely related to their use of effective, female contraception. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. A comparison of radio data and model calculations of Jupiter's synchrotron radition 2. East-west asymmetry in the radiation belts as a functon of Jovian longitude

    Science.gov (United States)

    de Pater, Imke

    1981-05-01

    On the basis of comparison of radio data and model calculations of Jupiter's synchrotron radiaton the 'hot region' or east-west asymmetry in the planet's radiation belts is proposed to be due to the combined effect of an overabundance of electrons at jovicentric longitudes λJ~240°-360° and the existence of a dusk dawn directed electric field over the inner magnetosphere, generated by the wind system in the upper atmosphere. The model calculations were based upon the magnetic field configurations derived from the Pioneer data by Acuna and Ness [1976] (the O4 model) and Davis, Jones and Smith (quoted in Smith and Gulkis [1979]) (the P11 (3,2)A model), with an electron distribution derived in the first paper of this series [de Pater, this issue]. We would infer from the calculations that the O4 model gives a slightly better fit to the data; the relatively large number density at λJ~240°-360°, however, might indicate the presence of even higher order moments in the field.

  8. Conifer Recruitment in Trembling Aspen (Populus Tremuloides Michx. Stands along an East-West Gradient in the Boreal Mixedwoods of Canada

    Directory of Open Access Journals (Sweden)

    Pierre Nlungu-Kweta

    2014-11-01

    Full Text Available Ongoing climate change is likely to result in shifts in successional dynamics in boreal mixedwood stands. Using data from provincial forest inventory databases, we examined the occurrence and abundance of the regeneration of various coniferous species (white spruce, black spruce and balsam fir along an east-west Canadian gradient in aspen-dominated stands. The interpretation of the results was based on environmental conditions, including climate, natural fire regime and human impacts. We found that conifer regeneration was present in aspen stands along the entire gradient, despite differences in climatic conditions and fire regimes between the west (warmer and drier, with large recurrent fires and east (more humid with relatively long fire cycles. However, abundance and distribution varied from one conifer species to the next. The abundance of white spruce decreased towards the eastern end of the longitudinal gradient, while balsam fir and black spruce abundance decreased towards the west. Although abundance decreased, balsam fir and black spruce regeneration was still present in western Canada. This study shows that it is difficult to interpret the effects of climate change on conifer recruitment without accounting for the superimposed effects of human activities.

  9. Summer global atmospheric patterns enhanced the Mediterranean East-West differences on tree growth at rear-edge temperate deciduous forests

    Science.gov (United States)

    Dorado Liñán, Isabel; Zorita, Eduardo; Gea-Izquierdo, Guillermo; Martínez-Sancho, Elisabet; Levanic, Tom; Zlatanov, Tzvetan; Di Filippo, Alfredo; Zang, Christian; Gutiérrez, Emilia; Menzel, Annette

    2016-04-01

    Overlaid to a general decrease on European beech and Sessile oak tree growth over the recent decades in the Mediterranean Basin, tree-ring records from western populations display a stronger growth decrease than eastern populations. We investigate here to what extent this spatial pattern of tree growth can be explained by the impact of sustained atmospheric circulation patterns in summertime. We use Canonical Correlation Analysis, a statistical method that identifies the patterns of two multivariate variables that are optimally correlated. A generalized change in growth trends, turning from a general increase during the period 1950-1981 to a generalized decrease in growth observed during the last three decades can be attributed to increasing summer temperatures, which exerts a dominant and negative influence on tree growth across sites. However, summer precipitation has gained in importance coinciding with the intensification of the geographical differences in tree sensitivity across the Mediterranean Basin. This intensification of the geographical differences in tree- growth during the last three decades can be traced back to an intensification of the Summer North Atlantic Oscillation that imparts an east-west dipole in summer precipitation. Under persistent positive SNAO, western populations are expected to face harsher summer conditions than central and eastern rear-edge populations, due to stronger decrease of precipitation in the west Mediterranean Basin. This increase in xericity will likely be negative for temperate deciduous broadleaf species at the rear-edge of their distribution in the Mediterranean Basin.

  10. NOAA marine environmental buoy data from moored buoys from the US East/West coasts, South Pacific, Gulf of Mexico, and the Great Lakes of US and other locations from 2001-07-01 to 2001-07-31 (NODC Accession 0000587)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from the US East/West coasts, South Pacific, Gulf of Mexico, Great Lakes and other locations. Data were...

  11. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-06-01 to 2002-06-30 (NCEI Accession 0000771)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  12. East-west current components and temperature profile data collected using thermistor, mooring, current meter and casts from the Atlantic Ocean as part of the IDOE/POLYMODE (International Decade of Ocean Exploration / combination of USSR POLYGON project and US MODE) from 16 December 1975 to 01 November 1977 (NODC Accession 8000270)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — East-west current components and temperature profile data were collected using thermistor, mooring, and current meter casts from December 16, 1975 to November 1,...

  13. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-07-01 to 2002-07-31 (NCEI Accession 0000773)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  14. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-04-01 to 2002-04-30 (NCEI Accession 0000726)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  15. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 01 November 2002 to 31 November 2002 (NCEI Accession 0000835)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  16. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 01 September 2002 to 31 September 2002 (NODC Accession 0000799)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  17. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-08-01 to 2002-08-31 (NCEI Accession 0000785)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  18. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-03-01 to 2002-03-31 (NCEI Accession 0000716)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  19. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-05-01 to 2002-05-31 (NODC Accession 0000752)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  20. GEOPHYSICAL INVESTIGATION OF GROUND SUBSIDENCE: A ...

    African Journals Online (AJOL)

    A synthesis of the results show that the ground subsidence is not precipitated by collapsed geologic feature such as sinkholes/ cavities but boiler load induced differential settlement arising from near surface incompetent (clayey) substratum, in the premises of the boilers. KEY WORDS: Ground subsidence, Vertical electrical ...

  1. 30 CFR 817.121 - Subsidence control.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Subsidence control. 817.121 Section 817.121... ACTIVITIES § 817.121 Subsidence control. (a) Measures to prevent or minimize damage. (1) The permittee must... control plan prepared pursuant to § 784.20 of this chapter. (c) Repair of damage—(1) Repair of damage to...

  2. DNA barcoding of bark and ambrosia beetles reveals excessive NUMTs and consistent east-west divergence across Palearctic forests.

    Science.gov (United States)

    Jordal, Bjarte H; Kambestad, Marius

    2014-01-01

    A comprehensive DNA barcoding library is very useful for rapid identification and detection of invasive pest species. We tested the performance of species identification in the economically most damaging group of wood-boring insects - the bark and ambrosia beetles - with particular focus on broad geographical sampling across the boreal Palearctic forests. Neighbour-joining and Bayesian analyses of cytochrome oxidase I (COI) sequences from 151 species in 40 genera revealed high congruence between morphology-based identification and sequence clusters. Inconsistencies with morphological identifications included the discovery of a likely cryptic Nearctic species of Dryocoetes autographus, the possible hybrid origin of shared mitochondrial haplotypes in Pityophthorus micrographus and P. pityographus, and a possible paraphyletic Xyleborinus saxeseni. The first record of Orthotomicus suturalis in North America was confirmed by DNA barcoding. The mitochondrial data also revealed consistent divergence across the Palearctic or Holarctic, confirmed in part by data from the large ribosomal subunit (28S). Some populations had considerable variation in the mitochondrial barcoding marker, but were invariant in the nuclear ribosomal marker. These findings must be viewed in light of the high number of nuclear insertions of mitochondrial DNA (NUMTs) detected in eight bark beetle species, suggesting the possible presence of additional cryptic NUMTs. The occurrence of paralogous COI copies, hybridization or cryptic speciation demands a stronger focus on data quality assessment in the construction of DNA barcoding databases. © 2013 John Wiley & Sons Ltd.

  3. Model test on partial expansion in stratified subsidence during foundation pit dewatering

    Science.gov (United States)

    Wang, Jianxiu; Deng, Yansheng; Ma, Ruiqiang; Liu, Xiaotian; Guo, Qingfeng; Liu, Shaoli; Shao, Yule; Wu, Linbo; Zhou, Jie; Yang, Tianliang; Wang, Hanmei; Huang, Xinlei

    2018-02-01

    Partial expansion was observed in stratified subsidence during foundation pit dewatering. However, the phenomenon was suspected to be an error because the compression of layers is known to occur when subsidence occurs. A slice of the subsidence cone induced by drawdown was selected as the prototype. Model tests were performed to investigate the phenomenon. The underlying confined aquifer was generated as a movable rigid plate with a hinge at one end. The overlying layers were simulated with remolded materials collected from a construction site. Model tests performed under the conceptual model indicated that partial expansion occurred in stratified settlements under coordination deformation and consolidation conditions. During foundation pit dewatering, rapid drawdown resulted in rapid subsidence in the dewatered confined aquifer. The rapidly subsiding confined aquifer top was the bottom deformation boundary of the overlying layers. Non-coordination deformation was observed at the top and bottom of the subsiding overlying layers. The subsidence of overlying layers was larger at the bottom than at the top. The layers expanded and became thicker. The phenomenon was verified using numerical simulation method based on finite difference method. Compared with numerical simulation results, the boundary effect of the physical tests was obvious in the observation point close to the movable endpoint. The tensile stress of the overlying soil layers induced by the underlying settlement of dewatered confined aquifer contributed to the expansion phenomenon. The partial expansion of overlying soil layers was defined as inversed rebound. The inversed rebound was induced by inversed coordination deformation. Compression was induced by the consolidation in the overlying soil layers because of drainage. Partial expansion occurred when the expansion exceeded the compression. Considering the inversed rebound, traditional layer-wise summation method for calculating subsidence should be

  4. Offshore gravimetric and subsidence monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Stenvold, Torkjell

    2008-06-15

    The introduction (Chapter 1) is complemented by the introductions given in Chapters 2 to 8. I am the first author of the articles in chapter 2 and 8. For the 5 articles in between I am a coauthor, and the sum of my contributions to those articles (as quantified by the respective first authors) represents about one article. Chapter 2 contains the article 'High-precision relative depth and subsidence mapping from seafloor water-pressure measurements' by Stenvold et al. (2006), published in the SPE Journal. It was submitted in March 2005, and a revised version that also contained results from the Troll 2005 survey (August) was submitted in February 2006. The method of obtaining high-precision relative depth measurements by the use of mobile pressure gauges is presented. Intra-survey and inter-survey depth repeatabilities from six surveys are presented, and the individual contributing errors are discussed and estimated. Average reservoir compressibility for the Troll field between 2002 and 2005 is obtained by matching measured subsidence with modeled subsidence. Chapter 3 contains the article 'A new seafloor gravimeter' by Sasagawa et al. (2003), published in Geophysics. It was submitted in September 2001, and a revised version was submitted in August 2002. This article describes the ROVDOG (Remotely operated Vehicledeployed Deep-Ocean Gravimeter) in detail. Gravity and pressure repeatability results from the two first Troll surveys in 1998 and 2000 are presented. Data reduction, instrumental and environmental corrections are also presented. Chapter 4 contains the article 'Precision of seafloor gravity and pressure measurements for reservoir monitoring' by Zumberge et al., and was submitted 29 February 2008 to Geophysics. This builds on the article by Sasagawa et al. (Chapter 3). Improvements and upto date intra- and inter survey repeatability results are presented. The emphasis is on gravity results since the relative depth measurements

  5. Quaternary subsidence of the Oahu Coastal Plain, Hawaiian Islands

    Science.gov (United States)

    Toomey, M.; Sandstrom, R. M.; Huppert, K.; Taylor, F. W.; Cronin, T. M.

    2016-12-01

    Inter-plate hotspots continue to test our understanding of how the Earth's lithosphere deforms in response to an applied load, in part, because many current models are based on short or discontinuous observational datasets. Here we reconstruct a record of relative sea level rise spanning nearly two million years using the strontium isotope stratigraphy (SIS) of shallow water carbonates (e.g. corals, mollusks) recovered from a >300 m long drill core through the coastal plain of Oahu. We then compare it to model-predicted subsidence histories for our site that incorporate displacements at Ewa Beach, Oahu, due to the flexural isostatic response of the lithosphere to loading of each volcano along the Hawaiian Ridge as well as its migration over the Hawaiian Swell. Preliminary results indicate Oahu experienced relatively rapid rates of subsidence ( 0.45 mm/yr) during the mid-Pleistocene—vertical displacements our model largely attributes to loading of West Molokai. An abrupt slowing of subsidence over the past million years may be driven by the relative eastward progression of volcanism, including construction of large shields on Maui and Hawaii. Shallowly buried, late Pleistocene aged corals, however, may suggest: (1) a more limited flexural response to this loading for southeastern Oahu than has been inferred from raised marine isotope stage (MIS) 11/13 dated, shallow-water, deposits found elsewhere on the island and/or (2) substantial dissolution of coastal plain carbonates between MIS 31 and 11.

  6. Fourth International Symposium on Land Subsidence

    Science.gov (United States)

    Johnson, A. I.

    Subsidence, or land-surface sinking, is a phenomenon that occurs in many parts of the world. Subsidence results from the heavy withdrawal of groundwater, geothermal fluids, oil, and gas; the extraction of coal, sulphur, and other solids through mining; the hydro-compaction of sediments; oxidation and shrinkage of organic deposits; the catastrophic development of sinkholes in karst terrain; and other phenomena. Over 150 areas of contemporary subsidence are known, some at rates of 10 m in countries such as Mexico, Japan, and the United States, for example. More areas of subsidence are likely to develop in the next few decades due to the accelerated exploitation of natural resources necessary to meet the demands of increasing population and industrial development in many countries.

  7. An Analysis Model for Water Cone Subsidence in Bottom Water Drive Reservoirs

    Science.gov (United States)

    Wang, Jianjun; Xu, Hui; Wu, Shucheng; Yang, Chao; Kong, lingxiao; Zeng, Baoquan; Xu, Haixia; Qu, Tailai

    2017-12-01

    Water coning in bottom water drive reservoirs, which will result in earlier water breakthrough, rapid increase in water cut and low recovery level, has drawn tremendous attention in petroleum engineering field. As one simple and effective method to inhibit bottom water coning, shut-in coning control is usually preferred in oilfield to control the water cone and furthermore to enhance economic performance. However, most of the water coning researchers just have been done on investigation of the coning behavior as it grows up, the reported studies for water cone subsidence are very scarce. The goal of this work is to present an analytical model for water cone subsidence to analyze the subsidence of water cone when the well shut in. Based on Dupuit critical oil production rate formula, an analytical model is developed to estimate the initial water cone shape at the point of critical drawdown. Then, with the initial water cone shape equation, we propose an analysis model for water cone subsidence in bottom water reservoir reservoirs. Model analysis and several sensitivity studies are conducted. This work presents accurate and fast analytical model to perform the water cone subsidence in bottom water drive reservoirs. To consider the recent interests in development of bottom drive reservoirs, our approach provides a promising technique for better understanding the subsidence of water cone.

  8. Subsidence due to geothermal fluid withdrawal

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, T. N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Univ. of California, Berkeley, CA (United States); Goyal, K. P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Univ. of California, Berkeley, CA (United States)

    1984-12-01

    Single-phase and two-phase geothermal reservoirs are currently being exploited for power production in Italy, Mexico, New Zealand, the United States, and elsewhere. Vertical ground displacements of up to 4.5 m and horizontal ground displacements of up to 0.5 m have been observed at Wairakei, New Zealand, that are clearly attributable to the resource exploitation. Similarly, vertical displacements of about 0.13 m have been recorded at The Geysers, California. No significant ground displacements that are attributable to large-scale fluid production have been observed at Larderello, Italy, and Cerro Prieto, Mexico. In this paper, observations show that subsidence due to geothermal fluid production is characterized by such features as an offset of the subsidence bowl from the main area of production, time-lag between production and subsidence, and nonlinear stress-strain relationships. Several plausible conceptual models, of varying degrees of sophistication, have been proposed to explain the observed features. At present, relatively more is known about the physical mechanisms that govern subsidence than the relevant thermal mechanisms. Finally, although attempts have been made to simulate observed geothermal subsidence, the modeling efforts have been seriously limited by a lack of relevant field data needed to sufficiently characterize the complex field system.

  9. Study on the risk and impacts of land subsidence in Jakarta

    Directory of Open Access Journals (Sweden)

    H. Z. Abidin

    2015-11-01

    Full Text Available Jakarta is the capital city of Indonesia located in the west-northern coast of Java island, within a deltaic plain and passes by 13 natural and artificial rivers. This megapolitan has a population of about 10.2 million people inhabiting an area of about 660 km2, with relatively rapid urban development. It has been reported for many years that several places in Jakarta are subsiding at different rates. The main causative factors of land subsidence in Jakarta are most probably excessive groundwater extraction, load of constructions (i.e., settlement of high compressibility soil, and natural consolidation of alluvial soil. Land subsidence in Jakarta has been studied using leveling surveys, GPS surveys, InSAR and Geometric-Historic techniques. The results obtained from leveling surveys, GPS surveys and InSAR technique over the period between 1974 and 2010 show that land subsidence in Jakarta has spatial and temporal variations with typical rates of about 3–10 cm year−1. Rapid urban development, relatively young alluvium soil, and relatively weak mitigation and adapatation initiatives, are risk increasing factors of land subsidence in Jakarta. The subsidence impacts can be seen already in the field in forms of cracking and damage of housing, buildings and infrastructure; wider expansion of (riverine and coastal flooding areas, malfunction of drainage system, changes in river canal and drain flow systems and increased inland sea water intrusion. These impacts can be categorized into infrastructural, environmental, economic and social impacts. The risk and impacts of land subsidence in Jakarta and their related aspects are discussed in this paper.

  10. November 2016 West Hackberry Subsidence Report

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, Dylan Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, Anna C. Snider [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    Subsidence monitoring is a critical component to understanding the cavern integrity of salt storage caverns. This report looks at historical and recent data from two of the three West Hackberry dome cavern operators. DOE SPR and LA Storage are coordinating subsidence surveys to create a comprehensive understanding of ground movement above the dome. Data from annual level and rod surveys, GPS, and tiltmeter data show the sites are experiencing typical ground movement. The highest subsidence rate is seen in the middle of the DOE SPR site at just under one inch per year with less ground movement around the edge of the site. A GPS and tiltmeter instrument in the northeast areas of the DOE SPR site has not seen any trend change since the devices were installed in 2013. Comparison between recent ground movement data and historical trends suggest that there is no reason to believe that any DOE SPR or LA Storage caverns have been structurally compromised.

  11. Robust processing of mining subsidence monitoring data

    Energy Technology Data Exchange (ETDEWEB)

    Wang Mingzhong; Huang Guogang [Pingdingshan Mining Bureau (China); Wang Yunjia; Guogangli [China Univ. of Mining and Technology, Xuzhou (China)

    1996-12-31

    Since China began to do research on mining subsidence in 1950s, more than one thousand lines have been observed. Yet, monitoring data sometimes contain quite a lot of outliers because of the limit of observation and geological mining conditions. In China, nowdays, the method of processing mining subsidence monitoring data is based on the principle of the least square method. It is possible to produce lower accuracy, less reliability, or even errors. For reason given above, the authors, according to Chinese actual situation, have done some research work on the robust processing of mining subsidence monitoring data in respect of how to get prediction parameters. The authors have derived related formulas, designed some computational programmes, done a great quantity of actual calculation and simulation, and achieved good results. (orig.)

  12. An east-west climate see-saw in the Mediterranean during the last 2.6 ka: evidence and mechanisms

    Science.gov (United States)

    Roberts, C.; Moreno-Caballud, A.; Valero-Garces, B. L.; Luterbacher, J.; Xoplaki, E.; Allcock, S. L.

    2012-12-01

    Global precipitation anomalies during the Common Era show a spatial coherency that appears to be about an order of magnitude lower (i.e. smaller) than for temperature changes, as some areas became wetter while others experienced drought (Seager et al., 2007, Quat. Sci. Rev. 26, 2322-36). The Mediterranean basin (10°W-40°E; 30°-45°N) is influenced by some of the main mechanisms acting upon the global climate system and its regional water resources are sensitive to hydro-climatic variations. Reconstructing the timing, intensity, and patterns of hydrological variability in the Mediterranean is important for testing spatial-temporal coherency in palaeo-precipitation, and for understanding underlying climate forcing mechanisms. The region offers a broad spectrum of documentary information and natural archives which allow high-resolution climate reconstructions (Luterbacher et al., 2012, In: Lionello et al. (eds) The Mediterranean Climate: from past to future. Elsevier, pp. 87-185). During the period of instrumental records, the NAO has strongly influenced inter-annual precipitation variations in the western Mediterranean, while parts of the eastern basin have shown an anti-phase relationship in precipitation and atmospheric pressure. A wide array of proxy-climate data from Iberia and Morocco indicate overall drier conditions during the Medieval Climate Anomaly (MCA) and a generally wetter climate in the Little Ice Age (LIA)(Moreno et al., 2012, Quat. Sci. Rev. 43, 16-32). This pattern is consistent with strong NAO forcing of western Mediterranean climate over the last 1.1 ka (Trouet et al., 2009; Science 324, 78-80). High-resolution palaeolimnological evidence from central Anatolia exhibit an opposite pattern, implying that an east-west climate see-saw operated in the Mediterranean basin during the LIA and MCA (Roberts et al., 2012; Glob. Planet. Change 84-85, 23-34). However, the strongest evidence for higher (lower) winter season precipitation during the MCA (LIA

  13. Mapping Ground Subsidence Phenomena in Ho Chi Minh City through the Radar Interferometry Technique Using ALOS PALSAR Data

    Directory of Open Access Journals (Sweden)

    Dinh Ho Tong Minh

    2015-07-01

    Full Text Available The rapidly developing urbanization since the last decade of the 20th century has led to extensive groundwater extraction, resulting in subsidence in Ho Chi Minh City, Vietnam. Recent advances in multi-temporal spaceborne SAR interferometry, especially with a persistent scatters interferometry (PSI approach, has made this a robust remote sensing technique for measuring large-scale ground subsidence with millimetric accuracy. This work has presented an advanced PSI analysis, to provide an unprecedented spatial extent and continuous temporal coverage of the subsidence in Ho Chi Minh City from 2006 to 2010. The study shows that subsidence is most severe in the Holocene silt loam areas along the Sai Gon River and in the southwest of the city. The groundwater extraction resulting from urbanization and urban growth is mainly responsible for the subsidence. Subsidence in turn leads to more flooding and water nuisance. The correlation between the reference leveling velocity and the estimated PSI result is R2 = 0.88, and the root mean square error is 4.3 (mm/year, confirming their good agreement. From 2006 to 2010, the estimation of the average subsidence rate is -8.0 mm/year, with the maximum value up to -70 mm/year. After four years, in regions along Sai Gon River and in the southwest of the city, the land has sunk up to -12 cm. If not addressed, subsidence leads to the increase of inundation, both in frequency and spatial extent. Finally, regarding climate change, the effects of subsidence should be considered as appreciably greater than those resulting from rising sea level. It is essential to consider these two factors, because the city is inhabited by more than 7.5 million people, where subsidence directly impacts urban structures and infrastructure.

  14. Evidence of regional subsidence and associated interior wetland loss induced by hydrocarbon production, Gulf Coast region, USA

    Science.gov (United States)

    Morton, Robert A.; Bernier, Julie C.; Barras, John A.

    2006-05-01

    Analysis of remote images, elevation surveys, stratigraphic cross-sections, and hydrocarbon production data demonstrates that extensive areas of wetland loss in the northern Gulf Coast region of the United States were associated with large-volume fluid production from mature petroleum fields. Interior wetland losses at many sites in coastal Louisiana and Texas are attributed largely to accelerated land subsidence and fault reactivation induced by decreased reservoir pressures as a result of rapid or prolonged extraction of gas, oil, and associated brines. Evidence that moderately-deep hydrocarbon production has induced land-surface subsidence and reactivated faults that intersect the surface include: (1) close temporal and spatial correlation of fluid production with surficial changes including rapid subsidence of wetland sediments near producing fields, (2) measurable offsets of shallow strata across the zones of wetland loss, (3) large reductions in subsurface pressures where subsidence rates are high, (4) coincidence of orientation and direction of displacement between surface fault traces and faults that bound the reservoirs, and (5) accelerated subsidence rates near producing fields compared to subsidence rates in surrounding areas or compared to geological rates of subsidence. Based on historical trends, subsidence rates in the Gulf Coast region near producing fields most likely will decrease in the future because most petroleum fields are nearly depleted. Alternatively, continued extraction of conventional energy resources as well as potential production of alternative energy resources (geopressured-geothermal fluids) in the Gulf Coast region could increase subsidence and land losses and also contribute to inundation of areas of higher elevation.

  15. Satellite Radar Measurements of Land Subsidence

    NARCIS (Netherlands)

    Halsema, D. van; Kooij, M.W.A. van der

    1996-01-01

    The potential of satelliteborne interferometric measurements for the mapping of slow land subsidence has been investigated. Two test sites, covered by the E,RS-1 satellite, were selected in the Netherlands: the provinces of Groningen and Zeeland. In situ measurements on the weather and the actual

  16. Land subsidence in the San Joaquin Valley, California, USA, 2007–2014

    Directory of Open Access Journals (Sweden)

    M. Sneed

    2015-11-01

    Full Text Available Rapid land subsidence was recently measured using multiple methods in two areas of the San Joaquin Valley (SJV: between Merced and Fresno (El Nido, and between Fresno and Bakersfield (Pixley. Recent land-use changes and diminished surface-water availability have led to increased groundwater pumping, groundwater-level declines, and land subsidence. Differential land subsidence has reduced the flow capacity of water-conveyance systems in these areas, exacerbating flood hazards and affecting the delivery of irrigation water. Vertical land-surface changes during 2007–2014 were determined by using Interferometric Synthetic Aperture Radar (InSAR, Continuous Global Positioning System (CGPS, and extensometer data. Results of the InSAR analysis indicate that about 7600 km2 subsided 50–540 mm during 2008–2010; CGPS and extensometer data indicate that these rates continued or accelerated through December 2014. The maximum InSAR-measured rate of 270 mm yr−1 occurred in the El Nido area, and is among the largest rates ever measured in the SJV. In the Pixley area, the maximum InSAR-measured rate during 2008–2010 was 90 mm yr−1. Groundwater was an important part of the water supply in both areas, and pumping increased when land use changed or when surface water was less available. This increased pumping caused groundwater-level declines to near or below historical lows during the drought periods 2007–2009 and 2012–present. Long-term groundwater-level and land-subsidence monitoring in the SJV is critical for understanding the interconnection of land use, groundwater levels, and subsidence, and evaluating management strategies that help mitigate subsidence hazards to infrastructure while optimizing water supplies.

  17. On correlation between urban development, land subsidence and flooding phenomena in Jakarta

    Science.gov (United States)

    Abidin, H. Z.; Andreas, H.; Gumilar, I.; Wibowo, I. R. R.

    2015-06-01

    Jakarta is the capital city of Indonesia with a population of about 10.2 million people, inhabiting an area of about 660 square-km. It is located within a deltaic plain and passes by 13 natural and artificial rivers. In the last three decades, urban development of Jakarta has grown very rapidly in the sectors of industry, trade, transportation, real estate and many others, which has caused several negative environmental impacts. In turns Jakarta is then prone toward a few natural hazards mainly land subsidence and flooding. In general, based on geodetic measurement methods (e.g. Leveling, GPS surveys, and InSAR), conducted since 1982 up to 2014, it is obtained that land subsidence in Jakarta exhibits spatial and temporal variations, with the typical rates of about 3 to 10 cm year-1. In general, the impacts of land subsidence in Jakarta can be seen in the forms of cracking of permanent constructions and roads, changes in river canal and drain flow systems, wider expansion of coastal and/or inland flooding areas, and malfunction of drainage system. Several areas along the coast of Jakarta already have experienced tidal flooding during high tide periods. These coastal flooding usually occurs in the areas with relatively large subsidence rates. Subsidence in the areas along the rivers which are flowing throughout Jakarta will also worsen the impacts of riverine flooding. The changes in river canal and drain flow systems and malfunction of drainage system due to land subsidence will also aggravate the flooding. Land subsidence will have direct and indirect affects with the flooding in Jakarta, both in coastal or inland areas.

  18. Land subsidence in the San Joaquin Valley, California, USA, 2007-14

    Science.gov (United States)

    Sneed, Michelle; Brandt, Justin

    2015-01-01

    Rapid land subsidence was recently measured using multiple methods in two areas of the San Joaquin Valley (SJV): between Merced and Fresno (El Nido), and between Fresno and Bakersfield (Pixley). Recent land-use changes and diminished surface-water availability have led to increased groundwater pumping, groundwater-level declines, and land subsidence. Differential land subsidence has reduced the flow capacity of water-conveyance systems in these areas, exacerbating flood hazards and affecting the delivery of irrigation water. Vertical land-surface changes during 2007–2014 were determined by using Interferometric Synthetic Aperture Radar (InSAR), Continuous Global Positioning System (CGPS), and extensometer data. Results of the InSAR analysis indicate that about 7600 km2 subsided 50–540 mm during 2008–2010; CGPS and extensometer data indicate that these rates continued or accelerated through December 2014. The maximum InSAR-measured rate of 270 mm yr−1 occurred in the El Nido area, and is among the largest rates ever measured in the SJV. In the Pixley area, the maximum InSAR-measured rate during 2008–2010 was 90 mm yr−1. Groundwater was an important part of the water supply in both areas, and pumping increased when land use changed or when surface water was less available. This increased pumping caused groundwater-level declines to near or below historical lows during the drought periods 2007–2009 and 2012–present. Long-term groundwater-level and land-subsidence monitoring in the SJV is critical for understanding the interconnection of land use, groundwater levels, and subsidence, and evaluating management strategies that help mitigate subsidence hazards to infrastructure while optimizing water supplies.

  19. Subsidence Contours for South Louisiana; UTM 15N NAD83; LRA (2005); [subsidence_contours

    Data.gov (United States)

    Louisiana Geographic Information Center — The GIS data shapefile represents average subsidence contour intervals (0.02 cm/year over 10,000 years) for Coastal LA derived from the following: Kulp, M.A., 2000,...

  20. Topography of the Overriding Plate During Progressive Subduction: A Dynamic Model to Explain Forearc Subsidence

    Science.gov (United States)

    Chen, Zhihao; Schellart, Wouter P.; Duarte, João. C.; Strak, Vincent

    2017-10-01

    Overriding plate topography provides constraints on subduction zone geodynamics. We investigate its evolution using fully dynamic laboratory models of subduction with techniques of stereoscopic photogrammetry and particle image velocimetry. Model results show that the topography is characterized by an area of forearc dynamic subsidence, with a magnitude scaling to 1.44-3.97 km in nature, and a local topographic high between the forearc subsided region and the trench. These topographic features rapidly develop during the slab free-sinking phase and gradually decrease during the steady state slab rollback phase. We propose that they result from the variation of the vertical component of the trench suction force along the subduction zone interface, which gradually increases with depth and results from the gradual slab steepening during the initial transient slab sinking phase. The downward mantle flow in the nose of the mantle wedge plays a minor role in driving forearc subsidence.

  1. InSAR Remote Sensing of Localized Surface Layer Subsidence in New Orleans, LA

    Science.gov (United States)

    An, K.; Jones, C. E.; Blom, R. G.; Kent, J. D.; Ivins, E. R.

    2015-12-01

    More than half of Louisiana's drinking water is dependent on groundwater, and extraction of these resources along with high oil and gas production has contributed to localized subsidence in many parts of New Orleans. This increases the vulnerability of levee failure during intense storms such as Hurricane Katrina in 2005, before which rapid subsidence had already been identified and contributed to the failing levees and catastrophic flooding. An interferogram containing airborne radar data from NASA's UAVSAR was combined with local geographic information systems (GIS) data for 2009-12 to help identify the sources of subsidence and mask out unrelated features such as surface water. We have observed the highest vertical velocity rates at the NASA Michoud Assembly Facility (high water use) and Norco (high oil/gas production). Many other notable features such as the: Bonnet-Carre Spillway, MRGO canal, levee lines along the Lower 9th Ward and power plants, are also showing concerning rates of subsidence. Even new housing loads, soil type differences, and buried beach sands seem to have modest correlations with patterns seen in UAVSAR. Current hurricane protection and coastal restoration efforts still have not incorporated late 20th century water level and geodetic data into their projections. Using SAR interferometry and local GIS datasets, areas of subsidence can be identified in a more efficient and economical manner, especially for emergency response.

  2. Mathematical Simulation of the Subsidence of Ravenna

    Science.gov (United States)

    Gambolati, Giuseppe; Ricceri, Giuseppe; Bertoni, Werter; Brighenti, Giovanni; Vuillermin, Enzo

    1991-11-01

    Land subsidence at Ravenna is the result of aquitard and reservoir compaction caused, respectively, by extensive groundwater withdrawals from the unconsolidated Quaternary basin and gas production from a number of pre-Quaternary pools scattered over the area. Water pumpage paralleled the postwar industrial development of Ravenna until the middle seventies when consumption was drastically curtailed owing to the economic crisis and the activation of a new aqueduct. Gas production started in 1952. The exploitation of several reservoirs is currently under way and the search for new fields is still in progress. Geodetic records indicate that the maximum cumulative subsidence over the period 1950-1986, including a natural geologic settlement of perhaps 2 mm/yr, has been 1.30 m in the industrial zone of Ravenna. In 1980 the municipality promoted a reconnaissance study with the primary aim of providing the information base needed to reconstruct the actual occurrence, understand correctly the physical behavior and produce the essential input data to a mathematical model which realistically relates the subsidence of the city to groundwater withdrawal and gas removal with an emphasis on their respective influences. The results from the three-dimensional numerical simulations, performed with the aid of mixed finite element, finite difference and integral models, show that the primary responsibility for the regional land sinking should be placed on the subsurface water overdraft which occurred until the middle 1970s. Gas withdrawal plays a role restricted to the area overlying each reservoir with a magnitude depending on the depth of burial, thickness of mineralized rocks and overall volumetric production. A major environmental impact may be expected where the gas subsidence bowl is intersected by the Adriatic coastline.

  3. Instruments for subsurface monitoring of geothermal subsidence

    Energy Technology Data Exchange (ETDEWEB)

    O' Rourke, J.E.; Ranson, B.B.

    1979-07-01

    The requirements for a subsurface geothermal subsidence instrument were reviewed. Available instruments for monitoring subsurface displacements, both vertical and horizontal, were studied and the most capable instruments identified. Techniques and materials for improving existing or developing new instruments were evaluated. Elements of sensor and signal technology with potential for high temperature monitoring of subsidence were identified. Drawing from these studies, methods to adapt production wells for monitoring were proposed and several new instrumentation systems were conceptually designed. Finally, four instrumentation systems were selected for future development. These systems are: triple sensor induction sensor probe (with casing collar markers); triple sensor gamma ray detector probe (with radioactive markers); triple sensor reed switch probe (with magnet markers); and triple sensor oscillator-type magnet detector probe (with magnet markers). All are designed for use in well casing incorporating slip couplings or bellows sections, although the gamma ray detector probe may also be used in unlined holes. These systems all measure vertical moement. Instruments to measure horizontal displacement due to geothermal subsidence were studied and the required instrument performance was judged to be beyond the state-of-the-art. Thus, no conceptual designs for instruments to monitor horizontal movement are included.

  4. Subsidence and associated shallow faulting hazard assessment in central Mexico using InSAR and GPS

    Science.gov (United States)

    Cabral-Cano, E.; Solano Rojas, D. E.; Oliver-Cabrera, T.; Salazar-Tlaczani, L.; Wdowinski, S.; DeMets, C.; Pacheco, J.

    2014-12-01

    While subsidence has affected Mexico City for over a century, other cities in central Mexico have been subjected to subsidence since the '80, as a result of their large urban expansion, population increase and aggressive groundwater extraction rates. The continuous subsidence results in severe damage to urban infrastructure and civil structures. Unfortunately the damage cost assessment and vulnerability are difficult to evaluate, because of the variable geographic extent and the continuous nature of the process, which have different characteristics than localized, short duration hazards, as earthquakes or flood events.We have monitored land subsidence in 17 cities in central Mexico using both InSAR and GPS observations. InSAR provides an unsurpassed synoptic view of the earth's dynamic surface. However, different satellite sensors and sometimes widely spaced data availability make it difficult to derive long-term time series, rapid changes or nonlinear variations of subsidence velocities. To alleviate this situation, higher temporal resolution subsidence observations of associated fault motion has been pursued using continuously operating GPS stations. We have developed a GPS network that covers 6 urban centers to detect short duration variations using different processing schemes that include both real-time solutions using RTNet as well as daily solution using Gipsy-Oasis.Cartographic products based on these techniques have been merged with other population, hydrology and meteorology data sets. This approach allows a better hazard assessment and provides information for other purposes, such as vulnerability for shallow faulting, land use zonations, and other decision elements for water resource management agencies. We will provide examples of these hazard assessments for several cities, including Mexico City, Aguascalientes, Morelia, Irapuato and Celaya and the challenges encountered to integrate these results with other data sets from federal and state

  5. Preliminary results of land subsidence monitoring project in Konya Closed Basin between 2006–2009 by means of GNSS observations

    Directory of Open Access Journals (Sweden)

    A. Ustun

    2010-06-01

    Full Text Available One of the potential dangers that might arise as a result of bringing excessive amounts of groundwater to the surface of the Earth is land subsidence. Such surface deformations – these velocities may vary from a few millimetres to a few metres per year – do the greatest damage to infrastructure facilities and buildings in residential units. Agricultural lands, in which excessive irrigation is performed, and densely populated cities are more likely to suffer from land subsidence. Konya Closed Basin (KCB, where a rapid groundwater withdrawal has been observed during the last 30–40 years, is faced with such a threat. In this study, the possibility of the occurrence of land subsidence, related to groundwater withdrawal for the KCB, is assessed and the geodetic studies conducted up to now, with the intention of identifying land subsidence, are introduced. The vertical displacements of between -12 and -52 mm/year have been detected through GNSS observations collected on the 6-point test network. The land subsidence phenomenon has been developing in the areas where the groundwater is extensively used for irrigation and daily life. The results support the findings derived from the historical leveling records and point out the need of an extended study based on both GNSS and InSAR techniques for spatial and temporal mapping of land subsidence in the KCB.

  6. Subsidence due to Excessive Groundwater Withdrawal in the San Joaquin Valley, California

    Science.gov (United States)

    Corbett, F.; Harter, T.; Sneed, M.

    2011-12-01

    Francis Corbett1, Thomas Harter1 and Michelle Sneed2 1Department of Land Air and Water Resources, University of California, Davis. 2U.S. Geological Survey Western Remote Sensing and Visualization Center, Sacramento. Abstract: Groundwater development within the Central Valley of California began approximately a century ago. Water was needed to supplement limited surface water supplies for the burgeoning population and agricultural industries, especially within the arid but fertile San Joaquin Valley. Groundwater levels have recovered only partially during wet years from drought-induced lows creating long-term groundwater storage overdraft. Surface water deliveries from Federal and State sources led to a partial alleviation of these pressure head declines from the late 1960s. However, in recent decades, surface water deliveries have declined owing to increasing environmental pressures, whilst water demands have remained steady. Today, a large portion of the San Joaquin Valley population, and especially agriculture, rely upon groundwater. Groundwater levels are again rapidly declining except in wet years. There is significant concern that subsidence due to groundwater withdrawal, first observed at a large scale in the middle 20th century, will resume as groundwater resources continue to be depleted. Previous subsidence has led to problems such as infrastructure damage and flooding. To provide a support tool for groundwater management on a naval air station in the southern San Joaquin Valley (Tulare Lake Basin), a one-dimensional MODFLOW subsidence model covering the period 1925 to 2010 was developed incorporating extensive reconstruction of historical subsidence and water level data from various sources. The stratigraphy used for model input was interpreted from geophysical logs and well completion reports. Gaining good quality data proved problematic, and often values needed to be estimated. In part, this was due to the historical lack of awareness/understanding of

  7. Geologic Subsidence in the Sacramento-San Joaquin Delta, California, and its Implications for Risk Assessment

    Science.gov (United States)

    Verosub, K. L.; Delusina, I.; Shlemon, R. J.

    2009-05-01

    twice as rapid as has generally been assumed. Second, the on-going geologic subsidence coupled with evidence for relative tectonic stability to the west of the Delta suggests that a generally north-south, active fault trends through the middle of the region. And finally, global glacial-interglacial cycles, imposed on the long-term geologic subsidence, likely led to the formation and burial of thick layers of older peat that could significantly affect the seismic response of the region.

  8. Recent Subsidence and Erosion at Diverse Wetland Sites in the Southeastern Mississippi Delta Plain

    Science.gov (United States)

    Morton, Robert A.; Bernier, Julie C.; Kelso, Kyle W.

    2009-01-01

    A prior study (U.S. Geological Survey Open-File Report 2005-1216) examined historical land- and water-area changes and estimated magnitudes of land subsidence and erosion at five wetland sites in the Terrebonne hydrologic basin of the Mississippi delta plain. The present study extends that work by analyzing interior wetland loss and relative magnitudes of subsidence and erosion at five additional wetland sites in the adjacent Barataria hydrologic basin. The Barataria basin sites were selected for their diverse physical settings and their recent (post-1978) conversion from marsh to open water. Historical aerial photography, datum-corrected marsh elevations and water depths, sediment cores, and radiocarbon dates were integrated to evaluate land-water changes in the Mississippi delta plain on both historical and geological time scales. The thickness of the organic-rich sediments (peat) and the elevation of the stratigraphic contact between peat and underlying mud were compared at marsh and open-water sites across areas of formerly continuous marsh to estimate magnitudes of recent delta-plain elevation loss caused by vertical erosion and subsidence of the wetlands. Results of these analyses indicate that erosion exceeded subsidence at most of the study areas, although both processes have contributed to historical wetland loss. Comparison of these results with prior studies indicates that subsidence largely caused rapid interior wetland loss in the Terrebonne basin before 1978, whereas erosional processes primarily caused more gradual interior wetland loss in the Barataria basin after 1978. Decadal variations in rates of relative sea-level rise at a National Ocean Service tide gage, elevation changes between repeat benchmark-leveling surveys, and GPS height monitoring at three National Geodetic Survey Continuously Operating Reference Stations indicate that subsidence rates since the early 1990s are substantially lower than those previously reported and are similar in

  9. Modeling Subsidence-Like Events on Cometary Nuclei

    Science.gov (United States)

    Rosenberg, Eric; Prialnik, Dina

    2017-10-01

    There is ample evidence, particularly from the Rosetta mission, that cometary nuclei have very low tensile strength. Consequently, morphological changes are expected to occur, caused by buildup of pressure due to gas release in the interior of the nucleus. Such changes have been observed on the surface of comet 67P/Churyumov-Gerasimenko, as reported for example by Groussin et al.(2015). A mechanism for explaining comet surface depressions has been recently proposed by Prialnik & Sierks (2017). Here we report on a numerical study, elaborating on this mechanism. Essentially, the model considers a cometary nucleus composed of a low-density mixture of ice and dust, assuming that the ice is amorphous and traps volatile gasses, such as CO and CO2. The model assumes that the tensile strength of the subsurface material is low and that the surface is covered by a thin crust of low permeability. As the comet evolves, the amorphous ice crystallizes, and the crystallization front recedes from the surface, releasing the trapped gasses, which accumulate beneath the surface, building up pressure. The gas pressure weakens the material strength, but sustains the gas-filled layer against hydrostatic pressure. Eventually, the gas will break its way through the outer crust in an outburst. The rapid pressure drop may cause the collapse of the gas depleted layer, as seen on the nucleus of 67P/Churyumov-Gerasimenko. This mechanism is similar to subsidence events in gas fields on earth.We have performed quasi-3D numerical simulations in an attempt to determine the extent of the area that would be affected by such a mechanism. The frequency of such subsidence events and the depth of the collapse are investigated as functions of solar angle and spin axis inclination. The necessary conditions for outburst-induced collapse are determined and confronted with observations.References:Groussin, O., Sierks, H., et al. 2015, A&A, 583, A35Prialnik, D. & Sierks, H., 2017, MNRAS, in press

  10. Progression and mitigation of land subsidence in China

    Science.gov (United States)

    Ye, Shujun; Xue, Yuqun; Wu, Jichun; Yan, Xuexin; Yu, Jun

    2016-05-01

    Land subsidence was first observed in Shanghai nearly a century ago, in 1921. Land subsidence attributed to groundwater extraction has been severe in China and is still occurring. Recent subsidence and associated earth fissures occurring since 2000 in three principal regions—the North China Plain, Fenwei Basin and Yangtze Delta—are introduced, and historical subsidence in these areas is briefly summarized. The subsidence-affected area in these regions with cumulative subsidence greater than or equal to 200 mm is more than 90,000 km2 and covers 22 provinces (cities), which include intensively developed and densely populated areas. Earth fissures accompanying the subsidence create significant geohazards; more than 1,000 earth fissures have been identified in the North China Plain, Fenwei Basin and Yangtze Delta. Effective land-subsidence-monitoring networks, that include continuous global positioning system (GPS) stations, repeat GPS and leveling surveys of geodetic benchmarks, InSAR, borehole extensometers, and groundwater observation wells, have been established in these three subsidence-affected areas. Mitigation measures and administrative means have been implemented in some areas, with good results in the Yangtze Delta area.

  11. Flooding hazards from sea extremes and subsidence

    DEFF Research Database (Denmark)

    Sørensen, Carlo; Vognsen, Karsten; Broge, Niels

    2015-01-01

    If we do not understand the effects of climate change and sea level rise (SLR) we cannot live in low-lying coastal areas in the future. Permanent inundation may become a prevalent issue but more often floods related to extreme events have the largest damage potential, and the management of flooding...... hazards needs to integrate the water loading from various sources. Furthermore, local subsidence must be accounted for in order to evaluate current and future flooding hazards and management options. We present the methodology (Figure) and preliminary results from the research project “Coastal Flooding...... Hazards due to Storm Surges and Subsidence” (2014-2017) with the objective to develop and test a practice oriented methodology for combining extreme water level statistics and land movement in coastal flooding hazard mapping and in climate change adaptation schemes in Denmark. From extreme value analysis...

  12. Effects of anthropogenic land-subsidence on river flood hazard: a case study in Ravenna, Italy

    Science.gov (United States)

    Carisi, Francesca; Domeneghetti, Alessio; Castellarin, Attilio

    2015-04-01

    quantify alterations to the flooding hazard due to large and rapid differential land-subsidence, shedding some light on whether to consider anthropogenic land-subsidence among the relevant human-induced drivers of flood-risk change.

  13. Effects of the Subsidized Students' Loan on University Enrolment in ...

    African Journals Online (AJOL)

    This paper examines the effect of the subsidized students' loan on university enrolment in Ghana between 1988-2008 using the autoregressive distributed lag (ARDL) framework. It was discovered that the subsidized student loan had positive and significant impact on university enrolment. Per capita gross domestic product ...

  14. Survey of land subsidence–case study: The land subsidence ...

    Indian Academy of Sciences (India)

    The artificial recharge is a technique of aquifer conservation for land subsidence. But in this article, the phenomenon of land subsidence and the resulting cracks and fissures at the study area are formed in recharge ponds. This is a new phenomenon and in this research the geometrical properties of the fissures of recharge ...

  15. Land subsidence associated with hydrocarbon production, Texas Gulf Coast

    Energy Technology Data Exchange (ETDEWEB)

    Kreitler, C.W.; White, W.A.; Akhter, M.S.

    1988-01-01

    Although ground-water withdrawal has been the predominant cause of land subsidence in the Texas Gulf Coast, localized subsidence and faulting have also resulted from hydrocarbon production. Subsidence was documented as early as the 1920s over the Goose Creek field. Since then, subsidence and/or faulting have been identified over the Saxet, South Houston, Chocolate Bayou, Hastings, Alco-Mag, Clinton, Mykawa, Blue Ridge, Webster, and Caplen oil fields. Oil-production-related subsidence over these fields generally creates few environmental or engineering problems. One exception is the subsidence and faulting over the Caplen oil field on Bolivar Peninsula, where more than 1,000 ac of saltwater marsh has been replaced by subaqueous flats. Subsidence may be occurring over other fields but has not been identified because of limited releveled benchmark data. An evaluation of drill-stem and bottom-hole pressure data for the Frio Formation in Texas indicates extensive depressurization presumably from hydrocarbon production. Nearly 12,000 measurements from a pressure data base of 17,000 measurements indicate some depressurization. Some of the Frio zones have pressure declines of more than 1,500 psi from original hydrostatic conditions. Subsidence and faulting may be associated with these fields in the Frio as well as other Tertiary formations where extensive hydrocarbon production and subsequent depressurization have occurred.

  16. The effective subsidence capacity concept: How to assure that subsidence in the Wadden Sea remains within defined limits?

    NARCIS (Netherlands)

    Waal, J.A. de; Roest,J.P.A.; Fokker, P.A.; Kroon, I.C.; Breunese, J.N.; Muntendam-Bos, A.G.; Oost, P.A.; Wirdum, G. van

    2012-01-01

    Subsidence caused by extraction of hydrocarbons and solution salt mining is a sensitive issue in the Netherlands. An extensive legal, technical and organisational framework is in place to ensure a high probability that such subsidence will stay within predefined limits. The key question is: how much

  17. Family Home Childcare Providers: A Comparison of Subsidized and Non-Subsidized Working Environments and Employee Issues

    Science.gov (United States)

    Shriner, Michael; Schlee, Bethanne M.; Mullis, Ronald L.; Cornille, Thomas A.; Mullis, Ann K.

    2008-01-01

    Federal and State Governments provide childcare subsidies for low-income working families. This study compares the encountered issues and working environments of family home providers of subsidized and non-subsidized childcare. Questionnaires were distributed throughout a southeastern state in the United States to 548 family home childcare…

  18. High-resolution InSAR constraints on flood-related subsidence and evaporite dissolution along the Dead Sea shores: Interplay between hydrology and rheology

    Science.gov (United States)

    Shviro, Maayan; Haviv, Itai; Baer, Gidon

    2017-09-01

    Sinkhole generation and land subsidence are commonly attributed to dissolution of subsurface layers by under-saturated groundwater and formation of cavities. Along the Dead Sea (DS) shorelines, this process also involves seasonal flash floods that are drained into the subsurface by existing and newly formed sinkholes. We quantify the contribution of flash-floods to salt dissolution and land subsidence using high-resolution interferometric synthetic aperture radar (InSAR). Subsidence rates during a 3-year period (2012-2015) were calculated from 57 COSMO SkyMed X-band interferograms bracketing major flood events and intra-flood periods in 21 sinkhole sites. The sites are located within channels and alluvial fans along the western shores of the Dead Sea, Israel. The observed subsidence reaches maximum rates of 2.5 mm/day, accumulating in specific sites to 500 mm/year. In most of the sinkhole sites a gradual increase in the annual subsidence rate is observed during the 3-year study period. Three different modes of response to floods were observed: (1) sites where floodwater is not directly channeled into sinkholes do not respond to floods; (2) sites adjacent to active channels with sinkholes are unaffected by specific floods but their subsidence rates increase gradually from early winter to mid-summer, and decay gradually until the following winter; and (3) sites in active channels with sinkholes are characterized by an abrupt increase in subsidence rates immediately after each flood (by a factor of up to 20) and by a subsequent quasi-exponential subsidence decay over periods of several months. In these latter sites, subsidence rates after each flood are temporally correlated with alternating groundwater levels in adjacent boreholes. The rapid rise in groundwater head following floods increases the hydraulic gradient of the under-saturated groundwater and hence also the groundwater discharge and the dissolution rate of the subsurface salt layer. A subsequent quasi

  19. Karst subsidence in South-Central Apulia, Southern Italy.

    Directory of Open Access Journals (Sweden)

    Delle Rose Marco

    2002-01-01

    Full Text Available Subsidence in the karst of Apulia (Southern Italy, one of the classical karst areas of Italy, is described in this paper. The carbonate rocks that make up the geological structure of the Apulia region are affected by subsidence, which is of different type and intensity depending upon geological, topographical, and hydrogeological conditions. In particular, we discriminate between inland subsidence and coastal subsidence. Inland subsidence is generally restricted to the presence of individual cavities, either empty or partly or totally filled with deposits produced by dissolution of soluble rocks underground. Locally, such subsidence can cause severe effects on anthropogenic structures above. The coastal plains of Apulia, particularly the southernmost part (Salento Peninsula, show interesting karst subsidence. Here the main feature is the development of compound sinks extending for several thousands of square metres, or the formation of individual, mostly circular, dolines along the coastline. Occurrence of one or the other of the above features seems to depend upon topographical conditions, and also upon their relationship with sea level oscillations.

  20. Subsidence from underground mining; environmental analysis and planning considerations

    Science.gov (United States)

    Lee, Fitzhugh T.; Abel, John F.

    1983-01-01

    Subsidence, a universal process that occurs in response to the voids created by extracting solids or liquids from beneath the Earth's surface, is controlled by many factors including mining methods, depth of extraction, thickness of deposit, and topography, as well as the in situ properties of the rock mass above the deposit. The impacts of subsidence are potentially severe in terms of damage to surface utility lines and structures, changes in surface-water and ground-water conditions, and effects on vegetation and animals. Although subsidence cannot be eliminated, it can be reduced or controlled in areas where deformation of the ground surface would produce dangerous or costly effects. Subsidence prediction is highly developed in Europe where there are comparatively uniform mining conditions and a long history of field measurements. Much of this mining has been carried out beneath crowded urban and industrial areas where accurate predictions have facilitated use of the surface and reduced undesirable impacts. Concerted efforts to understand subsidence processes in the United States are recent. Empirical methods of subsidence analysis and prediction based on local conditions seem better suited to the current state of knowledge of the varied geologic and topographic conditions in domestic coal mining regions than do theoretical/mathematical approaches. In order to develop broadly applicable subsidence prediction methods and models for the United States, more information is needed on magnitude and timing of ground movements and geologic properties.

  1. Analysis of spatial correlation between the phenomenon land subsidence and rob (tidal inundation) using sentinel-1 SAR, GPS and geological data in Semarang city-Indonesia

    Science.gov (United States)

    Prasetyo, Yudo; Fahrudin, Islam, Lukman Juhdi Fahri

    2017-07-01

    Semarang city is the capital of Central Java province that is experiencing growth and rapid urban growth. But as the development, Semarang indicated experiencing the phenomenon of land subsidence. This happens because the geological structure of the city of Semarang is formed of young alluvial deposits in which still allows the compaction can cause ground subsidence. In addition, groundwater extraction also contributed in the process of land subsidence in the city of Semarang. Other problems are more widespread and increasing phenomenon of tidal inundation (rob) in some areas that were previously normal. The phenomenon of land subsidence and inundation becomes one inhibiting the rate of development progress Semarang. This study aimed to explore the spatial correlation between the appearances of the widespread phenomenon of robs inundation to the level of land subsidence in the area of Semarang. Hypotheses are constructed in this study that the increasing value of land subsidence will provide significant implications for the spread of rob area in the city of Semarang. The method used is the analysis of the spatial correlation between the data processing results of sentinel-1 SAR using DINSAR method between the years 2015-2016, GPS observation data between the years 2015-2016 and geological data in the form of hydrogeology, underground and ground rock distribution also geology structure data. These data are processed simultaneously, including a compilation of the field validation method for determining the distribution of rob inundation and anticipates the new rob area. The results are analyzed in a spatial to see whether the emergence of a new robs area has a significant correlation to the increase in value of land subsidence in that area. In general, the land subsidence in Semarang based methods DINSAR and GPS ranges around 0.07 to 0.21 m/yr with standard deviation around 0.03 m. Expected results of this study can help Semarang city governments in anticipation of

  2. Shallow Faulting in Morelia, Mexico, Based on Seismic Tomography and Geodetically Detected Land Subsidence

    Science.gov (United States)

    Cabral-Cano, E.; Arciniega-Ceballos, A.; Vergara-Huerta, F.; Chaussard, E.; Wdowinski, S.; DeMets, C.; Salazar-Tlaczani, L.

    2013-12-01

    Subsidence has been a common occurrence in several cities in central Mexico for the past three decades. This process causes substantial damage to the urban infrastructure and housing in several cities and it is a major factor to be considered when planning urban development, land-use zoning and hazard mitigation strategies. Since the early 1980's the city of Morelia in Central Mexico has experienced subsidence associated with groundwater extraction in excess of natural recharge from rainfall. Previous works have focused on the detection and temporal evolution of the subsidence spatial distribution. The most recent InSAR analysis confirms the permanence of previously detected rapidly subsiding areas such as the Rio Grande Meander area and also defines 2 subsidence patches previously undetected in the newly developed suburban sectors west of Morelia at the Fraccionamiento Del Bosque along, south of Hwy. 15 and another patch located north of Morelia along Gabino Castañeda del Rio Ave. Because subsidence-induced, shallow faulting develops at high horizontal strain localization, newly developed a subsidence areas are particularly prone to faulting and fissuring. Shallow faulting increases groundwater vulnerability because it disrupts discharge hydraulic infrastructure and creates a direct path for transport of surface pollutants into the underlying aquifer. Other sectors in Morelia that have been experiencing subsidence for longer time have already developed well defined faults such as La Colina, Central Camionera, Torremolinos and La Paloma faults. Local construction codes in the vicinity of these faults define a very narrow swath along which housing construction is not allowed. In order to better characterize these fault systems and provide better criteria for future municipal construction codes we have surveyed the La Colina and Torremolinos fault systems in the western sector of Morelia using seismic tomographic techniques. Our results indicate that La Colina Fault

  3. Tectonic control of subsidence and southward displacement of southeast Louisiana with respect to stable North America

    Science.gov (United States)

    Dokka, Roy K.; Sella, Giovanni F.; Dixon, Timothy H.

    2006-12-01

    GPS data collected between 1995 and 2006 suggest that southeast Louisiana, including New Orleans and the larger Mississippi Delta, are both subsiding vertically and moving southward with respect to stable North America. Both motions are likely related due to their common tectonic setting. Subsidence in the New Orleans area occurs in part because it is located in the hanging wall of a large listric normal fault system that forms the northern boundary of a 7-10 km thick allochthon that is detached from stable North America. Southward motion of this allochthon relative to stable North America occurs at 2.2 +/- 0.6 mm/yr. The average subsidence rate for GPS sites located on the allochthon is 5.2 +/- 0.9 mm/yr relative to Earth's center of mass, or ~7 mm/yr relative to mean sea level. Motion of the allochthon is likely due to the gravity instability created by rapid Holocene sediment deposition in the delta following continental glacial retreat and is facilitated at depth by weak salt horizons. Because New Orleans and other communities of southeastern Louisiana lie atop this active allochthon, future motion of this body should be considered during rebuilding of the region following Hurricanes Katrina and Rita.

  4. Hurricane Katrina sediment slowed elevation loss in subsiding brackish marshes of the Mississippi River delta

    Science.gov (United States)

    McKee, K.L.; Cherry, J.A.

    2009-01-01

    Although hurricanes can damage or destroy coastal wetlands, they may play a beneficial role in reinvigorating marshes by delivering sediments that raise soil elevations and stimulate organic matter production. Hurricane Katrina altered elevation dynamics of two subsiding brackish marshes in the Mississippi River deltaic plain by adding 3 to 8 cm of sediment to the soil surface in August 2005. Soil elevations at both sites subsequently declined due to continued subsidence, but net elevation gain was still positive at both Pearl River (+1.7 cm) and Big Branch (+0.7 cm) marshes two years after the hurricane. At Big Branch where storm sediments had higher organic matter and water contents, post-storm elevation loss was more rapid due to initial compaction of the storm layer in combination with root-zone collapse. In contrast, elevation loss was slower at Pearl River where the storm deposit (high sand content) did not compact and the root zone did not collapse. Vegetation at both sites fully recovered within one year, and accumulation of root matter at Big Branch increased 10-fold from 2005 to 2006, suggesting that the hurricane stimulated belowground productivity. Results of this study imply that hurricane sediment may benefit subsiding marshes by slowing elevation loss. However, long-term effects of hurricane sediment on elevation dynamics will depend not only on the amount of sediment deposited, but on sediment texture and resistance to compaction as well as on changes in organic matter accumulation in the years following the hurricane.

  5. Evaluation of Subterranean Subsidence at Seal Beach National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this study was to determine the amount of subsurface subsidence at Naval Weapons Station Seal Beach (NWSSB) areas which include Seal Beach National...

  6. Adaptation and mitigation of land subsidence in Semarang

    Science.gov (United States)

    Andreas, Heri; Abidin, Hasanuddin Z.; Gumilar, Irwan; Sidiq, Teguh Purnama; Yuwono, Bambang

    2017-07-01

    Land subsidence is not a new phenomenon for Semarang. Some report said the subsidence in Semarang probably is occurring for more than 100 years. Based on the leveling surveys conducted by the Centre of Environmental Geology from 1999 to 2003 it was found that relatively large subsidence was detected around Semarang Harbor, Pondok Hasanuddin, Bandar Harjo and around Semarang Tawang Railway station, with the rates ranging from 1 to 17 cm/year. Results derived from GPS show that land subsidence in Semarang has spatial and temporal variations. In general, subsidence rates in Semarang have an average rate of about 6 to 7 cm/year, with maximum rates that can go up to 14-19 cm/year at certain locations. The impact of land subsidence in Semarang can be seen in several forms, such as the wider expansion of (coastal) flooding areas "rob", cracking of buildings and infrastructure, and increased inland sea water intrusion. It also badly influences the quality and amenity of the living environment and life (e.g. health and sanitation condition) in the affected areas. In the case of Semarang, adaptation and mitigation are considered very important. We have been done some investigations to this area by field observations (mapping the flooded area, mapping the infrastructure problems, interviewing people and seeing the adaptations, conduct GPS measurement to see deformation, etc.), gather information from Government, from digital media, etc., and we noticed people increased their house, and the local goverment elevated the road and the bridge, etc. regulary over less decade periode as part of adaptation. We also noticed the Central Goverment built the dyke and pumping station. Our conclusions said that the adaptation only made temporaly since significant land subsidence keep coming and worsening by the sea level which is keep rising. Another conclusion, so far we have seen lack of mitigation program, monitoring or even inevective mitigation in Semarang related to this subsidence

  7. Areas of ground subsidence due to geofluid withdrawal

    Energy Technology Data Exchange (ETDEWEB)

    Grimsrud, G.P.; Turner, B.L.; Frame, P.A.

    1978-08-01

    Detailed information is provided on four geothermal areas with histories of subsidence. These were selected on the basis of: physical relevance of subsidence areas to high priority US geothermal sites in terms of withdrawn geofluid type, reservoir depth, reservoir geology and rock characteristics, and overburden characteristics; and data completeness, quality, and availability. The four areas are: Chocolate Bayou, Raft River Valley, Wairakei, and the Geysers. (MHR)

  8. Satellite radar interferometry for monitoring subsidence induced by longwall mining activity using Radarsat-2, Sentinel-1 and ALOS-2 data

    Science.gov (United States)

    Ng, Alex Hay-Man; Ge, Linlin; Du, Zheyuan; Wang, Shuren; Ma, Chao

    2017-09-01

    This paper describes the simulation and real data analysis results from the recently launched SAR satellites, ALOS-2, Sentinel-1 and Radarsat-2 for the purpose of monitoring subsidence induced by longwall mining activity using satellite synthetic aperture radar interferometry (InSAR). Because of the enhancement of orbit control (pairs with shorter perpendicular baseline) from the new satellite SAR systems, the mine subsidence detection is now mainly constrained by the phase discontinuities due to large deformation and temporal decorrelation noise. This paper investigates the performance of the three satellite missions with different imaging modes for mapping longwall mine subsidence. The results show that the three satellites perform better than their predecessors. The simulation results show that the Sentinel-1A/B constellation is capable of mapping rapid mine subsidence, especially the Sentinel-1A/B constellation with stripmap (SM) mode. Unfortunately, the Sentinel-1A/B SM data are not available in most cases and hence real data analysis cannot be conducted in this study. Despite the Sentinel-1A/B SM data, the simulation and real data analysis suggest that ALOS-2 is best suited for mapping mine subsidence amongst the three missions. Although not investigated in this study, the X-band satellites TerraSAR-X and COSMO-SkyMed with short temporal baseline and high spatial resolution can be comparable with the performance of the Radarsat-2 and Sentinel-1 C-band data over the dry surface with sparse vegetation. The potential of the recently launched satellites (e.g. ALOS-2 and Sentinel-1A/B) for mapping longwall mine subsidence is expected to be better than the results of this study, if the data acquired from the ideal acquisition modes are available.

  9. Detecting and monitoring UCG subsidence with InSAR

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R J; Foxall, W; Yang, X

    2012-03-23

    The use of interferometric synthetic aperture radar (InSAR) to measure surface subsidence caused by Underground Coal Gasification (UCG) is tested. InSAR is a remote sensing technique that uses Synthetic Aperture Radar images to make spatial images of surface deformation and may be deployed from satellite or an airplane. With current commercial satellite data, the technique works best in areas with little vegetation or farming activity. UCG subsidence is generally caused by roof collapse, which adversely affects UCG operations due to gas loss and is therefore important to monitor. Previous studies have demonstrated the usefulness of InSAR in measuring surface subsidence related to coal mining and surface deformation caused by a coal mining roof collapse in Crandall Canyon, Utah is imaged as a proof-of-concept. InSAR data is collected and processed over three known UCG operations including two pilot plants (Majuba, South Africa and Wulanchabu, China) and an operational plant (Angren, Uzbekistan). A clear f eature showing approximately 7 cm of subsidence is observed in the UCG field in Angren. Subsidence is not observed in the other two areas, which produce from deeper coal seams and processed a smaller volume. The results show that in some cases, InSAR is a useful tool to image UCG related subsidence. Data from newer satellites and improved algorithms will improve effectiveness.

  10. Understanding Mississippi Delta Subsidence through Stratigraphic and Geotechnical Analysis of a Continuous Holocene Core at a Subsidence Superstation

    Science.gov (United States)

    Bridgeman, J.; Tornqvist, T. E.; Allison, M. A.; Jafari, N.

    2016-12-01

    Land-surface subsidence is a major contributor to recent Mississippi Delta land loss. Despite significant research efforts, the primary mechanisms and rates of delta subsidence remain the subject of debate. This has led to a broad range of subsidence rate estimates across the delta, making differentiating between subsidence mechanisms as well as coastal restoration efforts more challenging. New data from a continuous 39 m long, 12 cm diameter core taken during the installation of a subsidence monitoring superstation near the Mississippi River, SW of New Orleans, provides insight into the grain size, bulk density, geochronology, and geotechnical parameters of the entire Holocene succession. The core consists of three major sections. The top 11 m contain a modern marsh peat, followed by a silty clay loam with interspersed humic clays (14C age 1250 BP), a peat bed (14C age 2200-2950 BP), and silt loams. The middle section from 11 to 35 m is dominated by clay and silty clay, with a relative bulk density of 1.5 g/cc, which gradually becomes denser with depth and the bottom section (35 to 39 m) is marked by a high energy, shell-rich sand facies and a basal peat (14C age 9850 BP), which terminates at the core base in a densely packed, blue-gray silty clay loam, characteristic of the Pleistocene. The radiocarbon ages of marsh peat beds, combined with sea-level markers derived from basal peat elsewhere in the delta, enable the reconstruction of the local subsidence history at this site. Notably, the data shows a significant amount of vertical displacement from the dated organics in the top section of the core; 3.5 m in the humic clays and up to 5 m in the peat bed. The subsidence rates measured by the superstation apparatus, and the geotechnical measurements of core sediments, will aid in determining the dominant subsidence mechanisms (shallow vs. deep) in the region.

  11. A new soil mechanics approach to quantify and predict land subsidence by peat compression

    NARCIS (Netherlands)

    Koster, K.; Erkens, G.; Zwanenburg, C.

    2016-01-01

    Land subsidence threatens many coastal areas. Quantifying current and predicting future subsidence are essential to sustain the viability of these areas with respect to rising sea levels. Despite its scale and severity, methods to quantify subsidence are scarce. In peat-rich subsidence hot spots,

  12. Monitoring Subsidence in California with InSAR

    Science.gov (United States)

    Farr, T. G.; Jones, C. E.; Liu, Z.; Neff, K. L.; Gurrola, E. M.; Manipon, G.

    2016-12-01

    Subsidence caused by groundwater pumping in the rich agricultural area of California's Central Valley has been a problem for decades. Over the last few years, interferometric synthetic aperture radar (InSAR) observations from satellite and aircraft platforms have been used to produce maps of subsidence with cm accuracy. We are continuing work reported previously, using ESA's Sentinel-1 to extend our maps of subsidence in time and space, in order to eventually cover all of California. The amount of data to be processed has expanded exponentially in the course of our work and we are now transitioning to the use of the ARIA project at JPL to produce the time series. ARIA processing employs large Amazon cloud instances to process single or multiple frames each, scaling from one to many (20+) instances working in parallel to meet the demand (700 GB InSAR products within 3 hours). The data are stored in Amazon long-term storage and an http view of the products are available for users of the ARIA system to download the products. Higher resolution InSAR data were also acquired along the California Aqueduct by the NASA UAVSAR from 2013 - 2016. Using multiple scenes acquired by these systems, we are able to produce time series of subsidence at selected locations and transects showing how subsidence varies both spatially and temporally. The maps show that subsidence is continuing in areas with a history of subsidence and that the rates and areas affected have increased due to increased groundwater extraction during the extended western US drought. Our maps also identify and quantify new, localized areas of accelerated subsidence. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Geographic Information System (GIS) files are being furnished to DWR for further analysis of the 4 dimensional subsidence time-series maps. Part of this work was carried out at the

  13. East-West paths to unconventional computing.

    Science.gov (United States)

    Adamatzky, Andrew; Akl, Selim; Burgin, Mark; Calude, Cristian S; Costa, José Félix; Dehshibi, Mohammad Mahdi; Gunji, Yukio-Pegio; Konkoli, Zoran; MacLennan, Bruce; Marchal, Bruno; Margenstern, Maurice; Martínez, Genaro J; Mayne, Richard; Morita, Kenichi; Schumann, Andrew; Sergeyev, Yaroslav D; Sirakoulis, Georgios Ch; Stepney, Susan; Svozil, Karl; Zenil, Hector

    2017-08-14

    Unconventional computing is about breaking boundaries in thinking, acting and computing. Typical topics of this non-typical field include, but are not limited to physics of computation, non-classical logics, new complexity measures, novel hardware, mechanical, chemical and quantum computing. Unconventional computing encourages a new style of thinking while practical applications are obtained from uncovering and exploiting principles and mechanisms of information processing in and functional properties of, physical, chemical and living systems; in particular, efficient algorithms are developed, (almost) optimal architectures are designed and working prototypes of future computing devices are manufactured. This article includes idiosyncratic accounts of 'unconventional computing' scientists reflecting on their personal experiences, what attracted them to the field, their inspirations and discoveries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Mexico East-West Deflections (DMEX97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for Mexico, and North-Central is the DMEX97 model. The computation used about one million terrestrial and marine...

  15. Whither Unified Korea? East, West or Center?

    Science.gov (United States)

    2015-02-17

    national interests. 18 Bibliography Armacost, Michael H., and Kenneth B. Pyle. "Japan and the Unification of...Unification and After: The Challenge for U.S. Strategy. Indianapolis, IN: Hudson Institue, 2000. 19 Fingar, Thomas. "China’s Vision of World Order." In...Littlefield, 2014), 382. 31. Robert Dujarric, Korean Unification and After: The Challenge for U.S. Strategy, (Indianapolis, IN: Hudson

  16. Alaska East-West Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' surface deflection of the vertical grid for Alaska is the DEFLEC96 model. The computation used about 1.1 millionterrestrial and marine gravity data held...

  17. East-West Perspectives on Elder Learning

    Science.gov (United States)

    Tam, Maureen

    2012-01-01

    This paper describes and conceptualizes the meaning of lifelong learning from two cultural perspectives--East and West. It examines the different principles underpinning lifelong learning that explain why and how elders in the two cultures engage differently in continued learning. Finally, it discusses the cultural impact on elder learning by…

  18. Traces of warping subsided tectonic blocks on Miranda, Enceladus, Titan

    Science.gov (United States)

    Kochemasov, G.

    2007-08-01

    Icy satellites of the outer Solar system have very large range of sizes - from kilometers to thousands of kilometers. Bodies less than 400-500 km across have normally irregular shapes , often presenting simple Plato's polyhedrons woven by standing inertiagravity waves (see an accompanying abstract of Kochemasov). Larger bodies with enhanced gravity normally are rounded off and have globular shapes but far from ideal spheres. This is due to warping action of inertia-gravity waves of various wavelengths origin of which is related to body movements in elliptical keplerian orbits with periodically changing accelerations (alternating accelerations cause periodically changing forces acting upon a body what means oscillations of its spheres in form of standing warping waves). The fundamental wave 1 and its first overtone wave 2 produce ubiquitous tectonic dichotomy - two segmental structure and tectonic sectoring superimposed on this dichotomy. Two kinds of tectonic blocks (segments and sectors) are formed: uplifted (+) and subsided (-). Uplifting means increasing planetary radius of blocks, subsiding - decreasing radius (as a sequence subsiding blocks diminishing their surfaces must be warped, folded, wrinkled; uplifting blocks increasing their surfaces tend to be deeply cracked, fallen apart). To level changing angular momenta of blocks subsided areas are filled with denser material than uplifted ones (one of the best examples is Earth with its oceanic basins filled with dense basalts and uplifted continents built of less dense on average andesitic material). Icy satellites follow the same rule. Their warped surfaces show differing chemistries or structures of constructive materials. Uplifted blocks are normally built with light (by color and density) water ice. Subsided blocks - depressions, "seas', "lakes", coronas - by somewhat denser material differing in color from water ice (very sharply - Iapetus, moderately - Europa, slightly - many saturnian satellites). A very

  19. What’s the Score? Walkable Environments and Subsidized Households

    Directory of Open Access Journals (Sweden)

    Young-Jae Kim

    2016-04-01

    Full Text Available Neighborhood walkability can influence individual health, social interactions, and environmental quality, but the relationships between subsidized households and their walkable environment have not been sufficiently examined in previous empirical studies. Focusing on two types of subsidized housing developments (Low-Income Housing Tax Credit (LIHTC and Public Housing (PH in Austin, Texas, this study evaluates the neighborhood walkability of place-based subsidized households, utilizing objectively measured Walk Score and walking-related built environment data. We also used U.S. Census block group data to account for the socio-demographic covariates. Based on various data, we employed bivariate and multivariate analyses to specify the relationships between subsidized households and their neighborhood walkable environment. The results of our bivariate analyses show that LIHTC households tend to be located in car-dependent neighborhoods and have more undesirable walking-related built environment conditions compared with non-LIHTC neighborhoods. Our regression results also represent that LIHTC households are more likely to be exposed to neighborhoods with low Walk Score, less sidewalk coverage, and more highways and major roads, while there are no significant associations for PH households. These findings imply that more attention and effort toward reducing the inequitable distributions of walkable neighborhood features supporting rather than hindering healthy lifestyles must be provided to subsidized households.

  20. Monitoring ground subsidence in Jiaxing region using Envisat data

    Science.gov (United States)

    Li, Tao; Wu, Jicang; Zhang, Lina

    2011-10-01

    Jiaxing is 110 kilometers far away from Shanghai, the high speed railway and the planed maglev from Shanghai to Hangzhou cross Jiaxing city. It is very important to monitor ground subsidence in Jiaxing region for the safe running of the high speed railways. However, the traditional ground subsidence measurement methods, such as precise leveling and GPS, have a very low spatial resolution and are laborious. DInSAR technology is a new effective method for monitoring ground subsidence with high resolution and accuracy, but due to the influence of many kinds of noises, the interferograms cannot reveal ground deformation directly. In this work, small baseline subset (SBAS) method is applied to extract the ground subsidence information. SBAS can reduce the effects of topographic error and spatial decorrelation, and also increase the number of useable InSAR pairs. Totally 13 scenes of the Envisat SAR images covering Jiaxing region between 2008 and 2009 are chosen and processed. The results show that a funnel shaped ground subsidence appears at Pinghu city.

  1. Integration of subsidence, deformation, and groundwater-level measurements to characterize land subsidence in the San Joaquin Valley, California, USA

    Science.gov (United States)

    Sneed, M.; Solt, M.; Brandt, J.

    2012-12-01

    Extensive groundwater withdrawal from unconsolidated deposits in the San Joaquin Valley caused widespread aquifer-system compaction and resultant land subsidence that locally exceeded 8 meters (m) from 1926 to 1970. The importation of surface water in the early 1970s resulted in decreased pumping, recovery of water levels, and a reduced rate of compaction in some areas. However, reduced surface-water availability during droughts (1976-77, 1987-92, and 2007-09) caused increased pumping, water-level declines, and renewed compaction. Land subsidence resulting from this compaction has reduced freeboard and flow capacity of the Delta-Mendota Canal (DMC), the California Aqueduct, and other canals that deliver irrigation water and transport floodwater. The location and magnitude of vertical land-surface changes during 2006-11 in the northwestern and central San Joaquin Valley were determined using Interferometric Synthetic Aperture Radar (InSAR), Global Positioning System (GPS), and extensometer techniques. Results of the InSAR analysis indicate that a 3,200 square-kilometer area, including parts of the DMC, the San Joaquin River, and the Eastside Bypass, was affected by at least 20 millimeters (mm) of subsidence during 2008-10. Within that area, InSAR analysis also indicates a localized maximum subsidence of at least 540 mm. Furthermore, InSAR results for 2006-10 indicate that subsidence rates doubled around 2008. GPS surveys in 2008 and 2010 confirm the high rates of subsidence measured using InSAR; GPS surveys in late 2011 indicate that these high rates continued through the next year. A comparison of data from extensometers (anchored near the top of the Corcoran Clay) and a continuous GPS station near Mendota indicates that most of the aquifer-system compaction occurred below the top of the Corcoran Clay (CC). The lack of correlation between continuous GPS data near Los Banos, which show subsidence, and water levels from nearby wells screened above the CC, which show

  2. Fault control of subsidence, Houston-Galveston area, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Kreitler, C.W.

    1976-01-01

    Land subsidence increases the area in the Texas Coastal Zone which will be inundated by marine waters from hurricane flooding. Storm surge from a Carla-sized hurricane in 1976 would flood at least 25 square miles more land than Hurricane Carla did in 1961. Land subsidence in Harris and Galveston Couunties results primarily from ground-water production. The two-county area is interlaced with active surface faults with topographic escarpments and surface faults with no topographic escarpments that control drainage patterns and create subtle photographic linear patterns. Ground-water production activates these faults by differential compaction of the aquifer. The faults appear to be partial hydrologic barriers that compartmentalize land subsidence into several individual basins.

  3. Geometry and subsidence history of the Dead Sea basin: A case for fluid-induced mid-crustal shear zone?

    Science.gov (United States)

    ten Brink, Uri S.; Flores, C.H.

    2012-01-01

    Pull-apart basins are narrow zones of crustal extension bounded by strike-slip faults that can serve as analogs to the early stages of crustal rifting. We use seismic tomography, 2-D ray tracing, gravity modeling, and subsidence analysis to study crustal extension of the Dead Sea basin (DSB), a large and long-lived pull-apart basin along the Dead Sea transform (DST). The basin gradually shallows southward for 50 km from the only significant transverse normal fault. Stratigraphic relationships there indicate basin elongation with time. The basin is deepest (8-8.5 km) and widest (???15 km) under the Lisan about 40 km north of the transverse fault. Farther north, basin depth is ambiguous, but is 3 km deep immediately north of the lake. The underlying pre-basin sedimentary layer thickens gradually from 2 to 3 km under the southern edge of the DSB to 3-4 km under the northern end of the lake and 5-6 km farther north. Crystalline basement is ???11 km deep under the deepest part of the basin. The upper crust under the basin has lower P wave velocity than in the surrounding regions, which is interpreted to reflect elevated pore fluids there. Within data resolution, the lower crust below ???18 km and the Moho are not affected by basin development. The subsidence rate was several hundreds of m/m.y. since the development of the DST ???17 Ma, similar to other basins along the DST, but subsidence rate has accelerated by an order of magnitude during the Pleistocene, which allowed the accumulation of 4 km of sediment. We propose that the rapid subsidence and perhaps elongation of the DSB are due to the development of inter-connected mid-crustal ductile shear zones caused by alteration of feldspar to muscovite in the presence of pore fluids. This alteration resulted in a significant strength decrease and viscous creep. We propose a similar cause to the enigmatic rapid subsidence of the North Sea at the onset the North Atlantic mantle plume. Thus, we propose that aqueous fluid flux

  4. Coastal Flooding Hazards due to storm surges and subsidence

    DEFF Research Database (Denmark)

    Sørensen, Carlo; Knudsen, Per; Andersen, Ole B.

    Flooding hazard and risk mapping are major topics in low-lying coastal areas before even considering the adverse effects of sea level rise (SLR) due to climate change. While permanent inundation may be a prevalent issue, more often floods related to extreme events (storm surges) have the largest...... damage potential.Challenges are amplified in some areas due to subsidence from natural and/or anthropogenic causes. Subsidence of even a few mm/y may over time greatly impair the safety against flooding of coastal communities and must be accounted for in order to accomplish the economically most viable...

  5. Land Subsidence Affects Coastal Zone Vulnerability (Pengaruh Penurunan Tanah Terhadap Kerentanan Wilayah Pesisir

    Directory of Open Access Journals (Sweden)

    Pra Luber Agung Wibowo

    2015-09-01

    Full Text Available Vast development of urban cities in coastal area has caused rapid degradation of the environment. Coastal zone vulnerability is mainly influenced by sea level rise, land subsidence, storm surge, sediment transport, socio-economic and coastal management policies. Present study investigates the main factor influences coastal vulnerability of developing coastal urban city at north coast of Java. Two factors were observed in the study; firstly land subsidence was observed by geodetic and leveling methods. Secondly, tidal inundation was measured by field work and participatory mapping. Tidal inundation model was performed using spatial model. Physical vulnerability model was conducted by scoring and weighting. The results show that Average rate of land subsidence between 2003-2014 is -0,021 (0,0-0,091 m.yr-1. Tidal inundation in 2014 covering 1286.29 hectares, where the highest impact happened at brackish water pond (969.63 ha. Tidal inundation prediction on 2031 will inundate ​​1786.76 ha, which the largest tidal inundation is in the residential area (646.85 ha. Coastal zone vulnerability in the research areas predominantly was influenced by land subsidence, and classified in moderate vulnerable. Land subsidence happened due to most of research areas are consists of alluvial plains morphology units that are still in consolidation process. Land subsidence conditions strongly influence the extent of tidal inundation in the future. Keywords: land subsidence, tidal inundation, vulnerability, coastal zones   Pesatnya perkembangan kota di daerah pesisir menyebabkan degradasi lingkungan secara cepat. Kerentanan wilayah pesisir sangat dipengaruhi oleh kenaikan permukaan laut, penurunan tanah, gelombang badai, transport sedimen, kebijakan sosial ekonomi dan manajemen pesisir. Penelitian ini meneliti faktor utama yang mempengaruhi kerentanan pesisir pada pengembangan kota pesisir di pantai utara Jawa. Dua faktor yang diamati dalam penelitian ini; pertama

  6. Land subsidence and caprock dolines caused by subsurface gypsum dissolution and the effect of subsidence on the fluvial system in the Upper Tigris Basin (between Bismil Batman, Turkey)

    Science.gov (United States)

    Doğan, Uğur

    2005-11-01

    Karstification-based land subsidence was found in the Upper Tigris Basin with dimensions not seen anywhere else in Turkey. The area of land subsidence, where there are secondary and tertiary subsidence developments, reaches 140 km 2. Subsidence depth ranges between 40 and 70 m. The subsidence was formed as a result of subsurface gypsum dissolution in Lower Miocene formation. Although there are limestones together with gypsum and Eocene limestone below them in the area, a subsidence with such a large area is indicative of karstification in the gypsum. The stratigraphical cross-sections taken from the wells and the water analyses also verify this fact. The Lower Miocene gypsum, which shows confined aquifer features, was completely dissolved by the aggressive waters injected from the top and discharged through by Zellek Fault. This resulted in the development of subsidence and formation of caprock dolines on loosely textured Upper Miocene-Pliocene cover formations. The Tigris River runs through the subsidence area between Batman and Bismil. There are four terrace levels as T1 (40 m), T2 (30 m), T3 (10 m) and T4 (4-5 m) in the Tigris River valley. It was also found that there were some movements of the levels of the terraces in the valley by subsidence. The subsidence developed gradually throughout the Quaternary; however no terrace was formed purely because of subsidence.

  7. Land subsidence in major cities of Central Mexico: Interpreting InSAR-derived land subsidence mapping with hydrogeological data

    Science.gov (United States)

    Castellazzi, Pascal; Arroyo-Domínguez, Norma; Martel, Richard; Calderhead, Angus I.; Normand, Jonathan C. L.; Gárfias, Jaime; Rivera, Alfonso

    2016-05-01

    Significant structural damages to urban infrastructures caused by compaction of over-exploited aquifers are an important problem in Central Mexico. While the case of Mexico City has been well-documented, insight into land subsidence problems in other cities of Central Mexico is still limited. Among the cities concerned, we present and discuss the cases of five of them, located within the Trans-Mexican Volcanic Belt (TMVB): Toluca, Celaya, Aguascalientes, Morelia, and Queretaro. Applying the SBAS-InSAR method to C-Band RADARSAT-2 data, five high resolution ground motion time-series were produced to monitor the spatio-temporal variations of displacements and fracturing from 2012 to 2014. The study presents recent changes of land subsidence rates along with concordant geological and water data. It aims to provide suggestions to mitigate future damages to infrastructure and to assist in groundwater resources management. Aguascalientes, Celaya, Morelia and Queretaro (respectively in order of decreasing subsidence rates) are typical cases of fault-limited land subsidence of Central Mexico. It occurs as a result of groundwater over-exploitation in lacustrine and alluvial deposits covering highly variable bedrock topography, typical of horst-graben geological settings. Aguascalientes and Toluca show high rates of land subsidence (up to 10 cm/yr), while Celaya and Morelia show lower rates (from 2 to 5 cm/yr). Comparing these results with previous studies, it is inferred that the spatial patterns of land subsidence have changed in the city of Toluca. This change appears to be mainly controlled by the spatial heterogeneity of compressible sediments since no noticeable change occurred in groundwater extraction and related drawdown rates. While land subsidence of up to 8 cm/yr has been reported in the Queretaro Valley before 2011, rates inferior to 1 cm/yr are measured in 2013-2014. The subsidence has been almost entirely mitigated by major changes in the water management

  8. Detecting, mapping and monitoring of land subsidence in Jharia ...

    Indian Academy of Sciences (India)

    land subsidence are generally complex and spa- tially varied. This gives rise to spatially scattered, .... length L-band data, the data pairs with larger spa- tial and temporal baselines than C-band data could be used ...... data; In: Proceedings of Urban Remote Sensing Event,. Shanghai, China, 20–22 May 2009, 6p. Lokhande ...

  9. How large-scale subsidence affects stratocumulus transitions

    Directory of Open Access Journals (Sweden)

    J. J. van der Dussen

    2016-01-01

    Full Text Available Some climate modeling results suggest that the Hadley circulation might weaken in a future climate, causing a subsequent reduction in the large-scale subsidence velocity in the subtropics. In this study we analyze the cloud liquid water path (LWP budget from large-eddy simulation (LES results of three idealized stratocumulus transition cases, each with a different subsidence rate. As shown in previous studies a reduced subsidence is found to lead to a deeper stratocumulus-topped boundary layer, an enhanced cloud-top entrainment rate and a delay in the transition of stratocumulus clouds into shallow cumulus clouds during its equatorwards advection by the prevailing trade winds. The effect of a reduction of the subsidence rate can be summarized as follows. The initial deepening of the stratocumulus layer is partly counteracted by an enhanced absorption of solar radiation. After some hours the deepening of the boundary layer is accelerated by an enhancement of the entrainment rate. Because this is accompanied by a change in the cloud-base turbulent fluxes of moisture and heat, the net change in the LWP due to changes in the turbulent flux profiles is negligibly small.

  10. Subsidized buyer credits: Atypical results in strategic trade theory

    NARCIS (Netherlands)

    G.J. Stoelinga; J.M.A. Viaene (Jean-Marie); L.T. Visscher (Louis)

    1995-01-01

    textabstractUsing subsidized buyer credit as a policy tool, it is shown that the general result of strategic trade policy, namely that, by committing itself to an export subsidy, any government can favorably change the outcome of the Cournot oligopoly, does not necessarily hold.

  11. 46 CFR 381.8 - Subsidized vessel participation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Subsidized vessel participation. 381.8 Section 381.8 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MISCELLANEOUS CARGO PREFERENCE-U.S.-FLAG... directly pay or finance all or part of U.S.-flag ocean freight transportation costs for the carriage of dry...

  12. Subsidence characterization and modeling for engineered facilities in Arizona, USA

    Directory of Open Access Journals (Sweden)

    M. L. Rucker

    2015-11-01

    Full Text Available Several engineered facilities located on deep alluvial basins in southern Arizona, including flood retention structures (FRS and a coal ash disposal facility, have been impacted by up to as much as 1.8 m of differential land subsidence and associated earth fissuring. Compressible basin alluvium depths are as deep as about 300 m, and historic groundwater level declines due to pumping range from 60 to more than 100 m at these facilities. Addressing earth fissure-inducing ground strain has required alluvium modulus characterization to support finite element modeling. The authors have developed Percolation Theory-based methodologies to use effective stress and generalized geo-material types to estimate alluvium modulus as a function of alluvium lithology, depth and groundwater level. Alluvial material modulus behavior may be characterized as high modulus gravel-dominated, low modulus sand-dominated, or very low modulus fines-dominated (silts and clays alluvium. Applied at specific aquifer stress points, such as significant pumping wells, this parameter characterization and quantification facilitates subsidence magnitude modeling at its' sources. Modeled subsidence is then propagated over time across the basin from the source(s using a time delay exponential decay function similar to the soil mechanics consolidation coefficient, only applied laterally. This approach has expanded subsidence modeling capabilities on scales of engineered facilities of less than 2 to more than 15 km.

  13. IMPACT OF OIL ON THE MECHANICAL PROPERTIES OF SOIL SUBSIDENCE

    Directory of Open Access Journals (Sweden)

    Алексей Алексеевич Бурцев

    2016-08-01

    Full Text Available The paper studied the effect of oil content on the mechanical properties of soil subsidence - Ek modulus and compressibility factor m0, obtained in the laboratory with the help of artificial impregnation oil soil samples. A comparison of the above parameters with samples of the same soil in the natural and water-saturated conditions has been perfomed.

  14. Tectonics and subsidence evolution of the Sirt Basin, Libya

    NARCIS (Netherlands)

    Abadi, A.M.; Wees, J.D. van; Dijk, P.M. van; Cloetingh, S.A.P.L.

    2005-01-01

    Backstripping analysis of 225 wells located within the Sirt Basin (Fig. 1) provide new constraints on the Sirt Basin development. Four coherent tectonic phases from Late Jurassic to present. The presentation of contour maps of subsidence and crustal stretching allows to visualize spatial and

  15. Numerical analysis of surface subsidence in asymmetric parallel highway tunnels

    Directory of Open Access Journals (Sweden)

    Ratan Das

    2017-02-01

    Full Text Available Tunnelling related hazards are very common in the Himalayan terrain and a number of such instances have been reported. Several twin tunnels are being planned for transportation purposes which will require good understanding for prediction of tunnel deformation and surface settlement during the engineering life of the structure. The deformational behaviour, design of sequential excavation and support of any jointed rock mass are challenging during underground construction. We have raised several commonly assumed issues while performing stability analysis of underground opening at shallow depth. For this purpose, Kainchi-mod Nerchowck twin tunnels (Himachal Pradesh, India are taken for in-depth analysis of the stability of two asymmetric tunnels to address the influence of topography, twin tunnel dimension and geometry. The host rock encountered during excavation is composed mainly of moderately to highly jointed grey sandstone, maroon sandstone and siltstones. In contrast to equidimensional tunnels where the maximum subsidence is observed vertically above the centreline of the tunnel, the result from the present study shows shifting of the maximum subsidence away from the tunnel centreline. The maximum subsidence of 0.99 mm is observed at 4.54 m left to the escape tunnel centreline whereas the maximum subsidence of 3.14 mm is observed at 8.89 m right to the main tunnel centreline. This shifting clearly indicates the influence of undulating topography and in-equidimensional noncircular tunnel.

  16. The Opportunity Illusion: Subsidized Housing and Failing Schools in California

    Science.gov (United States)

    Pfeiffer, Deirdre

    2009-01-01

    Since the late 1980s, the Low-Income Housing Tax Credit (LIHTC) program has funded the bulk of subsidized development nationwide, enabling the construction of over 100,000 units targeted to lower income households in California alone (California Tax Credit Allocation Committee 2009c). Yet, by not encouraging the siting of projects in racially…

  17. Who Subsidizes Whom? An Analysis of Educational Costs and Revenues

    Science.gov (United States)

    Gillen, Andrew; Denhart, Matthew; Robe, Jonathan

    2011-01-01

    Conventional wisdom holds that colleges and universities heavily subsidize their students. This assertion seems correct, given that total spending per student is almost always in excess of per student tuition payments. However, as the authors show in this report, the conventional wisdom is wrong because it inappropriately compares only one revenue…

  18. Collaboration and Subsidized Early Care and Education Programs in Illinois

    Science.gov (United States)

    Spielberger, Julie; Zanoni, Wladimir; Barisik, Elizabeth

    2013-01-01

    As a result of policy changes following welfare reform in 1996 and the costs associated with providing high-quality early care and education for children of low-income working families, agency collaboration in the state of Illinois has become an increasingly salient feature of subsidized early care and education programs (SECE). The authors…

  19. Ground subsidence phenomena in Frakadona, West Thessaly, Greece

    Science.gov (United States)

    Tsangaratos, Paraskevas; Loupasakis, Constantinos; Ilia, Ioanna

    2017-09-01

    Ground subsidence is considered among the most frequent geological hazard that usually occurs as a consequence of a number of phenomena, namely: natural compaction of unconsolidated fine - grained deposits, groundwater over - exploitation, peat - oxidation and collapse of underground cavities. The main objective of the present study was to investigate the spatio - temporal patterns of ground deformation in the wider area of Farkadona Municipality in the north-eastern Trikala regional unit, Thessaly, Greece. A set of Synthetic Aperture Radar images, acquired in 1992-2003 by the European Space Agency satellites ERS1 and ERS2 and processed with the Persistent Scatterer Interferometry technique, along with geotechnical data from nearby exploratory boreholes, were used in order to explain the observed deformation. Increasing subsidence rates are observed at almost the entire area within the city complex of Farkadona, which is covered by loose Quaternary sediments of considerable depth. In most cases, the increased deformation rates have caused damages in the form of tensile cracks, mainly along the road network and adjacent buildings. The results of the performed analysis concluded that the geotechnical conditions of the loose deposits occupying the site and also the intensive exploitation of the aquifers are the two main causal factors of the land subsidence phenomena. Additionally, a clear correlation between the subsidence deformation rate and the thickness of the loose deposits has been detected. Besides the geological information, this study made clear that Persistent Scatterer Interferometry could be considered as a valuable tool and cost-efficient method for validating subsidence mechanisms and could serve as an alternative to ground-based measurements.

  20. A fusion model used in subsidence prediction in Taiwan

    Directory of Open Access Journals (Sweden)

    S.-J. Wang

    2015-11-01

    Full Text Available The Taiwan Water Resources Agency uses four techniques to monitor subsidence in Taiwan, namely data from leveling, global positioning system (GPS, multi-level compaction monitoring wells (MCMWs, and interferometry synthetic aperture radar (InSAR. Each data type has advantages and disadvantages and is suitable for different analysis tools. Only MCMW data provide compaction information at different depths in an aquifer system, thus they are adopted in this study. However, the cost of MCMW is high and the number of MCMW is relatively low. Leveling data are thus also adopted due to its high resolution and accuracy. MCMW data provide compaction information at different depths and the experimental data from the wells provide the physical properties. These data are suitable for a physical model. Leveling data have high monitoring density in spatial domain but lack in temporal domain due to the heavy field work. These data are suitable for a black- or grey-box model. Poroelastic theory, which is known to be more conscientious than Terzaghi's consolidation theory, is adopted in this study with the use of MCMW data. Grey theory, which is a widely used grey-box model, is adopted in this study with the use of leveling data. A fusion technique is developed to combine the subsidence predicted results from poroelastic and grey models to obtain a spatially and temporally connected two-dimensional subsidence distribution. The fusion model is successfully applied to subsidence predictions in Changhua, Yunlin, Tainan, and Kaohsiung of Taiwan and obtains good results. A good subsidence model can help the government to make the accurate strategies for land and groundwater resource management.

  1. Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam

    Science.gov (United States)

    Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwate...

  2. Study on the risk and impacts of land subsidence in Jakarta

    National Research Council Canada - National Science Library

    Abidin, H. Z; Andreas, H; Gumilar, I; Brinkman, J. J

    2015-01-01

    ... in Jakarta are subsiding at different rates. The main causative factors of land subsidence in Jakarta are most probably excessive groundwater extraction, load of constructions (i.e., settlement of high...

  3. Physical experiments of land subsidence within a maar crater: insights for porosity variations and fracture localization

    Directory of Open Access Journals (Sweden)

    M. Cerca

    2015-11-01

    Full Text Available We present the results of a series of physical models aiming to reproduce rapid subsidence (at least 25 m in 30 years observed in the sediments of a maar crater caused by extraction of groundwater in the interconnected adjacent aquifer. The model considered plausible variations in the geometry of the crater basement and the measured rate of groundwater extraction (1 m per year in the time interval from 2005 to 2011 in 15 wells located around the structure. The experiments were built within a rigid plastic bowl in which the sediments and rocks of the maar sequence were modeled using different materials: (a plasticine for the rigid country rock, (b gravel for the fractured country rock forming the diatreme fill and, (c water saturated hollow glass microbeads for the lacustrine sedimentary fill of the crater. Water table was maintained initially at the surface of the sediments and then was allowed to flow through a hole made at the base of the rigid bowl. Water extraction provoked a sequence of gentle deformation, fracturing, and faulting of the surface in all the experiments. Vertical as well as lateral displacements were observed in the surface of the experiments. We discuss the results of 2 representative models. The model results reproduced the main geometry of the ring faults affecting the crater sediments and helps to explain the diversity of structures observed in relation with the diatreme geometry. The surface of the models was monitored continuously with an optical interferometric technique called structured light projection. Images collected at nearly constant time intervals were analyzed using the ZEBRA software and the obtained interferometric pairs permitted to analyze the full field subsidence in the model (submilimetric vertical displacements. The experiments were conducted at a continuous flow rate extraction and show a also a linear subsidence rate. Comparison among the results of the physical models and the fault system

  4. The deformation behavior of soil mass in the subsidence region of Beijing, China

    Directory of Open Access Journals (Sweden)

    F. Tian

    2015-11-01

    Full Text Available Land subsidence induced by excessive groundwater withdrawal has been a major environmental and geological problem in the Beijing plain area. The monitoring network of land subsidence in Beijing has been established since 2002 and has covered the entire plain area by the end of 2008. Based on data from extensometers and groundwater observation wells, this paper establishes curves of variations over time for both soil mass deformation and water levels and the relationship between soil mass deformation and water level. In addition, an analysis of deformation behavior is carried out for soil mass with various lithologies at different depths depending on the corresponding water level. Finally, the deformation behavior of soil mass is generalized into five categories. The conclusions include: (i the current rate of deformation of the shallow soil mass is slowing, and most of the mid-deep and deep soil mass continue to compress at a more rapid speed; (ii the sand strata behaves elastically, while the clay soil mass at different depths is usually characterized by elastic-plastic and creep deformation, which can be considered as visco-elastoplastic.

  5. 24 CFR 982.521 - Rent to owner in subsidized project.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Rent to owner in subsidized project... URBAN DEVELOPMENT SECTION 8 TENANT BASED ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Rent and Housing Assistance Payment § 982.521 Rent to owner in subsidized project. (a) Applicability to subsidized project...

  6. Application of an adaptive neuro-fuzzy inference system to ground subsidence hazard mapping

    Science.gov (United States)

    Park, Inhye; Choi, Jaewon; Jin Lee, Moung; Lee, Saro

    2012-11-01

    We constructed hazard maps of ground subsidence around abandoned underground coal mines (AUCMs) in Samcheok City, Korea, using an adaptive neuro-fuzzy inference system (ANFIS) and a geographical information system (GIS). To evaluate the factors related to ground subsidence, a spatial database was constructed from topographic, geologic, mine tunnel, land use, and ground subsidence maps. An attribute database was also constructed from field investigations and reports on existing ground subsidence areas at the study site. Five major factors causing ground subsidence were extracted: (1) depth of drift; (2) distance from drift; (3) slope gradient; (4) geology; and (5) land use. The adaptive ANFIS model with different types of membership functions (MFs) was then applied for ground subsidence hazard mapping in the study area. Two ground subsidence hazard maps were prepared using the different MFs. Finally, the resulting ground subsidence hazard maps were validated using the ground subsidence test data which were not used for training the ANFIS. The validation results showed 95.12% accuracy using the generalized bell-shaped MF model and 94.94% accuracy using the Sigmoidal2 MF model. These accuracy results show that an ANFIS can be an effective tool in ground subsidence hazard mapping. Analysis of ground subsidence with the ANFIS model suggests that quantitative analysis of ground subsidence near AUCMs is possible.

  7. Advancing Coastal Climate Adaptation in Denmark by Land Subsidence Mapping using Sentinel-1 Satellite Imagery

    DEFF Research Database (Denmark)

    Sørensen, Carlo Sass; Broge, Niels H.; Mølgaard, Mads R.

    2016-01-01

    mapping using Sentinel-1 satellite imagery and leveling at two coastal locations in Denmark. Within both investigated areas current subsidence rates of 5-10 millimeters per year are found. This subsidence is related to the local geology, and challenges and potentials in bringing land subsidence mapping...

  8. 3D characterization of Holocene peat in the Netherlands : Implications for coastal-deltaic subsidence

    NARCIS (Netherlands)

    Koster, K.|info:eu-repo/dai/nl/374860890

    2017-01-01

    Human-induced subsidence threatens many coastal-deltaic plains, due to the amplifying effects it has on sea-level rise and flood risk. In the coastal-deltaic plain of the Netherlands, subsidence is primarily caused by the compression and oxidation of Holocene peat. The understanding of subsidence in

  9. Hierarchical stochastic model of terrain subsidence during tunnel excavation

    Science.gov (United States)

    Janda, Tomáš; Šejnoha, Jiří; Šejnoha, Michal

    2017-09-01

    In this contribution the Bayesian statistical method is applied to assess the expected probability distribution of the terrain subsidence in the course of tunnel excavation. The approach utilizes a number of simplifying assumptions regarding the system kinematics to arrive at a very simple model with just a few degrees of freedom. This deterministic model together with the intrinsic uncertainties of its parameters and measurement inaccuracies are used to formulate the stochastic model which defines a distribution of the predicted values of terrain subsidence. Assuming the measured data to be fixed, the stochastic model thus defines the likelihood function of the model parameters which is directly used for updating their prior distribution. This way the model parameters can be incrementally updated with each excavation step and the prediction of the model refined.

  10. Mining Land Subsidence Monitoring Using SENTINEL-1 SAR Data

    Science.gov (United States)

    Yuan, W.; Wang, Q.; Fan, J.; Li, H.

    2017-09-01

    In this paper, DInSAR technique was used to monitor land subsidence in mining area. The study area was selected in the coal mine area located in Yuanbaoshan District, Chifeng City, and Sentinel-1 data were used to carry out DInSAR techniqu. We analyzed the interferometric results by Sentinel-1 data from December 2015 to May 2016. Through the comparison of the results of DInSAR technique and the location of the mine on the optical images, it is shown that DInSAR technique can be used to effectively monitor the land subsidence caused by underground mining, and it is an effective tool for law enforcement of over-mining.

  11. Groundwater Regulation in the Houston-Galveston Region to Control Subsidence - Balancing Total Water Demand, Available Alternative Water Supplies, and Groundwater Withdrawal

    Science.gov (United States)

    Turco, M. J.

    2014-12-01

    In 1975, as a result of area residents and local governments becoming increasingly alarmed by the continued impact of subsidence on economic growth and quality of life in the region, the Harris-Galveston Coastal Subsidence District was created by the 64th Texas Legislature as an underground water conservation district. The primary mission of what is now the Harris-Galveston Subsidence District, is to provide for the regulation of the withdrawal of groundwater to control subsidence. Subsidence has been a concern in the Houston, TX area throughout most of recent history. Since 1906, over 10 feet of subsidence has occurred, with a broad area of 6 feet of subsidence throughout most of the Houston Area.Over its nearly forty years of existence, the District has developed substantial data sets providing the foundation for its regulatory plan. Annual water-level measurements, a network of deep extensometers, over 80 subsidence GPS monitors, and updated numerical and analytical models have been utilized. Periodically, the District utilizes U.S. Census data to predict the future magnitude and location of population and water demand. In 2013, all of these data sets were combined producing an updated regulatory plan outlining the timelines of conversion to alternative sources of water and defining the maximum percentage groundwater can contribute to a user's total water demand.The management of the groundwater resources within the District has involved significant coordination with regional ground and surface water suppliers; ongoing interaction with other state and local regulatory bodies; analysis of accurate and up to date predictions on water usage; the enforcement of real disincentives to those who rely too heavily on groundwater and a commitment to practicing and promoting water conservation.Water supplies in the region are projected to continue to be stressed in the future due to rapid population increases in the region. Future District efforts will be focused on

  12. Should bus commuting be subsidized for providing quality transport ...

    Indian Academy of Sciences (India)

    e-mail: geetamt@gmail.com. Abstract. Urban transport has ... (ii) Should bus prices be subsidized in order to provide a quality public transport system? (iii) How large is the modal shift in favour ..... been derived through a speed-flow relationship function, with a car free flow speed of 45 km/h, peak traffic speed of 24 km/h and ...

  13. Groundwater-flow and land-subsidence model of Antelope Valley, California

    Science.gov (United States)

    Siade, Adam J.; Nishikawa, Tracy; Rewis, Diane L.; Martin, Peter; Phillips, Steven P.

    2014-01-01

    Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley groundwater basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to 1972, groundwater provided more than 90 percent of the total water supply in the valley; since 1972, it has provided between 50 and 90 percent. Most groundwater pumping in the valley occurs in the Antelope Valley groundwater basin, which includes the rapidly growing cities of Lancaster and Palmdale. Groundwater-level declines of more than 270 feet in some parts of the groundwater basin have resulted in an increase in pumping lifts, reduced well efficiency, and land subsidence of more than 6 feet in some areas. Future urban growth and limits on the supply of imported water may increase reliance on groundwater.

  14. Flooding Hazard Maps of Different Land Uses in Subsidence Area

    Science.gov (United States)

    Lin, Yongjun; Chang, Hsiangkuan; Tan, Yihchi

    2017-04-01

    This study aims on flooding hazard maps of different land uses in the subsidence area of southern Taiwan. Those areas are low-lying due to subsidence resulting from over pumping ground water for aquaculture. As a result, the flooding due to storm surges and extreme rainfall are frequent in this area and are expected more frequently in the future. The main land uses there include: residence, fruit trees, and aquaculture. The hazard maps of the three land uses are investigated. The factors affecting hazards of different land uses are listed below. As for residence, flooding depth, duration of flooding, and rising rate of water surface level are factors affecting its degree of hazard. High flooding depth, long duration of flooding, and fast rising rate of water surface make residents harder to evacuate. As for fruit trees, flooding depth and duration of flooding affects its hazard most due to the root hypoxia. As for aquaculture, flooding depth affects its hazard most because the high flooding depth may cause the fish flush out the fishing ponds. An overland flow model is used for simulations of hydraulic parameters for factors such as flooding depth, rising rate of water surface level and duration of flooding. As above-mentioned factors, the hazard maps of different land uses can be made and high hazardous are can also be delineated in the subsidence areas.

  15. Sources of subsidence at the Salton Sea Geothermal Field

    Science.gov (United States)

    Barbour, Andrew J.; Evans, Eileen; Hickman, Stephen H.; Eneva, Mariana

    2016-01-01

    At the Salton Sea Geothermal Field (SSGF) in Southern California, surface deformation associated with geologic processes including sediment compaction, tectonic strain, and fault slip may be augmented by energy production activities. Separating the relative contributions from natural and anthropogenic sources is especially important at the SSGF, which sits at the apex of a complex tectonic transition zone connecting the southern San Andreas Fault with the Imperial Fault; but this has been a challenging task so far. Here we analyze vertical surface velocities obtained from the persistent scatterer InSAR method and find that two of the largest subsidence anomalies can be represented by a set of volumetric strain nuclei at depths comparable to geothermal well completion zones. In contrast, the rates needed to achieve an adequate fit to the magnitudes of subsidence are almost an order of magnitude greater than rates reported for annual changes in aggregate net-production volume, suggesting that the physical mechanism responsible for subsidence at the SSGF is a complicated interplay between natural and anthropogenic sources.

  16. Problem definition study of subsidence caused by geopressured geothermal resource development

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The environmental and socio-economic settings of four environmentally representative Gulf Coast geopressured geothermal fairways were inventoried. Subsidence predictions were prepared using feasible development scenarios for the four representative subsidence sites. Based on the results of the subsidence estimates, an assessment of the associated potential environmental and socioeconomic impacts was prepared. An inventory of mitigation measures was also compiled. Results of the subsidence estimates and impact assessments are presented, as well as conclusions as to what are the major uncertainties, problems, and issues concerning the future study of geopressured geothermal subsidence.

  17. Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.

    1982-06-01

    A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

  18. Measurement of Subsidence Across the Sacramento Delta: Applying InSAR to a Coherence-challenged Area

    Science.gov (United States)

    Jones, C. E.; Sharma, P.

    2014-12-01

    InSAR-based measurement of ground subsidence rates are notoriously challenging in agricultural areas because of rapid temporal decorrelation introduced by physical disturbance of the ground and water content changes. This can be mitigated by the use of longer wavelength instruments and time series techniques, but measurement remains a challenge particularly in areas where the deformation rates are low. Here we discuss techniques developed to work with low coherence data in a project to measure sub-island scale subsidence rates across the Sacramento-San Joaquin Delta using SBAS processing of L-band UAVSAR data collected between July 2009 and February 2014. Determination of rates in this area is particularly valuable because of the Delta's critical importance as a water resource for the State of California and as an enormously productive estuarine ecosystem. Subsidence across the region has left most of the man-made islands below mean sea level and the levees maintaining their integrity are subject to a wide range of threats, including failure during earthquakes on the nearby Hayward and San Andreas fault. This research was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  19. Integrating wireless sensor network for monitoring subsidence phenomena

    Science.gov (United States)

    Marturià, Jordi; Lopez, Ferran; Gigli, Giovanni; Intrieri, Emanuele; Mucchi, Lorenzo; Fornaciai, Alessandro

    2016-04-01

    An innovative wireless sensor network (WSN) for the 3D superficial monitoring of deformations (such as landslides and subsidence) is being developed in the frame of the Wi-GIM project (Wireless sensor network for Ground Instability Monitoring - LIFE12 ENV/IT/001033). The surface movement is detected acquiring the position (x, y and z) by integrating large bandwidth technology able to detect the 3D coordinates of the sensor with a sub-meter error, with continuous wave radar, which allows decreasing the error down to sub-cm. The Estació neighborhood in Sallent is located over the old potassium mine Enrique. This zone has been affected by a subsidence process over more than twenty years. The implementation of a wide network for ground auscultation has allowed monitoring the process of subsidence since 1997. This network consists of: i) a high-precision topographic leveling network to control the subsidence in surface; ii) a rod extensometers network to monitor subsurface deformation; iii) an automatic Leica TCA Total Station to monitor building movements; iv) an inclinometers network to measure the horizontal displacements on subsurface and v) a piezometer to measure the water level. Those networks were implemented within an alert system for an organized an efficient response of the civil protection authorities in case of an emergency. On 23rd December 2008, an acceleration of subsoil movements (of approx. 12-18 cm/year) provoked the activation of the emergency plan by the Catalan Civil Protection. This implied the preventive and scheduled evacuation of the neighbours (January 2009) located in the area with a higher risk of collapse: around 120 residents of 43 homes. As a consequence, the administration implemented a compensation plan for the evacuation of the whole neighbourhood residents and the demolition of 405 properties. In this work, the adaptation and integration process of Wi-GIM system with those conventional monitoring network are presented for its testing

  20. Dynamic Topography during Flat Subduction: Subsidence or Uplift?

    Science.gov (United States)

    Davila, F. M.; Lithgow-Bertelloni, C. R.

    2011-12-01

    Since the first studies on dynamic topography and basin evolution, low-dipping subduction has been related to intracontinental, long-wavelength and high-amplitude subsidence, whereas retreating to normal subduction systems to uplift. This was proposed to explain the Cretaceous-early Cenozoic topographic evolution of the western US. However, modern flat-slab and slab-retreating segments of South America do not record such a subsidence and uplift patterns. For example, the flat slab of Peru at ˜10°SL, related to the subduction of the Nazca Ridge, underlies an elevated promontory known as the Fitzcarrald Arch. The Argentine flat-slab at ˜31°SL associated to the subduction of the Juan Fernandez Ridge underlies a high-elevated intermontane system known as the Pampean broken foreland. Both upwarping features are younger than 7 Ma and contemporaneous with the arrival of flat subduction to these segments. In order to shed light into this controversy, we calculate dynamic topography along the Andean flat-slab segments using the Hager and O'Connell (1981) instantaneous flow formulation, an accurate reconstruction of the slab geometry along the central Andes and a density contrast between the flat slabs and the country mantle close to zero (△δ≈0) in order to simulate a buoyant oceanic lithosphere. We demonstrate that dynamic subsidence develops only at the leading edge of flat subduction, where the slabs plunge >30°, whereas the flatter slabs reproduce minor or no dynamic topography signals. These results agree with geological and geophysical proxies. Along the Argentine Plains, the account for a accumulated relief of ˜200 m, which might be considered as an "observed dynamic subsidence" signal (given that no tectonic activity has been recorded in this region since the Cretaceous to explain this surface topography). This gives a ˜0.03 mm/yr dynamic subsidence rate that are curiously similar to the exhumations estimated by low-temperature thermochronology along the

  1. Measuring Spatiotemporal Features of Land Subsidence, Groundwater Drawdown, and Compressible Layer Thickness in Beijing Plain, China

    Directory of Open Access Journals (Sweden)

    Yongyong Li

    2017-01-01

    Full Text Available Beijing is located on multiple alluvial-pluvial fans with thick Quaternary unconsolidated sediments. It has suffered serious groundwater drawdown and land subsidence due to groundwater exploitation. This study aimed to introduce geographical distribution measure methods into land subsidence research characterizing, geographically, land subsidence, groundwater drawdown, and compressible layer thickness. Therefore, we used gravity center analysis and standard deviational ellipse (SDE methods in GIS to statistically analyze their concentration tendency, principle orientation, dispersion trend, and distribution differences in 1995 (1999, 2007, 2009, 2011, and 2013. Results show that they were all concentrated in Chaoyang District of Urban Beijing. The concentration trend of land subsidence was consistent with that of groundwater drawdown. The principle orientation of land subsidence was SW–NE, which was more similar with that of the static spatial distribution of the compressible layer. The dispersion tendency of land subsidence got closer to that of the compressible layer with its increasing intensity. The spatial distribution difference between land subsidence and groundwater drawdown was about 0.2, and that between land subsidence and compressible layer thickness it decreased from 0.22 to 0.07, reflecting that the spatial distribution pattern of land subsidence was increasingly close to that of the compressible layer. Results of this study are useful for assessing the distribution of land subsidence development and managing groundwater resources.

  2. Coral ages and island subsidence, Hilo drill hole

    Science.gov (United States)

    Moore, J.G.; Ingram, B.L.; Ludwig, K. R.; Clague, D.A.

    1996-01-01

    A 25.8-m-thick sedimentary section containing coral fragments occurs directly below a surface lava flow (the ???1340 year old Panaewa lava flow) at the Hilo drill hole. Ten coral samples from this section dated by accelerator mass spectrometry (AMS) radiocarbon and five by thermal infrared multispectral scanner (TIMS) 230Th/U methods show good agreement. The calcareous unit is 9790 years old at the bottom and 1690 years old at the top and was deposited in a shallow lagoon behind an actively growing reef. This sedimentary unit is underlain by a 34-m-thick lava flow which in turn overlies a thin volcaniclastic silt with coral fragments that yield a single 14C date of 10,340 years. The age-depth relations of the dated samples can be compared with proposed eustatic sea level curves after allowance for island subsidence is taken. Island subsidence averages 2.2 mm/yr for the last 47 years based on measurements from a tide gage near the drill hole or 2.5-2.6 mm/yr for the last 500,000 years based on the ages and depths of a series of drowned coral reefs offshore from west Hawaii. The age-depth measurements of coral fragments are more consistent with eustatic sea levels as determined by coral dating at Barbados and Albrolhos Islands than those based on oxygen isotopic data from deep sea cores. The Panaewa lava flow entered a lagoon underlain by coral debris and covered the drill site with 30.9 m of lava of which 11 m was above sea level. This surface has now subsided to 4.2 m above sea level, but it demonstrates how a modern lava flow entering Hilo Bay would not only change the coastline but could extensively modify the offshore shelf.

  3. Subsidence history, crustal structure and evolution of the Nogal Rift, Northern Somalia

    Science.gov (United States)

    Ali, M. Y.; Watts, A. B.

    2013-12-01

    Seismic reflection profile, gravity anomaly, and biostratigraphic data from deep exploration wells have been used to determine the tectonic subsidence, structure and evolution of the Nogal basin, Northern Somalia, one of a number of ENE-WSW trending early Mesozoic rifts that formed prior to opening of the Gulf of Aden. Backstripping of biostratigraphic data at the Nogal-1 and Kali-1 wells provides new constraints on the age of rifting, and the amount of crustal and mantle extension. The tectonic subsidence and uplift history at the wells can be generally explained as a consequence of two, possibly three, major rifting events. The first event initiated in the Late Jurassic (~156 Ma) and lasted for ~10 Myr. We interpret the rift as a late stage event associated with the break-up of Gondwana and the separation of Africa and Madagascar. The second event initiated in the Late Cretaceous (~80 Ma) and lasted for ~20 Myr. This event probably correlates with a rapid increase in spreading rate on the ridges separating the African and Indian and African and Antarctica plates and a contemporaneous slowing down of Africa's plate motion. The backstripped tectonic subsidence data can be explained by a multi-rift extensional model with a stretching factor, β, in the range 1.17-1.38. The third and most recent event occurred in the Oligocene (~32 Ma) and lasted for ~10 Myr. This rift only developed at the centre of the basin close to Nogal-1 well, and is related to the opening of the Gulf of Aden. The amount of crustal thinning inferred at the Kali-1 well is consistent with the results of Process-Oriented Gravity and Flexure (POGM) modelling, assuming an elastic thickness of ~30 km. The thinning at the Nogal-1 well, however, is greater by ~ 7 km than predicted suggesting that the basin may be locally underplated by magmatic material. Irrespective, POGM suggests the transition between thick crust beneath Northern Somalia to thin crust beneath the Indian Ocean forms a ~500 km wide

  4. Aspects of sedimentary basin evolution assessed through tectonic subsidence analysis. Example: northern Gulf of Thailand

    Science.gov (United States)

    Pigott, John D.; Sattayarak, Nares

    Tectonic subsidence and subsidence rate analyses were conducted using a forward burial technique for the Cenozoic sediments of the northern Gulf of Thailand, a region presently bounded and intersected by major strike-slip fault systems. Basins represented by the seven wells studied are the Thon Buri, Hua Hin, Chumphon, Kra, and Pattani basins. The total observed subsidence was stratigraphically calibrated using well biostratigraphy and/or regional seismic stratigraphy. Tectonic subsidence was subsequently determined assuming local Airy isostasy by correcting decompacted sediments for sediment loading and variations in paleowater depths. Statistical comparison of the observed tectonic subsidence profile versus the theoretical thermal subsidence profile reveals zero-intercept times of incipient thermal-rifting and furthermore helps differentiate times of thermal subsidence from episodes of fault-controlled mechanical subsidence. Differences in tectonic subsidence, tectonic subsidence rates, and in the zero-intercept times of thermal rifting imply the Paleogene thermal associated rifting of the northern Gulf of Thailand was neither restricted spatially nor universally synchronous among the basins, but instead both spatially and time transgressive. Although coupled thermal-mechanical subsidence played a major role in the evolution for most of these basins, in some basins, e.g. the Thon Buri and northern Kra basins, subsidence was not thermally initiated. Instead, these basins experienced relatively slow-paced sediment loaded subsidence until a sudden fault-associated acceleration commenced in the Pliocene. Additional evidence for temporal and spatial changes in local strain is demonstrated by observed asynchronous episodes of "see-saw" subsidence-uplift of the basin floors. For example, while the northern Hua Hin Basin experienced Miocene-Pliocene alternations of subsidence and uplift, portions of the Pattani Basin to the southeast underwent periods of subsidence and

  5. Subsidence history, crustal structure, and evolution of the Somaliland-Yemen conjugate margin

    Science.gov (United States)

    Ali, M. Y.; Watts, A. B.

    2013-04-01

    We have used biostratigraphic data from deep exploration wells to determine the tectonic subsidence history of the Somaliland (northwestern Somalia)-Yemen conjugate margin, a poorly known margin in the central part of the Gulf of Aden. Bathymetry and magnetic anomaly data suggest the Gulf of Aden is a young feature that formed following the rifting apart and breakup of the African and Arabian plates ~32 Ma. Our tectonic subsidence data suggest, however, that the present-day Gulf of Aden developed on an earlier Mesozoic rift system. The oldest episode of rifting initiated at ~156 Ma and lasted for ~10 Ma and had a NW-SE trend. We interpret the rift as a late stage event associated with the breakup of Gondwana and the separation of Africa and Madagascar. At ~80 Ma, there is evidence of an intermediate rift event which correlates with a rapid increase in spreading rate on the ridges separating the African and Indian and African and Antarctica plates and a contemporaneous slowing down of Africa's plate motion. The combined effect of all three rifting events has been to thin the crust and upper mantle by up to a factor of 2. The amount of thinning deduced from the wells is in accord with the crustal structure inferred from available seismic refraction data and process-oriented gravity and flexure modeling. The margin is asymmetric with a steeper gradient in the Moho on the Yemen side than the Somaliland side. The main discrepancy is on the Yemen side where the gravity-derived Moho is 10 km deeper than the well-derived Moho. We attribute the discrepancy to the addition of material at the base of the crust since rifting, possibly magma sourced from the Afar plume.

  6. Risk evaluation of land subsidence and its application to metro safety operation in Shanghai

    Science.gov (United States)

    Liu, J.; Wang, H.; Yan, X.

    2015-11-01

    Based on sufficiently investigating characteristics and risk connotation of land subsidence, a risk evaluation index system for land subsidence disaster is established, which is combined with the sensitivity feature of the hazard bearing body to land subsidence. An appropriate evaluation method system is established by using an improved fuzzy analytic hierarchy process method. So risk evaluation is developed for providing theoretical basis and technical support for the regional management of land subsidence prevention and control. On this basis, as a case of Shanghai metro, firstly, the paper studies the identifying risk sources of the metro. According to metro linear characteristics, external indexes of representing subsidence risk are obtained. Studying the subsidence risk of the metro, relevant achievement has provided the technical basis for daily main monitoring, early warning and work arrangement.

  7. Land subsidence risk assessment and protection in mined-out regions

    Directory of Open Access Journals (Sweden)

    A. Zhao

    2015-11-01

    Full Text Available Land subsidence due to underground mining is an important hazard that causes large damages and threatens to social and economic activities. The China government has started a national project to estimate the risk of land subsidence in the main coal production provinces, such as Heilongjiang, Anhui and Shanxi Provinces. Herein, the investigation methods for land subsidence identification were reported, some types of land settlement are summarized, and some successful engineering measures to mitigate the subsidence are discussed. A Geographical Information System (GIS for land subsidence risk assessment is developed and is based on site investigations and numerrical simulation of the subsidence process. In this system, maps of mining intensity and risk ranks are developed.

  8. Land subsidence risk assessment and protection in mined-out regions

    Science.gov (United States)

    Zhao, A.; Tang, A.

    2015-11-01

    Land subsidence due to underground mining is an important hazard that causes large damages and threatens to social and economic activities. The China government has started a national project to estimate the risk of land subsidence in the main coal production provinces, such as Heilongjiang, Anhui and Shanxi Provinces. Herein, the investigation methods for land subsidence identification were reported, some types of land settlement are summarized, and some successful engineering measures to mitigate the subsidence are discussed. A Geographical Information System (GIS) for land subsidence risk assessment is developed and is based on site investigations and numerrical simulation of the subsidence process. In this system, maps of mining intensity and risk ranks are developed.

  9. Subsidence of titanium straight stems in combination with highly viscous bone cement.

    Science.gov (United States)

    Hendrich, Christian; Sauer, Ulf; Albrecht, Tobias; Rader, Christof P

    2005-04-01

    Varying results and a high rate of subsidence have been reported for the straight femoral stem (M.E. Muller) made of titanium alloy. We examined subsidence in 135 titanium-alloy straight stems implanted with high viscosity cement after 68.8+/-11.5 months using a digital high-precision method (EBRA-FCA). One revised implant showed a subsidence of 14.6 mm and another 2.5 mm over 5 years. A third implant without migration was found to be loose. The 122 implants without loosening showed a mean subsidence of 0.1+/-0.1 mm, and focal osteolysis was seen in two. Altogether, we found subsidence of the titanium stems very small. The small subsidence may be related to the use of high viscosity bone cement.

  10. Towards robust subsidence-based soil carbon emission factors for peat soils in south-east Asia, with special reference to oil palm plantations

    Directory of Open Access Journals (Sweden)

    J. Couwenberg

    2013-04-01

    Full Text Available Oil palm and Acacia pulpwood plantations are being established at a rapid rate on drained peatland in south-east Asia. Accurate measurements of associated carbon losses are still scarce, however, due mainly to difficulties of excluding autotrophic carbon fluxes from chamber-based flux measurements and uncertainties about the extent of waterborne losses. Here, we demonstrate a simple approach to determining total net carbon loss from subsidence records that is applicable to steady state conditions under continuous land use. We studied oil palm and Acacia plantations that had been drained for 5–19 years. Very similar subsidence rates and dry bulk density profiles were obtained, irrespective of crop type or age of the plantation, indicating that the peat profiles were in a steady state. These are conditions that allow for the deduction of net carbon loss by multiplying the rate of subsidence by the carbon density of the peat below the water table. With an average subsidence rate of 4.2 cm y-1 and a carbon density of 0.043 g cm-3, we arrive at a net carbon loss of ~18 t ha-1 y-1 (~66 t CO2-eq ha-1 y-1 for typical oil palm and Acacia plantations more than five years after drainage, without large differences between the plantation types. The proposed method enables calculation of regional or project-specific carbon loss rates to feed into mitigation schemes of the UN Framework Convention on Climate Change.

  11. UAVSAR and TerraSAR-X Based InSAR Detection of Localized Subsidence in the New Orleans Area

    Science.gov (United States)

    Blom, R. G.; An, K.; Jones, C. E.; Latini, D.

    2014-12-01

    Vulnerability of the US Gulf coast to inundation has received increased attention since hurricanes Katrina and Rita. Compounding effects of sea level rise, wetland loss, and regional and local subsidence makes flood protection a difficult challenge, and particularly for the New Orleans area. Key to flood protection is precise knowledge of elevations and elevation changes. Analysis of historical and continuing geodetic measurements show surprising complexity, including locations subsiding more rapidly than considered during planning of hurricane protection and coastal restoration projects. Combining traditional, precise geodetic data with interferometric synthetic aperture radar (InSAR) observations can provide geographically dense constraints on surface deformation. The Gulf Coast environment is challenging for InSAR techniques, especially with systems not designed for interferometry. We use two InSAR capable systems, the L- band (24 cm wavelength) airborne JPL/NASA UAVSAR, and the DLR/EADS Astrium spaceborne TerraSAR X-band (3 cm wavelength), and compare results. First, we are applying pair-wise InSAR to the longer wavelength UAVSAR data to detect localized elevation changes potentially impacting flood protection infrastructure from 2009 - 2014. We focus on areas on and near flood protection infrastructure to identify changes indicative of subsidence, structural deformation, and/or seepage. The Spaceborne TerraSAR X-band SAR system has relatively frequent observations, and dense persistent scatterers in urban areas, enabling measurement of very small displacements. We compare L-band UAVSAR results with permanent scatterer (PS-InSAR) and Short Baseline Subsets (SBAS) interferometric analyses of a stack composed by 28 TerraSAR X-band images acquired over the same period. Thus we can evaluate results from the different radar frequencies and analyses techniques. Preliminary results indicate subsidence features potentially of a variety of causes, including ground water

  12. Consideration of subsidence in land use planning policies and procedures in England

    Energy Technology Data Exchange (ETDEWEB)

    Brook, D. [U.K. Dept. of the Environment, London (United Kingdom)

    1996-12-31

    A widespread potential for subsidence requires consideration within a planning system which aims to control development in the public interest. A research strategy involving review at the national level of causes of subsidence followed by specific studies to develop techniques for use by planners provides the basis for planning guidance on the development of unstable land. This is now being taken forward with specific respect to subsidence to enable proper consideration in development plans and in considering applications for planning.

  13. The analysis of subsidence associated with geothermal development. Volume 1. Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Atherton, R.W.; Finnemore, E.J.; Gillam, M.L.

    1976-09-01

    This study evaluates the state of knowledge of subsidence associated with geothermal development, and provides preliminary methods to assess the potential of land subsidence for any specific geothermal site. The results of this study are presented in three volumes. Volume 1 is designed to serve as a concise reference, a handbook, for the evaluation of the potential for land subsidence from the development of geothermal resources.

  14. STUDY OF THE PIEZOMETRIC SURFACE AND HYDROCOMPACTION AT CONFINED AQUIFER CAUSED THE LAND SUBSIDENCE IN SEMARANG

    OpenAIRE

    Fahrudin Fahrudin; Najib Najib

    2012-01-01

    Semarang city has experienced of the land subsidence that be caused by intake groundwater in confined aquiferabundant. The land subsidence happened during range of time 20 years, it’s critical boundary so that result theenvironmental damage. Hence needed a study of cause of the land subsidence. This study aim to know theposition of piezometric surface and also explain the mechanism hydrogeology when happened the landsubsidence. The study of spreading aquifer has been done by the analysi...

  15. Assessing the Land Subsidence Governance in Ningbo City: By a Close Study of the Building Collapse at the Strictly Protected Land Subsidence Area

    Science.gov (United States)

    Yu, Xia

    2016-04-01

    Ningbo is a coastal city in East China, its land subsidence problem was noticed in the 1960s. However, scientific management was insufficient at that time, so with the fast city development from the 1980s, groundwater was used by a large amount of small factories, and tall buildings were built on the land. It was in 2008, scientists predicted that if without doing anything to prevent the land from subsiding, the city will be covered by the East Sea in 2030. From then on, the local government implied several policies, such as shut down most of the groundwater pumping wells, set up a new authority to enhance the cooperation among different administration departments, and also set up a land subsidence monitoring center for the city. Recently, it is declared that a Stereo regulatory system of land subsidence governance has been achieved. However, in 2012, a 23-years old building in the city center collapsed. According to the City Planning 2009, this building is located just in the strictly protected land subsidence area. The experts, however, think that land subsidence is not the main reason, since there are many illegal changes to the building during the past 23 years. The aim of my research is to assess the land subsidence governance in Ningbo city. I studied the collapsed building, how it was built, what has changed after building, how the environment changed in this area, and how this area became the strictly protected land subsidence area, and what kind of protections have been made. Actually, during the case study I discuss the land subsidence governance design of Ningbo, and to see what practices and lessons we can learn from this case.

  16. Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam

    Science.gov (United States)

    Minderhoud, P. S. J.; Erkens, G.; Pham, V. H.; Bui, V. T.; Erban, L.; Kooi, H.; Stouthamer, E.

    2017-06-01

    Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwater extraction is suggested as the main driver. As groundwater levels drop, subsidence is induced through aquifer compaction. Over the past 25 years, groundwater exploitation has increased dramatically, transforming the delta from an almost undisturbed hydrogeological state to a situation with increasing aquifer depletion. Yet the exact contribution of groundwater exploitation to subsidence in the Mekong delta has remained unknown. In this study we deployed a delta-wide modelling approach, comprising a 3D hydrogeological model with an integrated subsidence module. This provides a quantitative spatially-explicit assessment of groundwater extraction-induced subsidence for the entire Mekong delta since the start of widespread overexploitation of the groundwater reserves. We find that subsidence related to groundwater extraction has gradually increased in the past decades with highest sinking rates at present. During the past 25 years, the delta sank on average ˜18 cm as a consequence of groundwater withdrawal. Current average subsidence rates due to groundwater extraction in our best estimate model amount to 1.1 cm yr-1, with areas subsiding over 2.5 cm yr-1, outpacing global sea level rise almost by an order of magnitude. Given the increasing trends in groundwater demand in the delta, the current rates are likely to increase in the near future.

  17. Land subsidence and relative sea-level rise in the southern Chesapeake Bay region

    Science.gov (United States)

    Eggleston, Jack; Pope, Jason

    2013-01-01

    The southern Chesapeake Bay region is experiencing land subsidence and rising water levels due to global sea-level rise; land subsidence and rising water levels combine to cause relative sea-level rise. Land subsidence has been observed since the 1940s in the southern Chesapeake Bay region at rates of 1.1 to 4.8 millimeters per year (mm/yr), and subsidence continues today. This land subsidence helps explain why the region has the highest rates of sea-level rise on the Atlantic Coast of the United States. Data indicate that land subsidence has been responsible for more than half the relative sea-level rise measured in the region. Land subsidence increases the risk of flooding in low-lying areas, which in turn has important economic, environmental, and human health consequences for the heavily populated and ecologically important southern Chesapeake Bay region. The aquifer system in the region has been compacted by extensive groundwater pumping in the region at rates of 1.5- to 3.7-mm/yr; this compaction accounts for more than half of observed land subsidence in the region. Glacial isostatic adjustment, or the flexing of the Earth’s crust in response to glacier formation and melting, also likely contributes to land subsidence in the region.

  18. E-Area LLWF Vadose Zone Model: Probabilistic Model for Estimating Subsided-Area Infiltration Rates

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-12-12

    A probabilistic model employing a Monte Carlo sampling technique was developed in Python to generate statistical distributions of the upslope-intact-area to subsided-area ratio (AreaUAi/AreaSAi) for closure cap subsidence scenarios that differ in assumed percent subsidence and the total number of intact plus subsided compartments. The plan is to use this model as a component in the probabilistic system model for the E-Area Performance Assessment (PA), contributing uncertainty in infiltration estimates.

  19. Application of InSAR and Gravimetry for Land Subsidence Hazard Zoning in Aguascalientes, Mexico

    Directory of Open Access Journals (Sweden)

    Jesús Pacheco-Martínez

    2015-12-01

    Full Text Available In this work we present an application of InSAR and gravimetric surveys for risk management related to land subsidence and surface ground faulting generation. A subsidence velocity map derived from the 2007–2011 ALOS SAR imagery and a sediment thicknesses map obtained from the inversion of gravimetric data were integrated with a surface fault map to produce a subsidence hazard zoning in the city of Aguascalientes, Mexico. The resulting zoning is presented together with specific recommendations about geotechnical studies needed for further evaluation of surface faulting in these hazard zones. The derived zoning map consists in four zones including null hazard (stable terrain without subsidence, low hazard (areas prone to subsidence, medium hazard (zones with subsidence and high hazard (zones with surface faulting. InSAR results displayed subsidence LOS velocities up to 10 cm/year and two subsidence areas unknown before this study. Gravimetric results revealed that the thicker sediment sequence is located toward north of Aguascalientes City reaching up to 600 m in thickness, which correspond to a high subsidence LOS velocity zone (up to 6 cm/year.

  20. Imaging Land Subsidence Induced by Groundwater Extraction in Beijing (China Using Satellite Radar Interferometry

    Directory of Open Access Journals (Sweden)

    Mi Chen

    2016-06-01

    Full Text Available Beijing is one of the most water-stressed cities in the world. Due to over-exploitation of groundwater, the Beijing region has been suffering from land subsidence since 1935. In this study, the Small Baseline InSAR technique has been employed to process Envisat ASAR images acquired between 2003 and 2010 and TerraSAR-X stripmap images collected from 2010 to 2011 to investigate land subsidence in the Beijing region. The maximum subsidence is seen in the eastern part of Beijing with a rate greater than 100 mm/year. Comparisons between InSAR and GPS derived subsidence rates show an RMS difference of 2.94 mm/year with a mean of 2.41 ± 1.84 mm/year. In addition, a high correlation was observed between InSAR subsidence rate maps derived from two different datasets (i.e., Envisat and TerraSAR-X. These demonstrate once again that InSAR is a powerful tool for monitoring land subsidence. InSAR derived subsidence rate maps have allowed for a comprehensive spatio-temporal analysis to identify the main triggering factors of land subsidence. Some interesting relationships in terms of land subsidence were found with groundwater level, active faults, accumulated soft soil thickness and different aquifer types. Furthermore, a relationship with the distances to pumping wells was also recognized in this work.

  1. Superior coexistence: systematicALLY regulatING land subsidence BASED on set pair theory

    Science.gov (United States)

    Chen, Y.; Gong, S.-L.

    2015-11-01

    Anthropogenic land subsidence is an environmental side effect of exploring and using natural resources in the process of economic development. The key points of the system for controlling land subsidence include cooperation and superior coexistence while the economy develops, exploring and using natural resources, and geological environmental safety. Using the theory and method of set pair analysis (SPA), this article anatomises the factors, effects, and transformation of land subsidence. Based on the principle of superior coexistence, this paper promotes a technical approach to the system for controlling land subsidence, in order to improve the prevention and control of geological hazards.

  2. Monitoring ground subsidence in Shanghai maglev area using two kinds of SAR data

    Science.gov (United States)

    Wu, Jicang; Zhang, Lina; Chen, Jie; Li, Tao

    2012-11-01

    Shanghai maglev is a very fast traffic tool, so it is very strict with the stability of the roadbed. However, the ground subsidence is a problem in Shanghai because of the poor geological condition and human-induced factors. So it is necessary to monitor ground subsidence in the area along the Shanghai maglev precisely and frequently. Traditionally, a precise levelling method is used to survey along the track. It is expensive and time consuming, and can only get the ground subsidence information on sparse benchmarks. Recently, the small baseline differential SAR technique plays a valuable part in monitoring ground subsidence, which can extract ground subsidence information with high spatial resolution in a wide area. In this paper, L-band ALOS PALSAR data and C-band Envisat ASAR data are used to extract ground subsidence information using the SBAS method in the Shanghai maglev area. The results show that the general pattern of ground subsidence from InSAR processing of two differential bands of SAR images is similar. Both results show that there is no significant ground subsidence on the maglev line. Near the railway line, there are a few places with subsidence rates at about -20 mm/y or even more, such as Chuansha town, the junction of the maglev and Waihuan road.

  3. Superior coexistence: systematicALLY regulatING land subsidence BASED on set pair theory

    Directory of Open Access Journals (Sweden)

    Y. Chen

    2015-11-01

    Full Text Available Anthropogenic land subsidence is an environmental side effect of exploring and using natural resources in the process of economic development. The key points of the system for controlling land subsidence include cooperation and superior coexistence while the economy develops, exploring and using natural resources, and geological environmental safety. Using the theory and method of set pair analysis (SPA, this article anatomises the factors, effects, and transformation of land subsidence. Based on the principle of superior coexistence, this paper promotes a technical approach to the system for controlling land subsidence, in order to improve the prevention and control of geological hazards.

  4. Using land subsidence observations for groundwater model calibration

    Science.gov (United States)

    Tufekci, Nesrin; Schoups, Gerrit; Faitouri, Mohamed Al; Mahapatra, Pooja; van de Giesen, Nick; Hanssen, Ramon

    2017-04-01

    PS-InSAR derived subsidence and groundwater level time series are used to calibrate a groundwater model of Tazerbo well field, Libya, by estimating spatially varying elastic skeletal storage (Sske) and hydraulic conductivity (Hk) of the model area. Tazerbo well field is a part of the Great Man-Made River Project (GMMRP) designed with 108 wells and total pumping rate of 1 million m3/day. The water is pumped from the deep sandstone aquifer (Nubian sandstone), which is overlaid by a thick mudstone-siltstone aquitard. Pumping related deformation patterns around Tazerbo well field are obtained by processing 20 descending Envisat scenes for the period between 2004 and 2010, which yield a concentrated deformation around the well field with the maximum deformation rate around 4 mm/yr. The trends of time series of groundwater head and subsidence are in good agreement for observation wells located in the vicinity of the pumping wells and the pattern of subsidence correlates with the locations of active wells. At the beginning of calibration, different pairs of Sske and Hk are assigned at observation well locations by trial and error so that the simulation results of the forward model would approximate heads and mean linear deformation velocity at these locations. Accordingly, the estimated initial parameters suggest relatively constant Hk(5 m/d) and increasing Sske from south to north (1x10-6 m-1 - 5x10-6 m-1). In order to refine their spatial distribution, representative values of Sske and Hk are assigned at 25 equidistant points over the area, which are restricted by the predetermined values. To calibrate the parameters at assigned locations UCODE is used along with MATLAB. Once the convergence is achieved the estimated parameter values at these locations are held constant and new "in between - equidistant" locations are determined to estimate Sske and Hk in order to spatially refine their distribution. This approach is followed until the relation between observed and

  5. Comparison of allograft and polyetheretherketone (PEEK) cage subsidence rates in anterior cervical discectomy and fusion (ACDF).

    Science.gov (United States)

    Yson, Sharon C; Sembrano, Jonathan N; Santos, Edward Rainier G

    2017-04-01

    Structural allografts and PEEK cages are commonly used interbody fusion devices in ACDF. The subsidence rates of these two spacers have not yet been directly compared. The primary aim of this study was to compare the subsidence rate of allograft and PEEK cage in ACDF. The secondary aim was to determine if the presence of subsidence affects the clinical outcome. We reviewed 67 cases (117 levels) of ACDF with either structural allograft or PEEK cages. There were 85 levels (48 cases) with PEEK and 32 levels (19 cases) with allograft spacers. Anterior and posterior disc heights at each operative level were measured at immediate and 6months post-op. Subsidence was defined as a decrease in anterior or posterior disc heights >2mm. NDI of the subsidence (SG) and non-subsidence group (NSG) were recorded. Chi-square test was used to analyze subsidence rates. T-test was used to analyze clinical outcomes (α=0.05). There was no statistically significant difference between subsidence rates of the PEEK (29%; 25/85) and allograft group (28%; 9/32) (p=0.69). Overall mean subsidence was 2.3±1.7mm anteriorly and 2.6±1.2mm posteriorly. Mean NDI improvement was 11.7 (from 47.1 to 35.4; average follow-up: 12mos) for the SG and 14.0 (from 45.8 to 31.8; average follow-up: 13mos) for the NSG (p=0.74). Subsidence rate does not seem to be affected by the use of either PEEK or allograft as spacers in ACDF. Furthermore, subsidence alone does not seem to be predictive of clinical outcomes of ACDF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Land subsidence in Iran caused by widespread water reservoir overexploitation

    Science.gov (United States)

    Motagh, Mahdi; Walter, Thomas R.; Sharifi, Mohammad Ali; Fielding, Eric; Schenk, Andreas; Anderssohn, Jan; Zschau, Jochen

    2008-08-01

    The increasing demands upon groundwater resources due to expanding metropolitan and agricultural areas are a serious challenge, particularly in semiarid and arid regions. In Iran, decades of unrestrained groundwater extraction for domestic, agricultural, and industrial use have resulted in a precipitous depletion of this valuable resource. Here we show that the decline in groundwater levels is associated with land-surface deformation on local and regional scales. Combining water-level data with satellite radar observations provides evidence for the prevalence of compacting aquifers in the country. Groundwater level decline is often associated with destruction of the aquifers, which appears to be a common problem in the groundwater basins of central and northeast Iran. Global warming and future climate change will affect arid and semiarid areas in the coming decades, further augmenting hazards associated with groundwater-induced land subsidence.

  7. Thermal stresses, differential subsidence, and flexure at oceanic fracture zones

    Science.gov (United States)

    Wessel, Pal; Haxby, William F.

    1990-01-01

    Geosat geoid undulations over four Pacific fracture zones have been analyzed. After correcting for the isostatic thermal edge effect, the amplitudes of the residuals are shown to be proportional to the age offset. The shape of the residuals seems to broaden with increasing age. Both geoid anomalies and available ship bathymetry data suggest that slip must sometimes occur on the main fracture zone or secondary faults. Existing models for flexure at fracture zones cannot explain the observed anomalies. A combination model accounting for slip and including flexure from thermal stresses and differential subsidence is presented. This model accounts for lateral variations in flexural rigidity from brittle and ductile yielding due to both thermal and flexural stresses and explains both the amplitudes and the shape of the anomalies along each fracture zone. The best fitting models have mechanical plate thicknesses that are described by the depth to the 600-700 C isotherms.

  8. Modelling the subsidence of peat soils in the Dutch coastal area

    NARCIS (Netherlands)

    Hoogland, T.; Akker, van den J.J.H.; Brus, D.J.

    2012-01-01

    In large parts of the western coastal region of the Netherlands peat soils occur. Historic land use resulted in decomposition of organic matter and compaction of these soils and as a consequence the land surface subsided. Along with sea level rise and tectonic subsidence since the end of the

  9. Threat of land subsidence in and around Kolkata City and East ...

    Indian Academy of Sciences (India)

    Keywords. Kolkata; East Kolkata Wetlands; groundwater; land subsidence; groundwater potential; sustainable development. Abstract. This paper attempts to estimate the possible rate of land subsidence of Kolkata City including Salt Lake City and the adjoining East Kolkata Wetlands located at the lower part of the deltaic ...

  10. Time-varying land subsidence detected by radar altimetry: California, Taiwan and north China

    Science.gov (United States)

    Hwang, Cheinway; Yang, Yuande; Kao, Ricky; Han, Jiancheng; Shum, C. K.; Galloway, Devin L.; Sneed, Michelle; Hung, Wei-Chia; Cheng, Yung-Sheng; Li, Fei

    2016-06-01

    Contemporary applications of radar altimetry include sea-level rise, ocean circulation, marine gravity, and icesheet elevation change. Unlike InSAR and GNSS, which are widely used to map surface deformation, altimetry is neither reliant on highly temporally-correlated ground features nor as limited by the available spatial coverage, and can provide long-term temporal subsidence monitoring capability. Here we use multi-mission radar altimetry with an approximately 23 year data-span to quantify land subsidence in cropland areas. Subsidence rates from TOPEX/POSEIDON, JASON-1, ENVISAT, and JASON-2 during 1992-2015 show time-varying trends with respect to displacement over time in California’s San Joaquin Valley and central Taiwan, possibly related to changes in land use, climatic conditions (drought) and regulatory measures affecting groundwater use. Near Hanford, California, subsidence rates reach 18 cm yr-1 with a cumulative subsidence of 206 cm, which potentially could adversely affect operations of the planned California High-Speed Rail. The maximum subsidence rate in central Taiwan is 8 cm yr-1. Radar altimetry also reveals time-varying subsidence in the North China Plain consistent with the declines of groundwater storage and existing water infrastructure detected by the Gravity Recovery And Climate Experiment (GRACE) satellites, with rates reaching 20 cm yr-1 and cumulative subsidence as much as 155 cm.

  11. Influence the condition land subsidence and groundwater impact of Jakarta coastal area

    Science.gov (United States)

    Rahman, S.; Sumotarto, U.; Pramudito, H.

    2018-01-01

    Jakarta has been experiencing land subsidence for ten years due toerecting weight building and intensive extraction of groundwater for society drink water through ground water wells. Many groundwater extraction for drinkingwater has caused intensive scouring of land rock and further triggering land subsidence developed widely in coastal area of Jakarta. Measurement of the land subsidence has been performed by various experts and institutes. Between 1974 to 2010 subsidence has happened between 3 to 4.1 meters especially in Jakarta coastal area. Two major causes of the subsidence are identified. The first major cause is a result of erecting weight building such as hotels, appartments, and various human activities buildings. The second major cause is extracting ground water from aquifers bellow Jakarta land due to water deep wells down to the aquifer and traditional shallow water well of shallow or subsurface uncovered ground water. Weighter building and higher debit of water flow from deep water wells has fastened and deepened the land subsidence. Continuous measurement of land subsidence by means of geodetic as well as geophysical earth behaviour measurements need to be performed to monitor the rate, location as well as mapping of the land subsidence.

  12. Time-varying land subsidence detected by radar altimetry: California, Taiwan and north China

    Science.gov (United States)

    Hwang, Cheinway; Yang, Yuande; Kao, Ricky; Han, Jiancheng; Shum, C.K.; Galloway, Devin L.; Sneed, Michelle; Hung, Wei-Chia; Cheng, Yung-Sheng; Li, Fei

    2016-01-01

    Contemporary applications of radar altimetry include sea-level rise, ocean circulation, marine gravity, and ice sheet elevation change. Unlike InSAR and GNSS, which are widely used to map surface deformation, altimetry is neither reliant on highly temporally-correlated ground features nor as limited by the available spatial coverage, and can provide long-term temporal subsidence monitoring capability. Here we use multi-mission radar altimetry with an approximately 23 year data-span to quantify land subsidence in cropland areas. Subsidence rates from TOPEX/POSEIDON, JASON-1, ENVISAT, and JASON-2 during 1992–2015 show time-varying trends with respect to displacement over time in California’s San Joaquin Valley and central Taiwan, possibly related to changes in land use, climatic conditions (drought) and regulatory measures affecting groundwater use. Near Hanford, California, subsidence rates reach 18 cm/yr with a cumulative subsidence of 206 cm, which potentially could adversely affect operations of the planned California High-Speed Rail. The maximum subsidence rate in central Taiwan is 8 cm/yr. Radar altimetry also reveals time-varying subsidence in the North China Plain consistent with the declines of groundwater storage and existing water infrastructure detected by the Gravity Recovery And Climate Experiment (GRACE) satellites, with rates reaching 20 cm/yr and cumulative subsidence as much as 155 cm.

  13. Time-varying land subsidence detected by radar altimetry: California, Taiwan and north China.

    Science.gov (United States)

    Hwang, Cheinway; Yang, Yuande; Kao, Ricky; Han, Jiancheng; Shum, C K; Galloway, Devin L; Sneed, Michelle; Hung, Wei-Chia; Cheng, Yung-Sheng; Li, Fei

    2016-06-21

    Contemporary applications of radar altimetry include sea-level rise, ocean circulation, marine gravity, and icesheet elevation change. Unlike InSAR and GNSS, which are widely used to map surface deformation, altimetry is neither reliant on highly temporally-correlated ground features nor as limited by the available spatial coverage, and can provide long-term temporal subsidence monitoring capability. Here we use multi-mission radar altimetry with an approximately 23 year data-span to quantify land subsidence in cropland areas. Subsidence rates from TOPEX/POSEIDON, JASON-1, ENVISAT, and JASON-2 during 1992-2015 show time-varying trends with respect to displacement over time in California's San Joaquin Valley and central Taiwan, possibly related to changes in land use, climatic conditions (drought) and regulatory measures affecting groundwater use. Near Hanford, California, subsidence rates reach 18 cm yr(-1) with a cumulative subsidence of 206 cm, which potentially could adversely affect operations of the planned California High-Speed Rail. The maximum subsidence rate in central Taiwan is 8 cm yr(-1). Radar altimetry also reveals time-varying subsidence in the North China Plain consistent with the declines of groundwater storage and existing water infrastructure detected by the Gravity Recovery And Climate Experiment (GRACE) satellites, with rates reaching 20 cm yr(-1) and cumulative subsidence as much as 155 cm.

  14. STUDY OF THE PIEZOMETRIC SURFACE AND HYDROCOMPACTION AT CONFINED AQUIFER CAUSED THE LAND SUBSIDENCE IN SEMARANG

    Directory of Open Access Journals (Sweden)

    Fahrudin Fahrudin

    2012-02-01

    Full Text Available Semarang city has experienced of the land subsidence that be caused by intake groundwater in confined aquiferabundant. The land subsidence happened during range of time 20 years, it’s critical boundary so that result theenvironmental damage. Hence needed a study of cause of the land subsidence. This study aim to know theposition of piezometric surface and also explain the mechanism hydrogeology when happened the landsubsidence. The study of spreading aquifer has been done by the analysis of secondary data which is in the formof drilling log data, piezometric surface and soil mechanics test obtained from PLG (Environmental Center ofGeology Bandung. Later then, between the land subsidence and piezometric surface be overlay becamezonation. From the data made a analysis of cause of the land subsidence. This aquifer has the land subsidence.The land subsidence explainable with the experienced phenomenon fact for example degradation of piezometricsurface at confined aquifer and process of hydrocompaction. That process influenced by two factors that areassess the pore number (e and specific gravity (Gs. The degradation of piezometric surface formed the trapezeof water table until 20 m from sea level with the mean 0.7 - 1.1 m/year. Hydrocompaction cause the degradationof number of mean pore 0.145 - 0.5 and specific gravity 0.009 - 0.073 . The degradation of piezometric surfaceand process the hydrocompaction cause the fast of land subsidence around 0.5 - 1.75 cm/year.

  15. Geotechnical and Geological Aspects of Differential Subsidence in the Skaw Spit, Denmark

    DEFF Research Database (Denmark)

    Andersen, Holger Lykke; Thorsen, Grete; Hauerbach, P.

    1996-01-01

    Local differential subsidence has been observed by means of repeated precise levellings in the township of Skagen at the northernmost tip of the Skaw Spit in Jutland. We have l studied the possible causes of the subsidence. Oedometer tests have been carried out on undisturbed clayey samples from ...

  16. Subsidence hazards as a consequence of dam, reservoir and tunnel construction.

    Directory of Open Access Journals (Sweden)

    Milanovic Petar

    2002-01-01

    Full Text Available Considering all man-made structures in karst areas, dams, reservoirs and tunnels are the most vulnerable in relation to induced subsidence and caverns. Reservoirs that are located entirely or partially on karstified rocks covered with unconsolidated sediments are especially subsidence-prone. As a consequence of induced subsidence a number of reservoirs in karst areas failed and were never fully filled. Such subsidence formation is very damaging because the development is unpredictable and practically instantaneous. Reservoirs in karst areas may fail to fill despite an extensive site investigation programs and sealing treatment. Every problem is unique and past experiences are never repeated. This review focuses on the meaning and consequences of selected prominent examples, but the conclusions reached are valid for subsidence problems related to man-made structures in general.

  17. Land subsidence threats and its management in the North Coast of Java

    Science.gov (United States)

    Sarah, D.; Soebowo, E.

    2018-02-01

    Cities on the north coast of Java such as Jakarta, Semarang, Pekalongan, and Surabaya are vulnerable to environmental pressures such as sea level change and land subsidence. Land subsidence can be caused by natural and anthropogenic processes. Geologically, the north coastal plain of Java consists of unconsolidated Holocene alluvial deposit. The recent alluvial deposit is prone to compaction, and further aggravated by anthropogenic forces such as groundwater extraction and land development. Understanding the complex interaction of natural and manmade factors is essential to establish mitigation strategy. Although the impacts of land subsidence are widely felt, many do not realize that land subsidence is taking place. This paper presents a brief review of the land subsidence threats in the North coast of Java and proposes a recommendation for suitable management response.

  18. Subsidence in the Central Valley, California 2007 - present measured by InSAR

    Science.gov (United States)

    Farr, T. G.; Liu, Z.; Jones, C. E.

    2015-12-01

    Subsidence caused by groundwater pumping in the rich agricultural area of California's Central Valley has been a problem for decades. Over the last few years, interferometric synthetic aperture radar (InSAR) observations from satellite and aircraft platforms have been used to produce maps of subsidence with ~cm accuracy. For this study, we have obtained and analyzed Japanese PALSAR data for 2006 - 2011, Canadian Radarsat-1 data for 2011 - 2013, Radarsat-2 data for 2012 - 2015, and ESA's Sentinel-1A for 2015 and produced maps of subsidence for those periods. High resolution InSAR data were also acquired along the California Aqueduct by the NASA UAVSAR from 2013 - 2015. Using multiple scenes acquired by these systems, we were able to produce the time histories of subsidence at selected locations and transects showing how subsidence varies both spatially and temporally. The maps show that subsidence is continuing in areas with a history of subsidence and that the rates and areas affected have increased due to increased groundwater extraction during the extended western US drought. The high resolution maps from UAVSAR were used to identify and quantify new, highly localized areas of accelerated subsidence along the California Aqueduct that occurred in 2014. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Geographic Information System (GIS) files are being furnished to DWR for further analysis of the 4 dimensional subsidence time-series maps. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

  19. IMPACT OF SUBSIDIZED SCHOOL FUNDING ON INFRASTRUCTURE DEVELOPMENT IN PUBLIC SECONDARY SCHOOLS IN SABATIA SUB-COUNTY, VIHIGA COUNTY - KENYA

    National Research Council Canada - National Science Library

    Maende Justus Barasa; Mbayah Judith Tsisiga

    2014-01-01

    .... In this regard, Kenyan government in 2008 began subsidized Secondary education. The purpose of this study therefore was to establish the role of subsidized secondary school funding programme in enhancing infrastructural development in Sabatia Sub-County...

  20. Impact of rock salt creep law choice on subsidence calculations for hydrocarbon reservoirs overlain by evaporite caprocks

    NARCIS (Netherlands)

    Marketos, G.; Spiers, C.J.; Govers, R.

    2016-01-01

    Accurate forward modeling of surface subsidence above producing hydrocarbons reservoirs requires an understanding of the mechanisms determining how ground deformation and subsidence evolve. Here we focus entirely on rock salt, which overlies a large number of reservoirs worldwide, and specifically

  1. Assessing the long-term impact of subsidence and global climate change on emergency evacuation routes in coastal Louisiana.

    Science.gov (United States)

    2012-12-01

    Subsidence forecast models for coastal Louisiana were developed to estimate the change in surface elevations of evacuation routes for the years 2015, 2025, 2050, and 2100. Geophysical and anthropogenic subsidence estimates were derived from on-going ...

  2. Subsidence due to peat compaction and oxidation in built-up deltas

    Science.gov (United States)

    van Asselen, Sanneke; Erkens, Gilles; Stouthamer, Esther; Hefting, Mariet

    2017-04-01

    Deltas are often densely populated, and are predicted to face continued population growth and urbanization. At the same time, deltas are threatened by relative sea-level rise due to the combined effect of land subsidence and global sea-level rise. Many deltaic sequences contain large amounts of peat. In such organo-clastic deltas, peat compaction and oxidation are important contributors to total subsidence. Especially in built-up areas, (differential) subsidence and associated increased flood risk, result in high costs related to damage to buildings and infrastructure. Yet, subsidence due to peat compaction and oxidation in built-up deltaic areas has not been given sufficient attention. These processes have mostly been studied separately, in rural or pristine areas. To develop tailor-made subsidence management strategies for built-up areas in organo-clastic deltas, a thorough understanding of peat compaction and oxidation, and their spatial and temporal variability, is needed. Therefore, we investigated the relative contribution of both peat compaction and oxidation to subsidence in three built-up areas in the Rhine-Meuse delta, The Netherlands. We used (1) borehole data to construct lithological cross sections of the Holocene sequence, (2) dry bulk density and organic-matter content measurements to assess the degree of compaction, and (3) respiration measurements to determine the oxidation potential. We assessed subsidence due to peat compaction or oxidation of up to 2 meters over the last 1000 years, and subsidence rates of up to 16 cm·yr-1. The amount and rate of subsidence due to peat compaction and oxidation, and the relative contribution of both processes, is however highly variable in time and space, depending on the Holocene sequence composition, loading conditions, and groundwater-table lowering. For example, subsidence in a sequence with a heavily loaded peat layer will have been mostly caused by peat compaction, while subsidence in a sequence with a

  3. Regional subsidence history and 3D visualization with MATLAB of the Vienna Basin, central Europe

    Science.gov (United States)

    Lee, E.; Novotny, J.; Wagreich, M.

    2013-12-01

    This study reconstructed the subsidence history by the backstripping and 3D visualization techniques, to understand tectonic evolution of the Neogene Vienna Basin. The backstripping removes the compaction effect of sediment loading and quantifies the tectonic subsidence. The amount of decompaction was calculated by porosity-depth relationships evaluated from seismic velocity data acquired from two boreholes. About 100 wells have been investigated to quantify the subsidence history of the Vienna Basin. The wells have been sorted into 10 groups; N1-4 in the northern part, C1-4 in the central part and L1-2 in the northernmost and easternmost parts, based on their position within the same block bordered by major faults. To visualize 3D subsidence maps, the wells were arranged to a set of 3D points based on their map location (x, y) and depths (z1, z2, z3 ...). The division of the stratigraphic column and age range was arranged based on the Central Paratethys regional Stages. In this study, MATLAB, a numerical computing environment, was used to calculate the TPS interpolation function. The Thin-Plate Spline (TPS) can be employed to reconstruct a smooth surface from a set of 3D points. The basic physical model of the TPS is based on the bending behavior of a thin metal sheet that is constrained only by a sparse set of fixed points. In the Lower Miocene, 3D subsidence maps show strong evidence that the pre-Neogene basement of the Vienna Basin was subsiding along borders of the Alpine-Carpathian nappes. This subsidence event is represented by a piggy-back basin developed on top of the NW-ward moving thrust sheets. In the late Lower Miocene, Group C and N display a typical subsidence pattern for the pull-apart basin with a very high subsidence event (0.2 - 1.0 km/Ma). After the event, Group N shows remarkably decreasing subsidence, following the thin-skinned extension which was regarded as the extension model of the Vienna Basin in the literature. But the subsidence in

  4. Average course approximation of measured subsidence and inclinations of mining area by smooth splines

    Directory of Open Access Journals (Sweden)

    Justyna Orwat

    2017-01-01

    Full Text Available The results of marking average courses of subsidence measured on the points of measuring line no. 1 of the “Budryk” Hard Coal Mine, set approximately perpendicularly to a face run of four consecutively mined longwalls in coal bed 338/2 have been presented in the article. Smooth splines were used to approximate the average course of measured subsidence after subsequent exploitation stages. The minimising of the sum of the squared differences between the average and forecasted subsidence, using J. Bialek's formula, was used as a selection criterion of parameter values of smoothing an approximating function. The parameter values of this formula have been chosen in order to match forecasted subsidence with measured ones. The average values of inclinations have been calculated on the basis of approximated values of observed subsidence. It has been shown that by doing this the average values of extreme measured inclinations can be obtained in almost the same way as extreme observed inclinations. It is not necessary to divide the whole profile of a subsidence basin into parts. The obtained values of variability coefficients of a random scattering for subsidence and inclinations are smaller than their values which occur in the literature.

  5. STUDY ON LAND SUBSIDENCE INCANGZHOU AREA BASEDON SENTINEL-1A/B DATA

    Directory of Open Access Journals (Sweden)

    H. Zhou

    2017-09-01

    Full Text Available This paper, obtaining 39scenesof images of the Sentinel-1 A/B, monitored the Cangzhou area subsidence from Mar. 2015 to Dec. 2016 basing on using PS-InSAR technique. The annual average subsidence rate and accumulative subsidence were obtained. The results showed that the ground surface of Xian County,Cang County, Cangzhou urban area had a rebound trend; Qing County, the east of Cang County ,the west of Nanpi County and Dongguang County appeared obvious subsidence, and the accumulated subsidence in Hezhuang village of Dongguang County reached 47 mm. And from that the main reason leading to these obvious subsidence was over-exploitation of ground-water. At last, it analyzed the settlement of the High-Speed Railway (HR which was north from the Machang town of QingCounty and south to the Lian town of Dongguang County in Cangzhou.The relative deformation of the HR between the two sections which was Lierzhuang village of Cang County and Chenxin village of Nanpi County arrived at 30 mm. Moreover, this paper discussed the application of Sentinel-1 A/B SAR images in monitoring urban land subsidence and the results provided important basic data for the relevant departments.

  6. Houston-Galveston Bay area, Texas, from space; a new tool for mapping land subsidence

    Science.gov (United States)

    Stork, Sylvia V.; Sneed, Michelle

    2002-01-01

    Interferometric Synthetic Aperture Radar (InSAR) is a powerful new tool that uses radar signals to measure displacement (subsidence and uplift) of the Earth's crust at an unprecedented level of spatial detail and high degree of measurement resolution.The Houston-Galveston Bay area, possibly more than any other metropolitan area in the United States, has been adversely affected by land subsidence. Extensive subsidence, caused mainly by ground-water pumping but also by oil and gas extraction, has increased the frequency of flooding, caused extensive damage to industrial and transportation infrastructure, motivated major investments in levees, reservoirs, and surfacewater distribution facilities, and caused substantial loss of wetland habitat. Ongoing patterns of subsidence in the Houston area have been carefully monitored using borehole extensometers, Global Positioning System (GPS) and conventional spirit-leveling surveys, and more recently, an emerging technology—Interferometric Synthetic Aperture Radar (InSAR)—which enables development of spatially-detailed maps of land-surface displacement over broad areas. This report, prepared by the U.S. Geological Survey (USGS) in cooperation with the U.S. Fish and Wildlife Service, briefly summarizes the history of subsidence in the area and the local consequences of subsidence and describes the use of InSAR as one of several tools in an integrated subsidence-monitoring program in the area.

  7. Application of decision tree model for the ground subsidence hazard mapping near abandoned underground coal mines.

    Science.gov (United States)

    Lee, Saro; Park, Inhye

    2013-09-30

    Subsidence of ground caused by underground mines poses hazards to human life and property. This study analyzed the hazard to ground subsidence using factors that can affect ground subsidence and a decision tree approach in a geographic information system (GIS). The study area was Taebaek, Gangwon-do, Korea, where many abandoned underground coal mines exist. Spatial data, topography, geology, and various ground-engineering data for the subsidence area were collected and compiled in a database for mapping ground-subsidence hazard (GSH). The subsidence area was randomly split 50/50 for training and validation of the models. A data-mining classification technique was applied to the GSH mapping, and decision trees were constructed using the chi-squared automatic interaction detector (CHAID) and the quick, unbiased, and efficient statistical tree (QUEST) algorithms. The frequency ratio model was also applied to the GSH mapping for comparing with probabilistic model. The resulting GSH maps were validated using area-under-the-curve (AUC) analysis with the subsidence area data that had not been used for training the model. The highest accuracy was achieved by the decision tree model using CHAID algorithm (94.01%) comparing with QUEST algorithms (90.37%) and frequency ratio model (86.70%). These accuracies are higher than previously reported results for decision tree. Decision tree methods can therefore be used efficiently for GSH analysis and might be widely used for prediction of various spatial events. Copyright © 2013. Published by Elsevier Ltd.

  8. Planning for development on land that is potentially prone to subsidence in England

    Energy Technology Data Exchange (ETDEWEB)

    Brook, D.; Marker, B.

    2008-08-15

    Subsidence problems that may constrain, add to the costs of, or delay development are widespread in England. Extensive sources of information are available, such as datasets held by the British Geological Survey and the Coal Authority, but are not always used fully in planning for development and determining planning applications. Planning Policy Guidance (PPG) Note 14 on instability was published in 1990 and later augmented by a specific Annex 2 on subsidence and planning. That guidance improved the consideration given to subsidence in planning but key advances tended to be focused on specific areas selected by Government for demonstration projects and a major derelict land reclamation initiative. Elsewhere, implementation has been patchy. Although subsidence issues tended to be taken into account in areas of extensive past underground mining, appreciation of the issues has been more difficult to establish where potential subsidence relates to isolated mining or natural underground cavities. Recent reform of the planning system has led to continuing replacement of PPGs by a new series of Planning Policy Statements (PPSs). There are currently no plans to bring PPG 14 or its annexes into a PPS format and, therefore, a risk that it will gradually be forgotten and that good planning responses to subsidence may decline. Sustainability appraisal of spatial plans and environmental impact assessments of development proposals could help to ensure that this important issue is not overlooked, but existing guidance on assessments does not refer explicitly to subsidence.

  9. Study on Land Subsidence Incangzhou Area Basedon SENTINEL-1A/B Data

    Science.gov (United States)

    Zhou, H.; Wang, Y.; Yan, S.

    2017-09-01

    This paper, obtaining 39scenesof images of the Sentinel-1 A/B, monitored the Cangzhou area subsidence from Mar. 2015 to Dec. 2016 basing on using PS-InSAR technique. The annual average subsidence rate and accumulative subsidence were obtained. The results showed that the ground surface of Xian County,Cang County, Cangzhou urban area had a rebound trend; Qing County, the east of Cang County ,the west of Nanpi County and Dongguang County appeared obvious subsidence, and the accumulated subsidence in Hezhuang village of Dongguang County reached 47 mm. And from that the main reason leading to these obvious subsidence was over-exploitation of ground-water. At last, it analyzed the settlement of the High-Speed Railway (HR) which was north from the Machang town of QingCounty and south to the Lian town of Dongguang County in Cangzhou.The relative deformation of the HR between the two sections which was Lierzhuang village of Cang County and Chenxin village of Nanpi County arrived at 30 mm. Moreover, this paper discussed the application of Sentinel-1 A/B SAR images in monitoring urban land subsidence and the results provided important basic data for the relevant departments.

  10. Mechanisms of crustal uplift and subsidence at the Yellowstone caldera, Wyoming

    Science.gov (United States)

    Dzurisin, D.; Yamashita, K.M.; Kleinman, J.W.

    1994-01-01

    Leveling surveys in 1923, 1976, and each year from 1983 to 1993 have shown that the east-central part of the Yellowstone caldera, near the base of the Sour Creek resurgent dome, rose at an average rate of 14??1 mm/year from 1923 to 1976 and 22??1 mm/year from 1976 to 1984. In contrast, no detectable movement occurred in the same area from 1984 to 1985 (-2??5 mm/year), and from 1985 to 1993 the area subsided at an average rate of 19??1 mm/year. We conclude that uplift from 1923 to 1984 was caused by: (1) pressurization of the deep hydrothermal system by fluids released from a crystallizing body of rhyolite magma beneath the caldera, then trapped beneath a self-sealed zone near the base of the hydrothermal system; and (2) aseismic intrusions of magma into the lower part of the sub-caldera magma body. Subsidence since 1985 is attributed to: (1) depressurization and fluid loss from the deep hydrothermal system, and (2) sagging of the caldera floor in response to regional crustal extension. Future intrusions might trigger renewed eruptive activity at Yellowstone, but most intrusions at large silicic calderas seem to be accommodated without eruptions. Overpressurization of the deep hydrothermal system could conceivably result in a phreatic or phreatomagmatic eruption, but this hazard is mitigated by episodic rupturing of the self-sealed zone during shallow earthquake swarms. Historical ground movements, although rapid by most geologic standards, seem to be typical of inter-eruption periods at large, mature, silicic magma systems like Yellowstone. The greatest short-term hazards posed by continuing unrest in the Yellowstone region are: (1) moderate to large earthquakes (magnitude 5.5-7.5), with a recurrence interval of a few decdes; and (2) small hydrothermal explosions, most of which affect only a small area (<0.01 km2), with a recurrence interval of a few years. ?? 1994 Springer-Verlag.

  11. Groundwater-pumping optimization for land-subsidence control in Beijing plain, China

    Science.gov (United States)

    Qin, Huanhuan; Andrews, Charles B.; Tian, Fang; Cao, Guoliang; Luo, Yong; Liu, Jiurong; Zheng, Chunmiao

    2018-01-01

    Beijing, in the North China plain, is one of the few megacities that uses groundwater as its main source of water supply. Groundwater accounts for about two-thirds of the city's water supply, and during the past 50 years the storage depletion from the unconsolidated aquifers underlying the city has been >10.4 billion m3. By 2010, groundwater pumping in the city had resulted in a cumulative subsidence of greater than 100 mm in an area of about 3,900 km2, with a maximum cumulative subsidence of >1,200 mm. This subsidence has caused significant social and economic losses in Beijing, including significant damage to underground utilities. This study was undertaken to evaluate various future pumping scenarios to assist in selecting an optimal pumping scenario to minimize overall subsidence, meet the requirements of the Beijing Land Subsidence Prevention Plan (BLSPP 2013-2020), and be consistent with continued sustainable economic development. A numerical groundwater and land-subsidence model was developed for the aquifer system of the Beijing plain to evaluate land subsidence rates under the possible future pumping scenarios. The optimal pumping scenario consistent with the evaluation constraints is a reduction in groundwater pumping from three major pumping centers by 100, 50 and 20%, respectively, while maintaining an annual pumping rate of 1.9 billion m3. This scenario's land-subsidence rates satisfy the BLSPP 2013-2020 and the pumping scenario is consistent with continued economic development. It is recommended that this pumping scenario be adopted for future land-subsidence management in Beijing.

  12. Dynamic Subsidence across the Late Cretaceous Western Interior Basin in Response to Farallon Slab Subduction

    Science.gov (United States)

    Liu, S.; Nummedal, D.; Liu, L.

    2015-12-01

    The United States Cretaceous Western Interior Basin has long been considered a foreland basin, driven by the Sevier thrust and associated basin sediment loads. However, flexural studies demonstrate that this effect exists only within a narrow band in front of the thrust belt. Most of the basin appears to be due to mantle flow-induced dynamic subsidence associated with Farallon plate subduction. Here we show how the components of evolving long-wavelength dynamic subsidence and flexural subsidence created the accommodation space and controlled the stratigraphy across the western United Sates, based on the correlated stratigraphic sections across central Utah-Colorado and southern Wyoming.These backstripped subsidence data reveal a component of continuously evolving long-wavelength dynamic subsidence, in addition to subsidence driven by the Sevier thrust belt and associated sediment loads. The loci of maximum rates of this dynamic subsidence moved eastward from ~98 to 74 Ma in phase with the west-to-east passage of the Farallon slab, as reconstructed from tomography based on quantitative inverse models. These subsidence data allow testing of existing subduction models and confirm the dynamic-topography driven nature of the Western Interior Basin. The results seem to support that the depocenters track the trough of dynamic subsidence with ca.18 Myr cycles through time and space and the stratigraphic patterns of large-scale progradation, eastward migration of depocenter, and regional clinoform-like downlap are related with the dynamic subsidence. Interpretation of these data also provides more insights into the repeated, ca.2 to 6 Myr cycles of thrust-induced subsidence in front of the thrust belt, which control the local eastward progradation of the sand bodies from the thrust belt. The dynamic, flexural subsidence and eustatic sea level changes interacted and controlled the timing and distribution of unconformities. Our work shows how the stratigraphy precisely

  13. Subsidence of titanium straight stems in combination with highly viscous bone cement

    OpenAIRE

    Hendrich, Christian; Sauer, Ulf; Albrecht, Tobias; Rader, Christof P.

    2005-01-01

    Varying results and a high rate of subsidence have been reported for the straight femoral stem (M.E. Müller) made of titanium alloy. We examined subsidence in 135 titanium-alloy straight stems implanted with high viscosity cement after 68.8±11.5 months using a digital high-precision method (EBRA-FCA). One revised implant showed a subsidence of 14.6 mm and another 2.5 mm over 5 years. A third implant without migration was found to be loose. The 122 implants without loosening showed a mean subs...

  14. Prediction maps of land subsidence caused by groundwater exploitation in Hanoi, Vietnam

    Directory of Open Access Journals (Sweden)

    Thinh Hong Phi

    2015-12-01

    Full Text Available The article presents study results of the land subsidence caused by groundwater exploitation in Hanoi, Vietnam. The study includes collection and analysis of data on geology, hydrology, soil properties and settlements observed at 10 monitoring stations as well as models of the time-dependent settlement. The calculated settlements are relatively close to actual monitoring data. The models were done for prediction of the land subsidence at 92 selected points by the finite element method. Prediction maps are made for prediction of the land subsidence in 2020 and 2030. Recommendations are proposed for potential zones of groundwater exploitation in Hanoi.

  15. DINSAR EXPERIMENTS FOR SHANGHAI GROUND SUBSIDENCE MONITORING BY USING ALOS PALSAR DATA

    OpenAIRE

    Wu, Jicang; Zhang, Lina; Ban, Baosong; Li, Tao; XU Caijun; Wen, Yamao

    2011-01-01

    The Advanced Land Observing Satellite (ALOS) PALSAR data is used to take two pass interferometry for extraction of ground subsidence in Shanghai China. At first a set of two pass interferometry with baseline less than 1km are taken and corresponding coherence factor are used to indentify persistent scatterers (PS) so as to form a time series of differential phase of every PSs. A linear subsidence model is applied at all PS points and the subsidence rates of all PSs are obtained through a stac...

  16. Application of Cold Formed Steel Framing Structures for Construction in Zones Affected by Land Subsidence

    Directory of Open Access Journals (Sweden)

    Correa L.-O.

    2012-09-01

    Full Text Available The main objective of this research project is to study the application of structural systems based on light gauge cold-formed steel framing to housing in subsidence zones, having the following scopes: characterize the typical settlements in a discontinuity due to subsidence, to build a laboratory facility to simulate these settlements, to simulate and to evaluate numerically and in laboratory in a full scale model the structural performance of a house subjected to settlements due to subsidence, in terms of its stresses and strains and, eventually, its capacity of retrieval to its nondeformed shape.

  17. Impact of global change on ground subsidence related to aquifer exploitation. The case of the Vega de Granada aquifer (SE Spain)

    Science.gov (United States)

    Pulido-Velazquez, David; María Mateos, Rosa; Rueda, Ramon; Pegalajar-Cuellar, Manuel; Ezquerro, Pablo; Béjar, Marta; Herrera, Gerardo; Collados-Lara, Antonio-Juan

    2017-04-01

    better explains the relationship between subsidence, hydraulic changes and the remaining independent variables. This methodology has been applied to the Vega de Granada aquifer system (Granada, SE Spain). The Vega de Granada detrital aquifer (with an extension of 200 km2) is one of the largest groundwater reservoirs in Andalusia and it is considered as strategic for the economy of this semi-arid region. Ground motion was monitored by exploiting SAR images from ENVISAT (2003-2009), Cosmo-SkyMed (2011-2014) and Sentinel-1A (2015-2016). PSInSAR results show an inelastic deformation in the aquifer and land surface displacements values up to -55 mm. The most widespread land subsidence is detected for the ENVISAT period (2003-2009), which coincided with a dry, long period in the region. The highest recorded data accounts up to 10 mm/yr in surface displacement velocity, which were detected in the central part of the aquifer, where many villages are located. For this period, a good correlation between groundwater level depletion and the augmentation of the subsidence average velocity is obtained, and light hydraulic head changes (< 2 m) have a rapid ground motion response. This research will contribute to assess a sustainable management plan of this vital aquifer, taking into account critical levels of groundwater level depletion to avoid land subsidence on the identified vulnerable areas and during drought critical scenarios. This research has been supported by the CGL2013-48424-C2-2-R (MINECO) project.

  18. Bacterial growth efficiency in a tropical estuary: Seasonal variability subsidized by allochthonous carbon

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.S.P.; Nair, S.; Chandramohan, D.

    between primary production of carbon and amount of carbon consumed by bacteria. Despite the two systems being subsidized by allochthonous inputs, the low BGE in the coastal waters may be attributable to the nature and time interval in the supply...

  19. Cost-benefit analysis : substituting ground transportation for subsidized essential air services.

    Science.gov (United States)

    2015-12-01

    Since the Airline Deregulation Act of 1978, the U.S. Department of Transportation (DOT) has been subsidizing air service to : small rural communities through the Essential Air Service (EAS) program. The original intent of the program was to maintain ...

  20. InSAR detects increase in surface subsidence caused by an Arctic tundra fire

    Science.gov (United States)

    Liu, Lin; Jafarov, Elchin E.; Schaefer, Kevin M.; Jones, Benjamin M.; Zebker, Howard A.; Williams, Christopher A.; Rogan, John; Zhang, Tingjun

    2014-01-01

    Wildfire is a major disturbance in the Arctic tundra and boreal forests, having a significant impact on soil hydrology, carbon cycling, and permafrost dynamics. This study explores the use of the microwave Interferometric Synthetic Aperture Radar (InSAR) technique to map and quantify ground surface subsidence caused by the Anaktuvuk River fire on the North Slope of Alaska. We detected an increase of up to 8 cm of thaw-season ground subsidence after the fire, which is due to a combination of thickened active layer and permafrost thaw subsidence. Our results illustrate the effectiveness and potential of using InSAR to quantify fire impacts on the Arctic tundra, especially in regions underlain by ice-rich permafrost. Our study also suggests that surface subsidence is a more comprehensive indicator of fire impacts on ice-rich permafrost terrain than changes in active layer thickness alone.

  1. Subsidence feature discrimination using deep convolutional neral networks in synthetic aperture radar imagery

    CSIR Research Space (South Africa)

    Schwegmann, Colin P

    2017-07-01

    Full Text Available International Geoscience and Remote Sensing Symposium (IGARSS), 23-28 July 2017, Fort Worth, TX, USA SUBSIDENCE FEATURE DISCRIMINATION USING DEEP CONVOLUTIONAL NEURAL NETWORKS IN SYNTHETIC APERTURE RADAR IMAGERY Schwegmann, Colin P Kleynhans, Waldo...

  2. Is land subsidence increasing the exposure to sea level rise in Alexandria, Egypt?

    National Research Council Canada - National Science Library

    Wöppelmann, Guy; Le Cozannet, Gonéri; Michele, Marcello; Raucoules, Daniel; Cazenave, Anny; Garcin, Manuel; Hanson, Susan; Marcos, Marta; Santamaría‐Gómez, Alvaro

    2013-01-01

    Delta margins are subject to relatively high rates of land subsidence and have the potential to significantly exacerbate future changes in sea levels predicted by global warming models used in impact studies...

  3. Subsidence and volcanism of the Haleakala Ridge, Hawaii

    Science.gov (United States)

    Moore, J.G.; Clague, D.A.; Ludwig, K. R.; Mark, R.K.

    1990-01-01

    Side-looking sonar (GLORIA) mapping has revealed a series of four arcuate bands of high sonic backscatter on the crest of the Haleakala Ridge, a major rift-zone ridge extending 135 km east of the island of Maui. Dredge recovery indicates that the shallowest of these bands is a drowned coral reef, and the deeper bands are also inferred to be coral reefs. The reefs occur above a prominent submarine bench 1500-2500 m deep on the ridge (H-terrace) that marks the shoreline at the end of vigorous shield building of Haleakala volcano when lava flows ceased crossing and reworking the shoreline. Since their growth these reefs have subsided as much as 2200 m and have tilted systematically about 20 m/km southward as a result of post-reef volcanic loading on the island of Hawaii, whose center of mass is about directly south of the Haleakala Ridge. The 234U/238U age of the dredged coral is 750 ?? 13 ka, in reasonable agreement with an age of 850 ka for the underlying H terrace previously estimated from its relationship to other dated reefs to the southwest. Basalt glass fragments dredged from the Haleakala Ridge below the H terrace are tholeiitic and contain high sulfur indicative of eruption in water deeper than 200 m. Basalt glass fragments associated with the reefs above the H terrace are dominantly tholeiitic and contain intermediate sulfur contents, indicative of subaqueous eruption in shallow, near-shore conditions. One alkalic glass fragment was recovered above the H terrace. These relations indicate that the morphologic end of shield building as recorded by construction of the H terrace was not accompanyed by a change from tholeiitic to alkalic basalt; instead tholeiite eruptions continued for some time before the erupted lava became alkalic. ?? 1990.

  4. Subsidence of ash-flow calderas: Relation to caldera size and magma-chamber geometry

    Science.gov (United States)

    Lipman, P.W.

    1997-01-01

    Diverse subsidence geometries and collapse processes for ash-flow calderas are inferred to reflect varying sizes, roof geometries, and depths of the source magma chambers, in combination with prior volcanic and regional tectonic influences. Based largely on a review of features at eroded pre-Quaternary calderas, a continuum of geometries and subsidence styles is inferred to exist, in both island-arc and continental settings, between small funnel calderas and larger plate (piston) subsidences bounded by arcuate faults. Within most ring-fault calderas, the subsided block is variably disrupted, due to differential movement during ash-flow eruptions and postcollapse magmatism, but highly chaotic piecemeal subsidence appears to be uncommon for large-diameter calderas. Small-scale downsag structures and accompanying extensional fractures develop along margins of most calderas during early stages of subsidence, but downsag is dominant only at calderas that have not subsided deeply. Calderas that are loci for multicyclic ash-flow eruption and subsidence cycles have the most complex internal structures. Large calderas have flared inner topographic walls due to landsliding of unstable slopes, and the resulting slide debris can constitute large proportions of caldera fill. Because the slide debris is concentrated near caldera walls, models from geophysical data can suggest a funnel geometry, even for large plate-subsidence calderas bounded by ring faults. Simple geometric models indicate that many large calderas have subsided 3-5 km, greater than the depth of most naturally exposed sections of intracaldera deposits. Many ring-fault platesubsidence calderas and intrusive ring complexes have been recognized in the western U.S., Japan, and elsewhere, but no well-documented examples of exposed eroded calderas have large-scale funnel geometry or chaotically disrupted caldera floors. Reported ignimbrite "shields" in the central Andes, where large-volume ash-flows are inferred to

  5. Investigation of correlation of the variations in land subsidence (detected by continuous GPS measurements and methodological data in the surrounding areas of Lake Urmia

    Directory of Open Access Journals (Sweden)

    K. Moghtased-Azar

    2012-11-01

    Full Text Available Lake Urmia, a salt lake in the north-west of Iran, plays a valuable role in the environment, wildlife and economy of Iran and the region, but now faces great challenges for survival. The Lake is in immediate and great danger and is rapidly going to become barren desert. As a result, the increasing demands upon groundwater resources due to expanding metropolitan and agricultural areas are a serious challenge in the surrounding regions of Lake Urmia. The continuous GPS measurements around the lake illustrate significant subsidence rate between 2005 and 2009. The objective of this study was to detect and specify the non-linear correlation of land subsidence and temperature activities in the region from 2005 to 2009. For this purpose, the cross wavelet transform (XWT was carried out between the two types of time series, namely vertical components of GPS measurements and daily temperature time series. The significant common patterns are illustrated in the high period bands from 180–218 days band (~6–7 months from September 2007 to February 2009. Consequently, the satellite altimetry data confirmed that the maximum rate of linear trend of water variation in the lake from 2005 to 2009, is associated with time interval from September 2007 to February 2009. This event was detected by XWT as a critical interval to be holding the strong correlation between the land subsidence phenomena and surface temperature. Eventually the analysis can be used for modeling and prediction purposes and probably stave off the damage from subsidence phenomena.

  6. Sinkholes, subsidence and subrosion on the eastern shore of the Dead Sea as revealed by a close-range photogrammetric survey

    Science.gov (United States)

    Al-Halbouni, Djamil; Holohan, Eoghan P.; Saberi, Leila; Alrshdan, Hussam; Sawarieh, Ali; Closson, Damien; Walter, Thomas R.; Dahm, Torsten

    2017-05-01

    Ground subsidence and sinkhole collapse are phenomena affecting regions of karst geology worldwide. The rapid development of such phenomena around the Dead Sea in the last four decades poses a major geological hazard to the local population, agriculture and industry. Nonetheless many aspects of this hazard are still incompletely described and understood, especially on the eastern Dead Sea shore. In this work, we present a first low altitude (digital surface model (5 cm px-1) and orthophoto of this area (2.1 km2). We also outline the factors affecting the quality and accuracy of this approach. Our analysis reveals a kilometer-scale sinuous depression bound partly by flexure and partly by non-tectonic faults. The estimated minimum volume loss of this subsided zone is 1.83 ṡ 106 m3 with an average subsidence rate of 0.21 m yr-1 over the last 25 years. Sinkholes in the surveyed area are localized mainly within this depression. The sinkholes are commonly elliptically shaped (mean eccentricity 1.31) and clustered (nearest neighbor ratio 0.69). Their morphologies and orientations depend on the type of sediment they form in: in mud, sinkholes have a low depth to diameter ratio (0.14) and a long-axis azimuth of NNE-NE. In alluvium, sinkholes have a higher ratio (0.4) and are orientated NNW-N. From field work, we identify actively evolving artesian springs and channelized, sediment-laden groundwater flows that appear locally in the main depression. Consequently, subrosion, i.e. subsurface mechanical erosion, is identified as a key physical process, in addition to dissolution, behind the subsidence and sinkhole hazard. Furthermore, satellite image analysis links the development of the sinuous depression and sinkhole formation at Ghor Al-Haditha to preferential groundwater flow paths along ancient and current wadi riverbeds.

  7. Land subsidence monitoring and prediction in Beijing based on multi-sensor InSAR and improved Gray-Markov model

    Science.gov (United States)

    Ke, Y.; Deng, Z.; Gong, H.; Guo, L.; Li, X.

    2016-12-01

    Land subsidence induced by excessive groundwater withdrawal has posed a severe threat to city infrastructures, buildings and water and gas pipes, and has caused considerable economic loss. With rapid population increase and the corresponding rising demand for ground water, the land deformation rate has sped up. It was reported that by the end of 2010, over 65% (4281km2) of the plain area in Beijing has suffered ground settlement of over 50mm. Timely monitoring of land subsidence is a prerequisite for understanding of spatiotemporal evolution and the mechanism of the process. Prediction of future land subsidence development assists decision making for prevention of the hazard. In this study, we combined InSAR techniques with an improved Gray-Markov model (GMM) to predict the spatiotemporal trend of ground settlement in Beijing. First, ENVISAT ASAR data from 2003 to 2010 and Radarsat-2 data from 2010 to 2014 were used to monitor land subsidence during the recent 11 years by PS-InSAR technique. Three settlement bowls were demonstrated in the study area and located in Chaoyang, Changping, and Tongzhou districts. The maximum displacement rate reached around 125mm/year and the maximum cumulative deformation reached over 1.3m. For each PS pixels, we developed an improved GMM in order to predict the deformation trend in the next three years. GMM was improved in two aspects. First, we adapted GMM model based on metabolism principle by assigning newer information with higher priority. Second, we applied k-means method to automatically partition the states in Markov chain instead of manually assigning Markov intervals. By applying the improved GMM to PS pixels over the study area, the deformation maps from 2015 to 2017 were generated and it was found that the maximum cumulative deformation will reach 1.6m by the end of 2017.

  8. Employer perspectives on the role of soft skills in subsidized employment relationships

    OpenAIRE

    Camochan, S; S. Taylor; Pascual, G.; Austin, MJ

    2014-01-01

    ©Alliance for Children and Families. The dual objective of subsidized employment programs is to support employers and low-income job seekers. However, few studies of these programs have examined employer perspectives or reflected critically on the role of soft skills in relationships between employers and subsidized employees. This qualitative study examined employer perspectives on soft skills, drawing on the concept of fit from the person-in-environment perspective, as framed by personnel p...

  9. Evaluating Land Subsidence Rates and Their Implications for Land Loss in the Lower Mississippi River Basin

    Directory of Open Access Journals (Sweden)

    Lei Zou

    2015-12-01

    Full Text Available High subsidence rates, along with eustatic sea-level change, sediment accumulation and shoreline erosion have led to widespread land loss and the deterioration of ecosystem health around the Lower Mississippi River Basin (LMRB. A proper evaluation of the spatial pattern of subsidence rates in the LMRB is the key to understanding the mechanisms of the submergence, estimating its potential impacts on land loss and the long-term sustainability of the region. Based on the subsidence rate data derived from benchmark surveys from 1922 to 1995, this paper constructed a subsidence rate surface for the region through the empirical Bayesian kriging (EBK interpolation method. The results show that the subsidence rates in the region ranged from 1.7 to 29 mm/year, with an average rate of 9.4 mm/year. Subsidence rates increased from north to south as the outcome of both regional geophysical conditions and anthropogenic activities. Four areas of high subsidence rates were found, and they are located in Orleans, Jefferson, Terrebonne and Plaquemines parishes. A projection of future landscape loss using the interpolated subsidence rates reveals that areas below zero elevation in the LMRB will increase from 3.86% in 2004 to 19.79% in 2030 and 30.88% in 2050. This translates to a growing increase of areas that are vulnerable to land loss from 44.3 km2/year to 240.7 km2/year from 2011 to 2050. Under the same scenario, Lafourche, Plaquemines and Terrebonne parishes will experience serious loss of wetlands, whereas Orleans and Jefferson parishes will lose significant developed land, and Lafourche parish will endure severe loss of agriculture land.

  10. Wuhan Surface Subsidence Analysis in 2015–2016 Based on Sentinel-1A Data by SBAS-InSAR

    Directory of Open Access Journals (Sweden)

    Lv Zhou

    2017-09-01

    Full Text Available The Terrain Observation with Progressive Scans (TOPS acquisition mode of Sentinel-1A provides a wide coverage per acquisition and features a repeat cycle of 12 days, making this acquisition mode attractive for surface subsidence monitoring. A few studies have analyzed wide-coverage surface subsidence of Wuhan based on Sentinel-1A data. In this study, we investigated wide-area surface subsidence characteristics in Wuhan using 15 Sentinel-1A TOPS Synthetic Aperture Radar (SAR images acquired from 11 April 2015 to 29 April 2016 with the Small Baseline Subset Interferometric SAR (SBAS InSAR technique. The Sentinel-1A SBAS InSAR results were validated by 110 leveling points at an accuracy of 6 mm/year. Based on the verified SBAS InSAR results, prominent uneven subsidence patterns were identified in Wuhan. Specifically, annual average subsidence rates ranged from −82 mm/year to 18 mm/year in Wuhan, and maximum subsidence rate was detected in Houhu areas. Surface subsidence time series presented nonlinear subsidence with pronounced seasonal variations. Comparative analysis of surface subsidence and influencing factors (i.e., urban construction, precipitation, industrial development, carbonate karstification and water level changes in Yangtze River indicated a relatively high spatial correlation between locations of subsidence bowl and those of engineering construction and industrial areas. Seasonal variations in subsidence were correlated with water level changes and precipitation. Surface subsidence in Wuhan was mainly attributed to anthropogenic activities, compressibility of soil layer, carbonate karstification, and groundwater overexploitation. Finally, the spatial-temporal characteristics of wide-area surface subsidence and the relationship between surface subsidence and influencing factors in Wuhan were determined.

  11. Radiographic Subsidence in Asymptomatic Patients After THR Using the Furlong Active HAP Stem.

    Science.gov (United States)

    Cordero-Ampuero, José; Peñalver, Pablo; Antón, Rodrigo; Galán, María; Cordero, Enrique

    2013-07-01

    The short, tapered, collarless Furlong Active stem has been recently associated in the published literature with significant subsidence using Roentgen stereophotogrammetric analysis. The purpose of this study was to analyze the short-term radiographic subsidence in Furlong Active HAP stems and correlate the results with the age, gender, bone morphology, and bone quality of the proximal femur, stem diameter, and medullary canal filling. Sixty-five consecutive patients (70 hips) receiving the Furlong Active HAP stems were enrolled in this prospective series. The average follow-up was 2.99 ± 1.38 years. All patients were evaluated clinically using the Harris Hip Score (HHS) and radiographically for femoral stem subsidence. In addition, proximal femoral osteopenia, proximal femur morphology, and medullary canal filling were also evaluated. The average subsidence was 2.4 mm (from 0 to 13 mm) at the end of the follow-up period. The average HHS score at the end of follow-up was 90 (range, 81-98). There was one intraoperative fracture. Of the Furlong Active stems 61% subsided with initial weight bearing. Subsidence is higher in males, but no correlation has been found with age, stem diameter, morphology, osteopenia, or canal filling.

  12. GIS-based Analysis of LS Factor under Coal Mining Subsidence Impacts in Sandy Region

    Directory of Open Access Journals (Sweden)

    W. Xiao

    2014-09-01

    Full Text Available Coal deposits in the adjacent regions of Shanxi, Shaanxi, and Inner Mongolia province (SSI account for approximately two-thirds of coal in China; therefore, the SSI region has become the frontier of coal mining and its westward movement. Numerous adverse impacts to land and environment have arisen in these sandy, arid, and ecologically fragile areas. Underground coal mining activities cause land to subside and subsequent soil erosion, with slope length and slope steepness (LS as the key influential factor. In this investigation, an SSI mining site was chosen as a case study area, and 1 the pre-mining LS factor was obtained using a digital elevation model (DEM dataset; 2 a mining subsidence prediction was implemented with revised subsidence prediction factors; and 3 the post-mining LS factor was calculated by integrating the pre-mining DEM dataset and coal mining subsidence prediction data. The results revealed that the LS factor leads to some changes in the bottom of subsidence basin and considerable alterations at the basin’s edges of basin. Moreover, the LS factor became larger in the steeper terrain under subsidence impacts. This integrated method could quantitatively analyse LS changes and spatial distribution under mining impacts, which will benefit and provide references for soil erosion evaluations in this region

  13. Resistance to subsidence of an uncemented femoral stem after cerclage wiring of a fissure.

    Science.gov (United States)

    McCulloch, Ryan S; Roe, Simon C; Marcellin-Little, Denis J; Mente, Peter L

    2012-01-01

    To compare: (1) the force required to initiate subsidence, and (2) the relative subsidence, of femoral stems implanted into intact femora, and then into the same femora in which an induced fissure had been stabilized by cerclage. In vitro, mechanical study. Femora (n=9) from 9 dogs. Femora were prepared for implantation of an uncemented stem. Stems were implanted with continuous and impact loading. After axial loading until a fissure occurred, the stems were extracted, and the fissure stabilized with double-loop cerclage. Stems were reimplanted, and reloaded to failure. Mean±SD load to initiate subsidence in intact femora was 1706±584 N compared with 2379±657 N for cerclaged bones (P=.002). Mean relative subsidence of intact femora was 3.99±2.09 mm compared with 1.79±2.99 mm for cerclaged bones (P=.091). The load to initiate subsidence is increased in femora that have fissured, then have been stabilized with double-loop cerclage, when compared with intact femora. The relative subsidence is not different between intact and stabilized specimens. © Copyright 2011 by The American College of Veterinary Surgeons.

  14. Real-time monitoring of seismicity and deformation during the Bárdarbunga rifting event and associated caldera subsidence

    Science.gov (United States)

    Jónsdóttir, Kristín; Ófeigsson, Benedikt; Vogfjörd, Kristín; Roberts, Matthew; Barsotti, Sara; Gudmundsson, Gunnar; Hensch, Martin; Bergsson, Bergur; Kjartansson, vilhjálmur; Erlendsson, Pálmi; Friðriksdóttir, Hildur; Hreinsdóttir, Sigrún; Guðmundsson, Magnús; Sigmundsson, Freysteinn; Árnadóttir, Thóra; Heimisson, Elías; Hjorleifsdóttir, Vala; Soring, Jón; Björnsson, Bogi; Oddsson, Björn

    2015-04-01

    data and models based on remote sensing were presented, further supporting the interpretations of lateral movements of magma. The rapid evolution of the dyke called for a quick response to install new seismic and GPS stations to improve constraints for the intrusion (seismic locations and deformation). The subsidence of the caldera called for innovative thinking, resulting in a high-rate cGPS instrument together with a strong motion sensor being installed on the ice surface. Moreover, specially designed broadband glacier seismometers have been installed. Surveillance flights continue to be carried out to monitor ice surface changes and provide important data on caldera deformation. Monitoring information and interpretations of geophysical data have been made accessible to the public. Automated and manually checked earthquake locations are presented on web based maps and updated every five minutes. In addition cGPS time-series and maps showing GPS deformation vectors together with the color coded temporal evolution of the earthquake sequence are presented and updated regularly on IMO's webpage. Several examples of near-real-time data transfer, analysis and online visualization will be presented.

  15. On Assessment and Estimation of Potential Losses due to Land Subsidence in Urban Areas of Indonesia

    Science.gov (United States)

    Abidin, Hasanuddin Z.; Andreas, Heri; Gumilar, Irwan; Sidiq, Teguh P.

    2016-04-01

    Land subsidence is natural-anthropogenic hazard affecting several large urban areas in Indonesia, i.e. Jakarta, Bandung and Semarang. Geodetic based results from various techniques (e.g. Leveling, GPS and InSAR) show that land subsidence rates in all three cities generally have spatial and temporal variations, and their magnitude is in average about 5-10 cm/year. The impacts of subsidence in those cities can be seen in the field in various forms such as cracking of permanent constructions and roads, tilting of houses and buildings, 'sinking' of houses and buildings, changes in river canal and drain flow systems, wider expansion of coastal and/or inland flooding areas, and increased inland sea water intrusion. These impacts can be categorized into infrastructure, environmental, economic, and social impacts. The potential losses due to land subsidence in urban areas are actually quite significant. Related infrastructural, social and environmental costs due to direct and indirect impacts of land subsidence are economically quite significant, and can not be underestimated in sustainable urban development. The planning, development and maintenance costs of building and infrastructures in the affected areas are usually much higher than the normal situation. The collateral impact of coastal subsidence in Jakarta and Semarang, in the form of coastal flooding during high tides is also quite damaging. This repeated coastal flooding in several areas along the coast will deteriorate the structure and function of building and infrastructures, badly influences the quality of the living environment and life (e.g. health and sanitation condition), and also disrupts economic and social activities in the affected areas. As in the case of Bandung, inland subsidence also has a quite significant impact on inland flooding phenomena, since it will theoretically lead to expanded coverage and deeper water depth of flooded (inundated) areas. Since the direct and indirect impacts of

  16. La subsidence dans le Viking Graben (mer du Nord septentrionale Subsidence in the Viking Graben (Northern Part of the North Sea

    Directory of Open Access Journals (Sweden)

    Vially R.

    2006-11-01

    Full Text Available L'utilisation des modèles numériques de calcul de la subsidence nécessite une bonne connaissance géologique de la zone étudiée. Seule une étude détaillée de stratigraphie sismique le long de profils régionaux passant par des forages permet de contraindre les différents paramètres servant au calcul de la subsidence. L'étude de la subsidence du Viking Graben a mis en évidence trois épisodes : - phase de distension permo-triasique (saalienne ? dont l'axe de subsidence est décalé vers l'est par rapport à l'axe actuel du Viking Graben; - phase de distension jurassique supérieur (cimmérienne qui crée les structures majeures de cette zone; - phase paléocène correspondant au contrecoup de l'ouverture plus à l'ouest de l'Atlantique Nord. Cette phase est surtout sensible à l'ouest de la zone étudiée. Les cartes de subsidence pour les différentes époques font apparaître l'influence du bati calédonien. Deux directions principales apparaissent, une NE-SW correspondant aux directions structurales visibles à terre en Ecosse et une NW-SE discrète qui sépare le Southern Viking Graben du Northern Viking Graben. Cette dernière direction pourrait se calquer sur la suture (au Silurien d'un diverticule de l'océan lapétus, la Tornquist Sea. The use of numerical models for computing subsidence requires a good geological understanding of the zone being examined. Detailed seismic stratigraphy along regional profiles going via boreholes is the only way to determine the different parameters required for computing subsidence. An investigation of the subsidence of the Viking Graben in the North Sea has revealed three episodes:(a The Permo-Triassic (Saalian ? distension phase during which the axis of subsidence lay to the east of the present axis of the Viking Graben. (b The later Jurassic (Kimmerian distension phase which created the major structures in this zone. (c The Paleocene phase corresponding to the backlash of the westward

  17. Quaternary sedimentation and subsidence history of Lake Baikal, Siberia, based on seismic stratigraphy and coring

    Science.gov (United States)

    Colman, Steven M.; Karabanov, E.B.; Nelson, C. H.

    2003-01-01

    The long, continuous, high-latitude, stratigraphic record of Lake Baikal was deposited in three broad sedimentary environments, defined by high-resolution seismic-reflection and coring methods: (1) turbidite depositional systems, by far the most widespread, characterizing most of the margins and floors of the main basins of the lake, (2) large deltas of major drainages, and (3) tectonically or topographically isolated ridges and banks. Holocene sedimentation rates based on radiocarbon ages vary by more than an order of magnitude among these environments, from less than about 0.03 mm/yr on ridges and banks to more than about 0.3 mm/yr on basin floors. Extrapolating these rates, with a correction for compaction, yields tentative estimates of about 25 and 11 Ma for the inception of rifting in the Central and North basins, respectively, and less than 6 Ma for the 200-m sediment depth on Academician Ridge. The Selenga Delta has the distinctive form of a classic prograding Gilbert-type delta, but its history appears to represent a complex combination of tectonism and sedimentation. The central part of the delta is underlain by prograding, shallow-water sequences, now several hundred meters below the lake surface. These deposits and much of the delta slope are mantled by fine-grained, deep-water, hemipelagic deposits whose base is estimated to be about 650,000 years old. Modern coarse-grained sediment bypasses the delta slope through fault-controlled canyons that feed large, subaqueous fans at the ends of the South and Central basins. These relations, along with abundant other evidence of recent faulting and the great depths of the Central and South basins, suggest that these two rift basins have experienced a period of unusually rapid subsidence over the last 650,000 years, during at least part of which sedimentation has failed to keep pace.

  18. Surface Subsidence Analysis by Multi-Temporal InSAR and GRACE: A Case Study in Beijing

    Science.gov (United States)

    Guo, Jiming; Zhou, Lv; Yao, Chaolong; Hu, Jiyuan

    2016-01-01

    The aim of this study was to investigate the relationship between surface subsidence and groundwater changes. To investigate this relationship, we first analyzed surface subsidence. This paper presents the results of a case study of surface subsidence in Beijing from 1 August 2007 to 29 September 2010. The Multi-temporal Interferometric Synthetic Aperture Radar (multi-temporal InSAR) technique, which can simultaneously detect point-like stable reflectors (PSs) and distributed scatterers (DSs), was used to retrieve the subsidence magnitude and distribution in Beijing using 18 ENVISAT ASAR images. The multi-temporal InSAR-derived subsidence was verified by leveling at an accuracy better than 5 mm/year. Based on the verified multi-temporal InSAR results, a prominent uneven subsidence was identified in Beijing. Specifically, most of the subsidence velocities in the downtown area were within 10 mm/year, and the largest subsidence was detected in Tongzhou, with velocities exceeding 140 mm/year. Furthermore, Gravity Recovery and Climate Experiment (GRACE) data were used to derive the groundwater change series and trend. By comparison with the multi-temporal InSAR-derived subsidence results, the long-term decreasing trend between groundwater changes and surface subsidence showed a relatively high consistency, and a significant impact of groundwater changes on the surface subsidence was identified. Additionally, the spatial distribution of the subsidence funnel was partially consistent with that of groundwater depression, i.e., the former possessed a wider range than the latter. Finally, the relationship between surface subsidence and groundwater changes was determined. PMID:27649183

  19. Water availability and land subsidence in the Central Valley, California, USA

    Science.gov (United States)

    Faunt, Claudia C.; Sneed, Michelle; Traum, Jon; Brandt, Justin T.

    2016-05-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007-2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  20. Spatial prediction of ground subsidence susceptibility using an artificial neural network.

    Science.gov (United States)

    Lee, Saro; Park, Inhye; Choi, Jong-Kuk

    2012-02-01

    Ground subsidence in abandoned underground coal mine areas can result in loss of life and property. We analyzed ground subsidence susceptibility (GSS) around abandoned coal mines in Jeong-am, Gangwon-do, South Korea, using artificial neural network (ANN) and geographic information system approaches. Spatial data of subsidence area, topography, and geology, as well as various ground-engineering data, were collected and used to create a raster database of relevant factors for a GSS map. Eight major factors causing ground subsidence were extracted from the existing ground subsidence area: slope, depth of coal mine, distance from pit, groundwater depth, rock-mass rating, distance from fault, geology, and land use. Areas of ground subsidence were randomly divided into a training set to analyze GSS using the ANN and a test set to validate the predicted GSS map. Weights of each factor's relative importance were determined by the back-propagation training algorithms and applied to the input factor. The GSS was then calculated using the weights, and GSS maps were created. The process was repeated ten times to check the stability of analysis model using a different training data set. The map was validated using area-under-the-curve analysis with the ground subsidence areas that had not been used to train the model. The validation showed prediction accuracies between 94.84 and 95.98%, representing overall satisfactory agreement. Among the input factors, "distance from fault" had the highest average weight (i.e., 1.5477), indicating that this factor was most important. The generated maps can be used to estimate hazards to people, property, and existing infrastructure, such as the transportation network, and as part of land-use and infrastructure planning.

  1. Investigation of Land Subsidence using ALOS PALSAR data: a case study in Mentougou (Beijing, China)

    Science.gov (United States)

    Chen, Jianping; Xiang, Jie; Xie, Shuai; Liu, Jing; Tarolli, Paolo

    2017-04-01

    Mining activities have been documented for centuries in Mentougou, and land subsidence resulting from mining operations has already been known over the past few decades. However, there has been ongoing concern that excessive groundwater extraction may lead to further subsidence. Therefore it is critical to map the land cover changes to understand the actual impact of these activities. So, the land cover changes from 2006 to 2011 were examined based on multi-source remote sensing imageries( including ALOS and landsat-7) by using object-oriented classifications combined with a decision tree and retrospective approaches. Also, land subsidence in Mentougou between 2006 and 2011 has been mapped using the interferometric synthetic aperture radar (InSAR) time-series analysis with the ALOS L-band SAR data. We processed 14 ascending SAR images during May 2006 to July 2011. Comparison of InSAR measurements with the land cover changes and pre-existing faults suggest that mining activities is the main cause of land subsidence. The land subsidence observed from InSAR data are approximately up to 15 mm/year in open-pit mining area and up to 24 mm/year in underground mining areas. The InSAR result are validated by the ground survey data in several areas, and the comparison between the InSAR result with the mining schedule showed there were some correlations between them. The result underline the potential use of InSAR measurements to provide better investigation for land subsidence, and also suggest that the most influential factors for land subsidence is underground coal mine.

  2. Fragmentary evidence of great-earthquake subsidence during holocene emergence, Valdivia estuary, South Central Chile

    Science.gov (United States)

    Nelson, A.R.; Kashima, K.; Bradley, L.-A.

    2009-01-01

    A reconnaissance of Holocene stratigraphy beneath fringing marshes of the Valdivia estuary, where an M 9.5 earthquake caused 1-2 m of regional coseismic subsidence in 1960, shows only fragmentary evidence of prehistoric coseismic subsidence. In most of the 150 hand-driven cores that were examined, a distinct unconformity separates 0.5-1.5 m of late Holocene tidal and floodplain mud, peat, and sand from underlying middle Holocene subtidal mud and sand. At the Las Coloradas site, where stratigraphy is best preserved, two A horizons of marsh and meadow soils abruptly overlain by sand and mud probably record coseismic subsidence shortly followed by tsunamis. The amount of subsidence during the earthquakes proved difficult to reconstruct with a diatom transfer function because of differences between modern and fossil diatom assemblages. Maximum 14C ages on macrofossils from the two A horizons at the Las Coloradas site of 1.7-1.3 ka and 2.7-1.7 ka allow correlation of the younger horizon with either of two of six 14C-dated A horizons buried by tsunami sand or post-tsunami tidal sand 200 km to the south at Maull??n, and with a lake-wide mass wasting event in Lago Puyehue, 100 km to the southeast. Tidal records of prehistoric coseismic subsidence at Valdivia are scarce because of a sea-level fall of 3-8 m over the past 6000 years, erosion of marsh and meadow soils during subsidence-induced flooding of the estuary, and largely complete land-level recovery during cycles of coseismic subsidence and postseismic uplift.

  3. Subsidence monitoring with geotechnical instruments in the Mexicali Valley, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    E. Glowacka

    2015-11-01

    Full Text Available The Mexicali Valley (northwestern Mexico, situated in the southern part of the San Andreas fault system, is an area with high tectonic deformation, recent volcanism, and active seismicity. Since 1973, fluid extraction, from the 1500–3000 m depth range, at the Cerro Prieto Geothermal Field (CPGF, has influenced deformation in the Mexicali Valley area, accelerating the subsidence and causing slip along the traces of tectonic faults that limit the subsidence area. Detailed field mapping done since 1989 (González et al., 1998; Glowacka et al., 2005; Suárez-Vidal et al., 2008 in the vicinity of the CPGF shows that many subsidence induced fractures, fissures, collapse features, small grabens, and fresh scarps are related to the known tectonic faults. Subsidence and fault rupture are causing damage to infrastructure, such as roads, railroad tracks, irrigation channels, and agricultural fields. Since 1996, geotechnical instruments installed by CICESE (Centro de Investigación Ciéntifica y de Educación Superior de Ensenada, B.C. have operated in the Mexicali Valley, for continuous recording of deformation phenomena. Instruments are installed over or very close to the affected faults. To date, the network includes four crackmeters and eight tiltmeters; all instruments have sampling intervals in the 1 to 20 min range. Instrumental records typically show continuous creep, episodic slip events related mainly to the subsidence process, and coseismic slip discontinuities (Glowacka et al., 1999, 2005, 2010; Sarychikhina et al., 2015. The area has also been monitored by levelling surveys every few years and, since the 1990's by studies based on DInSAR data (Carnec and Fabriol, 1999; Hansen, 2001; Sarychikhina et al., 2011. In this work we use data from levelling, DInSAR, and geotechnical instruments records to compare the subsidence caused by anthropogenic activity and/or seismicity with slip recorded by geotechnical instruments, in an attempt to obtain

  4. Subsidence monitoring with geotechnical instruments in the Mexicali Valley, Baja California, Mexico

    Science.gov (United States)

    Glowacka, E.; Sarychikhina, O.; Márquez Ramírez, V. H.; Robles, B.; Nava, F. A.; Farfán, F.; García Arthur, M. A.

    2015-11-01

    The Mexicali Valley (northwestern Mexico), situated in the southern part of the San Andreas fault system, is an area with high tectonic deformation, recent volcanism, and active seismicity. Since 1973, fluid extraction, from the 1500-3000 m depth range, at the Cerro Prieto Geothermal Field (CPGF), has influenced deformation in the Mexicali Valley area, accelerating the subsidence and causing slip along the traces of tectonic faults that limit the subsidence area. Detailed field mapping done since 1989 (González et al., 1998; Glowacka et al., 2005; Suárez-Vidal et al., 2008) in the vicinity of the CPGF shows that many subsidence induced fractures, fissures, collapse features, small grabens, and fresh scarps are related to the known tectonic faults. Subsidence and fault rupture are causing damage to infrastructure, such as roads, railroad tracks, irrigation channels, and agricultural fields. Since 1996, geotechnical instruments installed by CICESE (Centro de Investigación Ciéntifica y de Educación Superior de Ensenada, B.C.) have operated in the Mexicali Valley, for continuous recording of deformation phenomena. Instruments are installed over or very close to the affected faults. To date, the network includes four crackmeters and eight tiltmeters; all instruments have sampling intervals in the 1 to 20 min range. Instrumental records typically show continuous creep, episodic slip events related mainly to the subsidence process, and coseismic slip discontinuities (Glowacka et al., 1999, 2005, 2010; Sarychikhina et al., 2015). The area has also been monitored by levelling surveys every few years and, since the 1990's by studies based on DInSAR data (Carnec and Fabriol, 1999; Hansen, 2001; Sarychikhina et al., 2011). In this work we use data from levelling, DInSAR, and geotechnical instruments records to compare the subsidence caused by anthropogenic activity and/or seismicity with slip recorded by geotechnical instruments, in an attempt to obtain more information

  5. Effects of cavern depth on surface subsidence and storage loss of oil-filled caverns

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E L

    1992-01-01

    Finite element analyses of oil-filled caverns were performed to investigate the effects of cavern depth on surface subsidence and storage loss, a primary performance criteria of SPR caverns. The finite element model used for this study was axisymmetric, approximating an infinite array of caverns spaced at 750 ft. The stratigraphy and cavern size were held constant while the cavern depth was varied between 1500 ft and 3000 ft in 500 ft increments. Thirty year simulations, the design life of the typical SPR cavern, were performed with boundary conditions modeling the oil pressure head applied to the cavern lining. A depth dependent temperature gradient of 0.012{degrees}F/ft was also applied to the model. The calculations were performed using ABAQUS, a general purpose of finite element analysis code. The user-defined subroutine option in ABAQUS was used to enter an elastic secondary creep model which includes temperature dependence. The calculations demonstrated that surface subsidence and storage loss rates increase with increasing depth. At lower depths the difference between the lithostatic stress and the oil pressure is greater. Thus, the effective stresses are greater, resulting in higher creep rates. Furthermore, at greater depths the cavern temperatures are higher which also produce higher creep rates. Together, these factors result in faster closure of the cavern. At the end of the 30 year simulations, a 1500 ft-deep cavern exhibited 4 percent storage loss and 4 ft of subsidence while a 3000 ft-deep cavern exhibited 33 percent storage loss and 44 ft of subsidence. The calculations also demonstrated that surface subsidence is directly related to the amount of storage loss. Deeper caverns exhibit more subsidence because the caverns exhibit more storage loss. However, for a given amount of storage loss, nearly the same magnitude of surface subsidence was exhibited, independent of cavern depth.

  6. Water availability and land subsidence in the Central Valley, California, USA

    Science.gov (United States)

    Faunt, Claudia; Sneed, Michelle; Traum, Jonathan A.; Brandt, Justin

    2016-01-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007–2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  7. Should bus commuting be subsidized for providing quality transport ...

    Indian Academy of Sciences (India)

    Urban transport has serious problems that are symptoms of the general process of rapid urbanization and environmental degradation. Policymakers in general and urban economists in particular have paid little attention to public transport system pricing leading to the absence of a financially viable, self-supporting urban ...

  8. Coastal Flood Risks in the Bangkok Metropolitan Region, Thailand: Combined Impacts of Land Subsidence, Sea Level Rise and Storm Surge

    Science.gov (United States)

    Duangyiwa, C.; Yu, D.; Wilby, R.; Aobpaet, A.

    2015-12-01

    Due to the fast-changing climatic and anthropogenic conditions at coastal regions, many coastal mega-cities are becoming increasingly vulnerable to internal and external risks. The risk is particularly high for low-lying coastal cities in developing nations, with Southeast Asia recognized as a hotspot of vulnerability due to the increasing population density, rapid change of natural landscape associated with urbanization and intensified hydrological and atmospheric conditions at the coastal front in an uncertain climate future. The Bangkok Metropolitan Region is one of the largest coastal megacities in Southeast Asia that are challenged by the potential impacts due to climate change and anthropological variability in the coming decades. Climate-related risks in this region are associated with its relatively low-lying nature of the terrain and adjacency to the coast. Coastal inundation due to high tides from the sea occurs annually in the area close to the seashore. This is set to increase given a projected rising sea level and the sinking landscape due to groundwater extraction and urbanization. The aim of this research is, therefore, to evaluate the vulnerability of the city to sea level rise, land subsidence and storm surge. Distributed land subsidence rate, projected sea level rise and existing structural features such as flood defences are taken into account. The 2011 flood in Thailand is used as a baseline event. Scenarios were designed with projections of land subsidence and sea level rise to 2050s, 2080s, and 2100s. A two-dimensional flood inundation model (FloodMap, Yu and Lane 2006) is used to derive inundation depth and velocity associated with each scenario. The impacts of coastal flood risk on critical infrastructures (e.g. power supply, transportation network, rescue centers, hospitals, schools and key government buildings) are evaluated (e.g. Figure 1). Results suggest progressively increase but non-linear risks of coastal flooding to key coastal

  9. Long term peatland subsidence: Experimental study and modeling scenarios in the Venice coastland

    Science.gov (United States)

    Zanello, Francesca; Teatini, Pietro; Putti, Mario; Gambolati, Giuseppe

    2011-12-01

    Land subsidence in drained cultivated peatlands is responsible for a number of serious environmental concerns and economical problems at both the local and the global scale. In low-lying coastal areas it enhances the risk of flooding, the saltwater contamination of shallow aquifers, and the maintenance costs of the systems that help keep the farmland drained. Since the subsidence is a major consequence of the bio-oxidation of the soil organic fraction in the upper aerated zone, cropped peatlands in temperate and tropic regions are important sources of CO2 into the atmosphere. A 4-year long experimental study has been performed in a drained peatland located south of the Venice Lagoon, Italy, to help calibrate a land subsidence model developed to predict the expected behavior of the ground surface elevation. Continuous monitoring of the hydrological regime and land displacements shows that the vertical movement of the peat surface consists of the superimposition of daily/seasonal time-scale reversible deformations related to soil moisture, depth to the water table, and temperature fluctuations, and long term irreversible subsidence due to peat oxidation. A novel two-step modeling approach to separate the two contributions from the available observations is presented. First, the elastic component is computed by integrating the peat vertical deformations evaluated by a constitutive relationship describing the porosity variation with the moisture content and pore pressure changes implemented into a variably saturated flow equation-based numerical code. The observed trend is then filtered from the computed reversible displacement and is used to calibrate an empirical relationship relating land subsidence rate to drainage depth and soil temperature. The results show that in recent years the subsidence rate ranged from 3 to 15 mm a-1. The large variability is due to the different climate conditions underlying the monitoring period, in particular a wet 2002 and a very dry

  10. Subsidence Induced Faulting Hazard risk maps in Mexico City and Morelia, central Mexico

    Science.gov (United States)

    Cabral-Cano, E.; Solano-Rojas, D.; Hernández-Espriu, J.; Cigna, F.; Wdowinski, S.; Osmanoglu, B.; Falorni, G.; Bohane, A.; Colombo, D.

    2012-12-01

    Subsidence and surface faulting have affected urban areas in Central Mexico for decades and the process has intensified as a consequence of urban sprawl and economic growth. This process causes substantial damages to the urban infrastructure and housing structures and in several cities it is becoming a major factor to be considered when planning urban development, land use zoning and hazard mitigation strategies in the next decades. Subsidence is usually associated with aggressive groundwater extraction rates and a general decrease of aquifer static level that promotes soil consolidation, deformation and ultimately, surface faulting. However, local stratigraphic and structural conditions also play an important role in the development and extension of faults. Despite its potential for damaging housing, and other urban infrastructure, the economic impact of this phenomena is poorly known, in part because detailed, city-wide subsidence induced faulting risk maps have not been published before. Nevertheless, modern remote sensing techniques are most suitable for this task. We present the results of a risk analysis for subsidence induced surface faulting in two cities in central Mexico: Morelia and Mexico City. Our analysis in Mexico City and Morelia is based on a risk matrix using the horizontal subsidence gradient from a Persistent Scatterer InSAR (Morelia) and SqueeSAR (Mexico City) analysis and 2010 census population distribution data from Mexico's National Institute of Statistics and Geography. Defining subsidence induced surface faulting vulnerability within these urbanized areas is best determined using both magnitude and horizontal subsidence gradient. Our Morelia analysis (597,000 inhabitants with localized subsidence rates up to 80 mm/yr) shows that 7% of the urbanized area is under a high to very high risk level, and 14% of its population (11.7% and 2.3% respectively) lives within these areas. In the case of the Mexico City (15'490,000 inhabitants for the

  11. Pengaruh Land Subsidence terhadap Genangan Banjir dan Rob di Semarang Timur

    Directory of Open Access Journals (Sweden)

    ratih Pujiastuti

    2016-06-01

    Full Text Available Inundation of flood and rob (flood due to high tides in Semarang City is increase wtithin area and depth. It be more seroius condition because of land subsisdence that happened in coastal area of Semarang City. This research is foccused on prediction and mapping of inundation flood and rob due to land subsidence effect in East Semarang, especially Tenggang Watershed and Sringin Watershed. On this research, data analysis including analysis of land subsidence, analysis of hydrological data, analysis of flood discharge with HEC-HMS, hydraulics analysis with HEC-RAS and then mapping the results of the flood inundation with Arc GIS. The inundation will be create with overlay the DEM of flood water level and DEM of topographic. According to the results of analysis is known that minimum land subsidence is 0 cm/year that happened in south area of Semarang and more higher ini north area with maximum land subsidence is 5.58 cm/year. On periode   2014-2031, the contribute of land subsidence to increase the inundation of flood and rob is 1.39%/year.

  12. Land subsidence in the southwestern Mojave Desert, California, 1992–2009

    Science.gov (United States)

    Brandt, Justin; Sneed, Michelle

    2017-07-19

    Groundwater has been the primary source of domestic, agricultural, and municipal water supplies in the southwestern Mojave Desert, California, since the early 1900s. Increased demands on water supplies have caused groundwater-level declines of more than 100 feet (ft) in some areas of this desert between the 1950s and the 1990s (Stamos and others, 2001; Sneed and others, 2003). These water-level declines have caused the aquifer system to compact, resulting in land subsidence. Differential land subsidence (subsidence occurring at different rates across the landscape) can alter surface drainage routes and damage surface and subsurface infrastructure. For example, fissuring across State Route 247 at Lucerne Lake has required repairs as has pipeline infrastructure near Troy Lake.Land subsidence within the Mojave River and Morongo Groundwater Basins of the southwestern Mojave Desert has been evaluated using InSAR, ground-based measurements, geology, and analyses of water levels between 1992 and 2009 (years in which InSAR data were collected). The results of the analyses were published in three USGS reports— Sneed and others (2003), Stamos and others (2007), and Solt and Sneed (2014). Results from the latter two reports were integrated with results from other USGS/ MWA cooperative groundwater studies into the broader scoped USGS Mojave Groundwater Resources Web site (http://ca.water.usgs.gov/ mojave/). This fact sheet combines the detailed analyses from the three subsidence reports, distills them into a longer-term context, and provides an assessment of options for future monitoring.

  13. Effects of Active Subsidence Vs. Existing Basin Geometry on Fluviodeltaic Channels and Stratal Architecture

    Science.gov (United States)

    Liang, M.; Kim, W.; Passalacqua, P.

    2015-12-01

    Tectonic subsidence and basin topography, both determining the accommodation, are fundamental controls on the basin filling processes. Their effects on the fluvial organization and the resultant subsurface patterns remain difficult to predict due to the lack of understanding about interaction between internal dynamics and external controls. Despite the intensive studies on tectonic steering effects on alluvial architecture, how the self-organization of deltaic channels, especially the distributary channel network, respond to tectonics and basin geometry is mostly unknown. Recently physical experiments and field studies have hinted dramatic differences in fluviodeltaic evolution between ones associated with active differential subsidence and existing basin depth. In this work we designed a series of numerical experiments using a reduced-complexity channel-resolving model for delta formation, and tested over a range of localized subsidence rates and topographic depression in basin geometry. We also used a set of robust delta metrics to analyze: i) shoreline planform asymmetry, ii) channel and lobe geometry, iii) channel network pattern, iv) autogenic timescales, and v) subsurface structure. The modeling results show that given a similar final thickness, active subsidence enhances channel branching with smaller channel sand bodies that are both laterally and vertically connected, whereas existing topographic depression causes more large-scale channel avulsions with larger channel sand bodies. In general, both subsidence and existing basin geometry could steer channels and/or lock channels in place but develop distinct channel patterns and thus stratal architecture.

  14. Consolidation and shear failure leading to subsidence and settlement. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Abeele, W.; Nyhan, J.W.; Hakonson, T.E.; Drennon, B.J.; Lopez, E.A.; Herrera, W.J.; Langhorst, G.J.; Martinez, J.L.; Trujillo, G.

    1986-02-01

    Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. We have also investigated the shear failure characteristics of crushed tuff that may lead to subsidence. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bentonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. We finally discuss our field experiment, which studies the influence of subsidence on layered systems in general and on biobarriers in particular. The share of the produced cavities is compared with cavities produced by idealized voids in an idealized environment. Study of root penetration at subsidence sites gives us an indication of the remaining degree of integrity. 30 refs., 24 figs., 19 tabs.

  15. Geomechanics of subsidence above single and multi-seam coal mining

    Directory of Open Access Journals (Sweden)

    A.M. Suchowerska Iwanec

    2016-06-01

    Full Text Available Accurate prediction of surface subsidence due to the extraction of underground coal seams is a significant challenge in geotechnical engineering. This task is further compounded by the growing trend for coal to be extracted from seams either above or below previously extracted coal seams, a practice known as multi-seam mining. In order to accurately predict the subsidence above single and multi-seam longwall panels using numerical methods, constitutive laws need to appropriately represent the mechanical behaviour of coal measure strata. The choice of the most appropriate model is not always straightforward. This paper compares predictions of surface subsidence obtained using the finite element method, considering a range of well-known constitutive models. The results show that more sophisticated and numerically taxing constitutive laws do not necessarily lead to more accurate predictions of subsidence when compared to field measurements. The advantages and limitations of using each particular constitutive law are discussed. A comparison of the numerical predictions and field measurements of surface subsidence is also provided.

  16. Neogene residual subsidence and its response to a sinking slab in the deep mantle of eastern China

    Science.gov (United States)

    Yao, Xiang; Liu, ShaoFeng; Bai, Yu; Ji, HuiLi

    2017-08-01

    Mantle convection could have a significant effect on basin evolution; however, research quantifying this relationship is controversial. To understand the formation mechanism and evolution of the Cenozoic rift basins in eastern China, we applied the back-stripping technique and strain rate inversion modeling to 119 wells from Sangjiang Basin, Bohai Bay Basin, North Yellow Sea Basin, South Yellow Sea Basin, East China Sea Shelf Basin, and four basins within the northern South China Sea margin. The modeled results can be used to reconstruct the tectonic subsidence history and further assess the potential subsidence mechanisms of eastern China. Residual subsidence is defined as the difference between the theoretical and observed tectonic subsidences. Our results show that the residual subsidence since 20 Ma in eastern China generally increases from ∼100 to 300 m in terrestrial areas to ∼1.2-1.8 km on the continental shelf. Our observed residual subsidence is generally consistent with the present-day dynamic topography that is predicted from mantle flow models, and it is associated with a stagnant slab within the mantle that has been observed by seismic tomography. The migration pathway of the residual subsidence since 20 Ma is consistent with the movement direction of the Pacific and Philippine plates. Therefore, we suggest that the residual subsidence might be a dynamic subsidence induced by a negative buoyancy of the sinking slab in the deep mantle beneath eastern China.

  17. Review: Water-rock interactions and related eco-environmental effects in typical land subsidence zones of China

    Science.gov (United States)

    Ma, Teng; Du, Yao; Ma, Rui; Xiao, Cong; Liu, Yanjun

    2018-01-01

    Land subsidence is common in some regions of China. Various eco-environmental problems have arisen due to changes in water-rock interactions in these subsided areas, for which a comprehensive understanding of the hydrogeological setting is needed. This paper presents the general status of land subsidence in three typical subsided areas of China through the compilation of relevant data, and reviews some typical changes in the water-rock interactions in subsided areas along with related eco-environmental issues. It is found that the subsidence development and distribution are controlled by the groundwater-withdrawal intensity externally, and by the thickness and compressibility of unconsolidated sediments internally. The physical changes and related effects of water-rock interactions in subsided areas include: (1) the decreased ground elevation that caused floods, waterlogged farmland, etc.; (2) the differential subsidence that caused ground fissures; and (3) the change of seepage field that caused substantial reduction of the water resource. Chemically, the changes and related effects of water-rock interactions include: (1) the change to the chemical environment or processes due to the hydrogeologic structure alteration, which caused groundwater pollution; and (2) hydrologic mixing (seawater intrusion, artificial recharge; exchange with adjacent aquifers or aquitards), which degraded the groundwater quality. Further research on the subsided areas in China is suggested to reveal the mechanisms regarding biological and gaseous (meteorological) changes from the perspective of interacting systems among water, rocks, biological agents and gases.

  18. The East West binary and the burden of representation.

    OpenAIRE

    Burt, Ramsay, 1953-

    2012-01-01

    paper presented at Gdansk Dance Conference, "Asia and Europe – cross-cultural dialogues in theatre and dance” June 18th 2012 In a 1990 article, ‘Black art and the burden of representation’, Kobena Mercer discusses general expectations about the work of artists of colour. Critics and spectators in Europe and North America, he argues, invariably assume that the work of black artists always ‘represents’ Black identities or addresses the concerns of the Black community. This paper examines the...

  19. East West Fuzzy colloquium 2000. 8. Zittau Fuzzy colloquium. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Wagenknecht, M.; Chaker, N.; Hampel, R. [comps.

    2000-07-01

    The Zittau Colloquium is organized annually with the objective to stimulate contacts between scientists in academic research, industrial development and university teaching from Eastern and Western European countries and from other parts of the world. A further aim of the colloquium is the exchange of information about the state-of-the-art in the field of Fuzzy Logic basic investigation and application in connection with other theories, for example Neuronal Networks. Therefore, we want to stimulate the discussion about proposals for common national, bilateral and international supported projects to incite research, teaching, as well as mobility of students and teachers. (orig.)

  20. PR/VI East-West Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for Puerto Rico and the Virgin Islands is distributed as the DEFLEC96 model. The computation used about 26,000...

  1. Hawaiian Islands East-West Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for the Principal Hawaiian Islands is the DEFLEC96 model. The computation used about 61,000 terrestrial and marine...

  2. The German East-West Divide in Knowledge Production

    DEFF Research Database (Denmark)

    Patuelli, Roberto; Vaona, Andrea; Grimpe, Christoph

    2010-01-01

    Research and development (R&D), in the field of nanomaterials is expected to be a major driver of innovation and economic growth. Consequently, it is of great interest to understand which factors facilitate the creation of new technological knowledge. The existing literature has typically address...

  3. Wetlands & Deepwater Habitats - MO 2012 East West Gateway Wetlands (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Cowardin’s Classification of Wetlands and Deep Water Habitats of the United States (http://www.npwrc.usgs.gov/resource/wetlands/classwet/index.htm), together with...

  4. East-West News Flow "Imbalance": Qualifying the Quantifications.

    Science.gov (United States)

    Le Duc, Don R.

    1981-01-01

    A study of Eurovision-Intervision news exchange patterns suggests that any global explanation for imbalance will be premature until the news item values in each exchange are understood as clearly as its news item volume. (PD)

  5. Easing East-West Tensions in the Third World,

    Science.gov (United States)

    1986-03-01

    policy choices for the U.S. and Mexico. Edited by Richard R. Fagen and Olga Pellicer . R-ETnrd, CA: Stanford University Press, 1983. (F 1439.5 .F88 1983...114-17, March 1985. Astiz, Carlos A. U.S. policy in Latin America. Current History 82:49-51, February 1983. The bases of policy: the State Department’s...132:AIO, 28 July 1983. Cuba is open to talks on ties with U.S. (Vice President Dr. Carlos Rafael Rodriguez to U.S. Press). New York Times 132:A3,17

  6. European East-West migration, 1945-1992.

    Science.gov (United States)

    Fassmann, H; Munz, R

    1994-01-01

    "This article's thesis is that Europe is undergoing an international but intracontinental migration such as it has not seen since the beginning of the Cold War. The authors cite several reasons for the recent outburst of migration: ethnic relocation, the search for refuge and asylum, and the need for work. They also present a country-by-country description of sending and receiving nations. The push and pull factors causing such massive migration cannot only be contained by the present methods of having each government erect legislative and other barriers--such as armed border guards--against newcomers." excerpt

  7. Status of international cooperation and east-west information exchange

    Science.gov (United States)

    Lawrence, Barbara; Bernacki, Adam

    It is proposed that there are certain necessary conditions for sci-tech intellectual transfer to appear in significant, and therefore noticeable, proportions. The two obvious conditions are the existence of a "donor" country (a country which experiences a surplus of intellectual output) and a "recipient" country (one which manages to accommodate foreign intellectual production in its publications). The sci-tech intellectual transfer is likely to occur when the publishing potential of a given country exceeds its intellectual production or when the quality and importance of research performed abroad surpasses internal accomplishments. Patterns of Soviet aerospace science as information donor and recipient have been investigated in a case study. An assessment of two decades of AIAA's (the American Institute of Aeronautics and Astronautics) coverage of the Soviet aerospace and engineering literature in the Aerospace Database demonstrates that the former Soviet Union has been transformed from a recipient of foreign intellectual effort to a donor country. Aspects of utilization/integration of Soviet information are examined, and a survey of the AIAA Journal suggests that Soviet literature entering the U.S. via the alternative channel of distribution (i.e., as a result of international intellectual transfer) is far more likely to be integrated into the mainstream of actively utilized aerospace knowledge. Suggestions for change in this area are presented, with emphasis on ways to reduce language barriers.

  8. KUD SERVICE LEVEL IN FARMER SUBSIDIZE FERTILIZER (Case Study in District Banguntapan Bantul Yogyakarta

    Directory of Open Access Journals (Sweden)

    Sipri Paramita

    2014-01-01

    Full Text Available The purpose of the study was to determine: (1 the level of service in the provision of subsidized fertilizer cooperatives of farmers on the timeliness, accuracy number, precision type, right quality, right place and the right price, (2 factors that affect the level of service cooperatives in the procurement of subsidized fertilizer at the farm level. Descriptively and purposive of the 90 samples taken at random, were analyzed with analysis of the test sample Kolmogorov-Smirnov, the proportion of single test, and correlation analysis. Obtained results: (1 service cooperatives in the procurement of subsidized fertilizer at the farm level right time, right quantity, right price, right quality and the right target is good, (2 service cooperatives have an inverse correlation with the presence of other distributors. Other factors not directly affect the effectiveness of the service cooperatives

  9. Plate boundary deformation and man-made subsidence around geothermal fields on the Reykjanes Peninsula, Iceland

    KAUST Repository

    Keiding, Marie

    2010-07-01

    We present Interferometric Synthetic Aperture Radar (InSAR) data from 1992-1999 and 2003-2008 as well as GPS data from 2000-2009 for the active plate boundary on the Reykjanes Peninsula, southwest Iceland. The geodetic data reveal deformation mainly due to plate spreading, anthropogenic subsidence caused by geothermal fluid extraction and, possibly, increasing pressure in a geothermal system. Subsidence of around 10. cm is observed during the first 2. years of production at the Reykjanes geothermal power plant, which started operating in May 2006. We model the surface subsidence around the new power plant using point and ellipsoidal pressure sources in an elastic halfspace. Short-lived swarms of micro-earthquakes as well as aseismic fault movement are observed near the geothermal field following the start of production, possibly triggered by the stresses induced by geothermal fluid extraction. © 2010 Elsevier B.V.

  10. Investigation of alternative mechanisms of aquifer-system compaction and land subsidence in Shanghai

    Directory of Open Access Journals (Sweden)

    Y. Yuan

    2015-11-01

    Full Text Available Alternative subsidence mechanisms related to groundwater extration and surface loading of built infrastructure in Shanghai have been evaluated to explain continued subsidence despite the controlled reduction of groundwater extraction. The traditional theory of aquifer-system compaction embodied in the aquitard drainage model cannot fully explain this phenomenon. Two possible alternative mechanisms were studied previously: (i surface loading attributed to urban construction; (ii creep occuring in sandy deposits of aquifers. These mechanisms could not fully explain the observed subsidence. Two additional alternative mechanistic models are proposed that involve principles of load transfer considering the temporally and spatially redistributed stresses associated with groundwater extraction: (i the Cosserat continuum mechanism, considering shear force on the permeable coarse-grained matrial in the aquifer due to hydraulic gradients in the aquifer; and (ii internal erosion of fine-grained (clay and silt particles within the aquifer. Initial results based on simulations incorporating Cosserat mechanics look promising.

  11. The Identification of Land Subsidance by Levelling Measurement and GPR Data at Tanjung Emas Harbour, Semarang

    Directory of Open Access Journals (Sweden)

    Purnomo Raharjo

    2017-10-01

    Full Text Available Recently, the main problem in Semarang City is flood. This area has low relief that consists of coastal alluvial deposits, swamp and marine sediments. The coastline is characterized by muddy, sandy, and rocky coasts, and mangrove coast. Ground Penetrating Radar (GPR records, show that subsurface geological condition of northern part of Semarang is coastal alluvial deposit and in the south is volcanic rocks. The aims of this this research is to determine land subsidence by levelling measurement in 2005 in Tanjung Emas Harbour area built on 1995. During ten years, there are various land subsidance in this area: in Coaster Street (21 – 41 cm, container wharf (62 – 94 cm, north breakwater (64 – 79 cm, west breakwater (74 – 140 cm, east groin (76 – 89 cm, and stacking area ( 77 – 109 cm. According to this research, it is concluded that one reason causes of flooding in this area is land subsidence.

  12. Subsidence related to groundwater pumping for breweries in Merchtem area (Belgium), highlighted by Persistent Scaterrer Interferometry

    Science.gov (United States)

    Declercq, Pierre-Yves; Gerard, Pierre; Pirard, Eric; Perissin, Daniele; Walstra, Jan; Devleeschouwer, Xavier

    2017-12-01

    ERS, ENVISAT and TerraSAR-X Synthetic Aperture Radar scenes covering the time span 1992-2014 were processed using a Persistent Scatterer technique to study the ground movements in Merchtem (25 km NW of Brussels, Belgium). The processed datasets, covering three consecutive time intervals, reveal that the investigated area is affected by a global subsidence trend related to the extraction of groundwater in the deeper Cambro-Silurian aquifer. Through time the subsidence pattern is reduced and replaced by an uplift related to the rising water table attested by piezometers located in this aquifer. The subsidence is finally reduced to a zone where currently three breweries are very active and pump groundwater in the Ledo-Paniselian aquifer and in the Cambro-Silurian for process water for the production.

  13. Environmental and economic effects of subsidence: Category 4, Project 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Viets, V.F.; Vaughan, C.K.; Harding, R.C.

    1979-05-01

    A list of more than 70 subsidence areas was screened to select those areas which seemed to have the best potential for providing reliable data. The screening process is described in an appendix. Nine areas were selected for detailed case studies to collect all available data on the environmental and economic effects of the subsidence. Available information from the subsidence areas not selected as case studies was tabulated for each area and is included in an appendix. The nine case study areas are: Arizona; San Joaquin Valley, California; Baldwin Hills, California; Santa Clara Valley, California; Wilmington, California; Las Vegas Valley, Nevada; Houston-Galveston area, Texas; Mexico City, Mexico; and Wairakei, New Zealand. (MHR)

  14. Approximation of average course of measured subsidences of mining area by smooth splines

    Science.gov (United States)

    Orwat, Justyna

    2017-07-01

    The article presents the way of determining an average course of subsidences of mining area measured after the termination of the subsequent mining stages run in the south of Poland by "Chwałowice" coalmine. The mean square approximation was conducted via smooth spline with the use of R - project programme. The problem of ambiguity of parameter value of smoothing of approximation function spar (in case when the function illustrating dependence among parameter values of smoothing and values obtained by generalised cross validation reaches its minimum value in a certain range of its values) was solved with the use of mean square minimalisation criterion of loss function between approximated and forecast subsidence values of Bialek's formulas and the Budryk-Knothe theory. The efficiency of both forecasts was verified as well as their accuracy was estimated based on average course of measured subsidences.

  15. Land subsidence caused by groundwater exploitation in Suzhou City, China

    Science.gov (United States)

    Chen, Chongxi; Pei, Shunping; Jiao, Jiu Jimmy

    2002-09-01

    Suzhou City, located at the lower reaches of the Yangtze River in southeastern Jiangsu Province, is one of the few cities in China which suffer from severe ground settlement. A research project was carried out to investigate this problem. Geological and hydrogeological studies show that there is a multi-layered aquifer system with three distinct, soft mud layers of marine and lagoonal origins. An examination of historical records of groundwater extraction, water levels, and ground settlement shows that the ground subsidence is associated with the continuously increasing groundwater extraction in the deep, confined aquifer. It is believed that the consolidation of the soft mud layers, especially the third layer which is thick and close to the main pumped aquifer, contributes to the ground settlement. A three-dimensional finite difference numerical model representing the multi-layered aquifer system was developed to study the ground settlement in response to groundwater extraction. By calibrating the model with both the measured groundwater level and ground settlement, the aquifer parameters were estimated. The model outputs fit reasonably well with the observed results, which indicates that the numerical model can reproduce the dynamic processes of both groundwater flow and soil consolidation. The hydraulic conductivity of the third mud layer near the center of the ground settlement has been reduced by over 30% in the last 14 years. The gradual deterioration in the hydraulic conductivity of the mud may have significant adverse effect on the sustainable groundwater resource of the deep confined aquifer, since the recharge from the shallow aquifers through the mud layer is the only source of water to the deep aquifer. An analysis of the spatial distributions of groundwater drawdown and ground settlement shows that the area with maximum drawdown is not necessarily the area with maximum ground settlement due to the occurrence of the soft mud layer. A simple reallocation

  16. Subsidence Modeling of the Over-exploited Granular Aquifer System in Aguascalientes, Mexico

    Science.gov (United States)

    Solano Rojas, D. E.; Wdowinski, S.; Minderhoud, P. P. S.; Pacheco, J.; Cabral, E.

    2016-12-01

    The valley of Aguascalientes in central Mexico experiences subsidence rates of up to 100 [mm/yr] due to overexploitation of its aquifer system, as revealed from satellite-based geodetic observations. The spatial pattern of the subsidence over the valley is inhomogeneous and affected by shallow faulting. The understanding of the subsoil mechanics is still limited. A better understanding of the subsidence process in Aguascalientes is needed to provide insights for future subsidence in the valley. We present here a displacement-constrained finite-element subsidence model using Deltares iMOD (interactive MODeling), based on the USGS MODFLOW software. The construction of our model relies on 3 main inputs: (1) groundwater level time series obtained from extraction wells' hydrographs, (2) subsurface lithostratigraphy interpreted from well drilling logs, and (3) hydrogeological parameters obtained from field pumping tests. The groundwater level measurements were converted to pore pressure in our model's layers, and used in Terzaghi's equation for calculating effective stress. We then used the effective stresse along with the displacement obtained from geodetic observations to constrain and optimize five geo-mechanical parameters: compression ratio, reloading ratio, secondary compression index, over consolidation ratio, and consolidation coefficient. Finally, we use the NEN-Bjerrum linear stress model formulation for settlements to determine elastic and visco-plastic strain, accounting for the aquifer system units' aging effect. Preliminary results show higher compaction response in clay-saturated intervals (i.e. aquitards) of the aquifer system, as reflected in the spatial pattern of the surface deformation. The forecasted subsidence for our proposed scenarios show a much more pronounced deformation when we consider higher groundwater extraction regimes.

  17. Calibration of a Land Subsidence Model Using InSAR Data via the Ensemble Kalman Filter.

    Science.gov (United States)

    Li, Liangping; Zhang, Meijing; Katzenstein, Kurt

    2017-05-23

    The application of interferometric synthetic aperture radar (InSAR) has been increasingly used to improve capabilities to model land subsidence in hydrogeologic studies. A number of investigations over the last decade show how spatially detailed time-lapse images of ground displacements could be utilized to advance our understanding for better predictions. In this work, we use simulated land subsidences as observed measurements, mimicking InSAR data to inversely infer inelastic specific storage in a stochastic framework. The inelastic specific storage is assumed as a random variable and modeled using a geostatistical method such that the detailed variations in space could be represented and also that the uncertainties of both characterization of specific storage and prediction of land subsidence can be assessed. The ensemble Kalman filter (EnKF), a real-time data assimilation algorithm, is used to inversely calibrate a land subsidence model by matching simulated subsidences with InSAR data. The performance of the EnKF is demonstrated in a synthetic example in which simulated surface deformations using a reference field are assumed as InSAR data for inverse modeling. The results indicate: (1) the EnKF can be used successfully to calibrate a land subsidence model with InSAR data; the estimation of inelastic specific storage is improved, and uncertainty of prediction is reduced, when all the data are accounted for; and (2) if the same ensemble is used to estimate Kalman gain, the analysis errors could cause filter divergence; thus, it is essential to include localization in the EnKF for InSAR data assimilation. © 2017, National Ground Water Association.

  18. New information on regional subsidence and soil fracturing in Mexico City Valley

    Directory of Open Access Journals (Sweden)

    G. Auvinet

    2015-11-01

    Full Text Available In this paper, updated information about regional subsidence in Mexico City downtown area is presented. Data obtained by R. Gayol in 1891, are compared with information obtained recently from surveys using the reference points of Sistema de Aguas de la Ciudad de México (2008 and on the elevation of a cloud of points on the ground surface determined using Light Detection and Ranging (LiDAR technology. In addition, this paper provides an overview of recent data obtained from systematic studies focused on understanding soil fracturing associated with regional land subsidence and mapping of areas susceptible to cracking in Mexico City Valley.

  19. Is land subsidence increasing the exposure to sea level rise in Alexandria, Egypt?

    OpenAIRE

    Wöppelmann, Guy; Le Cozannet, Gonéri; De Michele, Marcello; Raucoules, Daniel; Cazenave, Anny; Garcin, Manuel; Hanson, Susan; Marcos, Marta; Santamaría-Gómez, Álvaro

    2013-01-01

    Delta margins are subject to relatively high rates of land subsidence and have the potential to significantly exacerbate future changes in sea levels predicted by global warming models used in impact studies. Through a combined analysis of GPS and persistent scatterer interferometry data, we determine that most of the coastline of Alexandria has been subject to moderate land subsidence over the past decade (0.4 mm/yr on average and up to 2 mm/yr locally). This contrasts to previous studies th...

  20. New information on regional subsidence and soil fracturing in Mexico City Valley

    Science.gov (United States)

    Auvinet, G.; Méndez-Sánchez, E.; Juárez-Camarena, M.

    2015-11-01

    In this paper, updated information about regional subsidence in Mexico City downtown area is presented. Data obtained by R. Gayol in 1891, are compared with information obtained recently from surveys using the reference points of Sistema de Aguas de la Ciudad de México (2008) and on the elevation of a cloud of points on the ground surface determined using Light Detection and Ranging (LiDAR) technology. In addition, this paper provides an overview of recent data obtained from systematic studies focused on understanding soil fracturing associated with regional land subsidence and mapping of areas susceptible to cracking in Mexico City Valley.

  1. Land subsidence phenomena in urbanized areas of Attica observed by applying advanced DinSAR techniques

    Science.gov (United States)

    Kaitantzian, A.; Parcharidis, I.; Loupasakis, C.

    2017-09-01

    Synthetic Aperture Radar Interferometry (SAR) technology has been enabled to investigate the spatial distribution and temporal evolution of displacements occurring at the areas due to land subsidence related hazards. Land motion mapping data, produced by hybrid interferometric technique (Singular Value Decomposition algorithm) and PSI (Persistent Scatterer Interferometry) analysis, revealed vertical displacements affecting the Thriassio basin and the region of Moschato. The outcomes of these techniques provided important information about the spatial extent and time series of the surface deformation that should be evaluated considering the geological, hydrogeological, morphological and tectonic settings of the areas to assess land subsidence hazard mechanism.

  2. Production induced subsidence and seismicity in the Groningen gas field – can it be managed?

    Directory of Open Access Journals (Sweden)

    J. A. de Waal

    2015-11-01

    Full Text Available Reliable prediction of the induced subsidence resulting from gas production is important for a near sea level country like the Netherlands. Without the protection of dunes, dikes and pumping, large parts of the country would be flooded. The predicted sea-level rise from global warming increases the challenge to design proper mitigation measures. Water management problems from gas production induced subsidence can be prevented if measures to counter its adverse effects are taken timely. This requires reliable subsidence predictions, which is a major challenge. Since the 1960's a number of large, multi-decade gas production projects were started in the Netherlands. Extensive, well-documented subsidence prediction and monitoring technologies were applied. Nevertheless predicted subsidence at the end of the Groningen field production period (for the centre of the bowl went from 100 cm in 1971 to 77 cm in 1973 and then to 30 cm in 1977. In 1984 the prediction went up again to 65 cm, down to 36 cm in 1990 and then via 38 cm (1995 and 42 cm (2005 to 47 cm in 2010 and 49 cm in 2013. Such changes can have large implications for the planning of water management measures. Until 1991, when the first event was registered, production induced seismicity was not observed nor expected for the Groningen field. Thereafter the number of observed events rose from 5 to 10 per year during the 1990's to well over a hundred in 2013. The anticipated maximum likely magnitude rose from an initial value of less than 3.0 to a value of 3.3 in 1993 and then to 3.9 in 2006. The strongest tremor to date occurred near the village of Huizinge in August 2012. It had a magnitude of 3.6, caused significant damage and triggered the regulator into an independent investigation. Late 2012 it became clear that significantly larger magnitudes cannot be excluded and that values up to magnitude 5.0 cannot be ruled out. As a consequence the regulator advised early 2013 to lower Groningen gas

  3. The Correlation Analysis of Subsidence Monitoring by D-Insar and the Change of Urban Construction Land

    Science.gov (United States)

    Yang, K. J.; Jiang, X. X.; Cao, L.; Lei, F.; Zeng, H.; Zhang, Z.

    2017-05-01

    The change of urban construction land affect the subsidence directly or indirectly, the method of D-InSAR has centimeter level or even millimeter accuracy that can provide a reliable and accurate data for the research of correlation analysis of subsidence monitoring by D-InSAR and the change of urban construction land. This article takes Guiyang, Nanning city as example, using 3m level TerraSAR data to construct the Subsidence model by interferometric measurement, then compared with the Chinese national land use change remote sensing survey database at the same measure time to have a correlation analysis GIS research between subsidence and the change of urban construction land. The results shows that the integral correlation coefficient achieved 0.78 between subsidence and the change of urban construction land, the major construction area and the high density construction area are with severe land subsidence. In addition, the correlation coefficient increased from the main city to the suburbs, indicates that some of the main city causes permanent settlement and is difficult to recover. It also shows that some area subsidence caused by long-term mining or other natural factors has no strong correlation with the change of urban construction land, therefore, the results of D-InSAR subsidence monitoring have a reaction on urban construction planning, guiding urban planning to high stability, low settlement area.

  4. THE CORRELATION ANALYSIS OF SUBSIDENCE MONITORING BY D-INSAR AND THE CHANGE OF URBAN CONSTRUCTION LAND

    Directory of Open Access Journals (Sweden)

    K. J. Yang

    2017-05-01

    Full Text Available The change of urban construction land affect the subsidence directly or indirectly, the method of D-InSAR has centimeter level or even millimeter accuracy that can provide a reliable and accurate data for the research of correlation analysis of subsidence monitoring by D-InSAR and the change of urban construction land. This article takes Guiyang, Nanning city as example, using 3m level TerraSAR data to construct the Subsidence model by interferometric measurement, then compared with the Chinese national land use change remote sensing survey database at the same measure time to have a correlation analysis GIS research between subsidence and the change of urban construction land. The results shows that the integral correlation coefficient achieved 0.78 between subsidence and the change of urban construction land, the major construction area and the high density construction area are with severe land subsidence. In addition, the correlation coefficient increased from the main city to the suburbs, indicates that some of the main city causes permanent settlement and is difficult to recover. It also shows that some area subsidence caused by long-term mining or other natural factors has no strong correlation with the change of urban construction land, therefore, the results of D-InSAR subsidence monitoring have a reaction on urban construction planning, guiding urban planning to high stability, low settlement area.

  5. Lithology-controlled subsidence and seasonal aquifer response in the Bandung basin, Indonesia, observed by synthetic aperture radar interferometry

    Science.gov (United States)

    Khakim, Mokhamad Yusup Nur; Tsuji, Takeshi; Matsuoka, Toshifumi

    2014-10-01

    Land subsidence in the Bandung basin, West Java, Indonesia, is characterized based on differential interferometric synthetic aperture radar (DInSAR) and interferometric point target analysis (IPTA). We generated interferograms from 21 ascending SAR images over the period 1 January 2007 to 3 March 2011. The estimated subsidence history shows that subsidence continuously increased reaching a cumulative 45 cm during this period, and the linear subsidence rate reached ∼12 cm/yr. This significant subsidence occurred in the industrial and densely populated residential regions of the Bandung basin where large amounts of groundwater are consumed. However, in several areas the subsidence patterns do not correlate with the distribution of groundwater production wells and mapped aquifer degradation. We conclude that groundwater production controls subsidence, but lithology is a counteracting factor for subsidence in the Bandung basin. Moreover, seasonal trends of nonlinear surface deformations are highly related with the variation of rainfall. They indicate that there is elastic expansion (rebound) of aquifer system response to seasonal-natural recharge during rainy season.

  6. Tectonic subsidence of the Zhu 1 Sub-basin in the Pearl River Mouth Basin, northern South China Sea

    Science.gov (United States)

    Tang, Xiaoyin; Yang, Shuchun; Zhu, Junzhang; Long, Zulie; Jiang, Guangzheng; Huang, Shaopeng; Hu, Shengbiao

    2017-12-01

    The Pearl River Mouth Basin, which is situated on the northern margin of the South China Sea, has attracted great attention not only because of its tectonic setting but also because of its abundant hydrocarbon resources. We have analyzed the Cenozoic tectonic subsidence history of 4 drilled wells and 43 artificial wells from the Zhu 1 Sub-basin of the Pearl River Mouth Basin by back-stripping, using newly interpreted seismic profiles. We also calculated the average tectonic subsidence rates of the four sags in the Zhu 1 Sub-basin. The rifting and post-rifting stages are separated by abrupt changes in the tectonic subsidence curves and average subsidence rates. In the eastern sags of the Zhu 1 Sub-basin, tectonic subsidence started to slow at ca. 30 Ma, compared with ca. 23.8 Ma in the western sags. This probably corresponds to the timing of break-up and suggests that rifting in the Pearl River Mouth Basin ended earlier in the eastern sags than in the western sags. Anomalously accelerated tectonic subsidence occurred at 17.5-16.4 Ma during the post-rifting stage, with average subsidence rates as high as 301.9 m/Myr. This distinguishes the Pearl River Mouth Basin from classical Atlantic passive continental marginal basins, which demonstrate exponentially decaying post-rift tectonic subsidence.

  7. Numerical Modeling of Mechanical Behavior for Buried Steel Pipelines Crossing Subsidence Strata.

    Science.gov (United States)

    Zhang, J; Liang, Z; Han, C J

    2015-01-01

    This paper addresses the mechanical behavior of buried steel pipeline crossing subsidence strata. The investigation is based on numerical simulation of the nonlinear response of the pipeline-soil system through finite element method, considering large strain and displacement, inelastic material behavior of buried pipeline and the surrounding soil, as well as contact and friction on the pipeline-soil interface. Effects of key parameters on the mechanical behavior of buried pipeline were investigated, such as strata subsidence, diameter-thickness ratio, buried depth, internal pressure, friction coefficient and soil properties. The results show that the maximum strain appears on the outer transition subsidence section of the pipeline, and its cross section is concave shaped. With the increasing of strata subsidence and diameter-thickness ratio, the out of roundness, longitudinal strain and equivalent plastic strain increase gradually. With the buried depth increasing, the deflection, out of roundness and strain of the pipeline decrease. Internal pressure and friction coefficient have little effect on the deflection of buried pipeline. Out of roundness is reduced and the strain is increased gradually with the increasing of internal pressure. The physical properties of soil have a great influence on the mechanical properties of buried pipeline. The results from the present study can be used for the development of optimization design and preventive maintenance for buried steel pipelines.

  8. Coastal subsidence in Oregon, USA during the giant Cascadia earthquake of AD 1700

    Science.gov (United States)

    Hawkes, A.D.; Horton, B.P.; Nelson, A.R.; Vane, C.H.; Sawai, Y.

    2011-01-01

    Quantitative estimates of land-level change during the giant AD 1700 Cascadia earthquake along the Oregon coast are inferred from relative sea-level changes reconstructed from fossil foraminiferal assemblages preserved within the stratigraphic record. A transfer function, based upon a regional training set of modern sediment samples from Oregon estuaries, is calibrated to fossil assemblages in sequences of samples across buried peat-mud and peat-sand contacts marking the AD 1700 earthquake. Reconstructions of sample elevations with sample-specific errors estimate the amount of coastal subsidence during the earthquake at six sites along 400 km of coast. The elevation estimates are supported by lithological, carbon isotope, and faunal tidal zonation data. Coseismic subsidence at Nehalem River, Nestucca River, Salmon River, Alsea Bay, Siuslaw River and South Slough varies between 0.18 m and 0.85 m with errors between 0.18 m and 0.32 m. These subsidence estimates are more precise, consistent, and generally lower than previous semi-quantitative estimates. Following earlier comparisons of semi-quantitative subsidence estimates with elastic dislocation models of megathrust rupture during great earthquakes, our lower estimates for central and northern Oregon are consistent with modeled rates of strain accumulation and amounts of slip on the subduction megathrust, and thus, with a magnitude of 9 for the AD 1700 earthquake.

  9. Subsidence analysis Forsmark nuclear power plant - unit 1; Saettningsanalys Forsmarks kaernkraftverk - aggregat 1

    Energy Technology Data Exchange (ETDEWEB)

    Bono, Nancy; Fredriksson, Anders; Maersk Hansen, Lars (Golder Associates AB (Sweden))

    2010-12-15

    On behalf of SKB, Golder Associates Ltd carried out a risk analysis of subsidence during Forsmark nuclear power plant in the construction of the final repository for spent nuclear fuel near and below existing reactors. Specifically, the effect of horizontal cracks have been studied.

  10. SINTEF Project Sheds Light on Mechanics of Reservoir Compaction and Subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Hokstad, Ketil; Wulff, Angelika; Mjaaland, Svein; Paramichos, Euripides

    2000-07-01

    The seabed of the Ekofisk oil field in the North Sea is now eight metres lower than it used to be before production started in 1971. The article deals very briefly with work done at SINTEF Petroleum Research on the physics and mechanisms of reservoir compaction and subsidence.

  11. Land subsidence susceptibility and hazard mapping: the case of Amyntaio Basin, Greece

    Science.gov (United States)

    Tzampoglou, P.; Loupasakis, C.

    2017-09-01

    Landslide susceptibility and hazard mapping has been applying for more than 20 years succeeding the assessment of the landslide risk and the mitigation the phenomena. On the contrary, equivalent maps aiming to study and mitigate land subsidence phenomena caused by the overexploitation of the aquifers are absent from the international literature. The current study focuses at the Amyntaio basin, located in West Macedonia at Florina prefecture. As proved by numerous studies the wider area has been severely affected by the overexploitation of the aquifers, caused by the mining and the agricultural activities. The intensive ground water level drop has triggered extensive land subsidence phenomena, especially at the perimeter of the open pit coal mine operating at the site, causing damages to settlements and infrastructure. The land subsidence susceptibility and risk maps were produced by applying the semi-quantitative WLC (Weighted Linear Combination) method, especially calibrated for this particular catastrophic event. The results were evaluated by using detailed field mapping data referring to the spatial distribution of the surface ruptures caused by the subsidence. The high correlation between the produced maps and the field mapping data, have proved the great value of the maps and of the applied technique on the management and the mitigation of the phenomena. Obviously, these maps can be safely used by decision-making authorities for the future urban safety development.

  12. Integrating interferometric SAR data with levelling measurements of land subsidence using geostatistics

    NARCIS (Netherlands)

    Zhou, Y.; Stein, A.; Molenaar, M.

    2003-01-01

    Differential Synthetic Aperture Radar (SAR) interferometric (D-InSAR) data of ground surface deformation are affected by several error sources associated with image acquisitions and data processing. In this paper, we study the use of D-InSAR for quantifying land subsidence due to groundwater

  13. Tectonic subsidence history and source-rock maturation in the Campos Basin, Brazil

    NARCIS (Netherlands)

    Beglinger, S.E.; Wees, J.D. van; Cloetingh, S.; Doust, H.

    2012-01-01

    The Campos Basin is a petroleum-productive, marginal sag basin along the Brazilian margin. It contains a stratigraphic sequence recording lithospheric extension and rift tectonics developing to a fully evolved postbreakup setting. We present a combined approach using subsidence analysis and basin

  14. Differential substrate subsidence of the EnviHUT project pitched extensive green roof

    Directory of Open Access Journals (Sweden)

    Nečadová Klára

    2017-01-01

    Full Text Available In primary phase of testing building physical characteristics of the EnviHUT project extensive and semi-intensive roofs with 30° inclination occurred exceptional substrate subsidence. An extensive testing field with retaining geocell-system evinced differential subsidence of individual sectors after six months. Measured subsidence of installed substrate reached 40 % subsidence compared to originally designed height (intended layer thickness. Subsequent deformation of geocell-system additionally caused partial slide of substrate to drip edge area. These slides also influenced initial development of stonecrop plants on its surface. Except functional shortages the aesthetical function of the whole construction is influenced by the mentioned problem. The stated paper solves mentioned issues in view of installation method optimization, selection and modification of used roof substrate and in view of modification of geometric and building installed elements retaining system arrangement. Careful adjustment of roof system geometry and enrichment of original substrate fraction allow full functionality from pitched extensive green roof setting up. The modification scheme and its substantiation is a part of this technical study output.

  15. Past and future plant diversity of a coastal wetland driven by soil subsidence and climate change

    NARCIS (Netherlands)

    Dobben, van H.F.; Slim, P.A.

    2012-01-01

    On the island of Ameland (The Netherlands), natural gas has been extracted from a dune and salt marsh natural area since 1986. This has caused a soil subsidence of c. 1–25 cm, which can be used as a model to infer effects of future sea level rise. The aims of our study were (a) to relate the changes

  16. Analysis of Factors in Land Subsidence in Shanghai: A View Based on a Strategic Environmental Assessment

    Directory of Open Access Journals (Sweden)

    Ye-Shuang Xu

    2016-06-01

    Full Text Available It has been observed that in the urban center of Shanghai, land subsidence has accelerated, and the groundwater level has continued to drop even though the net withdrawn volume (NWV of groundwater has remained unchanged since 1980. An analysis of monitoring data shows that drawdown of the groundwater level is one of the factors that have influenced land subsidence since 1980. The NWV of groundwater in urban areas, however, is not the critical factor controlling the drawdown of the groundwater level. Since the 1980s, there have been many underground works constructed in the unique strata of Shanghai, which has an interlayered structure known as a multi-aquifer-aquitard system (MAAS. Investigation into land subsidence caused by urban construction is now receiving much attention. Based on the principle of a strategic environmental assessment (SEA for sustainable urban development, this paper presents a discussion and analysis of the factors which can influence the development of land subsidence during continued urbanization in Shanghai. The main factors include the additional loading caused by the construction of structures, the cut-off effect due to construction in aquifers, the drawdown of groundwater level caused by leakage into underground structures, and the decrease of groundwater recharge from neighboring zones. SEA is recommended for the future development of Shanghai.

  17. Numerical Modeling of Mechanical Behavior for Buried Steel Pipelines Crossing Subsidence Strata.

    Directory of Open Access Journals (Sweden)

    J Zhang

    Full Text Available This paper addresses the mechanical behavior of buried steel pipeline crossing subsidence strata. The investigation is based on numerical simulation of the nonlinear response of the pipeline-soil system through finite element method, considering large strain and displacement, inelastic material behavior of buried pipeline and the surrounding soil, as well as contact and friction on the pipeline-soil interface. Effects of key parameters on the mechanical behavior of buried pipeline were investigated, such as strata subsidence, diameter-thickness ratio, buried depth, internal pressure, friction coefficient and soil properties. The results show that the maximum strain appears on the outer transition subsidence section of the pipeline, and its cross section is concave shaped. With the increasing of strata subsidence and diameter-thickness ratio, the out of roundness, longitudinal strain and equivalent plastic strain increase gradually. With the buried depth increasing, the deflection, out of roundness and strain of the pipeline decrease. Internal pressure and friction coefficient have little effect on the deflection of buried pipeline. Out of roundness is reduced and the strain is increased gradually with the increasing of internal pressure. The physical properties of soil have a great influence on the mechanical properties of buried pipeline. The results from the present study can be used for the development of optimization design and preventive maintenance for buried steel pipelines.

  18. Subsidence detection in Grizzly Island in the Sacramento-San Joaquin Delta, California

    Science.gov (United States)

    Martinez-Torres, F. A.; Brooks, B. A.; Glennie, C. L.; Hauser, D.; Ericksen, T.; Hudnut, K. W.; LeWinter, A.; Pollitz, F. F.; Finnegan, D. C.

    2016-12-01

    The Sacramento-San Joaquin Delta is a vital resource for the state of California, providing fresh water to approximately one million cultivated hectares and more than two thirds of the state population. This freshwater resource is protected by several inner islands in the delta and a system of levees that extends 1,700 kilometer and prevents salt water influx from the nearby bay. In the past, subsidence has been detected at these levees, which presents a potential hazard for the inner islands that are several meters under sea level. We use airborne and terrestrial LIDAR data from Grizzly island collected in 2007 and 2015 to deduce the rate of subsidence of portions of the island in order to quantified this ongoing event. By georeferencing, correcting for secular plate motion, and differencing these two data sets we have produced a preliminary map indicating a subsidence rate between 3 to 7.5 cm/yr within several unvegetated sections of the island, including roads adjacent to the levees. Our results show that differential LIDAR should be used as one of the tools to continue monitoring the subsidence of the Delta inner islands.

  19. Modeling of earth fissures caused by land subsidence due to groundwater withdrawal

    Directory of Open Access Journals (Sweden)

    B. B. Panda

    2015-11-01

    Full Text Available Land subsidence and earth fissures are phenomena related to groundwater withdrawal in a sedimentary basin. If the rock basement or basin lithology is irregular, both vertical and horizontal displacements can be induced due to differential settlement and tensile stresses appearing in the soil mass. If the differential settlement is of sufficient magnitude, earth fissuring can occur within tensile zones. The magnitudes of compaction and fissure geometry are closely related to the thickness and skeletal compressibility of fine-grained sediments within the aquifer system. Land subsidence and earth fissuring were modeled by employing a two-dimensional (2-D coupled seepage and stress-strain finite element analysis. The basin bedrock geometry, lithological variation, measurements of surface displacements, and changes in hydraulic head were the critical input parameter for the subsidence modeling. Simulation results indicate that strain had exceeded the approximate threshold for fissure formation of 0.02 to 0.06 % in the area of the identified fissures. The numerical model was used to predict future subsidence and potential earth fissures for flood control structures within the metro Phoenix area.

  20. Groundwater-abstraction induced land subsidence and groundwater regulation in the North China Plain

    Science.gov (United States)

    Guo, H.; Wang, L.; Cheng, G.; Zhang, Z.

    2015-11-01

    Land subsidence can be induced when various factors such as geological, and hydrogeological conditions and intensive groundwater abstraction combine. The development and utilization of groundwater in the North China Plain (NCP) bring great benefits, and at the same time have led to a series of environmental and geological problems accompanying groundwater-level declines and land subsidence. Subsidence occurs commonly in the NCP and analyses show that multi-layer aquifer systems with deep confined aquifers and thick compressible clay layers are the key geological and hydrogeological conditions responsible for its development in this region. Groundwater overdraft results in aquifer-system compaction, resulting in subsidence. A calibrated, transient groundwater-flow numerical model of the Beijing plain portion of the NCP was developed using MODFLOW. According to available water supply and demand in Beijing plain, several groundwater regulation scenarios were designed. These different regulation scenarios were simulated with the groundwater model, and assessed using a multi-criteria fuzzy pattern recognition model. This approach is proven to be very useful for scientific analysis of sustainable development and utilization of groundwater resources. The evaluation results show that sustainable development of groundwater resources may be achieved in Beijing plain when various measures such as control of groundwater abstraction and increase of artificial recharge combine favourably.

  1. Quantifying subsidence of the Sunda shelf (SE Asia) from coral reef morphology

    Science.gov (United States)

    Sarr, Anta-Clarisse; Husson, Laurent; Pastier, Anne-Morwenn; Becker, Thorsten; Holt, Adam; Alpert, Lisa; Arias Ruiz, Camillo; Elliot, Mary; Pedoja, Kevin; Imran, Andi Muhammad

    2017-04-01

    The vertical motions of the lithosphere have deeply shaped the geography of SE Asia over the last 5 Myrs. The wide continental Sunda and Sahul platforms have been periodically inundated in the West and Southeast, respectively, whereas myriad of islands have emerged in the more central region of "Wallacea". The long wavelength pattern of vertical motion is mirrored by the coastal geomorphology, which displays a striking bimodal repartition throughout the area. Sequences of uplifted terraces, notches and cliffs are prominent in Wallacea - and attest for its general uplift. Conversely, emerged paleo-reefs are absent above modern reefs and wide alluvial plains dominate coastal areas surrounding Sunda and Sahul shelves and suggests that subsidence prevails. In order to quantify the subsidence of the Sunda shelf, we used a probabilistic approach based on a numerical model that reproduces the development of coral reefs sequences trough time, in response to relative sea level variations. The model accounts for growth reef rate, sea level variations, sub-marine erosion and subsequent sedimentation. This method enables to evaluate the field of parameters (slope, vertical rate, reef growth rate) that satisfyingly reproduce the observed morphology. Comparison of the predicted and observed morphologies of the island of Belitung (Sunda shelf) yields short-term subsidence rates ranging from -0.20 to -0.45 mm/yr. Because the shelf is really shallow (typically - 30 m, and up to -120 m), such subsidence rates set the timing of the drowning of Sundaland. It implies that the platform would have been permanently emerged recently, even during period of high sea level stand. The slower, long-term Neogene subsidence of SE Asia, responds to the subduction dynamics of the Sumatra-Java slab. We tested the possibility that the collision of the Australian continent with the Banda Arc modified this long-term behavior. Because the transition from oceanic subduction to continental collision

  2. Determination of intensity functions for predicting subsidence from coal mining, potash mining, and groundwater withdrawal using the influence function technique

    Energy Technology Data Exchange (ETDEWEB)

    Triplett, T.; Yurchak, D. [Twin Cities Research Center, Bureau of Mines, US Dept. of the Interior, Minneapolis, MN (United States)

    1996-12-31

    This paper presents research, conducted by the Bureau of Mines, on modifying the influence function method to predict subsidence. According to theory, this technique must incorporate an intensity function to represent the relative significance of the causes of subsidence. This paper shows that the inclusion of a reasonable intensity function increases the accuracy of the technique, then presents the required functions for case studies of longwall coal mining subsidence in Illinois, USA, potash mining subsidence in new Mexico, USA, and subsidence produced by ground water withdrawal in California, USA. Finally, the paper discusses a method to predict the resultant strain from a simply measured site constant and ground curvatures calculated by the technique. (orig.)

  3. MONITORING OF LAND SUBSIDENCE IN RAVENNA MUNICIPALITY USING INTEGRATED SAR - GPS TECHNIQUES: DESCRIPTION AND FIRST RESULTS

    Directory of Open Access Journals (Sweden)

    G. Artese

    2016-06-01

    Full Text Available The Emilia Romagna Region (N-E Italy and in particular the Adriatic Sea coastline of Ravenna, is affected by a noticeable subsidence that started in the 1950s, when the exploitation of on and off-shore methane reservoirs began, along with the pumping of groundwater for industrial uses. In such area the current subsidence rate, even if lower than in the past, reaches the -2 cm/y. Over the years, local Authorities have monitored this phenomenon with different techniques: spirit levelling, GPS surveys and, more recently, Differential Interferometric Synthetic Aperture Radar (DInSAR techniques, confirming the critical situation of land subsidence risk. In this work, we present the comparison between the results obtained with DInSAR and GPS techniques applied to the study of the land subsidence in the Ravenna territory. With regard to the DInSAR, the Small Baseline Subset (SBAS and the Coherent Pixel Technique (CPT techniques have been used. Different SAR datasets have been exploited: ERS-1/2, ENVISAT, TerraSAR-X and Sentinel-1. Some GPS campaigns have been also carried out in a subsidence prone area. 3D vertices have been selected very close to existing persistent scatterers in order to link the GPS measurement results to the SAR ones. GPS data were processed into the International reference system and the comparisons between the coordinates, for the first 6 months of the monitoring, provided results with the same trend of the DInSAR data, even if inside the precision of the method.

  4. Advanced subsidence monitoring using persistent scatterer interferometry for Jharia Coal Field, Dhanbad, India

    Science.gov (United States)

    Thapa, Shailaja; Chatterjee, R. S.; Kumar, Dheeraj; Singh, K. B.; Sengar, Vivek

    2017-10-01

    This paper presents a spatiotemporal study of surface subsidence over urban area due to coal mining using Persistent scatterer interferometry. In the past few years Differential Interferometric Synthetic Aperture Radar has emerged as a very useful remote sensing technique for measuring land subsidence. It plays a vital role in insitu subsidence prediction of coal mining area. However there are some limitation viz. atmospheric decorrelation, temporal decorrelation and spatial decorrelation with conventional D-InSAR techniques, which can be overcome up to certain extent by using multiinterferogram framework approach. The Persistent Scatterer interferometry technique comprises of more number of SAR datasets, it only concentrates over the pixel which remain coherent over long time period. Persistent Scatterer interferometry makes deformation measurement on permanent scattering location for the targeted ground surface. Mainly, these permanent scatterer are manmade features like metallic bridges, dams, antennae roof of buildings etc. apart that some permanent scatterer may comprise of prominent stable natural targets. The results obtained from PS-InSAR gives more precised measurement of surface deformation. Total eight ALOS PALSAR scenes covering the time period from 2007 to 2010 have been utilized to produce ground deformation map using PSInSAR techniques for Jharia Coal field, Dhanbad. This is proven technique, which helps to identify the persistent land surface movement .The results were analyzed Sijua area in Jharia coalfield. The subsidence fringes were demarcated over the entire study area. The PSInSAR results were validated using precision leveling data provided by mining authorities. The results demonstrates that PSInSAR can be used as potential tool to highlight the subsidence prone area depending upon the spatial and temporal coherency of SAR data.

  5. Deep Structure and Subsidence of Parnaíba Cratonic Basin, NE Brazil

    Science.gov (United States)

    Rodríguez Tribaldos, V.; White, N. J.; Coelho, D. L. O.; Julià, J.

    2016-12-01

    Cratonic basins are typically underlain by thick lithosphere and slowly subside over hundreds of millions of years. Their stratigraphy consist of unconformity-bounded sequences of continental and shallow marine sedimentary rocks. The origin and evolution of these basins remain enigmatic. Here, we address this problem by carrying out an integrative study of the Parnaíba cratonic basin in NE Brazil. We analyse a 1400 km long deep seismic reflection profile crossing the basin, teleseismic earthquakes recorded by 9 broadband and 10 short-period, 3 component seismometers, 25 ancillary seismic reflection profiles, and 46 wells distributed throughout the basin. Our aim is to constrain subsidence histories in the context of crustal structure and basin architecture. Combined interpretation of the deep seismic profile and 1D velocity models calculated by joint inversion of receiver functions and surface wave dispersion curves locates the Moho at 39 km beneath the city of Teresina on the basin's eastern region. At the eastern edge of the basin, the Moho lies at 37 km beneath Precambrian basement. In the centre of the basin, the Moho lies at 37 km. Beneath Teresina, an increase in S wave velocity at 30 km coincides with mid-crustal reflections on the deep seismic profile. This feature is interpreted as the top of a high-velocity body within the crust. Ancillary seismic profiles show that the stratigraphy is divisible into packages of undisturbed reflections separated by bright, rugged reflections that resemble buried paleolandscapes. Correlation of seismic profiles with well logs shows that these surfaces are basin-wide erosional unconformities that are observable in outcrop. Backstripped and water-loaded subsidence curves show exponential decrease in subsidence over the last 400 Ma. This background subsidence is punctuated by departures from the long-term trend at times when unconformities occur, which we interpret as mild regional uplift events.

  6. Rapid pulses of uplift, subsidence, and subduction erosion offshore Central America: Implications for building the rock record of convergent margins

    Digital Repository Service at National Institute of Oceanography (India)

    Vannucchi, P.; Sak, P.B.; Morgan, J.P.; Ohkushi, K.; Ujiie, K.; IODP Expedition 334 Shipboard Scientists; Yatheesh, V.

    at convergent margins. It currently occurs at roughly one-half of Earth’s subduction zones (von Huene and Scholl, 1991; Clift and Vannucchi, 2004), accounting for one-third of the ~5.25 km3 of continental crust consumed annually (Stern, 2011). It also plays...., Leandro, G., Schulze, A., and Dañobeitia, J.J., 1998, Seismic wideangle investigations in Costa Rica—A crustal velocity model from the Pacifi c to the Caribbean: Zentralblatt für Geologie und Paläontologie, v. 1, p. 393–408. Stern, C.R., 2011...

  7. Magnitude and extent of land subsidence in central Mexico revealed by regional InSAR ALOS time-series survey

    Science.gov (United States)

    Chaussard, E.; Wdowinski, S.; Amelung, F.; Cabral-Cano, E.

    2013-05-01

    Massive groundwater extraction is very common in Mexico and is well known to result in land subsidence. However, most surveys dedicated to land subsidence focus on one single city, mainly Mexico City, and thus fail to provide a comprehensive picture of the problem. Here we use a space-based radar remote sensing technique, known as Interferometric Synthetic Aperture Radar (InSAR) to detect land subsidence in the entire central Mexico area. We used data from the Japanese satellite ALOS, processed over 600 SAR images acquired between 2007-2011 and produced over 3000 interferograms to cover and area of 200,000 km2 in central Mexico. We identify land subsidence in twenty-one areas, including seventeen cities, namely from east to west, Puebla, Mexico city, Toluca de Lerdo, Queretaro, San Luis de la Paz, south of San Luis de la Paz, Celaya, south of Villa de Reyes, San Luis Potosi, west of Villa de Arista, Morelia, Salamanca, Irapuato, Silao, Leon, Aguascalientes, north of Aguascalientes, Zamora de Hidalgo, Guadalajara, Ahuacatlan, and Tepic. Subsidence rates of 30 cm/yr are observed in Mexico City, while in the other locations typical rates of 5-10 cm/yr are noticed. Regional surveys of this type are necessary for the development of hazard mitigation plans and efficient use of ground-based monitoring. We additionally correlate subsidence with land use, surface geology, and faults distribution and suggest that groundwater extraction for agricultural, urban, and industrial uses are the main causes of land subsidence. We also reveal that the limits of the subsiding areas often correlate with existing faults, motion on these faults being driven by water extraction rather than by tectonic activity. In all the subsiding locations we observe high ground velocity gradients emphasizing the significant risks associated with land subsidence in central Mexico. Averaged 2007-2011 ground velocity map from ALOS InSAR time-series in central Mexico, revealing land subsidence in 21

  8. Time series analysis of Mexico City subsidence constrained by radar interferometry

    Science.gov (United States)

    Doin, Marie-Pierre; Lopez-Quiroz, Penelope; Yan, Yajing; Bascou, Pascale; Pinel, Virginie

    2010-05-01

    In Mexico City, subsidence rates reach up to 40 cm/yr mainly due to soil compaction led by the over exploitation of the Mexico Basin aquifer. The Mexico Valley, an endoreic basin surrounded by mountains, was in the past covered by large lakes. After the Spanish conquest, the lakes have almost completely disappeared, being progressively replaced by buildings of the current Mexican capital. The simplified hydrogeologic structure includes a superficial 50 to 300 m thick lacustrine aquitard overlying a thicker aquifer made of alluvial deposits. The aquitard layer plays a crucial role in the subsidence process due to the extremely high compressibility of its clay deposits separated by a less compressible sand layer where the biggest buildings of the city are anchored. The aquifer over-exploitation leads to a large scale 30m depression of its piezometric level, inducing water downwards flow in the clays, yielding compaction and subsidence. In order to quantitatively link subsidence to water pumping, the Mexico city subsidence needs to be mapped and analyzed through space and time. We map its spatial and temporal patterns by differential radar interferometry, using 38 ENVISAT images acquired between end of 2002 and beginning of 2007. We employ both a Permanent Scatterer (PS) and a small baseline (SBAS) approach. The main difficulty consists in the severe unwrapping problems mostly due to the high deformation rate. We develop a specific SBAS approach based on 71 differential interferograms with a perpendicular baseline smaller than 500 m and a temporal baseline smaller than 9 months, forming a redundant network linking all images: (1) To help the unwrapping step, we use the fact that the deformation shape is stable for similar time intervals during the studied period. As a result, a stack of the five best interferograms can be used to reduce the number of fringes in wrapped interferograms. (2) Based on the redundancy of the interferometric data base, we quantify the

  9. Land subsidence, structures and processes at the Dead Sea shoreline as revealed by a near-field photogrammetry survey at Ghor Haditha, Jordan

    Science.gov (United States)

    Al-Halbouni, Djamil; Holohan, Eoghan P.; Walter, Thomas; Alrshdan, Hussam; Sawarieh, Ali; Dahm, Torsten

    2015-04-01

    Rapid recession of the Dead Sea in the last few decades has led to an increasing rate of sinkhole formation around the lake shore. The development of these sinkholes and other land subsidence phenomena poses a major geological hazard to the local population, agriculture and industry. For a better understanding of the underlying physical processes and for determining current and future areas of sinkhole hazard, we conducted field investigations and a first low altitude ("near-field") aerial photogrammetric survey with a Helikite Balloon at Ghor Haditha, Jordan, in October 2014. From the near-field photogrammetry, we generated a high resolution Digital Elevation Model of the surveyed area. This enables a detailed quantification of sinkhole sizes and distribution as well of morphological parameters such as the sinkhole depth/diameter ratio (D). Values of the latter are generally greater in the mechanically stronger alluvial fan sediments (D = 3.0 - 0.4) than in the weaker muds of the former Dead Sea lakebed (D = 0.3 - 0.1). Importantly, the point of emanation of a very recent and sediment-laden stream at c. 10m below the former floor of the Dead Sea can be structurally and morphologically connected to the main sinkhole area. This provides evidence for channelised subterranean groundwater flows beneath this area. From our observations, two processes were identified as key factors for the development of large land subsidence structures and local sinkhole clusters: (1) Subrosion of weak material due to groundwater following preferred flow paths of ancient and current wadi riverbeds and (2) rapid dissolution of soluble material (salt) in this aragonite-rich mud. The heterogeneous geology and alternation of aquifers (alluvial fan sediments) and aquicludes (mud-flats) lead to the formation of complex subsurface flow channels that represent the secondary porosity of the internal structure of karst aquifers. As a consequence of these subterranean channels, local bending and

  10. Effects of anthropogenic land-subsidence on inundation dynamics: the case study of Ravenna, Italy

    Directory of Open Access Journals (Sweden)

    F. Carisi

    2016-05-01

    Full Text Available Can differential land-subsidence significantly alter river flooding dynamics, and thus flood risk in flood prone areas? Many studies show how the lowering of the coastal areas is closely related to an increase in the flood-hazard due to more important tidal flooding and see level rise. The literature on the relationship between differential land-subsidence and possible alterations to riverine flood-hazard of inland areas is still sparse, although several geographical areas characterized by significant land-subsidence rates during the last 50 years experienced intensification in both inundation magnitude and frequency. We investigate the possible impact of a significant differential ground lowering on flood hazard over a 77 km2 area around the city of Ravenna, in Italy. The rate of land-subsidence in the study area, naturally in the order of a few mm year−1, dramatically increased up to 110 mm year−1 after World War II, primarily due to groundwater pumping and gas production platforms. The result was a cumulative drop that locally exceeds 1.5 m. Using a recent digital elevation model (res. 5 m and literature data on land-subsidence, we constructed a ground elevation model over the study area in 1897 and we characterized either the current and the historical DEM with or without road embankments and land-reclamation channels in their current configuration. We then considered these four different topographic models and a two-dimensional hydrodynamic model to simulate and compare the inundation dynamics associated with a levee failure scenario along embankment system of the river Montone, which flows eastward in the southern portion of the study area. For each topographic model, we quantified the flood hazard in terms of maximum water depth (h and we compared the actual effects on flood-hazard dynamics of differential land-subsidence relative to those associated with other man-made topographic alterations, which resulted to be much

  11. Evaluation of subsidence hazard in mantled karst setting: a case study from Val d'Orléans (France)

    Science.gov (United States)

    Perrin, Jérôme; Cartannaz, Charles; Noury, Gildas; Vanoudheusden, Emilie

    2015-04-01

    Soil subsidence/collapse is a major geohazard occurring in karst region. It occurs as suffosion or dropout sinkholes developing in the soft cover. Less frequently it corresponds to a breakdown of karst void ceiling (i.e., collapse sinkhole). This hazard can cause significant engineering challenges. Therefore decision-makers require the elaboration of methodologies for reliable predictions of such hazards (e.g., karst subsidence susceptibility and hazards maps, early-warning monitoring systems). A methodological framework was developed to evaluate relevant conditioning factors favouring subsidence (Perrin et al. submitted) and then to combine these factors to produce karst subsidence susceptibility maps. This approach was applied to a mantled karst area south of Paris (Val d'Orléans). Results show the significant roles of the overburden lithology (presence/absence of low-permeability layer) and of the karst aquifer piezometric surface position within the overburden. In parallel, an experimental site has been setup to improve the understanding of key processes leading to subsidence/collapse and includes piezometers for measurements of water levels and physico-chemical parameters in both the alluvial and karst aquifers as well as surface deformation monitoring. Results should help in designing monitoring systems to anticipate occurrence of subsidence/collapse. Perrin J., Cartannaz C., Noury G., Vanoudheusden E. 2015. A multicriteria approach to karst subsidence hazard mapping supported by Weights-of-Evidence analysis. Submitted to Engineering Geology.

  12. Effect of external digital elevation model on monitoring of mine subsidence by two-pass differential interferometric synthetic aperture radar

    Science.gov (United States)

    Tao, Qiuxiang; Gao, Tengfei; Liu, Guolin; Wang, Zhiwei

    2017-04-01

    The external digital elevation model (DEM) error is one of the main factors that affect the accuracy of mine subsidence monitored by two-pass differential interferometric synthetic aperture radar (DInSAR), which has been widely used in monitoring mining-induced subsidence. The theoretical relationship between external DEM error and monitored deformation error is derived based on the principles of interferometric synthetic aperture radar (DInSAR) and two-pass DInSAR. Taking the Dongtan and Yangcun mine areas of Jining as test areas, the difference and accuracy of 1:50000, ASTER GDEM V2, and SRTM DEMs are compared and analyzed. Two interferometric pairs of Advanced Land Observing Satellite Phased Array L-band SAR covering the test areas are processed using two-pass DInSAR with three external DEMs to compare and analyze the effect of three external DEMs on monitored mine subsidence in high- and low-coherence subsidence regions. Moreover, the reliability and accuracy of the three DInSAR-monitored results are compared and verified with leveling-measured subsidence values. Results show that the effect of external DEM on mine subsidence monitored by two-pass DInSAR is not only related to radar look angle, perpendicular baseline, slant range, and external DEM error, but also to the ground resolution of DEM, the magnitude of subsidence, and the coherence of test areas.

  13. Numerical analysis to determine the impact of land subsidence on high-speed railway routes in Beijing, China

    Directory of Open Access Journals (Sweden)

    C. Ye

    2015-11-01

    Full Text Available More than 10 high-speed railway routes with top speeds of 300 km h−1 are expected to be operational from Beijing by the year 2020. However, the safety of these routes is affected by the occurrence of land subsidence. This paper focuses on the Beijing–Tianjin Intercity High-Speed Railway (BTR, the first high-speed railway in China, to analyze the operational safety of high-speed railway routes by analyzing both regional land subsidence and local differential subsidence caused by groundwater drawing. The Beijing construction stratum is mainly composed of cohesive soil, and the BTR has a maximum accumulative subsidence of > 800 mm and a maximum subsidence rate of > 80 mm a−1. In this paper, finite-element software ABAQUS is used to analyze groundwater drawdown and land subsidence caused by local water drawing, and its effect on the bearing capacity of railway bridge pile foundations and the orbit concrete supporting course. The analysis provides a technical basis for developing prevention and control engineering measures against land subsidence so as to guarantee the safe operation of these high-speed railway routes.

  14. BasinVis 1.0: A MATLAB®-based program for sedimentary basin subsidence analysis and visualization

    Science.gov (United States)

    Lee, Eun Young; Novotny, Johannes; Wagreich, Michael

    2016-06-01

    Stratigraphic and structural mapping is important to understand the internal structure of sedimentary basins. Subsidence analysis provides significant insights for basin evolution. We designed a new software package to process and visualize stratigraphic setting and subsidence evolution of sedimentary basins from well data. BasinVis 1.0 is implemented in MATLAB®, a multi-paradigm numerical computing environment, and employs two numerical methods: interpolation and subsidence analysis. Five different interpolation methods (linear, natural, cubic spline, Kriging, and thin-plate spline) are provided in this program for surface modeling. The subsidence analysis consists of decompaction and backstripping techniques. BasinVis 1.0 incorporates five main processing steps; (1) setup (study area and stratigraphic units), (2) loading well data, (3) stratigraphic setting visualization, (4) subsidence parameter input, and (5) subsidence analysis and visualization. For in-depth analysis, our software provides cross-section and dip-slip fault backstripping tools. The graphical user interface guides users through the workflow and provides tools to analyze and export the results. Interpolation and subsidence results are cached to minimize redundant computations and improve the interactivity of the program. All 2D and 3D visualizations are created by using MATLAB plotting functions, which enables users to fine-tune the results using the full range of available plot options in MATLAB. We demonstrate all functions in a case study of Miocene sediment in the central Vienna Basin.

  15. SAR Inteferometry and GPS Surveying for Subsidence Monitoring and its Contribution to Risk Management, the Case Study of Aguascalientes, Mexico

    Science.gov (United States)

    Esquivel, R.; Castaneda, L. P.

    2013-05-01

    Aguascalientes valley is just one of many regions affected by ground subsidence in Mexico, results of GPS monitoring from 2003 to date and differential SAR interferometry using Envisat archived data show subsidence maximums of 15 centimeters but with a decreasing rate with time. Recent implementation of TerraSAR-X stripmap mode images allowed a more accurate estimation of displacements, which are being used for subsidence mapping and to develop models for corrections to geodetic positions. In addition, results of the study are also being used to the development of the State's atlas of hazards and will contribute by detecting new ground failures and areas susceptible to failure.

  16. Early Paleozoic paleogeography of Laurentia and western Gondwana: Evidence from tectonic subsidence analysis

    Science.gov (United States)

    Williams, Kenneth E.

    1997-08-01

    A number of terranes were present in the early Paleozoic ocean between Laurentia and Gondwana following rifting. The precise location of these microcontinents and island arcs is unclear. We present tectonic subsidence curves from selected basins that may provide some constraints on the possible paleogeographic interpretations for this time interval. Among these tectonic blocks were the Precordillera terrane that originated in the Ouachita area of Laurentia and the composite Avalon-Carolina terrane that was derived from the Gondwana margin. Also present were the island-arc terranes of Famatina, Mixteca, and Zapoteca. The Precordillera and Famatina terranes are currently located in southern South America. The Avalon-Carolina terrane is in eastern North America. The Mixteca and Zapoteca terranes are in Central America. A review of previous work augmented by new tectonic subsidence analysis indicates that these terranes were swept up by early Paleozoic plate movements and were translated to approximately their present relative positions by the Early Carboniferous.

  17. ORGANIZATION AND RESULTS OF AGRICULTURAL HOLDINGS REALIZING INVESTMENTS SUBSIDIZED WITH PUBLIC FUNDS

    Directory of Open Access Journals (Sweden)

    Zofia Kołoszko-Chomentowska

    2016-03-01

    Full Text Available In the present article, an attempt was made to assess the organization of production and economic results of agricultural holdings that realized investments subsidized with public funds, from the perspective of good agricultural practice. Agricultural holdings in the Podlaskie voivodeship registered in the FADN system in 2011–2012 were investigated. Assessment accounted for crop structure, stock density, production intensity, the value and structure of capital, and profi tableness of land, capital, and labour. Analysis showed that holdings benefi ting from subsidization of investments with public funds were characterized by greater production intensity and also achieved better economic results. However, they exerted greater pressure on the environment and posed hazards that mainly resulted from high stock density.  

  18. Subsidizing solar energy: the role of tax credits, loans, and warranties

    Energy Technology Data Exchange (ETDEWEB)

    Berman, S.M.; Fisher, A.C.

    1978-03-01

    It is generally agreed that solar energy is an appropriate technology. It is further agreed that its use ought to be subsidized by appropriate governmental action. There is not, however, a consensus as to just why solar energy is desirable, or what constitutes appropriate action. In this paper some arguments are considered for a subsidy and are related to a specific proposal. First, some of the arguments that have been advanced in favor of subsidizing solar energy are reviewed. Next, an additional argument, which seems to offer a strong rationale for a subsidy of a somewhat unconventional sort--a government-backed service warranty--is proposed. Then the argument for the warranty is presented, along with an argument for a subsidy to overcome high front-end costs. Finally, some estimates of the budget costs of a warranty program are presented.

  19. Steady subsidence of a repeatedly erupting caldera through InSAR observations: Aso, Japan

    KAUST Repository

    Nobile, Adriano

    2017-04-05

    The relation between unrest and eruption at calderas is still poorly understood. Aso caldera, Japan, shows minor episodic phreatomagmatic eruptions associated with steady subsidence. We analyse the deformation of Aso using SAR images from 1993 to 2011 and compare it with the eruptive activity. Although the dataset suffers from limitations (e.g. atmospheric effects, coherence loss, low signal-to-noise ratio), we observe a steady subsidence signal from 1996 to 1998, which suggests an overall contraction of a magmatic source below the caldera centre, from 4 to 5 km depth. We propose that the observed contraction may have been induced by the release of the magmatic fluids feeding the eruptions. If confirmed by further data, this hypothesis suggests that degassing processes play a crucial role in triggering minor eruptions within open conduit calderas, such as at Aso. Our study underlines the importance of defining any eruptive potential also from deflating magmatic systems with open conduit.

  20. Imprint of salt tectonics on subsidence patterns during rift to post-rift transition: The Central High Atlas case study

    Science.gov (United States)

    Moragas, Mar; Vergés, Jaume; Saura, Eduard; Diego Martín-Martín, Juan; Messager, Grégoire; Hunt, David William

    2017-04-01

    During Mesozoic time, the extensional basin of the Central High Atlas in Morocco underwent two consecutive rifting events: Permo-Triassic and Early-Middle Jurassic in age. However, a review of the literature reveals that the precise timing of the Early-Middle Jurassic rift and post-rift transition varies depending of the analysed area. The discrepancy about rifting ages is associated with the general lack of normal faulting cutting post-Lower Jurassic strata and the presence of significant salt diapiric activity during Early and Middle Jurassic in the central part of the basin. To evaluate the influence on subsidence patterns of the interaction between both extensional and salt tectonics, we present new subsidence data from diverse paleogeographic and tectonic settings of the Central High Atlas rift basin. From the periphery of the basin, the Djebel Bou Dahar platform-basin system corresponds to a shallow carbonate platform developed on top of a basement high, controlled and bounded by normal faults. The results of the subsidence analysis show long-term and low-rate of tectonic and total subsidence (0.06 and 0.08 mmyr-1 respectively). The roughly parallel evolution of both total and tectonic subsidence curves indicates the tectonic influence of the platform-basin system, as corroborated by the syndepositional fault activity of the outcropping Sinemurian-Pliensbachian normal faults. Contrarily, the rift axis is characterised by the presence of diapiric salt ridges and minibasins as in the Tazoult-Amezraï area and Imilchil diapiric province. Comparison between subsidence curves from the SE flank of the Tazoult salt wall and from Amezraï minibasin centre shows that, from Pliensbachian to Aalenian, the tectonic and total subsidence rates of the Amezraï minibasin (between 0.17-0.32 mmyr-1 and 0.38-0.98 mmyr-1) are two-fold their equivalent rates in the Tazoult salt wall. Amezraï minibasin values are in agreement with the values from Imilchil minibasins (tectonic and

  1. Rapid Prototyping

    Science.gov (United States)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  2. North Atlantic-Arctic circulation controlled by the subsidence history of the Greenland-Scotland Ridge

    OpenAIRE

    Stärz, Michael; Jokat, Wilfried; Knorr, Gregor; Lohmann, Gerrit

    2016-01-01

    Changes in high latitude ocean gateways and CO2 are thought to be main drivers of Cenozoic climate evolution. However, the link between global climate changes and the early ocean gateway formation between the North Atlantic and the Arctic Ocean (incl. the Greenland and Norwegian Seas) controlled by the subsidence of the Greenland-Scotland Ridge is poorly understood. Here, we use a coupled ocean–atmosphere general circulation model for Oligocene-Miocene boundary conditions to address the venti...

  3. Time-varying land subsidence detected by radar altimetry: California, Taiwan and north China

    OpenAIRE

    Hwang, Cheinway; Yang, Yuande; Kao, Ricky; Han, Jiancheng; Shum, C. K.; Galloway, Devin L.; Sneed, Michelle; Hung, Wei-Chia; Cheng, Yung-Sheng; Li, Fei

    2016-01-01

    Contemporary applications of radar altimetry include sea-level rise, ocean circulation, marine gravity, and icesheet elevation change. Unlike InSAR and GNSS, which are widely used to map surface deformation, altimetry is neither reliant on highly temporally-correlated ground features nor as limited by the available spatial coverage, and can provide long-term temporal subsidence monitoring capability. Here we use multi-mission radar altimetry with an approximately 23 year data-span to quantify...

  4. InSAR data for monitoring land subsidence: time to think big

    OpenAIRE

    Ferretti, A.; Colombo, D.; Fumagalli, A; Novali, F.; Rucci, A.

    2015-01-01

    Satellite interferometric synthetic aperture radar (InSAR) data have proven effective and valuable in the analysis of urban subsidence phenomena based on multi-temporal radar images. Results obtained by processing data acquired by different radar sensors, have shown the potential of InSAR and highlighted the key points for an operational use of this technology, namely: (1) regular acquisition over large areas of interferometric data stacks; (2) use of advanced processing alg...

  5. Analysis of summer subsidence in Barrow, Alaska, using InSAR and hyperspectral remote sensing

    OpenAIRE

    Mahmud Haghshenas Haghighi; M. Motagh; B. Heim; S. Chabrillat; D. Streletskiy; G. Grosse; T. Sachs; Katrin Kohnert

    2016-01-01

    In this study, gradual elevation change due to summer thawing of active layer in tundra permafrost landscape of Barrow, Alaska is investigated using SAR interferometry (InSAR) technique. We used a variety of SAR sensors including TerraSAR-X, ALOS, and Sentinel-1 images to assess elevation changes in summer season. Preliminary result, obtained by TerraSAR-X InSAR analysis, clearly delineates subsidence during the summer by identifying thousands of coherent pixels on ...

  6. Post-orogenic subsidence and uplift of the Carpathian belt: An integrated approach

    Science.gov (United States)

    Bertotti, G.; Matenco, L.; Drijkonigen, G.; Krijgsman, W.; Tarapoanca, M.; Panea, I.; Vasiliev, I.; Milea, M.; Cloetingh, S.

    2003-04-01

    Several hundred metres thick Pliocene to Quaternary sequences outcropping along the Carpathian front steeply dip away from the mountain belt towards the Carpathian foredeep. They overly the Carpathian fold-and-thrust belt and document that, following the main contractional stages, the orogenic wedge first subsided and was then uplifted. Uplift occurred coeval with substantial subsidence in the basin adjacent to the E, the Focsani Depression. To define the precise kinematics of such movements and thereby constrain these vertical movements taking place in the "wrong" place and in the "wrong" time, the Netherlands Research Center for Integrated Solid Earth Science has launched a large campaign of geological and geophysical investigation. The main components of the project are as follows: 1) acquisition of nearly 100km of seismic data designed to image the uppermost hundred metres of the Earth's crust and thereby making a precise connection between features visible in Industry lines and at the surface 2) paleomagnetic investigations in order to constrain the age of the poorly dated continental to lacustrine sediments 3) A seismic experiment designed to detect 3-D effects on 2-D acquisition 4) Structural work to determine the stress/strain conditions during subsidence and subsequent uplift At a larger scale, these activities are embedded in the effort made by ISES and connected groups to precisely constrain the kinematics of the Pannonian-Carpathian system. Seismic acquisition has been performed during the summer 2002 and has been technically very successful thanks also to the effort of the prospecting company Prospectiunii SA. Lines have been processed and are currently being interpreted. The most apparent feature is the lack of localized deformation demonstrating that subsidence and tilting affected areas of several tens of kilometers and are not related to single faults. Sampling for paleomagnetic studies has been carried out in 2002 along the same section where

  7. Subsidence monitoring system for offshore applications: technology scouting and feasibility studies

    Science.gov (United States)

    Miandro, R.; Dacome, C.; Mosconi, A.; Roncari, G.

    2015-11-01

    Because of concern about possible impacts of hydrocarbon production activities on coastal-area environments and infrastructures, new hydrocarbon offshore development projects in Italy must submit a monitoring plan to Italian authorities to measure and analyse real-time subsidence evolution. The general geological context, where the main offshore Adriatic fields are located, is represented by young unconsolidated terrigenous sediments. In such geological environments, sea floor subsidence, caused by hydrocarbon extraction, is quite probable. Though many tools are available for subsidence monitoring onshore, few are available for offshore monitoring. To fill the gap ENI (Ente Nazionale Idrocarburi) started a research program, principally in collaboration with three companies, to generate a monitoring system tool to measure seafloor subsidence. The tool, according to ENI design technical-specification, would be a robust long pipeline or cable, with a variable or constant outside diameter (less than or equal to 100 mm) and interval spaced measuring points. The design specifications for the first prototype were: to detect 1 mm altitude variation, to work up to 100 m water depth and investigation length of 3 km. Advanced feasibility studies have been carried out with: Fugro Geoservices B.V. (Netherlands), D'Appolonia (Italy), Agisco (Italy). Five design (using three fundamental measurements concepts and five measurement tools) were explored: cable shape changes measured by cable strain using fiber optics (Fugro); cable inclination measured using tiltmeters (D'Appolonia) and measured using fiber optics (Fugro); and internal cable altitude-dependent pressure changes measured using fiber optics (Fugro) and measured using pressure transducers at discrete intervals along the hydraulic system (Agisco). Each design tool was analysed and a rank ordering of preferences was performed. The third method (measurement of pressure changes), with the solution proposed by Agisco, was

  8. Assessment of radar interferometry performance for ground subsidence monitoring due to underground mining

    Energy Technology Data Exchange (ETDEWEB)

    Ng, A.H.M.; Chang, H.C.; Ge, L.L.; Rizos, C.; Omura, M. [Cooperative Research Centre for Spatial Information, Carlton, Vic. (Australia)

    2009-07-01

    This paper describes the results from the recently launched SAR satellites for the purpose of subsidence monitoring over underground coal mine sites in the state of New South Wales, Australia, using differential interferometric synthetic aperture radar (DInSAR) technique. The quality of the mine subsidence monitoring results is mainly constrained by noise due to the spatial and temporal decorrelation between the interferometric pair and the phase discontinuities in the interferogram. This paper reports oil the analysis of the impact of these two factors on the performance of DInSAR for monitoring ground deformation. Simulations were carried out prior to real data analyses. SAR data acquired using different operating frequencies, for example, X-, C- and L-band, from the TerraSAR-X, ERS-1/2, ENVISAT, JERS-1 and ALOS satellite missions, were examined. The simulation results showed that the new satellites ALOS, TerraSAR-X and COSMO-SkyMed perform much better than the satellites launched before 2006. ALOS and ENVISAT satellite SAR images with similar temporal coverage were searched for the test site. The ALOS PALSAR DInSAR results have been compared to DInSAR results obtained from ENVISAT ASAR data to investigate the performance of both satellites for ground subsidence monitoring. Strong phase discontinuities and decorrelation have been observed in almost all ENVISAT interferograms and hence it is not possible to generate the displacement maps without errors. However these problems are minimal in ALOS PALSAR interferograms due to its spatial resolution and longer wavelength. Hence ALOS PALSAR is preferred for ground subsidence monitoring in areas covered by vegetation and where there is a high rate ground deformation.

  9. Subsidence due to fluid withdrawal: a survey of analytical capabilities. [1225 citations

    Energy Technology Data Exchange (ETDEWEB)

    Engi, D.

    1985-08-01

    An extensive review of the literature was conducted in the area of land subsidence due to the withdrawal of fluids. A method of categorizing the citations was developed to facilitate identification of references relating to specific fields of interest. A brief review of the materials represented by the bibliography indicates the state-of-the-art within this area. The bibliography (containing 1225 citations) is presented in its categorized form. 5 figs., 3 tabs.

  10. MULTI BAND INSAR ANALYSIS OF SUBSIDENCE DEVELOPMENT BASED ON THE LONG PERIOD TIME SERIES

    Directory of Open Access Journals (Sweden)

    F. C. Çomut

    2015-12-01

    Full Text Available The SAR Interferometry (InSAR application has shown great potential in monitoring of land terrain changes and in detection of land deformations such as subsidence. Longer time analysis can lead to understand longer trends and changes. Using different bands of SAR satellite (C- from ERS 1-2 and Envisat, L- from ALOS over the study area, we achieve knowledge of movements in long-term and evaluation of its dynamic changes within observed period of time. Results from InSAR processing fit with the position changes in vertical direction based on GPS network established over the basin as an effective geodetic network. Time series (StaMPS PS+SB of several points over Çumra County in eastern part of Konya City show a general trend of the deformation that is expected to be approximately between -13 to -17 mm/year. Northern part of Karaman is affected by faster subsidence, borders of the subsidence trough were identified from Envisat. Presenting InSAR results together with GIS information about locations and time of occurrence of sudden subsidence, urban/industrial growth in time and climate changes helps in better understanding of the situation. This way, the impact of natural and man-made changes will be shown for urban planning thanks to InSAR and GIS comparisons with hydrogeological modeling. In this study we present results of differential and multitemporal InSAR series using different bands and GIS conjunction associated with seasonal and temporal groundwater level changes in Konya Closed Basin.

  11. Subsidizing Creativity through Network Design: Zero-Pricing and Net Neutrality

    OpenAIRE

    Robin S. Lee; Tim Wu

    2009-01-01

    This paper focuses on the pricing aspect of the "net neutrality" debate -- in particular, the de facto ban on fees levied by Internet service providers on content providers to reach users. This "zero-price" rule may prove desirable for several reasons. Using a two-sided market analysis, we suggest that it subsidizes creativity and innovation in new content creation -- goals shared by copyright and patent laws. The rule also helps to solve a coordination problem: since Internet service provide...

  12. Characterizing land subsidence mechanisms as a function of urban basin geohazards using space geodesy

    Science.gov (United States)

    Bawden, G. W.

    2016-12-01

    Land subsidence in urban basins will likely become a more significant geohazard in many of the global sedimentary basins as population growth, resource availability, and climate change compound natural and anthropogenic contributors that influence basin elevation. Coastal basins are at the greatest risk where land subsidence is additive to sea level rise, thereby increasing the rate of exposure to coastal populations. Land surface elevation change is a function of many different parameters, including: elastic and inelastic surface response to managed and natural groundwater levels; anthropogenic activities (hydrocarbon extraction, wastewater injection, fracking, geothermal production, and mass redistribution); local tectonic deformation and regional tectonic drivers (such as repeated uplift and subsidence cycles above subduction zones); climate change (influencing the timing, magnitude, nature and duration of seasonal/annual precipitation and permafrost extent); material properties of the basin sediments (influencing susceptibility to soil compaction, oxidization, and dissolution); post glacial rebound; isostatic flexure associated with sea-level and local mass changes; and large scale gravitational processes (such as growth faults and landslides). Geodetic measurements, such as InSAR and GPS, help track spatial and temporal changes in both relative and absolute basin elevation thereby helping to characterize the mechanism(s) driving the geohazards. In addition to a number of commercial radar satellites, European Space Agency's Sentinel-1a/b satellites are beginning to provide a wealth of data over many basin targets with C-band (5.5 cm wavelength). The NISAR (NASA-ISRO Synthetic Aperture Radar) L-band (24 cm wavelength) mission (anticipated 2021 launch) will image nearly every basin globally every 12 days and data from the mission will help characterize land subsidence and many other solid-Earth and hydrologic geohazards that impact urban basins.

  13. [Nutrient spatiotemporal distribution and eutrophication process in subsidence waters of Huainan and Huaibei mining areas, China].

    Science.gov (United States)

    Qu, Xi-Jie; Yi, Qi-Tao; Hu, You-Biao; Yan, Jia-Ping; Yu, Huai-Jun; Dong, Xiang-Lin

    2013-11-01

    A total of eight mining subsidence waters, including five sites in Huainan "Panxie" Mining Areas (PXS-1, PXS-2, PXS-3, PXS-4, and PXS-5) and three sites in Huaibei "Zhu-Yang huang" Mining Areas (HBDH, HBZH, HBNH), were selected to study the nutrient temporal and spatial distribution and trophic states. Among the sites, three sites (PXS-1, PXS-3, and HBDH) showed higher nutrient level and could be classified into moderate eutrophication, whereas the other five were in moderate nutrient level and mild eutrophication. Overall, the nutrient level of Huainan mining subsidence waters was higher than that of Huaibei mining subsidence waters. All the test samples in the two mining areas had a higher ratio of nitrogen to phosphorus (N:P), being 25-117 in Huainan and 17-157 in Huaibei, and with a seasonal variety, the lowest in growth season. The dissolved inorganic phosphorus (DIP) in total phosphorous (TP) occupied a small percentage, being averagely 15.4% and 18.4% in Huainan and Huaibei mining areas, respectively. Nitrate was the main specie of dissolved inorganic nitrogen (DIN), with the ratio of nitrate to DIN being 74% and 89% in Huainan and Huaibei mining areas, respectively. Relative to the waters age, human activities could be one of the main factors responsible for the high nutrient level and the faster eutrophication process of these waters.

  14. Use of Cemented Super-Fine Unclassified Tailings Backfill for Control of Subsidence

    Directory of Open Access Journals (Sweden)

    Lei Yang

    2017-11-01

    Full Text Available Known for its advantages in preventing geological and environmental hazards, cemented paste backfill (CPB has become a topic of interest for scientists and mining engineers in recent decades. This paper presents the results of a study on the use of cemented super-fine tailings backfill (CSUTB in an underground mine for control of surface subsidence. An analytical solution is developed based on the available model to calculate the required strength of backfill when in contact with non-cemented tailings (NCT. The effect of solid contents on the rheological properties of CSUTB is investigated. A reasonable mix proportion (RMP of CSUTB is determined for Zhongguan Iron Mine (ZGIM based on laboratory experiments. The validity of RMP in surface subsidence control is verified by a 3D numerical model. The obtained results show that CSUTB requires higher strength when in contact with NCT than when in contact with orebody. Rheological characteristics, e.g., slump, fluidity, and bleeding rate of fresh CSUTB, decrease with higher solids content, of which values with a certain solids content can be determined by quadratic polynomial regression equations. RMP with a cement to tailings (c/t ratio of 1:10 and a solids content of 70% is recommended for ZGIM, as it shows favorable mechanical and rheological abilities. The deformation parameters (curvature, inclination, and horizontal deformation rate obtained from numerical modeling are acceptable and lower than critical values, meaning CSUTB can feasibly be used with RMP in subsidence control.

  15. Seismic fragility formulations for segmented buried pipeline systems including the impact of differential ground subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Pineda Porras, Omar Andrey [Los Alamos National Laboratory; Ordaz, Mario [UNAM, MEXICO CITY

    2009-01-01

    Though Differential Ground Subsidence (DGS) impacts the seismic response of segmented buried pipelines augmenting their vulnerability, fragility formulations to estimate repair rates under such condition are not available in the literature. Physical models to estimate pipeline seismic damage considering other cases of permanent ground subsidence (e.g. faulting, tectonic uplift, liquefaction, and landslides) have been extensively reported, not being the case of DGS. The refinement of the study of two important phenomena in Mexico City - the 1985 Michoacan earthquake scenario and the sinking of the city due to ground subsidence - has contributed to the analysis of the interrelation of pipeline damage, ground motion intensity, and DGS; from the analysis of the 48-inch pipeline network of the Mexico City's Water System, fragility formulations for segmented buried pipeline systems for two DGS levels are proposed. The novel parameter PGV{sup 2}/PGA, being PGV peak ground velocity and PGA peak ground acceleration, has been used as seismic parameter in these formulations, since it has shown better correlation to pipeline damage than PGV alone according to previous studies. By comparing the proposed fragilities, it is concluded that a change in the DGS level (from Low-Medium to High) could increase the pipeline repair rates (number of repairs per kilometer) by factors ranging from 1.3 to 2.0; being the higher the seismic intensity the lower the factor.

  16. On the possible contribution of clayey inter-layers to delayed land subsidence above producing aquifers

    Science.gov (United States)

    Isotton, G.; Ferronato, M.; Gambolati, G.; Teatini, P.

    2015-11-01

    In recent years, measurements of land subsidence above pumped aquifers by permanent GPS and InSAR have exhibited some delay relative to drawdown ranging from months to years. The current modeling approaches accounting for water fluid dynamics and porous medium geomechanics may fail to predict such a delay and may underestimate the land settlement after the well shutdown. In the present communication, an investigation is made on the residual compaction of the intervening clayey formations as a possible contribution to retarded land subsidence. The pore pressure variation within the aquifer and its propagation in the clay are simulated by a finite element flow model, with the resulting pore pressure decline used as input data in a hypo-plastic geomechanical model. A proper sensitivity analysis on (i) aquifer depth, (ii) ratio between the sandy and the clayey layers thickness and hydraulic conductivity, (iii) oedometric compressibility in first and second loading cycles, is performed for a typical geology of a Quaternary sedimentary basin. The results show that a certain fraction, up to 20 % of the overall land subsidence, can take place after the shutdown of the producing wells depending on actual basin, litho-stratigraphy and parameter values.

  17. Radar Interferometry Techniques for Monitoring Subsidence Induced by Excessive Goundwater Pumping in Crete, Greece

    Science.gov (United States)

    Mertikas, S. P.; Papadaki, E. S.; Paleologos, Ev.

    2010-12-01

    Extensive exploitation of the groundwater at the Messara valley, Crete, Greece has lead to a 40-meter decrease in the level of water over the last 20 years. Land subsidence seem to result out of this activity. This investigation aims at mapping ground subsidence possibly induced by excessive ground water pumping using differential interferometry. A total of 29 ERS-1 & 2 SAR and 6 ALOS PALSAR images have been used for forming interferograms. The used images covered the period from 1992 to 2000 and 2007-2010, respectively. The Shuttle Radar Terrain Mission, with 90-m pixel size and ±16 m absolute height accuracy, has been incorporated in the interferometric processing. Atmospheric artifacts have been compensated by image stacking. The ERS C- band (5.6 cm) could not overcome the problem of coherence loss due to ground moisture as a result of irrigation and dense cultivation in the area. On the other hand, processing of ALOS L-band (23.4 cm) data has revealed a ground subsidence that amounted to at least 2 cm/yr for the period 2007-2010. The correlation of the observed ground deformation with water pumping and other geological parameters has also been investigated.

  18. An Improved Adaptive Template Size Pixel-Tracking Method for Monitoring Large-Gradient Mining Subsidence

    Directory of Open Access Journals (Sweden)

    Jilei Huang

    2017-01-01

    Full Text Available The monitoring of large-gradient deformation caused by coal mining is of great significance to the prevention and management of disasters in mining areas. The interferometric synthetic aperture radar (InSAR method captures the small-gradient ground deformation on the edge of the subsidence basin accurately but is unreliable for capturing large-gradient deformation. The intensity-based pixel-tracking method (e.g., the normalized cross-correlation (NCC method can overcome the limitations of InSAR’s maximum detectable displacement gradient and incoherence. However, the pixel-tracking method is sensitive to template size. It is difficult to estimate ground subsidence accurately by the conventional pixel-tracking method with fixed template size. In this paper, the signal-to-noise ratio (SNR is redefined and an improved locally adaptive template size method is proposed by identifying optimal template adaptively based on maximization of the redefined SNR. The constraint radius is used to constrain the search area in this improved method. The frequency of misrepresentation is reduced by finding the peak of the correlation coefficient surface within the search area. Both simulation data and real ground subsidence data are used to test this algorithm. The results show that this method can improve monitoring accuracy compared with the traditional pixel-tracking method for fixed template size.

  19. Numerical and experimental study of strata behavior and land subsidence in an underground coal gasification project

    Directory of Open Access Journals (Sweden)

    N. N. Sirdesai

    2015-11-01

    Full Text Available Underground Coal Gasification, with enhanced knowledge of hydrogeological, geomechanical and environmental aspects, can be an alternative technique to exploit the existing unmineable reserves of coal. During the gasification process, petro-physical and geomechanical properties undergo a drastic change due to heating to elevated temperatures. These changes, caused due to the thermal anisotropy of various minerals, result in the generation of thermal stresses; thereby developing new fracture pattern. These fractures cause the overhead rock strata to cave and fill the gasification chamber thereby causing subsidence. The degree of subsidence, change in fluid transport and geomechanical properties of the rock strata, in and around the subsidence zone, can affect the groundwater flow. This study aims to predict the thermo-geomechanical response of the strata during UCG. Petro-physical and geomechanical properties are incorporated in the numerical modelling software COMSOL Multiphysics and an analytical strength model is developed to validate and further study the mechanical response and heat conduction of the host rock around the gasification chamber. Once the problems are investigated and solved, the enhanced efficiency and the economic exploitation of gasification process would help meet country's energy demand.

  20. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TONWSHIP, NEW JERSEY

    Energy Technology Data Exchange (ETDEWEB)

    Gary Gartenberg

    2003-02-01

    This report represents the tenth Semi-Annual Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government-Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the Green Pond Mine site at the Township Compost Storage Facility, engineering continued during this reporting period toward development of the Construction Plans and Technical Specifications for the remediation work. At the Mt. Hope Road subsidence, surface monitoring was conducted periodically at the work area and adjacent areas after the January 2000 construction effort.

  1. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TOWNSHIP, NEW JERSEY

    Energy Technology Data Exchange (ETDEWEB)

    Gary Gartenberg

    2003-12-01

    This report represents the thirteenth Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this semi annual reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government--Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the Green Pond Mine site at the Township's Jacobs Road Compost Storage Facility, construction was completed during this reporting period and surface monitoring began. Surface monitoring was conducted periodically at the Mt. Hope Road subsidence work area and adjacent areas after the January 2000 construction effort.

  2. Closure plan for Corrective Action Unit 109: U-2bu subsidence crater, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The U-2bu subsidence crater, Corrective Action Unit 109, will be closed in accordance with the Resource Conservation and Recovery Act, the Nevada Division of Environmental Protection operational permit, and the Federal Facility Agreement and Consent Order. The U-2bu subsidence crater is located in Area 2 of the Nevada Test Site. It was created in 1971 by an underground nuclear test with the name Miniata. The crater has a diameter of 288 meters (944 feet) and an approximate depth of 35 meters (115 feet). Based on the results of the analyses reported in the site characterization report, the only constituents of concern in the U-2bu subsidence crater include leachable lead and total petroleum hydrocarbons. Closure activities will include the excavation and disposal of impacted soil from the top of the crater. Upon completion of excavation, verification samples will be collected to show that the leachable lead has been removed to concentrations below the regulatory action level. After sample results show that the lead has been removed, the excavated area will be backfilled and a soil flood diversion berm will be constructed as a best management practice. An independent registered professional engineer will certify the site was closed following the approved Closure Plan. Post-closure care is not warranted for this site because closure activities will involve removal of the Resource Conservation and Recovery Act constituents of concern.

  3. Closure Plan for Corrective Action Unit 109: U-2bu Subsidence Crater Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Shannon Parsons

    1999-03-01

    The U-2bu subsidence crater, Corrective Action Unit 109, will be closed in accordance with the Resource Conservation and Recovery Act, the Nevada Division of Environmental Protection operational permit, and the Federal Facilities Agreement and Consent Order. The U-2bu subsidence crater is located in Area 2 of the Nevada Test Site. It was created in 1971 by an underground nuclear test with the name Miniata. The crater has a diameter of 288 meters (944 feet) and an approximate depth of 35 meters (115 feet). The subsidence crater was used as a land disposal unit for radioactive and hazardous waste from 1973 to 1988. Site disposal history is supported by memorandums, letters, and personnel who worked at the Nevada Test Site at the time of active disposal. Closure activities will include the excavation and disposal of impacted soil form the tip of the crater. Upon completion of excavation, verification samples will be collected to show that lead has been removed to concentrations be low regulatory action level. The area will then be backfilled and a soil flood diversion berm will be constructed, and certified by an independent professional engineer as to having followed the approved Closure Plan.

  4. Land subsidence of clay deposits after the Tohoku-Pacific Ocean Earthquake

    Directory of Open Access Journals (Sweden)

    K. Yasuhara

    2015-11-01

    Full Text Available Extensive infrastructure collapse resulted from the cataclysmic earthquake that struck off the eastern coast of Japan on 11 March 2011 and from its consequent gigantic tsunami, affecting not only the Tohoku region but also the Kanto region. Among the geological and geotechnical processes observed, land subsidence occurring in both coastal and inland areas and from Tohoku to Kanto is an extremely important issue that must be examined carefully. This land subsidence is classifiable into three categories: (i land sinking along the coastal areas because of tectonic movements, (ii settlement of sandy deposits followed by liquefaction, and (iii long-term post-earthquake recompression settlement in soft clay caused by dissipation of excess pore pressure. This paper describes two case histories of post-earthquake settlement of clay deposits from among the three categories of ground sinking and land subsidence because such settlement has been frequently overlooked in numerous earlier earthquakes. Particularly, an attempt is made to propose a methodology for predicting such settlement and for formulating remedial or responsive measures to mitigate damage from such settlement.

  5. Land subsidence of clay deposits after the Tohoku-Pacific Ocean Earthquake

    Science.gov (United States)

    Yasuhara, K.; Kazama, M.

    2015-11-01

    Extensive infrastructure collapse resulted from the cataclysmic earthquake that struck off the eastern coast of Japan on 11 March 2011 and from its consequent gigantic tsunami, affecting not only the Tohoku region but also the Kanto region. Among the geological and geotechnical processes observed, land subsidence occurring in both coastal and inland areas and from Tohoku to Kanto is an extremely important issue that must be examined carefully. This land subsidence is classifiable into three categories: (i) land sinking along the coastal areas because of tectonic movements, (ii) settlement of sandy deposits followed by liquefaction, and (iii) long-term post-earthquake recompression settlement in soft clay caused by dissipation of excess pore pressure. This paper describes two case histories of post-earthquake settlement of clay deposits from among the three categories of ground sinking and land subsidence because such settlement has been frequently overlooked in numerous earlier earthquakes. Particularly, an attempt is made to propose a methodology for predicting such settlement and for formulating remedial or responsive measures to mitigate damage from such settlement.

  6. Peatland subsidence: are the biggest problems to be expected in the tropics?

    Science.gov (United States)

    Hooijer, A.; Erkens, G.; Vernimmen, R.; Page, S.; Triadi, B.; Applegate, G.

    2012-12-01

    Subsidence in drained peatlands is mainly caused by oxidation, which is highly temperature dependent. Subsidence rates, and the associated carbon emissions, are therefore far higher in tropical regions than in the temperate areas where most research has been done to date. In SE Asia alone, up to 25 Mha of lowland peatland is now being drained in ways that are unlikely to be sustainable beyond the short term, as surface lowering by about 4 metres within 50 years is expected to cause large-scale inundation and loss of agricultural production. Problems of similar scale may become apparent in other tropical regions, as agriculture expands into ever less suitable areas including peatlands. Applying recent findings on peat thickness, surface elevation and subsidence rate, we can now demonstrate the scale and timing of such problems for case study areas in Indonesia. To allow reduction of such impacts, which may be mitigated but often not prevented, it is important that local conditions are not seen in isolation, but rather investigated from a global perspective that integrates findings from different climate regions. Data from the Everglades and Sacramento Delta, peatlands in warm climates that were drained 100 years ago, provide the best analogue to what can be expected at a far larger scale in tropical regions.

  7. Southern Perú coseismic subsidence: 23 June 2001 8.4-Mw earthquake

    Science.gov (United States)

    Ocola, L.

    2008-01-01

    The 23-June-2001 8.4-Mw magnitude earthquake partially filled the 1868-seismic-gap in southern Perú. This earthquake produced a thrust faulting dislocation with a rupture that started at about ~200 km SE from the 1996's Nazca earthquake epicenter, and stopped near Ilo, at about 300 km from the epicenter, near a positive gravity anomaly offshore Ilo. The 23-June-2001-earthquake dislocation zone is under the Arequipa sedimentary Basin. Pre- and post-seismic GPS measurements at Camaná and Ilo at SIRGAS-GPS points (SIRGAS: Sistema de Referencia Geocéntrico para América del Sur) and the average sea level pre- and post-seismic event at Mollendo tide gauge provide evidence of a regional subsidence of southern Perú, with 84 cm at Camaná, 16 cm at Ilo, and 15 cm at Mollendo. Field surveys post earthquake document significant subsidence in Camaná resort beaches. Results of a simple dislocation modelling of 23-June-2001 earthquake agree reasonably well with the observed data. However, the coseismic subsidence of southern Perú is at variance with the regional uplift of southern Perú based on Neotectonic studies. This fact, suggests that, in recent geological times, the magnitude of the secular uplift due to tectonic plate converge has been larger than the coseismic deformation recovery.

  8. Inundation, sedimentation, and subsidence creates goose habitat along the Arctic coast of Alaska

    Science.gov (United States)

    Tape, Ken D.; Flint, Paul L.; Meixell, Brandt W.; Gaglioti, Benjamin V.

    2013-01-01

    The Arctic Coastal Plain of Alaska is characterized by thermokarst lakes and drained lake basins, and the rate of coastal erosion has increased during the last half-century. Portions of the coast are permafrost. Increased storm surges or terrestrial subsidence would therefore expand the area subject to marine inundation. Since 1976, the distribution of molting Black Brant (Branta bernicla nigricans) on the Arctic Coastal Plain has shifted from inland freshwater lakes to coastal marshes, such as those occupying the Smith River and Garry Creek estuaries. We hypothesized that the movement of geese from inland lakes was caused by an expansion of high quality goose forage in coastal areas. We examined the recent history of vegetation and geomorphological changes in coastal goose habitat by combining analysis of time series imagery between 1948 and 2010 with soil stratigraphy dated using bomb-curve radiocarbon. Time series of vertical imagery and in situ verification showed permafrost thaw and subsidence of polygonal tundra. Soil stratigraphy and dating within coastal estuaries showed that non-saline vegetation communities were buried by multiple sedimentation episodes between 1948 and 1995, accompanying a shift toward salt-tolerant vegetation. This sedimentation allowed high quality goose forage plants to expand, thus facilitating the shift in goose distribution. Declining sea ice and the increasing rate of terrestrial inundation, sedimentation, and subsidence in coastal estuaries of Alaska may portend a 'tipping point' whereby inland areas would be transformed into salt marshes.

  9. Non-Linear Land Subsidence In Morelia, Mexico, Imaged Through Synthetic Aperture Radar Interferometry

    Science.gov (United States)

    Cigna, Francesca; Osmanoglu, Batuhan; Cabral-Cano, Enrique; Dixon, Timothy H.; Wdowinski, Shimon

    2012-01-01

    Land subsidence affecting the city of Morelia in 2003- 2010 is imaged with 23 ENVISAT scenes. Newly developed subsidence is recognized in the Rio Grande meander area, where thick compressible deposits suffer from accelerated aquifer compaction induced by recent groundwater extractions. Persistent Scatterer (PS) analyses using linear and quadratic deformation models both result in low density of targets, while small- baseline interferograms show good coherence over the whole area. At the location of Prados Verdes II well, located in the center of this subsidence feature, -10 to -15 mm/yr LOS velocities are measured in 2003-2004, accelerating to -30 mm/yr in 2004-2005, -40 to -50 mm/yr in 2006-2007, and -60 to -70 mm/yr in 2008- 2009. Along the vertical direction, cumulative deformation in 2003-2009 at the water well location is estimated at -280 mm. Accelerations as high as -1 to -1.5 mm/yr2 are observed by PS for the time period 2003-2010.

  10. Production induced subsidence and seismicity in the Groningen gas field - can it be managed?

    Science.gov (United States)

    de Waal, J. A.; Muntendam-Bos, A. G.; Roest, J. P. A.

    2015-11-01

    Reliable prediction of the induced subsidence resulting from gas production is important for a near sea level country like the Netherlands. Without the protection of dunes, dikes and pumping, large parts of the country would be flooded. The predicted sea-level rise from global warming increases the challenge to design proper mitigation measures. Water management problems from gas production induced subsidence can be prevented if measures to counter its adverse effects are taken timely. This requires reliable subsidence predictions, which is a major challenge. Since the 1960's a number of large, multi-decade gas production projects were started in the Netherlands. Extensive, well-documented subsidence prediction and monitoring technologies were applied. Nevertheless predicted subsidence at the end of the Groningen field production period (for the centre of the bowl) went from 100 cm in 1971 to 77 cm in 1973 and then to 30 cm in 1977. In 1984 the prediction went up again to 65 cm, down to 36 cm in 1990 and then via 38 cm (1995) and 42 cm (2005) to 47 cm in 2010 and 49 cm in 2013. Such changes can have large implications for the planning of water management measures. Until 1991, when the first event was registered, production induced seismicity was not observed nor expected for the Groningen field. Thereafter the number of observed events rose from 5 to 10 per year during the 1990's to well over a hundred in 2013. The anticipated maximum likely magnitude rose from an initial value of less than 3.0 to a value of 3.3 in 1993 and then to 3.9 in 2006. The strongest tremor to date occurred near the village of Huizinge in August 2012. It had a magnitude of 3.6, caused significant damage and triggered the regulator into an independent investigation. Late 2012 it became clear that significantly larger magnitudes cannot be excluded and that values up to magnitude 5.0 cannot be ruled out. As a consequence the regulator advised early 2013 to lower Groningen gas production by as

  11. Southern Perú coseismic subsidence: 23 June 2001 8.4-Mw earthquake

    Directory of Open Access Journals (Sweden)

    L. Ocola

    2008-01-01

    Full Text Available The 23-June-2001 8.4-Mw magnitude earthquake partially filled the 1868-seismic-gap in southern Perú. This earthquake produced a thrust faulting dislocation with a rupture that started at about ~200 km SE from the 1996's Nazca earthquake epicenter, and stopped near Ilo, at about 300 km from the epicenter, near a positive gravity anomaly offshore Ilo. The 23-June-2001-earthquake dislocation zone is under the Arequipa sedimentary Basin. Pre- and post-seismic GPS measurements at Camaná and Ilo at SIRGAS-GPS points (SIRGAS: Sistema de Referencia Geocéntrico para América del Sur and the average sea level pre- and post-seismic event at Mollendo tide gauge provide evidence of a regional subsidence of southern Perú, with 84 cm at Camaná, 16 cm at Ilo, and 15 cm at Mollendo. Field surveys post earthquake document significant subsidence in Camaná resort beaches. Results of a simple dislocation modelling of 23-June-2001 earthquake agree reasonably well with the observed data. However, the coseismic subsidence of southern Perú is at variance with the regional uplift of southern Perú based on Neotectonic studies. This fact, suggests that, in recent geological times, the magnitude of the secular uplift due to tectonic plate converge has been larger than the coseismic deformation recovery.

  12. Long-term subsidence, cooling, and exhumation history along the South Atlantic passive continental margin in NW-Namibia

    Science.gov (United States)

    Menges, Daniel; Glasmacher, Ulrich Anton; Salomon, Eric; Hackspacher, Peter Christian; Schneider, Gabi

    2017-04-01

    In northwestern Namibia the Kaoko Belt is one of the most important Precambrian crustal segments that have stored the subsidence, cooling, and exhumation history of Namibia since the Neoproterozoic. ZFT-ages, with ages between 292.7 (46.0) and 436.8 (45.9) Ma, are giving new insights on this early evolution. Paleozoic to Mesozoic sedimentary rocks of the Karoo Supergroup and the Lower Cretaceous volcanic rocks of the Etendeka sequence overlay the Proterozoic metamorphic and intrusive rocks (1). New apatite fission-track (AFT) ages range from 390.9 (17.9) Ma to 80.8 (6.0) Ma. Along the coast apatites of Proterozoic rock samples reveal the youngest ages. Further inland the ages increase significantly. In addition, rapid change of AFT-ages occurs on both sides of major thrust and shear zones. Using the oldest thermochronological data the revealed t-T paths indicate a long era of exhumation, starting at the end of the Pan-African Orogeny in the Neoproterozoic and continuing into the Permo-Carboniferous. The subsequent sedimentation of the Karoo Supergroup initiates a new era of subsidence until the end of Triassic (2).The subsequent period of denudation ends abruptly with the rapid deposition of the Etendeka basalts in the Early Cretaceous (3). The maximum thickness of the Etendeka volcanic suite has been estimated, using the apatite fission-track data, to about 3.2 (1.2) km. With the ongoing opening of the South Atlantic and the formation of the continental margin the Kaoko Belt went through a rapid cooling event starting 130 Ma and ending 80 Ma, at a mean rate of 0.034 km/Ma for the western, and 0.018 km/Ma for the northern and eastern Kaoko Belt. This cooling event was accompanied by a reactivation of major fault zones, like the Purros Mylonite Zone (4). Thereafter, stable conditions were established, with denudation rates generally lower than 0.010 km/Ma, until the Neogene, where a second cooling event led to increased exhumation rates around 0.042 km/Ma. The total

  13. Increasing Access to Subsidized Artemisinin-based Combination Therapy through Accredited Drug Dispensing Outlets in Tanzania

    Directory of Open Access Journals (Sweden)

    Gabra Michael

    2011-06-01

    Full Text Available Abstract Background In Tanzania, many people seek malaria treatment from retail drug sellers. The National Malaria Control Program identified the accredited drug dispensing outlet (ADDO program as a private sector mechanism to supplement the distribution of subsidized artemisinin-based combination therapies (ACTs from public facilities and increase access to the first-line antimalarial in rural and underserved areas. The ADDO program strengthens private sector pharmaceutical services by improving regulatory and supervisory support, dispenser training, and record keeping practices. Methods The government's pilot program made subsidized ACTs available through ADDOs in 10 districts in the Morogoro and Ruvuma regions, covering about 2.9 million people. The program established a supply of subsidized ACTs, created a price system with a cost recovery plan, developed a plan to distribute the subsidized products to the ADDOs, trained dispensers, and strengthened the adverse drug reactions reporting system. As part of the evaluation, 448 ADDO dispensers brought their records to central locations for analysis, representing nearly 70% of ADDOs operating in the two regions. ADDO drug register data were available from July 2007-June 2008 for Morogoro and from July 2007-September 2008 for Ruvuma. This intervention was implemented from 2007-2008. Results During the pilot, over 300,000 people received treatment for malaria at the 448 ADDOs. The percentage of ADDOs that dispensed at least one course of ACT rose from 26.2% during July-September 2007 to 72.6% during April-June 2008. The number of malaria patients treated with ACTs gradually increased after the start of the pilot, while the use of non-ACT antimalarials declined; ACTs went from 3% of all antimalarials sold in July 2007 to 26% in June 2008. District-specific data showed substantial variation among the districts in ACT uptake through ADDOs, ranging from ACTs representing 10% of all antimalarial sales

  14. Differential subsidence and its effect on subsurface infrastructure: predicting probability of pipeline failure (STOOP project)

    Science.gov (United States)

    de Bruijn, Renée; Dabekaussen, Willem; Hijma, Marc; Wiersma, Ane; Abspoel-Bukman, Linda; Boeije, Remco; Courage, Wim; van der Geest, Johan; Hamburg, Marc; Harmsma, Edwin; Helmholt, Kristian; van den Heuvel, Frank; Kruse, Henk; Langius, Erik; Lazovik, Elena

    2017-04-01

    Due to heterogeneity of the subsurface in the delta environment of the Netherlands, differential subsidence over short distances results in tension and subsequent wear of subsurface infrastructure, such as water and gas pipelines. Due to uncertainties in the build-up of the subsurface, however, it is unknown where this problem is the most prominent. This is a problem for asset managers deciding when a pipeline needs replacement: damaged pipelines endanger security of supply and pose a significant threat to safety, yet premature replacement raises needless expenses. In both cases, costs - financial or other - are high. Therefore, an interdisciplinary research team of geotechnicians, geologists and Big Data engineers from research institutes TNO, Deltares and SkyGeo developed a stochastic model to predict differential subsidence and the probability of consequent pipeline failure on a (sub-)street level. In this project pipeline data from company databases is combined with a stochastic geological model and information on (historical) groundwater levels and overburden material. Probability of pipeline failure is modelled by a coupling with a subsidence model and two separate models on pipeline behaviour under stress, using a probabilistic approach. The total length of pipelines (approx. 200.000 km operational in the Netherlands) and the complexity of the model chain that is needed to calculate a chance of failure, results in large computational challenges, as it requires massive evaluation of possible scenarios to reach the required level of confidence. To cope with this, a scalable computational infrastructure has been developed, composing a model workflow in which components have a heterogeneous technological basis. Three pilot areas covering an urban, a rural and a mixed environment, characterised by different groundwater-management strategies and different overburden histories, are used to evaluate the differences in subsidence and uncertainties that come with

  15. Land subsidence in the Yangtze River Delta, China revealed from multi-frequency SAR Interferometry

    Science.gov (United States)

    Li, Zhenhong; Motagh, Mahdi; Yu, Jun; Gong, Xulong; Wu, Jianqiang; Zhu, Yefei; Chen, Huogen; Zhang, Dengming; Xu, Yulin

    2014-05-01

    Land subsidence is a major worldwide hazard, and its principal causes are subsurface fluid withdrawal, drainage of organic soils, sinkholes, underground mining, hydrocompaction, thawing permafrost, and natural consolidation. Land subsidence causes many problems including: damage to public facilities such as bridges, roads, railroads, electric power lines, underground pipes; damage to private and public buildings; and in some cases of low-lying land, can increase the risk of coastal flooding from storm surges and rising sea-levels. In China, approximately 48600 km2 of land, an area roughly 30 times of the size of the Greater London, has subsided (nearly 50 cities across 16 provinces), and the annual direct economic loss is estimated to be more than RMB 100 million (~12 million). It is believed that the Suzhou-Wuxi-Changzhou region within the Yangtze River Delta is the most severely affected area for subsidence hazards in China. With its global coverage and all-weather imaging capability, Interferometric SAR (InSAR) is revolutionizing our ability to image the Earth's surface and the evolution of its shape over time. In this paper, an advanced InSAR time series technique, InSAR TS + AEM, has been employed to analysed ERS (C-band), Envisat (C-band) and TerraSAR-X (X-band) data collected over the Suzhou-Wuxi-Changzhou region during the period from 1992 to 2013. Validation with precise levelling and GPS data suggest: (1) the accuracy of the InSAR-derived mean velocity measurements is 1-3 mm/yr; (2) InSAR-derived displacements agreed with precise levelling with root mean square errors around 5 mm. It is evident that InSAR TS + AEM can be used to image the evolution of deformation patterns in the Suzhou-Wuxi-Changzhou region over time: the maximum mean velocity decreased from ~12 cm/yr during the period of 1992-1993 to ~2 cm/yr in 2003-2013. This is believed to be a result of the prohibition of groundwater use carried out by Jiangsu provincial government. The combination

  16. Subsidence Induced Faulting Hazard Zonation Using Persistent Scatterer Interferometry and Horizontal Gradient Mapping in Mexican Urban Areas

    Science.gov (United States)

    Cabral-Cano, E.; Cigna, F.; Osmanoglu, B.; Dixon, T.; Wdowinski, S.

    2011-12-01

    Subsidence and faulting have affected Mexico city for more than a century and the process is becoming widespread throughout larger urban areas in central Mexico. This process causes substantial damages to the urban infrastructure and housing structures and will certainly become a major factor to be considered when planning urban development, land use zoning and hazard mitigation strategies in the next decades. Subsidence is usually associated with aggressive groundwater extraction rates and a general decrease of aquifer static level that promotes soil consolidation, deformation and ultimately, surface faulting. However, local stratigraphic and structural conditions also play an important role in the development and extension of faults. In all studied cases stratigraphy of the uppermost sediment strata and the structure of the underlying volcanic rocks impose a much different subsidence pattern which is most suitable for imaging through satellite geodetic techniques. We present examples from several cities in central Mexico: a) Mexico-Chalco. Very high rates of subsidence, up to 370 mm/yr are observed within this lacustrine environment surrounded by Pliocene-Quaternary volcanic structures. b) Aguascalientes where rates up to 90 mm/yr in the past decade are observed, is controlled by a stair stepped N-S trending graben that induces nucleation of faults along the edges of contrasting sediment package thicknesses. c) Morelia presents subsidence rates as high as 80 mm/yr. Differential deformation is observed across major basin-bounding E-W trending faults and with higher subsidence rates on their hanging walls, where the thickest sequences of compressible Quaternary sediments crop out. Our subsidence and faulting study in urban areas of central Mexico is based on a horizontal gradient analysis using displacement maps from Persistent Scatterer InSAR that allows definition of areas with high vulnerability to surface faulting. Correlation of the surface subsidence pattern

  17. E-Area Low-Level Waste Facility Vadose Zone Model: Confirmation of Water Mass Balance for Subsidence Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, J. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-11-30

    In preparation for the next revision of the E-Area Low-Level Waste Facility (LLWF) Performance Assessment (PA), a mass balance model was developed in Microsoft Excel to confirm correct implementation of intact- and subsided-area infiltration profiles for the proposed closure cap in the PORFLOW vadose-zone model. The infiltration profiles are based on the results of Hydrologic Evaluation of Landfill Performance (HELP) model simulations for both intact and subsided cases.

  18. Quantification of groundwater extraction-induced subsidence in the Mekong delta, Vietnam: 3D process-based numerical modeling

    Science.gov (United States)

    Minderhoud, Philip S. J.; Erkens, Gilles; Pham, Hung V.; Bui, Vuong T.; Kooi, Henk; Erban, Laura; Stouthamer, Esther

    2017-04-01

    The demand for groundwater in the Vietnamese Mekong delta has steadily risen over the past decades. As a result, hydraulic heads in the aquifers dropped on average 0.3-0.7 m/yr-1, potentially causing aquifer-system compaction. At present, the delta is experiencing subsidence rates up to several centimeters per year that outpace global sea level rise by an order of magnitude. However, the exact contribution of groundwater extraction to total subsidence in the delta has not been assessed yet. The objective of our study is to quantify the impact of 25 years of groundwater extraction on subsidence. We built a 3D numerical hydrogeological model comprising the multi-aquifer system of the entire Vietnamese Mekong delta. Groundwater dynamics in the aquifers was simulated over the past quarter-century based on the known extraction history and measured time series of hydraulic head. Subsequently, we calculated corresponding aquifer system compaction using a coupled land subsidence module, which includes a direct, elastic component and a secular, viscous component (i.e. creep). The hydrogeological model is able to reproduce the measured drawdowns in the multi-aquifer system of the past 25 years. Corresponding subsidence rates resulting from aquifer system compaction show a gradual increase over the past two decades to significant annual rates up to several centimeters. Groundwater extraction seems to be a dominant driver of subsidence in the delta, but does not explain the total measured subsidence. This process-based modeling approach can be used to quantify groundwater extraction-induced subsidence for coastal areas and at delta-scale worldwide.

  19. Effects of groundwater regulation on aquifer-system compaction and subsidence in the Houston-Galveston Region, Texas, USA

    Science.gov (United States)

    Turco, M. J.; Petrov, A.

    2015-11-01

    Subsidence has been a primary concern in the Houston area for many years. Since 1906, about 4 m of subsidence has occurred in the coastal areas, with a broad area of about 2 m of subsidence existing today throughout most of the Houston Area. In 1975, as a result of area residents and local governments becoming increasingly alarmed by the continued impact of subsidence on economic growth and quality of life in the region, the Harris-Galveston Subsidence District was created by the 64th Texas Legislature as an underground water conservation district with the mission to provide for the regulation of the withdrawal of groundwater to control subsidence. Over its nearly 40 years of existence, the District has developed substantial data sets providing the foundation for its regulatory plan. The District's regulatory plan allows groundwater users an amount of annual groundwater based on a percentage of an individual permitee's total water demand. The management of the groundwater resources within the District has involved significant coordination with regional ground and surface water suppliers; ongoing interaction with other state and local regulatory bodies; analysis of accurate and up to date predictions on water usage; the enforcement of disincentives to those who rely too heavily on groundwater and a commitment to practicing and promoting water conservation. Areas nearest the Gulf of Mexico coast have completed the conversion to alternative (other than groundwater) water sources, consequently the effective stress on the aquifer has decreased and subsidence rates have been reduced. Areas within the District further inland are currently proceeding through the conversion process, and subsidence has continued in those areas as development of the groundwater resources has continued.

  20. Effects of groundwater regulation on aquifer-system compaction and subsidence in the Houston-Galveston Region, Texas, USA

    Directory of Open Access Journals (Sweden)

    M. J. Turco

    2015-11-01

    Full Text Available Subsidence has been a primary concern in the Houston area for many years. Since 1906, about 4 m of subsidence has occurred in the coastal areas, with a broad area of about 2 m of subsidence existing today throughout most of the Houston Area. In 1975, as a result of area residents and local governments becoming increasingly alarmed by the continued impact of subsidence on economic growth and quality of life in the region, the Harris-Galveston Subsidence District was created by the 64th Texas Legislature as an underground water conservation district with the mission to provide for the regulation of the withdrawal of groundwater to control subsidence. Over its nearly 40 years of existence, the District has developed substantial data sets providing the foundation for its regulatory plan. The District's regulatory plan allows groundwater users an amount of annual groundwater based on a percentage of an individual permitee's total water demand. The management of the groundwater resources within the District has involved significant coordination with regional ground and surface water suppliers; ongoing interaction with other state and local regulatory bodies; analysis of accurate and up to date predictions on water usage; the enforcement of disincentives to those who rely too heavily on groundwater and a commitment to practicing and promoting water conservation. Areas nearest the Gulf of Mexico coast have completed the conversion to alternative (other than groundwater water sources, consequently the effective stress on the aquifer has decreased and subsidence rates have been reduced. Areas within the District further inland are currently proceeding through the conversion process, and subsidence has continued in those areas as development of the groundwater resources has continued.

  1. Deep Structure and Subsidence History of Parnaíba Cratonic Basin, NE Brazil

    Science.gov (United States)

    Rodríguez Tribaldos, Verónica; White, Nicky; Coelho, Diogo; Julià, Jordi

    2017-04-01

    Cratonic sedimentary basins constitute some of the largest sedimentary basins on Earth. They are typically underlain by thick (i.e. 200 km) lithosphere and are characterized by slow, punctuated subsidence that occurs over hundreds of millions of years. Their stratigraphic records mainly consist of sequences of continental and shallow marine sedimentary rocks bounded by basin-wide erosional unconformities. Despite the importance of these basins, their origin and evolution remain poorly understood, mainly due to scarcity of well-constrained geological and geophysical data. In order to address this problem, an integrative study of the Parnaíba Cratonic basin in NE Brazil has been carried out within the framework of a multidisciplinary investigation. Here, we combine the analysis of a 1400 km long deep seismic reflection profile that crosses the basin, teleseismic earthquakes recorded by 12 broadband and 10 short-period, 3 component seismometers, 25 ancillary seismic reflection profiles, and 46 wells distributed across the basin. Our main goal is to constrain the basin's subsidence history in the context of its deep crustal structure and sedimentary architecture. Joint inversion of receiver functions and Rayleigh wave group dispersion measurements has been used to calculate 1D shear wave velocity models for crust and upper mantle beneath each seismic station. Combined interpretation of these velocity profiles and the deep seismic reflection profile has been carried out. Our results suggest Moho depths of approximately 35 km and 38 km beneath Precambrian basement east and west of the Parnaíba basin, respectively. In contrast, the Moho occurs at approximately 39 km beneath the city of Teresina, located on the eastern region of the basin, and at depths between 40 km and 42 km beneath the central and western areas of the basin. These results are combined to construct a sub-surface model underneath Parnaíba, and gravity modeling is used to test its validity. Average

  2. Investigating ground deformation and subsidence in northern Metro Manila, Philippines using Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR)

    Science.gov (United States)

    Eco, R. C.; Lagmay, A. A.; Bato, M. P.

    2011-12-01

    The extent of ground deformation and subsidence in northern Metro Manila was examined using Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique. Using the Stanford Method for Persistent Scatterers/Multi-Temporal InSAR (StaMPS/MTI) software, we processed 21 descending ENVISAT radar imageries taken from 2003 to 2006. The processed interferograms show high coherence due to the high density of PS points in the region of interest. The PSInSAR processing reveals several areas in northern Metro Manila, specifically in Caloocan, Malabon, Navotas and Valenzuela-collectively known as CAMANAVA-that exhibit deformation characteristics similar to that of ground subsidence. Results show that the areas manifesting apparent subsidence are moving with a maximum rate of 4.38 cm/year relative to the satellite. This is consistent with the geodetic surveying results from 1979 to 2009 showing subsidence of approximately 1 meter or 3.33 cm/year per year. Government data also identify these areas as among those with the highest rates of groundwater extraction in Metro Manila, suggesting the possibility of anthropogenic activities as the major cause of subsidence. With this study, we hope to get a better understanding of the nature of subsidence affecting parts of northern Metro Manila. Doing so would help mitigate the effects of potential flood disasters.

  3. Using temporarily coherent point interferometric synthetic aperture radar for land subsidence monitoring in a mining region of western China

    Science.gov (United States)

    Fan, Hongdong; Xu, Qiang; Hu, Zhongbo; Du, Sen

    2017-04-01

    Yuyang mine is located in the semiarid western region of China where, due to serious land subsidence caused by underground coal exploitation, the local ecological environment has become more fragile. An advanced interferometric synthetic aperture radar (InSAR) technique, temporarily coherent point InSAR, is applied to measure surface movements caused by different mining conditions. Fifteen high-resolution TerraSAR-X images acquired between October 2, 2012, and March 27, 2013, were processed to generate time-series data for ground deformation. The results show that the maximum accumulated values of subsidence and velocity were 86 mm and 162 mm/year, respectively; these measurements were taken above the fully mechanized longwall caving faces. Based on the dynamic land subsidence caused by the exploitation of one working face, the land subsidence range was deduced to have increased 38 m in the mining direction with 11 days' coal extraction. Although some mining faces were ceased in 2009, they could also have contributed to a small residual deformation of overlying strata. Surface subsidence of the backfill mining region was quite small, the maximum only 21 mm, so backfill exploitation is an effective method for reducing the land subsidence while coal is mined.

  4. Subsidizing Liquidity

    DEFF Research Database (Denmark)

    Malinova, Katya; Park, Andreas

    2015-01-01

    Facing increased competition over the last decade, many stock exchanges changed their trading fees to maker-taker pricing, an incentive scheme that rewards liquidity suppliers and charges liquidity demanders. Using a change in trading fees on the Toronto Stock Exchange, we study whether and why...... the breakdown of trading fees between liquidity demanders and suppliers matters. Posted quotes adjust after the change in fee composition, but the transaction costs for liquidity demanders remain unaffected once fees are taken into account. However, as posted bid-ask spreads decline, traders (particularly...... retail) use aggressive orders more frequently, and adverse selection costs decrease....

  5. Subsidence monitoring network: an Italian example aimed at a sustainable hydrocarbon E&P activity

    Science.gov (United States)

    Dacome, M. C.; Miandro, R.; Vettorel, M.; Roncari, G.

    2015-11-01

    According to the Italian law in order to start-up any new hydrocarbon exploitation activity, an Environmental Impact Assessment study has to be presented, including a monitoring plan, addressed to foresee, measure and analyze in real time any possible impact of the project on the coastal areas and on those ones in the close inland located. The occurrence of subsidence, that could partly be related to hydrocarbon production, both on-shore and off-shore, can generate great concern in those areas where its occurrence may have impacts on the local environment. ENI, following the international scientific community recommendations on the matter, since the beginning of 90's years, implemented a cutting-edge monitoring network, with the aim to prevent, mitigate and control geodynamics phenomena generated in the activity areas, with a particular attention to conservation and protection of environmental and territorial equilibrium, taking care of what is known as "sustainable development". The current ENI implemented monitoring surveys can be divided as: - Shallow monitoring: spirit levelling surveys, continuous GPS surveys in permanent stations, SAR surveys, assestimeter subsurface compaction monitoring, ground water level monitoring, LiDAR surveys, bathymetrical surveys. - Deep monitoring: reservoir deep compaction trough radioactive markers, reservoir static (bottom hole) pressure monitoring. All the information, gathered through the monitoring network, allow: 1. to verify if the produced subsidence is evolving accordingly with the simulated forecast. 2. to provide data to revise and adjust the prediction compaction models 3. to put in place the remedial actions if the impact exceeds the threshold magnitude originally agreed among the involved parties. ENI monitoring plan to measure and monitor the subsidence process, during field production and also after the field closure, is therefore intended to support a sustainable field development and an acceptable exploitation

  6. Spectacle dispensing in Timor-Leste: tiered-pricing, cross-subsidization and financial viability.

    Science.gov (United States)

    Ramke, Jacqueline; Brian, Garry; Palagyi, Anna

    2012-08-01

    To examine the financial viability of the Timor-Leste National Spectacle Program as it increases spectacle availability, affordability and uptake, particularly for Timor's poor. In rural areas, three models of ready-made spectacles were dispensed according to a tiered pricing structure of US$3.00, 1.00, 0.10 and 0.00. In addition, custom-made spectacles were available in the capital, Dili. Spectacle costs, dispensing data and income for the National Spectacle Program for 18 months from March 2007 were analyzed. Rural services dispensed 3415 readymade spectacles: 47.1% to women, and 51.4% at subsidized prices, being 39.8% at US$0.10 and 11.6% free. A profit of US$1,529 was generated, mainly from the sale of US$3.00 spectacles. Women (odds ratio, OR, 1.3, 95% confidence interval, CI, 1.1-1.4) and consumers aged ≥65 years (OR 2.1; 95% CI 1.7-2.6) were more likely to receive subsidized spectacles. Urban services dispensed 2768 spectacles; mostly US$3.00 readymade (52.8%) and custom-made single vision (29.6%) units. Custom-made spectacles accounted for 36.7% of dispensing, but 73.1% of the US$12,264 urban profit. The combined rural and urban profit covered all rural costs, leaving US$2,200 to meet administration and other urban expenses. It is instructive and encouraging that a national spectacle dispensing program in one of the ten poorest countries of the world can use tiered-pricing based on willingness-to-pay information to cover spectacle stock replacement costs and produce profit, while using cross-subsidization to provide spectacles to the poor.

  7. Constraints on dynamic topography from asymmetric subsidence of the mid-ocean ridges

    Science.gov (United States)

    Watkins, C. Evan; Conrad, Clinton P.

    2018-02-01

    Stresses from mantle convection deflect Earth's surface vertically, producing dynamic topography that is important for continental dynamics and sea-level change but difficult to observe due to overprinting by isostatic topography. For long wavelengths (∼104 km), the amplitude of dynamic topography is particularly uncertain, with mantle flow models typically suggesting larger amplitudes (>1000 m) than direct observations. Here we develop a new constraint on the amplitude of long-wavelength dynamic topography by examining asymmetries in seafloor bathymetry across mid-ocean ridges. We compare bathymetric profiles across the Mid-Atlantic Ridge (MAR) and the East Pacific Rise (EPR) and we find that the South American flank of both ridges subsides faster than its opposing flank. This pattern is consistent with dynamic subsidence across South America, supported by downwelling in the lower mantle. To constrain the amplitude of dynamic topography, we compare bathymetric profiles across both ridges after correcting bathymetry for several different models of dynamic topography with varying amplitudes and spatial patterns. We find that long-wavelength dynamic topography with an amplitude of only ∼500 m explains the observed asymmetry of the MAR. A similar model can explain EPR asymmetry but is complicated by additional asymmetrical topography associated with tectonic, crustal thickness, and/or asthenospheric temperature asymmetries across the EPR. After removing 500 m of dynamic topography, both the MAR and EPR exhibit a slower seafloor subsidence rate (∼280-290 m/Myr1/2) than previously reported. Our finding of only ∼500 m of long-wavelength dynamic topography may indicate the importance of thermochemical convection and/or large viscosity variations for lower mantle dynamics.

  8. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TOWNSHIP, NEW JERSEY

    Energy Technology Data Exchange (ETDEWEB)

    Gary Gartenberg, P.E., P.P.

    2001-04-01

    This report represents the seventh Semi-Annual Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government--Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the Green Pond Mine site at the Township Compost Storage Facility, research and preliminary design was performed during this reporting period toward development of the engineering plans and Technical Specifications for the remediation work. At the White Meadow Mine site, the remediation project was conducted last reporting period by others, out of the responsibility of Rockaway Township under this Cooperators Agreement. At the Mt. Hope Road subsidence, surface monitoring was conducted at the work area and adjacent areas after the January 2000 construction effort.

  9. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TOWNSHIP, NEW JERSEY

    Energy Technology Data Exchange (ETDEWEB)

    Gary Gartenberg, P.E., P.P.

    1999-10-01

    This report represents the fourth Semi-Annual Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government--Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. During this reporting period the Engineering Design for remediation of the surface safety hazards associated with the White Meadow Mine was completed. Construction Plans and Technical Specifications were completed and competitive bids were solicited by the Township for completion of the work. The electrical resistivity survey analysis and report was completed for the Green Pond Mines site at the Township Compost Storage Facility. The geophysical survey results confirmed evidence of abandoned mining activity at the Green Pond Mine site which was previously identified. During this reporting period, the time frame of the Cooperative Agreement between the Township and the Department of Energy was extended. An additional site of subsidence with in the Township related to abandoned

  10. The Remediation of Abandoned Iron Ore Mine Subsidence in Rockaway Township, New Jersey

    Energy Technology Data Exchange (ETDEWEB)

    Gartenberg, Gary; Poff, Gregory

    2010-06-30

    This report represents the twenty-seventh and Final Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this last reporting period ending June 30, 2010 and a summary of the work accomplished since the agreement inception in 1997. This report is issued as part of the project reporting provisions set forth in the Cooperator's Agreement between the United States Government - Department of Energy, and Rockaway Township. The purpose of the Cooperator's Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the Green Pond Mine site at the Township's Jacobs Road Compost Storage Facility, surface monitoring continued after completion of construction in September 2003. Surface monitoring was conducted periodically at the Mt. Hope Road subsidence work area and adjacent areas after the January 2000 construction effort. In March 2007, a seventh collapse occurred over a portion of the White Meadow Mine in a public roadway at the intersection of Iowa and Erie Avenues in Rockaway Township. After test drilling, this portion of the mine was remediated by drilling and grouting the stopes.

  11. THE REMEDIATION OF ABANDONED IRON ORE MINE SUBSIDENCE IN ROCKAWAY TOWNSHIP, NEW JERSEY

    Energy Technology Data Exchange (ETDEWEB)

    Gary Gartenberg, P.E., P.P.

    2001-04-01

    This report represents the sixth Semi-Annual Technical Progress Report issued in connection with the subsidence remediation projects undertaken by Rockaway Township in Morris County, New Jersey. This report provides a summary of the major project work accomplished during this reporting period and contemplated for the subsequent reporting period. This report is issued as part of the project reporting provisions set forth in the Cooperators Agreement between the United States Government--Department of Energy, and Rockaway Township. The purpose of the Cooperators Agreement is for the Department of Energy to provide technical and financial assistance in a coordinated effort with Rockaway Township to develop and implement a multi-phased plan to remediate ground stability problems associated with abandoned mining activity. Primarily during the 1800's, extensive iron ore mining and prospecting was undertaken in Rockaway Township, part of the Dover District Mining region in Morris County. The abandoned mining activity has resulted in public safety hazards associated with ground collapse and surface subsidence features evolving in both developed and undeveloped areas within Rockaway Township. At the White Meadow Mine site, after amended specifications were prepared and continued negotiations took place with the Property Owner, the property ownership was transferred during the reporting period. As a result in the change in property ownership, the remediation project was then to be done by the new Property Owner out of the responsibility of Rockaway Township under this Cooperators Agreement. At the Mt. Hope Road subsidence, surface monitoring was conducted at the work area and adjacent areas after the January 2000 construction effort. At the Green Pond Mine site at the Township Compost Storage Facility, no additional field work was undertaken during this reporting period subsequent to the previous completion of the geophysical survey. With the termination of the White

  12. Flash Flood Hazard Susceptibility Mapping Using Frequency Ratio and Statistical Index Methods in Coalmine Subsidence Areas

    Directory of Open Access Journals (Sweden)

    Chen Cao

    2016-09-01

    Full Text Available This study focused on producing flash flood hazard susceptibility maps (FFHSM using frequency ratio (FR and statistical index (SI models in the Xiqu Gully (XQG of Beijing, China. First, a total of 85 flash flood hazard locations (n = 85 were surveyed in the field and plotted using geographic information system (GIS software. Based on the flash flood hazard locations, a flood hazard inventory map was built. Seventy percent (n = 60 of the flooding hazard locations were randomly selected for building the models. The remaining 30% (n = 25 of the flooded hazard locations were used for validation. Considering that the XQG used to be a coal mining area, coalmine caves and subsidence caused by coal mining exist in this catchment, as well as many ground fissures. Thus, this study took the subsidence risk level into consideration for FFHSM. The ten conditioning parameters were elevation, slope, curvature, land use, geology, soil texture, subsidence risk area, stream power index (SPI, topographic wetness index (TWI, and short-term heavy rain. This study also tested different classification schemes for the values for each conditional parameter and checked their impacts on the results. The accuracy of the FFHSM was validated using area under the curve (AUC analysis. Classification accuracies were 86.61%, 83.35%, and 78.52% using frequency ratio (FR-natural breaks, statistical index (SI-natural breaks and FR-manual classification schemes, respectively. Associated prediction accuracies were 83.69%, 81.22%, and 74.23%, respectively. It was found that FR modeling using a natural breaks classification method was more appropriate for generating FFHSM for the Xiqu Gully.

  13. The Influence of Climate, Lithology and Subsidence on the Transient Evolution of Hawaiian River Channels

    Science.gov (United States)

    Gasparini, N. M.; Menking, J. A.; Han, J.; Johnson, J. P.

    2010-12-01

    We explore channel form and evolution in the Kohala peninsula of the Big Island of Hawai’i. Incoming trade winds from the northeast create a dramatic gradient in precipitation rates, which vary from over 4000 mm/yr on the wet side to less than 250 mm/yr on the dry side of the peninsula. The region is composed of two volcanic series: the older Pololu basalt (260-450 ka), which is capped in some places by the younger Hawi series (120-260 ka). Subsidence rates in the region are about 2.5 mm/yr. We use a 10 m digital elevation model, field surveys, and a numerical model to explore the effects of these boundary conditions on the transient evolution of Kohala river channels. We find that channels on the wet side receive, on average, over ~ 1600 mm/yr of rainfall and have developed convex-concave profiles with large (10-30 m) knickpoints. In almost all cases, the largest knickpoints in the wet-side channels lie near the contact between the Hawi and Pololu series. In comparison, channels on the dry side receive, on average, less than 1600 mm/yr of rainfall and have developed nearly straight longitudinal profiles, less local relief, and smaller knickpoints. Across the peninsula a correlation exists between greater concavity indices and higher mean annual precipitation, as well as between higher local relief along the channel and higher mean annual precipitation. While knickpoint propagation clearly influences channel evolution, numerical simulations using a one-dimensional channel profile evolution model that includes only the stream-power model suggest that the precipitation pattern and subsidence boundary condition may significantly contribute to the convex-concave form of wet-side channels. All of these observations suggest that rainfall patterns play an important role in transient channel evolution, but that changes in lithology and subsidence also significantly impact the form of the channel profile.

  14. Land Subsidence in Chiayi, Taiwan, from Compaction Well, Leveling and ALOS/PALSAR: Aquaculture-Induced Relative Sea Level Rise

    Directory of Open Access Journals (Sweden)

    Wei-Chia Hung

    2017-12-01

    Full Text Available Chiayi County is located in the largest alluvial plain of Taiwan with extensive aquaculture and rice farming sustained by water extracted from groundwater wells. Chiayi is a typical aquaculture area affected by land subsidence, yet such lands worldwide combine to provide nearly 90% of global aquaculture products, greatly reducing oceanic overfishing problems. This study uses precision leveling, multi-layer compaction monitoring well (MLCW and spaceborne SAR interferometry (InSAR to examine the cause and effect of land subsidence in Chiayi associated with groundwater extractions and changes. Heights at benchmarks in a leveling network are measured annually and soil compactions at 24–26 layers up to 300-m depths at 7 MLCWs are collected at one-month intervals. Over 2007–2011, 15 ALOS/PALSAR images are processed by the method of TCPInSAR to produce subsidence rates. All sensors show that land subsidence occur in most parts of Chiayi, with rates reaching 4.5 cm/year around its coast, a result of groundwater pumping from shallow to deep aquifers. MLCWs detect mm-accuracy seasonal soil compactions coinciding with groundwater level fluctuations and causing dynamic compactions. Compactions near Taiwan High Speed Rail may reduce the strength of the rail’s supporting columns to degrade its safety. The SAR images yield subsidence rates consistent with those from leveling and compaction wells after corrections for systematic errors by the leveling result. Subsidence in Chiayi’s coastal area leads to relative sea level rises at rates up to 15 times larger than the global eustatic sea level rising rate, a risk typical for world’s aquaculture-rich regions. At the fish pond-covered Budai Township, InSAR identifies subsidence spots not detected by leveling, providing crucial geo-information for a sustainable land management for aquaculture industry.

  15. Subsidence history of the city of Morelia, Mexico based on InSAR images processed as time series

    Science.gov (United States)

    Jaramillo, S. H.; Suárez, G.; López-Quiroz, P.

    2012-04-01

    The city of Morelia in central Mexico sits on lacustrine and fluvio-lacustrine deposits. Subsidence due to the extraction of water from the subsoil is evidenced by the presence of differential soil compaction, causing faulting and cracking of the ground and adjacent constructions. In order to study the subsidence history of the past nine years, twenty-eight ENVISAT Synthetic Aperture Radar (SAR) images acquired between May 2003 and September 2010 were processed using ROI_PAC. All scenes are descending orbit images. The resulting interferograms were filtered using an adaptive filter and, in order to increase coherence and signal-to-noise ratio, they were unwrapped using the "branch-cut" algorithm. A subset of the resulting interferograms was selected based on the following criteria. Only interferograms with spatial baseline of less than 400 m and a temporal baseline of less than 420 days were considered. The primary objective of our work was to determine the temporal evolution of the subsidence in different parts of the city. To this end, selected pixels are inverted in an independent manner from neighbouring pixels using a time series analysis. Preliminary results suggest that the central part of the basin, near the fault known as the "Central Camionera", the subsidence is almost constant with a value of 3 to 4 cm/yr until 2008. From this date on, the subsidence rates increase to values with an average of 7 to 8 cm/yr. This increase in the subsidence rate is clearly appreciated in the appearance of two clearly visible circular patterns from 2008 to 2010. Currently, an inversion is being conducted to obtain the overall subsidence history of the basin.

  16. Land subsidence induced by groundwater extraction and building damage level assessment - a case study of Datun, China

    Energy Technology Data Exchange (ETDEWEB)

    Qi-yan Feng; Gang-jun Liu; Lei Meng; Er-jiang Fu; Hai-rong Zhang; Ke-fei Zhang [China University of Mining and Technology, Xuzhou (China). Jiangsu Key Laboratory of Resources and Environmental Information Engineering

    2008-12-15

    As in many parts of the world, long-term excessive extraction of groundwater has caused significant land-surface subsidence in the residential areas of Datun coal mining district in East China. The recorded maximum level of subsidence in the area since 1976 to 2006 is 863 mm, and the area with an accumulative subsidence more than 200 mm reached 33.1 km{sup 2} by the end of 2006. Over ten cases of building crack due to ground subsidence have already been observed. Spatial variation in ground subsidence often leads to a corresponding pattern of ground deformation. Buildings and underground infrastructures have been under a higher risk of damage in locations with greater differential ground deformation. Governmental guideline in China classifies building damages into four different levels, based on the observable measures such as the width of wall crack, the degree of door and window deformation, the degree of wall inclination and the degree of structural destruction. Building damage level (BDL) is estimated by means of ground deformation analysis in terms of variations in slope gradient and curvature. Ground deformation analysis in terms of variations in slope gradient has shown that the areas of BDL III and BDL II sites account for about 0.013 km{sup 2} and 0.284 km{sup 2} respectively in 2006, and the predicted areas of BDL (define this first) III and II sites will be about 0.029 km{sup 2} and 0.423 km{sup 2} respectively by 2010. The situation is getting worse as subsidence continues. That calls for effective strategies for subsidence mitigation and damage reduction, in terms of sustainable groundwater extraction, enhanced monitoring and the establishment of early warning systems. 12 refs., 6 figs., 1 tab.

  17. Combination of poroelasticity theory and constant strain rate test in modelling land subsidence due to groundwater extraction

    Science.gov (United States)

    Pham, Tien Hung; Rühaak, Wolfram; Sass, Ingo

    2017-04-01

    Extensive groundwater extraction leads to a drawdown of the ground water table. Consequently, soil effective stress increases and can cause land subsidence. Analysis of land subsidence generally requires a numerical model based on poroelasticity theory, which was first proposed by Biot (1941). In the review of regional land subsidence accompanying groundwater extraction, Galloway and Burbey (2011) stated that more research and application is needed in coupling of stress-dependent land subsidence process. In geotechnical field, the constant rate of strain tests (CRS) was first introduced in 1969 (Smith and Wahls 1969) and was standardized in 1982 through the designation D4186-82 by American Society for Testing and Materials. From the reading values of CRS tests, the stress-dependent parameters of poroelasticity model can be calculated. So far, there is no research to link poroelasticity theory with CRS tests in modelling land subsidence due to groundwater extraction. One dimensional CRS tests using conventional compression cell and three dimension CRS tests using Rowe cell were performed. The tests were also modelled by using finite element method with mixed elements. Back analysis technique is used to find the suitable values of hydraulic conductivity and bulk modulus that depend on the stress or void ratio. Finally, the obtained results are used in land subsidence models. Biot, M. A. (1941). "General theory of three-dimensional consolidation." Journal of applied physics 12(2): 155-164. Galloway, D. L. and T. J. Burbey (2011). "Review: Regional land subsidence accompanying groundwater extraction." Hydrogeology Journal 19(8): 1459-1486. Smith, R. E. and H. E. Wahls (1969). "Consolidation under constant rates of strain." Journal of Soil Mechanics & Foundations Div.

  18. Scientists Focus on Land Subsidence Impacts on Coastal and Delta Cities

    Science.gov (United States)

    Showstack, Randy

    2014-05-01

    Some coastal and delta cities around the world are sinking but not necessarily due only to sea level rise and impacts from extreme weather events. Land subsidence that is caused by anthropogenic processes—including the extraction of groundwater, oil, and gas and the drainage of soils—is a significant concern for Jakarta, Indonesia; Manila, Philippines; New Orleans, La.; and many other coastal and delta cities, according to scientists at a 28 April briefing held at the European Geosciences Union's General Assembly in Vienna, Austria.

  19. Regional variations in subsidence rate of lithospheric plates: implication for thermal cooling models

    Science.gov (United States)

    Lago, Bernard; Cazenave, Anny; Marty, Jean-Charles

    Although simple thermal models of lithospheric cooling predict to first order the general behaviour of observed seafloor depth with increasing age, important regional variations in seafloor subsidence, in the range 250-400 m Ma1/2, are reported for several lithospheric plates. Such variations cannot be accounted for by classical cooling models unless implausible variations in asthenospheric temperature of ˜550°C are assumed. Here we present an alternative cooling model, which assumes that at the ridge axis the temperature may deviate from the mean asthenospheric temperature. Such a model satisfactorily explains the data provided that the temperature deviation is ±100°C only.

  20. Gulf Coast Subsidence: Crustal Loading, Geodesy, and Recent InSAR and UAVSAR Observations

    Science.gov (United States)

    Blom, R. G.; Dokka, R. K.; Fielding, E. J.; Hawkins, B. P.; Hensley, S.; Ivins, E. R.; Jones, C. E.; Lohman, R. B.; Zheng, Y.

    2011-12-01

    The vulnerability of the Gulf Coast has received increasing attention in the years since hurricanes Katrina and Rita. A quantitative geophysical basis for measuring, predicting, and understanding subsidence rates, their geographic distribution, and temporal variability, is necessary for long term protection of lives and property in addition to being a challenging scientific problem. Analysis of historical and continuing geodetic measurements identifies a surprising degree of complexity in subsidence, including regions that are subsiding at rates faster than those considered during planning for hurricane protection of New Orleans and other population centers (http://www.mvn.usace.army.mil/pdf/hps_verticalsettlement.pdf), and for coastal restoration planning for coastal Louisiana (http://www.coast2050.gov/2050reports.htm) (Dokka, 2011, J. Geophys. Res., 116, B06403, doi:10.1029/2010JB008008). Meanwhile, traditional geodetic data provide precise information at single points, InSAR observations provide geographically dense constraints on surface deformation. Available radar data sources include C and L band satellite, and NASA/JPL airborne UAVSAR L band data. The Gulf Coast environment is very challenging for InSAR techniques, especially with systems not designed for interferometry. The shorter wavelength C band data decorrelates over short time periods necessitating more elaborate analysis techniques. We have early results from new persistent scatterer methods and masking techniques to eliminate areas affected by water level changes, all applied to C-band satellite radar data. Limited L-Band ALOS/PALSAR satellite data are available for analysis using conventional interferometry, unfortunately this Japanese satellite system recently failed. Most importantly, we now have airborne UAVSAR repeat pass interferometry data sets spanning a total interval of 514 days (http://uavsar.jpl.nasa.gov/). These data can constrain geophysical models of crustal behavior, leading to

  1. Small subsidence of the 660-km discontinuity beneath Japan probed by ScS reverberations

    Science.gov (United States)

    Kato, Mamoru; Misawa, Mika; Kawakatsu, Hitoshi

    We investigate layering structure in the mantle beneath Japan using ScS reverberation waveforms of two recent large deep events in the northwest Pacific. We estimate regional variation of the elastic and anelastic structure of the mantle as well as properties of the major velocity discontinuities by modeling broadband seismograms recorded at two dense networks, J-Array and FREESIA. The 660-km discontinuity is the deepest in the region where the stagnant subducting slab in the transition zone is tomographically imaged, but the subsidence is of ∼10 km, much smaller than previous estimates with SS precursors. No significant elevation is detected for the 410-km discontinuity.

  2. Evolutionary dynamics of a rapidly receding southern range boundary in the threatened California red-legged frog (Rana draytonii)

    Science.gov (United States)

    Richmond, Jonathan Q.; Barr, Kelly R.; Backlin, Adam R.; Vandergast, Amy G.; Fisher, Robert N.

    2013-01-01

    Populations forming the edge of a species range are often imperiled by isolation and low genetic diversity, with proximity to human population centers being a major determinant of edge stability in modern landscapes. Since the 1960s, the California red-legged frog (Rana draytonii) has undergone extensive declines in heavily urbanized southern California, where the range edge has rapidly contracted northward while shifting its cardinal orientation to an east-west trending axis. We studied the genetic structure and diversity of these frontline populations, tested for signatures of contemporary disturbance, specifically fire, and attempted to disentangle these signals from demographic events extending deeper into the past. Consistent with the genetic expectations of the ‘abundant-center’ model, we found that diversity, admixture, and opportunity for random mating increases in populations sampled successively further away from the range boundary. Demographic simulations indicate that bottlenecks in peripheral isolates are associated with processes extending tens to a few hundred generations in the past, despite the demographic collapse of some due to recent fire-flood events. While the effects of recent disturbance have left little genetic imprint on these populations, they likely contribute to an extinction debt that will lead to continued range contraction unless management intervenes to stall or reverse the process.

  3. DInSAR-Based Detection of Land Subsidence and Correlation with Groundwater Depletion in Konya Plain, Turkey

    Directory of Open Access Journals (Sweden)

    Fabiana Caló

    2017-01-01

    Full Text Available In areas where groundwater overexploitation occurs, land subsidence triggered by aquifer compaction is observed, resulting in high socio-economic impacts for the affected communities. In this paper, we focus on the Konya region, one of the leading economic centers in the agricultural and industrial sectors in Turkey. We present a multi-source data approach aimed at investigating the complex and fragile environment of this area which is heavily affected by groundwater drawdown and ground subsidence. In particular, in order to analyze the spatial and temporal pattern of the subsidence process we use the Small BAseline Subset DInSAR technique to process two datasets of ENVISAT SAR images spanning the 2002–2010 period. The produced ground deformation maps and associated time-series allow us to detect a wide land subsidence extending for about 1200 km2 and measure vertical displacements reaching up to 10 cm in the observed time interval. DInSAR results, complemented with climatic, stratigraphic and piezometric data as well as with land-cover changes information, allow us to give more insights on the impact of climate changes and human activities on groundwater resources depletion and land subsidence.

  4. Advanced interpretation of subsidence in Murcia (SE Spain) using A-DInSAR data - modelling and validation

    Science.gov (United States)

    Herrera, G.; Fernández, J. A.; Tomás, R.; Cooksley, G.; Mulas, J.

    2009-05-01

    Subsidence is a natural hazard that affects wide areas in the world causing important economic costs annually. This phenomenon has occurred in the metropolitan area of Murcia City (SE Spain) as a result of groundwater overexploitation. In this work aquifer system subsidence is investigated using an advanced differential SAR interferometry remote sensing technique (A-DInSAR) called Stable Point Network (SPN). The SPN derived displacement results, mainly the velocity displacement maps and the time series of the displacement, reveal that in the period 2004-2008 the rate of subsidence in Murcia metropolitan area doubled with respect to the previous period from 1995 to 2005. The acceleration of the deformation phenomenon is explained by the drought period started in 2006. The comparison of the temporal evolution of the displacements measured with the extensometers and the SPN technique shows an average absolute error of 3.9±3.8 mm. Finally, results from a finite element model developed to simulate the recorded time history subsidence from known water table height changes compares well with the SPN displacement time series estimations. This result demonstrates the potential of A-DInSAR techniques to validate subsidence prediction models as an alternative to using instrumental ground based techniques for validation.

  5. Development of a complex groundwater model to assess the relation among groundwater resource exploitation, seawater intrusion and land subsidence

    Science.gov (United States)

    Hsi Ting, Fang; Yih Chi, Tan; Chen, Jhong Bing

    2016-04-01

    The land subsidence, which is usually irreversible, in Taiwan Pintung Plain occurred due to groundwater overexploitation. Many of the land subsidence areas in Taiwan are located in coastal area. It could not only result in homeland loss, but also vulnerability to flooding because the function of drainage system and sea wall are weakened for the lowered ground surface. Groundwater salinization and seawater intrusion could happen more easily as well. This research focuses on grasping the trend of environmental change due to the damage and impact from inappropriate development of aquaculture in the last decades. The main task is developing the artificial neural networks (ANNs) and complex numerical model for conjunctive use of surface and groundwater which is composed of a few modules such as land use, land subsidence, contamination transportation and etc. An approach based on self-organizing map (SOM) is proposed to delineate groundwater recharge zones. Several topics will be studied such as coupling of surface water and groundwater modeling, assessing the benefit of improving groundwater resources by recharge, identifying the improper usage of groundwater resources, and investigating the effect of over-pumping on land subsidence in different depth. In addition, a complete plan for managing both the flooding and water resources will be instituted by scheming non-engineering adaptation strategies for homeland planning, ex. controlling pumping behavior in area vulnerable to land subsidence and increasing groundwater recharge.

  6. Different scale land subsidence and ground fissure monitoring with multiple InSAR techniques over Fenwei basin, China

    Directory of Open Access Journals (Sweden)

    C. Zhao

    2015-11-01

    Full Text Available Fenwei basin, China, composed by several sub-basins, has been suffering severe geo-hazards in last 60 years, including large scale land subsidence and small scale ground fissure, which caused serious infrastructure damages and property losses. In this paper, we apply different InSAR techniques with different SAR data to monitor these hazards. Firstly, combined small baseline subset (SBAS InSAR method and persistent scatterers (PS InSAR method is used to multi-track Envisat ASAR data to retrieve the large scale land subsidence covering entire Fenwei basin, from which different land subsidence magnitudes are analyzed of different sub-basins. Secondly, PS-InSAR method is used to monitor the small scale ground fissure deformation in Yuncheng basin, where different spatial deformation gradient can be clearly discovered. Lastly, different track SAR data are contributed to retrieve two-dimensional deformation in both land subsidence and ground fissure region, Xi'an, China, which can be benefitial to explain the occurrence of ground fissure and the correlation between land subsidence and ground fissure.

  7. Long Wavelenth Subsidence of Western Europe during Late Eocene-Oligocene (38-23 Ma): Mantle Dynamic Effect?

    Science.gov (United States)

    Guillocheau, Francois; Robin, Cécile; Bessin, Paul

    2015-04-01

    Western Europe (France, southern Britain, southern Belgium, western Germany) is subsiding during Late Eocene to Oligocene (38-23 Ma) as suggested by the growth of numerous small sedimentary basins mainly filled by lacustrine deposits with some brackish to marine deposits. This large-scale subsidence is coeval with the early stage of the so-called Oligocene rifts (in fact Late Bartonian to Rupelian): Lower Rhinegraben, Bresse, Limagnes. The subsiding domain extends from Cornwall to the Rhine Graben including the Armorican Massif, the southern Paris Basin, the northern Aquitaine Basin, the French Central Massif, the Ardennes-Eifel… This subsidence occurred at a period of global sea level fall and then an eustatic component cannot explain (1) the accommodation space creation and (2) the marine floding with a paroxysm during Early Oligocene times (Armorican Massif, ?Ardennes, French Massif central). This marine flooding also indicate that the relief of the Hercynian basement was less elevated and smoother than today. Some of those small "basins" were interpreted as little rifts, but new mapping (e.g. Puy-en-Velay or Forez Plain in the French Massif central) or new geophysical data (e.g. Rennes Basin in the Armorican massif) suggest that no faults control those basins or that they result from post-depositional collapses. This long wavelength subsidence is at the scale of the mantle dynamic. Possible mantle mechanisms and the relationships with the "Oligocene" rifts and the North Sea inversion will be discussed.

  8. Quaternary development of resilient reefs on the subsiding kimberley continental margin, Northwest Australia

    Directory of Open Access Journals (Sweden)

    Lindsay B. Collins

    2010-01-01

    Full Text Available The Kimberley region in remote northwest Australia has poorly known reef systems of two types; coastal fringing reefs and atoll-like shelf-edge reefs. As a major geomorphic feature (from 12ºS to 18ºS situated along a subsiding continental margin, the shelf edge reefs are in a tropical realm with warm temperatures, relatively low salinity, clear low nutrient waters lacking sediment input, and Indo-West Pacific corals of moderate diversity. Seismic architecture of the Rowley Shoals reveals that differential pre-Holocene subsidence and relative elevation of the pre-Holocene substrate have controlled lagoon sediment infill and reef morphology, forming an evolutionary series reflecting differential accommodation in three otherwise similar reef systems. The Holocene core described for North Scott Reef confirms previous seismic interpretations, and provides a rare ocean-facing reef record. It demonstrates that the Indo-Pacific reef growth phase (RG111 developed during moderate rates of sea level rise of 10 mm/year from 11 to about 7-6.5 ka BP until sea level stabilization, filling the available 27 m of pre-Holocene accommodation. Despite the medium to high hydrodynamic energy imposed by the 4m tides, swell waves and cyclones the reef-building communities represent relatively low-wave energy settings due to their southeast facing and protection afforded by the proximity of the South Reef platform. This study demonstrates the resilience of reefs on the subsiding margin whilst linking Holocene reef morphology to the relative amount of pre-Holocene subsidence.Kimberly é uma região remota e pouco conhecida, localizada no noroeste da Austrália, ali são encontrados dois sistemas recifais: recifes costeiros de franja e os tipo-atois localizados na margem da plataforma continental. Esses recifes formam a feição geomórfica mais importante entre 12ºS a 18ºS estando localizados ao longo de uma margem continental em subsidência. Esses recifes encontram

  9. Geodetic monitoring of subrosion-induced subsidence processes in urban areas

    Science.gov (United States)

    Kersten, Tobias; Kobe, Martin; Gabriel, Gerald; Timmen, Ludger; Schön, Steffen; Vogel, Detlef

    2017-03-01

    The research project SIMULTAN applies an advanced combination of geophysical, geodetic, and modelling techniques to gain a better understanding of the evolution and characteristics of sinkholes. Sinkholes are inherently related to surface deformation and, thus, of increasing societal relevance, especially in dense populated urban areas. One work package of SIMULTAN investigates an integrated approach to monitor sinkhole-related mass translations and surface deformations induced by salt dissolution. Datasets from identical and adjacent points are used for a consistent combination of geodetic and geophysical techniques. Monitoring networks are established in Hamburg and Bad Frankenhausen (Thuringia). Levelling surveys indicate subsidence rates of about 4-5 mm per year in the main subsidence areas of Bad Frankenhausen with a local maximum of 10 mm per year around the leaning church tower. Here, the concept of combining geodetic and gravimetric techniques to monitor and characterise geological processes on and below the Earth's surface is exemplary discussed for the focus area Bad Frankenhausen. For the different methods (levelling, GNSS, relative/absolute gravimetry) stable network results at identical points are obtained by the first campaigns, i.e., the results are generally in agreement.

  10. Predicting family reunification, adoption, and subsidized guardianship among adolescents in foster care.

    Science.gov (United States)

    Leathers, Sonya J; Falconnier, Lydia; Spielfogel, Jill E

    2010-07-01

    Although national legislation has attempted to decrease the length of time that children spend in foster care, these policies have been less effective with adolescents than with children, raising questions about how best to promote permanency for adolescents. This study examined factors that predict adolescent adoption, subsidized guardianship, and reunification. The caseworkers and foster parents of 203 randomly selected 12- to 13-year-olds placed in traditional or specialized foster care were interviewed. Permanency outcomes were prospectively tracked for 8 years. By the end of the study, over 40% of the adolescents were placed in permanent homes. As hypothesized, a strong relationship with a biological mother predicted successful reunification, and a high degree of integration into a foster home predicted adoption. Additionally, when compared with adoption, subsidized guardianship with foster parents occurred more frequently for youth with strong relationships with their biological mothers and weaker relationships with their foster families. Unexpectedly, behavior problems were not related to any permanency outcomes. Results suggest that promotion of strong relationships with adults is the key in efforts to find permanent families for foster children. Furthermore, efforts to attain permanency should not cease during adolescence.

  11. Catastrophic isotopic modification of rhyolitic magma at times of caldera subsidence, Yellowstone plateau volcanic field.

    Science.gov (United States)

    Hildreth, W.; Christiansen, R.L.; O'Neil, J.R.

    1984-01-01

    This Wyoming volcanic field has undergone repeated eruption of rhyolitic magma strongly depleted in 18O. Large calderas subsided 2.0, 1.3 and 0.6 m.y. ago on eruption of ash-flow sheets. More than 60 other rhyolite lavas and tuffs permit reconstruction of the long-term chemical and isotopic evolution of the silicic system. Narrow delta 18O ranges in the ash-flow sheets contrast with wide delta 18O variation in post-caldera lavas. The earliest post-collapse lavas are 3-6per mille lighter than the preceding ash-flow sheets. The 18O depletions were short-lived events that immediately followed caldera subsidence and sequences of post-caldera lavas record partial recovery toward pre-caldera delta 18O values. Contemporaneous extra-caldera rhyolites show no effects of the repeated depletions. Although some contamination by foundering roof rocks seems to be required, water was probably the predominant contaminant.-W.H.B.

  12. Continental margin subsidence from shallow mantle convection: Example from West Africa

    Science.gov (United States)

    Lodhia, Bhavik Harish; Roberts, Gareth G.; Fraser, Alastair J.; Fishwick, Stewart; Goes, Saskia; Jarvis, Jerry

    2018-01-01

    Spatial and temporal evolution of the uppermost convecting mantle plays an important role in determining histories of magmatism, uplift, subsidence, erosion and deposition of sedimentary rock. Tomographic studies and mantle flow models suggest that changes in lithospheric thickness can focus convection and destabilize plates. Geologic observations that constrain the processes responsible for onset and evolution of shallow mantle convection are sparse. We integrate seismic, well, gravity, magmatic and tomographic information to determine the history of Neogene-Recent (water-loaded subsidence occurred in a ∼500 × 500 km region centered on the Mauritania basin during the last 23 Ma. Conversion of shear wave velocities into temperature and simple isostatic calculations indicate that asthenospheric temperatures determine bathymetry from Cape Verde to West Africa. Calculated average excess temperatures beneath Cape Verde are > + 100 °C providing ∼103 m of support. Beneath the Mauritania basin average excess temperatures are < - 100 °C drawing down the lithosphere by ∼102 to 103 m. Up- and downwelling mantle has generated a bathymetric gradient of ∼1/300 at a wavelength of ∼103 km during the last ∼23 Ma. Our results suggest that asthenospheric flow away from upwelling mantle can generate downwelling beneath continental margins.

  13. The Research on Subsidence Prediction of Soils Around Deep Foundation Pit

    Directory of Open Access Journals (Sweden)

    Ge LIU

    2014-12-01

    Full Text Available Deep foundation pit will cause settlement of surround buildings in the process of excavation. When the settlement is excessive, it will give rise to safety issues. Subsidence monitoring has become an important measure to ensure the safety of deep foundation pits. But in current subsidence monitoring engineering, the costs of wiring, unwiring and installation are particularly high. This paper proposes a portable wireless data transmission device in forecasting and early warning of settlement deformation of soils around deep foundation pits. We solve the problem by adopting the means of wireless communication to replace the cable transmission link part. The device does not rely on any personal computers. Instead, it can directly deal with the collected data through grey prediction GM (1, 1 mathematical model, neural network and interpolation model to give short-term, medium- term and long-term forecasts, respectively. Additionally it is able to set a threshold value. Once the forecast data reach the threshold, the device can issue alert and achieve the target of reminding technicians, so as to provide reliable basis to prevent and reduce disasters.

  14. Man in Louisiana's coastal zone - From reclamation to subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Davis, D.W. (Louisiana Geological Survey, Baton Rouge (USA))

    1990-09-01

    For more than 300 years the US marsh lands were thought to be of no economic value. They were considered useless wastelands. Today, they are recognized as valuable and highly productive environments. As a renewable resource that operates with minimum capital expenditures, the wetlands are epitomized in Louisiana. Even so, south Louisiana's first settlers were unaware of the wetlands value. These coastal lowlands were considered a nuisance. They bred yellow fever-carrying mosquitos and contributed directly and indirectly to flooding. Consequently, to overcome the hardships of being sea-level citizens, for more than 250 years the inhabitants have systematically reclaimed the marshes and swamps. As a result of the intense utilization of levees and pumps, normally wet property began to dry out, losing some of its natural buoyancy, increasing regional subsidence. Man-induced negative land surfaces are producing an urbanized population that must face the realities of subsidence caused by unregulated reclamation. New Orleans has, in fact, become North America's premier sinking city. The population has been forced to learn how to live with the problem. Nevertheless, these people are at risk, particularly if the current predicted sea-level rise of 1.2 mm/yr is correct. In the main, Louisiana's coastal issues will become those of the nation and represent the precursor of things to come. Louisiana's reaction and solutions to these issues will establish a precedent for the remainder of the country to follow.

  15. Highway Subsidence Analysis Based on the Advanced InSAR Time Series Analysis Method

    Science.gov (United States)

    Zhang, Qingyun; Zhang, Jingfa; Liu, Guolin; Li, Yongsheng

    2016-08-01

    The synthetic aperture radar (InSAR) measurements have the advantages of all-weather, wide range, high precision on the surface deformation monitoring. Highway as an important index of modern social and economic development, the quality and deformation changes in the process of using have a significant impact in the social development and people's life and property security. In practical applications the InSAR technology should do a variety of error correction analysis. By using a new analysis method - FRAM- SBAS time-series analysis method, to analyze the settlement of highway on Yanzhou area by the ALOS PALSAR datas. Use FRAM- SBAS timing analysis method to obtain the surface timing changes during 2008-09-21 to 2010-07-18 in the Jining area and obtained good results, the Jining area maximum timing settlement is 60mm, the maximum settlement rate reached 30mm/yr. The maximum settlement of the highway section is 53mm, the maximum settlement rate is 32mm/yr. And the settlement of highway worst sections were in severe ground subsidence, thus proving the mining and vehicle load effect on settlement of highway. And it is proved that the timing method on the ground and highway subsidence monitoring is feasible.

  16. Kalman Filters in Geotechnical Monitoring of Ground Subsidence Using Data from MEMS Sensors.

    Science.gov (United States)

    Li, Cheng; Azzam, Rafig; Fernández-Steeger, Tomás M

    2016-07-19

    The fast development of wireless sensor networks and MEMS make it possible to set up today real-time wireless geotechnical monitoring. To handle interferences and noises from the output data, Kalman filter can be selected as a method to achieve a more realistic estimate of the observations. In this paper, a one-day wireless measurement using accelerometers and inclinometers was deployed on top of a tunnel section under construction in order to monitor ground subsidence. The normal vectors of the sensors were firstly obtained with the help of rotation matrices, and then be projected to the plane of longitudinal section, by which the dip angles over time would be obtained via a trigonometric function. Finally, a centralized Kalman filter was applied to estimate the tilt angles of the sensor nodes based on the data from the embedded accelerometer and the inclinometer. Comparing the results from two sensor nodes deployed away and on the track respectively, the passing of the tunnel boring machine can be identified from unusual performances. Using this method, the ground settlement due to excavation can be measured and a real-time monitoring of ground subsidence can be realized.

  17. Basic overview towards the assessment of landslide and subsidence risks along a geothermal pipeline network

    Science.gov (United States)

    Astisiasari; Van Westen, Cees; Jetten, Victor; van der Meer, Freek; Rahmawati Hizbaron, Dyah

    2017-12-01

    An operating geothermal power plant consists of installation units that work systematically in a network. The pipeline network connects various engineering structures, e.g. well pads, separator, scrubber, and power station, in the process of transferring geothermal fluids to generate electricity. Besides, a pipeline infrastructure also delivers the brine back to earth, through the injection well-pads. Despite of its important functions, a geothermal pipeline may bear a threat to its vicinity through a pipeline failure. The pipeline can be impacted by perilous events like landslides, earthquakes, and subsidence. The pipeline failure itself may relate to physical deterioration over time, e.g. due to corrosion and fatigue. The geothermal reservoirs are usually located in mountainous areas that are associated with steep slopes, complex geology, and weathered soil. Geothermal areas record a noteworthy number of disasters, especially due to landslide and subsidence. Therefore, a proper multi-risk assessment along the geothermal pipeline is required, particularly for these two types of hazard. This is also to mention that the impact on human fatality and injury is not presently discussed here. This paper aims to give a basic overview on the existing approaches for the assessment of multi-risk assessment along geothermal pipelines. It delivers basic principles on the analysis of risks and its contributing variables, in order to model the loss consequences. By considering the loss consequences, as well as the alternatives for mitigation measures, the environmental safety in geothermal working area could be enforced.

  18. Predicting Family Reunification, Adoption, and Subsidized Guardianship Among Adolescents in Foster Care

    Science.gov (United States)

    Leathers, Sonya J.; Falconnier, Lydia; Spielfogel, Jill E.

    2010-01-01

    Although national legislation has attempted to decrease the length of time that children spend in foster care, these policies have been less effective with adolescents than with children, raising questions about how best to promote permanency for adolescents. This study examined factors that predict adolescent adoption, subsidized guardianship, and reunification. The caseworkers and foster parents of 203 randomly selected 12-13 year olds placed in traditional or specialized foster care were interviewed. Permanency outcomes were prospectively tracked for eight years. By the end of the study, over 40% of the adolescents were placed in permanent homes. As hypothesized, a strong relationship with a biological mother predicted successful reunification, and a high degree of integration into a foster home predicted adoption. Additionally, as compared to adoption, subsidized guardianship with foster parents occurred more frequently for youth with strong relationships with their biological mothers and weaker relationships with their foster families. Unexpectedly, behavior problems were not related to any permanency outcomes. Results suggest that promotion of strong relationships with adults is key in efforts to find permanent families for foster children. Furthermore, efforts to attain permanency should not cease during adolescence. PMID:20636947

  19. Inequality in oral health-related quality of life before and after a major subsidization reform.

    Science.gov (United States)

    Raittio, Eero; Lahti, Satu; Kiiskinen, Urpo; Helminen, Sari; Aromaa, Arpo; Suominen, Anna L

    2015-08-01

    In Finland, a dental subsidization reform, implemented in 2001-2002, abolished age restrictions on subsidized dental care. We investigated income-related inequality in oral health-related quality of life (OHRQoL) and its determinants among adult Finns before and after the reform. Three cross-sectional postal surveys, focusing on perceived oral health and the use of dental services among people born before 1971, were conducted in 2001 (n = 2,046), 2004 (n = 1,728), and 2007 (n = 1,560). Five measures, based on the Oral Health Impact Profile-14, were used as indicators of OHRQoL. Income-related inequality and associated factors were analysed using the concentration index and its decomposition. Prevalence, extent, and severity of oral health impacts were slightly lower in 2007 than in 2001. The oral health impacts were concentrated, at all study time points, among individuals with lower income. Most of the inequality was related to self-perceived general health, tooth loss, and income. Contributions of time since the last dental visit and satisfaction with the last treatment period to the inequality decreased from 2001 to 2007. However, the contributions of these factors were already small (10-20%) in 2001. In general, OHRQoL improved slightly; however, no clear or dramatic change in inequality in OHRQoL was seen after the reform. © 2015 Eur J Oral Sci.

  20. Subsidence at Dallol proto-volcano, Afar (Ethiopia): cooling of the magma chamber or deep interconnection?

    Science.gov (United States)

    Meuti, Stefano; Pagli, Carolina; Pepe, Susi; Battaglia, Maurizio; Casu, Francesco; De Luca, Claudio; Pepe, Antonio

    2017-04-01

    In this work we study the crustal deformation at Dallol proto-volcano, the seventh volcanic centre of the Erta Ale range (Northern Afar, Ethiopia), employing InSAR data acquired by the ENVISAT and Sentinel-1 satellites between 2005 - 2015. This was done to continue to monitor the long term at Dallol after the dike intrusion event in October 2004. The intrusion was fed by a magma chamber under at 2.4 Km depth. After this event no significant deformation has been detected at Dallol. We analyzed SAR images acquired by ENVISAT between January 2005 and February 2010. We also processed a time series of SAR images acquired by SENTINEL-1 satellite for the period ranging from March 2015 to December 2015. The ENVISAT data show a circular deformation pattern around Dallol volcano from October 2008 to February 2010. Sentinel data show the same deformation trend from March 2015 to December 2015. This deformation pattern is a clear increase in the line-of-sight distance (LOS) from the sensor to the target, defining a long term subsidence pattern at Dallol. The results of the inversion of InSAR measurements show that, for the ENVISAT acquisition, the sill source is the best fitting source geometry to explain the Dallol subsidence deformation. The results reveal a source depth of 1284 ± 343 m, located under the volcano. The source has a volume variation of -5.9 ± 0.6 10e5 mc.

  1. Increased Primary Production from an Exotic Invader Does Not Subsidize Native Rodents.

    Directory of Open Access Journals (Sweden)

    Jacob E Lucero

    Full Text Available Invasive plants have tremendous potential to enrich native food webs by subsidizing net primary productivity. Here, we explored how a potential food subsidy, seeds produced by the aggressive invader cheatgrass (Bromus tectorum, is utilized by an important guild of native consumers--granivorous small mammals--in the Great Basin Desert, USA. In a series of field experiments we examined 1 how cheatgrass invasion affects the density and biomass of seed rain at the ecosystem-level; 2 how seed resources from cheatgrass numerically affect granivorous small mammals; and 3 how the food preferences of native granivores might mediate the trophic integration of cheatgrass seeds. Relative to native productivity, cheatgrass invasion increased the density and biomass of seed rain by over 2000% (P < 0.01 and 3500% (P < 0.01, respectively. However, granivorous small mammals in native communities showed no positive response in abundance, richness, or diversity to experimental additions of cheatgrass seeds over one year. This lack of response correlated with a distinct preference for seeds from native grasses over seeds from cheatgrass. Our experiments demonstrate that increased primary productivity associated with exotic plant invasions may not necessarily subsidize consumers at higher trophic levels. In this context, cheatgrass invasion could disrupt native food webs by providing less-preferred resources that fail to enrich higher trophic levels.

  2. Kalman Filters in Geotechnical Monitoring of Ground Subsidence Using Data from MEMS Sensors

    Directory of Open Access Journals (Sweden)

    Cheng Li

    2016-07-01

    Full Text Available The fast development of wireless sensor networks and MEMS make it possible to set up today real-time wireless geotechnical monitoring. To handle interferences and noises from the output data, Kalman filter can be selected as a method to achieve a more realistic estimate of the observations. In this paper, a one-day wireless measurement using accelerometers and inclinometers was deployed on top of a tunnel section under construction in order to monitor ground subsidence. The normal vectors of the sensors were firstly obtained with the help of rotation matrices, and then be projected to the plane of longitudinal section, by which the dip angles over time would be obtained via a trigonometric function. Finally, a centralized Kalman filter was applied to estimate the tilt angles of the sensor nodes based on the data from the embedded accelerometer and the inclinometer. Comparing the results from two sensor nodes deployed away and on the track respectively, the passing of the tunnel boring machine can be identified from unusual performances. Using this method, the ground settlement due to excavation can be measured and a real-time monitoring of ground subsidence can be realized.

  3. Guidelines for sinkhole and subsidence rehabilitation based on generic geological models of a dolomite environment on the East Rand, South Africa

    Science.gov (United States)

    Kleinhans, Ilse; Van Rooy, J. Louis

    2016-05-01

    A sound understanding of the various factors influencing and associated with the formation of sinkholes or subsidences on dolomite land is essential for the selection of appropriate rehabilitation methods. The investigation and rehabilitation of numerous sinkholes and subsidences located on dolomite in the East Rand of South Africa, created an opportunity to develop a broad based understanding of different karst environments, their susceptibility to sinkhole and subsidence formation and best practice rehabilitation methods. This paper is based on the guidelines developed whereby the geological model of the sinkhole or subsidence is used to recommend an appropriate rehabilitation method. Nine typical geological models with recommended rehabilitation methods are presented in this paper.

  4. Hydrogeology and simulation of groundwater flow and land-surface subsidence in the northern part of the Gulf Coast aquifer system, Texas, 1891-2009

    Science.gov (United States)

    Kasmarek, Mark C.

    2012-01-01

    In cooperation with the Harris–Galveston Subsidence District, Fort Bend Subsidence District, and Lone Star Groundwater Conservation District, the U.S. Geological Survey developed and calibrated the Houston Area Groundwater Model (HAGM), which simulates groundwater flow and land-surface subsidence in the northern part of the Gulf Coast aquifer system in Texas from predevelopment (before 1891) through 2009. Withdrawal of groundwater since development of the aquifer system has resulted in potentiometric surface (hydraulic head, or head) declines in the Gulf Coast aquifer system and land-surface subsidence (primarily in the Houston area) from depressurization and compaction of clay layers interbedded in the aquifer sediments.

  5. Inversion of synthetic aperture radar interferograms for sourcesof production-related subsidence at the Dixie Valley geothermalfield

    Energy Technology Data Exchange (ETDEWEB)

    Foxall, B.; Vasco, D.W.

    2006-07-01

    We used synthetic aperture radar interferograms to imageground subsidence that occurred over the Dixie Valley geothermal fieldduring different time intervals between 1992 and 1997. Linear elasticinversion of the subsidence that occurred between April, 1996 and March,1997 revealed that the dominant sources of deformation during this timeperiod were large changes in fluid volumes at shallow depths within thevalley fill above the reservoir. The distributions of subsidence andsubsurface volume change support a model in which reduction in pressureand volume of hot water discharging into the valley fill from localizedupflow along the Stillwater range frontal fault is caused by drawdownwithin the upflow zone resulting from geothermal production. Our resultsalso suggest that an additional source of fluid volume reduction in theshallow valley fill might be similar drawdown within piedmont faultzones. Shallow groundwater flow in the vicinity of the field appears tobe controlled on the NW by a mapped fault and to the SW by a lineament ofas yet unknown origin.

  6. Large networks of artificial radar reflectors to monitor land subsidence in natural lowlying coastal areas

    Science.gov (United States)

    Tosi, Luigi; Strozzi, Tazio; Teatini, Pietro

    2014-05-01

    Deltas, lagoons, estuaries are generally much prone to land subsidence. They are also very sensitive to land lowering due to their small elevation with respect to the mean sea level, also in view of the expected eustatic sea rise due to climate changes. Land subsidence can be presently monitored with an impressive accuracy by Persistent Scatterer Interferometry (PSI) on the large megacities that are often located on lowlying coastlands, e.g., Shanghai (China) on the Yangtze River delta, Dhaka (Bangladesh) on the Gange River delta, New Orleans (Louisiana) on the Mississippi river delta. Conversely, the land movements of the portions of these transitional coastlands where natural environments still persist are very challenging to be measured. The lack of anthropogenic structures strongly limits the use of PSI and the difficult accessibility caused by the presence of marshlands, tidal marshes, channels, and ponds yield traditional methodologies, such as levelling and GPS, both time-consuming and costly. In this contribution we present a unique experimental study aimed at using a large network of artificial radar reflectors to measure land subsidence in natural coastal areas. The test site is the 60-km long, 10-15 km wide lagoon of Venice, Italy, where previous PSI investigations revealed the lack of radar reflectors in large portions of the northern and southern lagoon basins (e.g., Teatini et al., 2011). A network of 57 trihedral corner reflectors (TCRs) were established between the end of 2006 and the beginning of 2007 and monitored by ENVISAT ASAR and TerraSAR-X acquisitions covering the time period from 2007 to 2011 (Strozzi et al., 2012). The application has provided general important insights on the possibility of controlling land subsidence using this approach. For example: (i) relatively small-size (from 0.5 to 1.0 m edge length) and cheap (few hundred euros) TCRs suffice to be clearly detectable from the radar sensors because of the low backscattering

  7. Ten Years Of Subsidence Monitoring With SAR Interferometry And Its Contribution To Risk Management In Aguascalientes, Mexico

    Science.gov (United States)

    Esquivel, Ruben; Castaneda, Laura; Taud, Hind; Lira, Jorge

    2013-12-01

    A Study involving GPS and differential SAR interferometry (DInSAR) monitoring is developed to investigate a subsidence phenomenon in Aguascalientes valley and to obtain displacement models concerned with risk management applications and geodetic purposes. DInSAR study with archived Envisat data allows accumulated displacement mapping yearly, and recent TerraSAR-X data implementation provides a more accurate estimation of displacements, which is used for developing models to correct geodetic positions. The maximum subsidence rate calculated is 15 cm/year with a decreasing rate throughout time in some areas.

  8. Using Radar Interferometry (DinSAR) to Evaluate Land Subsidence Caused by Excessive Groundwater Withdrawal in Morocco

    Science.gov (United States)

    Durham, M. C.; Milewski, A.; El Kadiri, R.

    2013-12-01

    The combination of natural, anthropogenic, and climate change impacts on the water resources of the Middle East and North Africa (MENA) region has devastated its water resources well beyond its current and projected populations. The increased exploitation of groundwater resources in the past half-century coupled with successive droughts has resulted in the acceleration of subsidence rates in the Souss and Massa basins in Morocco. We have completed a preliminary investigation of these impacts on the Souss and Massa basins (~27,000 km2) in the southwestern part of Morocco. This area is characterized by a semi-arid climate (annual precipitation 70-250 mm/year) with agriculture, tourism, and commercial fishing as the primary economic activities, all of which require availability of adequate freshwater resources. Additionally the primary groundwater aquifer (Plio-Quaternary Plain Aquifer), an unconfined aquifer formed mostly of sand and gravel, is being harvested by >20,000 wells at a rate of 650 MCM/yr., exceeding the rate of recharge by 260 MCM/year. Intense development over the past 50 years has exposed the aquifer to a serious risk of groundwater table drawdown (0.5m-2.5m/yr.), land subsidence, loss of artesian pressure, salinization, salt water intrusions along the coast, and deterioration of water quality across the watershed. Differential Interferometry Synthetique Aperture Radar (DInSAR) was utilized to measure ground subsidence induced by groundwater withdrawal. Land subsidence caused by excessive groundwater extraction was determined using a threefold methodology: (1) extraction of subsidence and land deformation patterns using radar interferometry, (2) correlation of the high subsidence areas within the basins to possible natural and anthropogenic factors (e.g. sea level rise, unconsolidated lithological formations distribution, urbanization, excessive groundwater extraction), and (3) forecasting the future of the Souss and Massa basins over the next century

  9. Evidence of Coseismic Subsidence Along the Newport-Inglewood Fault Zone During the Late Holocene

    Science.gov (United States)

    Leeper, R. J.; Rhodes, B. P.; Kirby, M. E.; Scharer, K. M.; Starratt, S.; Hemphill-Haley, E.; Bonuso, N.; Balmaki, B.; Garcia, D. J.; Creager, D. O.

    2014-12-01

    The Seal Beach wetlands (SBW) are located along strike of the Newport-Inglewood fault zone (NIFZ), where fault geometry is poorly understood. However, the fault steps to the right in the SBW, and oil well and seismological studies indicate that the northeast segment of the fault is down-dropped as a result of oblique-normal slip. The location is significant because coseismic subsidence could alter tidal and/or fluvial processes within the SBW. Such a change should be recorded in the stratigraphy by sudden changes in grain size, magnetic susceptibility, and/or diatom assemblages. Based on field observations of 48 reconnaissance gouge cores and multi-proxy analyses of three vibracores and one piston core, we identify four stratigraphic units in the SBW: (1) very fine to fine sand from 426-350 cm; (2) organic-rich mud from 350-225 cm; (3) fine to coarse silt and clay from 225-100 cm; and (4) organic-rich mud with interbedded mud laminae from 100-0 cm. We interpret unit 2 to represent a relic marsh surface that subsided coseismically and was preserved under unit 3. We analyzed 38 sediment samples for diatoms from vibracore SB002VC to test this idea and characterize the depositional environment of stratigraphic units 4, 3, and 2. The diatom data suggest unit 4 is an intertidal deposit, unit 3 is a fresh/slightly brackish water deposit, and unit 2 is an intertidal deposit. Units 2 and 3 are separated by a sharp, irregular contact. Thus, the diatom data and depositional contact from vibracore SB002VC are consistent with a relic marsh surface subsiding abruptly during an earthquake on the NIFZ. As a result of the earthquake, the intertidal environment abruptly changed to an environment dominated by fresh to slightly brackish water. We hypothesize that the earthquake did not result in flooding by seawater because coseismic uplift of the southwest segment of the NIFZ temporarily isolated the SBW from tidal influence. Radiocarbon dates constrain this event to no more than

  10. Subsidence History, Seismic Stratigraphy and Crustal Structure of Western Musandam Peninsula

    Science.gov (United States)

    Watts, A. B.; Ali, M.; Aidarbayev, S.; Searle, M. P.

    2016-12-01

    Seismic reflection profiles and deep exploratory well data have been used to determine the tectonic subsidence and uplift history of the Mesozoic rifted margin, late Cretaceous fold-thrust belt, Oligocene-Miocene culmination and foreland basins of the western margin of Musandam Peninsula. Seismic stratigraphy of regional seismic profiles show that the subsurface architecture of the western side of the Musandam Peninsula can be divided into six main sequences: (1) Late Permian-Jurassic rifted margin sequence (2) Early Cretaceous to Cenomanian shelf carbonates, (3) Late Cretaceous Aruma foreland basin sequence (4) Early-mid Cenozoic Pabdeh foreland basin sequence (5) Late Cenozoic and (6) a sequence above the Late Pliocene unconformity which marks the final continental collision expressed along the Zagros Fold Belt in Iran. In addition, the seismic profiles captured multiple west-verging and east-dipping thrust faults associated with frontal deformation of the major Hagab thrust, which causes repetition of stratigraphic layers. The majority of fault tip lines terminate within the Pabdeh Group below the mid-Miocene unconformity, which marks the timing of the end of the Musandam culmination. Backstripping of biostratigraphic data from seventeen exploration wells suggest two phases of rifting and two phases of uplift. The tectonic subsidence and uplift history at the wells can be explained by a model in which the margin developed by uniform depth extension with an initial age of rifting of 260 Ma and duration of 7 Ma and a final age of rifting of 185 Ma and a rift duration of 10 Ma. The initial rifting phase is interpreted as a result of continental breakup and opening of the Neo-Tethys Ocean, while the final rifting is attributed to final continental break-up of Gondwana and opening of the Indian Ocean. The combined effect of the two rifting events has been to thin the Arabian crust to 24-26 km. Tectonic subsidence curves indicate that the two compressional uplift

  11. Gulf Coast Subsidence: Integration of Geodesy, Geophysical Modeling, and Interferometric Synthetic Aperture Radar Observations

    Science.gov (United States)

    Blom, R. G.; Chapman, B. D.; Deese, R.; Dokka, R. K.; Fielding, E. J.; Hawkins, B.; Hensley, S.; Ivins, E. R.; Jones, C. E.; Kent, J. D.; Liu, Z.; Lohman, R.; Zheng, Y.

    2012-12-01

    The vulnerability of the US Gulf Coast has received increased attention in the years since hurricanes Katrina and Rita. Agencies responsible for the long-term protection of lives and infrastructure require precise estimates of future subsidence and sea level rise. A quantitative, geophysically based methodology can provide such estimates by incorporating geological data, geodetic measurements, geophysical models of non-elastic mechanical behavior at depth, and geographically comprehensive deformation monitoring made possible with measurements from Interferometric Synthetic Aperture Radar (InSAR). To be effective, results must be available to user agencies in a format suitable for integration within existing decision-support processes. Work to date has included analysis of historical and continuing ground-based geodetic measurements. These reveal a surprising degree of complexity, including regions that are subsiding at rates faster than those considered for hurricane protection planning of New Orleans and other coastal communities (http://www.mvn.usace.army.mil/pdf/hps_verticalsettlement.pdf) as well as Louisiana's coastal restoration strategies (http://www.coast2050.gov/2050reports.htm) (Dokka, 2011, J. Geophys. Res., 116, B06403, doi:10.1029/2010JB008008). Traditional geodetic measurements provide precise information at single points, while InSAR observations provide geographically comprehensive measurements of surface deformation at lower vertical precision. Available InSAR data sources include X-, C- and L-band satellite, and NASA/JPL airborne UAVSAR L-band data. The Gulf Coast environment is very challenging for InSAR techniques, especially with systems not designed for interferometry. For example, the shorter wavelength C-band data decorrelates over short time periods requiring more elaborate time-series analysis techniques, with which we've had some success. Meanwhile, preliminary analysis of limited L-Band ALOS/PALSAR satellite data show promise

  12. Diatoms confirm coseismic uplift and subsidence along the eastern Alaska-Aleutian megathrust

    Science.gov (United States)

    Dura, T.; Briggs, R. W.; Engelhart, S. E.; Nelson, A. R.; Horton, B.

    2013-12-01

    The Alaska-Aleutian subduction zone is the source of a series of Mw 8-9.2 20th century ruptures, including the second largest historical earthquake ever recorded in 1964. Paleoseismic studies, employing coastal stratigraphic sequences, have been successfully applied at sites within the 1964 rupture zone, but geologic records are unstudied west of the 1964 rupture. Understanding the behavior of the megathrust is important because a tsunamigenic rupture could damage the west coast of the United States. Investigations in the tidal marshes of Sitkinak Island, off the southwest coast of Kodiak Island, have uncovered stratigraphic evidence of five apparent coseismic land-level changes. Radiocarbon, 210Pb, and 137Cs dating indicate this record may include the 1964 and 1788 earthquakes and some predecessors. Here, we present new paleoecological evidence that independently confirms the inference that at least four of the abrupt lithologic changes in the stratigraphy of Sitkinak Island record coseismic land-level changes. Sudden and lasting changes in fossil diatom assemblages spanning tidal lithologic contacts reveal both coseismic subsidence (mud over peat) and coseismic uplift (peat over mud) during the last 1000 years. Across the contact that may mark the 1964 earthquake, a shift from a brackish, low-marsh diatom assemblage dominated by Diploneis interrupta and Navicula cincta to a tidal flat assemblage containing Actinocyclus normanii and Synedra tabulata indicates a sudden rise in relative sea-level, which we infer to record coseismic subsidence. In contrast, diatoms show evidence of coseismic uplift across the probable 1788 contact. An abrupt transition from a fully marine assemblage containing coastal planktonic and tychoplanktonic taxa to a freshwater marsh assemblage dominated by the salt-intolerant benthic diatom Eunotia fallax is consistent with a sudden and lasting relative sea-level fall. Abrupt changes in lithology across a contact dated about ~575 cal yr

  13. Study of the 3D displacement field in Lorca (Murcia, Spain) subsidence area

    Science.gov (United States)

    Fernandez, Jose; Prieto, Juan F.; Palano, Mimmo; Abajo, Tamara; Perez, Enrique; Escayo, Joaquin; Velasco, Jesus; Herrero, Tomas; Camacho, Antonio G.; Bru, Guadalupe; Molina, Inigo; Lopez, Juan C.; Rodriguez-Velasco, Gema; Gomez, Israel

    2017-04-01

    González and Fernández (2011) revealed that the Alto Guadalentín Basin, located in southern Spain, is affected by the highest subsidence rates measured in Europe (about 10 cm/yr) as a direct consequence of long-term aquifer exploitation. They used ERS and ENVISAT radar data spanning the 1992 - 2007 period. They identify a delayed transient nonlinear compaction of the Alto Guadalentín aquifer due to the 1990-1995 drought period. González et al. (2012) evaluated the relationship between crust unloading due to groundwater overexploitation and stress change on regional active tectonic faults in the same in relation with the May 2008 Lorca earthquake. Bonì et al. (2014) extended these previous studies using advanced DInSAR techniques and ALOS PALSAR (2007-2010) and COSMO-SkyMed (2011-2012) radar images for the time period 1992-2012. Additionally, the satellite measurements provide locally comparable results with measurements acquired by two permanent GNSS stations located in the study area. Furthermore, new geological and hydrogeological data were collected and analyzed in order to assess aquifer system compressibility and groundwater level changes in the past 50 years. The comparison of these data with advanced DInSAR displacement measurements allowed for a better spatial and temporal understanding of the governing mechanisms of subsidence due to overexploitation of the Alto Guadalentín aquifer system. But even though the aforementioned achievements have been reached, all regional studies of the area to date are based on satellite radar interferometry using just ascending or descending acquisitions, without any combination among them to obtain vertical and horizontal (E-W) components. Therefore, only the regional LOS displacement field is known and it is assumed to correspond to vertical displacement. However, it is important to obtain the 3D motion field in order to perform a correct interpretation of the observations, as well as to carry out an advanced

  14. Land Subsidence Monitoring Using PS-InSAR Technique for L-Band SAR Data

    Science.gov (United States)

    Thapa, S.; Chatterjee, R. S.; Singh, K. B.; Kumar, D.

    2016-10-01

    Differential SAR-Interferometry (D-InSAR) is one of the potential source to measure land surface motion induced due to underground coal mining. However, this technique has many limitation such as atmospheric in homogeneities, spatial de-correlation, and temporal decorrelation. Persistent Scatterer Interferometry synthetic aperture radar (PS-InSAR) belongs to a family of time series InSAR technique, which utilizes the properties of some of the stable natural and anthropogenic targets which remain coherent over long time period. In this study PS-InSAR technique has been used to monitor land subsidence over selected location of Jharia Coal field which has been correlated with the ground levelling measurement. This time series deformation observed using PS InSAR helped us to understand the nature of the ground surface deformation due to underground mining activity.

  15. INVESTIGATION OF GROUND PENETRATING RADAR FOR DETECTION OF ROAD SUBSIDENCE NORTHCOAST OF JAKARTA, INDONESIA

    Directory of Open Access Journals (Sweden)

    Kris Budiono

    2017-07-01

    Full Text Available A survey of Ground Penetrating Radar (GPR was conducted in the coastal zone of northern part of Jakarta, Indonesia. The purpose of this survey was to provide the subsurface of coastal Quaternary sedimentary features and stratigraphy disturbances associated with induce post road subsidence 2009. The possibility of subsurface lithology disturbance shown by the GPR record. This record resulted from GPR methods using SIR system 20 GSSI, 270 MHz and 400 MHz and MLF 3200 transducer. The method is a promising tool for resolving changes of physical properties in subsurface lithology condition at the natural scale due to composition changes of physical properties.The reflection data resulted that GPR can distinguish between image the basic geometry forms such as lithology , structure geology , soil and subsurface utilities condition

  16. Failure of man-made cavities in salt and surface subsidence due to sulfur mining

    Energy Technology Data Exchange (ETDEWEB)

    Coates, G.K.; Lee, C.A.; McClain, W.C.; Senseny, P.E.

    1981-01-01

    An engineering data base relevant to subsidence due to sulfur mining and to structural failure of cavities in salt is established, evaluated and documented. Nineteen failure events are discussed. Based on these documented failure events, capabilities of and inputs to a mathematical model of cavity failure are determined. Two failure events are adequately documented for use in model verification studies. A conclusion of this study that is pertinent to the Strategic Petroleum Reserve is that cavity failures in dome salt are fairly rare, but that as the number of large cavities (especially those having large roof spans) increases, failures will probably be more common unless stability and failure mechanisms of cavities are better understood.

  17. Increased Primary Production from an Exotic Invader Does Not Subsidize Native Rodents.

    Science.gov (United States)

    Lucero, Jacob E; Allen, Phil S; McMillan, Brock R

    2015-01-01

    Invasive plants have tremendous potential to enrich native food webs by subsidizing net primary productivity. Here, we explored how a potential food subsidy, seeds produced by the aggressive invader cheatgrass (Bromus tectorum), is utilized by an important guild of native consumers--granivorous small mammals--in the Great Basin Desert, USA. In a series of field experiments we examined 1) how cheatgrass invasion affects the density and biomass of seed rain at the ecosystem-level; 2) how seed resources from cheatgrass numerically affect granivorous small mammals; and 3) how the food preferences of native granivores might mediate the trophic integration of cheatgrass seeds. Relative to native productivity, cheatgrass invasion increased the density and biomass of seed rain by over 2000% (P trophic levels. In this context, cheatgrass invasion could disrupt native food webs by providing less-preferred resources that fail to enrich higher trophic levels.

  18. Organ procurement and the body donor-family binomial: instruments to subsidize nursing approach

    Directory of Open Access Journals (Sweden)

    Gisele da Cruz Ferreira

    2013-05-01

    Full Text Available We aimed to describe the design of instruments to subsidize the care for the body donor-family binomial in the perspective of the process of organ procurement. The Activities of Living Model grounded the instruments for data collection. We identified 33 possible diagnoses, 14 associated to the body preservation and 19 to responses from family members facing grieving and the decision on whether to authorize the donation. We selected 31 interventions to preserve the body for organs/tissues procurement, and 25 to meet the needs for information, coping and support for the family decision. The nursing diagnoses, interventions, and outcomes were registered according to the North American Nursing Diagnosis Association, Nursing Intervention Classification, and Nursing Outcome Classification, respectively. The instruments follow the legislation of the Board of Nursing and the donor/organ procurement, needing to be validated by field experts.

  19. [Health insurance in the contributive and subsidized regimes and its impact on the service providers].

    Science.gov (United States)

    Prada, Luis M

    2004-01-01

    The performance of 18 private Health-promoting (EPS) and Family Compensation (CCF) entities, as well as their general balances for 1997, 1998 and 1999, were studied to determine the profit margins achieved by EPS's in their work of administering health insurance. The average behavior of each EPS balance sheet was analyzed to reduce the effect produced by extreme cases; each EPS's value was thus weighted by the number of its affiliated people. The expected behavior of the costs and expenses of companies whose main business is providing health insurance could thus become determined. The main source of operational income for a private EPS is the contributive regime's per capita unit of payment (UPC). Subsidized regime participation and that of other sources of income has decreased year by year. By contrast, public EPS's have shown decreasing participation in income obtained from UPC (contributive and subsidized) and growing dependence on other sources of income; this can be interpreted as being a symptom of weak commercial management. According to the balance sheets provided by the SNS, the EPS (public, private and Family Compensation entities), including the Social Security Institute (ISS), together obtained a total of 4.18 billion pesos operational income in 1999, an increase of 21.7% as compared to 1998. Income received from the ISS amounted to 1.93 billion dollars in 1999 (46% of the total). At 2000 prices, the total amount of operational income was 4.54 billion pesos in 1999 (15.6% real increase). Taking the behavior of 4 EPS's as our reference point (Sanitas, Humana Vivir, Coomeva and Famisanar), it can be concluded that an EPS whose main business is health insurance needs a 17.2% gross margin to cover its operational and non-operational costs and a 1.1% margin before tax.

  20. Radar Interferometry for Monitoring Land Subsidence Due to Over-Pumping Ground Water in Crete, Greece

    Science.gov (United States)

    Mertikas, S. P.; Papadaki, E. S.

    2010-03-01

    The level of water in several wells at the Messara valley, Crete, Greece has dropped 40 meters over the last 20 years. Anecdotal reports describe cracks in the concrete foundations of some residential structures around the valley. These also suggest that ground subsidence may exceed one centimeter, at least, over a period of recharging and withdrawal ground water.Conventional differential SAR interferometry using ERS-SAR and ALOS-PALSAR images, as well as the stacking technique have been applied to monitor this ground deformation. The used images covered the period from 1992 to 2000 and 2007-2009, respectively.A total of 29 ERS-1&2 SAR and 7 ALOS images have been used for forming interferograms. Image pairs with Doppler difference less than 0.20 pulse repetition frequency, and perpendicular baseline smaller than 100m have been used for processing. A Digital Elevation Model with 20-m pixel size and ±7 m height accuracy has also been incorporated in interferometric processing. Atmospheric artifacts have been compensated by using image stacking.The valley to be monitored is densely cultivated and irrigated. Thus, loss of coherence in images has been observed in the C-Band and could not be overcome. Consequently, interferometric results with the ERS-SAR images have been limited. On the other hand, processing of L-band data has brought up a ground deformation that amounted to a subsidence of at least 4 cm/yr. The correlation of the observed ground deformation with respect to water pumping and other geological parameters has also been investigated.

  1. Land subsidence in southwest Cyprus revealed from C-band radar interferometry

    Science.gov (United States)

    Michalis, Pantelis; Giourou, Anthi; Charalampopoulou, Betty; Li, Zhenhong; Li, Yongsheng

    2014-08-01

    Land subsidence is a major worldwide hazard, and causes many problems including: damage to public facilities such as bridges, roads, railways, electric power lines, underground pipes; damage to private and public buildings; and in some cases of low-lying land, can increase the risk of coastal flooding from storm surges and rising sea-levels. The island of Cyprus is famous for its complex geology, particularly in the southwest part of the island. Deposits of massive breccias (melange) are widely exposed in the Paphos District situated between the Troodos Mountains and the sea. These deposits are rich in clay minerals that are prone to landslide phenomena. With its global coverage and all-weather imaging capability, Interferometric SAR (InSAR) is revolutionizing our ability to image the Earth's surface and the evolution of its shape over time. In this paper, an advanced InSAR time series technique, InSAR TS + AEM, has been employed to analysed C-band ERS and Envisat data collected over southwest Cyprus during the period from 1992 to 2010. Our InSAR time series results suggest that: (1) a total number of 274,619 coherent pixels with a density of 46 points per squared km were detected in the area of interest; and (2) clear surface displacements can be observed in several areas. The combination of archived ESA SAR datasets allows a long record (~18 years) of historic deformation to be measured over a large region. Ultimately this should help inform land managers in assessing land subsidence and planning appropriate remedial measures.

  2. Gas Evidence and Seepage: Implications and Subsidence in the Elkhorn Slough, CA

    Science.gov (United States)

    Garcia-Garcia, A.; King, N.; Sims, H.; Lopez, M.; Levey, M. D.; Shipton, G.; Watson, E. B.; Eby, R.

    2013-12-01

    The presence of gas pockets underneath the sediments of the Elkhorn Slough, a 10-km long, 1200-hectare tidal estuary located in Monterey Bay, has been imaged for the first time. Seismic surveys were run in 2011-2012 with an EdgeTech SB-424 full-spectrum sub-bottom CHIRP profiler, used with a default pulse which generates a sweep frequency of 4 kHz - 24 kHz for 10 ms, and a vertical resolution of 0.4 m. This system performed ideally in this shallow environment. Preliminary interpretation of the data shows multiple and widespread evidence of gas as acoustic blanking, acoustic turbidity, and acoustic plumes. The interpreted gas affects the sedimentary column from 5 m below the present channel all the way up to the surface. The gas front of these pockets is buried under the last two seismic units below the channel floor, and in some cases, reaches the surface of the sedimentary column. There are also indications of seepage from these pockets towards the water column, suggesting the seal is no longer effective. Multiples cores were taken between 2008 and 2011 and they confirm the presence of methane (as well as gas cracking evidence in XRays). The areas with unstable methane gas affect this delicate environment, which is currently under a watch for subsidence and strong erosion. The gas seepage can be triggering further collapse of sediments and enhancing the subsidence. In the present work we discuss these factors as well as aim to quantify how much gas the Slough sediments hold and how much is escaping at present. Acknowledgments: CSUMB (chirp), ESNEER staff for their support. The ';Dr. Douglas Garrison Fund' for Educational Excellence (MPC) and ONR supported this research. Figure 1. Chirp examples showing interpreted gas seepage (above) and gas pockets within the sediments (below).

  3. Water-gas dynamics and coastal land subsidence over Chioggia Mare field, northern Adriatic Sea

    Science.gov (United States)

    Teatini, Pietro; Baú, Domenico; Gambolati, Giuseppe

    2000-09-01

    A major development programme comprising 15 gas fields of the northern Adriatic Sea has recently been submitted to the Ministry of the Environment, VIA Committee for the assessment of the environmental impact, by ENI-Agip, the Italian national oil company. One of the largest reservoirs is Chioggia Mare, located about 10 km offshore of the Venetian littoral, with a burial depth of 1000-1400 m. The planned gas production from this field is expected to impact the shoreline stability with a potential threat to the city of Venice, 25 km northwest of the center of Chioggia Mare. To evaluate the risk of anthropogenic land subsidence due to gas withdrawal, a numerical model was developed that predicts the compaction of both the gas-bearing formations and the lateral/bottom aquifer (water drive) during a 13-year producing and a 12-year post-production period, and the transference of the deep compaction to the ground surface. To address the uncertainty of a few important hydromechanical parameters, several scenarios are simulated and the most pessimistic predictions obtained. The modeling results show that at most 1 cm of land subsidence over 25 years may be expected at the city of Chioggia, whereas Venice is not subject to settlement. If aquifer drawdown is mediated by water injection, land subsidence is arrested 5 km offshore, with the Chioggia littoral zone experiencing a rebound of 0.6-0.7 cm. Résumé. Un important programme de développement portant sur 15 gisements de gaz du nord de l'Adriatique a été récemment soumis au Comité VIA pour l'évaluation de l'impact sur l'environnement du Ministère de l'Environnement, par la société ENI-Agip, la compagnie nationale pétrolière italienne. L'un des plus importants réservoirs est celui de Chioggia Mare, situé à environ 10 km au large du littoral vénitien, à une profondeur de 1000 à 1400 m. La production de gaz prévue pour ce gisement laisse envisager un impact sur la stabilité du trait de côte, avec une

  4. Multitemporal monitoring of Karviná subsidence troughs using Sentinel-1 and TerraSAR-X interferometry

    Czech Academy of Sciences Publication Activity Database

    Lazecký, M.; Jiránková, E.; Kadlečík, Pavel

    2017-01-01

    Roč. 14, č. 1 (2017), s. 53-59 ISSN 1214-9705 Institutional support: RVO:67985891 Keywords : subsidence * SAR Interferometry * Sentinel-1 * TerraSAR-X * mining Subject RIV: DE - Earth Magnetism, Geodesy, Geography OBOR OECD: Physical geography Impact factor: 0.699, year: 2016 https://www.irsm.cas.cz/index_en.php?page=acta_detail_doi&id=187

  5. The cost of karst subsidence and sinkhole collapse in the United States compared with other natural hazards

    Science.gov (United States)

    Weary, David J.

    2015-01-01

    Rocks with potential for karst formation are found in all 50 states. Damage due to karst subsidence and sinkhole collapse is a natural hazard of national scope. Repair of damage to buildings, highways, and other infrastructure represents a significant national cost. Sparse and incomplete data show that the average cost of karst-related damages in the United States over the last 15 years is estimated to be at least $300,000,000 per year and the actual total is probably much higher. This estimate is lower than the estimated annual costs for other natural hazards; flooding, hurricanes and cyclonic storms, tornadoes, landslides, earthquakes, or wildfires, all of which average over $1 billion per year. Very few state organizations track karst subsidence and sinkhole damage mitigation costs; none occurs at the Federal level. Many states discuss the karst hazard in their State hazard mitigation plans, but seldom include detailed reports of subsidence incidents or their mitigation costs. Most State highway departments do not differentiate karst subsidence or sinkhole collapse from other road repair costs. Amassing of these data would raise the estimated annual cost considerably. Information from insurance organizations about sinkhole damage claims and payouts is also not readily available. Currently there is no agency with a mandate for developing such data. If a more realistic estimate could be made, it would illuminate the national scope of this hazard and make comparison with costs of other natural hazards more realistic.

  6. Subsidence Mechanism and Stability Assessment Methods for Partial Extraction Mines for Sustainable Development of Mining Cities—A Review

    Directory of Open Access Journals (Sweden)

    Yang Yu

    2018-01-01

    Full Text Available Partial extraction methods such as underground strip pillar mining or room-and-pillar mining are widely adopted techniques to control ground subsidence. However, pillar failure in partial extraction mines may introduce violent secondary ground collapses. The stability of partial extraction mines dictates the safety of ground surface structures and the environmental health state of the surrounding mining areas. To reuse mining subsidence lands, it is necessary to evaluate the stability of the land through mine subsidence assessments. This paper summarizes current pillar stability assessment methods and their limitations, and the rock mechanics associated with the stability of abandoned mines. The effects of multiple factors that affect mine stability are discussed in detail; special attention has been extended to discuss the weathering effects associated with infused water and spontaneous combustion, as these are some key reasons for pillar strength degradation in abandoned mines. The mechanism of mine collapse and the corresponding post-mining disasters are also summarized. Finally, suggestions and strategies to improve current mine stability assessment methods are proposed based on the perspective of subsidence control.

  7. Value Assessment of Artificial Wetland Derived from Mining Subsided Lake: A Case Study of Jiuli Lake Wetland in Xuzhou

    Directory of Open Access Journals (Sweden)

    Laijian Wang

    2017-10-01

    Full Text Available Mining subsided lakes are major obstacles for ecological restoration and resource reuse in mining regions. Transforming mining subsided lakes into artificial wetlands is an ecological restoration approach that has been attempted in China in recent years, but a value assessment of the approach still needs systematic research. This paper considers Jiuli Lake wetland, an artificial wetland derived from restoration of a mining subsided lake in plain area, as a case study. A value assessment model for the artificial wetland was established based on cost–benefit analysis by means of field monitoring, social surveys, GIS geostatistics, raster calculation methods, etc. Empirical analysis and calculations were performed on the case study region. The following conclusions were drawn: (1 after ecological restoration, ecosystem services of Jiuli Lake wetland which has become a national level wetland park yield positive values; (2 the improved environment of the Jiuli Lake wetland has a spillover effect on the price of surrounding land, resulting in land price appreciation; (3 using GIS geostatistics and raster calculation methods, the impact range, strength, and value of the spillover effect can be explicitly measured; (4 through the establishment of a value assessment model of the artificial wetland, incomes of the ecological restoration was found to be sufficient to cover the implementation costs, which provides a research foundation for economic feasibility of ecological restoration of mining subsided lakes.

  8. Sea-Level Rise and Land Subsidence: Impacts on Flood Projections for the Mekong Delta’s Largest City

    Directory of Open Access Journals (Sweden)

    Hiroshi Takagi

    2016-09-01

    Full Text Available The present paper demonstrates that inundation levels in the Mekong Delta’s largest city, Can Tho, are predominantly determined by ocean tides, sea-level rise, and land subsidence. Our analysis of inundation patterns projects that the duration of inundation at an important road in the city will continue to rise from the current total of 72 inundated days per year to 270 days by 2030 and 365 days by 2050. This is attributed to the combined influence of sea-level rise and land subsidence, which causes relative water level rises at a rate of 22.3 mm·yr−1. People in the Mekong Delta have traditionally lived with floods, and thus there is certain resilience among residents in coping with small floods. At present, daily maximum inundation depth, which is generally shallower than 10 cm on the road, seems to be still manageable; however, our analysis indicates that this will start drastically increasing in the coming decades and reach an average depth of 70 cm by 2050. Effective and well-planned actions to mitigate the effects of land subsidence and sea-level rise are urgently required, otherwise, local inhabitants will encounter an unmanageable increase in inundation depth and duration in the coming decades. This study, which considers both sea-level rise and land subsidence, suggests that inundation depth and duration are projected to rise much faster than those indicated by previous studies, which only consider sea-level rise.

  9. An integrated modelling framework to assess long-term impacts of water management strategies steering soil subsidence in peatlands

    NARCIS (Netherlands)

    van Hardeveld, H. A.; Driessen, P. P.J.; Schot, P. P.; Wassen, M. J.

    2017-01-01

    Around the world many peatlands are managed unsustainably. Drainage of the peat causes soil subsidence and a range of negative societal impacts. Integrated strategies are required to ensure more sustainable long-term settings, based on impact assessment models that simulate the interrelated dynamics

  10. Research on critical groundwater level under the threshold value of land subsidence in the typical region of Beijing

    Directory of Open Access Journals (Sweden)

    Y. Jiang

    2015-11-01

    Full Text Available Groundwater in Beijing has been excessively exploited in a long time, causing the groundwater level continued to declining and land subsidence areas expanding, which restrained the economic and social sustainable development. Long years of study show good time-space corresponding relationship between groundwater level and land subsidence. To providing scientific basis for the following land subsidence prevention and treatment, quantitative research between groundwater level and settlement is necessary. Multi-linear regression models are set up by long series factual monitoring data about layered water table and settlement in the Tianzhu monitoring station. The results show that: layered settlement is closely related to water table, water level variation and amplitude, especially the water table. Finally, according to the threshold value in the land subsidence prevention and control plan of China (45, 30, 25 mm, the minimum allowable layered water level in this region while settlement achieving the threshold value is calculated between −18.448 and −10.082 m. The results provide a reasonable and operable control target of groundwater level for rational adjustment of groundwater exploited horizon in the future.

  11. Tectonic subsidence modelling of the Polish Basin in the light of new data on crustal structure and magnitude of inversion

    Science.gov (United States)

    Stephenson, Randell A.; Narkiewicz, Marek; Dadlez, Ryszard; van Wees, Jan-Diederik; Andriessen, Paul

    2003-02-01

    The Polish Basin (PB) is one of a set of basins developed on the Paleozoic platform of western Europe in the Late Paleozoic between the Variscan Orogen and the East European Craton (EEC). Its main depocentral axis (the Mid-Polish Trough—MPT) was active during most of the basin development as a maximum subsidence zone with almost uninterrupted sedimentation. The present base of the Permian in the MPT ranges in depth from ca. 3000 to 3500 m near the Baltic coast to up to 8000 m to the southeast. The MPT lies parallel and adjacent to the edge of the EEC and appears to be related to a distinct structural zone within the crust (the Tornquist-Teisseyre Zone—TTZ). Subsidence of the MPT can be explained in terms of crustal extension/transtension and related lithosphere cooling coupled with the structural predetermination of the underlying TTZ. Tectonic subsidence analysis of the preserved and reconstructed stratigraphic record suggests the occurrence of a Late Permian-Early Triassic "rifting" phase. However, there is a deficit of geologically observable extensional features (faulting) of this age, implying an important relationship between this phase of apparent basin subsidence and earlier post-Variscan, Late Carboniferous-Early Permian tectonism. The match between crustal structure implied by basin modelling studies and available deep seismic sounding (DDS) data is not always clear. This is probably related to the heterogeneous basement, which comprises the outer zone of the Variscan belt in the southwest, EEC crust in the northeast, and a complex of Caledonian/reworked Precambrian crustal blocks in the central part of the basin. Changes to crustal architecture as a result of Alpine tectonics may also play a role. Increased tectonic subsidence rates during Oxfordian-Kimmeridgian times (Late Jurassic) correlate with intensified rifting and wrench activity within the Arctic-North Atlantic rift system and along the northern Tethyan margin. In contrast, accelerating

  12. Sensing the ups and downs of Las Vegas: InSAR reveals structural control of land subsidence and aquifer-system deformation

    Science.gov (United States)

    Amelung, F.; Galloway, D.L.; Bell, J.W.; Zebker, H.A.; Laczniak, R.J.

    1999-01-01

    Land subsidence in Las Vegas, Nevada, United States, between April 1992 and December 1997 was measured using spaceborne interferometric synthetic aperture radar. The detailed deformation maps clearly show that the spatial extent of subsidence is controlled by geologic structures (faults) and sediment composition (clay thickness). The maximum detected subsidence during the 5.75 yr period is 19 cm. Comparison with leveling data indicates that the subsidence rates declined during the past decade as a result of rising ground-water levels brought about by a net reduction in ground-water extraction. Temporal analysis also detects seasonal subsidence and uplift patterns, which provide information about the elastic and inelastic properties of the aquifer system and their spatial variability.

  13. Mapping and characterization of land subsidence in Beijing Plain caused by groundwater pumping using the Small Baseline Subset (SBAS InSAR technique

    Directory of Open Access Journals (Sweden)

    M. L. Gao

    2015-11-01

    Full Text Available InSAR time series analysis is widely used for detection and monitoring of slow surface deformation. In this paper, 15 TerraSAR-X radar images acquired in stripmap mode between 2012 and 2013 are processed for land subsidence monitoring with the Small Baseline Subset (SBAS approach in Beijing Plain in China. Mapping results produced by SBAS show that the subsidence rates in the area of Beijing Plain range from −97.5 (subsidence and to +23.8 mm yr−1 (uplift, relative to a presumably stable benchmark. The mapping result also reveals that there are the five subsidence centers formed by surface deformation spreading north to south east of the downtown. An uneven subsidence patten was detected near the Beijing Capital International Airpor, which may be related to loading of buildings and the aircraft.

  14. On the use of InSAR technology to assess land subsidence in Jakarta coastal flood plain

    Science.gov (United States)

    Koudogbo, Fifame; Duro, Javier; Garcia Robles, Javier; Arnaud, Alain; Abidin, Hasanuddin Z.

    2014-05-01

    Jakarta is the capital of Indonesia and is home to approximately 10 million people on the coast of the Java Sea. It is situated on the northern coastal alluvial plane of Java which shares boundaries with West Java Province in the south and in the east, and with Banten Province in the west. The Capital District of Jakarta (DKI) sits in the lowest lying areas of the basin. Its topography varies, with the northern part just meters above current sea level and lying on a flood plain. Subsequently, this portion of the city frequently floods. The southern part of the city is hilly. Thirteen major rivers flow through Jakarta to the Java Sea. The Ciliwung River is the most significant river and divides the city West to East. In the last three decades, urban growing of Jakarta has been very fast in sectors as industry, trade, transportation, real estate, among others. This exponential development has caused several environmental issues; land subsidence is one of them. Subsidence in Jakarta has been known since the early part of the 20th century. It is mainly due to groundwater extraction, the fast development (construction load), soil natural consolidation and tectonics. Evidence of land subsidence exists through monitoring with GPS, level surveys and InSAR investigations. InSAR states for "Interferometric Synthetic Aperture Radar". Its principle is based on comparing the distance between the satellite and the ground in consecutive satellite passes over the same area on the Earth's surface. Radar satellites images record, with very high precision, the distance travelled by the radar signal that is emitted by the satellite is registered. When this distance is compared through time, InSAR technology can provide highly accurate ground deformation measurements. ALTAMIRA INFORMATION, company specialized in ground motion monitoring, has developed GlobalSARTM, which combines several processing techniques and algorithms based on InSAR technology, to achieve ground motion

  15. Evolution of the techniques for subsidence monitoring at regional scale: the case of Emilia-Romagna region (Italy

    Directory of Open Access Journals (Sweden)

    G. Bitelli

    2015-11-01

    Full Text Available The recent decades have seen a significant evolution of the methodologies and techniques for the monitoring of subsidence on a regional scale: from the traditional levelling technique to GNSS and finally to SAR interferometry. The case study of Emilia-Romagna, Italy, is a prime example of this evolution. As known, the Emilia-Romagna plain is subject to a phenomenon of subsidence with a natural and an anthropogenic component, both of varying amounts depending on the area. The first contributes a few mm/year; the second, particularly evident in the last 60 years, is mainly correlated to excessive withdrawal of fluids from underground and reaches higher values (in the past, subsidence rates of several cm per year were observed in the Po delta and near Bologna. The geodetic monitoring of subsidence started in the 1950s by different entities, establishing and measuring levelling networks of varying size and with various characteristics, mainly located where the phenomenon was most clearly manifest. These local initiatives were not able to provide a consistent understanding of the phenomenon throughout the entire Emilia-Romagna plain. The first regional-scale monitoring of the Emilia-Romagna plain was initiated in 1999, with a large levelling network (about 3000 km and a coupled network of 60 GNSS points. In subsequent years, the monitoring approach has mainly focused on the most modern remote sensing techniques integrated with each other, with the adoption of the method DInSAR calibrated to a GNSS Continuous Operating Reference Stations (CORS database. The application of DInSAR methods resulted in subsidence maps with a greater level of detail. The paper analyzes the methodology choices made during 1999–2012, through three successive campaigns that adopted and integrated the different techniques.

  16. Statistical elaborations of PS DInSAR data applied to the analysis of the subsidence affecting the Venetian coast

    Science.gov (United States)

    Tessitore, Serena; Fiaschi, Simone; Achilli, Vladimiro; Fabris, Massimo; Floris, Mario

    2015-04-01

    Subsidence is a hazard that may have natural or anthropic origin. It can affect wide areas causing important economic losses. The area of the Venetian coast is affected by subsidence mainly due to the exploitation of its resources (gas and water). In particular, about 40% of the Italian extraction activities are on this area and here the subsidence arise in conjunction with the industrial revolution (1950-1970). An effective monitoring system is necessary for the correct management of the resources exploitation that, very often, is not supervised. To this aim, the innovative DInSAR techniques have been effectively employed as monitoring systems for the risk assessments of various instability phenomena, such as subsidence, landslides, volcanic eruptions, earthquakes, sinkholes. These techniques represent a powerful investigation tool for their high spatial and multi-temporal coverage, fast data acquisition, and overall low costs. Their results are the displacement estimates along the satellite Line of Sight (LOS), the velocity map and the displacements time series for the whole observation period. In the present work, the ERS and ENVISAT DInSAR data, achieved through the Persistent Scatterers (PS) technique, have been used to produce the iso-kinetic maps of deformation for an area of about 4300 Km2. Here, the mean velocities computed along the ERS and ENVISAT observation periods 1992-2000 and 2003-2010 have been interpolated through the Ordinary Kriging (OK) method. Simulated values and estimations of subsidence uncertainties have been analysed to advance the current understanding on the phenomenon that affects the study area. The achieved maps give information about the spatial distribution of the rates of deformation, which could be correlated with the available geological, hydrogeological and geotechnical data, as well as with the recorded damage to the structures and infrastructures. Then, local Authorities can use these maps as useful tools for the monitoring

  17. Is anthropogenic land-subsidence a possible driver of riverine flood-risk dynamics? A casa study in Ravenna, Italy.

    Science.gov (United States)

    Carisi, Francesca; Domeneghetti, Alessio; Castellarin, Attilio

    2017-04-01

    Can man-induced or man-accelerated land-subsidence modify significantly riverine flood-hazard in flood-prone areas? We address this question by investigating the possible changes in flood hazard over one of the most prominent cases of anthropogenic land-subsidence in Italy, a 77-km2 area around the city of Ravenna. The subsidence rate in the area, naturally in the order of a few mm/year, increased dramatically after World War II as a consequence of groundwater pumping and natural gas extraction, exceeding 110 mm/year and resulting in cumulative drops larger than 1.5 m in roughly 100 years. The Montone-Ronco and Fiumi Uniti rivers flow in the southern portion of the study area, which is protected from frequent flooding by levees. We simulated the inundation events associated with different potential levee-breaching configurations by using a fully two-dimensional hydrodynamic model constructed on the basis of four different floodplain geometries: the current topography and a reconstruction of ground elevations before anthropogenic land-subsidence, both neglecting man-made infrastructures, and the current and historical topographies completed with a representation of road and railway embankments and main land-reclamation channels. Our results show that flood-hazard changes due to anthropogenic land-subsidence are limited (e.g. significant changes in simulated values of water depth, h, velocity, v, and intensity, i=hṡv, are detected in roughly 1%, 2% and 8% of the flood-prone area, in this order) and overwhelmingly lower than those determined by the construction of road and railway embankments or artificial channel networks (20%, 14% and 48% of the flood-prone area, respectively).

  18. An Integrated Approach for the Assessment of the Natural and Anthropogenic Controls on Land Subsidence in the Kingdom of Saudi Arabia

    Science.gov (United States)

    Othman, A.; Sultan, M.; Ahmed, M.; Alharbi, T.; Gebremichael, E.; Emil, M.

    2015-12-01

    Recent land subsidence incidences in the Kingdom of Saudi Arabia (KSA) resulted in loss in life and property. In this study, an integrated approach is adopted to accomplish the following: (1) map the spatial distribution of areas that are witnessing land subsidence, (2) quantify the rates of land subsidence, and (3) identify the factors causing the observed subsidence. A three-fold approach is applied: (1) use of interferometric techniques to assess the spatial distribution of land subsidence and to quantify the rates of subsidence, (2) generate a GIS database to encompass all relevant data and derived products, and (3) correlate findings from the radar exercise with relevant spatial and temporal datasets (e.g., remote sensing, geology, fluid extraction rates, distribution of urban areas, etc.). Three main areas were selected: (1) central and northern parts of the KSA, (2) areas surrounding the Ghawar oil/gas field, and (3) the Harrat Lunayyir volcanic field. Applications of two-pass, three-pass, and SBAS radar interferometric techniques over central KSA revealed the following: (1) subsidence rates of up to -15 mm/yr were detected; the spatial distribution of the subsided areas that were extracted using the various interferometric techniques are similar, (2) subsided areas correlated spatially with the distribution of: (a) areas with high groundwater extraction rates as evidenced from the analysis of field and Gravity Recovery and Climate Experiment (GRACE) data, (b) agricultural plantations as evidenced from the analysis of field and temporal Landsat data, (c) urban areas (e.g., Buraydah City), (d) outcrops of carbonates and anhydrite formations (e.g., Khuff and Jilh formations), (3) subsidence could be related to more than one parameter. Similar research activities are underway in northern KSA and in areas surrounding the Ghawar oil/gas and the Harrat Lunayyir volcanic fields to assess the distribution and factors controlling land deformation in those areas.

  19. Mesozoic to Recent, regional tectonic controls on subsidence patterns in the Gulf of Mexico basin

    Science.gov (United States)

    Almatrood, M.; Mann, P.; Bugti, M. N.

    2016-12-01

    We have produced subsidence plots for 26 deep wells into the deeper-water areas of the Gulf of Mexico (GOM) in order to identify regional tectonic controls and propose tectonic phases. Our results show three sub-regions of the GOM basin that have distinctive and correlative subsidence patterns: 1) Northern GOM from offshore Texas to central Florida (9 wells) - this area is characterized by a deeply buried, Triassic-early Jurassic rift event that is not represented by our wells that penetrate only the post-rift Cretaceous to recent passive margin phase. The sole complexity in the passive margin phase of this sub-region is the acceleration of prograding clastic margins including the Mississippi fan in Miocene time; 2) Southeastern GOM in the Straits of Florida and Cuba area (5 wells) - this area shows that the Cretaceous passive margin overlying the rift phase is abruptly drowned in late Cretaceous as this part of the passive margin of North America that is flexed and partially subducted beneath the Caribbean arc as it encroaches from the southwest to eventually collide with the North American passive margin in the Paleogene; 3) Western GOM along the length of the eastern continental margin of Mexico (12 wells) - this is the most complex of the three areas in that shares the Mesozic rifting and passive margin phase but is unique with a slightly younger collisional event and foreland basin phase associated with the Laramide orogeny in Mexico extending from the KT boundary to the Oligocene. Following this orogenic event there is a re-emergence of the passive margin phase during the Neogene along locally affected by extensional and convergent deformation associated with passive margin fold belts. In summary, the GOM basin exhibits evidence for widespread rifting and passive margin formation associated with the breakup of Pangea in Mesozoic times that was locally superimposed and deformed during the late Cretaceous-Paleogene period by: 1) Caribbean subduction and

  20. Land subsidence in Tianjin for 2015 to 2016 revealed by the analysis of Sentinel-1A with SBAS-InSAR

    Science.gov (United States)

    Guo, Jiming; Hu, Jiyuan; Li, Bing; Zhou, Lv; Wang, Wei

    2017-04-01

    It has been suggested that Tianjin, China, has significant land subsidence due to excessive extraction of water. Although it is presently under control, the land subsidence around Tianjin suburbs in recent years should not be ignored. However, existing research work on land subsidence is based on traditional synthetic aperture radar satellite images in which the research time spans are mainly before 2012. An advanced time-series method, namely small baselines subset (SBAS) technique, is applied to a total of 27 Sentinel-1A images over Tianjin acquired between May 31, 2015, and May 13, 2016, to derive the subsidence magnitude and distribution of Tianjin. Furthermore, the overall and quantitative validations of SBAS-derived results are implemented. First, the overall subsidence distribution derived by SBAS is compared with the annual report of land subsidence in Tianjin 2015, which shows the same subsidence trend and distribution. Then, 44 benchmarks and 2 continuously operating reference station datasets, i.e., CH01 and XQYY, are processed to provide a specific validation of SBAS-derived results of Sentinel-1A. Finally, through investigation, an interpretation from two aspects of groundwater extraction and geological structures of the surrounding Wangqingtuo settlement funnel area is given.

  1. Stratigraphic architecture, bedload extraction, and mass balance of Holocene fluvial sediments in a tectonically subsiding basin within the Ganges-Brahmaputra River delta, Bangladesh

    Science.gov (United States)

    Sincavage, R.; Goodbred, S. L., Jr.; Pickering, J.; Wilson, C.; Paola, C.; Hossain, S.; Steckler, M. S.; Seeber, L.

    2014-12-01

    The Brahmaputra River occupied the tectonically active Sylhet Basin in eastern Bangladesh three times during the Holocene. With samples from more than 200 closely-spaced (3-5 km) boreholes, we take advantage of these discrete channel occupations and the high trapping efficiency of the subsiding basin to investigate dispersal of fluvial sediments. Experiment and theory suggest that depositional units transition from channels to lobes as transported sediment mass declines below ~30% of the total measured at the basin head. We test these ideas by reconstructing the geometry and grain size distributions of a large (30 m thick x 80 km wide) sand lobe formed during the mid-Holocene occupation (~7000-4000 years BP) of Sylhet Basin. Based on estimates of modern sediment discharge in the system, the volume of this sediment lobe is insufficient to account for the entire sediment budget. The smaller sediment volume is likely a consequence of reduced sediment discharge during a weakened monsoon. Additional sediment is likely to have also been routed out of the basin via an outlet located approximately along the modern Meghna River channel. Facies within Sylhet Basin can be characterized as stacked braidbelt sands in the proximal portion of the system, with isolated sand lenses further downstream, indicating a transition from a highly mobile braidbelt to a less mobile distributary system. The majority of bed load is extracted within a distance of ~150 km from the avulsion node, approximately coincident with the regional backwater reach of the Bengal Basin, suggesting a link between the hydraulic and "morphodynamic" backwater reaches of the system. Downstream fining is more rapid in sediments associated with the long-term occupation of Sylhet Basin, for which sediment is trapped over a relatively short distance within the sand wedge of central Sylhet Basin, than those from the early- and late-Holocene occupations, for which sediment is distributed over a longer path that follows

  2. Inverse modeling using PS-InSAR for improved calibration of hydraulic parameters and prediction of future subsidence for Las Vegas Valley, USA

    Directory of Open Access Journals (Sweden)

    T. J. Burbey

    2015-11-01

    Full Text Available Las Vegas Valley has had a long history of surface deformation due to groundwater pumping that began in the early 20th century. After nearly 80 years of pumping, PS-InSAR interferograms have revealed detailed and complex spatial patterns of subsidence in the Las Vegas Valley area that do not coincide with major pumping regions. High spatial and temporal resolution subsidence observations from InSAR and hydraulic head data were used to inversely calibrate transmissivities (T, elastic and inelastic skeletal storage coefficients (Ske and Skv of the developed-zone aquifer and conductance (CR of the basin-fill faults for the entire Las Vegas basin. The results indicate that the subsidence observations from PS-InSAR are extremely beneficial for accurately quantifying hydraulic parameters, and the model calibration results are far more accurate than when using only water-levels as observations, and just a few random subsidence observations. Future predictions of land subsidence to year 2030 were made on the basis of existing pumping patterns and rates. Simulation results suggests that subsidence will continue in northwest subsidence bowl area, which is expected to undergo an additional 11.3 cm of subsidence. Even mitigation measures that include artificial recharge and reduced pumping do not significantly reduce the compaction in the northwest subsidence bowl. This is due to the slow draining of thick confining units in the region. However, a small amount of uplift of 0.4 cm is expected in the North and Central bowl areas over the next 20 years.

  3. Effects of ownership, subsidization and teaching activities on hospital costs in Switzerland.

    Science.gov (United States)

    Farsi, Mehdi; Filippini, Massimo

    2008-03-01

    This paper explores the cost structure of Swiss hospitals, focusing on differences due to teaching activities and those related to ownership and subsidization types. A stochastic total cost frontier with a Cobb-Douglas functional form has been estimated for a panel of 148 general hospitals over the six-year period from 1998 to 2003. Inpatient cases adjusted by DRG cost weights and ambulatory revenues are considered as two separate outputs. The adopted econometric specification allows for unobserved heterogeneity across hospitals. The results suggest that teaching activities are an important cost-driving factor and hospitals that have a broader range of specialization are relatively more costly. The excess costs of university hospitals can be explained by more extensive teaching activities as well as the relative complexity of the offered medical treatments from a teaching point of view. However, even after controlling for such differences university hospitals have shown a relatively low cost-efficiency especially in the first two or three years of the sample period. The analysis does not provide any evidence of significant efficiency differences across ownership/subsidy categories.

  4. Crustal subsidence rate off Hawaii determined from 234U/238U ages of drowned coral reefs

    Science.gov (United States)

    Ludwig, K. R.; Szabo, B. J.; Moore, J.G.; Simmons, K.R.

    1991-01-01

    A series of submerged coral reefs off northwestern Hawaii was formed during (largely glacial) intervals when the rate of local sea-level rise was less than the maximum upward growth rate of the reefs. Mass-spectrometric 234U/238U ages for samples from six such reefs range from 17 to 475 ka and indicate that this part of the Hawaiian Ridge has been subsiding at a roughly uniform rate of 2.6 mm/yr for the past 475 ka. The 234U/238U ages are in general agreement with model ages of reef drowning (based on estimates of paleo-sea-level stands derived from oxygen-isotope ratios of deep-sea sediments), but there are disagreements in detail. The high attainable precision (??10 ka or better on samples younger than ~800 ka), large applicable age range, relative robustness against open-system behavior, and ease of analysis for this technique hold great promise for future applications of dating of 50-1000 ka coral. -Authors

  5. Evidence for coseismic subsidence events in a southern California coastal saltmarsh

    Science.gov (United States)

    Leeper, Robert; Rhodes, Brady; Kirby, Matthew; Scharer, Katherine; Carlin, Joseph; Hemphill-Haley, Eileen; Avnaim-Katav, Simona; MacDonald, Glen; Starratt, Scott; Aranda, Angela

    2017-03-01

    Paleoenvironmental records from a southern California coastal saltmarsh reveal evidence for repeated late Holocene coseismic subsidence events. Field analysis of sediment gouge cores established discrete lithostratigraphic units extend across the wetland. Detailed sediment analyses reveal abrupt changes in lithology, percent total organic matter, grain size, and magnetic susceptibility. Microfossil analyses indicate that predominantly freshwater deposits bury relic intertidal deposits at three distinct depths. Radiocarbon dating indicates that the three burial events occurred in the last 2000 calendar years. Two of the three events are contemporaneous with large-magnitude paleoearthquakes along the Newport-Inglewood/Rose Canyon fault system. From these data, we infer that during large magnitude earthquakes a step-over along the fault zone results in the vertical displacement of an approximately 5-km2 area that is consistent with the footprint of an estuary identified in pre-development maps. These findings provide insight on the evolution of the saltmarsh, coseismic deformation and earthquake recurrence in a wide area of southern California, and sensitive habitat already threatened by eustatic sea level rise.

  6. Subsidence of aircraft engine exhaust in the stratosphere: Implications for calculated ozone depletions

    Science.gov (United States)

    Rodriguez, J. M.; Shia, R.-L.; Ko, M. K. W.; Heisey, C. W.; Weistenstein, D. K.; Miake-Lye, R. C.; Kolb, C. E.

    1994-01-01

    The deposition altitude of nitrogen oxides and other exhaust species emitted by stratospheric aircraft is a crucial parameter in determining the impact of these emissions on stratospheric ozone. We have utilized a model for the wake of a High-Speed Civil Transport (HSCT) to estimate the enhancements in water and reductions in ozone in these wakes as a function of time. Radiative calculations indicate differential cooling rates as large as -5K/day at the beginning of the far-wake regime, mostly due to the enhanced water abundance. These cooling rates would imply a net sinking of the wakes of about 1.2 km after three days in the limit of no mixing. Calculated mid-latitude column ozone reductions due to emissions from a Mach 2.4 HSCT would then change from about -1% to -06%. However, more realistic calculations adopting moderate mixing for the wake reduce the net sinking to less than 0.2 km, making the impact of radiative subsidence negligible.

  7. InSAR data for monitoring land subsidence: time to think big

    Directory of Open Access Journals (Sweden)

    A. Ferretti

    2015-11-01

    Full Text Available Satellite interferometric synthetic aperture radar (InSAR data have proven effective and valuable in the analysis of urban subsidence phenomena based on multi-temporal radar images. Results obtained by processing data acquired by different radar sensors, have shown the potential of InSAR and highlighted the key points for an operational use of this technology, namely: (1 regular acquisition over large areas of interferometric data stacks; (2 use of advanced processing algorithms, capable of estimating and removing atmospheric disturbances; (3 access to significant processing power for a regular update of the information over large areas. In this paper, we show how the operational potential of InSAR has been realized thanks to the recent advances in InSAR processing algorithms, the advent of cloud computing and the launch of new satellite platforms, specifically designed for InSAR analyses (e.g. Sentinel-1a operated by the ESA and ALOS2 operated by JAXA. The processing of thousands of SAR scenes to cover an entire nation has been performed successfully in Italy in a project financed by the Italian Ministry of the Environment. The challenge for the future is to pass from the historical analysis of SAR scenes already acquired in digital archives to a near real-time monitoring program where up to date deformation data are routinely provided to final users and decision makers.

  8. Drifting plankton from a reservoir subsidize downstream food webs and alter community structure.

    Science.gov (United States)

    Doi, Hideyuki; Chang, Kwang-Hyeon; Ando, Takamitsu; Imai, Hiroyuki; Nakano, Shin-ichi; Kajimoto, Akio; Katano, Izumi

    2008-05-01

    Subsidy between ecosystems has been considered in many natural ecosystems, and should alter food webs and communities in human-impacted ones. We estimated how drifting plankton from a reservoir contribute to downstream food webs and showed that they alter community structures over a 10-km reach below the dam. To estimate the contribution of the drifting plankton to macroinvertebrates, we used C and N isotopes and an IsoSource mixing model. In spring and autumn, contributions of plankton to collector-filterer species were highest 0.2 km downstream of the dam, and clearly decreased from 0.2 to 10 km. At 0.2 km, the contribution of plankton to a predator stonefly was remarkably high. These results indicated that drifting plankton from a dam reservoir could subsidize downstream food webs and alter their energy base, but the importance of this subsidy decreased as distance from the reservoir increased. The general linear models indicated that the abundance of collector-filterers and predators was related positively to zooplankton density in stream water. Thus, food source alteration by drifting plankton also influenced the community structures downstream of the dam.

  9. Evidence for coseismic subsidence events in a southern California coastal saltmarsh

    Science.gov (United States)

    Leeper, Robert; Rhodes, Brady P.; Kirby, Matthew E.; Scharer, Katherine M.; Carlin, Joseph A.; Hemphill-Haley, Eileen; Avnaim-Katav, Simona; MacDonald, Glen M.; Starratt, Scott W.; Aranda, Angela

    2017-01-01

    Paleoenvironmental records from a southern California coastal saltmarsh reveal evidence for repeated late Holocene coseismic subsidence events. Field analysis of sediment gouge cores established discrete lithostratigraphic units extend across the wetland. Detailed sediment analyses reveal abrupt changes in lithology, percent total organic matter, grain size, and magnetic susceptibility. Microfossil analyses indicate that predominantly freshwater deposits bury relic intertidal deposits at three distinct depths. Radiocarbon dating indicates that the three burial events occurred in the last 2000 calendar years. Two of the three events are contemporaneous with large-magnitude paleoearthquakes along the Newport-Inglewood/Rose Canyon fault system. From these data, we infer that during large magnitude earthquakes a step-over along the fault zone results in the vertical displacement of an approximately 5-km2 area that is consistent with the footprint of an estuary identified in pre-development maps. These findings provide insight on the evolution of the saltmarsh, coseismic deformation and earthquake recurrence in a wide area of southern California, and sensitive habitat already threatened by eustatic sea level rise.

  10. Probabilistic Modeling of Landfill Subsidence Introduced by Buried Structure Collapse - 13229

    Energy Technology Data Exchange (ETDEWEB)

    Foye, Kevin; Soong, Te-Yang [CTI and Associates, Inc., 51331 W. Pontiac Trail, Wixom, MI 48393 (United States)

    2013-07-01

    The long-term reliability of land disposal facility final cover systems - and therefore the overall waste containment - depends on the distortions imposed on these systems by differential settlement/subsidence. The evaluation of differential settlement is challenging because of the heterogeneity of the waste mass and buried structure placement. Deterministic approaches to long-term final cover settlement prediction are not able to capture the spatial variability in the waste mass and sub-grade properties, especially discontinuous inclusions, which control differential settlement. An alternative is to use a probabilistic model to capture the non-uniform collapse of cover soils and buried structures and the subsequent effect of that collapse on the final cover system. Both techniques are applied to the problem of two side-by-side waste trenches with collapsible voids. The results show how this analytical technique can be used to connect a metric of final cover performance (inundation area) to the susceptibility of the sub-grade to collapse and the effective thickness of the cover soils. This approach allows designers to specify cover thickness, reinforcement, and slope to meet the demands imposed by the settlement of the underlying waste trenches. (authors)

  11. Combination of Conventional and Advanced DInSAR to Monitor Very Fast Mining Subsidence with TerraSAR-X Data: Bytom City (Poland

    Directory of Open Access Journals (Sweden)

    Maria Przyłucka

    2015-04-01

    Full Text Available In this work, the analysis of TerraSAR-X satellite images combining both conventional and advanced Differential Synthetic Aperture Radar Interferometry (DInSAR approaches has proven to be effective to detect and monitor fast evolving mining subsidence on urban areas in the Upper Silesian Coal Basin (Poland. This region accounts for almost three million inhabitants where mining subsidence has produced severe damage to urban structures and infrastructures in recent years. Conventional DInSAR approach was used to generate 28 differential interferograms between 5 July 2011 and 21 June 2012 identifying 31 subsidence troughs that account up to 245 mm of displacement in 54 days (equivalent to 1660 mm/year. SqueeSARTM processing yielded a very dense measurement point distribution, failing to detect faster displacements than 330 mm/year, which occur within the subsidence troughs detected with conventional DInSAR. Despite this limitation, this approach was useful to delimit stable areas where mining activities are not conducted and areas affected by residual subsidence surrounding the detected subsidence troughs. These residual subsidence mining areas are located approximately 1 km away from the 31 detected subsidence troughs and account for a subsidence rate greater than 17 mm/year on average. The validation of this methodology has been performed over Bytom City were underground mining activity produced severe damages in August 2011. Conventional DInSAR permitted to successfully map subsidence troughs between July and August 2011 that coincide spatially and temporally with the evolution of underground mining excavations, as well as with the demolition of 28 buildings of Karb district. Additionally, SqueeSARTM displacement estimates were useful to delimit an area of 8.3 km2 of Bytom city that is affected by a residual mining subsidence greater than 5 mm/year and could potentially suffer damages in the midterm. The comparison between geodetic data and

  12. Threshold in North Atlantic-Arctic circulation controlled by the Oligocene-Miocene subsidence of the Greenland-Scotland Ridge

    OpenAIRE

    Stärz, Michael; Jokat, Wilfried; Knorr, Gregor; Lohmann, Gerrit

    2016-01-01

    Changes in high latitude ocean gateways are thought to be main drivers of Cenozoic climate evolution. However, the link between global climate changes and the early ocean gateway formation between the North Atlantic and the Arctic Ocean (incl. the Greenland and Norwegian Seas) controlled by the subsidence of the Greenland-Scotland Ridge is poorly understood. Here, we use a coupled ocean–atmosphere general circulation model for Oligocene-Miocene boundary conditions to address the ventilation h...

  13. Has land subsidence changed the flood hazard potential? A case example from the Kujukuri Plain, Chiba Prefecture, Japan

    Directory of Open Access Journals (Sweden)

    H. L. Chen

    2015-11-01

    Full Text Available Coastal areas are subject to flood hazards because of their topographic features, social development and related human activities. The Kujukuri Plain, Chiba Prefecture, Japan, is located nearby the Tokyo metropolitan area and it faces to the Pacific Ocean. In the Kujukuri Plain, widespread occurrence of land subsidence has been caused by exploitation of groundwater, extraction of natural gas dissolved in brine, and natural consolidation of the Holocene and landfill deposits. The locations of land subsidence include areas near the coast, and it may increase the flood hazard potential. Hence, it is very important to evaluate flood hazard potential by taking into account the temporal change of land elevation caused by land subsidence, and to prepare hazard maps for protecting the surface environment and for developing an appropriate land-use plan. In this study, flood hazard assessments at three different times, i.e., 1970, 2004, and 2013 are implemented by using a flood hazard model based on Multicriteria Decision Analysis with Geographical Information System techniques. The model incorporates six factors: elevation, depression area, river system, ratio of impermeable area, detention ponds, and precipitation. Main data sources used are 10 m resolution topography data, airborne laser scanning data, leveling data, Landsat-TM data, two 1:30 000 scale river watershed maps, and precipitation data from observation stations around the study area and Radar data. The hazard assessment maps for each time are obtained by using an algorithm that combines factors with weighted linear combinations. The assignment of the weight/rank values and their analysis are realized by the application of the Analytic Hierarchy Process method. This study is a preliminary work to investigate flood hazards on the Kujukuri Plain. A flood model will be developed to simulate more detailed change of the flood hazard influenced by land subsidence.

  14. The prediction of mining induced movements in building structures and the development of improved methods of subsidence impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Arthur Waddington [Mine Subsidence Engineering Consultants Pty Ltd. (Australia)

    2009-03-15

    The major aims of this research project were to develop improved methods of assessing the likely damage to building structures and to more clearly define what constitutes a 'safe, serviceable and repairable' level of damage. It was anticipated that such methods would avoid the sterilisation of valuable coal resources. The research work was based upon measured impacts on building structures, which were recorded as longwalls were mined at Tahmoor Colliery and historical claims data provided by the Mine Subsidence Board for the Newcastle and Southern Coalfields. The research project involved - A state-of-the-art review; Collection of historical claims data from the records of the Mine Subsidence Board; Initial surveys of the ground above and around longwall panels; Initial surveys of building foundations above longwall panels; Pre-mining condition surveys and structural assessments of building structures; Recording of building movements and conditions during the mining period; Recording of ground movements during the mining period; Study and analysis of ground movements; Study and analysis of building movements; Review and statistical analysis of historical claims data; Correlation of building movements and levels of damage with NCB damage assessment curves; Development of improved methods for the prediction of building movements; Development of improved methods for the assessment of subsidence impacts; Study of available methods for the rectification of tilt; and Review of 'safe, serviceable and repairable' criteria. The final output from the research project is this detailed report on the findings of the research work, which includes new methods for the assessment of mining subsidence impacts on building structures.

  15. Subsidence in the Parícutin lava field: Causes and implications for interpretation of deformation fields at volcanoes

    Science.gov (United States)

    Chaussard, Estelle

    2016-06-01

    Assessment of volcanic hazards includes interpretation of ground deformation signal, which, at polygenetic volcanoes often results from the superposition of deformation due to pressure changes in the magmatic system and due to surficial processes such as cooling of emplaced lava. The deformation signal associated with emplaced lava is sometimes considered negligible if fields are decades old, but if the lava thickness is great, deformation may still be occurring, possibly leading to misinterpretation of the observed deformation. Here I evaluate the 2007-2011 ground motion of the 1943-1952 lava field of the Parícutin monogenetic cinder cone, Mexico. Interferometric Synthetic Aperture Radar (InSAR) time series reveal patchy subsidence restricted to the lava field and following linear rates up to 5.5 cm/year. There is a clear correlation between subsidence rates and topography suggesting a causal relationship with deposits or lava thickness. I estimate these thicknesses in the subsiding areas using pre- and post-eruption topographic maps and show that they reach up to 200 m. A numerical model for lava flow cooling was developed considering radiation and convection from the surface, conductive transfer inside the flow and to the ground, and vesiculation and latent heat generation at the top and bottom of the flow. The model shows that compaction induced by cooling of the thick deposits emplaced 60 years ago explains the observed subsidence when conductive transfer to the ground is considered. These results demonstrate that thick deposits can keep deforming significantly even decades after their emplacement, emphasizing the importance of considering cooling processes when interpreting deformation fields at polygenetic volcanoes producing massive lava fields.

  16. Rapidly progressive periodontitis. A distinct clinical condition.

    Science.gov (United States)

    Page, R C; Altman, L C; Ebersole, J L; Vandesteen, G E; Dahlberg, W H; Williams, B L; Osterberg, S K

    1983-04-01

    We report radiographic, clinical, historical, and laboratory observations on seven patients selected to illustrate the features and characteristics of rapidly progressive periodontitis, with the aim of establishing this disease as a distinct clinical entity. This form of periodontitis is seen most commonly in young adults in their twenties, but it can occur in postpubertal individuals up to approximately 35 years of age. During the active phase, the gingival tissues are extremely inflamed and there is hemorrhage, proliferation of the marginal gingiva, and exudation. Destruction is very rapid, with loss of much of the alveolar bone occurring within a few weeks or months. This phase may be accompanied by general malaise, weight loss, and depression, although these symptoms are not seen in all patients. The disease may progress, without remission, to tooth loss, or alternatively, it may subside and become quiescent with or without therapy. The quiescent phase is characterized by the presence of clinically normal gingiva that may be tightly adapted to the roots of teeth with very advanced bone loss and deep periodontal pockets. The quiescent phase may be permanent, it may persist for an indefinite period, or the disease activity may return. Most patients with rapidly progressive periodontitis have serum antibodies specific for various species of Bacteroides, Actinobacillus, or both, and manifest defects in either neutrophil or monocyte chemotaxis. Affected patients generally respond favorably to treatment by scaling and open or closed curettage, especially when accompanied by standard doses of antibiotics for conventional time periods. A small minority of patients do not respond to any treatment, including antibiotics, and the disease progresses inexorably to tooth loss even in the presence of aggressive periodontal therapy and maintenance. At the present time it is not possible to distinguish prior to treatment which individuals will respond to therapy and which will

  17. Tobacco industry price-subsidizing promotions may overcome the downward pressure of higher prices on initiation of regular smoking.

    Science.gov (United States)

    Pierce, John P; Gilmer, Todd P; Lee, Lora; Gilpin, Elizabeth A; de Beyer, Joy; Messer, Karen

    2005-10-01

    Real cigarette prices in the US increased from the early 1980s to early 1990s. Holding all else equal, adolescent initiation of regular smoking should have declined during this period. Using national population-based surveys (n = 336 343) conducted in the 1990s, we present trends (early 1960s to mid-1990s) in the initiation of regular smoking among 14-17-year-old adolescents and 18-21-year-old young adults. We also present trends in consumer-price-index-adjusted cigarette price and tobacco-industry expenditures for price-subsidizing promotions. We relate price and price-subsidizing tobacco industry expenditures to trends in initiation in the two age groups, using autoregressive integrated moving average models (ARIMA). From the model results, we conclude that price-subsidizing promotions may provide the tobacco industry with an effective way to segment the market. That is, they effectively offer lower prices to population subgroups that are more price-sensitive (e.g. young smokers not yet addicted), countering the depressing effect of general price increases on smoking. Thus, we find that the relationship of cigarette price to smoking behavior is more complex than previously described. Copyright (c) 2005 John Wiley & Sons, Ltd.

  18. The effect of hydrothermal circulation on subsidence on ocean basins : evidence from the South East Indian Ocean

    Science.gov (United States)

    Géli, L.; Francheteau, J.

    2003-04-01

    While it is generally accepted that off-axis hydrothermal circulation is responsible for the majority of the observed oceanic heat flow anomalies (e. g. for the "missing" conductive heatflow through oceanic lithosphere), the effect of water circulation on the subsidence of ocean basins at the scale of tens of millions years has not been thoroughly recognized. We present a very simple model (based on the half-space model) showing that, that in some particular circumstances, hydrothermal circulation may be held responsible for unexplained subsidence rate anomalies at the scale of ocean basins. An example is given for the poorly sedimented South-East Indian Ridge flanks of age Ma1/2 ) can be more readily explained by the observed sedimentation pattern and the subsequent pattern in hydrothermal circulation than by ad hoc variations in the mantle thermal parameters. Our model assumes that in absence of sedimentation, hydrothermal circulation convectively maintains low temperatures within the upper crust at ages as old as 20 to 30 Ma. Agreement with re-assesed subsidence estimates supports the model hypothesis.

  19. Performance of pile foundation for the civil infrastructure of high speed rail in severe ground subsidence area

    Directory of Open Access Journals (Sweden)

    H. W. Yang

    2015-11-01

    Full Text Available In this study, the performance of pile foundation is assessed for the 30 km long viaduct bridge structure seating in the ground subsidence area in the central part of Taiwan. The focus of this paper is placed on the settlement behaviour of a continuous 3-span R. C. viaduct bridge supported on piles adjacent to highway embankment. Monitoring data accumulated over the last 12 years indicate that the observed pace of the settlement of the viaduct structure in other sections matches that of the ground. However, the bridge piers adjacent to the embankment have been suffering an additional approximately 1 cm settlement every year since the completion of the embankment construction. It was believed that the piers may suffer from enormous negative skin friction owing to the surcharge from the embankment and groundwater depression. This paper first summarizes the settlement analysis results to quantify the settlement of pile due to regional ground subsidence and the combined effects from ground water fluctuation and embankment surcharge loading. Accordingly, a loading path on P'-q stress space is formulated to illustrate the loading variation subject to the combined loading effects that can explain why the combined effect becoming significant on settlement control for civil infrastructure in ground subsidence area.

  20. Performance of pile foundation for the civil infrastructure of high speed rail in severe ground subsidence area

    Science.gov (United States)

    Yang, H. W.

    2015-11-01

    In this study, the performance of pile foundation is assessed for the 30 km long viaduct bridge structure seating in the ground subsidence area in the central part of Taiwan. The focus of this paper is placed on the settlement behaviour of a continuous 3-span R. C. viaduct bridge supported on piles adjacent to highway embankment. Monitoring data accumulated over the last 12 years indicate that the observed pace of the settlement of the viaduct structure in other sections matches that of the ground. However, the bridge piers adjacent to the embankment have been suffering an additional approximately 1 cm settlement every year since the completion of the embankment construction. It was believed that the piers may suffer from enormous negative skin friction owing to the surcharge from the embankment and groundwater depression. This paper first summarizes the settlement analysis results to quantify the settlement of pile due to regional ground subsidence and the combined effects from ground water fluctuation and embankment surcharge loading. Accordingly, a loading path on P'-q stress space is formulated to illustrate the loading variation subject to the combined loading effects that can explain why the combined effect becoming significant on settlement control for civil infrastructure in ground subsidence area.

  1. Pliocene Tectonics Suggest an End to Passive Margin Subsidence: A Fresh Look at the Canterbury Basin, South Island, New Zealand

    Science.gov (United States)

    Dvorak, K.; Kominz, M. A.; Crundwell, M.

    2016-12-01

    The Canterbury Basin (South Island, New Zealand) is a passive margin that formed after initial rifting from Antarctica approximately 80 Ma (Lu and Fulthorpe, 2004). The IODP expedition 317 borehole U1352 and the nearby industry Clipper 1 cuttings have been resampled and foraminifera were analyzed to determine depositional environments from the Late Eocene to the Present (Crundwell, 2014). Using this data, a new basin subsidence model was generated for the Canterbury Basin. Backstripping reveals several tectonic `events' between about 17.5 and 11 Ma. However, the timing of these events are not consistent in the two nearby cores. This suggests that these events could be artifacts of contamination due to downslope transport of relatively shallow sediments. In contrast, both cores show an uplift event that began at about 5.5 Ma and brought this part of the South Island shelf to its current elevation by about 3 Ma. These new data suggest that, at least since 5.5 Ma, the Canterbury Basin subsidence history has not been dominated by thermally induced, passive margin subsidence. Crundwell, M.P., 2014, Pliocene to Late Eocene foraminiferal and bolboformid biostratigraphy of IODP Hole 317-U1352C, Canterbury Basin, New Zealand, GNS Science Report 2014/15, 49p. Lu, H. and Fulthorpe, C.S., 2004, Controls on sequence stratigraphy of a middle Miocene-Holocene current-swept, passive margin: Offshore Canterbury Basin, New Zealand, GSA Bulletin, v. 166, 11/12, p. 1345-1366.

  2. The effect of subsidized family planning services on reproductive behavior in the United States, 1969-1974.

    Science.gov (United States)

    Udry, J R; Bauman, K E; Morris, N M

    1976-11-01

    This paper evaluates the impact of federally subsidized family planning programs in the United States, from 1969 to 1974, on the reproductive behavior of ever-married women, 15-44 years old. The study began with an experimental design and the random assigment of areas to treatment and control but was completed as a multivariate analysis, treating program input as an interval-scaled independent variable. Using "before" and "after" area sample surveys and patient service data from operating programs, the demographic impact of the program was estimated. The impact detected was nonsignificant; according to our analysis, overall use of physician-administered contraception was not affected by the subsidized programs. The only program-induced change of activity related to reproduction that we recorded was increased use of subsidized services in study areas with high program input and increased use of private physician services where program input was low. These findings need to be interpreted with the caution usually exercised in evaluating imperfect field experiments.

  3. Inversion of Synthetic Aperture Radar Interferograms for Sources of Production-Related Subsidence at the Dixie Valley Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Foxall, W; Vasco, D

    2003-02-07

    We used synthetic aperture radar interferograms to image ground subsidence that occurred over the Dixie Valley geothermal field during different time intervals between 1992 and 1997. Linear elastic inversion of the subsidence that occurred between April, 1996 and March, 1997 revealed that the dominant sources of deformation during this time period were large changes in fluid volumes at shallow depths within the valley fill above the reservoir. The distributions of subsidence and subsurface volume change support a model in which reduction in pressure and volume of hot water discharging into the valley fill from localized upflow along the Stillwater range frontal fault is caused by drawdown within the upflow zone resulting from geothermal production. Our results also suggest that an additional source of fluid volume reduction in the shallow valley fill might be similar drawdown within piedmont fault zones. Shallow groundwater flow in the vicinity of the field appears to be controlled on the NW by a mapped fault and to the SW by a lineament of as yet unknown origin.

  4. Subtropical subsidence and surface deposition of oxidized mercury produced in the free troposphere

    Science.gov (United States)

    Shah, Viral; Jaeglé, Lyatt

    2017-07-01

    that 55 % of the spatial variation of Hg wet deposition flux observed at the Mercury Deposition Network sites is explained by the combined variation of precipitation and Hg(II) produced in the upper and middle troposphere. Our simulation points to a large role of the dry subtropical subsidence regions. Hg(II) present in these regions accounts for 74 % of Hg(II) at 500 hPa over the continental US and more than 60 % of the surface Hg(II) over high-altitude areas of the western US. Globally, it accounts for 78 % of the tropospheric Hg(II) mass and 61 % of the total Hg(II) deposition. During the Nitrogen, Oxidants, Mercury, and Aerosol Distributions, Sources, and Sinks (NOMADSS) aircraft campaign, the contribution of Hg(II) from the dry subtropical regions was found to be 75 % when measured Hg(II) exceeded 250 pg m-3. Hg(II) produced in the upper and middle troposphere subsides in the anticyclones, where the dry conditions inhibit the loss of Hg(II). Our results highlight the importance the subtropical anticyclones as the primary conduits for the production and export of Hg(II) to the global atmosphere.

  5. Detection of the Subsidence Affecting a Shopping Center in Marseilles (France) using Sar Interferometry

    Science.gov (United States)

    Feurer, D.; Le Mouelic, S.; Raucoules, D.; Carnec, C.; Nédellec, J.-L.

    2004-06-01

    Help of satellite radar interferometry for urban subsidence observation has been demonstrated for several years now. This monitoring tool is able to provide an assessment of the ground motion with a millimetric accuracy and a large spatial coverage. We present here a result of this technique applied to the monitoring of a small area : the shopping centre complex and cinema multiplex in Marseilles, France. This construction work was one of the most important construction site of this last few years in France. Inaugurated in October, 1997, the multiplex had to close 6 of its 15 cinemas five months later because of collapsing risks due to important ground movements. It has been totally closed in July, 1999. The multiplex building demolition is currently under way. Finally, this "flop" represents a cost of 30 millions euros. 14 ERS images acquired between 1992 and 2000 had been processed in order to produce a set of 105 differential interferograms. We performed a recursive correction of orbital and topographic fringes using a FFT computation and a Digital Elevation Model provided by the French National Institute (IGN). The analysis of the interferograms series has allowed to detect unambiguously a signature of few pixels corresponding to the ground movement. From this study, we observed a ground deformation during 1997 to 1998, an overall stability during late 1998 to 1999 and again a deformation during late 1999 to 2000. This study shows that, in specific cases, traditional InSAR is able to provide valuable information on very localised ground deformation. It also shows the interest of a comprehensive study of the full ERS archive of this site in order to assess the stability of the ground before, when no ground-based measurements were available, during, and after the construction works.

  6. A Lower T1 Slope as a Predictor of Subsidence in Anterior Cervical Discectomy and Fusion with Stand-Alone Cages.

    Science.gov (United States)

    Lee, Su Hun; Lee, Jun Seok; Sung, Soon Ki; Son, Dong Wuk; Lee, Sang Weon; Song, Geun Sung

    2017-09-01

    Preoperative parameters including the T1 slope (T1S) and C2-C7 sagittal vertical axis (SVA) have been recognized as predictors of kyphosis after laminoplasty, which is accompanied by posterior neck muscle damage. The importance of preoperative parameters has been under-estimated in anterior cervical discectomy and fusion (ACDF) because there is no posterior neck muscle damage. We aimed to determine whether postoperative subsidence and pseudarthrosis could be predicted according to specific parameters on preoperative plain radiographs. We retrospectively analyzed 41 consecutive patients (male: female, 22: 19; mean age, 51.15±9.25 years) who underwent ACDF with a stand-alone polyether-ether-ketone (PEEK) cage (>1 year follow-up). Parameters including SVA, T1S, segmental angle and range of motion (ROM), C2-C7 cervical angle and ROM, and segmental inter-spinous distance were measured on preoperative plain radiographs. Risk factors of subsidence and pseudarthrosis were determined using multivariate logistic regression. Fifty-five segments (27 single-segment and 14 two-segment fusions) were included. The subsidence and pseudarthrosis rates based on the number of segments were 36.4% and 29.1%, respectively. Demographic data and fusion level were unrelated to subsidence. A greater T1S was associated with a lower risk of subsidence (p=0.017, odds ratio=0.206). A cutoff value of T1S<28° significantly predicted subsidence (sensitivity: 70%, specificity: 68.6%). There were no preoperative predictors of pseudarthrosis except old age. A lower T1S (T1S<28°) could be a risk factor of subsidence following ACDF. Surgeons need to be aware of this risk factor and should consider various supportive procedures to reduce the subsidence rates for such cases.

  7. Application of InSAR and gravimetric surveys for developing construction codes in zones of land subsidence induced by groundwater extraction: case study of Aguascalientes, Mexico

    Science.gov (United States)

    Pacheco-Martínez, J.; Wdowinski, S.; Cabral-Cano, E.; Hernández-Marín, M.; Ortiz-Lozano, J. A.; Oliver-Cabrera, T.; Solano-Rojas, D.; Havazli, E.

    2015-11-01

    Interferometric Synthetic Aperture Radar (InSAR) has become a valuable tool for surface deformation monitoring, including land subsidence associated with groundwater extraction. Another useful tools for studying Earth's surface processes are geophysical methods such as Gravimetry. In this work we present the application of InSAR analysis and gravimetric surveying to generate valuable information for risk management related to land subsidence and surface faulting. Subsidence of the city of Aguascalientes, Mexico is presented as study case. Aguascalientes local governments have addressed land subsidence issues by including new requirements for new constructions projects in the State Urban Construction Code. Nevertheless, the resulting zoning proposed in the code is still subjective and not clearly defined. Our work based on gravimetric and InSAR surveys is aimed for improving the subsidence hazard zoning proposed in the State Urban Code in a more comprehensive way. The study includes a 2007-2011 ALOS InSAR time-series analysis of the Aguascalientes valley, an interpretation of the compete Bouguer gravimetric anomaly of the Aguascalientes urban area, and the application of time series and gravimetric anomaly maps for improve the subsidence hazard zoning of Aguascalientes City.

  8. Land subsidence in the Cerro Prieto Geothermal Field, 1 Baja California, Mexico, from 1994 to 2005. An integrated analysis of DInSAR, levelingand geological data.

    Energy Technology Data Exchange (ETDEWEB)

    Sarychikhina, O; Glowacka, E; Mellors, R; Vidal, F S

    2011-03-03

    Cerro Prieto is the oldest and largest Mexican geothermal field in operation and has been producing electricity since 1973. The large amount of geothermal fluids extracted to supply steam to the power plants has resulted in considerable deformation in and around the field. The deformation includes land subsidence and related ground fissuring and faulting. These phenomena have produced severe damages to infrastructure such as roads, irrigation canals and other facilities. In this paper, the technique of Differential Synthetic Aperture Radar Interferometry (DInSAR) is applied using C-band ENVISAR ASAR data acquired between 2003 and 2006 to determine the extent and amount of land subsidence in the Mexicali Valley near Cerro Prieto Geothermal Field. The DInSAR results were compared with published data from precise leveling surveys (1994- 1997 and 1997-2006) and detailed geological information in order to improve the understanding of temporal and spatial distributions of anthropogenic subsidence in the Mexicali Valley. The leveling and DInSAR data were modeled to characterize the observed deformation in terms of fluid extraction. The results confirm that the tectonic faults control the spatial extent of the observed subsidence. These faults likely act as groundwater flow barriers for aquifers and reservoirs. The shape of the subsiding area coincides with the Cerro Prieto pull-apart basin. In addition, the spatial pattern of the subsidence as well as changes in rate are highly correlated with the development of the Cerro Prieto Geothermal Field.

  9. Risk factors for subsidence in anterior cervical fusion with stand-alone polyetheretherketone (PEEK) cages: a review of 82 cases and 182 levels.

    Science.gov (United States)

    Kao, Ting-Hsien; Wu, Chen-Hao; Chou, Yu-Ching; Chen, Hsien-Te; Chen, Wen-Hsien; Tsou, Hsi-Kai

    2014-10-01

    To determine risk factors for subsidence in patients treated with anterior cervical discectomy and fusion (ACDF) and stand-alone polyetheretherketone (PEEK) cages. Records of patients with degenerative spondylosis or traumatic disc herniation resulting in radiculopathy or myelopathy between C2 and C7 who underwent ACDF with stand-alone PEEK cages were retrospectively reviewed. Cages were filled with autogenous cancellous bone harvested from iliac crest or hydroxyapatite. Subsidence was defined as a decrease of 3 mm or more of anterior or posterior disc height from that measured on the postoperative radiograph. Eighty-two patients (32 males, 50 females; 182 treatment levels) were included in the analysis. Most patients had 1-2 treatment levels (62.2 %), and 37.8 % had 3-4 treatment levels. Treatment levels were from C2-7. Of the 82 patients, cage subsidence occurred in 31 patients, and at 39 treatment levels. Multivariable analysis showed that subsidence was more likely to occur in patients with more than two treatment levels, and more likely to occur at treatment levels C5-7 than at levels C2-5. Subsidence was not associated with postoperative alignment change but associated with more disc height change (relatively oversized cage). Subsidence is associated with a greater number of treatment levels, treatment at C5-7 and relatively oversized cage use.

  10. InSAR Time-Series Analysis of Land Subsidence under Different Land Use Types in the Eastern Beijing Plain, China

    Directory of Open Access Journals (Sweden)

    Chaofan Zhou

    2017-04-01

    Full Text Available In the Beijing plain, the long-term groundwater overexploitation, exploitation, and the utilization of superficial urban space have led to land subsidence. In this study, the spatial–temporal analysis of land subsidence in Beijing was assessed by using the small baseline subset (SBAS interferometric synthetic aperture radar (InSAR technique based on 47 TerraSAR-X SAR images from 2010 to 2015. Distinct variations of the land subsidence were found in the study regions. The maximum annual land subsidence rate was 146 mm/year from 2011 to 2015. The comparison between the SBAS InSAR results and the ground leveling measurements showed that the InSAR land subsidence results achieved a precision of 2 mm. In 2013, the maximum displacement reached 132 and 138 mm/year in the Laiguangying and DongbalizhuangDajiaoting area. Our analysis showed that the serious land subsidence mainly occurred in the following land use types: water area and wetland, paddy field, upland soils, vegetable land, and peasant-inhabited land. Our results could provide a useful reference for groundwater exploitation and urban planning.

  11. Study on spatial variation of land subsidence over Minagish-Umm Gudair oil fields of Kuwait using synthetic aperture radar interferometry technique

    Science.gov (United States)

    Rao, Kota S.; Al Jassar, Hala K.; Kodiyan, Nevil J.; Daniel, Viju P.

    2016-01-01

    Land subsidence can be a major problem where there are large-scale underground activities such as oil extraction. This paper addresses the spatial variability of land subsidence over Minagish and Umm Gudair oil fields of Kuwait. Synthetic aperture radar interferometry (InSAR) with multiple reference scenes using a persistent scatterer InSAR toolchain was employed in this study. Twenty-nine scenes of advanced synthetic aperture radar data (for the period January 2005 to August 2009) were used to make 20 pairs of interferograms (with high coherence and low noise) of stable point-like reflectors. The output of this study is the land subsidence maps of Minagish and Umm Gudair oil fields with a spatial resolution of 40 m. The results indicate that there is land subsidence of 29.9 mm/year in the southern part of the oil field (Umm Gudair). This is the first detailed assessment of land subsidence in the Minagish-Umm Gudair oil fields; therefore, no ground-truth data are available to compare the subsidence results. The results were consistent, indicating their validity.

  12. Detecting and Measuring Land Subsidence in Houston-Galveston, Texas using Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System Data, 2012-2016

    Science.gov (United States)

    Reed, A.; Baker, S.

    2016-12-01

    Several cities in the Houston-Galveston (HG) region in Texas have subsided up to 13 feet over several decades due to natural and anthropogenic processes [Yu et al. 2014]. Land subsidence, a gradual sinking of the Earth's surface, is an often human-induced hazard and a major environmental problem expedited by activities such as mining, oil and gas extraction, urbanization and excessive groundwater pumping. We are able to detect and measure subsidence in HG using interferometric synthetic aperture radar (InSAR) and global positioning systems (GPS). Qu et al. [2015] used ERS, Envisat, and ALOS-1 to characterize subsidence in HG from 1995 to 2011, but a five-year gap in InSAR measurements exists due to a lack of freely available SAR data. We build upon the previous study by comparing subsidence patterns detected by Sentinel-1 data starting in July 2015. We used GMT5SAR to generate a stack of interferograms with perpendicular baselines less than 100 meters and temporal baselines less than 100 days to minimize temporal and spatial decorrelation. We applied the short baseline subset (SBAS) time series processing using GIAnT and compared our results with GPS measurements. The implications of this work will strengthen land subsidence monitoring systems in HG and broadly aid in the development of effective water resource management policies and strategies.

  13. Land subsidence and recovery in the Albuquerque Basin, New Mexico, 1993–2014

    Science.gov (United States)

    Driscoll, Jessica M.; Brandt, Justin T.

    2017-08-14

    The Albuquerque Bernalillo County Water Utility Authority (ABCWUA) drinking water supply was almost exclusively sourced from groundwater from within the Albuquerque Basin before 2008. In 2008, the San Juan-Chama Drinking Water Project (SJCDWP) provided surface-water resources to augment the groundwater supply, allowing for a reduction in groundwater pumping in the Albuquerque Basin. In 2013, the U.S. Geological Survey, in cooperation with the ABCWUA, began a study to measure and compare aquifer-system and land-surface elevation change before and after the SJCDWP in 2008. Three methods of data collection with different temporal and spatial resolutions were used for this study: (1) aquifer-system compaction data collected continuously at a single extensometer from 1994 to 2013; (2) land-surface elevation change from Global Positioning System (GPS) surveys of a network of monuments collected in 1994–95, 2005, and 2014; and (3) spatially distributed Interferometric Synthetic Aperture Radar (InSAR) satellite data from 1993 to 2010. Collection of extensometer data allows for direct and continuous measurement of aquifer-system compaction at the extensometer location. The GPS surveys of a network of monuments allow for periodic measurements of land-surface elevation change at monument locations. Interferograms are limited in time by lifespan of the satellite, orbital pattern, and data quality but allow for measurement of gridded land-surface elevation change over the study area. Each of these methods was employed to provide a better understanding of aquifer-system compaction and land-surface elevation change for the Albuquerque Basin.Results do not show large magnitudes of subsidence in the Albuquerque Basin. High temporal-resolution but low spatial-resolution data measurements of aquifer-system compaction at the Albuquerque extensometer show elastic aquifer-system response to recovering groundwater levels. Results from the GPS survey of the network of monuments show

  14. DORIS downstream service: a support to civil defence autorithies in landslides and subsidence risk management

    Science.gov (United States)

    Ciampalini, A.; Del Ventisette, C.; Moretti, S.; Manunta, M.; Calò, F.; Paglia, L.; Ardizzone, F.; Guzzetti, F.; Rossi, M.; Bellotti, F.; Colombo, D.; Strozzi, T.; Wegmuller, U.; Mora, O.; Sanches, F.

    2012-04-01

    DORIS is an advanced FP7-EU project for the design of a pre-operational advanced downstream service aimed at detecting, mapping, monitoring and forecasting surface deformations, including landslides and ground subsidence, by exploiting multiple Earth Observation (EO) and ground-based (non-EO) data technologies. Ground deformations are the result of a variety of natural and human-induced causes and triggers. These phenomena are frequent and widespread in Europe, causing extensive economic damage to private properties and public assets and their social impact is relevant. In Europe, the large number of areas affected by ground deformations, the frequency and extent of the triggering events, the extent of the impact and the magnitude of the damage, make it mandatory a multiscale, systemic approach. Further, the complexity and extent of the problem is such that it cannot be tackled (and solved) at an individual, site-specific scale, or using a single technique or methodology. The problem can be approached only through the integration of data and information taken at different scales,