WorldWideScience

Sample records for earthquake induced rock

  1. Experiment on Hydraulic Fracturing in Rock and Induced Earthquake

    Institute of Scientific and Technical Information of China (English)

    Yan Yuding; Li Yalin; Zhang Zhuan; Ouyang Lisheng; Xie Mingfu

    2005-01-01

    Experiment on rock hydraulic fracturing strength under different confining pressures was conducted on a series of test specimens with various pre-cracks prepared from 7 types of rock.Combining the data of an actual reservoir-induced earthquake with the experimental results of the contemporary tectonic stress field according to the theory of rock strength and the principle and method of rock fracture mechanics, the authors tentatively investigated the earthquakes induced by pore-water pressure in rock and obtained the initial results as follows: ( 1 ) One type of induced earthquake may occur in the case of larger tectonic stress on such weak planes that strike in similar orientation of principle tectonic compressional stress in the shallows of the rock mass; the pore-water pressure σp may generate tensile fracture on them and induce small earthquakes; (2) Two types of induced earthquake may occur in the case of larger tectonic stress, i.e., ① on such weakness planes that strike in similar orientation of principle tectonic compressioual stress, σ1, in the shallows of the rockmass, the pore-water pressure, σp, may generate tensile fracture on them and induce small earthquakes; ② When the tectonic stress approximates the shear strength of the fracture, the pore-water pressure σp may reduce the normal stress, σn, on the fracture face causing failure of the originally stable fracture,producing gliding fracture and thus inducing an earthquake. σp may also increase the fracture depth, leading to an induced earthquake with the magnitude larger than the previous potential magnitude; (3) There is a depth limit for each type of rock mass, and no induced earthquake will occur beyond this limit.

  2. Effects of earthquake induced rock shear on containment system integrity. Laboratory testing plan development

    Energy Technology Data Exchange (ETDEWEB)

    Read, Rodney S. (RSRead Consulting Inc. (Canada))

    2011-07-15

    This report describes a laboratory-scale testing program plan to address the issue of earthquake induced rock shear effects on containment system integrity. The document contains a review of relevant literature from SKB covering laboratory testing of bentonite clay buffer material, scaled analogue tests, and the development of related material models to simulate rock shear effects. The proposed testing program includes standard single component tests, new two-component constant volume tests, and new scaled analogue tests. Conceptual drawings of equipment required to undertake these tests are presented along with a schedule of tests. The information in this document is considered sufficient to engage qualified testing facilities, and to guide implementation of laboratory testing of rock shear effects. This document was completed as part of a collaborative agreement between SKB and Nuclear Waste Management Organization (NWMO) in Canada

  3. Earthquake resistant design of rock oil tanks

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, M.; Iwano, M.; Izumi, H.; Shiba, Y.; Sugihara, Y.

    1983-01-01

    In order to establish a rational procedure of the earthquake resistant design of large rock caverns, such as oil storage tanks on nuclear power plants, experimental and numerical studies were conducted. Dynamic strains during earthquakes were observed on the lining of a railway tunnel constructed in a hard rock mountain, while the seismic motion in the surrounding rock was examined precisely. The observation clarified that the lining strain of the tunnel was linearly and statically related to the rock strain and the ratio of the lining strain to the rock strain was dominated by the relative stiffness of the lining and rock. Based on the results of the earthquake observation, numerical models were proposed for the estimation of the dynamic strains of rock caverns. A good agreement between the calculated strains and the observed ones assured the adequacy of the numerical models.

  4. The physics of rock failure and earthquakes

    CERN Document Server

    Ohnaka, Mitiyasu

    2013-01-01

    Despite significant advances in the understanding of earthquake generation processes and derivation of underlying physical laws, controversy remains regarding the constitutive law for earthquake ruptures and how it should be formulated. Laboratory experiments are necessary to obtain high-resolution measurements that allow the physical nature of shear rupture processes to be deduced, and to resolve the controversy. This important book provides a deeper understanding of earthquake processes from nucleation to their dynamic propagation. Its key focus is a deductive approach based on laboratory-derived physical laws and formulae, such as a unifying constitutive law, a constitutive scaling law, and a physical model of shear rupture nucleation. Topics covered include: the fundamentals of rock failure physics, earthquake generation processes, physical scale dependence, and large-earthquake generation cycles. Designed for researchers and professionals in earthquake seismology, rock failure physics, geology and earthq...

  5. Injection-induced earthquakes.

    Science.gov (United States)

    Ellsworth, William L

    2013-07-12

    Earthquakes in unusual locations have become an important topic of discussion in both North America and Europe, owing to the concern that industrial activity could cause damaging earthquakes. It has long been understood that earthquakes can be induced by impoundment of reservoirs, surface and underground mining, withdrawal of fluids and gas from the subsurface, and injection of fluids into underground formations. Injection-induced earthquakes have, in particular, become a focus of discussion as the application of hydraulic fracturing to tight shale formations is enabling the production of oil and gas from previously unproductive formations. Earthquakes can be induced as part of the process to stimulate the production from tight shale formations, or by disposal of wastewater associated with stimulation and production. Here, I review recent seismic activity that may be associated with industrial activity, with a focus on the disposal of wastewater by injection in deep wells; assess the scientific understanding of induced earthquakes; and discuss the key scientific challenges to be met for assessing this hazard.

  6. Injection-induced earthquakes

    Science.gov (United States)

    Ellsworth, William L.

    2013-01-01

    Earthquakes in unusual locations have become an important topic of discussion in both North America and Europe, owing to the concern that industrial activity could cause damaging earthquakes. It has long been understood that earthquakes can be induced by impoundment of reservoirs, surface and underground mining, withdrawal of fluids and gas from the subsurface, and injection of fluids into underground formations. Injection-induced earthquakes have, in particular, become a focus of discussion as the application of hydraulic fracturing to tight shale formations is enabling the production of oil and gas from previously unproductive formations. Earthquakes can be induced as part of the process to stimulate the production from tight shale formations, or by disposal of wastewater associated with stimulation and production. Here, I review recent seismic activity that may be associated with industrial activity, with a focus on the disposal of wastewater by injection in deep wells; assess the scientific understanding of induced earthquakes; and discuss the key scientific challenges to be met for assessing this hazard.

  7. Maximum magnitude earthquakes induced by fluid injection

    Science.gov (United States)

    McGarr, Arthur F.

    2014-01-01

    Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.

  8. Maximum magnitude earthquakes induced by fluid injection

    Science.gov (United States)

    McGarr, A.

    2014-02-01

    Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.

  9. Inside a Crustal Earthquake - the Rock Evidence

    Science.gov (United States)

    Sibson, R. H.

    2012-12-01

    Exhumed fault rock assemblages provide insights into fault zone structure, rupture processes and physical conditions of seismogenesis which can be melded with high-resolution geophysical information on modern earthquakes. The transition from dominantly cataclasite-series to mylonite-series fault rocks at greenschist and greater grades of metamorphism is the basis of fault zone models and rheological strength profiles defining the FR-VS (frictional-viscous) transition which governs the base of the microseismically defined seismogenic zone, within which larger ruptures are mostly contained. In areas of crust deforming under moderate-to-high heat flow (e.g. Japan, California) there is good correlation between geothermal gradient and the base of microseismic activity in the crust. However, compositional variations (e.g. quartz- vs. feldspar-dominant rheology) plus other factors such as water content locally perturb the base of the seismogenic zone, creating strength asperities which may affect the nucleation of large ruptures (e.g.1989 M6.9 Loma Prieta earthquake). The level of shear stress driving rupturing within the seismogenic zone remains problematic. While some estimates (e.g. those inferred from pseudotachylyte friction-melts) are broadly consistent with expectations for the frictional strength of optimally oriented faults with 'Byerlee friction' (τ ~ 80-240 MPa at 10 km depth, depending on faulting mode), others (e.g. faults with associated hydrothermal extension veins) appear to slip at much lower levels of shear stress (max. τ 90% of global seismic moment release) and areas of active compressional inversion (e.g. NE Honshu). However, while fault overpressuring is more easily generated and sustained in compressional regimes, it may be more widespread than once thought. The presence of incrementally deposited hydrothermal veins along fault slip surfaces (often associated with subsidiary extension vein arrays) is not uncommon in fault assemblages exhumed from

  10. Volcanotectonic earthquakes induced by propagating dikes

    Science.gov (United States)

    Gudmundsson, Agust

    2016-04-01

    Volcanotectonic earthquakes are of high frequency and mostly generated by slip on faults. During chamber expansion/contraction earthquakes are distribution in the chamber roof. Following magma-chamber rupture and dike injection, however, earthquakes tend to concentrate around the dike and follow its propagation path, resulting in an earthquake swarm characterised by a number of earthquakes of similar magnitudes. I distinguish between two basic processes by which propagating dikes induce earthquakes. One is due to stress concentration in the process zone at the tip of the dike, the other relates to stresses induced in the walls and surrounding rocks on either side of the dike. As to the first process, some earthquakes generated at the dike tip are related to pure extension fracturing as the tip advances and the dike-path forms. Formation of pure extension fractures normally induces non-double couple earthquakes. There is also shear fracturing in the process zone, however, particularly normal faulting, which produces double-couple earthquakes. The second process relates primarily to slip on existing fractures in the host rock induced by the driving pressure of the propagating dike. Such pressures easily reach 5-20 MPa and induce compressive and shear stresses in the adjacent host rock, which already contains numerous fractures (mainly joints) of different attitudes. In piles of lava flows or sedimentary beds the original joints are primarily vertical and horizontal. Similarly, the contacts between the layers/beds are originally horizontal. As the layers/beds become buried, the joints and contacts become gradually tilted so that the joints and contacts become oblique to the horizontal compressive stress induced by a driving pressure of the (vertical) dike. Also, most of the hexagonal (or pentagonal) columnar joints in the lava flows are, from the beginning, oblique to an intrusive sheet of any attitude. Consequently, the joints and contacts function as potential shear

  11. Fault-rock Magnetism from Wenchuan earthquake Fault Scientific Drilling project (WFSD) Implies the Different Slip Dynamics

    Science.gov (United States)

    Liu, D.; Li, H.; Lee, T. Q.; Sun, Z.

    2015-12-01

    The 2008 Mw 7.9 Wenchuan Earthquake had caused great human and financial loss, and it had induced two major earthquake surface rupture zones, including the Yingxiu-Beichuan earthquake fault (Y-B F.) and Guanxian-Anxian earthquake fault (G-A F.) earthquake surface rupture zones. After main shock, the Wenchuan earthquake Fault Scientific Drilling project (WFSD) was co-organized by the Ministry of Science and Technology, Ministry of Land and Resources and China Bureau of Seismology, and this project focused on earthquake fault mechanics, earthquake slip process, fault physical and chemical characteristics, mechanical behavior, fluid behavior, fracture energy, and so on. Fault-rocks magnetism is an effective method for the earthquake fault research, such as earthquake slip dynamics. In this study, the fault-rocks from the drilling-hole cores and close to the Wenchuan Earthquake surface rupture zone were used to do the rock-magnetism and discuss the earthquake slip dynamics. The measurement results of magnetic susceptibility (MS) show that the relative high or low MS values are corresponded to the fault-rocks from the Y-B F. and G-A F., respectively. Other rock-magnetism gives more evidence to the magnetic mineral assemblage of fault-rocks from the two earthquake fault zones. The relative high MS in the drilling-holes and trench along the Y-B F. was caused by the new-formed ferrimagnetic minerals during the high temperature and rapid speed earthquake slip process, such as magnetite and hematite, so the Y-B F. had experienced high temperature and rapid speed thermal pressurization earthquake slip mechanism. The relative low MS in the trench along the G-A F. was possible caused by high content of Fe-sulfides, and the G-A F. had possibly experienced the low temperature and slow speed mechanical lubrication earthquake slip mechanism. The different earthquake slip mechanism was possibly controlled by the deep structure of the two earthquake faults, such as the fault

  12. Analysis of Tsunamigenic Coastal Rock Slope Failures Triggered by the 2007 Earthquake in the Chilean Fjordland

    Science.gov (United States)

    Sepulveda, S. A.; Serey, A.; Hermanns, R. L.; Redfield, T. F.; Oppikofer, T.; Duhart, P.

    2011-12-01

    The fjordland of the Chilean Patagonia is subject to active tectonics, with large magnitude subduction earthquakes, such as the M 9.5 1960 earthquake, and shallow crustal earthquakes along the regional Liquiñe-Ofqui Fault Zone (LOFZ). One of the latter (M 6.2) struck the Aysen Fjord region (45.5 S) on the 21st of April 2007, triggering dozens of landslides in the epicentral area along the fjord coast and surroundings. The largest rock slides and rock avalanches induced a local tsunami that together with debris flows caused ten fatalities and severely damaged several salmon farms, the most important economic activity of the area. Multi-scale studies of the landslides triggered during the Aysen earthquake have been carried out, including landslide mapping and classification, slope stability back-analyses and structural and geomorphological mapping of the largest failures from field surveys and high-resolution digital surface models created from terrestrial laser scanning. The failures included rock slides, rock avalanches, rock-soil slides, soil slides and debris flows. The largest rock avalanche had a volume of over 20 million cubic metres. The landslides affected steep slopes of intrusive rocks of the North Patagonian batholith covered by a thin layer of volcanic soils, which supports a high forest. The results of geotechnical analyses suggest a site effect due to topographic amplification on the generation of the landslides, with peak ground accelerations that may have reached between about 1.0 and 2.0 g for rock avalanches and between 0.6 and 1.0 g for shallow rock-soil slides, depending on the amount of assumed vertical acceleration and the applied method (limit equilibrium and Newmark). Attenuation relationships for shallow crustal seismicity indicate accelerations below 0.5 g for earthquakes of a similar magnitude and epicentral distances. Detailed field structural analyses of the largest rock avalanche in Punta Cola indicate a key role in the failure

  13. Fragmentation of wall rock garnets during deep crustal earthquakes

    Science.gov (United States)

    Austrheim, Håkon; Dunkel, Kristina G.; Plümper, Oliver; Ildefonse, Benoit; Liu, Yang; Jamtveit, Bjørn

    2017-01-01

    Fractures and faults riddle the Earth’s crust on all scales, and the deformation associated with them is presumed to have had significant effects on its petrological and structural evolution. However, despite the abundance of directly observable earthquake activity, unequivocal evidence for seismic slip rates along ancient faults is rare and usually related to frictional melting and the formation of pseudotachylites. We report novel microstructures from garnet crystals in the immediate vicinity of seismic slip planes that transected lower crustal granulites during intermediate-depth earthquakes in the Bergen Arcs area, western Norway, some 420 million years ago. Seismic loading caused massive dislocation formations and fragmentation of wall rock garnets. Microfracturing and the injection of sulfide melts occurred during an early stage of loading. Subsequent dilation caused pervasive transport of fluids into the garnets along a network of microfractures, dislocations, and subgrain and grain boundaries, leading to the growth of abundant mineral inclusions inside the fragmented garnets. Recrystallization by grain boundary migration closed most of the pores and fractures generated by the seismic event. This wall rock alteration represents the initial stages of an earthquake-triggered metamorphic transformation process that ultimately led to reworking of the lower crust on a regional scale.

  14. Research of prediction for mine earthquake basing on underground rock's movement and deformation mechanism

    Institute of Scientific and Technical Information of China (English)

    LI Yong-jing

    2008-01-01

    Movement and deformation of underground rock include vertical dislocation and horizontal deformation, and the energy released by mine earthquake can be calculated basing on deformation energy. So put forwards the prediction for degree and spread of mine earthquake according to the underground rock's movement and deformation. The actual number of times and spread of mine earthquake on site were greatly identical to the prediction. The practice proves the possibility of prediction for mine earthquake basing on the analysis of underground rock's movement and deformation, and sets up new approach of mine earthquake prediction.

  15. Research of prediction for mine earthquake basing on underground rock's movement and deformation mechanism

    Institute of Scientific and Technical Information of China (English)

    LI Yong-jing

    2008-01-01

    Movement and deformation of underground rock include vertical dislocation and horizontal deformation,and the energy released by mine earthquake can be calculated basing on deformation energy.So put forwards the prediction for degree and spread of mine earthquake according to the underground rock's movement and deformation.The actual number of times and spread of mine earthquake on site were greatly identical to the prediction.The practice proves the possibility of prediction for mine earthquake basing on the analysis of underground rock's movement and deformation,and sets up new approach of mine earthquake prediction.

  16. Global review of human-induced earthquakes.

    OpenAIRE

    Foulger, Gillian R.; Wilson, Miles; Gluyas, Jon; Julian, Bruce R.; Davies, Richard

    2017-01-01

    The Human-induced Earthquake Database, HiQuake, is a comprehensive record of earthquake sequences postulated to be induced by anthropogenic activity. It contains over 700 cases spanning the period 1868–2016. Activities that have been proposed to induce earthquakes include the impoundment of water reservoirs, erecting tall buildings, coastal engineering, quarrying, extraction of groundwater, coal, minerals, gas, oil and geothermal fluids, excavation of tunnels, and adding material to the subsu...

  17. EARTHQUAKE-INDUCED DEFORMATION STRUCTURES AND RELATED TO EARTHQUAKE MAGNITUDES

    Directory of Open Access Journals (Sweden)

    Savaş TOPAL

    2003-02-01

    Full Text Available Earthquake-induced deformation structures which are called seismites may helpful to clasify the paleoseismic history of a location and to estimate the magnitudes of the potention earthquakes in the future. In this paper, seismites were investigated according to the types formed in deep and shallow lake sediments. Seismites are observed forms of sand dikes, introduced and fractured gravels and pillow structures in shallow lakes and pseudonodules, mushroom-like silts protruding laminites, mixed layers, disturbed varved lamination and loop bedding in deep lake sediments. Earthquake-induced deformation structures, by benefiting from previous studies, were ordered according to their formations and earthquake magnitudes. In this order, the lowest eartquake's record is loop bedding and the highest one is introduced and fractured gravels in lacustrine deposits.

  18. Back analysis of earthquake-induced permanent deformation parameters of earth-rock dams%土石坝地震永久变形参数反演方法研究

    Institute of Scientific and Technical Information of China (English)

    汪旭; 康飞; 李俊杰

    2014-01-01

    提出了一种基于径向基网络的土石坝永久变形参数反演分析模型。该模型充分利用了径向基神经网络的非线性映射能力,只需要进行少量的样本设计,即可反演坝体永久变形参数,可以解决土石坝动力参数反演计算耗时长的问题。同时在对永久变形参数进行灵敏度分析的基础上,建立考虑参数灵敏度的网络训练目标函数,进一步提高了反演精度。将所建立的模型用于紫平铺面板堆石坝地震永久变形参数反演,采用三维有限元法进行静动力分析,并采用改进的沈珠江模型计算坝体地震永久变形。结果表明,反演参数计算的大坝地震永久变形和坝体实测永久变形数值接近,趋势一致,因而所建立的模型能够有效地反演坝体地震永久变形参数,为土石坝的动力参数反演提供了一种简便、有效的方法。%A back analysis model based on radial basis function networks is proposed for permanent deformation parameters of earth-rock dams. The model makes good use of the nonlinear mapping capability of the radial basis function networks. It can back-analyze the permanent deformation parameters of earth-rock dams with just a small amount of sample designs, and long computational time for inversion is not needed. Meanwhile, based on the sensitivity analysis of permanent deformation parameters, an objective function for network training is established by considering parameter sensitivity, which improves the inversion accuracy further. The model is illustrated on Zipingpu concrete-faced rockfill dam (CFRD). Three-dimensional finite element method is adopted for static and dynamic analysis, and the earthquake-induced permanent deformation is calculated with improved Shen Zhujiang model. The results show that the earthquake-induced permanent deformations calculated by inversion parameters are very close to the actual values. The proposed model is efficient in back

  19. Study on probability of earthquake-induced slip of geoengineering rock mass joint plane%一地震诱发工程岩体结构面滑移概率分析

    Institute of Scientific and Technical Information of China (English)

    邓学晶; 亓玉成; 林倩; 邹德高

    2014-01-01

    Based on non-stationary random vibration model, a series of ground motions were synthesized, whose statistical parameters could satisfy the randomness of a potential earthquake. In order to evaluate the stability of engineering rock mass, horizontal equivalent acceleration (HEA) of the rock mass joint plane was defined, while the earthquake response of engi-neering rock mass was calculated numerically. The maximum horizontal equivalent acceleration (MHEA) was compared with the yield acceleration of the rock mass joint plane. Based on non-linear numerical calculations and ground motion samples of an earthquake, a new approach was proposed to calculate the probability density of the MHEA of rock mass joint plane. The application of this method in seismic reliability analysis of engineering rock mass was demonstrated. The numerical computa-tion results indicate that the probability of rock mass instability under remote earthquake is below 0. 01% , while the value is up to 26. 1% under near earthquake, given the same magnitude of earthquake.%基于非平稳随机地震动模型,编制快速合成人工地震动的程序以实现对工程地震动的随机抽样。对工程岩体地震响应进行等效线性数值计算时,定义结构面的水平等效加速度(时程),将结构面水平等效加速度(时程)的最大值超过其屈服加速度(滑移阈值)作为岩体失稳的极限条件;基于地震动随机抽样和等效线性化时程计算,提出一种随机地震动作用下工程岩体沿结构面的滑移概率和稳定可靠度的计算方法。考察某工程岩体在附近3个潜在震源影响下的结构面的滑移概率和稳定可靠性。结果表明,震级相差不大时,远场地震诱发该工程岩体的失效概率小于0.01%;近场地震作用下,工程岩体的失效概率为26.1%。

  20. Nucleation speed limit on remote fluid-induced earthquakes

    Science.gov (United States)

    Parsons, Tom; Malagnini, Luca; Akinci, Aybige

    2017-01-01

    Earthquakes triggered by other remote seismic events are explained as a response to long-traveling seismic waves that temporarily stress the crust. However, delays of hours or days after seismic waves pass through are reported by several studies, which are difficult to reconcile with the transient stresses imparted by seismic waves. We show that these delays are proportional to magnitude and that nucleation times are best fit to a fluid diffusion process if the governing rupture process involves unlocking a magnitude-dependent critical nucleation zone. It is well established that distant earthquakes can strongly affect the pressure and distribution of crustal pore fluids. Earth’s crust contains hydraulically isolated, pressurized compartments in which fluids are contained within low-permeability walls. We know that strong shaking induced by seismic waves from large earthquakes can change the permeability of rocks. Thus, the boundary of a pressurized compartment may see its permeability rise. Previously confined, overpressurized pore fluids may then diffuse away, infiltrate faults, decrease their strength, and induce earthquakes. Magnitude-dependent delays and critical nucleation zone conclusions can also be applied to human-induced earthquakes. PMID:28845448

  1. Nucleation speed limit on remote fluid induced earthquakes

    Science.gov (United States)

    Parsons, Thomas E.; Akinci, Aybige; Malignini, Luca

    2017-01-01

    Earthquakes triggered by other remote seismic events are explained as a response to long-traveling seismic waves that temporarily stress the crust. However, delays of hours or days after seismic waves pass through are reported by several studies, which are difficult to reconcile with the transient stresses imparted by seismic waves. We show that these delays are proportional to magnitude and that nucleation times are best fit to a fluid diffusion process if the governing rupture process involves unlocking a magnitude-dependent critical nucleation zone. It is well established that distant earthquakes can strongly affect the pressure and distribution of crustal pore fluids. Earth’s crust contains hydraulically isolated, pressurized compartments in which fluids are contained within low-permeability walls. We know that strong shaking induced by seismic waves from large earthquakes can change the permeability of rocks. Thus, the boundary of a pressurized compartment may see its permeability rise. Previously confined, overpressurized pore fluids may then diffuse away, infiltrate faults, decrease their strength, and induce earthquakes. Magnitude-dependent delays and critical nucleation zone conclusions can also be applied to human-induced earthquakes.

  2. DYFI data for Induced Earthquake Studies

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The significant rise in seismicity rates in Oklahoma and Kansas (OK–KS) in the last decade has led to an increased interest in studying induced earthquakes. Although...

  3. Fossil rocks of slow earthquake detected by thermal diffusion length

    Science.gov (United States)

    Hashimoto, Yoshitaka; Morita, Kiyohiko; Okubo, Makoto; Hamada, Yohei; Lin, Weiren; Hirose, Takehiro; Kitamura, Manami

    2016-04-01

    Fault motion has been estimated by diffusion pattern of frictional heating recorded in geology (e.g., Fulton et al., 2012). The same record in deeper subduction plate interface can be observed from micro-faults in an exhumed accretionary complex. In this study, we focused on a micro-fault within the Cretaceous Shimanto Belt, SW Japan to estimate fault motion from the frictional heating diffusion pattern. A carbonaceous material concentrated layer (CMCL) with ~2m of thickness is observed in study area. Some micro-faults cut the CMCL. Thickness of a fault is about 3.7mm. Injection veins and dilatant fractures were observed in thin sections, suggesting that the high fluid pressure was existed. Samples with 10cm long were collected to measure distribution of vitrinite reflectance (Ro) as a function of distance from the center of micro-fault. Ro of host rock was ~1.0%. Diffusion pattern was detected decreasing in Ro from ~1.2%-~1.1%. Characteristic diffusion distance is ~4-~9cm. We conducted grid search to find the optimal frictional heat generation per unit area per second (Q (J/m^2/s), the product of friction coefficient, normal stress and slip velocity) and slip duration (t(s)) to fit the diffusion pattern. Thermal diffusivity (0.98*10^8m^2/s) and thermal conductivity (2.0 w/mK) were measured. In the result, 2000-2500J/m^2/s of Q and 63000-126000s of t were estimated. Moment magnitudes (M0) of slow earthquakes (slow EQs) follow a scaling law with slip duration and its dimension is different from that for normal earthquakes (normal EQ) (Ide et al., 2007). The slip duration estimated in this study (~10^4-~10^5s) consistent with 4-5 of M0, never fit to the scaling law for normal EQ. Heat generation can be inverted from 4-5 of M0, corresponding with ~10^8-~10^11J, which is consistent with rupture area of 10^5-10^8m2 in this study. The comparisons in heat generation and slip duration between geological measurements and geophysical remote observations give us the

  4. Response of Alum Rock springs to the October 30, 2007 Alum Rock earthquake and implications for the origin of increased discharge after earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, Joel C [Los Alamos National Laboratory; Manga, Michael [UC BERKELEY

    2009-01-01

    The origin of increased stream flow and spring discharge following earthquakes have been the subject of controversy, in large part because there are many models to explain observations and few measurements suitable for distinguishing between hypotheses. On October 30, 2007 a magnitude 5.5 earthquake occurred near the Alum Rock springs, California, USA. Within a day we documented a several-fold increase in discharge. Over the following year, we have monitored a gradual return towards pre-earthquake properties, but for the largest springs there appears to be a permanent increase in the steady discharge at all the springs. The Alum Rock springs discharge waters that represent a mixture between modern ('shallow') meteoric water and old ('deep') connate waters expelled by regional transpression. After the earthquake, the increased discharge at the largest springs was accompanied by a small decrease in the fraction of connate water in the spring discharge. Combined with the rapid response, this implies that the increased discharge has a shallow origin. Increased discharge at these springs occurs for earthquakes that cause static volumetric expansion and those that cause contraction, supporting models in which dynamic strains are responsible for the subsurface changes that cause flow to increase. We show that models in which the permeability of the fracture system feeding the springs increases after the earthquake are in general consistent with the changes in discharge. The response of these springs to another earthquake will provide critical constraints on the changes that occur in the subsurface.

  5. Coping with earthquakes induced by fluid injection

    Science.gov (United States)

    McGarr, Arthur F.; Bekins, Barbara; Burkardt, Nina; Dewey, James W.; Earle, Paul S.; Ellsworth, William L.; Ge, Shemin; Hickman, Stephen H.; Holland, Austin F.; Majer, Ernest; Rubinstein, Justin L.; Sheehan, Anne

    2015-01-01

    Large areas of the United States long considered geologically stable with little or no detected seismicity have recently become seismically active. The increase in earthquake activity began in the mid-continent starting in 2001 (1) and has continued to rise. In 2014, the rate of occurrence of earthquakes with magnitudes (M) of 3 and greater in Oklahoma exceeded that in California (see the figure). This elevated activity includes larger earthquakes, several with M > 5, that have caused significant damage (2, 3). To a large extent, the increasing rate of earthquakes in the mid-continent is due to fluid-injection activities used in modern energy production (1, 4, 5). We explore potential avenues for mitigating effects of induced seismicity. Although the United States is our focus here, Canada, China, the UK, and others confront similar problems associated with oil and gas production, whereas quakes induced by geothermal activities affect Switzerland, Germany, and others.

  6. Earthquake faulting in subduction zones: insights from fault rocks in accretionary prisms

    Science.gov (United States)

    Ujiie, Kohtaro; Kimura, Gaku

    2014-12-01

    Subduction earthquakes on plate-boundary megathrusts accommodate most of the global seismic moment release, frequently resulting in devastating damage by ground shaking and tsunamis. As many earthquakes occur in deep-sea regions, the dynamics of earthquake faulting in subduction zones is poorly understood. However, the Integrated Ocean Drilling Program (IODP) Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) and fault rock studies in accretionary prisms exhumed from source depths of subduction earthquakes have greatly improved our understanding of earthquake faulting in subduction zones. Here, we review key advances that have been made over the last decade in the studies of fault rocks and in laboratory experiments using fault zone materials, with a particular focus on the Nankai Trough subduction zone and its on-land analog, the Shimanto accretionary complex in Japan. New insights into earthquake faulting in subduction zones are summarized in terms of the following: (1) the occurrence of seismic slip along velocity-strengthening materials both at shallow and deep depths; (2) dynamic weakening of faults by melt lubrication and fluidization, and possible factors controlling coseismic deformation mechanisms; (3) fluid-rock interactions and mineralogical and geochemical changes during earthquakes; and (4) geological and experimental aspects of slow earthquakes.

  7. Evolution of induced earthquakes from dimensionless scaling

    CERN Document Server

    van Putten, Maurice H P M; van Putten, Michel J A M

    2014-01-01

    Event counts are a powerful diagnostic for earthquake analysis. We report on a bimodal distribution of earthquake event counts in the U.S. since 2013. The new peak is about a magnitude M1 with a distribution very similar to that of induced earthquakes in Groningen, The Netherlands, characterized by exponential growth in event count since 2001. The latter shows a doubling time of 6.24 years with a relatively constant rate of land subsidence. We model its internal shear stresses as a function of dimensionless curvature and illustrate the resulting exponential growth in a tabletop crack formation experiment. Our study proposes a new method of parameter-free statistical forecasting of induced events, that circumvents the need for a magnitude cut-off in the Gutenberg-Richter relationship.

  8. Fluid Induced Earthquakes: From KTB Experiments to Natural Seismicity Swarms.

    Science.gov (United States)

    Shapiro, S. A.

    2006-12-01

    Experiments with borehole fluid injections are typical for exploration and development of hydrocarbon or geothermal reservoirs (e.g., fluid-injection experiments at Soultz, France and at Fenton-Hill, USA). Microseismicity occurring during such operations has a large potential for understanding physics of the seismogenic process as well as for obtaining detailed information about reservoirs at locations as far as several kilometers from boreholes. The phenomenon of microseismicity triggering by borehole fluid injections is related to the process of the Frenkel-Biot slow wave propagation. In the low-frequency range (hours or days of fluid injection duration) this process reduces to the pore pressure diffusion. Fluid induced seismicity typically shows several diffusion indicating features, which are directly related to the rate of spatial grow, to the geometry of clouds of micro earthquake hypocentres and to their spatial density. Several fluid injection experiments were conducted at the German Continental Deep Drilling Site (KTB) in 1994, 2000 and 2003-2005. Microseismicity occurred at different depth intervals. We analyze this microseismicity in terms of its diffusion-related features. Its relation to the 3-D distribution of the seismic reflectivity has important rock physical and tectonic implications. Starting from such diffusion-typical signatures of man-made earthquakes, we seek analogous patterns for the earthquakes in Vogtland/Bohemia at the German/Czech border region in central Europe. There is strong geophysical evidence that there seismic events are correlated to fluid-related processes in the crust. We test the hypothesis that ascending magmatic fluids trigger earthquakes by the mechanism of pore pressure diffusion. This triggering process is mainly controlled by two physical fields, the hydraulic diffusivity and the seismic criticality (i.e., critical pore pressure value leading to failure; stable locations are characterized by higher critical pressures

  9. Insights into pulverized rock formation from dynamic rupture models of earthquakes

    Science.gov (United States)

    Payne, R. M.; Duan, B.

    2017-02-01

    Pulverized rocks (PR) are extremely incohesive and highly fractured rocks found within the damage zones of several large strike-slip faults around the world. They maintain their crystal structure, show little evidence of shearing or chemical alteration, and are believed to be produced by strong tensile forces. Several mechanisms for pulverization have been proposed based on simple qualitative analyses or laboratory experiments under simplified loading conditions. Numerical modelling, however, can offer new insights into what is needed to produce PR and likely conditions of formation. We perform dynamic rupture simulations of different earthquakes, varying the magnitude, the slip distribution, and the rupture speed (supershear and subshear), while measuring the stresses produced away from the fault. To contextualize our results, a basic threshold of 10 MPa is set as the tensile strength of the rock mass and recordings are made of where, when, and by how much this threshold is exceeded for each earthquake type. Guided by field observations, we discern that a large (>Mw 7.1) subshear earthquake along a bimaterial fault produces a pulverized rock distribution most consistent with observations. The damage is asymmetric with the majority on the stiffer side of the fault extending out for several hundred metres. Within this zone there is a large and sudden volumetric expansion in all directions as the rupture passes. We propose that such an extreme tensile stress state, repeated for every earthquake, eventually produces the PR seen in the field.

  10. Design of Earthquake Resistant Bridges Using Rocking Columns

    OpenAIRE

    Barthes, Clement Benjamin

    2012-01-01

    The California Department of Transportation (CalTrans) is urging researchers and contractors to develop the next generation highway bridge design. New design solutions should favor the use of modular construction techniques over conventional cast-in-place reinforced concrete in order to reduce the cost of the projects and the amount of constructions on site. Earthquake resistant bridges are designed such that the columns are monolithically connected to the girder and the foundations. Hence, d...

  11. Shock Waves Trigger Fault Weakening in Calcite-bearing Rocks During Earthquakes

    Science.gov (United States)

    Spagnuolo, E.; Plumper, O.; Violay, M.; Cavallo, A.; Di Toro, G.

    2014-12-01

    The weakening mechanism of calcite-bearing rocks is still poorly understood though many major earthquakes stroke within carbonate sequences. Insights derive from the laboratory: in experiments performed on calcite-bearing gouges, up to 90% drop in friction is associated to grain size reduction to the nanoscale and the formation of crystal-plastic microstructures suggesting the activation of debated weakening mechanisms (e.g., grain boundary sliding and diffusion creep; nanopowder lubrication). Whatever the case, it is unclear how nanoparticles form and what their role is at the initiation of sliding. To investigate initial fault instability we sheared with a rotary shear apparatus SHIVA pre-cut ring-shaped solid cylinders (50/30 mm ext/int diameter) of Carrara marble (99.9% CaCO3). Rock cylinders were slid for few millimetres(0, 1.5 mm and 5mm) at accelerations (6.5 ms-2) and normal stresses (10 MPa) approaching seismic deformation conditions. Initial slip (nano-fracturing have occurred preserving the grain shape (pulverization) and (3) reaction products attributable to high pressure and high temperature conditions (i.e. calcite decomposition into amorphous carbon rimming the nanograins). All the above features are typical of shock-induced changes in minerals. We interpret the above observations as follows: pre-existing grain boundaries or newly formed defects are the nuclei for the generation of dislocations and for their pile-up; the fast release of those piles-up in avalanches under rapid stress loading (fast moving dislocations) may explain the origin of such a shock-like behaviour responsible for large initial frictional weakening. The passage of the shock wave induces pervasive nanofracturing with grain size reduction to the nano-scale and an abrupt temperature rise responsible for calcite decarbonation and formation of carbon amorphous material.

  12. NEESROCK: A Physical and Numerical Modeling Investigation of Seismically Induced Rock-Slope Failure

    Science.gov (United States)

    Applegate, K. N.; Wartman, J.; Keefer, D. K.; Maclaughlin, M.; Adams, S.; Arnold, L.; Gibson, M.; Smith, S.

    2013-12-01

    Worldwide, seismically induced rock-slope failures have been responsible for approximately 30% of the most significant landslide catastrophes of the past century. They are among the most common, dangerous, and still today, least understood of all seismic hazards. Seismically Induced Rock-Slope Failure: Mechanisms and Prediction (NEESROCK) is a major research initiative that fully integrates physical modeling (geotechnical centrifuge) and advanced numerical simulations (discrete element modeling) to investigate the fundamental mechanisms governing the stability of rock slopes during earthquakes. The research is part of the National Science Foundation-supported Network for Earthquake Engineering Simulation Research (NEES) program. With its focus on fractures and rock materials, the project represents a significant departure from the traditional use of the geotechnical centrifuge for studying soil, and pushes the boundaries of physical modeling in new directions. In addition to advancing the fundamental understanding of the rock-slope failure process under seismic conditions, the project is developing improved rock-slope failure assessment guidelines, analysis procedures, and predictive tools. Here, we provide an overview of the project, present experimental and numerical modeling results, discuss special considerations for the use of synthetic rock materials in physical modeling, and address the suitability of discrete element modeling for simulating the dynamic rock-slope failure process.

  13. Rare normal faulting earthquake induced by subduction megaquake: example from 2011 Tohoku-oki earthquake

    Science.gov (United States)

    Ishiyama, T.; Sugito, N.; Echigo, T.; Sato, H.; Suzuki, T.

    2012-04-01

    A month after March 11 gigantic M9.0 Tohoku-oki earthquake, M7.0 intraplate earthquake occurred at a depth of 5 km on April 11 beneath coastal area of near Iwaki city, Fukushima prefecture. Focal mechanism of the mainshock indicates that this earthquake is a normal faulting event. Based on field reconnaissance and LIDAR mapping by Geospatial Information Authority of Japan, we recognized coseismic surface ruptures, presumably associated with the main shock. Coseismic surface ruptures extend NNW for about 11 km in a right-stepping en echelon manner. Geomorphic expressions of these ruptures commonly include WWS-facing normal fault scarps and/or drape fold scarp with open cracks on their crests, on the hanging wall sides of steeply west-dipping normal fault planes subparallel to Cretaceous metamorphic rocks. Highest topographic scarp height is about 2.3 m. In this study we introduce preliminary results of a trenching survey across the coseismic surface ruptures at Shionohira site, to resolve timing of paleoseismic events along the Shionohira fault. Trench excavations were carried out at two sites (Ichinokura and Shionohira sites) in Iwaki, Fukushima. At Shionohira site a 2-m-deep trench was excavated across the coseismic fault scarp emerged on the alluvial plain on the eastern flank of the Abukuma Mountains. On the trench walls we observed pairs of steeply dipping normal faults that deform Neogene to Paleogene conglomerates and unconformably overlying, late Quaternary to Holocene fluvial units. Sense of fault slip observed on the trench walls (large dip-slip with small sinistral component) is consistent with that estimated from coseismic surface ruptures. Fault throw estimated from separation of piercing points on lower Unit I and vertical structural relief on folded upper Unit I is consistent with topographic height of the coseismic fault scarp at the trench site. In contrast, vertical separation of Unit II, unconformably overlain by Unit I, is measured as about 1.5 m

  14. Study on fault induced rock bursts

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-hua; DOU Lin-ming; LU Cai-ping; MU Zong-long; CAO An-ye

    2008-01-01

    In order to study the rules of rock bursts caused by faults by means of mechanical analysis of a roof rock-mass balanced structure and numerical simulation about fault slip destabilization, the effect of coal mining operation on fault plane stresses and slip displacement were studied. The results indicate that the slip displacement sharply increases due to the decrease of normal stress and the increase of shear stress at the fault plane when the working face advances from the footwall to the fault itself, which may induce a fault rock burst. However, this slip displacement will be very small due to the increase of normal stress and the decrease of shear stress when the working face advances from the hanging wall to the fault itself, which results in a very small risk of a fault rock burst.

  15. Electro-Magnetic Earthquake Bursts and Critical Rupture of Peroxy Bond Networks in Rocks

    CERN Document Server

    Freund, F

    2006-01-01

    We propose a mechanism for the low frequency electromagnetic emissions and other electromagnetic phenomena which have been associated with earthquakes. The mechanism combines the critical earthquake concept and the concept of crust acting as a charging electric battery under increasing stress. The electric charges are released by activation of dormant charge carriers in the oxygen anion sublattice, called peroxy bonds or positive hole pairs (PHP), where a PHP represents an $O_3X/^{OO}\\backslash YO_3$ with $X,Y = Si^{4+}, Al^{3+}...$, i.e. an $O^-$ in a matrix of $O^{2-}$ of silicates. We propose that PHP are activated by plastic deformations during the slow cooperative build-up of stress and the increasingly correlated damage culminating in a large ``critical'' earthquake. Recent laboratory experiments indeed show that stressed rocks form electric batteries which can release their charge when a conducting path closes the equivalent electric circuit. We conjecture that the intermittent and erratic occurrences ...

  16. Source characteristics of long runout rock avalanches triggered by the 2008 Wenchuan earthquake, China

    Science.gov (United States)

    Qi, Shengwen; Xu, Qiang; Zhang, Bing; Zhou, Yuande; Lan, Hengxing; Li, Lihui

    2011-03-01

    The May 12, 2008 Wenchuan, China Earthquake which measured M w = 8.3 according to Chinese Earthquake Administration - CEA ( M w = 7.9 according to the USGS) directly triggered many landslides, which caused about 20,000 deaths, a quarter of the total. Rock avalanches were among the most destructive landslides triggered by this seismic event, and have killed more people than any other type of landslide in this earthquake. The Donghekou rock avalanche, one example of a catastrophic avalanche triggered by the Wenchuan earthquake, occurred in Qingchuan and buried one primary school and 184 houses, resulting in more than 780 deaths, and in addition, caused the formation of two landslide dams, which formed barrier lakes. Combining aerial images (resolution of 0.5 m) with field investigations, this paper lists some parameters of 66 cases in one table, and details source characteristics of six typical cases. It has been found that most of the long runout rock avalanches have source areas with high relief and steep inclination, causing the debris in the travel courses to accelerate. There was also a large amount of saturated Holocene-age loose deposits formed by a river or gully that existed in the travel courses. Comparison studies indicate that saturated Holocene loose deposits in the travel courses could be the most important factor for the causes of the long runout characteristic of the rock avalanches especially when they traveled over gentle or even flat ground surfaces. Furthermore, the relationships among the relief slope gradient, runout and covered area are investigated, and a threshold line for predicting the maximum horizontal runout distance under certain change in elevation is presented.

  17. Correlation of pre-earthquake electromagnetic signals with laboratory and field rock experiments

    Directory of Open Access Journals (Sweden)

    T. Bleier

    2010-09-01

    Full Text Available Analysis of the 2007 M5.4 Alum Rock earthquake near San José California showed that magnetic pulsations were present in large numbers and with significant amplitudes during the 2 week period leading up the event. These pulsations were 1–30 s in duration, had unusual polarities (many with only positive or only negative polarities versus both polarities, and were different than other pulsations observed over 2 years of data in that the pulse sequence was sustained over a 2 week period prior to the quake, and then disappeared shortly after the quake. A search for the underlying physics process that might explain these pulses was was undertaken, and one theory (Freund, 2002 demonstrated that charge carriers were released when various types of rocks were stressed in a laboratory environment. It was also significant that the observed charge carrier generation was transient, and resulted in pulsating current patterns. In an attempt to determine if this phenomenon occurred outside of the laboratory environment, the authors scaled up the physics experiment from a relatively small rock sample in a dry laboratory setting, to a large 7 metric tonne boulder comprised of Yosemite granite. This boulder was located in a natural, humid (above ground setting at Bass Lake, Ca. The boulder was instrumented with two Zonge Engineering, Model ANT4 induction type magnetometers, two Trifield Air Ion Counters, a surface charge detector, a geophone, a Bruker Model EM27 Fourier Transform Infra Red (FTIR spectrometer with Sterling cycle cooler, and various temperature sensors. The boulder was stressed over about 8 h using expanding concrete (Bustartm, until it fractured into three major pieces. The recorded data showed surface charge build up, magnetic pulsations, impulsive air conductivity changes, and acoustical cues starting about 5 h before the boulder actually broke. These magnetic and air conductivity pulse signatures resembled both the laboratory

  18. Anomalous winter snow amplified earthquake induced disaster of the 2015 Langtang avalanche in Nepal

    OpenAIRE

    Fujita, Koji; Inoue, Hiroshi; Izumi, Takeki; Yamaguchi, Satoru; Sadakane, Ayako; Sunako, Sojiro; Nishimura, Kouichi; Immerzeel, Walter W.; Shea, Joseph M.; Kayashta, Rijan B.; SAWAGAKI, Takanobu; Breashears, David F.; Yagi, Hiroshi; Sakai, Akiko

    2016-01-01

    Co-seismic avalanches and rock falls, and their simultaneous air blasts, which were induced by the 2015 Gorkha earthquake in Nepal, destroyed the village of Langtang. In order to reveal volume and structure of the deposit covering the village, and sequence of the multiple events, we conducted an intensive in-situ observation in October 2015. Multi-temporal digital elevation models created from photographs taken by helicopter and unmanned aerial vehicles reveal that the deposit volumes of the ...

  19. Mechanical and hydraulic properties of rocks related to induced seismicity

    Science.gov (United States)

    Witherspoon, P.A.; Gale, J.E.

    1977-01-01

    Witherspoon, P.A. and Gale, J.E., 1977. Mechanical and hydraulic properties of rocks related to induced seismicity. Eng. Geol., 11(1): 23-55. The mechanical and hydraulic properties of fractured rocks are considered with regard to the role they play in induced seismicity. In many cases, the mechanical properties of fractures determine the stability of a rock mass. The problems of sampling and testing these rock discontinuities and interpreting their non-linear behavior are reviewed. Stick slip has been proposed as the failure mechanism in earthquake events. Because of the complex interactions that are inherent in the mechanical behavior of fractured rocks, there seems to be no simple way to combine the deformation characteristics of several sets of fractures when there are significant perturbations of existing conditions. Thus, the more important fractures must be treated as individual components in the rock mass. In considering the hydraulic properties, it has been customary to treat a fracture as a parallel-plate conduit and a number of mathematical models of fracture systems have adopted this approach. Non-steady flow in fractured systems has usually been based on a two-porosity model, which assumes the primary (intergranular) porosity contributes only to storage and the secondary (fracture) porosity contributes only to the overall conductivity. Using such a model, it has been found that the time required to achieve quasi-steady state flow in a fractured reservoir is one or two orders of magnitude greater than it is in a homogeneous system. In essentially all of this work, the assumption has generally been made that the fractures are rigid. However, it is clear from a review of the mechanical and hydraulic properties that not only are fractures easily deformed but they constitute the main flow paths in many rock masses. This means that one must consider the interaction of mechanical and hydraulic effects. A considerable amount of laboratory and field data is now

  20. 3-D Numerical Investigation of the Tsaoling Landslide Induced by Chi-Chi Earthquake, Taiwan.

    Science.gov (United States)

    Tang, C.; Hu, J.

    2004-12-01

    Large landslides occurred in the mountainous area near the epicenter of the Sept. 21st, 1999, Chi-Chi earthquake in central Taiwan. These landslides were triggered by the Mw = 7.6 earthquake, which resulted in more than 2,400 human casualties and widespread damage. The 1999 Chi-Chi earthquake triggered a catastrophic Tsaloing landslide, which mobilized about 0.125 km3 of rock and soil that slid across the Chingshui River and created a 5 km long natural dam. One fifth of the landslide mass dropped into the Chingshui River, the rest jumped over the river. At least five large landslides occurred in Tsaoling area are induced by big earthquake and heavy rainfalls since 1862 to 1999. Geological investigation shows that the prevailing attitude of sedimentary formation is about N45W with a dipping angle of 12S. First we used Remark Method to calculate the stability of slope. The bottom of slope has been eroded by Chingshui stream, and the PGA (Peak Ground Acceleration) in Chi-Chi earthquake was exceeded the yield acceleration along the sliding surface. The landslide mechanism may be including flowing, rolling, bouncing and sliding. The rock on the fault plane during faulting can generate pseudotachylyte resulted from melted rock by frictional heat energy along the sliding surface. The frictional melted rocks were found out in the Chiu-Fen-Erh-Shan collapses. However, we didn¡¦t found out the frictional melted rock in Tsaoling area. If we calculated the kinetic energy which was converted to heat energy, the increase of temperature was enough to melt the rocks on sliding surface. When the rocks on the sliding surface had been melted, the friction on the sliding surface must be decrease. Therefore, the 0.125 km3 debris had sufficient kinetic energy to across Chingshui River to the other side of the river. Using 3D distinct-element modeling (PFC3d code), we try to simulate kinematic process of Tsaoling landslide. Our numerical model was compose of about 10,000 spherical

  1. A study of earthquakes induced by water injection in the Changning salt mine area, SW China

    Science.gov (United States)

    Sun, Xiaolong; Yang, Pengtao; Zhang, Zhiwei

    2017-04-01

    The features of earthquakes induced by water injection in the Changning salt mine area of China were analyzed using the pore pressure diffusion method. The relationships between maximum magnitude, cumulative seismic moment, and cumulative water loss volume were investigated. Results show that increased seismic activities near the Changning salt mine in recent years are closely related to water injection during salt mining. High-pressure water injection over a long period of time caused water to diffuse into rock cracks, which increased pore pressure on faults and induced ruptures. Injection-induced earthquakes were located below the injection sites, mainly aligned NW-SE, with most occurring southeast of the mine area. Such a distribution indicates that seismic activities were affected by anticline structures in the Changning area. Based on pore pressure diffusion considerations, the diffusion coefficient was estimated to be ∼0.15 m2/s, with a slightly lower value west of the injection site than to the east. A semi-logarithmic linear relationship was found between cumulative seismic moment and cumulative water loss volume, while maximum magnitude increased with increasing volume of cumulative water loss. This study may provide reference material for analysis of injection-induced earthquakes and evaluation of the danger of earthquakes induced by water injection.

  2. Water-level changes induced by local and distant earthquakes at Long Valley caldera, California

    Science.gov (United States)

    Roeloffs, E.; Sneed, M.; Galloway, D.L.; Sorey, M.L.; Farrar, C.D.; Howle, J.F.; Hughes, J.

    2003-01-01

    Distant as well as local earthquakes have induced groundwater-level changes persisting for days to weeks at Long Valley caldera, California. Four wells open to formations as deep as 300 m have responded to 16 earthquakes, and responses to two earthquakes in the 3-km-deep Long Valley Exploratory Well (LVEW) show that these changes are not limited to weathered or unconsolidated near-surface rocks. All five wells exhibit water-level variations in response to earth tides, indicating they can be used as low-resolution strainmeters. Earthquakes induce gradual water-level changes that increase in amplitude for as long as 30 days, then return more slowly to pre-earthquake levels. The gradual water-level changes are always drops at wells LKT, LVEW, and CH-10B, and always rises at well CW-3. At a dilatometer just outside the caldera, earthquake-induced strain responses consist of either a step followed by a contractional strain-rate increase, or a transient contractional signal that reaches a maximum in about seven days and then returns toward the pre-earthquake value. The sizes of the gradual water-level changes generally increase with earthquake magnitude and decrease with hypocentral distance. Local earthquakes in Long Valley produce coseismic water-level steps; otherwise the responses to local earthquakes and distant earthquakes are indistinguishable. In particular, water-level and strain changes in Long Valley following the 1992 M7.3 Landers earthquake, 450 km distant, closely resemble those initiated by a M4.9 local earthquake on November 22, 1997, during a seismic swarm with features indicative of fluid involvement. At the LKT well, many of the response time histories are identical for 20 days after each earthquake, and can be matched by a theoretical solution giving the pore pressure as a function of time due to diffusion of a nearby, instantaneous, pressure drop. Such pressure drops could be produced by accelerated inflation of the resurgent dome by amounts too

  3. Toward a comprehensive areal model of earthquake-induced landslides

    Science.gov (United States)

    Miles, S.B.; Keefer, D.K.

    2009-01-01

    This paper provides a review of regional-scale modeling of earthquake-induced landslide hazard with respect to the needs for disaster risk reduction and sustainable development. Based on this review, it sets out important research themes and suggests computing with words (CW), a methodology that includes fuzzy logic systems, as a fruitful modeling methodology for addressing many of these research themes. A range of research, reviewed here, has been conducted applying CW to various aspects of earthquake-induced landslide hazard zonation, but none facilitate comprehensive modeling of all types of earthquake-induced landslides. A new comprehensive areal model of earthquake-induced landslides (CAMEL) is introduced here that was developed using fuzzy logic systems. CAMEL provides an integrated framework for modeling all types of earthquake-induced landslides using geographic information systems. CAMEL is designed to facilitate quantitative and qualitative representation of terrain conditions and knowledge about these conditions on the likely areal concentration of each landslide type. CAMEL is highly modifiable and adaptable; new knowledge can be easily added, while existing knowledge can be changed to better match local knowledge and conditions. As such, CAMEL should not be viewed as a complete alternative to other earthquake-induced landslide models. CAMEL provides an open framework for incorporating other models, such as Newmark's displacement method, together with previously incompatible empirical and local knowledge. ?? 2009 ASCE.

  4. Thermally induced rock stress increment and rock reinforcement response

    Energy Technology Data Exchange (ETDEWEB)

    Hakala, M. [KMS Hakala Oy, Nokia (Finland); Stroem, J.; Nujiten, G.; Uotinen, L. [Rockplan, Helsinki (Finland); Siren, T.; Suikkanen, J.

    2014-07-15

    This report describes a detailed study of the effect of thermal heating by the spent nuclear fuel containers on the in situ rock stress, any potential rock failure, and associated rock reinforcement strategies for the Olkiluoto underground repository. The modelling approach and input data are presented together repository layout diagrams. The numerical codes used to establish the effects of heating on the in situ stress field are outlined, together with the rock mass parameters, in situ stress values, radiogenic temperatures and reinforcement structures. This is followed by a study of the temperature and stress evolution during the repository's operational period and the effect of the heating on the reinforcement structures. It is found that, during excavation, the maximum principal stress is concentrated at the transition areas where the profile changes and that, due to the heating from the deposition of spent nuclear fuel, the maximum principal stress rises significantly in the tunnel arch area of NW/SW oriented central tunnels. However, it is predicted that the rock's crack damage (CD, short term strength) value of 99 MPa will not be exceeded anywhere within the model. Loads onto the reinforcement structures will come from damaged and loosened rock which is assumed in the modelling as a free rock wedge - but this is very much a worst case scenario because there is no guarantee that rock cracking would form a free rock block. The structural capacity of the reinforcement structures is described and it is predicted that the current quantity of the rock reinforcement is strong enough to provide a stable tunnel opening during the peak of the long term stress state, with damage predicted on the sprayed concrete liner. However, the long term stability and safety can be improved through the implementation of the principles of the Observational Method. The effect of ventilation is also considered and an additional study of the radiogenic heating effect on the

  5. Earthquake triggering of landslides in highly jointed rock masses: Reconstruction of the 1783 Scilla rock avalanche (Italy)

    Science.gov (United States)

    Bozzano, Francesca; Lenti, Luca; Martino, Salvatore; Montagna, Alfredo; Paciello, Antonella

    2011-06-01

    The Scilla rock avalanche occurred on 6 February 1783 along the coast of the Calabria region (southern Italy), close to the Messina Strait. It was triggered by a mainshock of the “Terremoto delle Calabrie” seismic sequence, and it induced a tsunami wave responsible for more than 1500 casualties along the neighbouring Marina Grande beach. Based on subaerial and submarine surveys, a 5 × 106 m3 subaerial landslide was identified together with a 3 × 106 m3 submarine scar area, whereas block deposits are present in both the subaerial and submerged regions. A detailed geological reconstruction of the slope was obtained and a geomechanical characterisation of the metamorphic rocks involved in the landslide was performed. Based on this reconstruction, intense jointing conditions of the rock mass can be related to main fault zones parallel and normally oriented to the actual coastline. An engineering geology model of the landslide was devised according to an equivalent continuum approach to evaluate both stiffness and strength of the rock mass within the slope. A finite difference stress-strain numerical modelling of the Scilla landslide was performed under dynamic conditions to back-analyse the landslide trigger as well as local seismic amplifications. This modelling gave new insights into the physical interactions between seismic inputs and slopes, as it demonstrated the fundamental role played by i) the interaction between the seismic input and geological setting of unsheared rock slopes (i.e., without preexisting landslide masses), ii) cumulated strain effects due to seismic sequences, and iii) jointing conditions of the involved rock masses responsible for the seismic amplification of the landslide-prone volume, driving it toward failure conditions.

  6. Earthquakes induced by deep penetrating bombing?

    Institute of Scientific and Technical Information of China (English)

    Serguei Yu. Balassanian

    2005-01-01

    The data of M≥5 earthquakes occurred in one year before and after 4 deep penetrating bombs in the region within 500 km and 1 000 km from the shooting site are presented. The 4 bombs are those happened in 1999 Kosovo of Yugoslavia, the 1991 Baghdad of Iraq, the 2001 Tora Bora of Afghanistan, and the 2003 Kirkuk of Iraq, respectively. The data indicate that the deep penetrating bombs may have remotely triggered some earthquakes. The deep penetrating bombs in seismically active regions should be forbidden.

  7. Rock-falls and liquefaction related phenomena triggered by the June 8, 2008, Mw=6.4 earthquake in NW Peloponnesus, Greece

    Directory of Open Access Journals (Sweden)

    Spyros Pavlides

    2014-02-01

    Full Text Available A strong earthquake (Mw=6.4 occurred in NW Peloponnesus, Greece, on June 8, 2008. The focal mechanism shows a transcurrent kinematics, and based on aftershocks distribution the causative fault is a dextral strike-slip NNE-SSW trending structure. The shock generated severe secondary environmental effects like rock-falls and liquefaction phenomena inducing structural damages and ground failures mainly along the fault strike. Evidence of liquefaction was observed in the area of Kato Achaia and Roupakia villages, while rock-falls were triggered mainly close to the epicentre at the foothills of the Skolis Mountain. Based on a quantitative methodological approach, the ground deformation and failures generated by the event have been investigated. In particular, based on an immediate post-event survey, we mapped in detail the distribution of the earthquake-induced ground failures, defining the areas prone to liquefaction and their associated potential. Moreover, a rock-fall hazard zonation in the area of Skolis Mountain has been developed based on the shadow angle approach, confirming the validity of the safety run-out distance models.

  8. Earthquake-induced Landslidingand Ground Damage In New Zealand

    Science.gov (United States)

    Hancox, G. T.; Perrin, N. D.; Dellow, G. D.

    A study of landsliding caused by 22 historical earthquakes in New Zealand was completed at the end of 1997 (Hancox et al., 1997). The main aims of that study were to determine: (a) the nature and extent of landsliding and other ground damage (sand boils, subsidence and lateral spreading due to soil liquefaction) caused by historical earthquakes; (b) relationships between landsliding and earthquake magnitude, epicentre, faulting, geology and topography; (c) improved environmental criteria and ground classes for assigning MM intensities and seismic hazard assessments in N.Z. The data and results of the 1997 study have recently been summarised and expanded (Hancox et al., in press), and are described in this paper. Relationships developed from these studies indicate that the minimum magnitude for earthquake-induced landsliding (EIL) in N.Z. is about M 5, with significant landsliding occurring at M 6 or greater. The minimum MM intensity for landsliding is MM6, while the most common intensities for significant landsliding are MM7-8. The intensity threshold for soil liquefaction in New Zealand was found to be MM7 for sand boils, and MM8 for lateral spreading, although such effects may also occur at one intensity level lower in highly susceptible materials. The minimum magnitude for liquefaction phenomena in N.Z. is about M 6, compared to M 5 overseas where highly susceptible soils are probably more widespread. Revised environmental response criteria (landsliding, subsidence, liquefaction-induced sand boils and lateral spreading) have also been established for the New Zealand MM Intensity Scale, and provisional landslide susceptibility Ground Classes developed for assigning MM intensities in areas where there are few buildings. Other new data presented include a size/frequency distribution model for earthquake-induced landslides over the last 150 years and a preliminary EIL Opportunity model for N.Z. The application of EIL data and relationships for seismic hazard

  9. Distant, delayed and ancient earthquake-induced landslides

    Science.gov (United States)

    Havenith, Hans-Balder; Torgoev, Almaz; Braun, Anika; Schlögel, Romy; Micu, Mihai

    2016-04-01

    On the basis of a new classification of seismically induced landslides we outline particular effects related to the delayed and distant triggering of landslides. Those cannot be predicted by state-of-the-art methods. First, for about a dozen events the 'predicted' extension of the affected area is clearly underestimated. The most problematic cases are those for which far-distant triggering of landslides had been reported, such as for the 1988 Saguenay earthquake. In Central Asia reports for such cases are known for areas marked by a thick cover of loess. One possible contributing effect could be a low-frequency resonance of the thick soils induced by distant earthquakes, especially those in the Pamir - Hindu Kush seismic region. Such deep focal and high magnitude (>>7) earthquakes are also found in Europe, first of all in the Vrancea region (Romania). For this area and others in Central Asia we computed landslide event sizes related to scenario earthquakes with M>7.5. The second particular and challenging type of triggering is the one delayed with respect to the main earthquake event: case histories have been reported for the Racha earthquake in 1991 when several larger landslides only started moving 2 or 3 days after the main shock. Similar observations were also made after other earthquake events in the U.S., such as after the 1906 San Francisco, the 1949 Tacoma, the 1959 Hebgen Lake and the 1983 Bora Peak earthquakes. Here, we will present a series of detailed examples of (partly monitored) mass movements in Central Asia that mainly developed after earthquakes, some even several weeks after the main shock: e.g. the Tektonik and Kainama landslides triggered in 1992 and 2004, respectively. We believe that the development of the massive failures is a consequence of the opening of tension cracks during the seismic shaking and their filling up with water during precipitations that followed the earthquakes. The third particular aspect analysed here is the use of large

  10. Induced and triggered earthquakes at The Geysers geothermal reservoir

    Science.gov (United States)

    Johnson, Lane R.; Majer, Ernest L.

    2017-05-01

    The Geysers geothermal reservoir in northern California is the site of numerous studies of both seismicity induced by injection of fluids and seismicity triggered by other earthquakes. Data from a controlled experiment in the northwest part of The Geysers in the time period 2011 to 2015 are used to study these induced and triggered earthquakes and possible differences between them. Causal solutions to the elastic equations for a porous medium show how fluid injection generates fast elastic and diffusion waves followed by a much slower diffusive wake. Calculations of fluid increment, fluid pressure and elastic stress are used to investigate both when and why seismic failure takes place. Taking into account stress concentrations caused by material heterogeneity leads to the conclusion that fluid injection by itself can cause seismic activity with no need for tectonic forces. Induced events that occur at early times are best explained by changes in stress rate, while those that occur at later times are best explained by changes in stress. While some of the seismic activity is clearly induced by injection of fluids, also present is triggered seismicity that includes aftershock sequences, swarms of seismicity triggered by other earthquakes at The Geysers and clusters of multiple earthquakes. No basic differences are found between the source mechanisms of these different types of earthquakes.

  11. Glacially induced stresses in sedimentary rocks of northern Poland

    Science.gov (United States)

    Trzeciak, Maciej; Dąbrowski, Marcin

    2016-04-01

    During the Pleistocene large continental ice sheets developed in Scandinavia and North America. Ice-loading caused bending of the lithosphere and outward flow in the mantle. Glacial loading is one of the most prominent tectono-mechanical event in the geological history of northern Poland. The Pomeranian region was subjected several times to a load equivalent of more than 1 km of rocks, which led to severe increase in both vertical and horizontal stresses in the upper crustal rocks. During deglaciation a rapid decrease in vertical stress is observed, which leads to destabilization of the crust - most recent postglacial faults scarps in northern Sweden indicate glacially induced earthquakes of magnitude ~Mw8. The presence of the ice-sheet altered as well the near-surface thermal structure - thermal gradient inversion is still observable in NW Poland. The glacially related processes might have left an important mark in the sedimentary cover of northern Poland, especially with regard to fracture reopening, changes in stress state, and damage development. In the present study, we model lithospheric bending caused by glacial load, but our point of interest lies in the overlying sediments. Typical glacial isostatic studies model the response of (visco-) elastic lithosphere over viscoelastic or viscous asthenosphere subjected to external loads. In our model, we introduce viscoelastic sedimentary layers at the top of this stack and examine the stress relaxation patterns therein. As a case study for our modelling, we used geological profiles from northern Poland, near locality of Wejherowo, which are considered to have unconventional gas potential. The Paleozoic profile of this area is dominated by almost 1 km thick Silurian-Ordovician shale deposits, which are interbedded with thin and strong limestone layers. This sequence is underlain by Cambrian shales and sandstones, and finally at ~3 km depth - Precambrian crystalline rocks. Above the Silurian there are approximately

  12. Pre-earthquake signals – Part I: Deviatoric stresses turn rocks into a source of electric currents

    Directory of Open Access Journals (Sweden)

    F. T. Freund

    2007-09-01

    Full Text Available Earthquakes are feared because they often strike so suddenly. Yet, there are innumerable reports of pre-earthquake signals. Widespread disagreement exists in the geoscience community how these signals can be generated in the Earth's crust and whether they are early warning signs, related to the build-up of tectonic stresses before major seismic events. Progress in understanding and eventually using these signals has been slow because the underlying physical process or processes are basically not understood. This has changed with the discovery that, when igneous or high-grade metamorphic rocks are subjected to deviatoric stress, dormant electronic charge carriers are activated: electrons and defect electrons. The activation increases the number density of mobile charge carriers in the rocks and, hence, their electric conductivity. The defect electrons are associated with the oxygen anion sublattice and are known as positive holes or pholes for short. The boundary between stressed and unstressed rock acts a potential barrier that lets pholes pass but blocks electrons. Therefore, like electrons and ions in an electrochemical battery, the stress-activated electrons and pholes in the "rock battery" have to flow out in different directions. When the circuit is closed, the battery currents can flow. The discovery of such stress-activated currents in crustal rocks has far-reaching implications for understanding pre-earthquake signals.

  13. The Upper Limit Size of Reservoir-Induced Earthquakes

    Institute of Scientific and Technical Information of China (English)

    Huang Fuqiong; Zhang Yan; Wu Zhongliang; Ma Lijie

    2008-01-01

    We showed the relation between the magnitude of induced earthquake and the reservoir storage and dam height based on the global catalog from 1967 to 1989 compiled by Ding Yuanzhang (1989). By multiplying reservoir storage with dam height, we introduced a new parameter named EE. We found that the cases with specific EE and magnitude do not exceed a limit. Based on the discussion of its physics, we called EE the equivalent energy. We considered this limit as the upper limit of magnitude for reservoir-induced earthquakes. The result was proved by the recent cases occurring in China. This size limitation can be used as a helpful consideration for reservoir design.

  14. Earthquakes Induced by Hydraulic Fracturing in Poland Township, Ohio

    Science.gov (United States)

    Skoumal, R.; Brudzinski, M. R.; Currie, B. S.

    2014-12-01

    Felt seismicity induced by hydraulic fracturing is very rare with only a handful of reported cases worldwide. Using an optimized multi-station cross-correlation template matching routine, 77 earthquakes were identified in Poland Township, Mahoning County, Ohio that were closely related spatially and temporally to active hydraulic fracturing operations. We identified earthquakes as small as M ~1 up to M 3, one of the largest earthquakes induced by hydraulic fracturing in the United States. These events all occurred 4-12 March 2014 and the rate decayed once the Ohio Department of Natural Resources issued a shutdown of hydraulic fracturing at a nearby well on 10 March. Using a locally derived velocity model and double difference relocation, the earthquake epicenters occurred during six stimulation stages along two horizontal well legs that were located ~0.8 km away. Nearly 100 stages in nearby wells at greater distances from the earthquake source region did not coincide with detected seismicity. During the sequence, hypocenters migrated ~600 m along an azimuth of 083 degrees defining a vertically oriented plane of seismicity close to the top of the Precambrian basement. The focal mechanism determined for the M 3 event had a vertically oriented left-lateral fault plane consistent with the earthquake distribution and the regional stress field. The focal mechanism, orientation, and depth of hypocenters were similar to that of the 2011 Youngstown earthquake sequence that occurred ~20 km away, but was correlated with wastewater injection instead of hydraulic fracturing. Considering the relatively large magnitude of these events and the b-value of 0.85, it appears the hydraulic fracturing induced slip along a pre-existing fault/fracture zone optimally oriented in the regional stress field.

  15. Kinematic Analyses of Rock Slope Failures Triggered by the Aysén 2007 Earthquake (Patagonia, Chile)

    Science.gov (United States)

    Glüer, F.; Loew, S.

    2012-04-01

    Most studies related to earthquake triggering of rock slope failures are statistical investigations of the relationships between earthquake source properties to the spatial distribution of various landslide types, or strongly simplified dynamic stability analyses. Only very few investigators studied the detailed structural and kinematic properties of earthquake triggered rock slope failures. In this paper we present a detailed structural and kinematic analysis of ten rockslides with volumes ranging from 9,000 to 1,000,000 m3 triggered by the Aysén Fjord Mw 6.2 earthquake of April 2007 (Southern Chile). Detailed structural data from the release areas in the steep and only rarely accessible terrain were generated from ground-based photogrammetry, combined with geodetic surveying using a rangefinder binocular connected to a GPS through a GIS-interface. The orientations of discontinuities and release planes were measured in metric 3D images using the software ShapeMetriX3D. Kinematic analyses were applied using Markland methods with Hocking refinement to study possible failure mechanisms. Strength properties of fractures, rock and rock mass were assessed both from field work and laboratory tests on granodioritic and granitic samples. A detailed stability analysis of one selected rockslide was performed with simplified limit equilibrium methods and a two-dimensional numerical FE simulation using the code Phase2. Based on the structural inventory from all release areas a regional structural analysis was performed, showing four evident systematic discontinuity sets (215/75, 275/55, 110/60, 155/65) occurring in the entire study area, and exerting a major control on the location of slope failures. A generic kinematic analysis leads to the conclusion that the distribution of earthquake-triggered rock slope failures of April 2007 is mainly controlled by the slope aspect and slope angle in relationship to these fracture set orientations, with preferential planar failure on

  16. Stress drops of induced and tectonic earthquakes in the central United States are indistinguishable.

    Science.gov (United States)

    Huang, Yihe; Ellsworth, William L; Beroza, Gregory C

    2017-08-01

    Induced earthquakes currently pose a significant hazard in the central United States, but there is considerable uncertainty about the severity of their ground motions. We measure stress drops of 39 moderate-magnitude induced and tectonic earthquakes in the central United States and eastern North America. Induced earthquakes, more than half of which are shallower than 5 km, show a comparable median stress drop to tectonic earthquakes in the central United States that are dominantly strike-slip but a lower median stress drop than that of tectonic earthquakes in the eastern North America that are dominantly reverse-faulting. This suggests that ground motion prediction equations developed for tectonic earthquakes can be applied to induced earthquakes if the effects of depth and faulting style are properly considered. Our observation leads to the notion that, similar to tectonic earthquakes, induced earthquakes are driven by tectonic stresses.

  17. Gravity-induced stresses in stratified rock masses

    Science.gov (United States)

    Amadei, B.; Swolfs, H.S.; Savage, W.Z.

    1988-01-01

    This paper presents closed-form solutions for the stress field induced by gravity in anisotropic and stratified rock masses. These rocks are assumed to be laterally restrained. The rock mass consists of finite mechanical units, each unit being modeled as a homogeneous, transversely isotropic or isotropic linearly elastic material. The following results are found. The nature of the gravity induced stress field in a stratified rock mass depends on the elastic properties of each rock unit and how these properties vary with depth. It is thermodynamically admissible for the induced horizontal stress component in a given stratified rock mass to exceed the vertical stress component in certain units and to be smaller in other units; this is not possible for the classical unstratified isotropic solution. Examples are presented to explore the nature of the gravity induced stress field in stratified rock masses. It is found that a decrease in rock mass anisotropy and a stiffening of rock masses with depth can generate stress distributions comparable to empirical hyperbolic distributions previously proposed in the literature. ?? 1988 Springer-Verlag.

  18. Assessing a 3D smoothed seismicity model of induced earthquakes

    Science.gov (United States)

    Zechar, Jeremy; Király, Eszter; Gischig, Valentin; Wiemer, Stefan

    2016-04-01

    As more energy exploration and extraction efforts cause earthquakes, it becomes increasingly important to control induced seismicity. Risk management schemes must be improved and should ultimately be based on near-real-time forecasting systems. With this goal in mind, we propose a test bench to evaluate models of induced seismicity based on metrics developed by the CSEP community. To illustrate the test bench, we consider a model based on the so-called seismogenic index and a rate decay; to produce three-dimensional forecasts, we smooth past earthquakes in space and time. We explore four variants of this model using the Basel 2006 and Soultz-sous-Forêts 2004 datasets to make short-term forecasts, test their consistency, and rank the model variants. Our results suggest that such a smoothed seismicity model is useful for forecasting induced seismicity within three days, and giving more weight to recent events improves forecast performance. Moreover, the location of the largest induced earthquake is forecast well by this model. Despite the good spatial performance, the model does not estimate the seismicity rate well: it frequently overestimates during stimulation and during the early post-stimulation period, and it systematically underestimates around shut-in. In this presentation, we also describe a robust estimate of information gain, a modification that can also benefit forecast experiments involving tectonic earthquakes.

  19. A preliminary regional assessment of earthquake-induced landslide susceptibility for Vrancea Seismic Region

    Science.gov (United States)

    Micu, Mihai; Balteanu, Dan; Ionescu, Constantin; Havenith, Hans; Radulian, Mircea; van Westen, Cees; Damen, Michiel; Jurchescu, Marta

    2015-04-01

    In seismically-active regions, earthquakes may trigger landslides enhancing the short-to-long term slope denudation and sediment delivery and conditioning the general landscape evolution. Co-seismic slope failures present in general a low frequency - high magnitude pattern which should be addressed accordingly by landslide hazard assessment, with respect to the generally more frequent precipitation-triggered landslides. The Vrancea Seismic Region, corresponding to the curvature sector of the Eastern Romanian Carpathians, represents the most active sub-crustal (focal depth > 50 km) earthquake province of Europe. It represents the main seismic energy source throughout Romania with significant transboundary effects recorded as far as Ukraine and Bulgaria. During the last 300 years, the region featured 14 earthquakes with M>7, among which seven events with magnitude above 7.5 and three between 7.7 and 7.9. Apart from the direct damages, the Vrancea earthquakes are also responsible for causing numerous other geohazards, such as ground fracturing, groundwater level disturbances and possible deep-seated landslide occurrences (rock slumps, rock-block slides, rock falls, rock avalanches). The older deep-seated landslides (assumed to have been) triggered by earthquakes usually affect the entire slope profile. They often formed landslide dams strongly influencing the river morphology and representing potential threats (through flash-floods) in case of lake outburst. Despite the large potential of this research issue, the correlation between the region's seismotectonic context and landslide predisposing factors has not yet been entirely understood. Presently, there is a lack of information provided by the geohazards databases of Vrancea that does not allow us to outline the seismic influence on the triggering of slope failures in this region. We only know that the morphology of numerous large, deep-seated and dormant landslides (which can possibly be reactivated in future

  20. Induced earthquake during the 2016 Kumamoto earthquake (Mw7.0): Importance of real-time shake monitoring for Earthquake Early Warning

    Science.gov (United States)

    Hoshiba, M.; Ogiso, M.

    2016-12-01

    Sequence of the 2016 Kumamoto earthquakes (Mw6.2 on April 14, Mw7.0 on April 16, and many aftershocks) caused a devastating damage at Kumamoto and Oita prefectures, Japan. During the Mw7.0 event, just after the direct S waves passing the central Oita, another M6 class event occurred there more than 80 km apart from the Mw7.0 event. The M6 event is interpreted as an induced earthquake; but it brought stronger shaking at the central Oita than that from the Mw7.0 event. We will discuss the induced earthquake from viewpoint of Earthquake Early Warning. In terms of ground shaking such as PGA and PGV, the Mw7.0 event is much smaller than those of the M6 induced earthquake at the central Oita (for example, 1/8 smaller at OIT009 station for PGA), and then it is easy to discriminate two events. However, PGD of the Mw7.0 is larger than that of the induced earthquake, and its appearance is just before the occurrence of the induced earthquake. It is quite difficult to recognize the induced earthquake from displacement waveforms only, because the displacement is strongly contaminated by that of the preceding Mw7.0 event. In many methods of EEW (including current JMA EEW system), magnitude is used for prediction of ground shaking through Ground Motion Prediction Equation (GMPE) and the magnitude is often estimated from displacement. However, displacement magnitude does not necessarily mean the best one for prediction of ground shaking, such as PGA and PGV. In case of the induced earthquake during the Kumamoto earthquake, displacement magnitude could not be estimated because of the strong contamination. Actually JMA EEW system could not recognize the induced earthquake. One of the important lessons we learned from eight years' operation of EEW is an issue of the multiple simultaneous earthquakes, such as aftershocks of the 2011 Mw9.0 Tohoku earthquake. Based on this lesson, we have proposed enhancement of real-time monitor of ground shaking itself instead of rapid estimation of

  1. An integrated approach for analysing earthquake-induced surface effects: A case study from the Northern Apennines, Italy

    Science.gov (United States)

    Castaldini, D.; Genevois, R.; Panizza, M.; Puccinelli, A.; Berti, M.; Simoni, A.

    This paper illustrates research addressing the subject of the earthquake-induced surface effects by means of a multidisciplinary approach: tectonics, neotectonics, seismology, geology, hydrogeology, geomorphology, soil/rock mechanics have been considered. The research is aimed to verify in areas affected by earthquake-triggered landslides a methodology for the identification of potentially unstable areas. The research was organized according to regional and local scale studies. In order to better emphasise the complexity of the relationships between all the parameters affecting the stability conditions of rock slopes in static and dynamic conditions a new integrated approach, Rock Engineering Systems (RES), was applied in the Northern Apennines. In the paper, the different phases of the research are described in detail and an example of the application of RES method in a sample area is reported. A significant aspect of the study can be seen in its attempt to overcome the exclusively qualitative aspects of research into the relationship between earthquakes and induced surface effects, and to advance the idea of beginning a process by which this interaction can be quantified.

  2. Simulations of explosion-induced damage to underground rock chambers

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A numerical approach is presented to study the explosion-induced pressure load on an underground rock chamber wall and its resultant damage to the rock chamber.Numerical simulations are carried out by using a modified version of the commercial software AUTODYN.Three different criteria,i.e.a peak particle velocity (PPV) criterion,an effective strain (ES) criterion,and a damage criterion,are employed to examine the explosion-induced damaged zones of the underground rock chamber.The results show that the charg...

  3. Modeling the Fluid Withdraw and Injection Induced Earthquakes

    Science.gov (United States)

    Meng, C.

    2016-12-01

    We present an open source numerical code, Defmod, that allows one to model the induced seismicity in an efficient and standalone manner. The fluid withdraw and injection induced earthquake has been a great concern to the industries including oil/gas, wastewater disposal and CO2 sequestration. Being able to numerically model the induced seismicity is long desired. To do that, one has to consider at lease two processes, a steady process that describes the inducing and aseismic stages before and in between the seismic events, and an abrupt process that describes the dynamic fault rupture accompanied by seismic energy radiations during the events. The steady process can be adequately modeled by a quasi-static model, while the abrupt process has to be modeled by a dynamic model. In most of the published modeling works, only one of these processes is considered. The geomechanicists and reservoir engineers are focused more on the quasi-static modeling, whereas the geophysicists and seismologists are focused more on the dynamic modeling. The finite element code Defmod combines these two models into a hybrid model that uses the failure criterion and frictional laws to adaptively switch between the (quasi-)static and dynamic states. The code is capable of modeling episodic fault rupture driven by quasi-static loading, e.g. due to reservoir fluid withdraw and/or injection, and by dynamic loading, e.g. due to the foregoing earthquakes. We demonstrate a case study for the 2013 Azle earthquake.

  4. Earthquake

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    正A serious earthquake happened in Wenchuan, Sichuan. Over 60,000 people died in the earhtquake, millins of people lost their homes. After the earthquake, people showed their love in different ways. Some gave food, medicine and everything necessary, some gave money,

  5. Distribution and features of landslides induced by the 2008 Wengchuan Earthquake, Sichuan, China

    Science.gov (United States)

    Chigira, M.; Xiyong, W.; Inokuchi, T.; Gonghui, W.

    2009-04-01

    2008 Sichuan earthquake with a magnitude of Mw 7.9 induced numerous mass movements around the fault surface ruptures of which maximum separations we observed were 3.6 m vertical and 1.5 m horizontal (right lateral). The affected area was mountainous areas with elevations from 1000 m to 4500 m on the west of the Sichuan Basin. The NE-trending Longmenshan fault zone runs along the boundary between the mountains on the west and the Sichuan basin (He and Tsukuda, 2003), of which Yinghsiuwan-Beichuan fault was the main fault that generated the 2008 earthquake (Xu, 2008). The basement rocks of the mountainous areas range from Precambrian to Cretaceous in age. They are basaltic rocks, granite, phyllite, dolostone, limestone, alternating beds of sandstone and shale, etc. There were several types of landslides ranging from small, shallow rockslide, rockfall, debris slide, deep rockslide, and debris flows. Shallow rockslide, rock fall, and debris slide were most common and occurred on convex slopes or ridge tops. When we approached the epicentral area, first appearing landslides were of this type and the most conspicuous was a failure of isolated ridge-tops, where earthquake shaking would be amplified. As for rock types, slopes of granitic rocks, hornfels, and carbonate rocks failed in wide areas to the most. They are generally hard and their fragments apparently collided and repelled to each other and detached from the slopes. Alternating beds of sandstone and mudstone failed on many slopes near the fault ruptures, including Yinghsiuwan near the epicenter. Many rockfalls occurred on cliffs, which had taluses on their feet. The fallen rocks tumbled down and mostly stopped within the talus surfaces, which is quite reasonable because taluses generally develop by this kind of processes. Many rockslides occurred on slopes of carbonate rocks, in which dolostone or dolomitic limestone prevails. Deep-seated rockslide occurred on outfacing slopes and shallow rockslide and rockfall

  6. Rock magnetic and anisotropy of magnetic susceptibility(AMS) of earthquake affected soft sediments: Examples from Shillong and Latur (Deccan Trap), India.

    Science.gov (United States)

    Lakshmi, B. V., ,, Dr.; Gawali, Mr. Praveen B.; Deenadayalan, K., ,, Dr.; Ramesh, D. S., ,, Prof.

    2017-04-01

    Rock magnetic and anisotropy of magnetic susceptibility (AMS) of earthquake affected soft sediments: Examples from Shillong and Latur (Deccan Trap), India. B.V.Lakshmi, Praveen B.Gawali, K.Deenadayalan and D.S.Ramesh Indian Institute of Geomagnetism, plot 5, sector 18, Near Kalamboli Highway, New Panvel(W), Navi Mumbai 410218 Combined rock magnetism and anisotropy of magnetic susceptibility (AMS) studies on earthquake induced soft and non-soft sediments from Shillong and Latur, India have thrown up interesting results. The morphology of hysteresis loops, the pattern of isothermal remanent magnetization (IRM) acquisition, and temperature dependence of susceptibility indicate that titano-magnetite/magnetite is the main magnetic carrier in these sediments. We also analyzed the anisotropy of magnetic susceptibility (AMS) of liquefaction features within the seismically active Dauki fault, Shillong Plateau. We discovered that host sediments (non-liquefied), are characterized by an oblate AMS ellipsoid and liquefied sediment are characterized by a triaxial AMS ellipsoid, well grouped maximum susceptibility axis K1 (NNW-SSE trend). Field evidence and AMS analysis indicate that most of these features were emplaced by injection inferred to be due to seismically triggered fluidization. Anisotropy of magnetic susceptibility (AMS) of deformed and undeformed unconsolidated clay samples of Deccan Trap terrain from the 2000-year-old paleoearthquake site of Ther village, Maharashtra, India, was also studied. Such deposits are rare in the compact basaltic terrain because of which the results acquired are very important. The undeformed clay samples exhibit typical sedimentary fabric with an oblate AMS ellipsoid, whereas the deformed samples are tightly grouped in the inferred compression direction, probably effected by an earthquake, exhibiting prolate as well as oblate AMS ellipsoids. Rock magnetic and AMS methodology can help understand the behavior of different sediments to the

  7. Phase-transformation-induced lubrication of earthquake sliding.

    Science.gov (United States)

    Green, Harry W

    2017-09-28

    Frictional failure is not possible at depth in Earth, hence earthquakes deeper than 30-50 km cannot initiate by overcoming dry friction. Moreover, the frequency distribution of earthquakes with depth is bimodal, suggesting another change of mechanism at about 350 km. Here I suggest that the change at 30-50 km is from overcoming dry friction to reduction of effective stress by dehydration embrittlement and that the change at 350 km is due to desiccation of slabs and initiation by phase-transformation-induced faulting. High-speed friction experiments at low pressure indicate that exceeding dry friction provokes shear heating that leads to endothermic reactions and pronounced weakening. Higher-pressure studies show nanocrystalline gouge accompanying dehydration and the highest pressure experiments initiate by exothermic polymorphic phase transformation. Here I discuss the characteristic nanostructures of experiments on high-speed friction and high-pressure faulting and show that all simulated earthquake systems yield very weak transformation-induced lubrication, most commonly nanometric gouge or melt. I also show that phase-transformation-induced faulting of olivine to spinel can propagate into material previously transformed to spinel, apparently by triggering melting analogous to high-speed friction studies at low pressure. These experiments taken as a whole suggest that earthquakes at all depths slide at low frictional resistance by a self-healing pulse mechanism with rapid strength recovery.This article is part of the themed issue 'Faulting, friction and weakening: from slow to fast motion'. © 2017 The Author(s).

  8. Distribution characteristics of earthquake-induced landslide with the earthquake source fault-the cases of recent strong earthquakes in eastern Japan

    Science.gov (United States)

    Hasi, B.; Ishii, Y.; Maruyama, K.; Terada, H.

    2009-12-01

    In recent years, 3 strong earthquakes, the Mid-Niigata earthquake (M6.8, October 23, 2004), the Noto Peninsula earthquake (M6.9, March 25, 2007), the Chuetsu-offshore earthquake (M6.8, July 16, 2007), stroke eastern Japan. All of these earthquakes occurred inland by reverse fault, with depth 11-17km hypocenter, triggered a large number of landslides and caused serious damage to the involved regions due to these landslides. To clarify the distribution characteristics of landslides induced by these earthquakes, we interpreted landslides by using aerial photographs taken immediately after the earthquakes, and analyzed landslide distributions with the peak ground acceleration (PGA) and seismic intensity (in Japan Meteorological Agency intensity scale), source fault of the mainshock of each earthquake. The analyzing results revealed that: 1) Most of the landslides occurred in the area where the PGA is larger than 500 gal, and the maximum seismic intensity is larger than 5 plus ; 2) The landslides occurred in a short distance from the source fault (the shortest distance from the surface projection of top tip of the fault), about 80% occurred within the distance of 20 km; 3) More than 80% of landslides occurred on the hanging wall, and the size of landslide (length, width, area) is larger than that occurred on the footwall of the source fault; 4) The number and size of landslide tends to deceases with the distance from the source fault. Our results suggesting that the distance from the source fault of earthquake could be a parameter to analyze the landslide occurrence induce by strong earthquake.

  9. Impact analytical models for earthquake-induced pounding simulation

    Institute of Scientific and Technical Information of China (English)

    Kun YE; Li LI

    2009-01-01

    Structural pounding under earthquake has been recently extensively investigated using various impact analytical models. In this paper, a brief review on the commonly used impact analytical models is conducted.Based on this review, the formula used to determine the damping constant related to the impact spring stiffness,coefficient of restitution, and relative approaching velocity in the Hertz model with nonlinear damping is found to be incorrect. To correct this error, a more accurate approximating formula for the damping constant is theoretically derived 5~nd numerically verified. At the same time, a modified Kelvin impact model, which can reasonably account for the physical nature of pounding and conveniently implemented in the earthquake-induced pounding simulation of structural engineering is proposed.

  10. Observations of a hydrofracture induced earthquake sequence in Harrison County Ohio in 2014

    Science.gov (United States)

    Friberg, P. A.; Brudzinski, M. R.; Currie, B. S.; Skoumal, R.

    2015-12-01

    On October 7, 2014, a Mw 1.9 earthquake was detected and located using the IRIS Earthscope Transportable Array stations in Ohio. The earthquake was located at a depth of ~3 km near the interface of the Paleozoic sedimentary rocks with the crystalline Precambrian basement. The location is within a few kilometers laterally of a 2013 earthquake sequence that was linked to hydraulic fracturing (HF) operations on three wells in Harrison county (Friberg et al, 2014). Using the Mw 1.9 event as a template in a multi-component cross correlation detector on station O53A, over 1000 matching detections were revealed between September 26 - October 17, 2014. These detections were all coincident in time with HF operations on 3 nearby (< 1km away) horizontally drilled wells (Tarbert 1H, 3H, and 5H) in the Utica formation (~2.4 km depth). The HF operations at two of the wells (1H and 5H) were coincident with the majority of the detected events. The final well (3H) stimulated in the series, produced only about 20 identified events. In addition to the coincident timing with nearby HF operations, the time clustered nature of the detections were similar to the 2013 sequence and two other Ohio HF induced sequences in 2014 (Skoumal et al, 2015). All of the other HF induced earthquake sequences in Ohio were related to operations in the Utica formation. Interestingly, this sequence of earthquakes did not follow a simple Gutenberg-Richter magnitude frequency relationship and was deficient in positive magnitude events; the magnitude 1.9 was preceded by a magnitude 1.7, and only a ½ dozen events slightly above magnitude 0.0. The majority of the events detected were below magnitude 0.0, with some as low as magnitude -2.0. While the majority of detections are too small to locate, high similarity in waveform character indicate they are spatially near to the magnitude 1.9 event. Furthermore, gradual shifts in P phase arrival relative to S phases indicate events are moving away from the station

  11. Predicting Ground Motion from Induced Earthquakes in Geothermal Areas

    Science.gov (United States)

    Douglas, J.; Edwards, B.; Convertito, V.; Sharma, N.; Tramelli, A.; Kraaijpoel, D.; Cabrera, B. M.; Maercklin, N.; Troise, C.

    2013-06-01

    Induced seismicity from anthropogenic sources can be a significant nuisance to a local population and in extreme cases lead to damage to vulnerable structures. One type of induced seismicity of particular recent concern, which, in some cases, can limit development of a potentially important clean energy source, is that associated with geothermal power production. A key requirement for the accurate assessment of seismic hazard (and risk) is a ground-motion prediction equation (GMPE) that predicts the level of earthquake shaking (in terms of, for example, peak ground acceleration) of an earthquake of a certain magnitude at a particular distance. Few such models currently exist in regard to geothermal-related seismicity, and consequently the evaluation of seismic hazard in the vicinity of geothermal power plants is associated with high uncertainty. Various ground-motion datasets of induced and natural seismicity (from Basel, Geysers, Hengill, Roswinkel, Soultz, and Voerendaal) were compiled and processed, and moment magnitudes for all events were recomputed homogeneously. These data are used to show that ground motions from induced and natural earthquakes cannot be statistically distinguished. Empirical GMPEs are derived from these data; and, although they have similar characteristics to recent GMPEs for natural and mining-related seismicity, the standard deviations are higher. To account for epistemic uncertainties, stochastic models subsequently are developed based on a single corner frequency and with parameters constrained by the available data. Predicted ground motions from these models are fitted with functional forms to obtain easy-to-use GMPEs. These are associated with standard deviations derived from the empirical data to characterize aleatory variability. As an example, we demonstrate the potential use of these models using data from Campi Flegrei.

  12. Assessment of earthquake-induced landslides hazard in El Salvador after the 2001 earthquakes using macroseismic analysis

    Science.gov (United States)

    Esposito, Eliana; Violante, Crescenzo; Giunta, Giuseppe; Ángel Hernández, Miguel

    2016-04-01

    Two strong earthquakes and a number of smaller aftershocks struck El Salvador in the year 2001. The January 13 2001 earthquake, Mw 7.7, occurred along the Cocos plate, 40 km off El Salvador southern coast. It resulted in about 1300 deaths and widespread damage, mainly due to massive landsliding. Two of the largest earthquake-induced landslides, Las Barioleras and Las Colinas (about 2x105 m3) produced major damage to buildings and infrastructures and 500 fatalities. A neighborhood in Santa Tecla, west of San Salvador, was destroyed. The February 13 2001 earthquake, Mw 6.5, occurred 40 km east-southeast of San Salvador. This earthquake caused over 300 fatalities and triggered several landslides over an area of 2,500 km2 mostly in poorly consolidated volcaniclastic deposits. The La Leona landslide (5-7x105 m3) caused 12 fatalities and extensive damage to the Panamerican Highway. Two very large landslides of 1.5 km3 and 12 km3 produced hazardous barrier lakes at Rio El Desague and Rio Jiboa, respectively. More than 16.000 landslides occurred throughout the country after both quakes; most of them occurred in pyroclastic deposits, with a volume less than 1x103m3. The present work aims to define the relationship between the above described earthquake intensity, size and areal distribution of induced landslides, as well as to refine the earthquake intensity in sparsely populated zones by using landslide effects. Landslides triggered by the 2001 seismic sequences provided useful indication for a realistic seismic hazard assessment, providing a basis for understanding, evaluating, and mapping the hazard and risk associated with earthquake-induced landslides.

  13. Impact of earthquake-induced tsunamis on public health

    Science.gov (United States)

    Mavroulis, Spyridon; Mavrouli, Maria; Lekkas, Efthymios; Tsakris, Athanassios

    2017-04-01

    Tsunamis are caused by rapid sea floor displacement during earthquakes, landslides and large explosive eruptions in marine environment setting. Massive amounts of sea water in the form of devastating surface waves travelling hundreds of kilometers per hour have the potential to cause extensive damage to coastal infrastructures, considerable loss of life and injury and emergence of infectious diseases (ID). This study involved an extensive and systematic literature review of 50 research publications related to public health impact of the three most devastating tsunamis of the last 12 years induced by great earthquakes, namely the 2004 Sumatra-Andaman earthquake (moment magnitude Mw 9.2), the 2009 Samoa earthquake (Mw 8.1) and the 2011 Tōhoku (Japan) earthquake (Mw 9.0) in the Indian, Western Pacific and South Pacific Oceans respectively. The inclusion criteria were literature type comprising journal articles and official reports, natural disaster type including tsunamis induced only by earthquakes, population type including humans, and outcome measure characterized by disease incidence increase. The potential post-tsunami ID are classified into 11 groups including respiratory, pulmonary, wound-related, water-borne, skin, vector-borne, eye, fecal-oral, food-borne, fungal and mite-borne ID. Respiratory infections were detected after all the above mentioned tsunamis. Wound-related, skin and water-borne ID were observed after the 2004 and 2011 tsunamis, while vector-borne, fecal-oral and eye ID were observed only after the 2004 tsunami and pulmonary, food-borne and mite-borne ID were diagnosed only after the 2011 tsunami. Based on available age and genre data, it is concluded that the most vulnerable population groups are males, children (age ≤ 15 years) and adults (age ≥ 65 years). Tetanus and pneumonia are the deadliest post-tsunami ID. The detected risk factors include (1) lowest socioeconomic conditions, poorly constructed buildings and lack of prevention

  14. Induced earthquakes. Sharp increase in central Oklahoma seismicity since 2008 induced by massive wastewater injection.

    Science.gov (United States)

    Keranen, K M; Weingarten, M; Abers, G A; Bekins, B A; Ge, S

    2014-07-25

    Unconventional oil and gas production provides a rapidly growing energy source; however, high-production states in the United States, such as Oklahoma, face sharply rising numbers of earthquakes. Subsurface pressure data required to unequivocally link earthquakes to wastewater injection are rarely accessible. Here we use seismicity and hydrogeological models to show that fluid migration from high-rate disposal wells in Oklahoma is potentially responsible for the largest swarm. Earthquake hypocenters occur within disposal formations and upper basement, between 2- and 5-kilometer depth. The modeled fluid pressure perturbation propagates throughout the same depth range and tracks earthquakes to distances of 35 kilometers, with a triggering threshold of ~0.07 megapascals. Although thousands of disposal wells operate aseismically, four of the highest-rate wells are capable of inducing 20% of 2008 to 2013 central U.S. seismicity.

  15. Applicability of artificial intelligence to reservoir induced earthquakes

    Science.gov (United States)

    Samui, Pijush; Kim, Dookie

    2014-06-01

    This paper proposes to use least square support vector machine (LSSVM) and relevance vector machine (RVM) for prediction of the magnitude (M) of induced earthquakes based on reservoir parameters. Comprehensive parameter (E) and maximum reservoir depth (H) are used as input variables of the LSSVM and RVM. The output of the LSSVM and RVM is M. Equations have been presented based on the developed LSSVM and RVM. The developed RVM also gives variance of the predicted M. A comparative study has been carried out between the developed LSSVM, RVM, artificial neural network (ANN), and linear regression models. Finally, the results demonstrate the effectiveness and efficiency of the LSSVM and RVM models.

  16. Evaluation of the conservativeness of the methodology for estimating earthquake-induced movements of fractures intersecting canisters

    Energy Technology Data Exchange (ETDEWEB)

    La Pointe, Paul R.; Cladouhos, Trenton T. [Golder Associates Inc., Las Vegas, NV (United States); Outters, Nils; Follin, Sven [Golder Grundteknik KB, Stockholm (Sweden)

    2000-04-01

    This study evaluates the parameter sensitivity and the conservativeness of the methodology outlined in TR 99-03. Sensitivity analysis focuses on understanding how variability in input parameter values impacts the calculated fracture displacements. These studies clarify what parameters play the greatest role in fracture movements, and help define critical values of these parameters in terms of canister failures. The thresholds or intervals of values that lead to a certain level of canister failure calculated in this study could be useful for evaluating future candidate sites. Key parameters include: 1. magnitude/frequency of earthquakes; 2. the distance of the earthquake from the canisters; 3. the size and aspect ratio of fractures intersecting canisters; and 4. the orientation of the fractures. The results of this study show that distance and earthquake magnitude are the most important factors, followed by fracture size. Fracture orientation is much less important. Regression relations were developed to predict induced fracture slip as a function of distance and either earthquake magnitude or slip on the earthquake fault. These regression relations were validated by using them to estimate the number of canister failures due to single damaging earthquakes at Aberg, and comparing these estimates with those presented in TR 99-03. The methodology described in TR 99-03 employs several conservative simplifications in order to devise a numerically feasible method to estimate fracture movements due to earthquakes outside of the repository over the next 100,000 years. These simplifications include: 1. fractures are assumed to be frictionless and cohesionless; 2. all energy transmitted to the fracture by the earthquake is assumed to produce elastic deformation of the fracture; no energy is diverted into fracture propagation; and 3. shielding effects of other fractures between the earthquake and the fracture are neglected. The numerical modeling effectively assumes that the

  17. A review of the 2005 Kashmir earthquake-induced landslides; from a remote sensing prospective

    Science.gov (United States)

    Shafique, Muhammad; van der Meijde, Mark; Khan, M. Asif

    2016-03-01

    The 8th October 2005 Kashmir earthquake, in northern Pakistan has triggered thousands of landslides, which was the second major factor in the destruction of the build-up environment, after earthquake-induced ground shaking. Subsequent to the earthquake, several researchers from home and abroad applied a variety of remote sensing techniques, supported with field observations, to develop inventories of the earthquake-triggered landslides, analyzed their spatial distribution and subsequently developed landslide-susceptibility maps. Earthquake causative fault rupture, geology, anthropogenic activities and remote sensing derived topographic attributes were observed to have major influence on the spatial distribution of landslides. These were subsequently used to develop a landslide susceptibility map, thereby demarcating the areas prone to landsliding. Temporal studies monitoring the earthquake-induced landslides shows that the earthquake-induced landslides are stabilized, contrary to earlier belief, directly after the earthquake. The biggest landslide induced dam, as a result of the massive Hattian Bala landslide, is still posing a threat to the surrounding communities. It is observed that remote sensing data is effectively and efficiently used to assess the landslides triggered by the Kashmir earthquake, however, there is still a need of more research to understand the mechanism of intensity and distribution of landslides; and their continuous monitoring using remote sensing data at a regional scale. This paper, provides an overview of remote sensing and GIS applications, for the Kashmir-earthquake triggered landslides, derived outputs and discusses the lessons learnt, advantages, limitations and recommendations for future research.

  18. Physics-based estimates of maximum magnitude of induced earthquakes

    Science.gov (United States)

    Ampuero, Jean-Paul; Galis, Martin; Mai, P. Martin

    2016-04-01

    In this study, we present new findings when integrating earthquake physics and rupture dynamics into estimates of maximum magnitude of induced seismicity (Mmax). Existing empirical relations for Mmax lack a physics-based relation between earthquake size and the characteristics of the triggering stress perturbation. To fill this gap, we extend our recent work on the nucleation and arrest of dynamic ruptures derived from fracture mechanics theory. There, we derived theoretical relations between the area and overstress of overstressed asperity and the ability of ruptures to either stop spontaneously (sub-critical ruptures) or runaway (super-critical ruptures). These relations were verified by comparison with simulation and laboratory results, namely 3D dynamic rupture simulations on faults governed by slip-weakening friction, and laboratory experiments of frictional sliding nucleated by localized stresses. Here, we apply and extend these results to situations that are representative for the induced seismicity environment. We present physics-based predictions of Mmax on a fault intersecting cylindrical reservoir. We investigate Mmax dependence on pore-pressure variations (by varying reservoir parameters), frictional parameters and stress conditions of the fault. We also derive Mmax as a function of injected volume. Our approach provides results that are consistent with observations but suggests different scaling with injected volume than that of empirical relation by McGarr, 2014.

  19. Chemical diagenesis, porosity reduction, and rock strength, IODP Site U1480: Influences on great earthquakes at shallow depths

    Science.gov (United States)

    Song, Insun; Milliken, Kitty; Dugan, Brandon; Bourlange, Sylvain; Colson, Tobias; Frederik, Marina; Jeppson, Tamara; Kuranaga, Mebae; Nair, Nisha; Henstock, Timothy

    2017-04-01

    International Ocean Discovery Program (IODP) Expedition 362 drilled two sites, U1480 and U1481, on the Indian oceanic plate ˜250 km west of the Sunda subduction zone to a maximum depth of 1500 meters below seafloor (mbsf). One of the primary objectives was to understand the mechanism of great earthquakes such as the 2004 Sumatra earthquake (Mw 9.0) which showed unexpectedly shallow megathrust slip by establishing the initial and evolving properties of the North Sumatran incoming sedimentary section. Core sampling and logging from the complete sedimentary section at U1480 indicates a distinct change in sedimentation rate from a slowly deposited pelagic system to a rapidly deposited submarine fan system at late Miocene. Following burial, sediments of the Nicobar Fan underwent compaction leading to porosity reduction from 66±9% near seafloor to ˜30% at the base of the sampled Nicobar Fan section (˜1250 mbsf), representing a normal consolidation behavior. Rock strength gradually increases with depth as the sediments are mechanically compacted. Below the fan (1250-1415 mbsf), the pelagic sediments are composed of tuffaceous, calcareous, and siliceous sediments/rocks and their porosity is dependent upon lithology more than upon depth. Tuffaceous materials exhibit high porosity ranging from ˜30-60%, even higher than that of overlying layers. However, porosity of most calcareous samples is lower than 20% at the same depth. The large variation in porosity depends on the degree of cementation, which in turn is controlled by grain assemblage composition and environmental conditions such as slow sedimentation rates and locally high temperatures related to igneous activity as documented by local igneous intrusives and extrusives. The minor cementation in tuffaceous sandy sediments has retained high porosity, but strengthened their skeleton so as to bear the overburden. The low porosity in calcareous rocks is considered to come from extensive cementation rather than

  20. Earthquake induced landslide hazard field observatory in the Avcilar peninsula

    Science.gov (United States)

    Bigarre, Pascal; Coccia, Stella; Theoleyre, Fiona; Ergintav, Semih; Özel, Oguz; Yalçinkaya, Esref; Lenti, Luca; Martino, Salvatore; Gamba, Paolo; Zucca, Francesco; Moro, Marco

    2015-04-01

    Earthquake-triggered landslides have an increasing disastrous impact in seismic regions due to the fast growing urbanization and infrastructures. Just considering disasters from the last fifteen years, among which the 1999 Chi-Chi earthquake, the 2008 Wenchuan earthquake, and the 2011 Tohoku earthquake, these events generated tens of thousands of coseismic landslides. Those resulted in amazing death toll and considerable damages, affecting the regional landscape including its hydrological main features. Despite a strong impetus in research during past decades, knowledge on those geohazards is still fragmentary, while databases of high quality observational data are lacking. These phenomena call for further collaborative researches aiming eventually to enhance preparedness and crisis management. The MARSITE project gathers research groups in a comprehensive monitoring activity developed in the Sea of Marmara Region, one of the most densely populated parts of Europe and rated at high seismic risk level since the 1999 Izmit and Duzce devastating earthquakes. Besides the seismic threat, landslides in Turkey and in this region constitute an important source of loss. The 6th Work Package of MARSITE project gathers 9 research groups to study earthquake-induced landslides focusing on two sub-regional areas of high interest among which the Cekmece-Avcilar peninsula, located westwards of Istanbul, as a highly urbanized concentrated landslide prone area, showing high susceptibility to both rainfalls while affected by very significant seismic site effects. A multidisciplinary research program based on pre-existing studies has been designed with objectives and tasks linked to constrain and tackle progressively some challenging issues related to data integration, modeling, monitoring and mapping technologies. Since the start of the project, progress has been marked on several important points as follows. The photogeological interpretation and analysis of ENVISAT-ERS DIn

  1. Strain-dependent Damage Evolution and Velocity Reduction in Fault Zones Induced by Earthquake Rupture

    Science.gov (United States)

    Zhong, J.; Duan, B.

    2009-12-01

    Low-velocity fault zones (LVFZs) with reduced seismic velocities relative to the surrounding wall rocks are widely observed around active faults. The presence of such a zone will affect rupture propagation, near-field ground motion, and off-fault damage in subsequent earth-quakes. In this study, we quantify the reduction of seismic velocities caused by dynamic rup-ture on a 2D planar fault surrounded by a low-velocity fault zone. First, we implement the damage rheology (Lyakhovsky et al. 1997) in EQdyna (Duan and Oglesby 2006), an explicit dynamic finite element code. We further extend this damage rheology model to include the dependence of strains on crack density. Then, we quantify off-fault continuum damage distribution and velocity reduction induced by earthquake rupture with the presence of a preexisting LVFZ. We find that the presence of a LVFZ affects the tempo-spatial distribu-tions of off-fault damage. Because lack of constraint in some damage parameters, we further investigate the relationship between velocity reduction and these damage prameters by a large suite of numerical simulations. Slip velocity, slip, and near-field ground motions computed from damage rheology are also compared with those from off-fault elastic or elastoplastic responses. We find that the reduction in elastic moduli during dynamic rupture has profound impact on these quantities.

  2. Geological Investigation and analysis in response to Earthquake Induced Landslide in West Sumatra

    Science.gov (United States)

    Karnawati, D.; Wilopo, W.; Salahudin, S.; Sudarno, I.; Burton, P.

    2009-12-01

    Substantial socio-economical loss occurred in response to the September 30. 2009 West Sumatra Earthquake with magnitude of 7.6. Damage of houses and engineered structures mostly occurred at the low land of alluvium sediments due to the ground amplification, whilst at the high land of mountain slopes several villages were buried by massive debris of rocks and soils. It was recorded that 1115 people died due to this disasters. Series of geological investigation was carried out by Geological Engineering Department of Gadjah Mada University, with the purpose to support the rehabilitation program. Based on this preliminary investigation it was identified that most of the house and engineered structural damages at the alluvial deposits mainly due to by the poor quality of such houses and engineered structures, which poorly resist the ground amplification, instead of due to the control of geological conditions. On the other hand, the existence and distribution of structural geology (faults and joints) at the mountaineous regions are significant in controlling the distribution of landslides, with the types of rock falls, debris flows and debris falls. Despite the landslide susceptibility mapping conducted by Geological Survey of Indonesia, more detailed investigation is required to be carried out in the region surrounding Maninjau Lake, in order to provide safer places for village relocation. Accordingly Gadjah Mada University in collaboration with the local university (Andalas University) as well as with the local Government of Agam Regency and the Geological Survey of Indonesia, serve the mission for conducting rather more detailed geological and landslide investigation. It is also crucial that the investigation (survey and mapping) on the social perception and expectation of local people living in this landslide susceptible area should also be carried out, to support the mitigation effort of any future potential earthquake induced landslides.

  3. Seismic Documentation for Rock Damage and Heal on the San Andreas Fault Involved in the 2004 M6 Parkfield Earthquake

    Science.gov (United States)

    Malin, P. M.; Li, Y.; Chen, P.; Cochran, E. M.; Vidale, J. E.

    2007-12-01

    After the M6 Parkfield earthquake that occurred on 28 September 2004, we deployed a dense seismic array at the same sites as used in our experiment in the fall of 2002. The measurements using moving-window cross- correlation of waveforms for the repeated explosions and microearthquakes recorded in 2002 and 2004 show a decrease in shear velocity of at least ~2.5% within a ~200-m-wide zone across the San Andreas main fault trace most likely owing to co-seismic damage of fault rocks caused by dynamic rupture in this M6 earthquake. The width of the damage zone characterized by larger velocity changes is consistent with the low-velocity waveguide model on the SAF near Parkfield derived from fault-zone trapped waves [Li et al., 2004]. The estimated ratio between the P and S wave traveltime changes is 0.57 within the rupture zone and ~0.65 in the surrounding rocks, indicating wetter cracks within the damaged fault zone, probably due to the ground water percolating into the cracks opened in the mainshock. The measurements of traveltime changes for repeated aftershocks in 21 clusters, with a total of ~130 events, located at different depths along the rupture in 2004 show that the maximum shear velocity increased by ~1.2% within the damage zone in 3.5 months starting a week after the mainshock, indicating that the fault heals in the post-seismic stage due to the closure of cracks in the damaged rock. The data recorded at a seismograph installed in the SAFOD mainhole passing the San Andreas fault zone at ~3-km depths for repeated aftershocks in December of 2004 and later show that seismic velocities within the damage zone were changed by ~0.3% in a month, but no changes were registered at seismographs installed in the vertical pilot borehole drilled ~1.8 km away from the main fault trace for the same repeated events. We find that the healing rate is logarithmically decreasing through time with greater healing rate in the earlier stage after the mainshock. The magnitude of

  4. The 2008 Wenchuan earthquake induced landslides and associated induced debris flows

    NARCIS (Netherlands)

    Tang, C.; van Asch, Th.W.J.

    2012-01-01

    The 12 May 2008 Wenchuan earthquake (Mw = 8.0) induced widespread and large scale landslidesover an area of about 50,OOO km', some of which al$o produced many fatalitiesand extensive damage to housing settlements and irrigation channels, In addition, highways and bridges were destroyed, and the city

  5. Spectral analysis of dike-induced earthquakes in Afar, Ethiopia

    Science.gov (United States)

    Tepp, Gabrielle; Ebinger, Cynthia J.; Yun, Sang-Ho

    2016-04-01

    Shallow dike intrusions may be accompanied by fault slip above the dikes, a superposition which complicates seismic and geodetic data analyses. The diverse volcano-tectonic and low-frequency local earthquakes accompanying the 2005-2010 large-volume dike intrusions in the Dabbahu-Manda Hararo rift (Afar), some with fault displacements of up to 3 m at the surface, provide an opportunity to examine the relations among the earthquakes, dike intrusions, and surface ruptures. We apply the frequency index (FI) method to characterize the spectra of swarm earthquakes from six of the dikes. These earthquakes often have broad spectra with multiple peaks, making the usual peak frequency classification method unreliable. Our results show a general bimodal character with high FI earthquakes associated with deeper dikes (top > 3 km subsurface) and low FI earthquakes associated with shallow dikes, indicating that shallow dikes result in earthquakes with more low-frequency content and larger-amplitude surface waves. Low FI earthquakes are more common during dike emplacement, suggesting that interactions between the dike and faults may lead to lower FI. Taken together, likely source processes for low FI earthquakes are shallow hypocenters (<3 km) possibly with surface rupture, slow rupture velocities, and interactions with dike fluids. Strong site effects also heavily influence the earthquake spectral content. Additionally, our results suggest a continuum of spectral responses, implying either that impulsive volcano-tectonic earthquakes and the unusual, emergent earthquakes have similar source processes or that simple spectral analyses, such as FI, cannot distinguish different source processes.

  6. Newmark displacement model for landslides induced by the 2013 Ms 7.0 Lushan earthquake, China

    Science.gov (United States)

    Yuan, Renmao; Deng, Qinghai; Cunningham, Dickson; Han, Zhujun; Zhang, Dongli; Zhang, Bingliang

    2016-12-01

    Predicting approximate earthquake-induced landslide displacements is helpful for assessing earthquake hazards and designing slopes to withstand future earthquake shaking. In this work, the basic methodology outlined by Jibson (1993) is applied to derive the Newmark displacement of landslides based on strong ground-motion recordings during the 2013 Lushan Ms 7.0 earthquake. By analyzing the relationships between Arias intensity, Newmark displacement, and critical acceleration of the Lushan earthquake, formulas of the Jibson93 and its modified models are shown to be applicable to the Lushan earthquake dataset. Different empirical equations with new fitting coefficients for estimating Newmark displacement are then developed for comparative analysis. The results indicate that a modified model has a better goodness of fit and a smaller estimation error for the Jibson93 formula. It indicates that the modified model may be more reasonable for the dataset of the Lushan earthquake. The analysis of results also suggests that a global equation is not ideally suited to directly estimate the Newmark displacements of landslides induced by one specific earthquake. Rather it is empirically better to perform a new multivariate regression analysis to derive new coefficients for the global equation using the dataset of the specific earthquake. The results presented in this paper can be applied to a future co-seismic landslide hazard assessment to inform reconstruction efforts in the area affected by the 2013 Lushan Ms 7.0 earthquake, and for future disaster prevention and mitigation.

  7. Geological control of earthquake induced landslide in El Salvador

    Science.gov (United States)

    Tsige Aga, Meaza

    2010-05-01

    Geological control of earthquake induced landslides in El Salvador. M., Tsige(1), I., Garcia-Flórez(1), R., Mateos(2) (1)Universidad Complutense de Madrid, Facultad de Geología, Madrid, Spain, (meaza@geo.ucm.es) (2)IGME, Mallorca El Salvador is located at one of the most seismically active areas en Central America, and suffered severe damage and loss of life in historical and recent earthquakes, as a consequence of earthquake induced landslides. The most common landslides were shallow disrupted soil-slides on steep slopes and were particularly dense in the central part of the country. Most of them are cited in the recent mechanically weak volcanic pyroclastic deposits known as "Tierra Blanca" and "Tierra Color Café" which are prone to seismic wave amplification and are supposed to have contributed to the triggering of some of the hundreds of landslides related to the 2001 (Mw = 7.6 and Mw = 6.7), seismic events. The earthquakes also triggered numerous deep large scale landslides responsible for the enormous devastation of villages and towns and are the source for the current high seismic hazard as well. Many of these landslides are located at distances more than 50 and 100 km from the focal distance, although some of them occurred at near field. Until now there has been little effort to explain the causes and concentration of the deep large-scale landslides especially their distribution, failure mechanism and post-rapture behavior of the landslide mass (long run-out). It has been done a field investigation of landslides, geological materiales and interpretation of aerial photographs taken before and after the two 2001 (Mw= 7.6 and Mw= 6.7) El Salvador earthquakes. The result of the study showed that most of the large-scale landslides occured as coherent block slides with the sliding surface parallel to a pre-existing fractures and fault planes (La Leona, Barriolera, El Desague, Jiboa landslides). Besides that the pre-existing fractures are weak zones controlling

  8. Fluid-rock interactions in seismic faults : implications from the structures and mineralogical and geochemical compositions of drilling cores from the rupture of the 2008 Wenchuan earthquake, China

    NARCIS (Netherlands)

    Duan, Qingbao; Yang, Xiaosong; Ma, Shengli; Chen, J.|info:eu-repo/dai/nl/370819071; Chen, Jinyu

    2016-01-01

    We describe the structural features and mineralogical and geochemical compositions of the fault rocks recovered from boreholes at the Golden River site on the Yingxiu–Beichuan fault, which activated and slipped along a 240 km-long main surface rupture zone during the 2008 Wenchuan earthquake. The

  9. Fluid-rock interactions in seismic faults : implications from the structures and mineralogical and geochemical compositions of drilling cores from the rupture of the 2008 Wenchuan earthquake, China

    NARCIS (Netherlands)

    Duan, Qingbao; Yang, Xiaosong; Ma, Shengli; Chen, J.; Chen, Jinyu

    2016-01-01

    We describe the structural features and mineralogical and geochemical compositions of the fault rocks recovered from boreholes at the Golden River site on the Yingxiu–Beichuan fault, which activated and slipped along a 240 km-long main surface rupture zone during the 2008 Wenchuan earthquake. The fa

  10. Novel determination of radon-222 velocity in deep subsurface rocks and the feasibility to using radon as an earthquake precursor

    Science.gov (United States)

    Zafrir, Hovav; Ben Horin, Yochai; Malik, Uri; Chemo, Chaim; Zalevsky, Zeev

    2016-09-01

    A novel technique utilizing simultaneous radon monitoring by gamma and alpha detectors to differentiate between the radon climatic driving forces and others has been improved and used for deep subsurface investigation. Detailed long-term monitoring served as a proxy for studying radon movement within the shallow and deep subsurface, as well as for analyzing the effect of various parameters of the radon transport pattern. The main achievements of the investigation are (a) determination, for the first time, of the radon movement velocity within rock layers at depths of several tens of meters, namely, 25 m/h on average; (b) distinguishing between the diurnal periodical effect of the ambient temperature and the semidiurnal effect of the ambient pressure on the radon temporal spectrum; and (c) identification of a radon random preseismic anomaly preceding the Nuweiba, M 5.5 earthquake of 27 June 2015 that occurred within Dead Sea Fault Zone.

  11. Application of scaling-rule theory in crustal rock fracture to studying characteristics of seismological precursors associated with M=6.1 Shandan-Minle earthquake

    Institute of Scientific and Technical Information of China (English)

    RONG Dai-lu; LI Ya-rong; HAN Xiao-ming

    2006-01-01

    In the paper, we introduce Allegre's scaling-rule theory of rock fracture and the probability to develop a method for predicting earthquake occurrence time on its basis. As an example, we study the characteristics of seismological precursors (seismic spatial correlation length and coda Qc) associated with the earthquake (M=6.1) occurred in Shandan-Minle, Gansu Province. The results show an increasing trend of seismic spatial correlation length and coda Qc before the earthquake. And a power exponent relation is used to fit the increasing variation form of these two parameters. The study has provided a basis for creating a method and finding indexes to predict the earthquake occurrence time by using the monitored seismic spatial correlation length and coda Qc.

  12. Induced Polarization Surveying for Acid Rock Screening in Highway Design

    Science.gov (United States)

    Butler, K. E.; Al, T.; Bishop, T.

    2004-05-01

    Highway and pipeline construction agencies have become increasingly vigilant in their efforts to avoid cutting through sulphide-bearing bedrock that has potential to produce acid rock drainage. Blasting and fragmentation of such rock increases the surface area available for sulphide oxidation and hence increases the risk of acid rock drainage unless the rock contains enough natural buffering capacity to neutralize the pH. In December, 2001, the New Brunswick Department of Transportation (NBOT) sponsored a field trial of geophysical surveying in order to assess its suitability as a screening tool for locating near-surface sulphides along proposed highway alignments. The goal was to develop a protocol that would allow existing programs of drilling and geochemical testing to be targeted more effectively, and provide design engineers with the information needed to reduce rock cuts where necessary and dispose of blasted material in a responsible fashion. Induced polarization (IP) was chosen as the primary geophysical method given its ability to detect low-grade disseminated mineralization. The survey was conducted in dipole-dipole mode using an exploration-style time domain IP system, dipoles 8 to 25 m in length, and six potential dipoles for each current dipole location (i.e. n = 1 - 6). Supplementary information was provided by resistivity and VLF-EM surveys sensitive to lateral changes in electrical conductivity, and by magnetic field surveying chosen for its sensitivity to the magnetic susceptibility of pyrrhotite. Geological and geochemical analyses of samples taken from several IP anomalies located along 4.3 line-km of proposed highway confirmed the effectiveness of the screening technique. IP pseudosections from a region of metamorphosed shales and volcaniclastic rocks identified discrete, well-defined mineralized zones. Stronger, overlapping, and more laterally extensive IP anomalies were observed over a section of graphitic and sulphide-bearing metasedimentary

  13. Uncertainty Analysis of Static Coulomb Stress Change Induced by Earthquake A Case Study on the 2008 Ms 8.0 Wenchuan Earthquake

    Institute of Scientific and Technical Information of China (English)

    Wang Liwei; Chen Qifu

    2012-01-01

    Static Coulomb stress change induced by earthquake slip is frequently used to explain earthquake activities and aftershock distribution. However, some parameters for the Coulomb stress calculation are unable to be well constrained from laboratory experiments and field observations. Different parameters may directly affect the pattern of static Coulomb stress. The static Coulomb stress changes induced by the Wenchuan earthquake calculated by six research groups are not consistent with each other. To investigate how the parameters affect the calculation results, we change the parameters in turn through modeling and compare the results of different calculation parameters. We find that gravity, position and strike of receiver faults have little influence on coseismic Coulomb stress calculations, but other parameters can change the value and sign of the results in various degrees especially around the earthquake rupture plane. Therefore the uncertainty analysis of static Coulomb stress change induced by earthquake should be taken into consideration in the earthquake hazard analysis.

  14. Lichenometry dating of rock collapse related to the great Lisbon Earthquake (1755) at the SE part of Spain

    Science.gov (United States)

    Perez-Lopez, Raul; Rodriguez-Pascua, Miguel Angel; Silva, Pablo G.; Bischoff, James L.; Owen, Lewis A.; Giner-Robles, Jorge L.; Díez-Herrero, Andres

    2010-05-01

    "De una montaña, se desprendió una parte" (A large part of a mountain has fallen down). This sentence was extracted from an ancient text written at the end of the 18th Century, in relation with the great Earthquake of Lisbon in 1755 (Martínez-Solares, 2001), and describing the rock collapse recorded near the small town of Agramón, 50 km southeastward of Albacete city (SE of Spain). Up to now, archaeologists have suggested this rock collapse to the archaeological site of "El Tolmo de Minateda", a small butte (420 m long) of calcarenitic sandstone bedrock with a flat top and scarped cliffs (20m high) bordering the butte. This ancient city was habited by several civilizations from Bronze Ages to modern times (i.e. Iberians, Roman, Visigoths, Muslims, Medieval ages, etc.). The landscape of this area is characterized by a flat terrain with isolated relict structural buttes consisting of Late Neogene marine sandstones created by differential erosion. The site exhibits three different stages of massive rock collapse. The oldest is located at the north of the site while the younger is located at the south part of the site and affecting Visigothic stone carved tombs. Archaeologists have postulated that the youngest of these was triggered by the Lisbon earthquake of 1755. We have carried out a lichenometric analysis over the free-faces of the rock blocks, with the aim of testing the postulate. For our purpose, we have calculated the calibrated growth curve for Aspicilia Radiosa (Hoff.), which yields a linear growth of 0.2425 mm per yr (R2 = 0.97, N=20). This growth rate was determined for the time interval from 800 BP yrs to the present by two different approaches: (1) rates obtained from cemetery measurements (200 yrs BP) and (2) rates determined from well-dated archaeological monuments (200-800 yrs BP). Our analysis revealed that the age of the rock-falling was in the year 1754 AD ±4. Thus, our results confirm that this collapse of ca. 5000 m3 of volume was triggered

  15. Numerical Analyses of Earthquake Induced Liquefaction and Deformation Behaviour of an Upstream Tailings Dam

    Directory of Open Access Journals (Sweden)

    Muhammad Auchar Zardari

    2017-01-01

    Full Text Available Much of the seismic activity of northern Sweden consists of micro-earthquakes occurring near postglacial faults. However, larger magnitude earthquakes do occur in Sweden, and earthquake statistics indicate that a magnitude 5 event is likely to occur once every century. This paper presents dynamic analyses of the effects of larger earthquakes on an upstream tailings dam at the Aitik copper mine in northern Sweden. The analyses were performed to evaluate the potential for liquefaction and to assess stability of the dam under two specific earthquakes: a commonly occurring magnitude 3.6 event and a more extreme earthquake of magnitude 5.8. The dynamic analyses were carried out with the finite element program PLAXIS using a recently implemented constitutive model called UBCSAND. The results indicate that the magnitude 5.8 earthquake would likely induce liquefaction in a limited zone located below the ground surface near the embankment dikes. It is interpreted that stability of the dam may not be affected due to the limited extent of the liquefied zone. Both types of earthquakes are predicted to induce tolerable magnitudes of displacements. The results of the postseismic slope stability analysis, performed for a state after a seismic event, suggest that the dam is stable during both the earthquakes.

  16. Reliability Based assessment of buildings under earthquakes due to gas extraction

    NARCIS (Netherlands)

    Steenbergen, R.D.J.M.; Vrouwenvelder, A.C.W.M.

    2014-01-01

    In the northern part of the Netherlands over de last decades shallow earthquakes are induced due to large scale gas extraction from the Groningen gas field. Earthquakes occur due to the compaction of the reservoir rock, which leads to subsidence at surface and strain build-up in the reservoir rock

  17. Reliability Based assessment of buildings under earthquakes due to gas extraction

    NARCIS (Netherlands)

    Steenbergen, R.D.J.M.; Vrouwenvelder, A.C.W.M.

    2014-01-01

    In the northern part of the Netherlands over de last decades shallow earthquakes are induced due to large scale gas extraction from the Groningen gas field. Earthquakes occur due to the compaction of the reservoir rock, which leads to subsidence at surface and strain build-up in the reservoir rock a

  18. Linking fossil reefs with earthquakes: Geologic insight to where induced seismicity occurs in Alberta

    Science.gov (United States)

    Schultz, Ryan; Corlett, Hilary; Haug, Kristine; Kocon, Ken; MacCormack, Kelsey; Stern, Virginia; Shipman, Todd

    2016-03-01

    Recently, a significant increase in North American, midcontinent earthquakes has been associated with contemporaneous development of petroleum resources. Despite the proliferation of drilling throughout sedimentary basins worldwide, earthquakes are only induced at a small fraction of wells. In this study, we focus on cases of induced seismicity where high-resolution data are available in the central Western Canada Sedimentary Basin. Our regional comparison of induced earthquake depths suggests basement-controlled tectonics. Complementary to these findings, hypocenters of induced seismicity clusters coincide with the margins of Devonian carbonate reefs. We interpret this spatial correspondence as the result of geographically biased activation potential, possibly as a consequence of reef nucleation preference to paleobathymetric highs associated with Precambrian basement tectonics. This finding demonstrates the importance of geologic/tectonic factors to earthquake induction, in addition to industrial operational parameters. In fact, the observation of induced seismicity silhouetting deep fossil reef systems may be a useful tool to identify future regions with increased seismogenic potential.

  19. Were the 1952 Kern County and 1933 Long Beach, California, Earthquakes Induced?

    Science.gov (United States)

    Hough, S. E.; Tsai, V. C.; Walker, R. L., II; Page, M. T.; Aminzadeh, F.

    2016-12-01

    Several recent studies have presented evidence that significant induced earthquakes occurred in a number of regions during the 20th century related to either production or early wastewater injection. We consider whether the Mw6.4 Long Beach and Mw7.3 1952 Kern County earthquakes might have been induced by production in the Huntington Beach and Wheeler Ridge oil fields, respectively. The Long Beach earthquake occurred within 9 months of the start of directional drilling that first exploited offshore tideland reserves at depths of ≈1200 m; the well location was within ≈3 km of the event epicenter. The Kern County earthquake occurred 111 days following the first exploitation of deep Eocene production horizons within the Wheeler Ridge field at depths reaching 3 km, within ≈1 km of the White Wolf fault (WWF); the epicenter of this earthquake is poorly constrained but the preferred epicenter is within ≈7 km of the well. While production in the Wheeler Ridge field would have reduced pore pressure, likely inhibiting failure on the WWF assuming a Coulomb failure criteria, we present a model based on analytical solutions with model parameters constrained from detailed industry data, whereby direct pore pressure effects were blocked by a normal fault that created an impermeable barrier close to the WWF, allowing the normal stress change associated with production to dominate, thereby promoting failure by unclamping the fault. Our proposed triggering mechanism is consistent with the observation that significant earthquakes are only rarely induced by production in proximity to major faults. Our results also suggest that significant induced earthquakes in southern California during the early 20th century might have been associated with industry practices that are no longer employed (i.e., production without water re-injection). The occurrence of significant earthquakes during the earthquake 20th century therefore does not necessarily imply a high likely of induced

  20. A Stress Condition in Aquifer Rock for Detecting Anomalous Radon Decline Precursory to an Earthquake

    Science.gov (United States)

    Kuo, T.; Kuochen, H.; Ho, C.; Chen, W.

    2016-12-01

    Recurrent groundwater radon anomalous declines were observed from well measurements in the Antung hot spring area (eastern Taiwan) prior to five of six earthquakes that occurred between 2003 and 2011 (M w range 5.0-6.8). The relationship between the detectability of radon anomalies and the first motions of P-waves was investigated. Based on the first motions of P-waves recorded near the investigated well, a precursory decrease in groundwater radon can be detected only when the first motion is compression. No precursory change in groundwater radon concentration was observed for the downward first motion of P-waves.

  1. A Stress Condition in Aquifer Rock for Detecting Anomalous Radon Decline Precursory to an Earthquake

    Science.gov (United States)

    Kuo, T.; Kuochen, H.; Ho, C.; Chen, W.

    2017-03-01

    Recurrent groundwater radon anomalous declines were observed from well measurements in the Antung hot spring area (eastern Taiwan) prior to five of six earthquakes that occurred between 2003 and 2011 ( M w range 5.0-6.8). The relationship between the detectability of radon anomalies and the first motions of P-waves was investigated. Based on the first motions of P-waves recorded near the investigated well, a precursory decrease in groundwater radon can be detected only when the first motion is compression. No precursory change in groundwater radon concentration was observed for the downward first motion of P-waves.

  2. Earthquake response of concrete arch dams with layered rock foundation in time domain with a case study of an arch dam in Iran

    Energy Technology Data Exchange (ETDEWEB)

    Barikani, A. [Tabriz Univ., Tehran (Iran, Islamic Republic of). Dept. of Civil Engineering; Hashemiravan, M. [Varamin Azad Univ., Tehran (Iran, Islamic Republic of). Dept. of Civil Engineering

    2006-07-01

    This study examined the dynamic behaviour of an arch dam and the interactions between the dam and its layered rock foundation. The seismic response of the Amir Kabir dam located in Iran was investigated using a 3-D finite element model. The rock foundation of the dam was divided into 3 areas: high resistance rock, medium resistance rock, and low resistance rock. The hydrodynamic effects of water were modelled using an added mass method with concentrate masses in nodes of elements on the upstream face of the dam body. Earthquake response of the dam was demonstrated using a time history of displacement at the dam crest, contours of maximum tensile stresses, and maximum pressure stresses on the upstream and downstream face of the dam. The study also examined issues concerning tensile cracks that occurred as a result of an actual earthquake. Results showed that the maximum tensile stress in the upstream face of the dam was 2.5 times more than allowable limits for tensile stress in concrete. The maximum pressure stress was lower than allowable limits. A comparison between the time history of the principal stresses at different points of the dam demonstrated that maximum tensile stress occurred in the middle of the dam. However pressure was highest near the foundation level. Results showed that the tensile cracks in the dam crest area were caused by the excessive amounts of tensile stress. It was also concluded that the earthquake used in the study was in the design basis earthquake (DBE) category, with a return period of approximately 200 years. 7 refs., 5 tabs., 10 figs.

  3. ROCK COMPRESSION AND SHEAR FRACTURE NUCLEUS AND INTRAPLATE EARTHQUAKES%岩石压剪断裂核与板块内部地震

    Institute of Scientific and Technical Information of China (English)

    周群力; 刘振洪; 刘樵; 刘清波

    2011-01-01

    The earthquakes in China's mainland belong to intraplate earthquakes. The seismogenic mechanism is that the rocks break zone with special shape-rock compression and shear fracture nucleus forming by the end of original fault cause the fault expansion, under the action of the stress. The model has been confirmed by geological remains of earthquake source in Danjiang. Theory is consistent with experiment results and geological remains, and same for micro and macro phenomena. By laboratory studies, series results such as rock strength of compression and shear, dilatancy and expansive stress after rock broken, compression-shear fracture criterion, closed cracks surface stress transferring to the ends of the cracks and closed crack surface appearing opening displacement before fracture in the process of compression and shear fracture test, are all obtained. According to the rock compression and shear fracture nucleus mode analysis, rock breaking in the compression shear fracture nucleus takes place before the earthquake, deriving thermal infrared and many other phenomena. Abnormal change appears before the impending earthquake. Therefore, intraplate earthquakes are predictable.%在中国大陆内部发生的地震属于地球板块内部地震.它的发震机制是在应力作用下,原有断层裂面端部形成特殊形状的岩石破碎区——岩石压剪断裂核而导致断层扩展.该模式已被单江震源地质遗存所证实,且理论、试验、遗存一致,微观、宏观相符.通过试验研究,取得岩石压剪强度、岩石破碎后的扩容与膨胀应力、压剪断裂判据、压剪断裂试验过程中闭合裂缝面应力向缝端转移及断裂前闭合裂缝面出现开位等系列结果.根据岩石压剪断裂核模式分析,压剪断裂核内岩石破碎先于地震发生,衍生热红外等诸多现象,在临震前显现异动.因此,板内地震的发生具有可预测性.

  4. Earthquake Induced Landslides In The Watershed Of The Imo River

    Science.gov (United States)

    Watanabe, N.; Marui, H.; Yoshimatsu, H.

    2005-05-01

    The 2004 Niigata Chuetsu earthquake induced >1600 landslides in various types and dimensions. It has been general understanding until now that because of strong ground shaking during earthquakes a lot of slope failures occur on the steep slopes but only few reactivated landslides occur on gentle slopes. However, also many reactivated landslides occurred in the neighborhood of the epicenter area especially in the Yamakoshi Village. Landslides induced by the earthquake can be classified manly into the following categories: (1) Shallow slope failures on steep slopes near ridges, (2) Shallow slope failures on steep slopes along river channels, (3) Reactivated landslides on gentle hillslopes, (4) Landslide dams were formed by the displaced soils mass by the previous three categories. For the mitigation of subsequent disaster, it was a matter of great urgency to implement emergency countermeasures against overtopping and failure of the landslide dams. The Yamakoshi Village locates on the Higashiyama Hills trending a NNE-SSW direction with the altitude between 400m and 700m. The Imo River is flowing through eastern part of the village. The geology around the village belongs to Pliocene and Pleistocene formations that consist mainly of mudstone, sandstone and their alternation. The geological structure is controlled by the anticlines and synclines almost parallel to the direction of the hills. Landslides occurred especially densely in the watershed of the Imo River along the Kajigane Syncline and slipped along dip direction of geologic formations. Originally, heavily landslide prone areas are widely distributed in the Tertiary mudstone areas in Niigata Prefecture. Reactivated landslides occur frequently in the western part of the village where the mudstone is distributed. This time most of landslides occurred in the western part of the village where the sandstone is distributed. More than 30 landslide dams were formed along the main channel of the river and its tributaries

  5. Estimation of rock movements due to future earthquakes at four candidate sites for a spent fuel repository in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Pointe, P. La [Golder Associates Inc. (United States); Hermanson, J. [Golder Associates AB (Sweden)

    2002-02-01

    Numerical simulations of the displacements of fractures intersecting canisters due to future seismicity have been carried out for the Olkiluoto, Kivetty, Hastholmen and Romuvaara sites. The numerical simulation process uses stochastic models of repository-scale natural fracturing, as well as the magnitude and frequency of future earthquakes within a 100 km radius of the repositories. Future seismicity is based on the extrapolation of the current earthquake catalog for each region. Earthquakes with magnitudes greater than ML = 5.5 (up to 7 - 8) are relegated to the post glacial period at the end of the 100 000 year simulation interval. There are uncertainties related to these assumptions, as the magnitude-frequency distribution of seismicity is likely different in the post-glacial period. Future earthquakes are located on lineament segments of sufficient size for the specified magnitude that have been mapped within the 100 km circular region. The orientation of the lineament and the sense of slip on the fault are selected based upon current seismicity, and depend upon whether the future earthquake is post-glacial or not. The repository-scale fracture model is constructed from the analysis of borehole and outcrop fracture data, as well as lineament data at scales ranging from 1:20 000 to 1:1 000 000. Scaling analysis indicates that both lineament and outcrop scale data can be combined to construct the repository scale fracture model. The results of the fracture analyses are numerically implemented as Discrete Fracture Network (DFN) models. One hundred stochastic realizations of both the repository-scale DFN model and future seismicity were combined with canister layouts for each site to provide the input data for earthquake simulations using a three-dimensional linearly elastic fracture mechanics code. The amount of induced slip on fractures intersecting canisters was tabulated for all of the stochastic realizations for each of the four sites. Statistics on canister

  6. Source mechanism inversion and ground motion modeling of induced earthquakes in Kuwait - A Bayesian approach

    Science.gov (United States)

    Gu, C.; Toksoz, M. N.; Marzouk, Y.; Al-Enezi, A.; Al-Jeri, F.; Buyukozturk, O.

    2016-12-01

    The increasing seismic activity in the regions of oil/gas fields due to fluid injection/extraction and hydraulic fracturing has drawn new attention in both academia and industry. Source mechanism and triggering stress of these induced earthquakes are of great importance for understanding the physics of the seismic processes in reservoirs, and predicting ground motion in the vicinity of oil/gas fields. The induced seismicity data in our study are from Kuwait National Seismic Network (KNSN). Historically, Kuwait has low local seismicity; however, in recent years the KNSN has monitored more and more local earthquakes. Since 1997, the KNSN has recorded more than 1000 earthquakes (Mw Institutions for Seismology (IRIS) and KNSN, and widely felt by people in Kuwait. These earthquakes happen repeatedly in the same locations close to the oil/gas fields in Kuwait (see the uploaded image). The earthquakes are generally small (Mw < 5) and are shallow with focal depths of about 2 to 4 km. Such events are very common in oil/gas reservoirs all over the world, including North America, Europe, and the Middle East. We determined the location and source mechanism of these local earthquakes, with the uncertainties, using a Bayesian inversion method. The triggering stress of these earthquakes was calculated based on the source mechanisms results. In addition, we modeled the ground motion in Kuwait due to these local earthquakes. Our results show that most likely these local earthquakes occurred on pre-existing faults and were triggered by oil field activities. These events are generally smaller than Mw 5; however, these events, occurring in the reservoirs, are very shallow with focal depths less than about 4 km. As a result, in Kuwait, where oil fields are close to populated areas, these induced earthquakes could produce ground accelerations high enough to cause damage to local structures without using seismic design criteria.

  7. Geomorphic changes induced by the April-May 2015 earthquake sequence in the Pharak-Khumbu area (Nepal): preliminary assessments.

    Science.gov (United States)

    Fort, Monique

    2016-04-01

    Landsliding is a common process shaping mountain slopes. There are various potential landslide triggers (rainfall, bank erosion, earthquakes) and their effectiveness depends on their distribution, frequency and magnitude. In a Himalayan context, the effects of monsoon rainfall can be assessed every year whereas the unpredictability and low frequency of large earthquakes make their role in triggering slope instability more obscure. A 7.8 magnitude earthquake struck central Nepal (Gorkha District) on 25 April 2015 and was followed by many aftershocks exceeding magnitude 5, including another strong 7.3 magnitude earthquake on May 12, 2015 (Dolakha District). This seismic crisis provides an exceptional opportunity to assess the disruptions that earthquakes may cause in "regular" geomorphic systems controlled by rainfall. Here we present field observations carried out in the Pharak-Khumbu area (East Nepal, Dudh Kosi catchment) before and after the April-May 2015 earthquakes. The Pharak, a "middle mountains" (2000-4500 m) area, is affected by monsoon rains (3000 m/yr at 2500 m) and characterised by steep hillslopes, shaped by different geomorphic processes according to slope height and aspect, rock type and strength, inherited landforms, stream connectivity and current land use changes. This study focuses on the south of Lukla (Phakding District), and more specifically on the Khari Khola catchment and its surroundings. The area lies at the transition between the Higher Himalayan crystallines and the Lesser Himalayan meta-sediments. On the basis of our diachronic observations (March and November 2015), we surveyed and mapped new earthquake-induced slope instabilities such as rock falls, rockslides, landslides and debris flows and a combination of several of them. Interviews with local people also helped to assess the exact timing of some events. While the first M 7.8 earthquake produced significant impacts in the northern Khumbu area, the M 7.3 aftershock seems to have

  8. Shock-induced damage in rocks: Application to impact cratering

    Science.gov (United States)

    Ai, Huirong

    Shock-induced damage beneath impact craters is studied in this work. Two representative terrestrial rocks, San Marcos granite and Bedford limestone, are chosen as test target. Impacts into the rock targets with different combinations of projectile material, size, impact angle, and impact velocity are carried out at cm scale in the laboratory. Shock-induced damage and fracturing would cause large-scale compressional wave velocity reduction in the recovered target beneath the impact crater. The shock-induced damage is measured by mapping the compressional wave velocity reduction in the recovered target. A cm scale nondestructive tomography technique is developed for this purpose. This technique is proved to be effective in mapping the damage in San Marcos granite, and the inverted velocity profile is in very good agreement with the result from dicing method and cut open directly. Both compressional velocity and attenuation are measured in three orthogonal directions on cubes prepared from one granite target impacted by a lead bullet at 1200 m/s. Anisotropy is observed from both results, but the attenuation seems to be a more useful parameter than acoustic velocity in studying orientation of cracks. Our experiments indicate that the shock-induced damage is a function of impact conditions including projectile type and size, impact velocity, and target properties. Combined with other crater phenomena such as crater diameter, depth, ejecta, etc., shock-induced damage would be used as an important yet not well recognized constraint for impact history. The shock-induced damage is also calculated numerically to be compared with the experiments for a few representative shots. The Johnson-Holmquist strength and failure model, initially developed for ceramics, is applied to geological materials. Strength is a complicated function of pressure, strain, strain rate, and damage. The JH model, coupled with a crack softening model, is used to describe both the inelastic response of

  9. Seismic Induced Ionospheric Disturbances: Characteristics observed from 2012 Indian Ocean Doublet Earthquake and 2014 Chile Pisagua Earthquake

    Science.gov (United States)

    Sunil Kumar, A. S.

    2016-07-01

    Large earthquakes (Mw > 6.5) can induce near and far-field ionospheric perturbations by direct/secondary acoustic and gravity waves through Lithosphere-Atmosphere-Ionosphere (LAI) coupling. The earthquake generated pressure waves grow in amplitude by about five orders of magnitude as they propagate upward and produce ionosphere electron density perturbations. In addition to the ground vertical motion near the seismic rupture area, horizontally propagating Rayleigh surface waves also induce acoustic waves into the nearby neutral atmosphere, which arrive at the ionospheric altitudes and generate electron density variations there within 10 minutes after the initial Earth's surface motion. It is also observed that tsunami waves in the ocean generate gravity waves that propagate obliquely upwards and interact with the ionospheric electron density. In the present study, we tried to explore the characteristics of seismic induced ionospheric electron density variations following Indian Ocean doublet and Pisagua earthquakes. The April 11, 2012 Indian Ocean doublet earthquake was a unique event because of its largest ever recorded aftershock (Mw = 8.2) occurred after two hours of the main shock (Mw = 8.6). Approximately 10 min after both seismic events, the nearby ionosphere started to manifest electron density perturbations that are investigated using GPS-TEC measurements. The epicenters of both events are located south of the magnetic equator, and the magnetic field inclination is one of the factors responsible for the observed north-south asymmetry in the co-seismic total electron content (TEC) disturbances. These disturbances are observed to propagate up to approximately 1500 km towards the north side of the epicenter and up to only a few hundred kilometers on the south side. The frequency analysis of the co-seismic TEC disturbances after both earthquakes exhibits the dominant presence of acoustic frequencies varying between approximately 4.0 to 6.0 mHz. The estimated

  10. Induced and Natural Seismicity: Earthquake Hazards and Risks in Ohio:

    Science.gov (United States)

    Besana-Ostman, G. M.; Worstall, R.; Tomastik, T.; Simmers, R.

    2013-12-01

    To adapt with increasing need to regulate all operations related to both the Utica and Marcellus shale play within the state, ODNR had recently strengthen its regulatory capability through implementation of stricter permit requirements, additional human resources and improved infrastructure. These ODNR's efforts on seismic risk reduction related to induced seismicity led to stricter regulations and many infrastructure changes related particularly to Class II wells. Permit requirement changes and more seismic monitoring stations were implemented together with additional injection data reporting from selected Class II well operators. Considering the possible risks related to seismic events in a region with relatively low seismicity, correlation between limited seismic data and injection volume information were undertaken. Interestingly, initial results showed some indications of both plugging and fracturing episodes. The real-time data transmission from seismic stations and availability of injection volume data enabled ODNR to interact with operators and manage wells dynamically. Furthermore, initial geomorphic and structural analyses indicated possible active faults in the northern and western portion of the state oriented NE-SW. The newly-mapped structures imply possible relatively bigger earthquakes in the region and consequently higher seismic risks. With the above-mentioned recent changes, ODNR have made critical improvement of its principal regulatory role in the state for oil and gas operations but also an important contribution to the state's seismic risk reduction endeavors. Close collaboration with other government agencies and the public, and working together with the well operators enhanced ODNR's capability to build a safety culture and achieve further public and industry participation towards a safer environment. Keywords: Induced seismicity, injection wells, seismic risks

  11. Geomorphological phenomena induced by the El Asnam earthquake, Algeria. Comparison with the Campania earthquake, Italy

    Energy Technology Data Exchange (ETDEWEB)

    Durville, J.L. (Laboratoire central des Ponts et Chaussees, 75 - Paris (France)); Meneroud, J.P. (Laboratoire des Ponts et Chaussees, 06 - Nice (France))

    These two great earthquakes gave rise to quite different geodynamic phenomena, both morphologically and kinetically. At the time of the El Asnam earthquarke the seismic vibration led to liquefaction phenomena and land movements, with two distinct types of surface fracture. In that of Southern Italy the landslides caused by the seismic vibration, beginning a day or two afterwards, were exceptionally severe.

  12. Coseismic water level changes induced by two distant earthquakes in multiple wells of the Chinese mainland

    Science.gov (United States)

    Ma, Yuchuan; Huang, Fuqiong

    2017-01-01

    Coseismic water level oscillations, or step-like rises and step-like drops were recorded in 159 wells throughout the Chinese mainland due to the 2015 Nepal Mw 7.8 earthquake, and 184 wells for the 2011 Japan Mw 9.0 earthquake. The earthquake magnitude, and the associated dynamic stresses, has positive roles in both the sensitivity of water level to earthquake induced change, and the amplitude and duration of resulting coseismic water level changes. Wells whose water levels are sensitive to Earth tides have high potential to response to earthquakes. Polarities of step-like changes (rises or drops) are locally controlled and spatially variable, with artesian wells generally recording water-level rises. Permeability enhancement was assessed as a mechanism responsible for step-like changes by analyzing the tidal phase responses. Permeability variations are inferred for 17 out of 95 wells with step-like changes during the Nepal earthquake and for 32 out of 105 wells following the Japan earthquake; however, only 6 wells have permeability variations after both earthquakes.

  13. Carbon deposition during brittle rock deformation: Changes in electrical properties of fault zones and potential geoelectric phenomena during earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Mathez, E A; Roberts, J J; Duba, A G; Kronenberg, A K; Karner, S L

    2008-05-16

    To investigate potential mechanisms for geoelectric phenomena accompanying earthquakes, we have deformed hollow cylinders of Sioux quartzite to failure in the presence of carbonaceous pore fluids and investigated the resulting changes in electrical conductivity and carbon distribution. Samples were loaded at room temperature or 400 C by a hydrostatic pressure at their outer diameter, increasing pressure at a constant rate to {approx}290 MPa. Pore fluids consisted of pure CO, CO{sub 2}, CH{sub 4} and a 1:1 mixture of CO{sub 2} and CH{sub 4}, each with pore pressures of 2.0 to 4.1 MPa. Failure occurred by the formation of mode II shear fractures transecting the hollow cylinder walls. Radial resistivities of the cylinders fell to 2.9 to 3.1 M{Omega}-m for CO tests and 15.2 to 16.5 M{Omega}-m for CO{sub 2}:CH{sub 4} tests, compared with >23 M{Omega}-m for dry, undeformed cylinders. Carbonaceous fluids had no discernable influence on rock strength. Based on mapping using electron microprobe techniques, carbon occurs preferentially as quasi-continuous films on newly-formed fracture surfaces, but these films are absent from pre-existing surfaces in those same experiments. The observations support the hypothesis that electrical conductivity of rocks is enhanced by the deposition of carbon on fracture surfaces and imply that electrical properties may change in direct response to brittle deformation. They also suggest that the carbon films formed nearly instantaneously as the cracks formed. Carbon film deposition may accompany the development of microfracture arrays prior to and during fault rupture and thus may be capable of explaining precursory and coseismic geoelectric phenomena.

  14. Preliminary Results of Earthquake-Induced Building Damage Detection with Object-Based Image Classification

    Science.gov (United States)

    Sabuncu, A.; Uca Avci, Z. D.; Sunar, F.

    2016-06-01

    Earthquakes are the most destructive natural disasters, which result in massive loss of life, infrastructure damages and financial losses. Earthquake-induced building damage detection is a very important step after earthquakes since earthquake-induced building damage is one of the most critical threats to cities and countries in terms of the area of damage, rate of collapsed buildings, the damage grade near the epicenters and also building damage types for all constructions. Van-Ercis (Turkey) earthquake (Mw= 7.1) was occurred on October 23th, 2011; at 10:41 UTC (13:41 local time) centered at 38.75 N 43.36 E that places the epicenter about 30 kilometers northern part of the city of Van. It is recorded that, 604 people died and approximately 4000 buildings collapsed or seriously damaged by the earthquake. In this study, high-resolution satellite images of Van-Ercis, acquired by Quickbird-2 (Digital Globe Inc.) after the earthquake, were used to detect the debris areas using an object-based image classification. Two different land surfaces, having homogeneous and heterogeneous land covers, were selected as case study areas. As a first step of the object-based image processing, segmentation was applied with a convenient scale parameter and homogeneity criterion parameters. As a next step, condition based classification was used. In the final step of this preliminary study, outputs were compared with streetview/ortophotos for the verification and evaluation of the classification accuracy.

  15. Geomorphic and geologic controls of geohazards induced by Nepal's 2015 Gorkha earthquake.

    Science.gov (United States)

    Kargel, J S; Leonard, G J; Shugar, D H; Haritashya, U K; Bevington, A; Fielding, E J; Fujita, K; Geertsema, M; Miles, E S; Steiner, J; Anderson, E; Bajracharya, S; Bawden, G W; Breashears, D F; Byers, A; Collins, B; Dhital, M R; Donnellan, A; Evans, T L; Geai, M L; Glasscoe, M T; Green, D; Gurung, D R; Heijenk, R; Hilborn, A; Hudnut, K; Huyck, C; Immerzeel, W W; Liming, Jiang; Jibson, R; Kääb, A; Khanal, N R; Kirschbaum, D; Kraaijenbrink, P D A; Lamsal, D; Shiyin, Liu; Mingyang, Lv; McKinney, D; Nahirnick, N K; Zhuotong, Nan; Ojha, S; Olsenholler, J; Painter, T H; Pleasants, M; Pratima, K C; Yuan, Q I; Raup, B H; Regmi, D; Rounce, D R; Sakai, A; Donghui, Shangguan; Shea, J M; Shrestha, A B; Shukla, A; Stumm, D; van der Kooij, M; Voss, K; Xin, Wang; Weihs, B; Wolfe, D; Lizong, Wu; Xiaojun, Yao; Yoder, M R; Young, N

    2016-01-01

    The Gorkha earthquake (magnitude 7.8) on 25 April 2015 and later aftershocks struck South Asia, killing ~9000 people and damaging a large region. Supported by a large campaign of responsive satellite data acquisitions over the earthquake disaster zone, our team undertook a satellite image survey of the earthquakes' induced geohazards in Nepal and China and an assessment of the geomorphic, tectonic, and lithologic controls on quake-induced landslides. Timely analysis and communication aided response and recovery and informed decision-makers. We mapped 4312 coseismic and postseismic landslides. We also surveyed 491 glacier lakes for earthquake damage but found only nine landslide-impacted lakes and no visible satellite evidence of outbursts. Landslide densities correlate with slope, peak ground acceleration, surface downdrop, and specific metamorphic lithologies and large plutonic intrusions.

  16. Geomorphic and Geologic Controls of Geohazards induced by Nepal's 2015 Gorkha Earthquake

    Science.gov (United States)

    Kargel, J. S.; Leonard, G. J.; Shugar, D. H.; Haritashya, U.K.; Bevington, A.; Fielding, E. J.; Fujita, K.; Geertsema, M.; Miles, E. S.; Steiner, J.; hide

    2015-01-01

    The Gorkha earthquake (Magnitude 7.8) on 25 April 2015 and later aftershocks struck South Asia, killing approx.9,000 and damaging a large region. Supported by a large campaign of responsive satellite data acquisitions over the earthquake disaster zone, our team undertook a satellite image survey of the earthquakes induced geohazards in Nepal and China and an assessment of the geomorphic, tectonic, and lithologic controls on quake-induced landslides. Timely analysis and communication aided response and recovery and informed decision makers. We mapped 4,312 co-seismic and post-seismic landslides. We also surveyed 491 glacier lakes for earthquake damage, but found only 9 landslide-impacted lakes and no visible satellite evidence of outbursts. Landslide densities correlate with slope, peak ground acceleration, surface downdrop, and specific metamorphic lithologies and large plutonic intrusions.

  17. Dissecting the roles of ROCK isoforms in stress-induced cell detachment

    OpenAIRE

    Shi, Jianjian; Surma, Michelle; Zhang, Lumin; Wei, Lei

    2013-01-01

    The homologous Rho kinases, ROCK1 and ROCK2, are involved in stress fiber assembly and cell adhesion and are assumed to be functionally redundant. Using mouse embryonic fibroblasts (MEFs) derived from ROCK1 −/− and ROCK2−/− mice, we have recently reported that they play different roles in regulating doxorubicin-induced stress fiber disassembly and cell detachment: ROCK1 is involved in destabilizing the actin cytoskeleton and cell detachment, whereas ROCK2 is required for stabilizing the actin...

  18. Evaluation of excavation-induced changes in rock permeability

    Energy Technology Data Exchange (ETDEWEB)

    Kelsall, P.C.; Case, J.B.; Chabannes, C.R.

    1984-06-01

    The nature of the changes in permeability around an underground opening induced by blast-damage or stress-relief is an important factor in the design of nuclear waste repositories in rocks such as granite or basalt. Changes in stress and corresponding changes in rock mass hydraulic conductivity are analyzed for a circular shaft using simplifying assumptions regarding fracture geometry and initial stress state. Stress distributions around the shaft are calculated using closed-form solutions and are related to changes in hydraulic conductivity using a form of the cubic law for flow through fractured media. The analysis predicts that hydraulic conductivity may be increased, close to the wall of the opening, by two to three orders of magnitude over the far-field value solely in response to stress relief. The zone in which hydraulic conductivity is increased by at least one order of magnitude over the far-field value is limited to within one to two radii from the opening. Blasting may result in large increases in hydraulic conductivity immediately adjacent to an opening but blast damage may be limited to within 0.3 m of the opening using controlled blasting techniques with low perimeter charge weights. 44 references.

  19. Earthquake Damage - General

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An earthquake is the motion or trembling of the ground produced by sudden displacement of rock in the Earth's crust. Earthquakes result from crustal strain,...

  20. Clustering of induced earthquakes in Oklahoma and the relation to subsurface geologic features

    Science.gov (United States)

    Shah, A. K.; Keller, G. R., Jr.

    2015-12-01

    Recent research shows that a significant amount of seismic activity in Oklahoma since 2009 is likely related to fluid injection. Seismicity has been observed to generally increase in areas where injection volume and rates are highest but there is a significant amount of variation, with nearby areas experiencing notably different amounts of seismicity. Likely contributors to these differences are the presence of optimally oriented faults and differences in rock permeability structure since rocks with higher permeability are more likely to experience pore fluid pressure changes that can bring faults closer to failure. Most earthquakes occur at depths of ~4-8 km, within crystalline rock of the mid-Proterozoic western granite-rhyolite terrane. Within this terrane, drill-hole data show instances of mafic intrusive rocks that may in part be related to the mid-continent rift. To better understand relations between subsurface geology and seismicity, we reprocessed 1970's NURE airborne magnetic data. The 5-8-km line spacing of the surveys is coarse, but the processed data show subtle, ~20-35-km long lineaments trending mostly NNW but also NW and NE. Some of these correspond to mapped faults; others are interpreted to represent faults or folds. In some areas the lineaments correspond to earthquake locations, but the magnetic data are often too coarse to establish a clear correspondence. The magnetic maps also show rounded highs that are located near sites where drilling has encountered mafic rock, strongly suggesting that the highs represent mafic intrusions. We find that many earthquakes cluster around or near the edges of the magnetic highs but much less frequently over them, even when they are located close to high-volume injection wells. We hypothesize that the rounded magnetic highs represent mafic intrusions with decreased permeability. In contrast, contacts at the edges of these intrusions may have higher permeability and are thus more likely to experience seismicity.

  1. Rock fracture grouting with microbially induced carbonate precipitation

    Science.gov (United States)

    Minto, James M.; MacLachlan, Erica; El Mountassir, Gráinne; Lunn, Rebecca J.

    2016-11-01

    Microbially induced carbonate precipitation has been proposed for soil stabilization, soil strengthening, and permeability reduction as an alternative to traditional cement and chemical grouts. In this paper, we evaluate the grouting of fine aperture rock fractures with calcium carbonate, precipitated through urea hydrolysis, by the bacteria Sporosarcina pasteurii. Calcium carbonate was precipitated within a small-scale and a near field-scale (3.1 m2) artificial fracture consisting of a rough rock lower surfaces and clear polycarbonate upper surfaces. The spatial distribution of the calcium carbonate precipitation was imaged using time-lapse photography and the influence on flow pathways revealed from tracer transport imaging. In the large-scale experiment, hydraulic aperture was reduced from 276 to 22 μm, corresponding to a transmissivity reduction of 1.71 × 10-5 to 8.75 × 10-9 m2/s, over a period of 12 days under constantly flowing conditions. With a modified injection strategy a similar three orders of magnitude reduction in transmissivity was achieved over a period of 3 days. Calcium carbonate precipitated over the entire artificial fracture with strong adhesion to both upper and lower surfaces and precipitation was controlled to prevent clogging of the injection well by manipulating the injection fluid velocity. These experiments demonstrate that microbially induced carbonate precipitation can successfully be used to grout a fracture under constantly flowing conditions and may be a viable alternative to cement based grouts when a high level of hydraulic sealing is required and chemical grouts when a more durable grout is required.

  2. Fracking, wastewater disposal, and earthquakes

    Science.gov (United States)

    McGarr, Arthur

    2016-03-01

    In the modern oil and gas industry, fracking of low-permeability reservoirs has resulted in a considerable increase in the production of oil and natural gas, but these fluid-injection activities also can induce earthquakes. Earthquakes induced by fracking are an inevitable consequence of the injection of fluid at high pressure, where the intent is to enhance permeability by creating a system of cracks and fissures that allow hydrocarbons to flow to the borehole. The micro-earthquakes induced during these highly-controlled procedures are generally much too small to be felt at the surface; indeed, the creation or reactivation of a large fault would be contrary to the goal of enhancing permeability evenly throughout the formation. Accordingly, the few case histories for which fracking has resulted in felt earthquakes have been due to unintended fault reactivation. Of greater consequence for inducing earthquakes, modern techniques for producing hydrocarbons, including fracking, have resulted in considerable quantities of coproduced wastewater, primarily formation brines. This wastewater is commonly disposed by injection into deep aquifers having high permeability and porosity. As reported in many case histories, pore pressure increases due to wastewater injection were channeled from the target aquifers into fault zones that were, in effect, lubricated, resulting in earthquake slip. These fault zones are often located in the brittle crystalline rocks in the basement. Magnitudes of earthquakes induced by wastewater disposal often exceed 4, the threshold for structural damage. Even though only a small fraction of disposal wells induce earthquakes large enough to be of concern to the public, there are so many of these wells that this source of seismicity contributes significantly to the seismic hazard in the United States, especially east of the Rocky Mountains where standards of building construction are generally not designed to resist shaking from large earthquakes.

  3. Maximum Magnitude and Probabilities of Induced Earthquakes in California Geothermal Fields: Applications for a Science-Based Decision Framework

    Science.gov (United States)

    Weiser, Deborah Anne

    Induced seismicity is occurring at increasing rates around the country. Brodsky and Lajoie (2013) and others have recognized anthropogenic quakes at a few geothermal fields in California. I use three techniques to assess if there are induced earthquakes in California geothermal fields; there are three sites with clear induced seismicity: Brawley, The Geysers, and Salton Sea. Moderate to strong evidence is found at Casa Diablo, Coso, East Mesa, and Susanville. Little to no evidence is found for Heber and Wendel. I develop a set of tools to reduce or cope with the risk imposed by these earthquakes, and also to address uncertainties through simulations. I test if an earthquake catalog may be bounded by an upper magnitude limit. I address whether the earthquake record during pumping time is consistent with the past earthquake record, or if injection can explain all or some of the earthquakes. I also present ways to assess the probability of future earthquake occurrence based on past records. I summarize current legislation for eight states where induced earthquakes are of concern. Unlike tectonic earthquakes, the hazard from induced earthquakes has the potential to be modified. I discuss direct and indirect mitigation practices. I present a framework with scientific and communication techniques for assessing uncertainty, ultimately allowing more informed decisions to be made.

  4. RhoA/rock signaling mediates peroxynitrite-induced functional impairment of Rat coronary vessels.

    Science.gov (United States)

    Sun, Zhijun; Wu, Xing; Li, Weiping; Peng, Hui; Shen, Xuhua; Ma, Lu; Liu, Huirong; Li, Hongwei

    2016-10-11

    Diabetes-induced vascular dysfunction may arise from reduced nitric oxide (NO) availability, following interaction with superoxide to form peroxynitrite. Peroxynitrite can induce formation of 3-nitrotyrosine-modified proteins. RhoA/ROCK signaling is also involved in diabetes-induced vascular dysfunction. The study aimed to investigate possible links between Rho/ROCK signaling, hyperglycemia, and peroxynitrite in small coronary arteries. Rat small coronary arteries were exposed to normal (NG; 5.5 mM) or high (HG; 23 mM) D-glucose. Vascular ring constriction to 3 mM 4-aminopyridine and dilation to 1 μM forskolin were measured. Protein expression (immunohistochemistry and western blot), mRNA expression (real-time PCR), and protein activity (luminescence-based G-LISA and kinase activity spectroscopy assays) of RhoA, ROCK1, and ROCK2 were determined. Vascular ring constriction and dilation were smaller in the HG group than in the NG group (P ROCK partially reversed the effects of HG. Peroxynitrite impaired vascular ring constriction/dilation; this was partially reversed by inhibition of RhoA or ROCK. Protein and mRNA expressions of RhoA, ROCK1, and ROCK2 were higher under HG than NG (P ROCK (P ROCK1, and ROCK2 activity (P ROCK1, and ROCK2 activity; these actions were partially inhibited by 100 μM urate (peroxynitrite scavenger). Exogenous peroxynitrite had no effect on the expression of the voltage-dependent K(+) channels 1.2 and 1.5. Peroxynitrite-induced coronary vascular dysfunction may be mediated, at least in part, through increased expressions and activities of RhoA, ROCK1, and ROCK2.

  5. Earthquake-induced ground failures in Italy from a reviewed database

    Science.gov (United States)

    Martino, S.; Prestininzi, A.; Romeo, R. W.

    2014-04-01

    A database (Italian acronym CEDIT) of earthquake-induced ground failures in Italy is presented, and the related content is analysed. The catalogue collects data regarding landslides, liquefaction, ground cracks, surface faulting and ground changes triggered by earthquakes of Mercalli epicentral intensity 8 or greater that occurred in the last millennium in Italy. As of January 2013, the CEDIT database has been available online for public use (ceri.uniroma1.it/cn/gis.jsp"_target="blank">http://www.ceri.uniroma1.it/cn/gis.jsp ) and is presently hosted by the website of the Research Centre for Geological Risks (CERI) of the Sapienza University of Rome. Summary statistics of the database content indicate that 14% of the Italian municipalities have experienced at least one earthquake-induced ground failure and that landslides are the most common ground effects (approximately 45%), followed by ground cracks (32%) and liquefaction (18%). The relationships between ground effects and earthquake parameters such as seismic source energy (earthquake magnitude and epicentral intensity), local conditions (site intensity) and source-to-site distances are also analysed. The analysis indicates that liquefaction, surface faulting and ground changes are much more dependent on the earthquake source energy (i.e. magnitude) than landslides and ground cracks. In contrast, the latter effects are triggered at lower site intensities and greater epicentral distances than the other environmental effects.

  6. Measuring the size of mining-induced earthquakes: a proposal

    CSIR Research Space (South Africa)

    Ebrahim-Trollope, R

    2013-10-01

    Full Text Available Seismology. Academic Press, New York Gutenberg, B. and Richter C.F. (1956). Magnitude and energy of earthquakes, Annali di geofisica, IX, pp. 1 - 15. Hanks, T.C. and Kanamori, H., (1970). A moment magnitude scale, J Geophys. Res., 84, 2348...

  7. Anomalous Seismic Velocity Drop in Iron and Biotite Rich Amphibolite to Granulite Facies Transitional Rocks from Deccan Volcanic Covered 1993 Killari Earthquake Region, Maharashtra (India): a Case Study

    Science.gov (United States)

    Pandey, O. P.; Tripathi, Priyanka; Vedanti, Nimisha; Srinivasa Sarma, D.

    2016-07-01

    65 Ma Deccan Volcanic Province of western India forms one of the largest flood basaltic eruptions on the surface of the earth. The nature of the concealed crust below this earthquake prone region, which is marked by several low velocity zones at different depths has hardly been understood. These low velocity zones have been invariably interpreted as fluid-filled zones, genetically connected to earthquake nucleation. While carrying out detailed geological and petrophysical studies on the Late Archean basement cores, obtained from a 617 m deep KLR-1 borehole, drilled in the epicentral zone of 1993 Killari earthquake region of the southern Deccan Volcanic Province, we came across several instances where we observed remarkable drop in measured P-wave velocity in a number of high density cores. We provide detailed petrographic and geological data on 11 such anomalous samples which belong to mid-crustal amphibolite to granulite facies transitional rocks. They are associated with a mean P-wave velocity of 6.02 km/s (range 5.82-6.22 km/s) conforming to granitic upper crust, but in contrast have a high mean density of 2.91 g/cm3 (range 2.75-3.08 g/cm3), which characterise mid to lower crust. This velocity drop, which is as much as 15 % in some cores, is primarily attributed to FeOT enrichment (up to about 23 wt%) during the course of mantle-fluid driven retrogressive metasomatic reactions, caused by exhumation of deep-seated mafic rocks. Presence of Iron content (mainly magnetite), widely seen as opaques in thin sections of the rocks, seems to have resulted into sharp increase in density, as well as mean atomic weight. Our study indicates that the measured V p is inversely related to FeOT content as well as mean atomic weight of the rock.

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

    Science.gov (United States)

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

    2016-04-01

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

  9. Dissecting the roles of ROCK isoforms in stress-induced cell detachment.

    Science.gov (United States)

    Shi, Jianjian; Surma, Michelle; Zhang, Lumin; Wei, Lei

    2013-05-15

    The homologous Rho kinases, ROCK1 and ROCK2, are involved in stress fiber assembly and cell adhesion and are assumed to be functionally redundant. Using mouse embryonic fibroblasts (MEFs) derived from ROCK1(-/-) and ROCK2(-/-) mice, we have recently reported that they play different roles in regulating doxorubicin-induced stress fiber disassembly and cell detachment: ROCK1 is involved in destabilizing the actin cytoskeleton and cell detachment, whereas ROCK2 is required for stabilizing the actin cytoskeleton and cell adhesion. Here, we present additional insights into the roles of ROCK1 and ROCK2 in regulating stress-induced impairment of cell-matrix and cell-cell adhesion. In response to doxorubicin, ROCK1(-/-) MEFs showed significant preservation of both focal adhesions and adherens junctions, while ROCK2(-/-) MEFs exhibited impaired focal adhesions but preserved adherens junctions compared with the wild-type MEFs. Additionally, inhibition of focal adhesion or adherens junction formations by chemical inhibitors abolished the anti-detachment effects of ROCK1 deletion. Finally, ROCK1(-/-) MEFs, but not ROCK2(-/-) MEFs, also exhibited preserved central stress fibers and reduced cell detachment in response to serum starvation. These results add new insights into a novel mechanism underlying the anti-detachment effects of ROCK1 deletion mediated by reduced peripheral actomyosin contraction and increased actin stabilization to promote cell-cell and cell-matrix adhesion. Our studies further support the differential roles of ROCK isoforms in regulating stress-induced loss of central stress fibers and focal adhesions as well as cell detachment.

  10. Earthquake-induced Landslides and Quake Lakes during the great Sichuan Earthquake of May 12, 2008 (Sichuan, China)

    Science.gov (United States)

    Lekkas, E.

    2009-04-01

    The Mw 8.0 R earthquake on the 12th of May 2008 that stroke the Sichuan Prefecture of the People's Republic of China caused tenths of thousands of casualties and significant social and economic consequences. The earthquake was triggered by a reverse fault approximately 100 km in length, of NE-SW strike, dipping towards the NW with a reverse-lateral slip character and focal depth of 18 Km. Due to the great height and steepness of the slopes and their loose geotechnical characteristics in the mountainous terrain, thousands of landslides and collapses occurred in the Longmenshan fault zone during the earthquake, resulting in a large amount of geotechnical damages, such as the destruction the roads, villages, towns and bridges. A total of more than 9000 geological disasters occurred, among which there were approximately 4000 landslides, 2300 slop collapses, 800 debris flows, 1700 unstable slopes and more than 80 locations with hidden danger of geological hazard. Approximately 1.000.000 people and their properties in the affected area were under a directly serious threat. Landslides mobilized millions of cubic meters of rock and soil that slid across adjacent rivers, creating large landslide dams. The blockage of rivers was accompanied by the formation of quake lakes that were flooding the upstream river valleys. As water rises, there is potential of overtopping and downstream flooding. In the affected area 32 quake lakes were formed of various scales. Τhe largest one , and most dangerous, is located in Beichuan County. The lake was formed because massive landslide partially blocked Qianjiang River upstream of the devastated Beichuan County seat. It is 40 m deep and contains about 30-40 million m3 of water. The landslide dam had a height of 60 m, the quake lake in the Shitingjiang River direction is more than 900 m long, its largest width is more than 600 m, and its area at the dam crest level is about 300.000 m2. As of June 7, 2008 the reservoir capacity of the quake

  11. Numerical Modeling of Earthquake-Induced Landslide Using an Improved Discontinuous Deformation Analysis Considering Dynamic Friction Degradation of Joints

    Science.gov (United States)

    Huang, Da; Song, Yixiang; Cen, Duofeng; Fu, Guoyang

    2016-12-01

    Discontinuous deformation analysis (DDA) as an efficient technique has been extensively applied in the dynamic simulation of discontinuous rock mass. In the original DDA (ODDA), the Mohr-Coulomb failure criterion is employed as the judgment principle of failure between contact blocks, and the friction coefficient is assumed to be constant in the whole calculation process. However, it has been confirmed by a host of shear tests that the dynamic friction of rock joints degrades. Therefore, the friction coefficient should be gradually reduced during the numerical simulation of an earthquake-induced rockslide. In this paper, based on the experimental results of cyclic shear tests on limestone joints, exponential regression formulas are fitted for dynamic friction degradation, which is a function of the relative velocity, the amplitude of cyclic shear displacement and the number of its cycles between blocks with an edge-to-edge contact. Then, an improved DDA (IDDA) is developed by implementing the fitting regression formulas and a modified removing technique of joint cohesion, in which the cohesion is removed once the `sliding' or `open' state between blocks appears for the first time, into the ODDA. The IDDA is first validated by comparing with the theoretical solutions of the kinematic behaviors of a sliding block on an inclined plane under dynamic loading. Then, the program is applied to model the Donghekou landslide triggered by the 2008 Wenchuan earthquake in China. The simulation results demonstrate that the dynamic friction degradation of joints has great influences on the runout and velocity of sliding mass. Moreover, the friction coefficient possesses higher impact than the cohesion of joints on the kinematic behaviors of the sliding mass.

  12. Geomorphic and geologic controls of geohazards induced by Nepal’s 2015 Gorkha earthquake

    Science.gov (United States)

    Kargel, J.S.; Leonard, G.J.; Shugar, D. H.; Haritashya, U. K.; Bevington, A.; Fielding, E.J.; Fujita, K.; Geertsema, M.; Miles, E. S.; Steiner, J.; Anderson, E.; Bajracharya, S.; Bawden, G.W.; Breashears, D. F.; Byers, A.; Collins, B.; Dhital, M. R.; Donnellan, A.; Evans, T. L.; Geai, M. L.; Glasscoe, M. T.; Green, D.; Gurung, D. R.; Heijenk, R.; Hilborn, A.; Hudnut, K.; Huyck, C.; Immerzeel, W. W.; Liming, Jiang; Jibson, R.; Kaab, A.; Khanal, N. R.; Kirschbaum, D.; Kraaijenbrink, P. D. A.; Lamsal, D.; Shiyin, Liu; Mingyang, Lv; McKinney, D.; Nahirnick, N. K.; Zhuotong, Nan; Ojha, S.; Olsenholler, J.; Painter, T.H.; Pleasants, M.; Pratima, K. C.; Yuan, Q. I.; Raup, B.H.; Regmi, D.; Rounce, D. R.; Sakai, A.; Donghui, Shangguan; Shea, J. M.; Shrestha, A. B.; Shukla, A.; Stumm, D.; van der Kooij, M.; Voss, K.; Xin, Wang; Weihs, B.; Lizong, Wu; Xiaojun, Yao; Yoder, M. R.; Young, N.

    2016-01-01

    The Gorkha earthquake (magnitude 7.8) on 25 April 2015 and later aftershocks struck South Asia, killing ~9000 people and damaging a large region. Supported by a large campaign of responsive satellite data acquisitions over the earthquake disaster zone, our team undertook a satellite image survey of the earthquakes’ induced geohazards in Nepal and China and an assessment of the geomorphic, tectonic, and lithologic controls on quake-induced landslides. Timely analysis and communication aided response and recovery and informed decision-makers. We mapped 4312 coseismic and postseismic landslides. We also surveyed 491 glacier lakes for earthquake damage but found only nine landslide-impacted lakes and no visible satellite evidence of outbursts. Landslide densities correlate with slope, peak ground acceleration, surface downdrop, and specific metamorphic lithologies and large plutonic intrusions.

  13. Seismological and geodetic constraints on the 2011 Mw5.3 Trinidad, Colorado earthquake and induced deformation in the Raton Basin

    Science.gov (United States)

    Barnhart, W. D.; Benz, H. M.; Hayes, G. P.; Rubinstein, J. L.; Bergman, E.

    2014-10-01

    The Raton Basin of southern Colorado and northern New Mexico is an actively produced hydrocarbon basin that has experienced increased seismicity since 2001, including the August 2011 Mw5.3 Trinidad normal faulting event. Following the 2011 earthquake, regional seismic observations were used to relocate 21 events, including the 2011 main shock, two foreshocks, and 13 aftershocks. Additionally, interferometric synthetic aperture radar (InSAR) observations of both the 2011 event and preevent basin deformation place constraint on the spatial kinematics of the 2011 event and localized basin subsidence due to ground water or gas withdrawal. We find that the 2011 earthquake ruptured an 8-10 km long segment of a normal fault at depths of 1.5-6.0 km within the crystalline Precambrian basement underlying the Raton Basin sedimentary rocks. The earthquake also nucleated within the crystalline basement in the vicinity of an active wastewater disposal site. The ensuing aftershock sequence demonstrated statistical properties expected for intraplate earthquakes, though the length of the 2011 earthquake is unexpectedly long for an Mw5.3 event, suggesting that wastewater disposal may have triggered a low stress drop, otherwise natural earthquake. Additionally, preevent and postevent seismicity in the Raton Basin spatially correlates to regions of subsidence observed in InSAR time series analysis. While these observations cannot discern a causal link between hydrocarbon production and seismicity, they constrain spatial relationships between active basin deformation and geological and anthropogenic features. Furthermore, the InSAR observations highlight the utility of space-based geodetic observations for monitoring and assessing anthropogenically induced and triggered deformation.

  14. Earthquake-induced soft-sediment deformations and seismically amplified erosion rates recorded in varved sediments of Köyceğiz Lake (SW Turkey)

    KAUST Repository

    Avsar, Ulas

    2016-06-06

    Earthquake-triggered landslides amplify erosion rates in catchments, i.e. catchment response to seismic shocks (CR). In addition to historical eyewitness accounts of muddy rivers implying CRs after large earthquakes, several studies have quantitatively reported increased sediment concentrations in rivers after earthquakes. However, only a few paleolimnological studies could detect CRs within lacustrine sedimentary sequences as siliciclastic-enriched intercalations within background sedimentation. Since siliciclastic-enriched intercalations can easily be of non-seismic origin, their temporal correlation with nearby earthquakes is crucial to assign a seismic triggering mechanism. In most cases, either uncertainties in dating methods or the lack of recent seismic activity has prevented reliable temporal correlations, making the seismic origin of observed sedimentary events questionable. Here, we attempt to remove this question mark by presenting sedimentary traces of CRs in the 370-year-long varved sequence of Köyceğiz Lake (SW Turkey) that we compare with estimated peak ground acceleration (PGA) values of several nearby earthquakes. We find that earthquakes exceeding estimated PGA values of ca. 20 cm/s2 can induce soft-sediment deformations (SSD), while CRs seem only to be triggered by PGA levels higher than 70 cm/s2. In Köyceğiz Lake, CRs produce Cr- and Ni-enriched sedimentation due to the seismically mobilized soils derived from ultramafic rocks in the catchment. Given the varve chronology, the residence time of the seismically mobilized material in the catchment is determined to be 5 to 10 years.

  15. Some Factors Controlling the Seismic Hazard due to Earthquakes Induced by Fluid Injection at Depth

    Science.gov (United States)

    McGarr, A.

    2012-12-01

    The maximum seismic moment (or moment magnitude) is an important measure of the seismic hazard associated with earthquakes induced by deep fluid injection. Although it would be advantageous to be able to predict the induced earthquake outcome, including the maximum seismic moment, of a specified fluid injection project in advance, this capability has, to date, proved to be elusive because the geomechanical and hydrological factors that control the seismic response to injection are too poorly understood. Fortunately, the vast majority of activities involving the injection of fluids into deep aquifers do not cause earthquakes that are large enough to be of any consequence. There have been, however, significant exceptions during the past 50 years, starting with the earthquakes induced by injection of wastewater at the Rocky Mountain Arsenal Well, during the 1960s, that caused extensive damage in the Denver, CO, area. Results from numerous case histories of earthquakes induced by injection activities, including wastewater disposal at depth and the development of enhanced geothermal systems, suggest that it may be feasible to estimate bounds on maximum magnitudes based on the volume of injected liquid. For these cases, volumes of injected liquid ranged from approximately 11.5 thousand to 5 million cubic meters and resulted in main shock moment magnitudes from 3.4 to 5.3. Because the maximum seismic moment appears to be linearly proportional to the total volume of injected fluid, this upper bound is expected to increase with time as long as a given injection well remains active. For example, in the Raton Basin, southern Colorado and northern New Mexico, natural gas is produced from an extensive coal bed methane field. The deep injection of wastewater associated with this gas production has induced a sequence of earthquakes starting in August 2001, shortly after the beginning of major injection activities. Most of this seismicity defines a northeast striking plane dipping

  16. Psychology of earthquake-induced stress cardiomyopathy, myocardial infarction and non-cardiac chest pain.

    Science.gov (United States)

    Zarifeh, J A; Mulder, R T; Kerr, A J; Chan, C W; Bridgman, P G

    2012-04-01

    To compare psychological factors in patients presenting to hospital with earthquake-induced stress cardiomyopathy, myocardial infarction (MI) and non-cardiac chest pain. We hypothesised that patients with stress cardiomyopathy and non-cardiac chest pain would be more psychologically vulnerable than those with MI. Cardiology admitting staff in the week following the September 2010 Christchurch earthquake prospectively identified patients with earthquake-precipitated chest pain. Males were excluded. All consenting women met diagnostic criteria for one of the three conditions. Patients underwent a semistructured interview with a senior clinical psychologist who was blind to the cardiac diagnosis. Premorbid psychological factors, experience of the earthquake and psychological response were assessed using a range of validated tools. Seventeen women were included in the study, six with stress cardiomyopathy, five with MI and six with non-cardiac chest pain. Earthquake experiences were notably similar across the groups. Patients with non-cardiac chest pain scored high on the hospital anxiety and depression scale, the health anxiety questionnaire, the Eysenck neuroticism scale and the Impact of Event scale. Women with stress cardiomyopathy scored as the most psychologically robust. Depression and extroversion scores were the same across groups. Our hypothesis was incorrect. Women with non-cardiac chest pain following an earthquake have higher anxiety and neuroticism scores than women with either MI or stress cardiomyopathy. Stress cardiomyopathy following an earthquake is not specific to psychologically vulnerable women. The psychology of natural disaster-induced stress cardiomyopathy may differ from that of sporadic cases. © 2012 The Authors. Internal Medicine Journal © 2012 Royal Australasian College of Physicians.

  17. ROCK1 isoform-specific deletion reveals a role for diet-induced insulin resistance

    Science.gov (United States)

    Lee, Seung-Hwan; Huang, Hu; Choi, Kangduk; Lee, Dae Ho; Shi, Jianjian; Liu, Tiemin; Chun, Kwang Hoon; Seo, Ji A.; Lima, Ines S.; Zabolotny, Janice M.; Wei, Lei

    2013-01-01

    Rho kinase (ROCK) isoforms regulate insulin signaling and glucose metabolism negatively or positively in cultured cell lines and skeletal muscle. However, the in vivo function of the ROCK1 isoform in adipose tissue has not been addressed. To determine the specific role of the adipose ROCK1 isoform in the development of insulin resistance and obesity, mice lacking ROCK1 in adipose tissue globally or selectively were studied. Here, we show that insulin's ability to activate IRS-1/PI3K/Akt signaling was greatly enhanced in adipose tissue of ROCK1−/− mice compared with wild-type mice. These effects resulted from the inhibitory effect of ROCK1 on insulin receptor action, as evidenced by the fact that IR tyrosine phosphorylation was abolished in ROCK1−/− MEF cells when ROCK1 was reexpressed. Consistently, adipose-specific disruption of ROCK1 increased IR tyrosine phosphorylation in adipose tissue and modestly improved sensitivity to insulin in obese mice induced by high-fat feeding. This effect is independent of any changes in adiposity, number or size of adipocytes, and metabolic parameters, including glucose, insulin, leptin, and triglyceride levels, demonstrating a minimal effect of adipose ROCK1 on whole body metabolism. Enzymatic activity of ROCK1 in adipose tissue remained ∼50%, which likely originated from the fraction of stromal vascular cells, suggesting involvement of these cells for adipose metabolic regulation. Moreover, ROCK isoform activities were increased in adipose tissue of diet-induced or genetically obese mice. These data suggest that adipose ROCK1 isoform plays an inhibtory role for the regulation of insulin sensitivity in diet-induced obesity in vivo. PMID:24326423

  18. Revisit the classical Newmark displacement method for earthquake-induced wedge slide

    Science.gov (United States)

    Yang, Che-Ming; Cheng, Hui-Yun; Wu, Wen-Jie; Hsu, Chang-Hsuan; Dong, Jia-Jyun; Lee, Chyi-Tyi

    2016-04-01

    Newmark displacement method has been widely used to study the earthquake-induced landslides and adopted to explore the initiation and kinematics of catastrophic planar failure in recent years. However, surprisingly few researchers utilize the Newmark displacement method to study the earthquake-induced wedge slide. The classical Newmark displacement method for earthquake-induced wedge sliding assumed the wedge is rigid and the vertical acceleration, as well as the horizontal acceleration perpendicular to the sliding direction, is neglected. Moreover, the friction coefficients on the weak planes are assumed as unchanged during sliding. The purpose of this study is to test the reasonableness of the aforementioned assumptions. This study uses Newmark displacement method incorporating the rigid wedge method (RWM) and maximum shear stress method (MSSM) to evaluate the influence of wedge deformation. We design the geometry of the wedge and input the synthetic seismicity to trigger the wedge slide. The influence for neglecting the vertical and horizontal (perpendicular to the sliding direction) accelerations is also assessed. Besides, this research incorporates the velocity-displacement dependent friction law in the analysis to evaluate the influence of constant friction coefficient assumption. Result of this study illustrated that the aforementioned assumptions have significant effects on the calculated permeant displacement, moving speed, and failure initiation. To conclude, this study provides new insights on the initiation and kinematics of an earthquake induced wedge slide.

  19. Body-wave seismic interferometry applied to earthquake- and storm-induced wavefield

    NARCIS (Netherlands)

    Ruigrok, E.N.

    2012-01-01

    Seismology is the study of the vibration of the Earth. Seismologists pay much attention to the main source of Earth vibration: earthquakes. But also other seismic sources, like mining blasts, ocean storms and windmills, are studied. All these sources induce seismic waves, which can eventually be rec

  20. Body-wave seismic interferometry applied to earthquake- and storm-induced wavefield

    NARCIS (Netherlands)

    Ruigrok, E.N.

    2012-01-01

    Seismology is the study of the vibration of the Earth. Seismologists pay much attention to the main source of Earth vibration: earthquakes. But also other seismic sources, like mining blasts, ocean storms and windmills, are studied. All these sources induce seismic waves, which can eventually be

  1. 2016 one-year seismic hazard forecast for the Central and Eastern United States from induced and natural earthquakes

    Science.gov (United States)

    Petersen, Mark D.; Mueller, Charles S.; Moschetti, Morgan P.; Hoover, Susan M.; Llenos, Andrea L.; Ellsworth, William L.; Michael, Andrew J.; Rubinstein, Justin L.; McGarr, Arthur F.; Rukstales, Kenneth S.

    2016-03-28

    The U.S. Geological Survey (USGS) has produced a 1-year seismic hazard forecast for 2016 for the Central and Eastern United States (CEUS) that includes contributions from both induced and natural earthquakes. The model assumes that earthquake rates calculated from several different time windows will remain relatively stationary and can be used to forecast earthquake hazard and damage intensity for the year 2016. This assessment is the first step in developing an operational earthquake forecast for the CEUS, and the analysis could be revised with updated seismicity and model parameters. Consensus input models consider alternative earthquake catalog durations, smoothing parameters, maximum magnitudes, and ground motion estimates, and represent uncertainties in earthquake occurrence and diversity of opinion in the science community. Ground shaking seismic hazard for 1-percent probability of exceedance in 1 year reaches 0.6 g (as a fraction of standard gravity [g]) in northern Oklahoma and southern Kansas, and about 0.2 g in the Raton Basin of Colorado and New Mexico, in central Arkansas, and in north-central Texas near Dallas. Near some areas of active induced earthquakes, hazard is higher than in the 2014 USGS National Seismic Hazard Model (NHSM) by more than a factor of 3; the 2014 NHSM did not consider induced earthquakes. In some areas, previously observed induced earthquakes have stopped, so the seismic hazard reverts back to the 2014 NSHM. Increased seismic activity, whether defined as induced or natural, produces high hazard. Conversion of ground shaking to seismic intensity indicates that some places in Oklahoma, Kansas, Colorado, New Mexico, Texas, and Arkansas may experience damage if the induced seismicity continues unabated. The chance of having Modified Mercalli Intensity (MMI) VI or greater (damaging earthquake shaking) is 5–12 percent per year in north-central Oklahoma and southern Kansas, similar to the chance of damage caused by natural earthquakes

  2. Characterizing potentially induced earthquake rate changes in the Brawley Seismic Zone, southern California

    Science.gov (United States)

    Llenos, Andrea L.; Michael, Andrew J.

    2016-01-01

    The Brawley seismic zone (BSZ), in the Salton trough of southern California, has a history of earthquake swarms and geothermal energy exploitation. Some earthquake rate changes may have been induced by fluid extraction and injection activity at local geothermal fields, particularly at the North Brawley Geothermal Field (NBGF) and at the Salton Sea Geothermal Field (SSGF). We explore this issue by examining earthquake rate changes and interevent distance distributions in these fields. In Oklahoma and Arkansas, where considerable wastewater injection occurs, increases in background seismicity rate and aftershock productivity and decreases in interevent distance were indicative of fluid‐injection‐induced seismicity. Here, we test if similar changes occur that may be associated with fluid injection and extraction in geothermal areas. We use stochastic epidemic‐type aftershock sequence models to detect changes in the underlying seismogenic processes, shown by statistically significant changes in the model parameters. The most robust model changes in the SSGF roughly occur when large changes in net fluid production occur, but a similar correlation is not seen in the NBGF. Also, although both background seismicity rate and aftershock productivity increased for fluid‐injection‐induced earthquake rate changes in Oklahoma and Arkansas, the background rate increases significantly in the BSZ only, roughly corresponding with net fluid production rate increases. Moreover, in both fields the interevent spacing does not change significantly during active energy projects. This suggests that, although geothermal field activities in a tectonically active region may not significantly change the physics of earthquake interactions, earthquake rates may still be driven by fluid injection or extraction rates, particularly in the SSGF.

  3. Numerical modeling of glacial earthquakes induced by iceberg capsize

    Science.gov (United States)

    Sergeant, A.; Yastrebov, V.; Castelnau, O.; Mangeney, A.; Stutzmann, E.; Montagner, J. P.; Burton, J. C.

    2015-12-01

    Glacial earthquakes is a class of seismic events of magnitude up to 5, occurring primarily in Greenland, in the margins of large marine-terminated glaciers with near-grounded termini. They are caused by calving of cubic-kilometer scale unstable icebergs which penetrate the full-glacier thickness and, driven by the buoyancy forces, capsize against the calving front. These phenomena produce seismic energy including surface waves with dominant energy between 10-150 s of period whose seismogenic source is compatible with the contact force exerted on the terminus by the iceberg while it capsizes. A reverse motion and posterior rebound of the terminus have also been measured and associated with the fluctuation of this contact force. Using a finite element model of iceberg and glacier terminus coupled with simplified fluid-structure interaction model, we simulate calving and capsize of icebergs. Contact and frictional forces are measured on the terminus and compared with laboratory experiments. We also study the influence of various factors, such as iceberg geometry, calving style and terminus interface. Being extended to field environments, the simulation results are compared with forces obtained by seismic waveform inversion of registered glacial earthquakes.

  4. Influence of hydrodynamic parameters on tsunami run-up uncertainty induced by earthquake random slip distribtutions

    Science.gov (United States)

    Løvholt, Finn; Kim, Jihwan; Pedersen, Geir; Harbitz, Carl

    2016-04-01

    The standard approach in forward modeling of earthquake tsunamis usually assume a uniform slip pattern. This is assumption is used both in deterministic and probabilistic models. However, the slip distribution for an earthquake is subject to (aleatory) uncertainty, and consequently the induced tsunami run-up will have an uncertainty range even given the same moment magnitude and hypocentre earthquake location. Here, we present studies of run-up variability due to stochastic earthquake slip variation in both two and three dimensions. The approach taken is fully idealized, although we draw upon the experience from two of the most destructive events the last hundred years, namely the Mw8 1976 Moro Gulf earthquake and tsunami as well as the Mw9 2011 Tohoku earthquake tsunami. The former event is used to design the two-dimensional stochastic simulations, and the latter event the three-dimensional simulations. Our primary focus is not reproduce past run-up, but rather to investigate how the hydrodynamics influence uncertainty. These quantities include among others the non-hydrodynamic response during generation, frequency dispersion, friction from the seabed, and wave-breaking. We simulate tsunamis for an ensemble of synthetic random slip over an idealized shelf geometry broken into linear segments. The uncertainty propagation from source to run-up for the two different cases are discussed and compared. As demonstrated, both the dimensionality and the earthquake parameters influence the contributions of the hydrodynamic parameters on the uncertainty. Further work will be needed to explore the transitional behaviour between the two very different cases displayed here. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 603839 (Project ASTARTE).

  5. Source characteristics and geological implications of the January 2016 induced earthquake swarm near Crooked Lake, Alberta

    Science.gov (United States)

    Wang, Ruijia; Gu, Yu Jeffrey; Schultz, Ryan; Zhang, Miao; Kim, Ahyi

    2017-08-01

    On 2016 January 12, an intraplate earthquake with an initial reported local magnitude (ML) of 4.8 shook the town of Fox Creek, Alberta. While there were no reported damages, this earthquake was widely felt by the local residents and suspected to be induced by the nearby hydraulic-fracturing (HF) operations. In this study, we determine the earthquake source parameters using moment tensor inversions, and then detect and locate the associated swarm using a waveform cross-correlation based method. The broad-band seismic recordings from regional arrays suggest a moment magnitude (M) 4.1 for this event, which is the largest in Alberta in the past decade. Similar to other recent M ˜ 3 earthquakes near Fox Creek, the 2016 January 12 earthquake exhibits a dominant strike-slip (strike = 184°) mechanism with limited non-double-couple components (˜22 per cent). This resolved focal mechanism, which is also supported by forward modelling and P-wave first motion analysis, indicates an NE-SW oriented compressional axis consistent with the maximum compressive horizontal stress orientations delineated from borehole breakouts. Further detection analysis on industry-contributed recordings unveils 1108 smaller events within 3 km radius of the epicentre of the main event, showing a close spatial-temporal relation to a nearby HF well. The majority of the detected events are located above the basement, comparable to the injection depth (3.5 km) on the Duvernay shale Formation. The spatial distribution of this earthquake cluster further suggests that (1) the source of the sequence is an N-S-striking fault system and (2) these earthquakes were induced by an HF well close to but different from the well that triggered a previous (January 2015) earthquake swarm. Reactivation of pre-existing, N-S oriented faults analogous to the Pine Creek fault zone, which was reported by earlier studies of active source seismic and aeromagnetic data, are likely responsible for the occurrence of the January

  6. Numerical simulation study on hard-thick roof inducing rock burst in coal mine

    Institute of Scientific and Technical Information of China (English)

    何江; 窦林名; 牟宗龙; 曹安业; 巩思园

    2016-01-01

    In order to reveal the dynamic process of hard-thick roof inducing rock burst, one of the most common and strongest dynamic disasters in coal mine, the numerical simulation is conducted to study the dynamic loading effect of roof vibration on roadway surrounding rocks as well as the impact on stability. The results show that, on one hand, hard-thick roof will result in high stress concentration on mining surrounding rocks; on the other hand, the breaking of hard-thick roof will lead to mining seismicity, causing dynamic loading effect on coal and rock mass. High stress concentration and dynamic loading combination reaches to the mechanical conditions for the occurrence of rock burst, which will induce rock burst. The mining induced seismic events occurring in the roof breaking act on the mining surrounding rocks in the form of stress wave. The stress wave then has a reflection on the free surface of roadway and the tensile stress will be generated around the free surface. Horizontal vibration of roadway surrounding particles will cause instant changes of horizontal stress of roadway surrounding rocks; the horizontal displacement is directly related to the horizontal stress but is not significantly correlated with the vertical stress; the increase of horizontal stress of roadway near surface surrounding rocks and the release of elastic deformation energy of deep surrounding coal and rock mass are immanent causes that lead to the impact instability of roadway surrounding rocks. The most significant measures for rock burst prevention are controlling of horizontal stress and vibration strength.

  7. Induced polarization of volcanic rocks. 1Surface versus quadrature conductivity

    Science.gov (United States)

    Revil, A.; Breton, M. Le; Niu, Q.; Wallin, E.; Haskins, E.; Thomas, D. M.

    2016-11-01

    We performed complex conductivity measurements on 28 core samples from the hole drilled for the Humu´ula Groundwater Research Project (Hawai´i Island, HI, USA). The complex conductivity measurements were performed at 4 different pore water conductivities (0.07, 0.5, 1.0 or 2.0, and 10 S m-1 prepared with NaCl) over the frequency range 1 mHz to 45 kHz at 22 ± 1°C. The in-phase conductivity data are plotted against the pore water conductivity to determine, sample by sample, the intrinsic formation factor and the surface conductivity. The intrinsic formation factor is related to porosity by Archie's law with an average value of the cementation exponent m of 2.45, indicating that only a small fraction of the connected pore space controls the transport properties. Both the surface and quadrature conductivities are found to be linearly related to the cation exchange capacity of the material, which was measured with the cobalt hexamine chloride method. Surface and quadrature conductivities are found to be proportional to each other like for sedimentary siliclastic rocks. A Stern layer polarization model is used to explain these experimental results. Despite the fact that the samples contain some magnetite (up to 5% wt.), we were not able to identify the effect of this mineral on the complex conductivity spectra. These results are very encouraging in showing that galvanometric induced polarization measurements can be used in volcanic areas to separate the bulk from the surface conductivity and therefore to define some alteration attributes. Such a goal cannot be achieved with resistivity alone.

  8. Induced polarization of volcanic rocks - 1. Surface versus quadrature conductivity

    Science.gov (United States)

    Revil, A.; Le Breton, M.; Niu, Q.; Wallin, E.; Haskins, E.; Thomas, D. M.

    2017-02-01

    We performed complex conductivity measurements on 28 core samples from the hole drilled for the Humu'ula Groundwater Research Project (Hawai'i Island, HI, USA). The complex conductivity measurements were performed at 4 different pore water conductivities (0.07, 0.5, 1.0 or 2.0, and 10 S m-1 prepared with NaCl) over the frequency range 1 mHz to 45 kHz at 22 ± 1 °C. The in-phase conductivity data are plotted against the pore water conductivity to determine, sample by sample, the intrinsic formation factor and the surface conductivity. The intrinsic formation factor is related to porosity by Archie's law with an average value of the cementation exponent m of 2.45, indicating that only a small fraction of the connected pore space controls the transport properties. Both the surface and quadrature conductivities are found to be linearly related to the cation exchange capacity of the material, which was measured with the cobalt hexamine chloride method. Surface and quadrature conductivities are found to be proportional to each other like for sedimentary siliclastic rocks. A Stern layer polarization model is used to explain these experimental results. Despite the fact that the samples contain some magnetite (up to 5 per cent wt.), we were not able to identify the effect of this mineral on the complex conductivity spectra. These results are very encouraging in showing that galvanometric induced polarization measurements can be used in volcanic areas to separate the bulk from the surface conductivity and therefore to define some alteration attributes. Such a goal cannot be achieved with resistivity alone.

  9. Earthquake Science: a New Start

    Institute of Scientific and Technical Information of China (English)

    Chen Yun-tai

    2009-01-01

    @@ Understanding the mechanisms which cause earthquakes and thus earthquake prediction, is inher-ently difficult in comparison to other physical phenom-ena. This is due to the inaccessibility of the Earth's inte-rior, the infrequency of large earthquakes, and the com-plexities of the physical processes involved. Conse-quently, in its broadest sense, earthquake science--the science of studying earthquake phenomena, is a com-prehensive and inter-disciplinary field. The disciplines involved in earthquake science include: traditional seismology, earthquake geodesy, earthquake geology, rock mechanics, complex system theory, and informa-tion and communication technologies related to earth-quake studies.

  10. Correlation between hypocenter depth, antecedent precipitation and earthquake-induced landslide spatial distribution

    Science.gov (United States)

    Fukuoka, Hiroshi; Watanabe, Eisuke

    2017-04-01

    Since Keefer published the paper on earthquake magnitude and affected area, maximum epicentral/fault distance of induced landslide distribution in 1984, showing the envelope of plots, a lot of studies on this topic have been conducted. It has been generally supposed that landslides have been triggered by shallow quakes and more landslides are likely to occur with heavy rainfalls immediately before the quake. In order to confirm this, we have collected 22 case records of earthquake-induced landslide distribution in Japan and examined the effect of hypocenter depth and antecedent precipitation. Earthquake magnitude by JMA (Japan Meteorological Agency) of the cases are from 4.5 to 9.0. Analysis on hycpocenter depth showed the deeper quake cause wider distribution. Antecedent precipitation was evaluated using the Soil Water Index (SWI), which was developed by JMA for issuing landslide alert. We could not find meaningful correlation between SWI and the earthquake-induced landslide distribution. Additionally, we found that smaller minimum size of collected landslides results in wider distribution especially between 1,000 to 100,000 m2.

  11. Mining-induced earthquakes monitored during pit closure in the Midlothian Coalfield

    Energy Technology Data Exchange (ETDEWEB)

    Redmayne, D.W.; Richards, J.A.; Wild, P.W. [British Geological Survey, Edinburgh (United Kingdom). Global Seismology and Geomagnetism Group

    1998-06-01

    The British Geological Survey installed a seismometer network to monitor earthquakes around Rosslyn Chapel in the Midlothian Coalfield from November 1987 until January 1990. Accurate locations were obtained for 247 events and a close spatial and temporal association with concurrent coal mining, with a rapid decay of earthquake activity following pit closure, was demonstrated, indicating a mining-induced cause. Residual stress from past mining appears to have been an important factor in generating seismicity, and observations indicate that limiting the width of the workings or rate of extraction may significantly reduce or eliminate mining-induced earthquake activity. A frequency-magnitude analysis indicates a relatively high abundance of small events in this coalfield area. The maximum magnitude of a mining-induced earthquake likely to have been experienced during the life of the coalfield (maximum credible magnitude) was 3.0 M-L, although an extreme event (maximum possible magnitude) as large as 3.4 M-L was remotely possible. Significant seismic amplification was observed at Rosslyn Chapel, which is founded on sand and gravel, compared with a nearby bedrock site. As a consequence, relatively small magnitude events caused high, and occasionally damaging, seismic intensities at the chapel.

  12. Earthquake Rate Models for Evolving Induced Seismicity Hazard in the Central and Eastern US

    Science.gov (United States)

    Llenos, A. L.; Ellsworth, W. L.; Michael, A. J.

    2015-12-01

    Injection-induced earthquake rates can vary rapidly in space and time, which presents significant challenges to traditional probabilistic seismic hazard assessment methodologies that are based on a time-independent model of mainshock occurrence. To help society cope with rapidly evolving seismicity, the USGS is developing one-year hazard models for areas of induced seismicity in the central and eastern US to forecast the shaking due to all earthquakes, including aftershocks which are generally omitted from hazards assessments (Petersen et al., 2015). However, the spatial and temporal variability of the earthquake rates make them difficult to forecast even on time-scales as short as one year. An initial approach is to use the previous year's seismicity rate to forecast the next year's seismicity rate. However, in places such as northern Oklahoma the rates vary so rapidly over time that a simple linear extrapolation does not accurately forecast the future, even when the variability in the rates is modeled with simulations based on an Epidemic-Type Aftershock Sequence (ETAS) model (Ogata, JASA, 1988) to account for earthquake clustering. Instead of relying on a fixed time period for rate estimation, we explore another way to determine when the earthquake rate should be updated. This approach could also objectively identify new areas where the induced seismicity hazard model should be applied. We will estimate the background seismicity rate by optimizing a single set of ETAS aftershock triggering parameters across the most active induced seismicity zones -- Oklahoma, Guy-Greenbrier, the Raton Basin, and the Azle-Dallas-Fort Worth area -- with individual background rate parameters in each zone. The full seismicity rate, with uncertainties, can then be estimated using ETAS simulations and changes in rate can be detected by applying change point analysis in ETAS transformed time with methods already developed for Poisson processes.

  13. Communicating Earthquake Preparedness: The Influence of Induced Mood, Perceived Risk, and Gain or Loss Frames on Homeowners' Attitudes Toward General Precautionary Measures for Earthquakes.

    Science.gov (United States)

    Marti, Michèle; Stauffacher, Michael; Matthes, Jörg; Wiemer, Stefan

    2017-08-11

    Despite global efforts to reduce seismic risk, actual preparedness levels remain universally low. Although earthquake-resistant building design is the most efficient way to decrease potential losses, its application is not a legal requirement across all earthquake-prone countries and even if, often not strictly enforced. Risk communication encouraging homeowners to take precautionary measures is therefore an important means to enhance a country's earthquake resilience. Our study illustrates that specific interactions of mood, perceived risk, and frame type significantly affect homeowners' attitudes toward general precautionary measures for earthquakes. The interdependencies of the variables mood, risk information, and frame type were tested in an experimental 2 × 2 × 2 design (N = 156). Only in combination and not on their own, these variables effectively influence attitudes toward general precautionary measures for earthquakes. The control variables gender, "trait anxiety" index, and alteration of perceived risk adjust the effect. Overall, the group with the strongest attitudes toward general precautionary actions for earthquakes are homeowners with induced negative mood who process high-risk information and gain-framed messages. However, the conditions comprising induced negative mood, low-risk information and loss-frame and induced positive mood, low-risk information and gain-framed messages both also significantly influence homeowners' attitudes toward general precautionary measures for earthquakes. These results mostly confirm previous findings in the field of health communication. For practitioners, our study emphasizes that carefully compiled communication measures are a powerful means to encourage precautionary attitudes among homeowners, especially for those with an elevated perceived risk. © 2017 Society for Risk Analysis.

  14. Understanding the signature of rock coatings in laser-induced breakdown spectroscopy data

    Science.gov (United States)

    Lanza, Nina L.; Ollila, Ann M.; Cousin, Agnes; Wiens, Roger C.; Clegg, Samuel M.; Mangold, Nicolas; Bridges, Nathan; Cooper, Daniel; Schmidt, Mariek E.; Berger, Jeffrey; Arvidson, Raymond E.; Melikechi, Noureddine; Newsom, Horton E.; Tokar, Robert; Hardgrove, Craig; Mezzacappa, Alissa; Jackson, Ryan S.; Clark, Benton C.; Forni, Olivier; Maurice, Sylvestre; Nachon, Marion; Anderson, Ryan B.; Blank, Jennifer; Deans, Matthew; Delapp, Dorothea; Léveillé, Richard; McInroy, Rhonda; Martinez, Ronald; Meslin, Pierre-Yves; Pinet, Patrick

    2015-01-01

    Surface compositional features on rocks such as coatings and weathering rinds provide important information about past aqueous environments and water–rock interactions. The search for these features represents an important aspect of the Curiosity rover mission. With its unique ability to do fine-scale chemical depth profiling, the ChemCam laser-induced breakdown spectroscopy instrument (LIBS) onboard Curiosity can be used to both identify and analyze rock surface alteration features. In this study we analyze a terrestrial manganese-rich rock varnish coating on a basalt rock in the laboratory with the ChemCam engineering model to determine the LIBS signature of a natural rock coating. Results show that there is a systematic decrease in peak heights for elements such as Mn that are abundant in the coating but not the rock. There is significant spatial variation in the relative abundance of coating elements detected by LIBS depending on where on the rock surface sampled; this is due to the variability in thickness and spatial discontinuities in the coating. Similar trends have been identified in some martian rock targets in ChemCam data, suggesting that these rocks may have coatings or weathering rinds on their surfaces.

  15. Evaluation of earthquake-induced structural damages by wavelet transform

    Institute of Scientific and Technical Information of China (English)

    Hongnan Li; Tinghua Yi; Ming Gu; Linsheng Huo

    2009-01-01

    The dynamic behavior of inelastic structures during an earthquake is a complicated non-stationary process that is affected by the random characteristics of seismic ground motions.The conventional Fourier analysis describes the feature of a dynamic process by decomposing the signal into infinitely long sine and cosine series,which loses all time-located information.However,both time and frequency localizations are necessary for the analysis of an evolutionary spectrum of non-stationary processes.In this paper,an analytical approach for seismic ground motions is developed by applying the wavelet transform,which focuses on the energy input to the structure.The procedure of identification of the instantaneous modal parameters based on the continuous wavelet transform (CWT) is given in detail.And then,a novel method using the auto-regressive moving average (ARMA),called "prediction extension",is presented to remedy the edge effect during the numerical computation of the CWT.The effectiveness of the method is verified by the use of the benchmark model developed by the American Society of Civil Engineers (ASCE).Finally,a scale modal with three-storey reinforced concrete frame-share wall structure is made and tested on a shaking table to investigate the relation between the dynamic properties of structures and energy accumulation and its change rates during the earthquake.The results have shown that the wavelet transform is able to provide a deep insight into the identity of transient signals through time-frequency maps of the time variant spectral decomposition.

  16. Forecasting earthquake-induced landslides at the territorial scale by means of PBEE approaches

    Science.gov (United States)

    Berni, N.; Fanelli, G.; Ponziani, F.; Salciarini, D.; Stelluti, M.; Tamagnini, C.

    2012-04-01

    Models for predicting earthquake-induced landslide susceptibility on a regional scale are the main tools used by the Civil Protection Agencies to issue warning alarms after seismic events and to evaluate possible seismic hazard conditions for different earthquake scenarios. We present a model for susceptibility analysis based on a deterministic approach that subdivides the study area in a finite number of cells, assumes for each cell a simplified infinite slope model and considers the earthquake shaking as the landslide triggering factor. In this case, the stability conditions of the slopes are related both to the slope features (in terms of mechanical properties, geometrical and topographical settings and pore pressure regime) and to the earthquake characteristics (in terms of intensity, duration and frequency). Therefore, for a territorial analysis, the proposed method determines the limit conditions of the slope, given the seismic input, soil strength parameters, slope and depth of slip surface, and groundwater conditions for every cell in the study area. The procedure is ideally suited for the implementation on a GIS platform, in which the relevant information are stored for each cell. The seismic response of the slopes is analyzed by means of the Newmark's permanent displacement method. In Newmark's approach, seismic slope stability is measured in terms of the ratio of accumulated permanent displacement during the earthquake and the maximum allowable one, depending - in principle - on the definition of tolerable damage level. The computed permanent displacement depends critically on the actual slope stability conditions, quantified by the critical acceleration, i.e., the seismic acceleration bringing the slope to a state of (instantaneous) limit equilibrium. This methodology is applied in a study of shallow earthquake-induced landslides in central Italy. The triggering seismic input is defined in terms of synthetic accelerograms, constructed from the response

  17. Numerical Simulation of Changes in Groundwater-Level Induced by Earthquakes

    Science.gov (United States)

    Liu, Ching-Yi; Chia, Yeeping; Zheng, Ding-Qian

    2016-04-01

    Changes in groundwater level induced by earthquakes have been recorded worldwide. Sustained groundwater-level changes during earthquakes, primarily induced by the co-seismic strain due to fault displacement, are often observed in the confined aquifer. In the unconfined aquifer, sustained co-seismic changes can hardly be observed due to the rapid recovery of pore pressure change. In this study, field observation of co-seismic groundwater-level changes are showed. Also, the finite element software ABAQUS is used to simulate two-dimensional time-dependent pore pressure change in the aquifer due to fault displacement during earthquakes. Different physical properties are used to represent different types of aquifer. We adopted the 3-step method to simulate how earthquakes affect pore pressure in the 3 models, unconfined aquifer, confined aquifer and over-pressured confined layers. Results from the simulation gives us more details of how co-seismic and post-seismic pore pressure temporal changes are processed in different aquifers.

  18. Calculation of displacements on fractures intersecting canisters induced by earthquakes: Aberg, Beberg and Ceberg examples

    Energy Technology Data Exchange (ETDEWEB)

    LaPointe, P.R.; Cladouhos, T. [Golder Associates Inc. (Sweden); Follin, S. [Golder Grundteknik KB (Sweden)

    1999-01-01

    -wide earthquake source parameter database upon which the relations between surface rupture length, subsurface fault displacement and fault width (depth for vertical faults) is representative of Swedish earthquakes. Results of the calculations are presented in several ways. A canister is considered to be damaged or to have failed if a fracture intersecting the canister has an instantaneous or cumulative slip greater than 0.1m. Canisters may fail during a single earthquake, or due to the cumulative effects of multiple smaller earthquakes. Failure percentages for single earthquakes for a 100,000-year period range from a high of 0.59% for Aberg to a low of 0.03% for Ceberg. Failure for cumulative effects only vary from 0.056% for Aberg to 0.004% for Ceberg. Additional investigation of the single earthquakes that cause unacceptable slippage suggests that their probability of occurrence over a 100,000 year time period is very low, but that their consequences are more severe in that they tend to damage multiple canisters. When a damaging earthquake occurs, an average of from 0.4% to 1.8% of the canisters experience induced slips greater than 0.1m, the higher number representative of Aberg, and the lower value representative of Ceberg. Although earthquakes were simulated at distances over 100 km from the canister positions, single earthquakes that produced displacements greater than 0.1 m were confined to the immediate vicinity of the repository. A plot for the Ceberg simulations shows that over 95% of the single, damaging earthquakes are within I km of the canister that they damage, and 99% are within 2.5 km. The maximum distance for the simulations was approximately 31 km. This suggests that the vast majority of faults that might potentially produce damaging earthquakes lie with a few kilometers of the repository. The simulations suggest that faults tens or hundreds of kilometers distant from the canisters are very unlikely to produce damage due to single earthquake events 39 refs, 36

  19. The 2001-present induced earthquake sequence in the Raton Basin of northern New Mexico and southern Colorado

    Science.gov (United States)

    Rubinstein, Justin L.; Ellsworth, William L.; McGarr, Arthur F.; Benz, Harley M.

    2014-01-01

    We investigate the ongoing seismicity in the Raton Basin and find that the deep injection of wastewater from the coal‐bed methane field is responsible for inducing the majority of the seismicity since 2001. Many lines of evidence indicate that this earthquake sequence was induced by wastewater injection. First, there was a marked increase in seismicity shortly after major fluid injection began in the Raton Basin in 1999. From 1972 through July 2001, there was one M≥4 earthquake in the Raton Basin, whereas 12 occurred between August 2001 and 2013. The statistical likelihood that such a rate change would occur if earthquakes behaved randomly in time is 3.0%. Moreover, this rate change is limited to the area of industrial activity. Earthquake rates remain low in the surrounding area. Second, the vast majority of the seismicity is within 5 km of active disposal wells and is shallow, ranging between 2 and 8 km depth. The two most carefully studied earthquake sequences in 2001 and 2011 have earthquakes within 2 km of high‐volume, high‐injection‐rate wells. Third, injection wells in the area are commonly very high volume and high rate. Two wells adjacent to the August 2011 M 5.3 earthquake injected about 4.9 million cubic meters of wastewater before the earthquake, more than seven times the amount injected at the Rocky Mountain Arsenal well that caused damaging earthquakes near Denver, Colorado, in the 1960s. The August 2011 M 5.3 event is the second‐largest earthquake to date for which there is clear evidence that the earthquake sequence was induced by fluid injection.

  20. Research of the Activity of Earthquakes Induced by Water Injection of Salt Mining in Changning County, Sichuan Province

    Institute of Scientific and Technical Information of China (English)

    Ruan Xiang; Cheng Wanzheng; Zhang Yongjiu; Li Jun; Chen Yin

    2009-01-01

    According to information from on-the-spot investigations, the tectonics of salt mining areas and digital seismic records, we studied the activity of earthquakes induced by water pumping in and out of the salt mines in Shuanghe town, Changning county, Sichuan Province. The study found that the rates of water injection and extraction in the Shuanghe salt mining region were evenly matched before April 2006 and earthquake activity was stable. On the other hand, shallow small and moderate earthquake numbers increased sharply after the water injection rate became much larger than the water extraction rate. Large injection over a long time may causes the permeation of water through pre-existing small fractures and micro-cracks in the Changning anticlinal and accelerate the rupture of micro tectonic formations in nearby regions, inducing small earthquake swarm activity. The Q value calculated by using digital earthquake records indicates a relatively inhomogeneous medium in this area. The results of the accurate location of small earthquakes show that sources are relatively shallow and are concentrated at a depth of 2km to 3km. Focal mechanism solutions reveal a normal dip-slip character of shallow earthquakes. All of these show certain characteristics of earthquake activity induced by water injection.

  1. Rotation of vertically oriented objects during earthquakes

    Science.gov (United States)

    Hinzen, Klaus-G.

    2012-10-01

    Vertically oriented objects, such as tombstones, monuments, columns, and stone lanterns, are often observed to shift and rotate during earthquake ground motion. Such observations are usually limited to the mesoseismal zone. Whether near-field rotational ground motion components are necessary in addition to pure translational movements to explain the observed rotations is an open question. We summarize rotation data from seven earthquakes between 1925 and 2009 and perform analog and numeric rotation testing with vertically oriented objects. The free-rocking motion of a marble block on a sliding table is disturbed by a pulse in the direction orthogonal to the rocking motion. When the impulse is sufficiently strong and occurs at the `right' moment, it induces significant rotation of the block. Numeric experiments of a free-rocking block show that the initiation of vertical block rotation by a cycloidal acceleration pulse applied orthogonal to the rocking axis depends on the amplitude of the pulse and its phase relation to the rocking cycle. Rotation occurs when the pulse acceleration exceeds the threshold necessary to provoke rocking of a resting block, and the rocking block approaches its equilibrium position. Experiments with blocks subjected to full 3D strong motion signals measured during the 2009 L'Aquila earthquake confirm the observations from the tests with analytic ground motions. Significant differences in the rotational behavior of a monolithic block and two stacked blocks exist.

  2. RhoA/ROCK signaling in chondrogenic differentiation of MSCs induced by TGF-β1

    Institute of Scientific and Technical Information of China (English)

    Liang Xu; Shuhua Yang; Hongtao Tian

    2006-01-01

    Objective: To investigate the role of RhoA/ROCK in the process of chondrogenic differentiation of MSCs in vitro induced by TGF-β1. Methods: MSCs were isolated from rat bone marrow, cultured and passaged. The cultured MSCs at the 3rd passage were induced to differentiate into chondrocytes in induction medium containing TGF-β1, the expressions of RhoA and ROCK1/2 in the induced MSCs cells were detected by Western-blot and RT-PCR. Results: In parallel to chondrogenic marker gene expressions of collagen Ⅱ and aggrecan, ROCK inhibition by Y27632 in these cells caused a significant decrease in mRNA level of collagen Ⅱ. Conclusion: The results suggest that RhoA/ROCK pathway may play an important and complex role in regulation of chondrogenic differentiation and gene expression.

  3. ROCK signalling induced gene expression changes in mouse pancreatic ductal adenocarcinoma cells

    Science.gov (United States)

    Rath, Nicola; Kalna, Gabriela; Clark, William; Olson, Michael F.

    2016-01-01

    The RhoA and RhoC GTPases act via the ROCK1 and ROCK2 kinases to promote actomyosin contraction, resulting in directly induced changes in cytoskeleton structures and altered gene transcription via several possible indirect routes. Elevated activation of the Rho/ROCK pathway has been reported in several diseases and pathological conditions, including disorders of the central nervous system, cardiovascular dysfunctions and cancer. To determine how increased ROCK signalling affected gene expression in pancreatic ductal adenocarcinoma (PDAC) cells, we transduced mouse PDAC cell lines with retroviral constructs encoding fusion proteins that enable conditional activation of ROCK1 or ROCK2, and subsequently performed RNA sequencing (RNA-Seq) using the Illumina NextSeq 500 platform. We describe how gene expression datasets were generated and validated by comparing data obtained by RNA-Seq with RT-qPCR results. Activation of ROCK1 or ROCK2 signalling induced significant changes in gene expression that could be used to determine how actomyosin contractility influences gene transcription in pancreatic cancer. PMID:27824338

  4. Role of ROCK Isoforms in Regulation of Stiffness Induced Myofibroblast Differentiation in Lung Fibrosis.

    Science.gov (United States)

    Htwe, Su S; Cha, Byung H; Yue, Kan; Khademhosseini, Ali; Knox, Alan J; Ghaemmaghami, Amir M

    2017-02-22

    Fibrosis is a major cause of progressive organ dysfunction in several chronic pulmonary diseases. Rho associated coiled-coil forming kinase (ROCK) has shown to be involved in myofibroblast differentiation driven by altered matrix stiffness in fibrotic state. There are two known ROCK isoforms in human, ROCK1 (ROKβ) and ROCK2 (ROKα), but specific role of each isoform in myofibroblast differentiation in lung fibrosis remains unknown. To study this, we developed a Gelatin methacryloyl (GelMA) hydrogel based culture system with different stiffness levels relevant to healthy and fibrotic lungs. We have shown that stiff matrix and not soft matrix, can induce myofibroblast differentiation with high αSMA expression. Furthermore, our data confirm that the inhibition of ROCK signalling by a pharmacological inhibitor (i.e. Y27632) attenuates stiffness induced αSMA expression and fibre assembly in myofibroblasts. To assess the role of ROCK isoforms in this process we used siRNA to knock down the expression of each isoform. Our data showed that knocking down either ROCK1 or ROCK2 did not result in a reduction in αSMA expression in myofibroblasts on stiff matrix as opposed to soft matrix where αSMA expression was reduced significantly. Paradoxically, on stiff matrix, the absence of one isoform (particularly ROCK2) exaggerated αSMA expression and led to thick fibre assembly. Moreover complete loss of αSMA fibre assembly was seen only in the absence of both ROCK isoforms suggesting that both isoforms are implicated in this process. Overall our results indicate the differential role of ROCK isoforms in myofibroblast differentiation on soft and stiff matrices.

  5. Decadal Erosion Rates Derived From An Earthquake-Induced Landslide Region, Central Taiwan

    Science.gov (United States)

    Chan, Y.; Lu, C.; Chang, K.; Chen, R.

    2010-12-01

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

  6. Investigation of ULF magnetic pulsations, air conductivity changes, and infra red signatures associated with the 30 October Alum Rock M5.4 earthquake

    Directory of Open Access Journals (Sweden)

    T. Bleier

    2009-04-01

    Full Text Available Several electromagnetic signal types were observed prior to and immediately after 30 October 2007 (Local Time M5.4 earthquake at Alum Rock, Ca with an epicenter ~15 km NE of San Jose Ca. The area where this event occurred had been monitored since November 2005 by a QuakeFinder magnetometer site, unit 609, 2 km from the epicenter. This instrument is one of 53 stations of the QuakeFinder (QF California Magnetometer Network-CalMagNet. This station included an ultra low frequency (ULF 3-axis induction magnetometer, a simple air conductivity sensor to measure relative airborne ion concentrations, and a geophone to identify the arrival of the P-wave from an earthquake. Similar in frequency content to the increased ULF activity reported two weeks prior to the Loma Prieta M7.0 quake in 1989 (Fraser-Smith, 1990, 1991, the QF station detected activity in the 0.01–12 Hz bands, but it consisted of an increasing number of short duration (1 to 30 s duration pulsations. The pulsations peaked around 13 days prior to the event. The amplitudes of the pulses were strong, (3–20 nT, compared to the average ambient noise at the site, (10–250 pT, which included a component arising from the Bay Area Rapid Transit (BART operations. The QF station also detected different pulse shapes, e.g. negative or positive only polarity, with some pulses including a combination of positive and negative. Typical pulse counts over the previous year ranged from 0–15 per day, while the count rose to 176 (east-west channel on 17 October, 13 days prior to the quake. The air conductivity sensor saturated for over 14 h during the night and morning prior to the quake, which occurred at 20:29 LT. Anomalous IR signatures were also observed in the general area, within 50 km of the epicenter, during the 2 weeks prior to the quake. These three simultaneous EM phenomena were compared with data collected over a 1–2-year period at the site. The data was also compared against accounts of air

  7. Seismically induced environmental effects in costal areas : the 1783, 1905 and 1908 earthquakes in Calabria and Sicily, (Southern Italy).

    Science.gov (United States)

    Porfido, S.; Esposito, E.; Violante, C.; Sacchi, M.; Guerrieri, L.; Serva, L.; Sciarrotta, S.

    2009-04-01

    Calabria and Sicily's Coast, particularly in the Messina Strait, is one of the most seismically active areas of the Southern Italy. Since 1783, there have been seven earthquakes with magnitude ranging between 6.0 and 7.2 These earthquakes have produced wide damages on the MCS Intensities scale of X or greater. The high rate of seismic activity in the region is related to the complex geologic setting resulting in a number of different sources of potentially damaging earthquakes. All these earthquake induced numerous and spectacular coseismic environmental effects overall along the coast where the impact was particularly catastrophic. These earthquakes caused several changes in elevation, due to tectonic deformations, landslides and settlements (i.e along both sides of the Messina Straits, 1908 event), relevant landslides (the February6, 1783 event triggered in Scilla, along the cliff of the M. Pacì a huge rock avalanche estimate of 5 Mm3 in the areal zone and 3 Mm3 in the submarine zone (Bozzano et al 2006), that fell into the sea generating a disastrous tsunamis), ground fractures (in the Capo Vaticano promontory area, 1905 event; in Messina Reggio C., Villa S. Giovanni, 1908 event); liquefaction phenomena (in the area of Messina, Ganzirri and Reggio Calabria, 1908 event), and catastrophic tsunamis (five induced by the 1783 Calabrian seismic sequence, other two by 1905 and 1908 events, Graziani et al 2006). The run-up observed ranging from few cm to tens of m: the highest tsunami wave was about 16 m in Scilla (Feb. 6, 1783 tsunami), 13 m in Pellaro (1908 event) and 1,30 m along the Calabrian coast (1905 tsunami) . Portion of the coast were lost, most of them eroded by the tsunamis with a coastline retreat and flooded the shore for several hundred meters inland depositing a large amount of silt and fish, and in some case killing people (i.e 1500 in Scilla and 28 in Messina during the February 6, 1783 tsunami, Barbano 2008; Porfido et al.,2008). Finally, it is

  8. Hydrological changes due to the M7.0 earthquake at Iwaki, Fukushima induced by the 2011 Tohoku-oki earthquake, Japan

    Science.gov (United States)

    Sato, T.; Kazahaya, K.; Yasuhara, M.; Itoh, J.; Takahashi, H. A.; Morikawa, N.; Takahashi, M.; Inamura, A.; Handa, H.; Matsumoto, N.

    2011-12-01

    After a month of the 2011 Tohoku-oki earthquake (Mw9.0) in Japan, two normal faults located 300 km southwest of the epicenter moved with several earthquakes (Max Mw7.0, 11 April 2011). Significant hydrological anomalies occurred around the faults after the movements. We have surveyed spatial distribution of the hydrological anomalies within 10 km of the faults, and analyzed chemical composition of some hot spring waters including the spouting waters which began to discharge just after the M7.0 earthquake. Increases of groundwater level were observed on the lower block of the normal faults. Especially water level of a hot spring well increased about 10 m in the Iwaki Yumoto area, located 3 km away from the faults. The GPS observation by the Geospatial Information Authority of Japan (GSI) showed that contraction of 16 cm between the two GPS stations 9.6 km away and uplift of 6 cm occurred simultaneously in the Iwaki Yumoto area. The observation results for the crustal deformation indicated that the increases of groundwater level were caused by contraction strain change due to the fault movement. On the other hand, decreases of groundwater level were observed on the upper block of the faults, which was thought to be caused by dilatation strain change due to the fault movement. In the Iwaki Yumoto area, a large amount of hot water with higher temperature (58 degree-C) has flowed out from the old coal mine after the M7.0 earthquake. The flow rate was up to about 10,000 m3/day on May, 2011. The chemical composition of this hot water has gradually changed to that of 1000m-deep-groundwater from boreholes drilled to basement rocks in this area. The analytical result indicates that the outflow occurred by discharging of the hot groundwater stored in the fractures of the basement rocks to the roadway of the old coal mine by contraction strain changes of the basement rocks due to the M7.0 earthquake.

  9. Inhibition of ROCK2 expression protects against methamphetamine-induced neurotoxicity in PC12 cells.

    Science.gov (United States)

    Yang, Xingyi; Liu, Yunyun; Liu, Chao; Xie, Weibing; Huang, Enping; Huang, Weiye; Wang, Jiawen; Chen, Ling; Wang, Huipin; Qiu, Pingming; Xu, Jingtao; Zhang, Fu; Wang, Huijun

    2013-10-02

    Methamphetamine is a type of psychoactive drug. It is well known that neurotoxicity caused by Methamphetamine(METH) can damage the nervous system and lead to apoptosis and cell loss of dopaminergic neurons. ROCK2 is a prominent target for gene therapy because its inhibition has proved to have a protective effect in various cell lines and pathophysiological conditions. Although several of the negative effects of METH on the dopaminergic system have been studied, the protective molecular mechanisms and the effective treatment of METH-induced apoptosis remain to be clarified. We hypothesized that ROCK2 is involved in METH-induced apoptosis. We tested our hypothesis using RT-PCR and western blotting to analyze whether silencing of ROCK2 with small interfering RNA (siROCK2) could reduce damage and apoptosis in PC12 cells after METH exposure. Increases in viability and cytomorphological changes were detected by MTT assay and bright field microscopy after pretreatment of METH-treated PC12 cells with 100 nM siROCK2. Apoptosis decreased significantly after ROCK2 silencing, as shown by Annexin V and TUNEL staining. The results show that ROCK2 is a possible gene target for therapeutics in METH-induced neurotoxicity in vitro, providing a foundation for future in vivo research.

  10. Seismic evidence for rock damage and healing on the San Andreas fault associated with the 2004 M 6.0 Parkfield earthquake

    Science.gov (United States)

    Li, Y.-G.; Chen, P.; Cochran, E.S.; Vidale, J.E.; Burdette, T.

    2006-01-01

    We deployed a dense linear array of 45 seismometers across and along the San Andreas fault near Parkfield a week after the M 6.0 Parkfield earthquake on 28 September 2004 to record fault-zone seismic waves generated by aftershocks and explosions. Seismic stations and explosions were co-sited with our previous experiment conducted in 2002. The data from repeated shots detonated in the fall of 2002 and 3 months after the 2004 M 6.0 mainshock show ???1.0%-1.5% decreases in seismic-wave velocity within an ???200-m-wide zone along the fault strike and smaller changes (0.2%-0.5%) beyond this zone, most likely due to the coseismic damage of rocks during dynamic rupture in the 2004 M 6.0 earthquake. The width of the damage zone characterized by larger velocity changes is consistent with the low-velocity waveguide model on the San Andreas fault, near Parkfield, that we derived from fault-zone trapped waves (Li et al., 2004). The damage zone is not symmetric but extends farther on the southwest side of the main fault trace. Waveform cross-correlations for repeated aftershocks in 21 clusters, with a total of ???130 events, located at different depths and distances from the array site show ???0.7%-1.1% increases in S-wave velocity within the fault zone in 3 months starting a week after the earthquake. The velocity recovery indicates that the damaged rock has been healing and regaining the strength through rigidity recovery with time, most likely . due to the closure of cracks opened during the mainshock. We estimate that the net decrease in seismic velocities within the fault zone was at least ???2.5%, caused by the 2004 M 6.0 Parkfield earthquake. The healing rate was largest in the earlier stage of the postmainshock healing process. The magnitude of fault healing varies along the rupture zone, being slightly larger for the healing beneath Middle Mountain, correlating well with an area of large mapped slip. The fault healing is most prominent at depths above ???7 km.

  11. Were the May 2012 Emilia-Romagna earthquakes induced? A coupled flow-geomechanics modeling assessment

    Science.gov (United States)

    Juanes, R.; Jha, B.; Hager, B. H.; Shaw, J. H.; Plesch, A.; Astiz, L.; Dieterich, J. H.; Frohlich, C.

    2016-07-01

    Seismicity induced by fluid injection and withdrawal has emerged as a central element of the scientific discussion around subsurface technologies that tap into water and energy resources. Here we present the application of coupled flow-geomechanics simulation technology to the post mortem analysis of a sequence of damaging earthquakes (Mw = 6.0 and 5.8) in May 2012 near the Cavone oil field, in northern Italy. This sequence raised the question of whether these earthquakes might have been triggered by activities due to oil and gas production. Our analysis strongly suggests that the combined effects of fluid production and injection from the Cavone field were not a driver for the observed seismicity. More generally, our study illustrates that computational modeling of coupled flow and geomechanics permits the integration of geologic, seismotectonic, well log, fluid pressure and flow rate, and geodetic data and provides a promising approach for assessing and managing hazards associated with induced seismicity.

  12. Centrifuge model test on earthquake-induced differential settlement of foundation on cohesive ground

    Institute of Scientific and Technical Information of China (English)

    SHAMOTO; Yasuhiro; HOTTA; Hiroyuki

    2009-01-01

    Dynamic centrifuge model test was conducted to study the earthquake-induced differential settlement of foundation on cohesive ground, and the influence of asymmetry of building was investigated. During the experiment, the overconsolidated kaolin clay ground with a three-dimensional asymmetrical structure model was shaken by a basically balanced input motion, and bender elements were used to measure shear wave velocities of model ground to reveal the soil fabric evolution during and after shaking. The test results show that, the total seismic settlement of foundation is composed of instantaneous and long-term post-earthquake settlements, and most of the differential settlement occurs immediately after the earthquake while the post-earthquake settlement is relatively uniform despite its large amplitude. The asymmetry of building affects the settlement behavior considerably. Compared with 1-or 2-dimensional structures, more evident differential settlement occurs under threedimensional asymmetrical building during shaking, which accounts for one-half of the total seismic settlements and results in complex spatial tilting effects of foundation.

  13. Centrifuge model test on earthquake-induced differential settlement of foundation on cohesive ground

    Institute of Scientific and Technical Information of China (English)

    ZHOU YanGuo; CHEN YunMin; SHAMOTO Yasuhiro; HOTTA Hiroyuki

    2009-01-01

    Dynamic centrifuge model test was conducted to study the earthquake-induced differential settlement of foundation on cohesive ground, and the influence of asymmetry of building was investigated. During the experiment, the overconsolidated kaolin clay ground with a three-dimensional asymmetrical structure model was shaken by a basically balanced input motion, and bender elements were used to measure shear wave velocities of model ground to reveal the soil fabric evolution during and after shaking. The test results show that, the total seismic settlement of foundation is composed of instantaneous and long-term post-earthquake settlements, and most of the differential settlement occurs immediately after the earthquake while the post-earthquake settlement is relatively uniform despite its large amplitude. The asymmetry of building affects the settlement behavior considerably. Compared with 1- or 2-dimensional structures, more evident differential settlement occurs under three-dimensional asymmetrical building during shaking, which accounts for one-half of the total seismic settlements and results in complex spatial tilting effects of foundation.

  14. Acoustically induced slip in sheared granular layers: Application to dynamic earthquake triggering

    Science.gov (United States)

    Ferdowsi, Behrooz; Griffa, Michele; Guyer, Robert A.; Johnson, Paul A.; Marone, Chris; Carmeliet, Jan

    2015-11-01

    A fundamental mystery in earthquake physics is "how can an earthquake be triggered by distant seismic sources?" Here we use discrete element method simulations of a granular layer, during stick slip, that is subject to transient vibrational excitation to gain further insight into the physics of dynamic earthquake triggering. Using Coulomb friction law for grains interaction, we observe delayed triggering of slip in the granular gouge. We find that at a critical vibrational amplitude (strain) there is an abrupt transition from negligible time-advanced slip (clock advance) to full clock advance; i.e., transient vibration and triggered slip are simultaneous. The critical strain is of order 10-6, similar to observations in the laboratory and in Earth. The transition is related to frictional weakening of the granular layer due to a dramatic decrease in coordination number and the weakening of the contact force network. Associated with this frictional weakening is a pronounced decrease in the elastic modulus of the layer. The study has important implications for mechanisms of triggered earthquakes and induced seismic events and points out the underlying processes in response of the fault gouge to dynamic transient stresses.

  15. ROCK2 is involved in accelerated fetal lung development induced by in vivo lung distension.

    Science.gov (United States)

    Cloutier, Marc; Tremblay, Monique; Piedboeuf, Bruno

    2010-10-01

    Lung development is strongly influenced by its state of distension. For instance, increasing distension induced by fetal tracheal occlusion (TO) stimulates lung development. In contrast, oligohydramnios (OH) reduces lung distending forces and results in lung hypoplasia. We hypothesize that Rho/Rho-associated kinase (ROCK) pathway plays an important role as mechanosensor in vivo acting either directly or indirectly in the translation of increased distension into acceleration of lung growth. TO was done in fetal mice sacrificed either 3 or 24 hr later; in a subset of dam, fasudil, a specific ROCK inhibitor, or vehicle was injected intra-peritoneally. OH was done by puncture of the amniotic sac. ROCK2 protein levels were assessed by Western blot and immunohistochemistry (IHC); lung development was assessed by measuring the generation of distal respiratory airway. Significant differences were found in ROCK2 protein levels between TO and Sham-TO at 3 and 24 hr, but not for ROCK1. Indeed, IHC revealed that ROCK2 staining was sparse and restricted to a few mesenchymal cells in Sham-TO, whereas it was strong in acini of TO lungs. OH lungs expressed lower levels of ROCK2 in the acini when compared to untouched controls. In fasudil-treated animals, the degree of lung development following TO was significantly lower than in the group injected with vehicle. At the dose regimen used, fasudil did not affect normal lung development, as observed in the untouched animals. In summary, ROCK2 protein levels was affected by the degree of lung expansion and blunting ROCK activity abolished the response to increased lung distension, suggesting that ROCK is a key regulator in TO-induced accelerated lung development.

  16. Reservoir-induced Earthquakes for the Sanjiangkou Reservoir in Chongqing%重庆三江口水库诱发地震分析研究

    Institute of Scientific and Technical Information of China (English)

    吴建超; 张丽芬; 汪旭涛; 蔡永建

    2015-01-01

    Based on field investigations and previous research results,this study analyzes the tec-tonic background,seismic activity,and hydrogeology condition of the Sanjiangkou reservoir area. The Yushan fault is the main fault located in the southeast margin of the Sanjiangkou reservoir area.The other major fault is termed the Mawu fault,which is exposed in the west margin of the Sanjiangkou reservoir area.The active age of the Yushan fault is mid-Pleistocene and the Mawu fault is pre-Quaternary.The level of historic and current seismicity is low in the reservoir area. Employing structural analogy and probabilistic statistic methods,the probability of the induced earthquake in the Sanjiangkou reservoir area is discussed.These results are used to compare the Sanjiangkou reservoir with other reservoirs that have experienced earthquakes.The structural analogy method analysis showed that the possibility of tectonic-type reservoir-induced earth-quakes is small following impoundment.However,there is the possibility of a karst subsidence-type reservoir-induced earthquake.This event could occur because of the existence of a large amount of thick layers of limestone in the reservoir area that could foster karst development.The loading and infiltration effects of water may easily cause rock collapse and crack propagation in the karst cave.This would induce a karst subsidence-type reservoir-induced earthquake.Consider-ing the conditions of the Sanjiangkou reservoir area eight induced earthquake factors were selected to conduct the probabilistic prediction of the earthquake magnitude.These factors were reservoir water depth,lithology,regional state of stress,fault activity,degree of karst development,fault permeable depth,communication with the reservoir water,and seismic activity background.Based on the geological conditions and induced earthquake environment of the Sanjiangkou reservoir area,the reservoir area was divided into three segments:the head (Xintanzi

  17. Anisotropy of magnetic susceptibility of rocks induced by experimental deformation

    Directory of Open Access Journals (Sweden)

    J. Zhou

    1997-06-01

    Full Text Available In the present paper, the influence of the rheological process on the Anisotropy of Magnetic Susceptibility (AMS of rocks is studied experimentally. The cylindrical samples of quartz-magnetite rock undergo a process under the confining stress of 300 MPa, temperature of 500-800 °C and strain rate of 5 ´ 10-5 - 1 ´ 10-4/s. The residual deformation after the above process ranges 9-42%, depending on the experimental condition. It is found that the magnetic susceptibilities and the shapes of magnetic grains in these samples are almost isotropic before deformation. After being deformed, these samples show certain amounts of anisotropy of magnetic susceptibility and the axes of maximum principal susceptibilities deviate from the original ones more or less. Furthermore, the grains become oblate-ellipsoidal and a certain preferred orientation occurs. The grain shape anisotropy seems to be the main reason for AMS formation. It appears that there is a limitation of the piezomagnetic theory in explaining some tectonomagnetic phenomena. The results obtained in this study imply that ductile deformation at high temperature and pressure in depth during a long time-process may result in another kind of response in rock magnetism, which could be a new mechanism of tectonomagnetic variation.

  18. Thresholds for earthquake-induced hydrological changes in sedimentary aquifers: a record from 9 earthquakes and 107 boreholes in central New Zealand

    Science.gov (United States)

    Weaver, Konrad; Cox, Simon; Holden, Caroline; Townend, John

    2016-04-01

    A dense hydrogeological network in central New Zealand has recorded groundwater fluctuations from 12 years of seismic events. Hydrological data over the past 15 years were assessed in 107 boreholes at depths of 4 - 405 m. Nine seismic events (M≥5.9) occurred at near- to far-field distances of 10 - 913 km, shaking the sedimentary aquifers at a wide range of 10-4 to 103 J/m3 seismic energy densities. The earthquakes produced 258 detectable hydrological responses, exhibiting different polarities (rise or fall), amplitudes (2 to 820 mm, -859 to -2 mm) and timescales (15 min to day [s]). Shaking parameters were calculated from 28 proximal GeoNet broadband seismometers, providing local estimates of peak ground acceleration (PGA) and velocity (PGV), Arias intensity, and spectral amplitudes. ShakeMap model solutions, utilising ground motion prediction equations (GMPEs), were also acquired at borehole sites. Continuous oceanic tidal responses of 38 boreholes were derived using Baytap08, with temporal transmissivity and earthquake-induced changes estimated from tidal properties. The earthquake-induced changes to groundwater level and tidal response are used to infer those events which caused aquifer deformation and changes to the groundwater flow regime. A transient (15 min to 2 hr) / permanent (15 min to day [s]) deformation boundary is observed when shaking reaches ˜1 %g PGA. As well as defining thresholds at which hydrological changes occurred, the central New Zealand dataset provided an opportunity to examine aquifer ability in resistance to the effects induced by earthquakes. Where monitoring is dense and continuous, the absence of responses under certain levels of shaking is equally informative and helps delineate causative processes. On-going work utilises data mining to assess the contribution of seismic, hydrological, and geological parameters to earthquake-induced hydrological changes in sedimentary aquifer systems.

  19. Effects of active fault types on earthquake-induced deep-seated landslides: A study of historical cases in Japan

    Science.gov (United States)

    Chen, Chi-Wen; Iida, Tomoyuki; Yamada, Ryuji

    2017-10-01

    We investigated the relationship between the distribution of deep-seated landslides (DSLs; landslide volume > 105 m3) induced by inland earthquakes as well as the distribution of corresponding active faults by compiling preexisting documents on historical DSL occurrence records. The following points are found: (1) The DSLs induced by reverse fault earthquakes tend to occur equally within a wide range of about 20 km from the faults, whilst > 80% of DSLs induced by strike-slip fault earthquakes are concentrated within a small range of about 5 km from the faults. (2) Most of the DSLs are distributed on the hanging wall side of the active faults. (3) The distribution of some historical DSLs may reflect the directivity of the seismic waves of the historical earthquakes. The minimum peak ground velocity (PGV) and peak ground acceleration (PGA) during earthquakes that can induce DSLs are estimated to be 15-20 cm s- 1 and 300-400 cm s- 2, although most of the DSLs examined were induced by strike-slip fault earthquakes with PGV > 60 cm s- 1 and PGA > 900 cm s- 2. This discrepancy may be attributed to a possible limitation of the proposed equation, which was established mainly for cases of reverse fault earthquakes. It is implied that the type of fault, the side of the epicenter location (hanging wall/footwall side), and the directivity of seismic waves should be considered for assessing the distribution of ground motion in terms of DSL occurrence, and that these factors may reflect the level of risk for earthquake-induced landslides around active faults.

  20. Spectral-induced polarization characteristics of rocks from Shinyemi deposit in Northeastern South Korea

    Science.gov (United States)

    Park, Samgyu; Shin, Seung Wook; Son, Jeong-Sul; Kim, Changryol

    2016-04-01

    Contact metasomatism between carbonate and igneous rocks leads to the formation of skarn deposits, and ore minerals are abundant. Geophysical methods that visualize the distributions of physical properties have been utilized to determine lithological boundaries in ore deposits. In particular, spectral-induced polarization (SIP) is the most effective of those methods for mineral exploration because it can obtain not only the boundaries but also the abundance and grain size of ore minerals. It is crucial to characterize the SIP responses of in situ rocks for a more realistic interpretation. Thus, typical rocks composed of igneous rock, skarn rock, skarn ore, and carbonate rock were sampled from drilling cores in the Shinyemi deposit, which is one of the well-known skarn deposits in Northeastern South Korea. The purpose of this study was to characterize the SIP responses of rocks by laboratory measurements. The characterization was performed by evaluating spectra and IP parameters. The IP properties were acquired from equivalent circuit analysis using a circuit model based on the electrochemical theory, and the analysis results of this circuit model were relatively well fit compared with those of the traditional Dias and Cole-Cole models. The frequency responses below 100 Hz in the spectra and the chargeability values of the skarn rocks and ores containing magnetite were relatively strong and high, respectively, compared with those of non-mineralized igneous and carbonate rocks. Therefore, it is considered that these characteristics are dependent on the abundance of magnetite. In case of the skarn ores with high magnetite content, the resistivity values were significantly low and the relaxation time values were influenced by the grain size of magnetite. On the other hand, it is considered that the DC resistivity and the relaxation time values of the igneous and carbonate rocks are slightly related to the porosity and the grade of hydrothermal alteration, respectively.

  1. Study on loss estimation of earthquake induced fire%地震火灾损失评估研究

    Institute of Scientific and Technical Information of China (English)

    林均岐

    2000-01-01

    地震火灾是一种严重的地震次生灾害.历史地震资料表明,地震火灾造成的损失有时甚至超过地震的直接破坏所造成的损失.本文根据目前我国地震现场灾害损失的评估方法,结合我国地震结构损失评估的经验,建立了地震火灾损失的评估方法.%Earthquake fire is a serious secondary disaster duringa earthquake.Loss induced by earthquake fire may be much more than the loss induced directly by the damage of earthquake.Based on the estimation method of earthquake damage and the experience in structural damage during earthquakes in China,the method to estimate the loss of earthquake fire is given.

  2. Plant-induced weathering of a basaltic rock: experimental evidence

    Science.gov (United States)

    Hinsinger, Philippe; Fernandes Barros, Omar Neto; Benedetti, Marc F.; Noack, Yves; Callot, Gabriel

    2001-01-01

    The active role of higher plants in the weathering of silicate minerals and rocks is still a question for debate. The present work aimed at providing experimental evidence of the important role of a range of crop plants in such processes. In order to quantitatively assess the possible effect of these diverse plant species on the weathering of a basaltic rock, two laboratory experiments were carried out at room temperature. These compared the amounts of elements released from basalt when leached with a dilute salt solution in the presence or absence of crop plants grown for up to 36 days. For Si, Ca, Mg, and Na, plants resulted in an increase in the release rate by a factor ranging from 1 to 5 in most cases. Ca and Na seemed to be preferentially released relative to other elements, suggesting that plagioclase dissolved faster than the other constituents of the studied basalt. Negligible amounts of Fe were released in the absence of plants as a consequence of the neutral pH and atmospheric pO 2 that were maintained in the leaching solution. However, the amounts of Fe released from basalt in the presence of plants were up to 100- to 500-fold larger than in the absence of plants, for banana and maize. The kinetics of dissolution of basalt in the absence of plants showed a constantly decreasing release rate over the whole duration of the experiment (36 days). No steady state value was reached both in the absence and presence of banana plants. However, in the latter case, the rates remained at a high initial level over a longer period of time (up to 15 days) before starting to decrease. For Fe, the maximum rate of release was reached beyond 4 days and this rate remained high up to 22 days of growth of banana. The possible mechanisms responsible for this enhanced release of elements from basalt in the presence of plants are discussed. Although these mechanisms need to be elucidated, the present results clearly show that higher plants can considerably affect the kinetics

  3. Detection of earthquake induced radon precursors by Hilbert Huang Transform

    Science.gov (United States)

    Barman, Chiranjib; Ghose, Debasis; Sinha, Bikash; Deb, Argha

    2016-10-01

    Continuous measurement of radon-222 concentration in soil was carried out across duration of one year at a geologically faulted area having high regional heat flow to detect anomalies caused by seismic activities. The data reveals a range of periodicities present in the radon time series. To identify seismic induced radon changes we treat the time series data through various filtering methods to remove inherent periodicities. The Ensemble Empirical Mode Decomposition (EEMD) is deployed to decompose the signal into its characteristic modes. Hilbert Huang Transform (HHT) is applied for the first time on the physically significant modes obtained by EEMD to represent time-energy-frequency of the recorded soil radon time series. After removing the periodic and quasi-periodic constituents from the original time series, the simulated result shows a forceful correlation in recorded radon-222 anomalies with regional and local seismic events.

  4. Factors promoting injection-induced seismicity on basement faults: Insights from the 2012 Milan, Kansas Earthquake

    Science.gov (United States)

    Hearn, E. H.; Koltermann, C.

    2016-12-01

    The November 12, 2014 M 4.8 Milan Kansas earthquake occurred in a region where saltwater disposal had recently undergone a dramatic increase. Because this region is instrumented with seismic arrays, and data on hydrogeological properties and wastewater injection rates are available, it is an ideal target for modeling injection-induced seismicity. We have developed a suite of MODFLOW groundwater flow models to explore hydrogeological conditions consistent with triggering the Milan earthquake given injection schedules and rates at nearby wells, with the goal of assessing whether these models are consistent with new seismicity and injection rate data reflecting a state-mandated reduction in injection at some wells. Hydraulic properties of the lower, middle and upper Arbuckle Formation and the fault damage zone were systematically varied, as well as the depth to the hypocenter and geometry of the Milan earthquake fault. Fault damage zone hydraulic conductivity and storage coefficient were consistent with a range of of hydraulic diffusivities inferred from aftershock migration (Choy et al., 2016). A minimum Coulomb stress threshold of 0.01 MPa is exceeded by the time of the Milan earthquake for a range of reasonable hydraulic parameters, but an increase exceeding 0.1 MPa at the Milan hypocenter is not obtained for any models we tested. This suggests that the Milan fault patch was critically stressed prior to the earthquake, consistent with orientation of the fault in the local stress field (Schwab et al., 2015; Walsh, 2015) and the increased hydraulic conductivity of critically-stressed faults (Barton et al., 1995). Modeled pore pressures and Coulomb stress changes at the Milan earthquake hypocenter are most sensitive to fault damage zone hydraulic conductivity and assumed hypocenter depth (which controls where the fault zone intersects with the base of the Arbuckle Formation). Though seismic reflection profiles from the modeled region show faults cutting the Arbuckle

  5. Determination of blast-induced ground vibration equations for rocks using mechanical and geological properties

    Institute of Scientific and Technical Information of China (English)

    Ranjan Kumar; Deepankar Choudhury; Kapilesh Bhargava

    2016-01-01

    In the recent decades, effects of blast loads on natural and man-made structures have gained considerable attention due to increase in threat from various man-made activities. Site-specific empirical relationships for calculation of blast-induced vibration parameters like peak particle velocity (PPV) and peak particle displacement (PPD) are commonly used for estimation of blast loads in design. However, these relation-ships are not able to consider the variation in rock parameters and uncertainty of in situ conditions. In this paper, a total of 1089 published blast data of various researchers in different rock sites have been collected and used to propose generalized empirical model for PPV by considering the effects of rock parameters like unit weight, rock quality designation (RQD), geological strength index (GSI), and uniaxial compressive strength (UCS). The proposed PPV model has a good correlation coefficient and hence it can be directly used in prediction of blast-induced vibrations in rocks. Standard errors and coefficient of correlations of the predicted blast-induced vibration parameters are obtained with respect to the observed field data. The proposed empirical model for PPV has also been compared with the empirical models available for blast vibrations predictions given by other researchers and found to be in good agreement with specific cases.

  6. Coseismic Gravity and Displacement Signatures Induced by the 2013 Okhotsk Mw8.3 Earthquake

    Science.gov (United States)

    Zhang, Guoqing; Shen, Wenbin; Xu, Changyi; Zhu, Yiqing

    2016-01-01

    In this study, Gravity Recovery and Climate Experiment (GRACE) RL05 data from January 2003 to October 2014 were used to extract the coseismic gravity changes induced by the 24 May 2013 Okhotsk Mw8.3 deep-focus earthquake using the difference and least square fitting methods. The gravity changes obtained from GRACE data agreed well with those from dislocation theory in both magnitude and spatial pattern. Positive and negative gravity changes appeared on both sides of the epicenter. The positive signature appeared on the western side, and the peak value was approximately 0.4 microgal (1 microgal = 10−8 m/s2), whereas on the eastern side, the gravity signature was negative, and the peak value was approximately −1.1 microgal. It demonstrates that deep-focus earthquakes Mw ≤ 8.5 are detectable by GRACE observations. Moreover, the coseismic displacements of 20 Global Positioning System (GPS) stations on the Earth’s surface were simulated using an elastic dislocation theory in a spherical earth model, and the results are consistent with the GPS results, especially the near-field results. We also estimated the gravity contributions from the coseismic vertical displacements and density changes, analyzed the proportion of these two gravity change factors (based on an elastic dislocation theory in a spherical earth model) in this deep-focus earthquake. The gravity effect from vertical displacement is four times larger than that caused by density redistribution. PMID:27598158

  7. On the dual nature of lichen-induced rock surface weathering in contrasting micro-environments.

    Science.gov (United States)

    Marques, Joana; Gonçalves, João; Oliveira, Cláudia; Favero-Longo, Sergio E; Paz-Bermúdez, Graciela; Almeida, Rubim; Prieto, Beatriz

    2016-10-01

    Contradictory evidence from biogeomorphological studies has increased the debate on the extent of lichen contribution to differential rock surface weathering in both natural and cultural settings. This study, undertaken in Côa Valley Archaeological Park, aimed at evaluating the effect of rock surface orientation on the weathering ability of dominant lichens. Hyphal penetration and oxalate formation at the lichen-rock interface were evaluated as proxies of physical and chemical weathering, respectively. A new protocol of pixel-based supervised image classification for the analysis of periodic acid-Schiff stained cross-sections of colonized schist revealed that hyphal spread of individual species was not influenced by surface orientation. However, hyphal spread was significantly higher in species dominant on northwest facing surfaces. An apparently opposite effect was noticed in terms of calcium oxalate accumulation at the lichen-rock interface; it was detected by Raman spectroscopy and complementary X-ray microdiffraction on southeast facing surfaces only. These results suggest that lichen-induced physical weathering may be most severe on northwest facing surfaces by means of an indirect effect of surface orientation on species abundance, and thus dependent on the species, whereas lichen-induced chemical weathering is apparently higher on southeast facing surfaces and dependent on micro-environmental conditions, giving only weak support to the hypothesis that lichens are responsible for the currently observed pattern of rock-art distribution in Côa Valley. Assumptions about the drivers of open-air rock-art distribution patterns elsewhere should also consider the micro-environmental controls of lichen-induced weathering, to avoid biased measures of lichen contribution to rock-art deterioration.

  8. Source processes of industrially-induced earthquakes at the Geysers geothermal area, California

    Science.gov (United States)

    Ross, A.; Foulger, G.R.; Julian, B.R.

    1999-01-01

    Microearthquake activity at The Geysers geothermal area, California, mirrors the steam production rate, suggesting that the earthquakes are industrially induced. A 15-station network of digital, three-component seismic stations was operated for one month in 1991, and 3,900 earthquakes were recorded. Highly-accurate moment tensors were derived for 30 of the best recorded earthquakes by tracing rays through tomographically derived 3-D VP and VP / VS structures, and inverting P-and S-wave polarities and amplitude ratios. The orientations of the P-and T-axes are very scattered, suggesting that there is no strong, systematic deviatoric stress field in the reservoir, which could explain why the earthquakes are not large. Most of the events had significant non-double-couple (non-DC) components in their source mechanisms with volumetric components up to ???30% of the total moment. Explosive and implosive sources were observed in approximately equal numbers, and must be caused by cavity creation (or expansion) and collapse. It is likely that there is a causal relationship between these processes and fluid reinjection and steam withdrawal. Compensated linear vector dipole (CLVD) components were up to 100% of the deviatoric component. Combinations of opening cracks and shear faults cannot explain all the observations, and rapid fluid flow may also be involved. The pattern of non-DC failure at The Geysers contrasts with that of the Hengill-Grensdalur area in Iceland, a largely unexploited water-dominated field in an extensional stress regime. These differences are poorly understood but may be linked to the contrasting regional stress regimes and the industrial exploitation at The Geysers.

  9. Intense fracturation induced by mineral growth in porous rocks

    Science.gov (United States)

    Renard, F.; Noiriel, C.; Gratier, J.-P.; Doan, M.-L.

    2009-04-01

    When minerals precipitate in the pores of a rock, they may exert a force that depends on the supersaturation of the fluid; this is the so-called force of crystallization. This process happens in a wide range of geological systems, e.g. vein formation in deep crust, frost heave in soils, and salt damage in cultural heritage monuments. Sometimes, the force of crystallization is so large that it leads to a permanent damage and fracturation of the porous medium. Here, we have studied this process experimentally and imaged in 3D how an intense fracture pattern may emerge from purely chemical processes. Core samples of limestone (22% porosity) and sandstones (19% porosity) were left for one month in contact with an aqueous solution saturated with sodium chloride in an autoclave, at 40°C, under a normal stress in the range 0.2-0.3 MPa. The fluid was allowed to rise in the core samples by capillary forces, up to a height where evaporation occurred. The samples were left in a rubber jacket with the same height as the capillary fringe, allowing therefore an accurate control of the region of water evaporation and salt precipitation. The uniaxial deformation of the samples was measured using high resolution displacement sensors. After the experiments we have imaged the samples in three dimensions, using laboratory computed X-ray tomography, allowing therefore imaging the intensity and localization of the damage, as well as the regions of salt precipitation. During the initial fluid capillary rise, the deformation measurements indicate a small shortening of the samples (~5 micrometers), and then an increase of the samples' height (50-100 micrometers) during salt precipitation. Two kinds of damage could be observed in tomography. Firstly, small rock fragments were pealed from the sample surface. Secondly, and more interestingly, a radial fracture network developed, by nucleation of microcracks at the interface where evaporation occurred, and propagation to the free surface. Two

  10. Numerical model of the glacially-induced intraplate earthquakes and faults formation

    Science.gov (United States)

    Petrunin, Alexey; Schmeling, Harro

    2016-04-01

    According to the plate tectonics, main earthquakes are caused by moving lithospheric plates and are located mainly at plate boundaries. However, some of significant seismic events may be located far away from these active areas. The nature of the intraplate earthquakes remains unclear. It is assumed, that the triggering of seismicity in the eastern Canada and northern Europe might be a result of the glacier retreat during a glacial-interglacial cycle (GIC). Previous numerical models show that the impact of the glacial loading and following isostatic adjustment is able to trigger seismicity in pre-existing faults, especially during deglaciation stage. However this models do not explain strong glaciation-induced historical earthquakes (M5-M7). Moreover, numerous studies report connection of the location and age of major faults in the regions undergone by glaciation during last glacial maximum with the glacier dynamics. This probably imply that the GIC might be a reason for the fault system formation. Our numerical model provides analysis of the strain-stress evolution during the GIC using the finite volume approach realised in the numerical code Lapex 2.5D which is able to operate with large strains and visco-elasto-plastic rheology. To simulate self-organizing faults, the damage rheology model is implemented within the code that makes possible not only visualize faulting but also estimate energy release during the seismic cycle. The modeling domain includes two-layered crust, lithospheric mantle and the asthenosphere that makes possible simulating elasto-plastic response of the lithosphere to the glaciation-induced loading (unloading) and viscous isostatic adjustment. We have considered three scenarios for the model: horizontal extension, compression and fixed boundary conditions. Modeling results generally confirm suppressing seismic activity during glaciation phases whereas retreat of a glacier triggers earthquakes for several thousand years. Tip of the glacier

  11. Spatial Distribution of Ground water Level Changes Induced by the 2006 Hengchun Earthquake Doublet

    OpenAIRE

    Yeeping Chia; Jessie J. Chiu; Po-Yu Chung; Ya-Lan Chang; Wen-Chi Lai; Yen-Chun Kuan

    2009-01-01

    Water-level changes were ob served in 107 wells at 67 monitoring stations in the southern coastal plain of Tai wan during the 2006 Mw 7.1 Hengchun earthquake doublet. Two consecutive coseismic changes induced by the earth quake doublet can be observed from high-frequency data. Obervations from multiple-well stations indicate that the magnitude and direction of coseismic change may vary in wells of different depths. Coseismic rises were dominant on the south east side of the costal plain; wher...

  12. An integrated study of physical precursors of failure in relation to earthquake prediction, using large scale rock blocks

    Directory of Open Access Journals (Sweden)

    A. V. Ponomarev

    1999-06-01

    Full Text Available This paper is multi-analysis approach to rock failure using metric size rock samples. The use of large-scale models permits simulation of the seismic process (including internal rupture on several scales and utilization of a dense network for observation of the spatial variations of several physical parameters. The experiments were performed both on solid rock blocks and on concrete blocks with artificial defects, which enabled simulation of internal shear fracture. The number of various precursors appears to rise up to failure, all of them clearly manifest at the stage of a rapid drop in the applied stress (unstable deformation. The experiment suggests that rocks under strain and prior to failure must be characterized by a heterogeneous field of strains. This means that the strain is distributed mosaically, dilatancy does not generate uniformly and areas where it occurs are likely to be structurally mosaic themselves. To reinforce the prediction of micro- and macrofailure, we have realized simultaneous processing of the obtained data, using sophisticated multidimensional orthogonal functions to represent the different precursors. The possibility to identify the early stages of microfailures and to predict the macrofailure by means of statistical complex parameters derived from data on local deformations, acoustic emissions, elastic waves velocities, electric resistivity and self electric potentials is shown. Despite a considerable dissimilarity in mechanical properties of granite basalt and concrete, the complex parameter proves morphologically identical. Parameter S1 reveals exponential rise up to failure in all cases, and parameter S2 is bay-shaped in form, which makes it more promising in terms of prognosis.

  13. Tsunamigenic, earthquake-triggered rock slope failures during the April 21, 2007 Aisén earthquake, southern Chile (45.5°S Inestabilidades de laderas de roca generadoras de tsunami durante el terremoto de Aisén del 21 de abril de 2007, sur de Chile (45.5° S

    Directory of Open Access Journals (Sweden)

    Sergio A Sepúlveda

    2009-01-01

    Full Text Available The April 21, 2007 shallow crustal earthquake (Mw 6.2 in the Aisén Fjord area triggered hundreds of landslides around the epicentral zone. Among those, several rock slope failures such as rock slides, rock falls and rock avalanches were induced on the steep fjord slopes. The violent impact of the disrupted rock masses into the fjord generated local tsunamis that caused ten fatalities and extensive damage to salmón farms located along the fjord shores. Field observations suggested that geotechnical and geomorphological factors controlled the landslide locations and failure modes, associated with the presence of faults and topographic relief, respectively. This event is an example of a geological hazard that has not been previously addressed in the Chilean Patagonian fjordland, revealing the need for identifying and understanding these geological phenomena in future hazard assessments in the región.El 21 de abril de 2007 un terremoto superficial cortical (Mw 6,2 en el área del Fiordo Aisén desencadenó cientos de remociones en masa en la zona epicentral. Entre éstas, se generaron varias inestabilidades en laderas rocosas escarpadas, tales como deslizamientos, caídas y avalanchas de rocas. El violento impacto de las masas disgregadas de roca en las aguas del fiordo generó tsunamis locales, que causaron diez víctimas fatales y un importante daño en granjas salmoneras ubicadas a lo largo de las costas del fiordo. Observaciones de terreno sugieren controles geotécnicos y geomorfológicos en la ubicación y modos de falla de las remociones en masa, asociados a la presencia de fallas y relieve abrupto, respectivamente. Este evento es un ejemplo de un tipo de peligro geológico que no ha sido previamente detectado ni abordado en los fiordos de la Patagonia Chilena, revelando la necesidad de identificar y comprender estos fenómenos geológicos en futuras evaluaciones de peligro en la región.

  14. Experimental investigation of fundamental processes in mining induced fracturing and rock instability.

    CSIR Research Space (South Africa)

    Napier, JAL

    2002-03-01

    Full Text Available Final Report Experimental investigation of fundamental processes in mining induced fracturing and rock instability J.A.L. Napier, K. Drescher, M.W. Hildyard, M.O. Kataka, D.F. Malan, E.J. Sellers Research Agency : CSIR Miningtek Project No : GAP...

  15. Earthquake induced landslide hazard: a multidisciplinary field observatory in the Marmara SUPERSITE

    Science.gov (United States)

    Bigarré, Pascal

    2014-05-01

    Earthquake-triggered landslides have an increasing disastrous impact in seismic regions due to the fast growing urbanization and infrastructures. Just considering disasters from the last fifteen years, among which the 1999 Chi-Chi earthquake, the 2008 Wenchuan earthquake, and the 2011 Tohoku earthquake, these events generated tens of thousands of coseismic landslides. Those resulted in amazing death toll and considerable damages, affecting the regional landscape including its hydrological main features. Despite a strong impetus in research during past decades, knowledge on those geohazards is still fragmentary, while databases of high quality observational data are lacking. These phenomena call for further collaborative researches aiming eventually to enhance preparedness and crisis management. As one of the three SUPERSITE concept FP7 projects dealing with long term high level monitoring of major natural hazards at the European level, the MARSITE project gathers research groups in a comprehensive monitoring activity developed in the Sea of Marmara Region, one of the most densely populated parts of Europe and rated at high seismic risk level since the 1999 Izmit and Duzce devastating earthquakes. Besides the seismic threat, landslides in Turkey and in this region constitute an important source of loss. The 1999 Earthquake caused extensive landslides while tsunami effects were observed during the post-event surveys in several places along the coasts of the Izmit bay. The 6th Work Package of MARSITE project gathers 9 research groups to study earthquake-induced landslides focusing on two sub-regional areas of high interest. First, the Cekmece-Avcilar peninsula, located westwards of Istanbul, is a highly urbanized concentrated landslide prone area, showing high susceptibility to both rainfalls while affected by very significant seismic site effects. Second, the off-shore entrance of the Izmit Gulf, close to the termination of the surface rupture of the 1999 earthquake

  16. [High Precision Identification of Igneous Rock Lithology by Laser Induced Breakdown Spectroscopy].

    Science.gov (United States)

    Wang, Chao; Zhang, Wei-gang; Yan, Zhi-quan

    2015-09-01

    In the field of petroleum exploration, lithology identification of finely cuttings sample, especially high precision identification of igneous rock with similar property, has become one of the geological problems. In order to solve this problem, a new method is proposed based on element analysis of Laser-Induced Breakdown Spectroscopy (LIBS) and Total Alkali versus Silica (TAS) diagram. Using independent LIBS system, factors influencing spectral signal, such as pulse energy, acquisition time delay, spectrum acquisition method and pre-ablation are researched through contrast experiments systematically. The best analysis conditions of igneous rock are determined: pulse energy is 50 mJ, acquisition time delay is 2 μs, the analysis result is integral average of 20 different points of sample's surface, and pre-ablation has been proved not suitable for igneous rock sample by experiment. The repeatability of spectral data is improved effectively. Characteristic lines of 7 elements (Na, Mg, Al, Si, K, Ca, Fe) commonly used for lithology identification of igneous rock are determined, and igneous rock samples of different lithology are analyzed and compared. Calibration curves of Na, K, Si are generated by using national standard series of rock samples, and all the linearly dependent coefficients are greater than 0.9. The accuracy of quantitative analysis is investigated by national standard samples. Element content of igneous rock is analyzed quantitatively by calibration curve, and its lithology is identified accurately by the method of TAS diagram, whose accuracy rate is 90.7%. The study indicates that LIBS can effectively achieve the high precision identification of the lithology of igneous rock.

  17. Rock fragments induce patchy distribution of soil water repellency in burned soils

    Science.gov (United States)

    Gordillo-Rivero, Ángel; García-Moreno, Jorge; Bárcenas-Moreno, Gema; Jiménez-Morillo, Nicasio T.; Mataix-Solera, Jorge; Jordán, Antonio; Zavala, Lorena M.

    2013-04-01

    Forest fires are recurrent phenomena in the Mediterranean area and are one of the main causes of changes in the Mediterranean ecosystems, increasing the risk of soil erosion and desertification. Fire is an important agent which can induce important changes in the chemical and physical characteristics of soils. During wildfires, only a small part of the heat generated is transmitted to the first centimetres of the soil profile. The intensity of the changes produced in the physical and chemical characteristics of the soil depends on the temperatures reached at different soil depths, the time of residence of temperature peaks, and the stability of the different soil components. One of the soil physical properties strongly affected by fire is soil water repellency (WR). Depending on temperature, time of heating, type of soil and fuel, fire can induce, enhance or destroy soil WR. Soil WR is a key factor in controlling soil hydrology and water availability in burnt soils together with other factors as texture or aggregation. Although the occurrence and consequences of fire-induced soil WR have been deeply studied, some gaps still exist, as the influence of rock fragment cover during burning. During combustion of litter and aerial biomass, the soil surface under rock fragments is heated and reachs temperature peaks after a certain delay respect to exposed areas. In contrast, temperature peaks are longer, increasing the time of residence of high temperature. In consequence, rock fragments may change the expected spatial distribution of soil WR. Up to date, very scarce research concerns the effect of rock fragments at the soil surface on the fire-induced pattern of soil water repellency. METHODS Two experiments were carried out in this research. In the first case, an experiment was conducted in an experimental farm in Sevilla (southern Spain). The effect of a low severity prescribed fire was studied in soil plots under different rock fragment covers (0, 15, 30, 45 and 60

  18. 2017 One‐year seismic‐hazard forecast for the central and eastern United States from induced and natural earthquakes

    Science.gov (United States)

    Petersen, Mark D.; Mueller, Charles; Moschetti, Morgan P.; Hoover, Susan M.; Shumway, Allison; McNamara, Daniel E.; Williams, Robert; Llenos, Andrea L.; Ellsworth, William L; Rubinstein, Justin L.; McGarr, Arthur F.; Rukstales, Kenneth S.

    2017-01-01

    We produce a one‐year 2017 seismic‐hazard forecast for the central and eastern United States from induced and natural earthquakes that updates the 2016 one‐year forecast; this map is intended to provide information to the public and to facilitate the development of induced seismicity forecasting models, methods, and data. The 2017 hazard model applies the same methodology and input logic tree as the 2016 forecast, but with an updated earthquake catalog. We also evaluate the 2016 seismic‐hazard forecast to improve future assessments. The 2016 forecast indicated high seismic hazard (greater than 1% probability of potentially damaging ground shaking in one year) in five focus areas: Oklahoma–Kansas, the Raton basin (Colorado/New Mexico border), north Texas, north Arkansas, and the New Madrid Seismic Zone. During 2016, several damaging induced earthquakes occurred in Oklahoma within the highest hazard region of the 2016 forecast; all of the 21 moment magnitude (M) ≥4 and 3 M≥5 earthquakes occurred within the highest hazard area in the 2016 forecast. Outside the Oklahoma–Kansas focus area, two earthquakes with M≥4 occurred near Trinidad, Colorado (in the Raton basin focus area), but no earthquakes with M≥2.7 were observed in the north Texas or north Arkansas focus areas. Several observations of damaging ground‐shaking levels were also recorded in the highest hazard region of Oklahoma. The 2017 forecasted seismic rates are lower in regions of induced activity due to lower rates of earthquakes in 2016 compared with 2015, which may be related to decreased wastewater injection caused by regulatory actions or by a decrease in unconventional oil and gas production. Nevertheless, the 2017 forecasted hazard is still significantly elevated in Oklahoma compared to the hazard calculated from seismicity before 2009.

  19. 2017 one-year seismic hazard forecast for the central and eastern United States from induced and natural earthquakes

    Science.gov (United States)

    Petersen, Mark D.; Mueller, Charles; Moschetti, Morgan P.; Hoover, Susan M.; Shumway, Allison; McNamara, Daniel E.; Williams, Robert A.; Llenos, Andrea L.; Ellsworth, William L.; Michael, Andrew J.; Rubinstein, Justin L.; McGarr, Arthur F.; Rukstales, Kenneth S.

    2017-01-01

    We produce the 2017 one-year seismic hazard forecast for the central and eastern United States from induced and natural earthquakes that updates the 2016 one-year forecast; this map is intended to provide information to the public and to facilitate the development of induced seismicity forecasting models, methods, and data. The 2017 hazard model applies the same methodology and input logic tree as the 2016 forecast, but with an updated earthquake catalog. We also evaluate the 2016 seismic hazard forecast to improve future assessments. The 2016 forecast indicated high seismic hazard (greater than 1% probability of potentially damaging ground shaking in one-year) in five focus areas: Oklahoma-Kansas, the Raton Basin (Colorado/New Mexico border), north Texas, north Arkansas, and the New Madrid Seismic Zone. During 2016, several damaging induced earthquakes occurred in Oklahoma within the highest hazard region of the 2016 forecast; all of the 21 magnitude (M) ≥ 4 and three M ≥ 5 earthquakes occurred within the highest hazard area in the 2016 forecast. Outside the Oklahoma-Kansas focus area two earthquakes with M ≥ 4 occurred near Trinidad, Colorado (in the Raton Basin focus area), but no earthquakes with M ≥ 2.7 were observed in the north Texas or north Arkansas focus areas. Several observations of damaging ground shaking levels were also recorded in the highest hazard region of Oklahoma. The 2017 forecasted seismic rates are lower in regions of induced activity due to lower rates of earthquakes in 2016 compared to 2015, which may be related to decreased wastewater injection, caused by regulatory actions or by a decrease in unconventional oil and gas production. Nevertheless, the 2017 forecasted hazard is still significantly elevated in Oklahoma compared to the hazard calculated from seismicity before 2009.

  20. PEG-PEI/siROCK2 Protects Against Aβ42-Induced Neurotoxicity in Primary Neuron Cells for Alzheimer Disease.

    Science.gov (United States)

    Liu, Yunyun; Yang, Xingyi; Lei, Qingfeng; Li, Zhong; Hu, Jingyang; Wen, Xiaojun; Wang, Huijun; Liu, Zhonglin

    2015-08-01

    Gene therapy that targets the ROCK2 gene has yielded promising results in the treatment of AD. Our previous study indicated that PEG-PEI/siROCK2 could effectively suppress ROCK2 mRNA expression and showed a promising prospect for the treatment of Alzheimer's disease. However, the ability of PEG-PEI/siROCK2 to reduce Aβ-induced cytotoxicity is unknown. To investigate the effect of PEG-PEI/siROCK2 against Aβ42-induced neurotoxicity, primary cultured cortical neurons were pretreated with PEG-PEI/siROCK2 for 24 h and then treated with 5 μM Aβ42 for 24 h. We found that PEG-PEI/siROCK2 increased the cell viability and reduced the number of apoptotic cells induced by Aβ42, as measured using an MTT assay and Annexin V/PI staining. A further study revealed that PEG-PEI/siROCK2 can activate p-Akt, and treatment with the PI3K inhibitor LY294002 attenuated the neuroprotective effects. These results suggest that PEG-PEI/siROCK2 prevents Aβ42-induced neurotoxicity and that the activation of PI3K/Akt pathway is involved in neuroprotection. Taken together, these findings shed light on the role of PEG-PEI/siROCK2 as a potential therapeutic agent for AD.

  1. In vivo Effects in Melanoma of ROCK Inhibition-Induced FasL Overexpression.

    Science.gov (United States)

    Teiti, Iotefa; Florie, Bertrand; Pich, Christine; Gence, Rémi; Lajoie-Mazenc, Isabelle; Rochaix, Philippe; Favre, Gilles; Tilkin-Mariamé, Anne-Françoise

    2015-01-01

    Ectopic Fas-ligand (FasL) expression in tumor cells is responsible for both tumor escape through tumor counterattack of Fas-positive infiltrating lymphocytes and tumor rejection though inflammatory and immune responses. We have previously shown that RhoA GTPase and its effector ROCK negatively control FasL membrane expression in murine melanoma B16F10 cells. In this study, we found that B16F10 treatment with the ROCK inhibitor H1152 reduced melanoma development in vivo through FasL membrane overexpression. Although H1152 treatment did not reduce tumor growth in vitro, pretreatment of tumor cells with this inhibitor delayed tumor appearance, and slowed tumor growth in C57BL/6 immunocompetent mice. Thanks to the use of mice-bearing mutated Fas receptors (B6/lpr), we found that reduced tumor growth, observed in immunocompetent mice, was linked to FasL overexpression induced by H1152 treatment. Tumor growth analysis in immunosuppressed NUDE and IFN-γ-KO mice highlighted major roles for T lymphocytes and IFN-γ in the H1152-induced tumor growth reduction. Histological analyses of subcutaneous tumors, obtained from untreated versus H1152-treated B16F10 cells, showed that H1152 pretreatment induced a strong intratumoral infiltration of leukocytes. Cytofluorometric analysis showed that among these leukocytes, the number of activated CD8 lymphocytes was increased. Moreover, their antibody-induced depletion highlighted their main responsibility in tumor growth reduction. Subcutaneous tumor growth was also reduced by repeated intravenous injections of a clinical ROCK inhibitor, Fasudil. Finally, H1152-induced ROCK inhibition also reduced pulmonary metastasis implantation independently of T cell-mediated immune response. Altogether, our data suggest that ROCK inhibitors could become interesting pharmacological molecules for melanoma immunotherapy.

  2. High‐frequency induced polarization measurements of hydrocarbon‐bearing rocks

    DEFF Research Database (Denmark)

    Burtman, Vladimir; Endo, Masashi; Zhdanov, Michael S.

    2011-01-01

    We have investigated induced polarization (IP) effects in hydrocarbon‐bearing artificial rocks at frequencies greater than 100 Hz. We have examined the instrumental and electrode phase responses of Zonge International's complex resistivity (CR) system, and optimized the performance of the Zonge...... system for IP measurements over the 1 mHz to 10 kHz frequency range. The reliability of the high‐frequency IP measurements were confirmed by independent measurement of the same samples using the Novocontrol BDS 80 system. Our results confirm the presence of IP effects in hydrocarbon‐bearing rocks...

  3. A simulation of earthquake induced undrained pore pressure changes with bearing on some soil liquefaction observations following the 2001 Bhuj earthquake

    Indian Academy of Sciences (India)

    Irene Sarkar; Ramesh Chander

    2003-09-01

    The Bhuj earthquake of January 26th, 2001, induced wide spread liquefaction within the Kachch peninsula. It has been pointed out that inundation due to soil liquefaction was short lived in some parts than in others in the affected region. Several geological, seismological and hydrological factors would have cumulatively contributed to these observed changes. We simulate in this article, undrained or short-term change in pore pressure in a poroelastic half space, in response to a simplified model of the Bhuj earthquake source. We find that the regions of relatively shorter lived inundation due to soil liquefaction may fall in the region where pore pressure responsible for soil liquefaction attributable to strong ground shaking was counteracted by pore pressure changes due to undrained poroelastic effect and vice versa.

  4. Clostridium perfringens TpeL Induces Formation of Stress Fibers via Activation of RhoA-ROCK Signaling Pathway.

    Science.gov (United States)

    Nagahama, Masahiro; Ohkubo, Akiko; Kinouchi, Yoshihito; Kobayashi, Keiko; Miyamoto, Kazuaki; Takehara, Masaya; Sakurai, Jun

    2015-01-01

    Clostridium perfringens TpeL belongs to a family of large clostridial glucosylating cytotoxins. TpeL modifies Rac1 and Ras subfamily proteins. Herein we report TpeL-induced formation of stress fibers via RhoA-Rho kinase (ROCK) signaling. A recombinant protein (TpeL1-525) derived from the TpeL N-terminal catalytic domain in the presence of streptolysin O (SLO) induced the formation of actin stress fibers in Madin-Darby canine kidney (MDCK) cells in a dose-dependent manner. The RhoA/ROCK pathway is known to control the formation of stress fibers. We examined the role of the RhoA/ROCK pathway in TpeL-induced formation of stress fibers. TpeL1-525-induced formation of stress fibers was inhibited by the ROCK inhibitor, Y27632 and Rho protein inhibitor, C3 transferase. TpeL1-525 activated RhoA and ROCK in a dose-dependent manner. C3 transferase blocked TpeL1-525-induced activation of RhoA and ROCK whereas Y27632 inhibited TpeL-induced activation of ROCK. These results demonstrate for the first time that TpeL induces the formation of stress fibers by activating the RhoA/ROCK signaling pathway.

  5. Substrate Stiffness Influences Doxorubicin-Induced p53 Activation via ROCK2 Expression

    Directory of Open Access Journals (Sweden)

    Takahiro Ebata

    2017-01-01

    Full Text Available The physical properties of the extracellular matrix (ECM, such as stiffness, are involved in the determination of the characteristics of cancer cells, including chemotherapy sensitivity. Resistance to chemotherapy is often linked to dysfunction of tumor suppressor p53; however, it remains elusive whether the ECM microenvironment interferes with p53 activation in cancer cells. Here, we show that, in MCF-7 breast cancer cells, extracellular stiffness influences p53 activation induced by the antitumor drug doxorubicin. Cell growth inhibition by doxorubicin was increased in response to ECM rigidity in a p53-dependent manner. The expression of Rho-associated coiled coil-containing protein kinase (ROCK 2, which induces the activation of myosin II, was significantly higher when cells were cultured on stiffer ECM substrates. Knockdown of ROCK2 expression or pharmacological inhibition of ROCK decreased doxorubicin-induced p53 activation. Our results suggest that a soft ECM causes downregulation of ROCK2 expression, which drives resistance to chemotherapy by repressing p53 activation.

  6. Measurements of frequency dependent shear wave attenuation in sedimentary basins using induced earthquakes

    Science.gov (United States)

    Richter, Tom; Wegler, Ulrich

    2015-04-01

    Modeling of peak ground velocity caused by induced earthquakes requires detailed knowledge about seismic attenuation properties of the subsurface. Especially shear wave attenuation is important, because shear waves usually show the largest amplitude in high frequency seismograms. We report intrinsic and scattering attenuation coefficients of shear waves near three geothermal reservoirs in Germany for frequencies between 2 Hz and 50 Hz. The geothermal plants are located in the sedimentary basins of the upper Rhine graben (Insheim and Landau) and the Molasse basin (Unterhaching). The method optimizes the fit between Green's functions for the acoustic, isotropic radiative transfer theory and observed energy densities of induced earthquakes. The inversion allows the determination of scattering and intrinsic attenuation, site corrections, and spectral source energies for the investigated frequency bands. We performed the inversion at the three sites for events with a magnitude between 0.7 and 2. We determined a transport mean free path of 70 km for Unterhaching. For Landau and Insheim the transport mean free path depends on frequency. It ranges from 2 km (at 2 Hz) to 30 km (at 40 Hz) for Landau and from 9 km to 50 km for Insheim. The quality factor for intrinsic attenuation is constant for frequencies smaller than 10 Hz at all three sites. It is around 100 for Unterhaching and 200 for Landau and Insheim with higher values above 10 Hz.

  7. Abduction of Toe-excavation Induced Failure Process from LEM and FDM for a Dip Slope with Rock Anchorage in Taiwan

    Science.gov (United States)

    Huang, W.-S.; Lin, M.-L.; Liu, H.-C.; Lin, H.-H.

    2012-04-01

    On April 25, 2010, without rainfall and earthquake triggering a massive landslide (200000 m3) covered a 200m stretch of Taiwan's National Freeway No. 3, killing 4 people, burying three cars and destroying a bridge. The failure mode appears to be a dip-slope type failure occurred on a rock anchorage cut slope. The strike of Tertiary sedimentary strata is northeast-southwest and dip 15˚ toward southeast. Based on the investigations of Taiwan Geotechnical Society, there are three possible factors contributing to the failure mechanism as follow:(1) By toe-excavation during construction in 1998, the daylight of the sliding layer had induced the strength reduction in the sliding layer. It also caused the loadings of anchors increased rapidly and approached to their ultimate capacity; (2) Although the excavated area had stabilized soon with rock anchors and backfills, the weathering and groundwater infiltration caused the strength reduction of overlying rock mass; (3) The possible corrosion and age of the ground anchors deteriorate the loading capacity of rock anchors. Considering the strength of sliding layer had reduced from peak to residual strength which was caused by the disturbance of excavation, the limit equilibrium method (LEM) analysis was utilized in the back analysis at first. The results showed the stability condition of slope approached the critical state (F.S.≈1). The efficiency reduction of rock anchors and strength reduction of overlying stratum (sandstone) had been considered in following analysis. The results showed the unstable condition (F.S. <1). This research also utilized the result of laboratory test, geological strength index(GSI) and finite difference method (FDM, FLAC 5.0) to discuss the failure process with the interaction of disturbance of toe-excavation, weathering of rock mass, groundwater infiltration and efficiency reduction of rock anchors on the stability of slope. The analysis indicated that the incremental load of anchors have

  8. Strains Induced in Urban Structures by Ultra-High Frequency Blasting Rock Motions: A Case Study

    Science.gov (United States)

    Dowding, C. H.; Hamdi, E.; Aimone-Martin, C. T.

    2016-10-01

    This paper describes measurement and interpretation of strains induced in two, multiple story, older, urban structures by ultra-high frequency rock blast excitation from contiguous excavation. These strains are obtained from relative displacements found by integrating time correlated velocity time histories from multiple positions on the structures and foundation rock. Observations are based on ten instrumented positions on the structures and in the foundation rock during eight blast events, which provided over 70 time histories for analysis. The case study and measurements allowed the following conclusions: despite particle velocities in the rock that greatly exceed regulatory limits, strains in external walls are similar to or lower than those necessary to crack masonry structures and weak wall covering materials. These strains are also lower than those sustained by single story residential structures when excited by low frequency motions with particle velocities below regulatory limits. Expected relative displacements calculated with pseudo velocity single degree of freedom response spectra of excitation motions measured in the rock are similar to those measured.

  9. Rho/ROCK signal cascade mediates asymmetric dimethylarginine-induced vascular smooth muscle cells migration and phenotype change.

    Science.gov (United States)

    Zhou, Yi-ming; Lan, Xi; Guo, Han-bin; Zhang, Yan; Ma, Li; Cao, Jian-biao

    2014-01-01

    Asymmetric dimethylarginine (ADMA) induces vascular smooth muscle cells (VSMCs) migration. VSMC phenotype change is a prerequisite of migration. RhoA and Rho-kinase (ROCK) mediate migration of VSMCs. We hypothesize that ADMA induces VSMC migration via the activation of Rho/ROCK signal pathway and due to VSMCs phenotype change. ADMA activates Rho/ROCK signal pathway that interpreted by the elevation of RhoA activity and phosphorylation level of a ROCK substrate. Pretreatment with ROCK inhibitor, Y27632 completely reverses the induction of ADMA on ROCK and in turn inhibits ADMA-induced VSMCs migration. When the Rho/ROCK signal pathway has been blocked by pretreatment with Y27632, the induction of ERK signal pathway by ADMA is completely abrogated. Elimination of ADMA via overexpression of dimethylarginine dimethylaminohydrolase 2 (DDAH2) and L-arginine both blocks the effects of ADMA on the activation of Rho/ROCK and extra cellular signal-regulated kinase (ERK) in VSMCs. The expression of differentiated phenotype relative proteins was reduced and the actin cytoskeleton was disassembled by ADMA, which were blocked by Y27632, further interpreting that ADMA inducing VSMCs migration via Rho/ROCK signal pathway is due to its effect on the VSMCs phenotype change. Our present study may help to provide novel insights into the therapy and prevention of atherosclerosis.

  10. Gravity-induced rock mass damage related to large en masse rockslides: Evidence from Vajont

    Science.gov (United States)

    Paronuzzi, Paolo; Bolla, Alberto

    2015-04-01

    The Vajont landslide is a well-known, reservoir-induced slope failure that occurred on 9 October 1963 and was characterized by an 'en masse' sliding motion that triggered various large waves, determining catastrophic consequences for the nearby territory and adjacent villages. During the Vajont dam construction, and especially after the disaster, some researchers identified widespread field evidence of heavy rock mass damage involving the presumed prehistoric rockslide and/or the 1963 failed mass. This paper describes evidence of heavy gravitational damage, including (i) folding, (ii) fracturing, (iii) faulting, and (iv) intact rock disintegration. The gravity-induced rock mass damage (GRMD) characterizes the remnants of the basal shear zone, still resting on the large detachment surface, and the 1963 failed rock mass. The comprehensive geological study of the 1963 Vajont landslide, based on the recently performed geomechanical survey (2006-present) and on the critical analysis of the past photographic documentation (1959-1964), allows us to recognize that most GRMD evidence is related to the prehistoric multistage Mt. Toc rockslide. The 1963 catastrophic en masse remobilization induced an increase to the prehistoric damage, reworking preexisting structures and creating additional gravity-driven features (folds, fractures, faults, and rock fragmentation). The gravity-induced damage was formed during the slope instability phases that preceded the collapse (static or quasi-static GRMD) and also as a consequence of the sliding motion and of the devastating impact between the failed blocks (dynamic GRMD). Gravitational damage originated various types of small drag folds such as flexures, concentric folds, chevron, and kink-box folds, all having a radius of 1-5 m. Large buckle folds (radius of 10-50 m) are related to the dynamic damage and were formed during the en masse motion as a consequence of deceleration and impact processes that involved the sliding mass. Prior

  11. Experimental Exploration on Rainfall-induced Mass Re-mobilization after Giant Earthquake: A case study in Wenchuan earthquake hit region, China

    Science.gov (United States)

    Yang, Zongji; Bogaard, Thom. A.; Qiao, Jianping; Jiang, Yuanjun

    2015-04-01

    Prevention and mitigation of rainfall induced geological hazards after the Ms=8 Wenchuan earthquake on May 12th, 2008 were gained more significance for the rebuild of earthquake hit regions in China. After the Wenchuan earthquake, there were thousands of slopes failure, which were much more susceptible to subsequent heavy rainfall and many even transformed into potential debris flows. An typical example can be found in the catastrophic disaster occurred in Zhongxing County, Chengdu City on 10th July, 2013 in which the unknown fractured slope up the mountain was triggered by a downpour and transformed into subsequent debris flow which wiped the community downstream, about 200 victims were reported in that tragic event. The transform patterns of rainfall-induced mass re-mobilization was categorized into three major type as the erosion of fractured slopes, initiate on loosen deposit and outbreak of landslide (debris flow) dams according to vast field investigation in the earthquake hit region. Despite the widespread and hidden characters,the complexity of the process also demonstrated in the transforms of the mass re-mobilized by the erosion of both gravity and streams in the small watersheds which have never been reported before the giant Wenchuan Earthquake in many regions. As a result, an increasing number of questions for disaster relief and mitigation were proposed including the threshold of early warning and measurement of the volume for the design of mitigation measures on rainfall-induced mass re-mobilization in debris flow gullies. This study is aimed for answer the essential questions about the threshold and amount of mass initiation triggered by the subsequent rainfall in post earthquake time. In this study, experimental tests were carried out for simulating the failure of the rainfall-induced mass re-mobilization in respectively in a natural co-seismic fractured slope outside and the debris flow simulation platform inside the laboratory. A natural

  12. Role of induced electrical polarization to identify soft ground/fractured rock conditions

    Science.gov (United States)

    Park, Jinho; Lee, Kang-Hyun; Seo, Hyungjoon; Ryu, Jinwoo; Lee, In-Mo

    2017-02-01

    This study attempted to evaluate the role and effectiveness of induced polarization (IP) along with electrical resistivity to identify soft ground/fractured rock. Theoretical studies as well as laboratory-scale experiments were conducted for this purpose. The theoretical study involved deriving the functional relationship between chargeability and influential variables. This was followed by performing a sensitivity analysis using the derived relationship to reveal that the size of narrow pores (r1) exerted the greatest influence on the chargeability followed by the salinity of the pore water (C0). In the laboratory test, a small-scale fractured rock zone was modeled using sandstone as a parent rock. The chargeability and resistivity were measured by changing the size of the joint aperture filled with tap water and/or sea water, the location of the fractured zone, and the thickness of the soil layer in a soil-rock multi-layered ground. The experimental study modeled the jointed zone between competent sandstone layers and indicated that the chargeability was mostly controlled by the size of the narrow pore (r1) of the surface sandstone and not by the porosity of the jointed zone. Hence, it was concluded that the chargeability did not significantly depend on the fractured characteristics of the jointed rock. It could be difficult to clearly distinguish as to whether the low resistivity value is caused by the sea water intrusion or by the increase in porosity of the fractured ground. However, the IP exploration can be effectively utilized to identify sea water intrusion since the chargeability decreased as the salinity of pore water increased. The experimental study on a soil-rock multi-layered ground indicated that the measured chargeability was controlled by the percentage of current flow that passed through the competent rock as well as by the narrow pore size of the rock itself. In conclusion, the ground condition could be easily identified by measuring the IP in

  13. Segmentation and Classification of Nepal Earthquake Induced Landslides Using SENTINEL-1 Product

    Science.gov (United States)

    Kunwar, Saket

    2016-06-01

    On April 26, 2015, an earthquake of magnitude 7.8 on the Richter scale occurred, with epicentre at Barpak (28°12'20''N,84°44'19''E), Nepal. Landslides induced due to the earthquake and its aftershock added to the natural disaster claiming more than 9000 lives. Landslides represented as lines that extend from the head scarp to the toe of the deposit were mapped by the staff of the British Geological Survey and is available freely under Open Data Commons Open Database License(ODC-ODbL) license at the Humanitarian Data Exchange Program. This collection of 5578 landslides is used as preliminary ground truth in this study with the aim of producing polygonal delineation of the landslides from the polylines via object oriented segmentation. Texture measures from Sentinel-1a Ground Range Detected (GRD) Amplitude data and eigenvalue-decomposed Single Look Complex (SLC) polarimetry product are stacked for this purpose. This has also enabled the investigation of landslide properties in the H-Alpha plane, while developing a classification mechanism for identifying the occurrence of landslides.

  14. Land cover changes induced by the great east Japan earthquake in 2011

    Science.gov (United States)

    Ishihara, Mitsunori; Tadono, Takeo

    2017-03-01

    The east Japan earthquake that occurred on March 11, 2011 was a big natural disaster, comprising the large earthquake shock, tsunami, and Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. These disasters caused changes in the land use and land cover (LULC) in Japan’s Tohoku district. While the LULC map created before the disaster is available, as yet there is no precise LULC map of the district after the disaster. In this study, we created a precise LULC map for the years 2013-2015 post-disaster with 30-m spatial resolution using the Landsat-8 with the Operational Land Imager (OLI) to evaluate the changes in LULC induced by the disaster. Our results indicate many changes in areas categorized as rice paddies primarily into grass categories along the coast damaged by the tsunami and in the evacuation zone around the FDNPP. Since there is a possibility of future LULC changes according to the change of the evacuation zone and implementation of reconstruction and revitalization efforts, we recommend continual monitoring of the changes in LULC by the use of satellite data in order to evaluate the long-term effects of the disaster.

  15. Seismotectonic Condition of Reservoirs Inferred from Magnitudes of Injection-Induced Earthquakes

    Science.gov (United States)

    Dinske, C.; Shapiro, S. A.

    2011-12-01

    Hydraulic stimulation operations aimed to enhance the permeability of reservoirs induce fracture shear slippage and fracture dilatation. A potential hazard of the injection-induced seismic activity has so far received less consideration. The hydraulic stimulation of the Basel geothermal reservoir in 2006, however, caused several significant events which were felt by the population (Majer et al., 2007, Häring et al., 2008) leading to the suspension of the project. It had revealed that a more in-depth knowledge regarding the seismic hazard associated with fluid injections is required. A key point for evaluating the seismic hazard is to identify the parameters which define the earthquake magnitude and its frequency. Recently, it was shown that under rather general conditions the probability of a seismic event having a magnitude larger than a given one increases proportionally to the injected fluid mass (Shapiro et al., 2007, Shapiro and Dinske, 2009). The number of earthquakes larger than a given magnitude also depends on the seismotectonic conditions of an injection site. A convenient parameter for the characterization of these conditions is the seismogenic index Σ (Shapiro et al., 2010). It combines four, generally unknown, site-specific seismotectonic quantities. In this study, we continue to comparatively analyze the seismotectonic state of several geothermal as well as non-geothermal reservoir locations using this index. Here we compute the seismogenic index at 8 different reservoir locations (and 15 different injection experiments). We show that the seismogenic index is nearly time-independent. It is clear from our analysis that the seismogenic index has a characteristic range of values for geothermal reservoirs on the one hand, [-4 law are known for a specific location (for instance, from a preceding, short-term injection), then our formalism allows to compute the expected number of induced earthquakes having a magnitude larger than a given one for a known

  16. Effects of wing locations on wing rock induced by forebody vortices

    Directory of Open Access Journals (Sweden)

    Ma Baofeng

    2016-10-01

    Full Text Available Previous studies have shown that asymmetric vortex wakes over slender bodies exhibit a multi-vortex structure with an alternate arrangement along a body axis at high angle of attack. In this investigation, the effects of wing locations along a body axis on wing rock induced by forebody vortices was studied experimentally at a subcritical Reynolds number based on a body diameter. An artificial perturbation was added onto the nose tip to fix the orientations of forebody vortices. Particle image velocimetry was used to identify flow patterns of forebody vortices in static situations, and time histories of wing rock were obtained using a free-to-roll rig. The results show that the wing locations can affect significantly the motion patterns of wing rock owing to the variation of multi-vortex patterns of forebody vortices. As the wing locations make the forebody vortices a two-vortex pattern, the wing body exhibits regularly divergence and fixed-point motion with azimuthal variations of the tip perturbation. If a three-vortex pattern exists over the wing, however, the wing-rock patterns depend on the impact of the highest vortex and newborn vortex. As the three vortices together influence the wing flow, wing-rock patterns exhibit regularly fixed-points and limit-cycled oscillations. With the wing moving backwards, the newborn vortex becomes stronger, and wing-rock patterns become fixed-points, chaotic oscillations, and limit-cycled oscillations. With further backward movement of wings, the vortices are far away from the upper surface of wings, and the motions exhibit divergence, limit-cycled oscillations and fixed-points. For the rearmost location of the wing, the wing body exhibits stochastic oscillations and fixed-points.

  17. LPA Induces Colon Cancer Cell Proliferation through a Cooperation between the ROCK and STAT-3 Pathways

    Science.gov (United States)

    Leve, Fernanda; Peres-Moreira, Rubem J.; Binato, Renata; Abdelhay, Eliana; Morgado-Díaz, José A.

    2015-01-01

    Lysophosphatidic acid (LPA) plays a critical role in the proliferation and migration of colon cancer cells; however, the downstream signaling events underlying these processes remain poorly characterized. The aim of this study was to investigate the signaling pathways triggered by LPA to regulate the mechanisms involved in the progression of colorectal cancer (CRC). We have used three cell line models of CRC, and initially analyzed the expression profile of LPA receptors (LPAR). Then, we treated the cells with LPA and events related to their tumorigenic potential, such as migration, invasion, anchorage-independent growth, proliferation as well as apoptosis and cell cycle were evaluated. We used the Chip array technique to analyze the global gene expression profiling that occurs after LPA treatment, and we identified cell signaling pathways related to the cell cycle. The inhibition of these pathways verified the conclusions of the transcriptomic analysis. We found that the cell lines expressed LPAR1, -2 and -3 in a differential manner and that 10 μM LPA did not affect cell migration, invasion and anchorage-independent growth, but it did induce proliferation and cell cycle progression in HCT-116 cells. Although LPA in this concentration did not induce transcriptional activity of β-catenin, it promoted the activation of Rho and STAT-3. Moreover, ROCK and STAT-3 inhibitors prevented LPA-induced proliferation, but ROCK inhibition did not prevent STAT-3 activation. Finally, we observed that LPA regulates the expression of genes related to the cell cycle and that the combined inhibition of ROCK and STAT-3 prevented cell cycle progression and increased the LPA-induced expression of cyclins E1, A2 and B1 to a greater degree than either inhibitor alone. Overall, these results demonstrate that LPA increases the proliferative potential of colon adenocarcinoma HCT-116 cells through a mechanism involving cooperation between the Rho-ROCK and STAT3 pathways involved in cell

  18. Lidocaine induces ROCK-dependent membrane blebbing and subsequent cell death in rabbit articular chondrocytes.

    Science.gov (United States)

    Maeda, Tsutomu; Toyoda, Futoshi; Imai, Shinji; Tanigawa, Hitoshi; Kumagai, Kousuke; Matsuura, Hiroshi; Matsusue, Yoshitaka

    2016-05-01

    Local anesthetics are administered intraarticularly for pain control in orthopedic clinics and surgeries. Although previous studies have shown that local anesthetics can be toxic to chondrocytes, the underlying cellular mechanisms remain unclear. The present study investigates acute cellular responses associated with lidocaine-induced toxicity to articular chondrocytes. Rabbit articular chondrocytes were exposed to lidocaine and their morphological changes were monitored with live cell microscopy. The viability of chondrocytes was evaluated using a fluorescence based LIVE/DEAD assay. Acute treatment of chondrocytes with lidocaine (3-30 mM) induced spherical protrusions on the cell surface (so called "membrane blebbing") in a time- and concentration-dependent manner. The concentration-response relationship for the lidocaine effect was shifted leftward by elevating extracellular pH, as expected for the non-ionized lidocaine being involved in the bleb formation. ROCK (Rho-kinase) inhibitors Y-27632 and fasudil completely prevented the lidocaine-induced membrane blebbing, suggesting that ROCK activation is required for bleb formation. Caspase-3 levels were unchanged by 10 mM lidocaine (p = 0.325) and a caspase inhibitor z-VAD-fmk did not affect the lidocaine-induced blebbing (p = 0.964). GTP-RhoA levels were significantly increased (p ROCK inhibitors or a myosin-II inhibitor blebbistatin (p ROCK-dependent membrane blebbing and thereby produces a cytotoxic effect on chondrocytes. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:754-762, 2016.

  19. Precarious rock and overturned transformer evidence for ground shaking in the Ms 7.7 Kern County earthquake: An analog for disastrous shaking from a major thrust fault in the Los Angeles basin

    Science.gov (United States)

    Brune, J.N.; Anooshehpoor, A.; Shi, B.; Zheng, Yen

    2004-01-01

    Precariously balanced rocks and overturned transformers in the vicinity of the White Wolf fault provide constraints on ground motion during the 1952 Ms 7.7 Kern County earthquake, a possible analog for an anticipated large earthquake in the Los Angeles basin (Shaw et al., 2002; Dolan et al., 2003). On the northeast part of the fault preliminary estimates of ground motion on the footwall give peak accelerations considerably lower than predicted by standard regression curves. On the other hand, on the hanging-wall, there is evidence of intense ground shattering and lack of precarious rocks, consistent with the intense hanging-wall accelerations suggested by foam-rubber modeling, numerical modeling, and observations from previous thrust fault earthquakes. There is clear evidence of the effects of rupture directivity in ground motions on the hanging-wall side of the fault (from both precarious rocks and numerical simulations). On the southwest part of the fault, which is covered by sediments, the thrust fault did not reach the surface ("blind" thrust). Overturned and damaged transformers indicate significant transfer of energy from the hanging wall to the footwall, an effect that may not be as effective when the rupture reaches the surface (is not "blind"). Transformers near the up-dip projection of the fault tip have been damaged or overturned on both the hanging-wall and footwall sides of the fault. The transfer of energy is confirmed in a numerical lattice model and could play an important role in a similar situation in Los Angeles. We suggest that the results of this study can provide important information for estimating the effects of a large thrust fault rupture in the Los Angeles basin, specially given the fact that there is so little instrumental data from large thrust fault earthquakes.

  20. Partial deletion of ROCK2 protects mice from high-fat diet-induced cardiac insulin resistance and contractile dysfunction.

    Science.gov (United States)

    Soliman, Hesham; Nyamandi, Vongai; Garcia-Patino, Marysol; Varela, Julia Nogueira; Bankar, Girish; Lin, Guorong; Jia, Zhengping; MacLeod, Kathleen M

    2015-07-01

    Obesity is associated with cardiac insulin resistance and contractile dysfunction, which contribute to the development of heart failure. The RhoA-Rho kinase (ROCK) pathway has been reported to modulate insulin resistance, but whether it is implicated in obesity-induced cardiac dysfunction is not known. To test this, wild-type (WT) and ROCK2(+/-) mice were fed normal chow or a high-fat diet (HFD) for 17 wk. Whole body insulin resistance, determined by an insulin tolerance test, was observed in HFD-WT, but not HFD-ROCK2(+/-), mice. The echocardiographically determined myocardial performance index, a measure of global systolic and diastolic function, was significantly increased in HFD-WT mice, indicating a deterioration of cardiac function. However, no change in myocardial performance index was found in hearts from HFD-ROCK2(+/-) mice. Speckle-tracking-based strain echocardiography also revealed regional impairment in left ventricular wall motion in hearts from HFD-WT, but not HFD-ROCK2(+/-), mice. Activity of ROCK1 and ROCK2 was significantly increased in hearts from HFD-WT mice, and GLUT4 expression was significantly reduced. Insulin-induced phosphorylation of insulin receptor substrate (IRS) Tyr(612), Akt, and AS160 was also impaired in these hearts, while Ser(307) phosphorylation of IRS was increased. In contrast, the increase in ROCK2, but not ROCK1, activity was prevented in hearts from HFD-ROCK2(+/-) mice, and cardiac levels of TNFα were reduced. This was associated with normalization of IRS phosphorylation, downstream insulin signaling, and GLUT4 expression. These data suggest that increased activation of ROCK2 contributes to obesity-induced cardiac dysfunction and insulin resistance and that inhibition of ROCK2 may constitute a novel approach to treat this condition.

  1. Evolution trends in vulnerability of R/C buildings exposed to earthquake induced landslide hazard

    Science.gov (United States)

    Fotopoulou, S.; Pitilakis, K.

    2012-04-01

    The assessment of landslide risk depends on the evaluation of landslide hazard and the vulnerability of exposed structures which both change with time. The real, dynamic vulnerability modeling of structures due to landslides may be significantly affected by aging considerations, anthropogenic actions, cumulative damage from past landslide events and retrofitting measures. The present work aims at the development of an efficient analytical methodology to assess the evolution of building vulnerability with time exposed to earthquake -induced landslide hazard. In particular, the aging of typical RC buildings is considered by including probabilistic models of corrosion deterioration of the RC elements within the vulnerability modeling framework. Two potential adverse corrosion scenarios are examined: chloride and carbonation induced corrosion of the steel reinforcement. An application of the proposed methodology to reference low-rise RC buildings exposed to the combined effect of seismically induced landslide differential displacements and reinforcement corrosion is provided. Both buildings with stiff and flexible foundation system standing near the crest of a potentially precarious soil slope are examined. Non linear static time history analyses of the buildings are performed using a fibre-based finite element code. In this analysis type, the applied loads (displacements) at the foundation level vary in the pseudo-time domain, according to a load pattern prescribed as the differential permanent landslide displacement (versus time) curves triggered by the earthquake. The distribution for the corrosion initiation time is assessed through Monte Carlo simulation using appropriate probabilistic models for the carbonation and the chloride induced corrosion. Then, the loss of area of steel over time due to corrosion of the RC elements is modeled as a reduction in longitudinal reinforcing bar cross-sectional area in the fibre section model. Time dependent structural limit

  2. Stratigraphic control on earthquake-induced liquefaction: A case study from the Central Po Plain (Italy)

    Science.gov (United States)

    Amorosi, A.; Bruno, L.; Facciorusso, J.; Piccin, A.; Sammartino, I.

    2016-11-01

    Studies on earthquake-induced liquefaction tied to high-resolution stratigraphic analysis have been rarely undertaken. We report the results of a multidisciplinary study from the Quistello-Moglia area, in the central Po Plain (northern Italy). In this region, combined stratigraphic, sedimentological, geotechnical, and geochemical data allowed assessment of liquefaction potential and identification of the primary source for liquefaction, following the second main shock (Mw 6) of the 2012 Po Plain earthquake. Using Cone Penetration Test (CPT)-based simplified procedures for liquefaction hazard evaluation, we assessed the highest liquefaction potential of Holocene, fluvial-channel and related (crevasse/levee) fine sand-silt facies encased in thick, mud-prone floodplain and swamp successions. The liquefaction potential, and the intensity of the manifestations induced on the ground surface, decreased for the vertically-amalgamated, sheet-like Pleistocene sandy fluvial units encountered at depths greater than 13 m. Floodplain and swamp deposits were virtually non-liquefiable. In the Quistello area, the compositional characterization of sands that were liquefied and extruded during the 2012 earthquake reveals the diagnostic geochemical fingerprint of sediment carried by the Po River, as opposed to the Apennine composition of surficial sediments. These data rule out proximity of liquefied layers to the surface, and attest the buried, meandering Po River system at depths of 7-10 m most likely representing the source for the liquefied sand that vented to the surface. Similarly, at Moglia, liquefied sands were likely sourced from loose and saturated, ribbon-shaped, fluvial sand bodies encased in mud, though at shallower (4-7 m) depths. Pronounced liquefaction phenomena in alluvial plain systems are commonly believed to be associated primarily with elongate topographic ridges following paleo-river courses. Here, we document that under favorable stratigraphic conditions

  3. 潜在地震滑坡危险区区划方法%Hazards zonation for potential earthquake-induced landslide area

    Institute of Scientific and Technical Information of China (English)

    陈晓利; 冉洪流; 王明明

    2012-01-01

    Earthquake-induced landslide is different from landslide triggered by rainstorms. Compared with landslides caused by rain, landslides induced by earthquake have more wide and dense space distribution and bigger scale, and can cause tremendous loss both to properties and lives. Earthquake-induced landslides usually cannot be prevented by current mitigation measures, thus, it becomes more and more important to develop a useful skill of assessing the hazard of landslides triggered by earthquake for land planning. This paper presents a method for zonation of potential earthquake-induced landslide area based on seismic hazard analysis. The approach takes account of uncertainty about earthquake location, intensity and recurrence, as well as space distribution of seismic peak ground acceleration. The study selects the damaged region in 2008. 5. 12 Wenchuan Earthquake as target area, and divided potential seismic source zone on the studying of geology, tectonics and seismic activity in this region. On the basis of potential seismic source zone division, this paper calculates the seismic peak ground acceleration according to different probability of exceedance of 10Mi, 5% and 2% in 50a using seismic hazard analysis method proposed by Cornell in 1968, and then assesses earthquake-induced landslide hazard of study region with comprehensive indexes model. In this model, the hazard is classified into 4 grades as high, secondary high, secondary low and low, and five indexes are used including seismic peak ground acceleration, slope angle, rock type, and distance to faults and rivers. The result of hazards zonation for potential earthquake-induced landslide in the study area shows that landslide areas in Wenchuan earthquake such as Wenchuan county, Beichuan county. Maoxian county et al, are located at areas of high or secondary high grades. In Leiguzhen area of Beichuan county, where high resolution DEM data is available, the zonation result shows good correlation with reality

  4. Functional relationship among PLK2, PLK4 and ROCK2 to induce centrosome amplification.

    Science.gov (United States)

    Ling, Hongbo; Hanashiro, Kazuhiko; Luong, Tran H; Benavides, Luis; Fukasawa, Kenji

    2015-01-01

    The presence of more than 2 centrosomes (centrosome amplification) leads to defective mitosis and chromosome segregation errors, is frequently found in a variety of cancer types, and believed to be the major cause of chromosome instability. One mechanism for generation of amplified centrosomes is over-duplication of centrosomes in a single cell cycle, which is expected to occur when cells are temporarily arrested. There are a growing number of kinases that are critical for induction and promotion of centrosome amplification in the cell cycle-arrested cells, including Rho-associated kinase (ROCK2), Polo-like kinase 2 (PLK2) and PLK4. Here, we tested whether these kinases induce centrosome amplification in a linear pathway or parallel pathways. We first confirmed that ROCK2, PLK2 and PLK4 are all essential for centrosomes to re-duplicate in the cells arrested by exposure to DNA synthesis inhibitor. Using the centrosome amplification rescue assay, we found that PLK2 indirectly activates ROCK2 via phosphorylating nucleophosmin (NPM), and PLK4 functions downstream of ROCK2 to drive centrosome amplification in the arrested cells.

  5. The November 2011 M5.7 Oklahoma Earthquake: Induced or Triggered?

    Science.gov (United States)

    Sumy, D. F.; Cochran, E. S.; Aminzadeh, F.

    2013-12-01

    On 6 November 2011, a M5.7 right-lateral strike-slip earthquake ruptured a section of the Wilzetta fault that strikes approximately N55E in Prague, Oklahoma. This earthquake was preceded by a right-lateral strike-slip M5.0 foreshock that occurred on 5 November 2011 and followed by a left-lateral strike-slip M5.0 aftershock that occurred on 8 November 2011. Seismicity during the sequence delineates three distinct near-vertical fault planes. The M5.0 foreshock was within several hundred meters of two active, high-volume injection wells, and thus was interpreted as potentially induced by Keranen et al. [2013]. Immediately following the M5.0 foreshock, three temporary seismometers were installed, with additional 44 stations installed after the M5.7 mainshock. These 47 stations recorded thousands of foreshocks and aftershocks that surrounded the three M≥5.0 events. We hypothesize that while the M5.0 foreshock (Event A) is potentially induced by anthropogenic activities, the static stress change imparted by this event triggered the M5.7 mainshock (Event B). To investigate this hypothesis, we calculate the static Coulomb stress change on 110 focal mechanism solutions examined in this study. Many of the focal mechanisms are consistent with the rupture planes defined by the seismicity of Events A and B. However, several of the focal mechanism solutions exhibit dip-slip focal mechanisms and/or are more consistent with the M5.0 aftershock (Event C). Event C occurs on a previously unmapped, east-west striking left-lateral fault plane, which differs substantially from the orientation of Events A and B. The diverse range of focal mechanism solutions suggests complex fault interactions within the Wilzetta fault system. Based on these focal mechanism solutions, we investigate the static stress changes imparted on the aftershocks that result from each of the M≥5.0 earthquakes. We find that the stress change induced by the Event A increases the stress at the hypocentral location

  6. Simulation of rock fragmentation induced by a tunnel boring machine disk cutter

    Directory of Open Access Journals (Sweden)

    Huiyun Li

    2016-05-01

    Full Text Available A constitutive model based on the Johnson–Cook material model and the extended Drucker–Prager strength criterion was implemented in LS-DYNA to simulate the rock failure process induced by a single disk cutter of a tunnel boring machine. The normal, rolling, and side forces were determined by numerical tests. The simulation results showed that the normal and rolling forces increased with increasing penetration while the side force changed little. The normal force also increased under the conditions of confining pressures. The damage region of rock and cutting forces were also obtained by simulation of two disk cutters acting in tandem with different cutting spacings. The optimum ratio of cutter spacing to penetration depth determined from numerical modeling agrees well with that obtained by linear cutting machine tests. The average normal and rolling forces acting on the first cutter are slightly greater than those acting on the second when the cutting disk spacing is relatively small. The numerical modeling was verified to accurately capture the fragmentation of rock induced by disk cutter.

  7. Thermoelastic stresses induced by non-isothermal fluid injection into fractured rock

    Science.gov (United States)

    Mossop, A.; Matthai, S. K.

    2003-04-01

    The injection of cold water into hot fractured rock occurs in a number of industrial scenarios, most commonly in the recharge of geothermal reservoirs and during waterflood operations in hydrocarbon reservoirs. The cold water cools the rock local to the fracture flow pathways, the cooled rock contracts, causing localised stress perturbations. Essentially analogous physical processes are involved in the injection of hot fluids into cooler rock such as occur in steam flood operations in viscous oil recovery. In this study we investigate such thermoelastic stresses induced by non-isothermal injection into a three dimensional fractured rock mass. The starting point of our analysis is an idealized model of injection into a single, uniform, horizontal fracture. For this case we have previously found semi-analytic solutions and analytic estimates of the stress perturbation and these are in turn used for cross-verification of an isoparametric, quadratic, finite element model of the system. In the numerical model the fractures are treated as discrete conductive channels within the matrix and an additional feature is that the matrix itself can be assigned a non-zero permeability. As the numerical simulator follows a fundamentally different methodology for solving these thermoelastic problems, the results help to validate some of the scaling relationships and non-intuitive behaviour deduced from the analytic estimates (e.g. for a broad range of flow rates, fracture normal stress perturbations decrease with increasing injection rates). The finite element model is then used to explore progressively more complex fracture geometries and networks. Finally we investigate the validity of a continuum limit as fracture densities increase to the point that fracture separation length scales are comparable with thermal diffusion length scales.

  8. Statistical discrimination of induced and tectonic earthquake sequences in Central and Eastern US based on waveform detected catalogs

    Science.gov (United States)

    Meng, X.; Daniels, C.; Smith, E.; Peng, Z.; Chen, X.; Wagner, L. S.; Fischer, K. M.; Hawman, R. B.

    2015-12-01

    Since 2001, the number of M>3 earthquakes increased significantly in Central and Eastern United States (CEUS), likely due to waste-water injection, also known as "induced earthquakes" [Ellsworth, 2013]. Because induced earthquakes are driven by short-term external forcing and hence may behave like earthquake swarms, which are not well characterized by branching point-process models, such as the Epidemic Type Aftershock Sequence (ETAS) model [Ogata, 1988]. In this study we focus on the 02/15/2014 M4.1 South Carolina and the 06/16/2014 M4.3 Oklahoma earthquakes, which likely represent intraplate tectonic and induced events, respectively. For the South Carolina event, only one M3.0 aftershock is identified by the ANSS catalog, which may be caused by a lack of low-magnitude events in this catalog. We apply a recently developed matched filter technique to detect earthquakes from 02/08/2014 to 02/22/2014 around the epicentral region. 15 seismic stations (both permanent and temporary USArray networks) within 100 km of the mainshock are used for detection. The mainshock and aftershock are used as templates for the initial detection. Newly detected events are employed as new templates, and the same detection procedure repeats until no new event can be added. Overall we have identified more than 10 events, including one foreshock occurred ~11 min before the M4.1 mainshock. However, the numbers of aftershocks are still much less than predicted with the modified Bath's law. For the Oklahoma event, we use 1270 events from the ANSS catalog and 182 events from a relocated catalog as templates to scan through continuous recordings 3 days before to 7 days after the mainshock. 12 seismic stations within the vicinity of the mainshock are included in the study. After obtaining more complete catalogs for both sequences, we plan to compare the statistical parameters (e.g., b, a, K, and p values) between the two sequences, as well as their spatial-temporal migration pattern, which may

  9. Application of optical remote sensing in the Wenchuan earthquake assessment

    Science.gov (United States)

    Zhang, Bing; Lei, Liping; Zhang, Li; Liu, Liangyun; Zhu, Boqin; Zuo, Zhengli

    2009-06-01

    A mega-earthquake of magnitude 8 of Richter scale occurred in Wenchuan County, Sichuan Province, China on May 12, 2008. The earthquake inflicted heavy loss of human lives and properties. The Wenchuan earthquake induced geological disasters, house collapse, and road blockage. In this paper, we demonstrate an application of optical remote sensing images acquired from airborne and satellite platforms in assessing the earthquake damages. The high-resolution airborne images were acquired by the Chinese Academy of Sciences (CAS). The pre- and post-earthquake satellite images of QuickBird, IKONOS, Landsat TM, ALOS, and SPOT were collected by the Center for Earth Observation & Digital Earth (CEODE), CAS, and some of the satellite data were provided by the United States, Japan, and the European Space Agency. The pre- and post-earthquake remote sensing images integrated with DEM and GIS data were adopted to monitor and analyze various earthquake disasters, such as road blockage, house collapse, landslides, avalanches, rock debris flows, and barrier lakes. The results showed that airborne optical images provide a convenient tool for quick and timely monitoring and assessing of the distribution and dynamic changes of the disasters over the earthquake-struck regions. In addition, our study showed that the optical remote sensing data integrated with GIS data can be used to assess disaster conditions such as damaged farmlands, soil erosion, etc, which in turn provides useful information for the postdisaster reconstruction.

  10. Induced Seismicity: What is the Size of the Largest Expected Earthquake?

    Science.gov (United States)

    Zoeller, G.; Holschneider, M.

    2014-12-01

    The injections of fluids is a well-known origin for the triggering of earthquake sequences. The growing number of projects related to enhanced geothermal systems, fracking and others has led to the question, which maximum earthquake magnitude can be expected as a consequence of fluid injection. This question is addressed from the perspective of statistical analysis. Using basic empirical laws of earthquake statistics, we estimate the magnitude MT of the maximum expected earthquake in a pre-defined future time window T. A case study of the fluid injection site at Paradox Valley, Colorado, USA, demonstrates that the magnitude m=4.3 of the largest observed earthquake on 27 May 2000 is lying very well within the expectation from past seismicity without adjusting any parameters. Vice versa, for a given maximum tolerable earthquake at an injection site, we can constrain the corresponding amount of injected fluids that must not be exceeded within pre-defined confidence bounds.

  11. Numerical simulation of earthquake effects on rock slope.%地震作用下边坡动力响应的数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    陈晓利; 李杨; 洪启宇; 赵永红

    2011-01-01

    汶川地震中在硬岩、次硬岩区域出现的一些大规模斜坡破坏现象超出了以往对地震作用下边坡稳定性问题的认识.本文使用FEPG有限元程序分析了水平和垂直2种不同加载方式作用下,经过不同的震动持续时间,不含裂隙岩质坡体内部的应力场和位移场的变化规律.得出的结论认为,在输入震动振幅为0.1m的加载作用下,岩质边坡内部的应力和位移均出现极值:在边坡的顶部及坡面上最大拉伸应力值大于100MPa,超过了花岗岩、灰岩等硬岩、次硬岩的抗拉强度,可能使岩体产生破裂发生崩塌、滑坡灾害.研究结果还表明,与水平方向振动加载相比,垂直方向振动加载产生的响应结果要大,边坡顶端一点的在垂直方向位移的峰值达到0.43m,远远超过了输入的震动振幅,垂直方向的震动是引起边坡的不稳定的主要因素.此外,震动持续时间越长,造成的变形和破坏就越大.%During S. 12 Wenchuan Earthquake, there were lots of huge landslides and collapses occurred in hard rock areas. This uncommon phenomenon is beyond our knowledge. This paper discussed the different patterns of stress and displacement distributions within a perfect slope when it is subject to horizontal and vertical vibrational loads with various loading time. The analyses were performed using FEPG software. It is found that, both the stress and the displacement appear to reach their peak values when the amplitude of vibration load is 0. Lm. The maximum tensile stress at the top of a slope is bigger than around lOOMPa which exceeds the anti-tensile limit of typical hard rocks such as granite, and so on. As a result, the hard rock mass breaks and landslide occurs. The study results also show that vertical vibrational loads would cause bigger stress and displacement peaks than horizontal vibrational loads. Under vertical vibrational load, maximum vertical displacement reached 0. 43m which is much bigger

  12. The RhoA/ROCK Pathway Ameliorates Adhesion and Inflammatory Infiltration Induced by AGEs in Glomerular Endothelial Cells.

    Science.gov (United States)

    Rao, Jialing; Ye, Zengchun; Tang, Hua; Wang, Cheng; Peng, Hui; Lai, Weiyan; Li, Yin; Huang, Wanbing; Lou, Tanqi

    2017-01-05

    A recent study demonstrated that advanced glycation end products (AGEs) play a role in monocyte infiltration in mesangial areas in diabetic nephropathy. The Ras homolog gene family, member A Rho kinase (RhoA/ROCK) pathway plays a role in regulating cell migration. We hypothesized that the RhoA/ROCK pathway affects adhesion and inflammation in endothelial cells induced by AGEs. Rat glomerular endothelial cells (rGECs) were cultured with AGEs (80 μg/ml) in vitro. The ROCK inhibitor Y27632 (10 nmol/l) and ROCK1-siRNA were used to inhibit ROCK. We investigated levels of the intercellular adhesion molecule 1 (ICAM-1) and monocyte chemoattractant protein1 (MCP-1) in rGECs. Db/db mice were used as a diabetes model and received Fasudil (10 mg/kg/d, n = 6) via intraperitoneal injection for 12 weeks. We found that AGEs increased the expression of ICAM-1 and MCP-1 in rGECs, and the RhoA/ROCK pathway inhibitor Y27632 depressed the release of adhesion molecules. Moreover, blocking the RhoA/ROCK pathway ameliorated macrophage transfer to the endothelium. Reduced expression of adhesion molecules and amelioration of inflammatory cell infiltration in the glomerulus were observed in db/db mice treated with Fasudil. The RhoA/ROCK pathway plays a role in adhesion molecule expression and inflammatory cell infiltration in glomerular endothelial cells induced by AGEs.

  13. From field geology to earthquake simulation: A new state-of-The-art tool to investigate rock friction during the seismic cycle (SHIVA)

    NARCIS (Netherlands)

    Di Toro, G.; Niemeijer, A.; Tripoli, A.; Nielsen, S.; Di Felice, F.; Scarlato, P.G.; Spada, G.; Romeo, G.; Di Stefano, G.; Smith, S.; Mariano, S.

    2009-01-01

    Despite considerable effort over the past several decades, the mechanics of earthquake rupture remains largely unknown. Moderate- to large-magnitude earthquakes nucleate at 7–15 km depth and most information is retrieved from seismology, but information related to the physico-chemical processes

  14. From field geology to earthquake simulation: A new state-of-The-art tool to investigate rock friction during the seismic cycle (SHIVA)

    NARCIS (Netherlands)

    di Toro, Giulio; Niemeijer, André; Tripoli, Antonino; Nielsen, Stefan; Di Felice, Fabio; Scarlato, Piergiorgio; Spada, Giuseppe; Allesandroni, Roberto; Romeo, Giovanni; di Stefano, Giuseppe; Smith, Steven; Spagnuolo, Elena; Mariano, Sofia

    2010-01-01

    Despite considerable effort over the past several decades, the mechanics of earthquake rupture remains largely unknown. Moderate- to large-magnitude earthquakes nucleate at 7–15 km depth and most information is retrieved from seismology, but information related to the physico-chemical processes

  15. From field geology to earthquake simulation: A new state-of-The-art tool to investigate rock friction during the seismic cycle (SHIVA)

    NARCIS (Netherlands)

    di Toro, Giulio; Niemeijer, André; Tripoli, Antonino; Nielsen, Stefan; Di Felice, Fabio; Scarlato, Piergiorgio; Spada, Giuseppe; Allesandroni, Roberto; Romeo, Giovanni; di Stefano, Giuseppe; Smith, Steven; Spagnuolo, Elena; Mariano, Sofia

    2010-01-01

    Despite considerable effort over the past several decades, the mechanics of earthquake rupture remains largely unknown. Moderate- to large-magnitude earthquakes nucleate at 7–15 km depth and most information is retrieved from seismology, but information related to the physico-chemical processes acti

  16. From field geology to earthquake simulation: A new state-of-The-art tool to investigate rock friction during the seismic cycle (SHIVA)

    NARCIS (Netherlands)

    Di Toro, G.; Niemeijer, A.; Tripoli, A.; Nielsen, S.; Di Felice, F.; Scarlato, P.G.; Spada, G.; Romeo, G.; Di Stefano, G.; Smith, S.; Mariano, S.

    2009-01-01

    Despite considerable effort over the past several decades, the mechanics of earthquake rupture remains largely unknown. Moderate- to large-magnitude earthquakes nucleate at 7–15 km depth and most information is retrieved from seismology, but information related to the physico-chemical processes acti

  17. Assessment of stone columns as a mitigation technique of liquefaction-induced effects during Italian earthquakes (May 2012).

    Science.gov (United States)

    Forcellini, Davide; Tarantino, Angelo Marcello

    2014-01-01

    Soil liquefaction has been observed worldwide during recent major earthquakes with induced effects responsible for much of the damage, disruption of function, and considerable replacement expenses for structures. The phenomenon has not been documented in recent time with such damage in Italian context before the recent Emilia-Romagna Earthquake (May 2012). The main lateral spreading and vertical deformations affected the stability of many buildings and impacted social life inducing valuable lessons on liquefaction risk assessment and remediation. This paper aims first of all to reproduce soil response to liquefaction-induced lateral effects and thus to evaluate stone column mitigation technique effectiveness by gradually increasing the extension of remediation, in order to achieve a satisfactory lower level of permanent deformations. The study is based on the use of a FE computational interface able to analyse the earthquake-induced three-dimensional pore pressure generation adopting one of the most credited nonlinear theories in order to assess realistically the displacements connected to lateral spreading.

  18. Assessment of Stone Columns as a Mitigation Technique of Liquefaction-Induced Effects during Italian Earthquakes (May 2012

    Directory of Open Access Journals (Sweden)

    Davide Forcellini

    2014-01-01

    Full Text Available Soil liquefaction has been observed worldwide during recent major earthquakes with induced effects responsible for much of the damage, disruption of function, and considerable replacement expenses for structures. The phenomenon has not been documented in recent time with such damage in Italian context before the recent Emilia-Romagna Earthquake (May 2012. The main lateral spreading and vertical deformations affected the stability of many buildings and impacted social life inducing valuable lessons on liquefaction risk assessment and remediation. This paper aims first of all to reproduce soil response to liquefaction-induced lateral effects and thus to evaluate stone column mitigation technique effectiveness by gradually increasing the extension of remediation, in order to achieve a satisfactory lower level of permanent deformations. The study is based on the use of a FE computational interface able to analyse the earthquake-induced three-dimensional pore pressure generation adopting one of the most credited nonlinear theories in order to assess realistically the displacements connected to lateral spreading.

  19. ROCK activity affects IL-1-induced signaling possibly through MKK4 and p38 MAPK in Caco-2 cells.

    Science.gov (United States)

    Banerjee, Sayantan; McGee, Dennis W

    2016-09-01

    Elevated levels of interleukin-1 (IL-1) accompany inflammatory bowel disease. IL-1-stimulated intestinal epithelial cells can secrete potent chemokines like CXCL8 to exacerbate inflammation. Previously, we found that inhibiting the Rho-associated kinase (ROCK) could inhibit IL-1- or TNF-α-induced CXCL8 secretion by the Caco-2 colonic epithelial cell line. This ROCK inhibition did not affect IκBα phosphorylation and degradation, but suppressed the phosphorylation of c-Jun N-terminal kinase (JNK). Therefore, ROCK must play an important role in epithelial cell CXCL8 responses through an effect on the JNK signaling pathway. Here, we extend these studies by showing that inhibiting ROCK suppressed the IL-1-induced phosphorylation of MKK4, a known activator of JNK, but not MKK7. Yet, ROCK inhibition had no significant effect on the IL-1-induced phosphorylation of extracellular-signal-regulated kinase (ERK) 1/2. Inhibiting ROCK also suppressed the phosphorylation of p38 MAPK after IL-1 stimulation, but this inhibition had no significant effect on the stability of CXCL8 messenger RNA (mRNA) after IL-1 stimulation. These results suggest that ROCK may be important in IL-1-induced signaling through MKK4 to JNK and the activation of p38 MAPK. Finally, inhibiting ROCK in IL-1 and TNF-α co-stimulated Caco-2 cells also resulted in a significant suppression of CXCL8 secretion and mRNA levels suggesting that inhibiting ROCK may be a mechanism to inhibit the overall response of epithelial cells to both cytokines. These studies indicate a novel signaling event, which could provide a target for suppressing intestinal epithelial cells (IEC) chemokine responses involved in mucosal inflammation.

  20. RhoA and ROCK mediate histamine-induced vascular leakage and anaphylactic shock.

    Science.gov (United States)

    Mikelis, Constantinos M; Simaan, May; Ando, Koji; Fukuhara, Shigetomo; Sakurai, Atsuko; Amornphimoltham, Panomwat; Masedunskas, Andrius; Weigert, Roberto; Chavakis, Triantafyllos; Adams, Ralf H; Offermanns, Stefan; Mochizuki, Naoki; Zheng, Yi; Gutkind, J Silvio

    2015-04-10

    Histamine-induced vascular leakage is an integral component of many highly prevalent human diseases, including allergies, asthma and anaphylaxis. Yet, how histamine induces the disruption of the endothelial barrier is not well defined. By using genetically modified animal models, pharmacologic inhibitors and a synthetic biology approach, here we show that the small GTPase RhoA mediates histamine-induced vascular leakage. Histamine causes the rapid formation of focal adherens junctions, disrupting the endothelial barrier by acting on H1R Gαq-coupled receptors, which is blunted in endothelial Gαq/11 KO mice. Interfering with RhoA and ROCK function abolishes endothelial permeability, while phospholipase Cβ plays a limited role. Moreover, endothelial-specific RhoA gene deletion prevents vascular leakage and passive cutaneous anaphylaxis in vivo, and ROCK inhibitors protect from lethal systemic anaphylaxis. This study supports a key role for the RhoA signalling circuitry in vascular permeability, thereby identifying novel pharmacological targets for many human diseases characterized by aberrant vascular leakage.

  1. Geomorphic and geologic controls of geohazards induced by Nepal's 2015 Gorkha earthquake

    NARCIS (Netherlands)

    Kargel, J. S.; Leonard, G. J.; Shugar, D. H.; Haritashya, U. K.; Bevington, A.; Fielding, E. J.; Fujita, K.; Geertsema, M.; Miles, E. S.; Steiner, J.; Anderson, E.; Bajracharya, S.; Bawden, G. W.; Breashears, D. F.; Byers, A.; Collins, B.; Dhital, M. R.; Donnellan, A.; Evans, T. L.; Geai, M. L.; Glasscoe, M. T.; Green, D.; Gurung, D. R.; Heijenk, R.; Hilborn, A.; Hudnut, K.; Huyck, C.; Immerzeel, W. W.; Liming, Jiang; Jibson, R.; Kääb, A.; Khanal, N. R.; Kirschbaum, D.; Kraaijenbrink, P. D A; Lamsal, D.; Shiyin, Liu; Mingyang, Lv; McKinney, D.; Nahirnick, N. K.; Zhuotong, Nan; Ojha, S.; Olsenholler, J.; Painter, T. H.; Pleasants, M.; Pratima, K. C.; Yuan, Q. I.; Raup, B. H.; Regmi, D.; Rounce, D. R.; Sakai, A.; Donghui, Shangguan; Shea, J. M.; Shrestha, A. B.; Shukla, A.; Stumm, D.; van der Kooij, M.; Voss, K.; Xin, Wang; Weihs, B.; Wolfe, D.; Lizong, Wu; Xiaojun, Yao; Yoder, M. R.; Young, N.

    2016-01-01

    The Gorkha earthquake (magnitude 7.8) on 25 April 2015 and later aftershocks struck South Asia, killing ~9000 people and damaging a large region. Supported by a large campaign of responsive satellite data acquisitions over the earthquake disaster zone, our team undertook a satellite image survey of

  2. Geomorphic and geologic controls of geohazards induced by Nepal's 2015 Gorkha earthquake

    NARCIS (Netherlands)

    Kargel, J. S.; Leonard, G. J.; Shugar, D. H.; Haritashya, U. K.; Bevington, A.; Fielding, E. J.; Fujita, K.; Geertsema, M.; Miles, E. S.; Steiner, J.; Anderson, E.; Bajracharya, S.; Bawden, G. W.; Breashears, D. F.; Byers, A.; Collins, B.; Dhital, M. R.; Donnellan, A.; Evans, T. L.; Geai, M. L.; Glasscoe, M. T.; Green, D.; Gurung, D. R.; Heijenk, R.; Hilborn, A.; Hudnut, K.; Huyck, C.; Immerzeel, W. W.|info:eu-repo/dai/nl/290472113; Liming, Jiang; Jibson, R.; Kääb, A.; Khanal, N. R.; Kirschbaum, D.; Kraaijenbrink, P. D A; Lamsal, D.; Shiyin, Liu; Mingyang, Lv; McKinney, D.; Nahirnick, N. K.; Zhuotong, Nan; Ojha, S.; Olsenholler, J.; Painter, T. H.; Pleasants, M.; Pratima, K. C.; Yuan, Q. I.; Raup, B. H.; Regmi, D.; Rounce, D. R.; Sakai, A.; Donghui, Shangguan; Shea, J. M.; Shrestha, A. B.; Shukla, A.; Stumm, D.; van der Kooij, M.; Voss, K.; Xin, Wang; Weihs, B.; Wolfe, D.; Lizong, Wu; Xiaojun, Yao; Yoder, M. R.; Young, N.

    2016-01-01

    The Gorkha earthquake (magnitude 7.8) on 25 April 2015 and later aftershocks struck South Asia, killing ~9000 people and damaging a large region. Supported by a large campaign of responsive satellite data acquisitions over the earthquake disaster zone, our team undertook a satellite image survey of

  3. Curcumin inhibits LPA-induced invasion by attenuating RhoA/ROCK/MMPs pathway in MCF7 breast cancer cells.

    Science.gov (United States)

    Sun, Kai; Duan, Xiaoyi; Cai, Hui; Liu, Xiaohong; Yang, Ya; Li, Min; Zhang, Xiaoyun; Wang, Jiansheng

    2016-02-01

    Breast cancer generally shows poor prognosis because of its invasion and metastasis. Lysophosphatidic acid (LPA) induces and aggravates cancer invasion and metastasis by activating its downstream signal pathways. RhoA/ROCK/MMP signaling was found one of the LPA-induced pathways, which may be involved in invasion of breast cancer. Furthermore, we investigated whether this pathway was involved in curcumin's effect against LPA-induced invasion. LPA incubation was used to enhance invasion of MCF-7 breast cancer cells. RhoA expression was knocked-down by siRNA technique. MTT assay was used to evaluate the proliferation. Transwell assay was utilized to investigate the invasion ability of MCF-7 cells. Real-time PCR and Western blotting were used to assess the expressions of RhoA, ROCK1, ROCK2, MMP2 and MMP9 at both translational and transcriptional levels. The RhoA and ROCK activities were also evaluated. LPA incubation significantly boosted invasion rate of MCF-7. RhoA silencing by siRNA dramatically inhibited LPA-enhanced invasion. Concurrently, RhoA and ROCK activities and expression levels of RhoA, ROCK1, ROCK2, MMP2 and MMP9 were down-regulated by RhoA siRNA transfection. In order to avoid influence of cytotoxicity of curcumin, concentrations below 45 μmol/L were selected to further investigate the mechanism of curcumin's anti-invasion effect. Invasion of LPA-incubated MCF-7 cells was impaired by curcumin in a concentration-dependent manner. Concurrently, RhoA and ROCK activities and expression levels of RhoA, ROCK1, ROCK2, MMP2 and MMP9 were down-regulated by curcumin in a concentration-dependent manner. In conclusion, RhoA/ROCK/MMPs pathway activation is involved in LPA-induced invasion in MCF-7 cells; curcumin inhibited LPA-induced invasion in MCF-7 cells by attenuating RhoA/ROCK/MMPs pathway.

  4. Rho Kinase ROCK2 Mediates Acid-Induced NADPH Oxidase NOX5-S Expression in Human Esophageal Adenocarcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Jie Hong

    Full Text Available Mechanisms of the progression from Barrett's esophagus (BE to esophageal adenocarcinoma (EA are not fully understood. We have shown that NOX5-S may be involved in this progression. However, how acid upregulates NOX5-S is not well known. We found that acid-induced increase in NOX5-S expression was significantly decreased by the Rho kinase (ROCK inhibitor Y27632 in BE mucosal biopsies and FLO-1 EA cells. In addition, acid treatment significantly increased the Rho kinase activity in FLO-1 cells. The acid-induced increase in NOX5-S expression and H2O2 production was significantly decreased by knockdown of Rho kinase ROCK2, but not by knockdown of ROCK1. Conversely, the overexpression of the constitutively active ROCK2, but not the constitutively active ROCK1, significantly enhanced the NOX5-S expression and H2O2 production. Moreover, the acid-induced increase in Rho kinase activity and in NOX5-S mRNA expression was blocked by the removal of calcium in both FLO-1 and OE33 cells. The calcium ionophore A23187 significantly increased the Rho kinase activity and NOX5-S mRNA expression. We conclude that acid-induced increase in NOX5-S expression and H2O2 production may depend on the activation of ROCK2, but not ROCK1, in EA cells. The acid-induced activation of Rho kinase may be mediated by the intracellular calcium increase. It is possible that persistent acid reflux present in BE patients may increase the intracellular calcium, activate ROCK2 and thereby upregulate NOX5-S. High levels of reactive oxygen species derived from NOX5-S may cause DNA damage and thereby contribute to the progression from BE to EA.

  5. Rho Kinase ROCK2 Mediates Acid-Induced NADPH Oxidase NOX5-S Expression in Human Esophageal Adenocarcinoma Cells.

    Science.gov (United States)

    Hong, Jie; Li, Dan; Cao, Weibiao

    2016-01-01

    Mechanisms of the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. We have shown that NOX5-S may be involved in this progression. However, how acid upregulates NOX5-S is not well known. We found that acid-induced increase in NOX5-S expression was significantly decreased by the Rho kinase (ROCK) inhibitor Y27632 in BE mucosal biopsies and FLO-1 EA cells. In addition, acid treatment significantly increased the Rho kinase activity in FLO-1 cells. The acid-induced increase in NOX5-S expression and H2O2 production was significantly decreased by knockdown of Rho kinase ROCK2, but not by knockdown of ROCK1. Conversely, the overexpression of the constitutively active ROCK2, but not the constitutively active ROCK1, significantly enhanced the NOX5-S expression and H2O2 production. Moreover, the acid-induced increase in Rho kinase activity and in NOX5-S mRNA expression was blocked by the removal of calcium in both FLO-1 and OE33 cells. The calcium ionophore A23187 significantly increased the Rho kinase activity and NOX5-S mRNA expression. We conclude that acid-induced increase in NOX5-S expression and H2O2 production may depend on the activation of ROCK2, but not ROCK1, in EA cells. The acid-induced activation of Rho kinase may be mediated by the intracellular calcium increase. It is possible that persistent acid reflux present in BE patients may increase the intracellular calcium, activate ROCK2 and thereby upregulate NOX5-S. High levels of reactive oxygen species derived from NOX5-S may cause DNA damage and thereby contribute to the progression from BE to EA.

  6. Liquefaction-fluidization induced land subsidence: impact of the 2011 Tohoku earthquake on reclaimed land around Tokyo bay area, Japan

    OpenAIRE

    A. Kagawa; Furuno, K; Kusuda, T.; Sakai, Y.; Yoshida, T.; Kazaoka, O.

    2015-01-01

    The 2011 Tohoku earthquake caused major liquefaction-induced, ground deformation of the reclaimed land surrounding Tokyo Bay. In this area, liquefaction was visibly manifest by sand boils, ejection of sandy water, land subsidence and floating underground tanks. The level measurements show a correspondence between the degree of liquefaction-fluidization and the amount of subsidence. The strata most susceptible to liquefaction are hydraulically emplaced dredged fill and artifi...

  7. Observations of changes in waveform character induced by the 1999 M w7.6 Chi-Chi earthquake

    Science.gov (United States)

    Chen, K.H.; Furumura, T.; Rubinstein, J.; Rau, R.-J.

    2011-01-01

    We observe changes in the waveforms of repeating earthquakes in eastern Taiwan following the 1999 Mw7.6 Chi-Chi earthquake, while their recurrence intervals appear to be unaffected. There is a clear reduction in waveform similarity and velocity changes indicated by delayed phases at the time of the Chi-Chi event. These changes are limited to stations in and paths that cross the 70 ?? 100 km region surrounding the Chi-Chi source area, the area where seismic intensity and co-seismic surface displacements were largest. This suggests that damage at the near-surface is responsible for the observed waveform changes. Delays are largest in the late S-wave coda, reaching approximately 120 ms. This corresponds to a path averaged S wave velocity reduction of approximately 1%. There is also evidence that damage in the fault-zone caused changes in waveform character at sites in the footwall, where source-receiver paths propagate either along or across the rupture. The reduction in waveform similarity persists through the most recent repeating event in our study (November 15, 2007), indicating that the subsurface damage induced by the Chi-Chi earthquake did not fully heal within the first 8 years following the Chi-Chi earthquake. ?? 2011 by the American Geophysical Union.

  8. Earthquake-induced crustal deformation and consequences for fault displacement hazard analysis of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Gürpinar, Aybars, E-mail: aybarsgurpinar2007@yahoo.com [Nuclear & Risk Consultancy, Anisgasse 4, 1221 Vienna (Austria); Serva, Leonello, E-mail: lserva@alice.it [Independent Consultant, Via dei Dauni 1, 00185 Rome (Italy); Livio, Franz, E-mail: franz.livio@uninsubria.it [Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell’Insubria, Via Velleggio, 11, 22100 Como (Italy); Rizzo, Paul C., E-mail: paul.rizzo@rizzoasoc.com [RIZZO Associates, 500 Penn Center Blvd., Suite 100, Pittsburgh, PA 15235 (United States)

    2017-01-15

    Highlights: • A three-step procedure to incorporate coseismic deformation into PFDHA. • Increased scrutiny for faults in the area permanently deformed by future strong earthquakes. • These faults share with the primary structure the same time window for fault capability. • VGM variation may occur due to tectonism that has caused co-seismic deformation. - Abstract: Readily available interferometric data (InSAR) of the coseismic deformation field caused by recent seismic events clearly show that major earthquakes produce crustal deformation over wide areas, possibly resulting in significant stress loading/unloading of the crust. Such stress must be considered in the evaluation of seismic hazards of nuclear power plants (NPP) and, in particular, for the potential of surface slip (i.e., probabilistic fault displacement hazard analysis - PFDHA) on both primary and distributed faults. In this study, based on the assumption that slip on pre-existing structures can represent the elastic response of compliant fault zones to the permanent co-seismic stress changes induced by other major seismogenic structures, we propose a three-step procedure to address fault displacement issues and consider possible influence of surface faulting/deformation on vibratory ground motion (VGM). This approach includes: (a) data on the presence and characteristics of capable faults, (b) data on recognized and/or modeled co-seismic deformation fields and, where possible, (c) static stress transfer between source and receiving faults of unknown capability. The initial step involves the recognition of the major seismogenic structures nearest to the site and their characterization in terms of maximum expected earthquake and the time frame to be considered for determining their “capability” (as defined in the International Atomic Energy Agency - IAEA Specific Safety Guide SSG-9). Then a GIS-based buffer approach is applied to identify all the faults near the NPP, possibly influenced by

  9. Pyrometamorphism of Fault Zone Rocks Induced by Frictional Heating in High-velocity Friction Tests: Reliable Records of Seismic Slip?

    Science.gov (United States)

    Ree, J.; Ando, J.; Kim, J.; Han, R.; Shimamoto, T.

    2008-12-01

    Recognition of seismic slip zone is important for a better understanding of earthquake generation processes in fault zones and paleoseismology. However, there has been no reliable record of ancient seismic slip except pseudotachylyte. Recently, it has been suggested that decomposition (dehydration or decarbonation) products due to frictional heating can be used as a seismic slip record. The decomposition products, however, can be easily rehydrated or recarbonated with pervasive fluid migration in the fault zone after seismic slip, raising some question about their stability as a seismic slip record. Here, we review microstructural and mineralogical changes of the simulated fault zones induced by frictional heating (pyrometamorphism) from high-velocity friction tests (HVFT) on siltstone, sandstone and carbonates at seismic slip rates, and discuss on their stability after seismic slip. HVFT on siltstone generates pseuodotachylyte in the principal slip zone (0.30-0.75 mm thick) with 'damage' layer (0.1-0.2 mm thick) along its margins. Chlorite in the damage layer suffers an incipient dehydration with many voids (0.2-1.0 μm in diameter) in transmission electron microscopy (TEM), appearing as dark tiny spots both in plane-polarized light and back-scattered electron (BSE) photomicrographs. HVFT on brown sandstone induces a color change of wall rocks adjacent to the principal slip zone (brown to red) due to the dehydration of iron hydroxides with frictional heating. These dehydration products in siltstone and sandstone due to frictional heating may be unstable since they would be easily rehydrated with fluid infiltration after a seismic slip. HVFT on carbonates including Carrara marble and siderite-bearing gouges produces decarbonation products of nano-scale lime (CaO) and magnetite (Fe3O4), respectively. Lime is a very unstable phase whereas magnetite is a stable and thus may be used as an indicator of seismic slip. The simulated fault zones of Carrara marble contain

  10. Rock stress orientation measurements using induced thermal spalling in slim boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Hakami, Eva [Geosigma AB, Uppsala (Sweden)

    2011-05-15

    In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

  11. Do moderate magnitude earthquake generate seismically induced ground effects? The case study of the M w = 5.16, 29th December 2013 Matese earthquake (southern Apennines, Italy)

    Science.gov (United States)

    Valente, Ettore; Ascione, A.; Ciotoli, G.; Cozzolino, M.; Porfido, S.; Sciarra, A.

    2017-06-01

    Seismically induced ground effects characterize moderate to high magnitude seismic events, whereas they are not so common during seismic sequences of low to moderate magnitude. A low to moderate magnitude seismic sequence with a M w = 5.16 ± 0.07 main event occurred from December 2013 to February 2014 in the Matese ridge area, in the southern Apennines mountain chain. In the epicentral area of the M w = 5.16 main event, which happened on December 29th 2013 in the southeastern part of the Matese ridge, field surveys combined with information from local people and reports allowed the recognition of several earthquake-induced ground effects. Such ground effects include landslides, hydrological variations in local springs, gas flux, and a flame that was observed around the main shock epicentre. A coseismic rupture was identified in the SW fault scarp of a small-sized intermontane basin (Mt. Airola basin). To detect the nature of the coseismic rupture, detail scale geological and geomorphological investigations, combined with geoelectrical and soil gas prospections, were carried out. Such a multidisciplinary study, besides allowing reconstruction of the surface and subsurface architecture of the Mt. Airola basin, and suggesting the occurrence of an active fault at the SW boundary of such basin, points to the gravitational nature of the coseismic ground rupture. Based on typology and spatial distribution of the ground effects, an intensity I = VII-VIII is estimated for the M w = 5.16 earthquake according to the ESI-07 scale, which affected an area of at least 90 km2.

  12. Seismic response of rock joints and jointed rock mass

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, A.; Hsiung, S.M.; Chowdhury, A.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1996-06-01

    Long-term stability of emplacement drifts and potential near-field fluid flow resulting from coupled effects are among the concerns for safe disposal of high-level nuclear waste (HLW). A number of factors can induce drift instability or change the near-field flow patterns. Repetitive seismic loads from earthquakes and thermal loads generated by the decay of emplaced waste are two significant factors. One of two key technical uncertainties (KTU) that can potentially pose a high risk of noncompliance with the performance objectives of 10 CFR Part 60 is the prediction of thermal-mechanical (including repetitive seismic load) effects on stability of emplacement drifts and the engineered barrier system. The second KTU of concern is the prediction of thermal-mechanical-hydrological (including repetitive seismic load) effects on the host rock surrounding the engineered barrier system. The Rock Mechanics research project being conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA) is intended to address certain specific technical issues associated with these two KTUs. This research project has two major components: (i) seismic response of rock joints and a jointed rock mass and (ii) coupled thermal-mechanical-hydrological (TMH) response of a jointed rock mass surrounding the engineered barrier system (EBS). This final report summarizes the research activities concerned with the repetitive seismic load aspect of both these KTUs.

  13. On a model simulating lack of hydraulic connection between a man-made reservoir and the volume of poroelastic rock hosting the focus of a post-impoundment earthquake

    Science.gov (United States)

    Chander, Ramesh; Tomar, S. K.

    2016-12-01

    The idea that a direct hydraulic connection between a man-made reservoir and the foci of post-impoundment earthquakes may not exist at all sites is eminently credible on geological grounds. Our aim is to provide a simple earth model and related theory for use during investigations of earthquakes near new man-made reservoirs. We consider a uniform circular reservoir which rests on the top surface of a no-hydraulic-connection earth model (NHCEM). The model comprises a top elastic (E) layer, an intermediate poroelastic (P) layer, and a bottom elastic half space. The focus of a potential earthquake in the P layer is located directly under the reservoir. The E layer disrupts the hydraulic connection between the reservoir and the focus. Depth of water in the reservoir varies as H ' + hcos( ω t). Expressions for reservoir-induced stresses and pore pressure in different layers of the NHCEM are obtained by solving the boundary-value problem invoking full coupling between mean normal stress and pore pressure in the P layer. As an application of the derived mathematical results, we have examined and found that earthquakes on 60∘ normal faults may occur in the P-layer of a selected NHCEM at epochs of low reservoir level if the reservoir lies mostly in the footwall of the fault. The exercise was motivated by observations of such earthquakes under the man-made Lake Mead after it was impounded.

  14. On a model simulating lack of hydraulic connection between a man-made reservoir and the volume of poroelastic rock hosting the focus of a post-impoundment earthquake

    Indian Academy of Sciences (India)

    Ramesh Chander; S K Tomar

    2016-12-01

    The idea that a direct hydraulic connection between a man-made reservoir and the foci of postimpoundment earthquakes may not exist at all sites is eminently credible on geological grounds. Our aim is to provide a simple earth model and related theory for use during investigations of earthquakes near new man-made reservoirs. We consider a uniform circular reservoir which rests on the top surface of a no-hydraulic-connection earth model (NHCEM). The model comprises a top elastic (E) layer, an intermediate poroelastic (P) layer, and a bottom elastic half space. The focus of a potential earthquake in the P layer is located directly under the reservoir. The E layer disrupts the hydraulic connection between the reservoir and the focus. Depth of water in the reservoir varies as H'+h cos(ωt). Expressions for reservoir-induced stresses and pore pressure in different layers of the NHCEM are obtained by solving the boundary-value problem invoking full coupling between mean normal stress and pore pressure in the P layer. As an application of the derived mathematical results, we have examined and found that earthquakes on 60° normal faults may occur in the P-layer of a selected NHCEM at epochs of low reservoir level if the reservoir lies mostly in the footwall of the fault. The exercise was motivated by observations of such earthquakes under the man-made Lake Mead after it was impounded

  15. Aerial inventory of surficial geological effects induced by the recent Emilia earthquake (Italy: preliminary report

    Directory of Open Access Journals (Sweden)

    Giovanni Bertolini

    2012-10-01

    Full Text Available As a consequence of the two main shocks that recently struck the central alluvial Po Plain (May 20, 2012, Ml 5.9, and May 29, 2012, Ml 5.8, a great number of surficial geologic disturbances appeared over a wide area (ca. 500 km2, which extended up to 20 km from the epicenters. The affected area includes Mirabello, San Carlo, Sant'Agostino (Province of Ferrara, San Felice, Cavezzo, Concordia (Modena, Moglia and Quistello (Mantova. Most of the surficial effects that were observed during this study were clearly induced (directly or indirectly by sand liquefaction phenomena, such as sand volcanoes, burst of water and sand from domestic wells, tension cracks, lateral spreading and associated deformation, graben-like fracturing, and sink-holes. Other effects can probably be ascribed simply to the shaking of the ground (e.g., small collapses of irrigation canal walls. Lastly, there were also some features of dubious origin, such as two 'yellow crop spots' that are cited here with reservations. All of these data were surveyed by means of a small airplane that was especially adapted for this purpose. The aim of this study was to furnish a wide-ranging image of the surface deformation over the whole area impacted by these recent earthquakes, as an instrument towards more exhaustive research, both at the scientific and technical levels (e.g., seismic microzonation. […

  16. Spatial Distribution of Ground water Level Changes Induced by the 2006 Hengchun Earthquake Doublet

    Directory of Open Access Journals (Sweden)

    Yeeping Chia

    2009-01-01

    Full Text Available Water-level changes were ob served in 107 wells at 67 monitoring stations in the southern coastal plain of Tai wan during the 2006 Mw 7.1 Hengchun earthquake doublet. Two consecutive coseismic changes induced by the earth quake doublet can be observed from high-frequency data. Obervations from multiple-well stations indicate that the magnitude and direction of coseismic change may vary in wells of different depths. Coseismic rises were dominant on the south east side of the costal plain; whereas, coseismic falls prevailed on the north west side. In the transition zone, rises appeared in shallow wells whilst falls were evident in deep wells. As coseismic ground water level changes can reflect the tectonic strain field, tectonic extension likely dominates the deep subsurface in the transition area, and possibly in the en tire southern coastal plain. The coseismic rises in water level showed a tendency to de crease with distance from the hypocenter, but no clear trend was found for the coseismic falls.

  17. Earthquake-induced landslide-susceptibility mapping using an artificial neural network

    Science.gov (United States)

    Lee, S.; Evangelista, D. G.

    2006-07-01

    The purpose of this study was to apply and verify landslide-susceptibility analysis techniques using an artificial neural network and a Geographic Information System (GIS) applied to Baguio City, Philippines. The 16 July 1990 earthquake-induced landslides were studied. Landslide locations were identified from interpretation of aerial photographs and field survey, and a spatial database was constructed from topographic maps, geology, land cover and terrain mapping units. Factors that influence landslide occurrence, such as slope, aspect, curvature and distance from drainage were calculated from the topographic database. Lithology and distance from faults were derived from the geology database. Land cover was identified from the topographic database. Terrain map units were interpreted from aerial photographs. These factors were used with an artificial neural network to analyze landslide susceptibility. Each factor weight was determined by a back-propagation exercise. Landslide-susceptibility indices were calculated using the back-propagation weights, and susceptibility maps were constructed from GIS data. The susceptibility map was compared with known landslide locations and verified. The demonstrated prediction accuracy was 93.20%.

  18. Earthquake-induced landslide-susceptibility mapping using an artificial neural network

    Directory of Open Access Journals (Sweden)

    S. Lee

    2006-01-01

    Full Text Available The purpose of this study was to apply and verify landslide-susceptibility analysis techniques using an artificial neural network and a Geographic Information System (GIS applied to Baguio City, Philippines. The 16 July 1990 earthquake-induced landslides were studied. Landslide locations were identified from interpretation of aerial photographs and field survey, and a spatial database was constructed from topographic maps, geology, land cover and terrain mapping units. Factors that influence landslide occurrence, such as slope, aspect, curvature and distance from drainage were calculated from the topographic database. Lithology and distance from faults were derived from the geology database. Land cover was identified from the topographic database. Terrain map units were interpreted from aerial photographs. These factors were used with an artificial neural network to analyze landslide susceptibility. Each factor weight was determined by a back-propagation exercise. Landslide-susceptibility indices were calculated using the back-propagation weights, and susceptibility maps were constructed from GIS data. The susceptibility map was compared with known landslide locations and verified. The demonstrated prediction accuracy was 93.20%.

  19. Liquefaction Susceptibility of Soils With Clay Particles from Earthquake-induced Landslides

    Institute of Scientific and Technical Information of China (English)

    CHEN Chuan-sheng; JIANG Xin; ZHANG Xu

    2007-01-01

    The main reason for earthquake-induced landslides is liquefaction of soil, a process considered to occur mostly in sandy soils. Liquefaction can occur in clayey soils has also been reported and proven in the recent literature, but liquefaction in clayey soils still remains unclear and there are many questions that need to be addressed. In order to address these questions, an depth study on the liquefaction potential of clayey soils was conducted on the basis of field investigation and a series of laboratory tests on the samples collected from the sliding surface of the landslides. The liquefaction potential of the soils was studied by means of undrained cyclic ring-shear tests. Research results show that the liquefaction potential of sandy soils is higher than that of clayey soils given the same void ratio;the soil resistance to liquefaction rises with an increase in plasticity for clayey soils; relation between plasticity index and the liquefaction potential of soil can be used in practical application to estimate the liquefaction potential of soil.

  20. Gas and Dust Phenomena of Mega-earthquakes and the Cause

    Science.gov (United States)

    Yue, Z.

    2013-12-01

    dense natural (methane) gas suddenly escaped from deep crust traps along deep fault zones. References Yue, ZQ, 2009. The source of energy power directly causing the May 12 Wenchuan Earthquake: Huge extremely pressurized natural gases trapped in deep Longmen Shan faults. News Journal of China Society of Rock Mechanics and Engineering, 86 (2009 (2)), 45-50. Yue, ZQ, 2010. Features and mechanism of coseismic surface ruptures by Wenchuan Earthquake. in Rock Stress and Earthquake, edited by Furen Xie, Taylor & Francis Group, London, ISBN 978-0-415-60165-8, 761-768. Yue, ZQ, 2013a. Natural gas eruption mechanism for earthquake landslides: illustrated with comparison between Donghekou and Papandayan Rockslide-debris flows. in Earthquake-induced Landslides, K. Ugai et al. (eds.), Springer-Verlage Berlin, Chapter 51: pp. 485-494 Yue ZQ, 2013b. On incorrectness in elastic rebound theory for cause of earthquakes. Paper No. S20-003 of Session S20, Proceedings of the 13th International Conference on Fracture, June 16-21, Beijing. Yue ZQ, 2013c. On nature of earthquakes with cause of compressed methane gas expansion and migration in crustal rocks, in Proceedings of Fifth Biot Conference on Poromechanics in Memory of Karl von Terzaghi (1883-1963), July 10-12, Vienna, edited by C. Hellmich et al, @ASCE, pp. 507-516.

  1. Liquefaction-induced lateral spreading in Oceano, California, during the 2003 San Simeon Earthquake

    Science.gov (United States)

    Holzer, Thomas L.; Noce, Thomas E.; Bennett, Michael J.; Di Alessandro, Carola; Boatwright, John; Tinsley, John C.; Sell, Russell W.; Rosenberg, Lewis I.

    2004-01-01

    The December 22, 2003, San Simeon, California, (M6.5) earthquake caused damage to houses, road surfaces, and underground utilities in Oceano, California. The community of Oceano is approximately 50 miles (80 km) from the earthquake epicenter. Damage at this distance from a M6.5 earthquake is unusual. To understand the causes of this damage, the U.S. Geological Survey conducted extensive subsurface exploration and monitoring of aftershocks in the months after the earthquake. The investigation included 37 seismic cone penetration tests, 5 soil borings, and aftershock monitoring from January 28 to March 7, 2004. The USGS investigation identified two earthquake hazards in Oceano that explain the San Simeon earthquake damage?site amplification and liquefaction. Site amplification is a phenomenon observed in many earthquakes where the strength of the shaking increases abnormally in areas where the seismic-wave velocity of shallow geologic layers is low. As a result, earthquake shaking is felt more strongly than in surrounding areas without similar geologic conditions. Site amplification in Oceano is indicated by the physical properties of the geologic layers beneath Oceano and was confirmed by monitoring aftershocks. Liquefaction, which is also commonly observed during earthquakes, is a phenomenon where saturated sands lose their strength during an earthquake and become fluid-like and mobile. As a result, the ground may undergo large permanent displacements that can damage underground utilities and well-built surface structures. The type of displacement of major concern associated with liquefaction is lateral spreading because it involves displacement of large blocks of ground down gentle slopes or towards stream channels. The USGS investigation indicates that the shallow geologic units beneath Oceano are very susceptible to liquefaction. They include young sand dunes and clean sandy artificial fill that was used to bury and convert marshes into developable lots. Most of

  2. Age and significance of earthquake-induced liquefaction near Vancouver, British Columbia, Canada

    Science.gov (United States)

    Clague, J.J.; Naesgaard, E.; Nelson, A.R.

    1997-01-01

    In late 1994, sand dykes, large sand blows, and deformed strata were exposed in the walls of an excavation at Annacis Island on the Fraser River delta near Vancouver, British Columbia. The features record liquefaction during a large earthquake about 1700 years ago; this was perhaps the largest earthquake to affect the Vancouver area in the last 3500 years. Similar, less well-dated features have been reported from several other sites on the Fraser delta and may be products of the same earthquake. Three radiocarbon ages that closely delimit the time of liquefaction on Annacis Island are similar to the most precise radiocarbon ages on coseismically subsided marsh soils at estuaries in southern Washington and Oregon. Both the liquefaction and the subsidence may have been produced by a single great plate-boundary earthquake at the Cascadia subduction zone. Alternatively, liquefaction at Annacis Island may have been caused by a large crustal or subcrustal earthquake of about the same age as a plate-boundary earthquake farther west. The data from Annacis Island and other sites on the Fraser delta suggest that earthquakes capable of producing extensive liquefaction in this area are rare events. Further, liquefaction analysis using historical seismicity suggests that current assessment procedures may overestimate liquefaction risk.

  3. The "SABEIS" Project: Warning systems based on earthquake and tsunamis-induced ionospheric effects.

    Science.gov (United States)

    Rodriguez-Bouza, Marta; Sánchez-Dulcet, Francisco; Herraiz, Miguel; Rodríguez-Caderot, Gracia; Altadill, David; Blanch, Estefania; Santoyo, Miguel Angel

    2016-04-01

    The study of a possible lithosphere-atmosphere-ionosphere coupling (LAI) is mainly focused on the analysis and comprehension of atmospheric and ionospheric anomalies caused by extreme lithospheric events. In this context, earthquakes are considered as possible sources of atmosphere-ionosphere anomalies. The goal of the two-year long project SABEIS (Sistemas de Alerta Basados en Efectos de terremotos y tsunamis en la IonoSfera) granted by the Spanish Ministry of Economy and Competitiveness, is to analyze the disturbances caused by earthquakes and tsunamis and their possible contribution to warning systems. These topics are receiving increased attention in the scientific community and their correct understanding can meaningfully contribute to the protection of people and economic assets in areas subject to seismic threat. The project is based on the analysis of Total Electron Content (TEC) obtained from signals of Global Navigation Satellite Systems (GNSS) and anomalies of the ionospheric F2 layer observed in ionograms. This methodology was partially applied in a previous study of the Mw6.1 earthquake in Greece occurred on January 26, 2014. In that case two TEC disturbances were detected the days prior the earthquake. The first one, four days before, was registered by the majority of the stations analyzed over Europe and after studying its temporal variation, was considered unrelated to the earthquake. The second one occurred the day before the earthquake. This anomaly appeared only at stations close to the epicenter and their temporal proximity to the earthquake point to a possible connection with the earthquake preparation process. In the SABEIS project possible anomalies caused by earthquakes in Mexico and Peru with magnitude ranging from 5.5 to 8.2, will be studied. If the results confirm the influence of seismic events on the ionosphere, the possibility of incorporating this type of analysis in a seismic alert network for the Gulf of Cadiz (southern Iberian

  4. Moment tensor inversion of ground motion from mining-induced earthquakes, Trail Mountain, Utah

    Science.gov (United States)

    Fletcher, Joe B.; McGarr, A.

    2005-01-01

    A seismic network was operated in the vicinity of the Trail Mountain mine, central Utah, from the summer of 2000 to the spring of 2001 to investigate the seismic hazard to a local dam from mining-induced events that we expect to be triggered by future coal mining in this area. In support of efforts to develop groundmotion prediction relations for this situation, we inverted ground-motion recordings for six mining-induced events to determine seismic moment tensors and then to estimate moment magnitudes M for comparison with the network coda magnitudes Mc. Six components of the tensor were determined, for an assumed point source, following the inversion method of McGarr (1992a), which uses key measurements of amplitude from obvious features of the displacement waveforms. When the resulting moment tensors were decomposed into implosive and deviatoric components, we found that four of the six events showed a substantial volume reduction, presumably due to coseismic closure of the adjacent mine openings. For these four events, the volume reduction ranges from 27% to 55% of the shear component (fault area times average slip). Radiated seismic energy, computed from attenuation-corrected body-wave spectra, ranged from 2.4 ?? 105 to 2.4 ?? 106 J for events with M from 1.3 to 1.8, yielding apparent stresses from 0.02 to 0.06 MPa. The energy released for each event, approximated as the product of volume reduction and overburden stress, when compared with the corresponding seismic energies, revealed seismic efficiencies ranging from 0.5% to 7%. The low apparent stresses are consistent with the shallow focal depths of 0.2 to 0.6 km and rupture in a low stress/low strength regime compared with typical earthquake source regions at midcrustal depths.

  5. Structure of the Koyna-Warna Seismic Zone, Maharashtra, India: A possible model for large induced earthquakes elsewhere

    Science.gov (United States)

    Catchings, Rufus D.; Dixit, M.M.; Goldman, Mark R.; Kumar, S.

    2015-01-01

    The Koyna-Warna area of India is one of the best worldwide examples of reservoir-induced seismicity, with the distinction of having generated the largest known induced earthquake (M6.3 on 10 December 1967) and persistent moderate-magnitude (>M5) events for nearly 50 years. Yet, the fault structure and tectonic setting that has accommodated the induced seismicity is poorly known, in part because the seismic events occur beneath a thick sequence of basalt layers. On the basis of the alignment of earthquake epicenters over an ~50 year period, lateral variations in focal mechanisms, upper-crustal tomographic velocity images, geophysical data (aeromagnetic, gravity, and magnetotelluric), geomorphic data, and correlation with similar structures elsewhere, we suggest that the Koyna-Warna area lies within a right step between northwest trending, right-lateral faults. The sub-basalt basement may form a local structural depression (pull-apart basin) caused by extension within the step-over zone between the right-lateral faults. Our postulated model accounts for the observed pattern of normal faulting in a region that is dominated by north-south directed compression. The right-lateral faults extend well beyond the immediate Koyna-Warna area, possibly suggesting a more extensive zone of seismic hazards for the central India area. Induced seismic events have been observed many places worldwide, but relatively large-magnitude induced events are less common because critically stressed, preexisting structures are a necessary component. We suggest that releasing bends and fault step-overs like those we postulate for the Koyna-Warna area may serve as an ideal tectonic environment for generating moderate- to large- magnitude induced (reservoir, injection, etc.) earthquakes.

  6. 汶川地震次生泥石流形成模式与机理%Formation mode and mechanism for debris flow induced by Wenchuan earthquake

    Institute of Scientific and Technical Information of China (English)

    杨成林; 陈宁生; 李战鲁

    2011-01-01

    以汶川地震灾区的典型的代表性泥石流案例为基础,分析了汶川地震次生泥石流的形成地形地貌、降水和土源条件特征,概括分析了汶川地震泥石流形成的5种模式,即:(1)沟床启动型;(2)坡面崩滑转化型;(3)震裂表土侵蚀启动型;(4)滑坡表面土体液化型和(5)松散坡积物冲切沟启动型.分析了这些形成模式的启动机理.地震次生泥石流的形成机理包括土力类和水力类.泥石流的形成需要一定的细颗粒含量,尤其是粘土颗粒含量;此外低密度干燥度较高的土体在降雨作用下易湿陷,体积收缩,从而有利于土体孔隙水压力的升高,而有利土体强度的降低,导致泥石流的启动.所以地震灾区的泥石流集中分布于干旱河谷松散固体物质大量存在且以花岗岩风化壳和碎屑岩及其变质岩为主的地区,降雨量特征与国内外众多泥石流的降雨特征可以比较,其模式多样.%This paper is based on combination study of the "5. 12" Wenchuan earthquake-induced typical debris flow events. In the paper the debris flow landscape and landform, the precipitation and the earth condition were studied firstly. After that the Wenchuan earthquake debris flow-triggering models were revealed. These models include (1 ) valley triggering; (2)slope collapse and landslide triggering; (3)loose soil eroded by stream and rains; (4)landslide surface liquefied; (5) gully eroded. And the debris flow-triggering mechanism was explained at last. The debris flows of quake - stricken area distribute in the arid valley which abounds in weathered crust granite, clastic rock and metamorphic rock, and the precipitation nodes

  7. Interaction between mDia1 and ROCK in Rho-induced migration and adhesion of human dental pulp cells.

    Science.gov (United States)

    Cheng, L; Xu, J; Qian, Y Y; Pan, H Y; Yang, H; Shao, M Y; Cheng, R; Hu, T

    2017-01-01

    To investigate the effects of mammalian homologue of Drosophila diaphanous-1(mDia1) and Rho-associated coiled-coil-containing protein kinase (ROCK) on the migration and adhesion of dental pulp cells (DPCs). Lysophosphatidic acid (LPA) was used to activate Rho signalling. mDia1 and ROCK were inhibited by short interfering RNA and the specific inhibitor, Y-27632, respectively. The migration of DPCs was assessed using the transwell migration assay and scratch test. Formation of cytoskeleton and focal adhesions(FAs) was observed by confocal laser scanning microscopy. Cell adhesion and spreading assays were performed. Phosphorylation of focal adhesion kinase (FAK) and paxillin was detected by Western blotting, and the bands were analysed using Adobe Photoshop CS5 software. All experiments were performed at least three times, and data were analysed with one-way anova and a post hoc test. LPA-triggered activation of Rho and inhibition of ROCK significantly increased the cell migration rate. Cell migration was inhibited by silencing mDia1. mDia1 silencing and ROCK inhibition suppressed the LPA-induced formation of the cytoskeleton, FA and phosphorylation of FAK and paxillin. Inhibition of ROCK or mDia1 facilitated early cell adhesion and spreading; by contrast, the combined inhibition of ROCK and mDia1 neutralized these effects. mDia1 promoted RhoA-induced migration of DPCs, but ROCK had an opposite effect. Both mDia1 and ROCK participated in cytoskeleton formation and adhesion of DPCs. The interactions between mDia1 and ROCK might influence dental pulp repair by determining the migration and adhesion of DPCs. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  8. Types,Active Characteristics and Development Trend of Rainfall-induced Landslides After Wenchuan Earthquake%汶川地震震后降雨滑坡的类型、活动特征及发展趋势

    Institute of Scientific and Technical Information of China (English)

    裴来政; 周小军; 方华

    2012-01-01

    汶川地震造成许多山体的整体性破坏,部分山体后缘出现裂缝,岩土体在主震作用下产生损伤,边坡稳定性大大降低,在降雨激发作用下极易产生新的滑坡灾害。在分析汶川震后滑坡发育条件变化和降雨滑坡现场调查的基础上,将震后降雨诱发滑坡分为5种类型。震后降雨滑坡的活动特征主要体现在以小型的塌滑最为典型且数量多,沿河道两岸广泛发育,且震区滑坡发生与降雨在时间上具有较强的对应关系,滑坡发生滞后时间短,在强暴雨条件下多为群发型滑坡。从震后降雨滑坡发展趋势来看,初期主要以中小型的滑塌为主,随着时间的推移,小型滑塌数量将逐渐减少,大型、特大型滑坡发生的数量可能会有一定程度的增加。%Under the action of the Wenchuan earthquake,the integrity of some mountains was destroyed and some slits appeared on the mountains.Main shocks caused soils and rocks damaged and its self-strength declined.The quantity of rainfall-induced landslides after the Wenchuan earthquake was much more than that before the earthquake.Five types of the landslides caused by the earthquake were classified based on the investigation of rainfall-induced landslides after the Wenchuan earthquake.Active characteristics of rainfall-induced landslides were mainly embodied in the small and tremendous landslides widely developed along rivers and roads.Landslides and rainfall in the area had a better relationship and the delayed-time for the occurrence of landslides was very short.Massive landslides were developed under the condition of intensive rainstorms.In view of the development trend of rainfall-induced landslides,the small and medium landslides are dominant in the early time.However,the number of the small landslides will decrease but large or huge landslides will increase with increasing time.

  9. The ML 3.5 earthquake sequence induced by the hydrothermal energy project in St. Gallen, Switzerland

    Science.gov (United States)

    Kraft, T.; Wiemer, S.; Deichmann, N.; Diehl, T.; Edwards, B.; Guilhem, A.; Haslinger, F.; Király, E.; Kissling, E. H.; Mignan, A.; Plenkers, K.; Roten, D.; Seif, S.; Woessner, J.

    2013-12-01

    within a few days but two weeks later was still far from reaching the background level. Here we report on the results of our analysis of the induced seismic sequence at Sankt Gallen: ML 3.5 event initiated near the borehole, had a comparatively low stress drop (3.5 bar) and a rupture length of ~1.1 km. Peak ground motions observed for the ML 3.5 eventare very similar to the ones observed in the ML 3.4 event induced in 2006 in Basel. Yet, macroseismic intensities in St. Gallen only reach IV (EMS) versus V (EMS) in Basel. Precise earthquake relative locations indicate that seismicity extends bi-laterally from the injection point, following the trend of the mapped fault segments. Fault plane solutions of the two largest events indicate a left lateral strike slip fault whose orientation agrees well with the aftershock locations and the imaged fault zone. The St. Gallen sequence shows the highest seismic productivity per injected fluid volume when compared to other injection-induced sequences, and challenges proposed relations between injected fluid volume and maximum observed magnitude or between hydraulic energy and released seismic energy.

  10. A study of earthquake-induced building detection by object oriented classification approach

    Science.gov (United States)

    Sabuncu, Asli; Damla Uca Avci, Zehra; Sunar, Filiz

    2017-04-01

    Among the natural hazards, earthquakes are the most destructive disasters and cause huge loss of lives, heavily infrastructure damages and great financial losses every year all around the world. According to the statistics about the earthquakes, more than a million earthquakes occur which is equal to two earthquakes per minute in the world. Natural disasters have brought more than 780.000 deaths approximately % 60 of all mortality is due to the earthquakes after 2001. A great earthquake took place at 38.75 N 43.36 E in the eastern part of Turkey in Van Province on On October 23th, 2011. 604 people died and about 4000 buildings seriously damaged and collapsed after this earthquake. In recent years, the use of object oriented classification approach based on different object features, such as spectral, textural, shape and spatial information, has gained importance and became widespread for the classification of high-resolution satellite images and orthophotos. The motivation of this study is to detect the collapsed buildings and debris areas after the earthquake by using very high-resolution satellite images and orthophotos with the object oriented classification and also see how well remote sensing technology was carried out in determining the collapsed buildings. In this study, two different land surfaces were selected as homogenous and heterogeneous case study areas. In the first step of application, multi-resolution segmentation was applied and optimum parameters were selected to obtain the objects in each area after testing different color/shape and compactness/smoothness values. In the next step, two different classification approaches, namely "supervised" and "unsupervised" approaches were applied and their classification performances were compared. Object-based Image Analysis (OBIA) was performed using e-Cognition software.

  11. Quantitative description of induced seismic activity before and after the 2011 Tohoku-Oki earthquake by nonstationary ETAS models

    Science.gov (United States)

    Kumazawa, Takao; Ogata, Yosihiko

    2013-12-01

    The epidemic-type aftershock sequence (ETAS) model is extended for application to nonstationary seismic activity, including transient swarm activity or seismicity anomalies, in a seismogenic region. The time-dependent rates of both background seismicity and aftershock productivity in the ETAS model are optimally estimated from hypocenter data. These rates can provide quantitative evidence for abrupt or gradual changes in shear stress and/or fault strength due to aseismic transient causes such as triggering by remote earthquakes, slow slips, or fluid intrusions within the region. This extended model is applied to data sets from several seismic events including swarms that were induced by the M9.0 Tohoku-Oki earthquake of 2011.

  12. Acute changes of blood pressure and heart rate induced by a strong earthquake

    Institute of Scientific and Technical Information of China (English)

    HE Sen; CHEN Xiao-ping; LI Jiang-bo; LIN Jian-lan; LUO Xue-ju; LUO Xiao-jia

    2010-01-01

    @@ A high death toll during an earthquake comes not only from injuries related to the destruction of buildings or road accidents but also from sudden death resulting from cardiovascular problems, as clearly shown in reports.~(1,2) The increased rate of cardiovascular mortality during an earthquake has been ascribed to the impact of a major emotional stress on the heart, mediated through an increase in cardiac sympathetic activity~,(1,2) and probably including some other neuroendocrine mechanisms. A rise in blood pressure (BP) and heart rate (HR) may be directly responsible for the increased rate of cardiovascular mortality during an earthquake. Previously published studies about the acute changes of BP and HR used indirect information, usually collected after the events. A little direct information, such as by Parati et al,~3 is not enough for the low-incidence rate of an earthquake and has the obvious technical difficulties in measuring BP during an earthquake. Luckily, we recorded the acute changes of BP and HR of some patients during the earthquake by 24-hour ambulatory blood pressure monitoring, as report below.

  13. An in-situ stimulation experiment in crystalline rock - assessment of induced seismicity levels during stimulation and related hazard for nearby infrastructure

    Science.gov (United States)

    Gischig, Valentin; Broccardo, Marco; Amann, Florian; Jalali, Mohammadreza; Esposito, Simona; Krietsch, Hannes; Doetsch, Joseph; Madonna, Claudio; Wiemer, Stefan; Loew, Simon; Giardini, Domenico

    2016-04-01

    A decameter in-situ stimulation experiment is currently being performed at the Grimsel Test Site in Switzerland by the Swiss Competence Center for Energy Research - Supply of Electricity (SCCER-SoE). The underground research laboratory lies in crystalline rock at a depth of 480 m, and exhibits well-documented geology that is presenting some analogies with the crystalline basement targeted for the exploitation of deep geothermal energy resources in Switzerland. The goal is to perform a series of stimulation experiments spanning from hydraulic fracturing to controlled fault-slip experiments in an experimental volume approximately 30 m in diameter. The experiments will contribute to a better understanding of hydro-mechanical phenomena and induced seismicity associated with high-pressure fluid injections. Comprehensive monitoring during stimulation will include observation of injection rate and pressure, pressure propagation in the reservoir, permeability enhancement, 3D dislocation along the faults, rock mass deformation near the fault zone, as well as micro-seismicity. The experimental volume is surrounded by other in-situ experiments (at 50 to 500 m distance) and by infrastructure of the local hydropower company (at ~100 m to several kilometres distance). Although it is generally agreed among stakeholders related to the experiments that levels of induced seismicity may be low given the small total injection volumes of less than 1 m3, detailed analysis of the potential impact of the stimulation on other experiments and surrounding infrastructure is essential to ensure operational safety. In this contribution, we present a procedure how induced seismic hazard can be estimated for an experimental situation that is untypical for injection-induced seismicity in terms of injection volumes, injection depths and proximity to affected objects. Both, deterministic and probabilistic methods are employed to estimate that maximum possible and the maximum expected induced

  14. Noise-induced cochlear F-actin depolymerization is mediated via ROCK2/p-ERM signaling.

    Science.gov (United States)

    Han, Yu; Wang, Xianren; Chen, Jun; Sha, Su-Hua

    2015-06-01

    Our previous work has suggested that traumatic noise activates Rho-GTPase pathways in cochlear outer hair cells (OHCs), resulting in cell death and noise-induced hearing loss (NIHL). In this study, we investigated Rho effectors, Rho-associated kinases (ROCKs), and the targets of ROCKs, the ezrin-radixin-moesin (ERM) proteins, in the regulation of the cochlear actin cytoskeleton using adult CBA/J mice under conditions of noise-induced temporary threshold shift (TTS) and permanent threshold shift (PTS) hearing loss, which result in changes to the F/G-actin ratio. The levels of cochlear ROCK2 and p-ERM decreased 1 h after either TTS- or PTS-noise exposure. In contrast, ROCK2 and p-ERM in OHCs decreased only after PTS-, not after TTS-noise exposure. Treatment with lysophosphatidic acid, an activator of the Rho pathway, resulted in significant reversal of the F/G-actin ratio changes caused by noise exposure and attenuated OHC death and NIHL. Conversely, the down-regulation of ROCK2 by pretreatment with ROCK2 siRNA reduced the expression of ROCK2 and p-ERM in OHCs, exacerbated TTS to PTS, and worsened OHC loss. Additionally, pretreatment with siRNA against radixin, an ERM protein, aggravated TTS to PTS. Our results indicate that a ROCK2-mediated ERM-phosphorylation signaling cascade modulates noise-induced hair cell loss and NIHL by targeting the cytoskeleton. We propose the following cascade following noise trauma leading to alteration of the F-actin arrangement in the outer hair cell cytoskeleton: Noise exposure reduces the levels of GTP-RhoA and subsequently diminishes levels of RhoA effector ROCK2 (Rho-associated kinase 2). Phosphorylation of ezrin-radixin-moesin (ERM) by ROCK2 normally allows ERM to cross-link actin filaments with the plasma membrane. Noise-decreased levels of ROCK results in reduction of phosphorylation of ERM that leads to depolymerization of actin filaments. Lysophosphatidic acid (LPA), an agonist of RhoA, binds to the G-protein-coupled receptor

  15. A contribution for predicting Tsunami inundation induced by rock fall along the Gaeta cliff (Central Italy)

    Science.gov (United States)

    di Manna, P.; Vittori, E.; Comerci, V.; Amanti, M.; Cesi, C.

    2009-04-01

    Many sectors of Italian coasts are characterized by tall scarps, close to large or pocket beaches that display ramp shape with moderate to low acclivity profile. During the summer, all these beaches are densely populated by sunbathers. Moreover, Italian coastal areas are often intensely urbanized even at a short distance from the sea and very close to sea level. Being cliffs often affected by gravity processes, the impact on the water of a falling volume of rock, depending on size and height of fall, may represent a potential source of tsunami-type hazard for adjacent beaches and boats. In this work we present an attempt to evaluate the run-up and ingression values in the Serapo beach (Gaeta, Tyrrhenian Sea coast of Central Italy) of an anomalous wave induced by a potential rock fall along the contiguous more than 100 meters high limestone cliff (the so-called Montagna Spaccata, "cleft mountain"). Detailed geological and geomorphological field analyses are being carried out, including geomechanical analyses and geodetic monitoring, in order to recognize the sectors with the most critical stability conditions. Preliminarily, the major potential volume of instable block and its most likely kinematics have been estimated with the purpose of characterizing the rock fall process. The first water rise produced by the impact of the rock on the sea surface has been estimated according to two approaches: a) the Murty (2003) equation, that gives the relation between water elevation and volume of fallen material; b) the Glasstone and Dolan method (Hills & Mader, 1997), comparing the carbonate rock fall to a meteoritic impact on the sea surface. The rockfall kinematics suggests that the Glasstone and Dolan equation, despite it was developed for a different environment, is better applicable than Murty's (valid for slides) to the case under discussion. On the basis of the Green's law (1837) we defined the shoaling component of the run-up values. Our results show that the impact

  16. Superconducting Gravimeters Detect Gravity Fluctuations Induced by Mw 5.7 Earthquake Along South Pacific Rise Few Hours Before the 2011 Mw 9.0 Tohoku-Oki Earthquake

    Directory of Open Access Journals (Sweden)

    Keliang Zhang Jin Ma

    2014-01-01

    Full Text Available Gravity changes sometimes appear before a big earthquake. To determine the possible sources is important for recognizing the mechanism and further geodynamic studies. During the first two hours on March 11 before the Mw 9.0 Tohoku-Oki earthquake, the non-tidal gravity time series of superconducting gravimeters worldwide showed low-frequency (< 0.10 Hz fluctuations with amplitude of ~1 to 4 × 10-8 ms-2 lasting ~10 - 20 minutes. Through comparing global seismicity with the arrival times of seismic waves, we find that the fluctuations were induced by the Mw 5.7 earthquake that occurred at 0:14:54.68 at (53.27°S, 118.18°W along the eastern South Pacific Rise. Several body waves such as P, S are clearly recorded in the station with ~400 km distance to the hypocenter. The fluctuations are in response to the waves that propagate with a velocity of about 4 km s-1. Their amplitudes are proportional to the inverse of the epicentral distances even though the fluctuations of European sites were overlapped with waves associated with a smaller, i.e., Mw 2.6, event in Europe during this period. That is, the Mw 5.7 earthquake induced remarkable gravity fluctuations over long distances at stations all over the world. As such, the foreshocks with larger magnitudes occurred before the Mw 9.0 earthquake would have more significant influence on the gravity recordings and the seismic-wave induced component should be removed during the analysis of anomalies prior to a great earthquake in future studies.

  17. Superconducting Gravimeters Detect Gravity Fluctuations Induced by Mw 5.7 Earthquake Along South Pacific Rise Few Hours Before the 2011 Mw 9.0 Tohoku-Oki Earthquake

    Directory of Open Access Journals (Sweden)

    Keliang Zhang and Jin Ma

    2014-01-01

    Full Text Available Gravity changes sometimes appear before a big earthquake. To determine the possible sources is important for recognizing the mechanism and further geodynamic studies. During the first two hours on March 11 before the Mw 9.0 Tohoku-Oki earthquake, the non-tidal gravity time series of superconducting gravimeters worldwide showed low-frequency (< 0.10 Hz fluctuations with amplitude of ~1 to 4 ×× 10-8 ms-2 lasting ~10 - 20 minutes. Through comparing global seismicity with the arrival times of seismic waves, we find that the fluctuations were induced by the Mw 5.7 earthquake that occurred at 0:14:54.68 at (53.27°S,(53.27°S, 118.18°W118.18°W along the eastern South Pacific Rise. Several body waves such as P, S are clearly recorded in the station with ~400 km distance to the hypocenter. The fluctuations are in response to the waves that propagate with a velocity of about 4 km s-1. Their amplitudes are proportional to the inverse of the epicentral distances even though the fluctuations of European sites were overlapped with waves associated with a smaller, i.e., Mw 2.6, event in Europe during this period. That is, the Mw 5.7 earthquake induced remarkable gravity fluctuations over long distances at stations all over the world. As such, the foreshocks with larger magnitudes occurred before the Mw 9.0 earthquake would have more significant influence on the gravity recordings and the seismic-wave induced component should be removed during the analysis of anomalies prior to a great earthquake in future studies.

  18. Tracking Down the Causes of Recent Induced and Natural Intraplate Earthquakes with 3D Seismological Analyses in Northwest Germany

    Science.gov (United States)

    Uta, P.; Brandes, C.; Boennemann, C.; Plenefisch, T.; Winsemann, J.

    2015-12-01

    Northwest Germany is a typical low strain intraplate region with a low seismic activity. Nevertheless, 58 well documented earthquakes with magnitudes of 0.5 - 4.3 affected the area in the last 40 years. Most of the epicenters were located in the vicinity of active natural gas fields and some inside. Accordingly, the earthquakes were interpreted as a consequence of hydrocarbon recovery (e.g. Dahm et al. 2007, Bischoff et al. 2013) and classified as induced events in the bulletins of the Federal Institute for Geosciences and Natural Resources (BGR). The two major ones have magnitudes of 4.3 and 4.0. They are the strongest earthquakes ever recorded in Northern Germany. Consequently, these events raise the question whether the ongoing extraction itself can cause them or if other natural tectonic processes like glacial isostatic adjustment may considerably contribute to their initiation. Recent studies of Brandes et al. (2012) imply that lithospheric stress changes due to post glacial isostatic adjustment might be also a potential natural cause for earthquakes in Central Europe. In order to better analyse the earthquakes and to test this latter hypothesis we performed a relocalization of the events with the NonLinLoc (Lomax et al. 2000) program package and two differently scaled 3D P-wave velocity models. Depending on the station coverage for a distinct event, either a fine gridded local model (88 x 73 x 15 km, WEG-model, made available by the industry) or a coarse regional model (1600 x 1600 x 45 km, data from CRUST1.0, Laske et al. 2013) and for some cases a combination of both models was used for the relocalization. The results confirm the trend of the older routine analysis: The majority of the events are located at the margins of the natural gas fields, some of them are now located closer to them. Focal depths mostly vary between 3.5 km and 10 km. However, for some of the events, especially for the older events with relatively bad station coverage, the error bars

  19. Moderate-magnitude earthquakes induced by magma reservoir inflation at Kīlauea Volcano, Hawai‘i

    Science.gov (United States)

    Wauthier, Christelle; Roman, Diana C.; Poland, Michael P.

    2013-01-01

    Although volcano-tectonic (VT) earthquakes often occur in response to magma intrusion, it is rare for them to have magnitudes larger than ~M4. On 24 May 2007, two shallow M4+ earthquakes occurred beneath the upper part of the east rift zone of Kīlauea Volcano, Hawai‘i. An integrated analysis of geodetic, seismic, and field data, together with Coulomb stress modeling, demonstrates that the earthquakes occurred due to strike-slip motion on pre-existing faults that bound Kīlauea Caldera to the southeast and that the pressurization of Kīlauea's summit magma system may have been sufficient to promote faulting. For the first time, we infer a plausible origin to generate rare moderate-magnitude VTs at Kīlauea by reactivation of suitably oriented pre-existing caldera-bounding faults. Rare moderate- to large-magnitude VTs at Kīlauea and other volcanoes can therefore result from reactivation of existing fault planes due to stresses induced by magmatic processes.

  20. Earthquake induced liquefaction hazard, probability and risk assessment in the city of Kolkata, India: its historical perspective and deterministic scenario

    Science.gov (United States)

    Nath, Sankar Kumar; Srivastava, Nishtha; Ghatak, Chitralekha; Adhikari, Manik Das; Ghosh, Ambarish; Sinha Ray, S. P.

    2017-09-01

    Liquefaction-induced ground failure is one amongst the leading causes of infrastructure damage due to the impact of large earthquakes in unconsolidated, non-cohesive, water saturated alluvial terrains. The city of Kolkata is located on the potentially liquefiable alluvial fan deposits of Ganga-Bramhaputra-Meghna Delta system with subsurface litho-stratigraphic sequence comprising of varying percentages of clay, cohesionless silt, sand, and gravel interbedded with decomposed wood and peat. Additionally, the region has moderately shallow groundwater condition especially in the post-monsoon seasons. In view of burgeoning population, there had been unplanned expansion of settlements in the hazardous geological, geomorphological, and hydrological conditions exposing the city to severe liquefaction hazard. The 1897 Shillong and 1934 Bihar-Nepal earthquakes both of M w 8.1 reportedly induced Modified Mercalli Intensity of IV-V and VI-VII respectively in the city reportedly triggering widespread to sporadic liquefaction condition with surface manifestation of sand boils, lateral spreading, ground subsidence, etc., thus posing a strong case for liquefaction potential analysis in the terrain. With the motivation of assessing seismic hazard, vulnerability, and risk of the city of Kolkata through a consorted federal funding stipulated for all the metros and upstart urban centers in India located in BIS seismic zones III, IV, and V with population more than one million, an attempt has been made here to understand the liquefaction susceptibility condition of Kolkata under the impact of earthquake loading employing modern multivariate techniques and also to predict deterministic liquefaction scenario of the city in the event of a probabilistic seismic hazard condition with 10% probability of exceedance in 50 years and a return period of 475 years. We conducted in-depth geophysical and geotechnical investigations in the city encompassing 435 km2 area. The stochastically

  1. Analysis of the relationship between landslides size distribution and earthquake source area

    Science.gov (United States)

    Valagussa, Andrea; Crosta, Giovanni B.; Frattini, Paolo; Xu, Chong

    2014-05-01

    The spatial distribution of earthquake induced landslides around the seismogenetic source has been analysed to better understand the triggering of landslides in seismic areas and to forecast the maximum distance at which an earthquake, with a certain magnitude, can induce landslides (e.g Keefer, 1984). However, when applying such approaches to old earthquakes (e.g 1929 Buller and 1968 Iningahua earthquakes New Zealand; Parker, 2013; 1976 Friuli earthquake, Italy) one should be concerned about the undersampling of smaller landslides which can be cancelled by erosion and landscape evolution. For this reason, it is important to characterize carefully the relationship between landslide area and number with distance from the source, but also the size distribution of landslides as a function of distance from the source. In this paper, we analyse the 2008 Wenchuan earthquake landslide inventory (Xu et al, 2013). The earthquake triggered more than 197,000 landslides of different type, including rock avalanches, rockfalls, translational and rotational slides, lateral spreads and derbies flows. First, we calculated the landslide intensity (number of landslides per unit area) and spatial density (landslide area per unit area) as a function of distance from the source area of the earthquake. Then, we developed magnitude frequency curves (MFC) for different distances from the source area. Comparing these curves, we can describe the relation between the distance and the frequency density of landslide in seismic area. Keefer D K (1984) Landslides caused by earthquakes. Geological Society of America Bulletin, 95(4), 406-421. Parker R N, (2013) Hillslope memory and spatial and temporal distributions of earthquake-induced landslides, Durham theses, Durham University. Xu, C., Xu, X., Yao, X., & Dai, F. (2013). Three (nearly) complete inventories of landslides triggered by the May 12, 2008 Wenchuan Mw 7.9 earthquake of China and their spatial distribution statistical analysis

  2. Simulating dam-breach flood scenarios of the Tangjiashan landslide dam induced by the Wenchuan Earthquake

    Directory of Open Access Journals (Sweden)

    X. Fan

    2012-10-01

    Full Text Available Floods from failures of landslide dams can pose a hazard to people and property downstream, which have to be rapidly assessed and mitigated in order to reduce the potential risk. The Tangjiashan landslide dam induced by the Mw = 7.9 2008 Wenchuan earthquake had impounded the largest lake in the earthquake affected area with an estimated volume of 3 × 108 m3, and the potential catastrophic dam breach posed a serious threat to more than 2.5 million people in downstream towns and Mianyang city, located 85 km downstream. Chinese authorities had to evacuate parts of the city until the Tangjiashan landslide dam was artificially breached by a spillway, and the lake was drained. We propose an integrated approach to simulate the dam-breach floods for a number of possible scenarios, to evaluate the severity of the threat to Mianyang city. Firstly, the physically-based BREACH model was applied to predict the flood hydrographs at the dam location, which were calibrated with observational data of the flood resulting from the artificial breaching. The output hydrographs from this model were inputted into the 1-D–2-D SOBEK hydrodynamic model to simulate the spatial variations in flood parameters. The simulated flood hydrograph, peak discharge and peak arrival time at the downstream towns fit the observations. Thus this approach is capable of providing reliable predictions for the decision makers to determine the mitigation plans. The sensitivity analysis of the BREACH model input parameters reveals that the average grain size, the unit weight and porosity of the dam materials are the most sensitive parameters. The variability of the dam material properties causes a large uncertainty in the estimation of the peak flood discharge and peak arrival time, but has little influence on the flood inundation area and flood depth downstream. The effect of cascading breaches of smaller dams downstream of the Tangjiashan dam was

  3. Acoustically-induced slip in sheared granular layers: application to dynamic earthquake triggering

    CERN Document Server

    Ferdowsi, Behrooz; Guyer, Robert A; Johnson, Paul A; Marone, Chris; Carmeliet, Jan

    2015-01-01

    A fundamental mystery in earthquake physics is "how can an earthquake be triggered by distant seismic sources?" A possible explanation is suggested by results found in discrete element method simulations of a granular layer, during stick-slip, that is subject to transient vibrational excitation. We find that at a critical vibrational amplitude (strain) there is an abrupt transition from negligible time-advanced slip (clock advance) to full clock advance, i.e., transient vibration and earthquake are simultaneous. The critical strain is of order 10^{-6}, similar to observations in the laboratory and in Earth. The transition is related to frictional weakening of the granular layer due to a dramatic increase in the number of slipping contacts and decrease in the coordination number. Associated with this frictional weakening is a pronounced decrease in the elastic moduli of the layer.

  4. Berberine ameliorates experimental diabetes-induced renal inflammation and fibronectin by inhibiting the activation of RhoA/ROCK signaling.

    Science.gov (United States)

    Xie, Xi; Chang, Xiuting; Chen, Lei; Huang, Kaipeng; Huang, Juan; Wang, Shaogui; Shen, Xiaoyan; Liu, Peiqing; Huang, Heqing

    2013-12-05

    The accumulation of glomerular extracellular matrix proteins, especially fibronectin (FN), is a critical pathological characteristic of diabetic renal fibrosis. Inflammation mediated by nuclear factor-κB (NF-κB) plays a critical role in the pathogenesis of diabetic nephropathy (DN). RhoA/ROCK signaling is responsible for FN accumulation and NF-κB activation. Berberine (BBR) treatment significantly inhibited renal inflammation and thus improved renal damage in diabetes. Here, we study whether BBR inhibits FN accumulation and NF-κB activation by inhibiting RhoA/ROCK signaling and the underlying mechanisms involved. Results showed that BBR effectively inhibited RhoA/ROCK signaling activation in diabetic rat kidneys and high glucose-induced glomerular mesangial cells (GMCs) and simultaneously down-regulated NF-κB activity, which was accompanied by reduced intercellular adhesionmolecule-1, transforming growth factor-beta 1 and FN overproduction. Furthermore, we observed that BBR abrogated high glucose-mediated reactive oxygen species generation in GMCs. BBR and N-acetylcysteine inhibited RhoA/ROCK signaling activation in high glucose-exposed GMCs. Collectively, our data suggest that the renoprotective effect of BBR on DN partly depends on RhoA/ROCK inhibition. The anti-oxidative stress effect of BBR is responsible for RhoA/ROCK inhibition in DN.

  5. Rock outcrops reduce temperature-induced stress for tropical conifer by decoupling regional climate in the semiarid environment.

    Science.gov (United States)

    Locosselli, Giuliano Maselli; Cardim, Ricardo Henrique; Ceccantini, Gregório

    2016-05-01

    We aimed to understand the effect of rock outcrops on the growth of Podocarpus lambertii within a microrefuge. Our hypothesis holds that the growth and survival of this species depend on the regional climate decoupling provided by rock outcrops. To test this hypothesis, we characterized the microclimate of (1) surrounding vegetation, (2) rock outcrop corridors, and (3) adjacencies. We assessed population structure by collecting data of specimen stem diameter and height. We also assessed differences between vegetation associated or not with outcrops using satellite imaging. For dendrochronological analyses, we sampled 42 individuals. Tree rings of 31 individuals were dated, and climate-growth relationships were tested. Rock outcrops produce a favorable microclimate by reducing average temperature by 4.9 °C and increasing average air humidity by 12 %. They also reduce the variability of atmospheric temperature by 42 % and air humidity by 20 % supporting a vegetation with higher leaf area index. Within this vegetation, specimen height was strongly constrained by the outcrop height. Although temperature and precipitation modulate this species growth, temperature-induced stress is the key limiting growth factor for this population of P. lambertii. We conclude that this species growth and survival depend on the presence of rock outcrops. These topography elements decouple regional climate in a favorable way for this species growth. However, these benefits are restricted to the areas sheltered by rock outcrops. Although this microrefuge supported P. lambertii growth so far, it is unclear whether this protection would be sufficient to withstand the stress of future climate changes.

  6. Wnt3A Induces GSK-3β Phosphorylation and β-Catenin Accumulation Through RhoA/ROCK.

    Science.gov (United States)

    Kim, Jae-Gyu; Kim, Myoung-Ju; Choi, Won-Ji; Moon, Mi-Young; Kim, Hee-Jun; Lee, Jae-Yong; Kim, Jaebong; Kim, Sung-Chan; Kang, Seung Goo; Seo, Goo-Young; Kim, Pyeung-Hyeun; Park, Jae-Bong

    2017-05-01

    In canonical pathway, Wnt3A has been known to stabilize β-catenin through the dissociation between β-catenin and glycogen synthase kinase-3β (GSK-3β) that suppresses the phosphorylation and degradation of β-catenin. In non-canonical signaling pathway, Wnt was known to activate Rho GTPases and to induce cell migration. The cross-talk between canonical and non-canonical pathways by Wnt signaling; however, has not been fully elucidated. Here, we revealed that Wnt3A induces not only the phosphorylation of GSK-3β and accumulation of β-catenin but also RhoA activation in RAW264.7 and HEK293 cells. Notably, sh-RhoA and Tat-C3 abolished both the phosphorylation of GSK-3β and accumulation of β-catenin. Y27632, an inhibitor of Rho-associated coiled coil kinase (ROCK) and si-ROCK inhibited both GSK-3β phosphorylation and β-catenin accumulation. Furthermore, active domain of ROCK directly phosphorylated the purified recombinant GSK-3β in vitro. In addition, Wnt3A-induced cell proliferation and migration, which were inhibited by Tat-C3 and Y27632. Taken together, we propose the cross-talk between canonical and non-canonical signaling pathways of Wnt3A, which induces GSK-3β phosphorylation and β-catenin accumulation through RhoA and ROCK activation. J. Cell. Physiol. 232: 1104-1113, 2017. © 2016 Wiley Periodicals, Inc.

  7. Use of certain geology-engineering and geophysical parameters of rock in certain sectors of Kyzykkum for estimating the increase in earthquake intensity

    Energy Technology Data Exchange (ETDEWEB)

    Dzhuraev, N.M.; Tillyabaev, R.A.; Tuichieva, M.A.

    1979-01-01

    An examination is made of the relationship of increases in earthquake intensity (..delta..I) to density (omicron), velocity (..nu..) and the specific electric resistance (P) of near-surface deposits of the Zarafshan sector. A table of such values is presented. 4 references, 1 table.

  8. Liquefaction-fluidization induced land subsidence: impact of the 2011 Tohoku earthquake on reclaimed land around Tokyo bay area, Japan

    Science.gov (United States)

    Kagawa, A.; Furuno, K.; Kusuda, T.; Sakai, Y.; Yoshida, T.; Kazaoka, O.

    2015-11-01

    The 2011 Tohoku earthquake caused major liquefaction-induced, ground deformation of the reclaimed land surrounding Tokyo Bay. In this area, liquefaction was visibly manifest by sand boils, ejection of sandy water, land subsidence and floating underground tanks. The level measurements show a correspondence between the degree of liquefaction-fluidization and the amount of subsidence. The strata most susceptible to liquefaction are hydraulically emplaced dredged fill and artificial strata on thick uncompacted Holocene deposits. On the other hand, the phenomena of seismic isolation coursed by liquefaction had saved the single-family houses from collapse.

  9. Reassessment of liquefaction potential and estimation of earthquake- induced settlements at Paducah Gaseous Diffusion Plant, Paducah, Kentucky. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sykora, D.W.; Yule, D.E.

    1996-04-01

    This report documents a reassessment of liquefaction potential and estimation of earthquake-induced settlements for the U.S. Department of Energy (DOE), Paducah Gaseous Diffusion Plant (PGDP), located southwest of Paducah, KY. The U.S. Army Engineer Waterways Experiment Station (WES) was authorized to conduct this study from FY91 to FY94 by the DOE, Oak Ridge Operations (ORO), Oak Ridge, TN, through Inter- Agency Agreement (IAG) No. DE-AI05-91OR21971. The study was conducted under the Gaseous Diffusion Plant Safety Analysis Report (GDP SAR) Program.

  10. Effectiveness of Disaster-prevention Technologies against Quake-induced Damage of MR Scanners during the Great East Japan Earthquake.

    Science.gov (United States)

    Yamaguchi-Sekino, Sachiko; Machida, Yoshio; Tsuchihashi, Toshio; Isoda, Haruo; Noguchi, Takashi; Nakai, Toshiharu

    2016-01-01

    In the present study, we have performed a statistical analysis to investigate damages in magnetic resonance (MR) scanners caused by the Great East Japan Earthquake (GEJE, magnitude 9.0) and evaluated whether these disaster-prevention technologies contributed to the reduction of damages in the GEJE or not. It was confirmed that the extent of damage was significantly different between seismic scale (SS) 5 and SS over 6. Our survey study demonstrated that anchoring of MR facilities reduced damages due to quakes and demonstrated that anchoring is an efficient method for quake-induced damage prevention. The odds ratio revealed that base isolation was very useful to prevent damages in MR scanners.

  11. Update of the USGS 2016 One-year Seismic Hazard Forecast for the Central and Eastern United States From Induced and Natural Earthquakes

    Science.gov (United States)

    Petersen, M. D.; Mueller, C. S.; Moschetti, M. P.; Hoover, S. M.; Llenos, A. L.; Ellsworth, W. L.; Michael, A. J.; Rubinstein, J. L.; McGarr, A.; Rukstales, K. S.

    2016-12-01

    The U.S. Geological Survey released a 2016 one-year forecast for seismic hazard in the central and eastern U.S., which included the influence from both induced and natural earthquakes. This forecast was primarily based on 2015 declustered seismicity rates but also included longer-term rates, 10- and 20- km smoothing distances, earthquakes between Mw 4.7 and maximum magnitudes of 6.0 or 7.1, and 9 alternative ground motion models. Results indicate that areas in Oklahoma, Kansas, Colorado, New Mexico, Arkansas, Texas, and the New Madrid Seismic Zone have a significant chance for damaging ground shaking levels in 2016 (greater than 1% chance of exceeding 0.12 PGA and MMI VI). We evaluate this one-year forecast by considering the earthquakes and ground shaking levels that occurred during the first half of 2016 (earthquakes not included in the forecast). During this period the full catalog records hundreds of events with M ≥ 3.0, but the declustered catalog eliminates most of these dependent earthquakes and results in much lower numbers of earthquakes. The declustered catalog based on USGS COMCAT indicates a M 5.1 earthquake occurred in the zone of highest hazard on the map. Two additional earthquakes of M ≥ 4.0 occurred in Oklahoma, and about 82 earthquakes of M ≥ 3.0 occurred with 77 in Oklahoma and Kansas, 4 in Raton Basin Colorado/New Mexico, and 1 near Cogdell Texas. In addition, 72 earthquakes occurred outside the zones of induced seismicity with more than half in New Madrid and eastern Tennessee. The catalog rates in the first half of 2016 and the corresponding seismic hazard were generally lower than in 2015. For example, the zones for Irving, Venus, and Fashing, Texas; Sun City, Kansas; and north-central Arkansas did not experience any earthquakes with M≥ 2.7 during this period. The full catalog rates were lower by about 30% in Raton Basin and the Oklahoma-Kansas zones but the declustered catalog rates did not drop as much. This decrease in earthquake

  12. Fyn Mediates High Glucose-Induced Actin Cytoskeleton Reorganization of Podocytes via Promoting ROCK Activation In Vitro

    Directory of Open Access Journals (Sweden)

    Zhimei Lv

    2016-01-01

    Full Text Available Fyn, a member of the Src family of tyrosine kinases, is a key regulator in cytoskeletal remodeling in a variety of cell types. Recent studies have demonstrated that Fyn is responsible for nephrin tyrosine phosphorylation, which will result in polymerization of actin filaments and podocyte damage. Thus detailed involvement of Fyn in podocytes is to be elucidated. In this study, we investigated the potential role of Fyn/ROCK signaling and its interactions with paxillin. Our results presented that high glucose led to filamentous actin (F-actin rearrangement in podocytes, accompanied by paxillin phosphorylation and increased cell motility, during which Fyn and ROCK were markedly activated. Gene knockdown of Fyn by siRNA showed a reversal effect on high glucose-induced podocyte damage and ROCK activation; however, inhibition of ROCK had no significant effects on Fyn phosphorylation. These observations demonstrate that in vitro Fyn mediates high glucose-induced actin cytoskeleton remodeling of podocytes via promoting ROCK activation and paxillin phosphorylation.

  13. Analysis of propagation mechanisms of stimulation-induced fractures in rocks

    Science.gov (United States)

    Krause, Michael; Renner, Joerg

    2016-04-01

    Effectivity of geothermal energy production depends crucially on the heat exchange between the penetrated hot rock and the circulating water. Hydraulic stimulation of rocks at depth intends to create a network of fractures that constitutes a large area for exchange. Two endmembers of stimulation products are typically considered, tensile hydro-fractures that propagate in direction of the largest principal stress and pre-existing faults that are sheared when fluid pressure reduces the effective normal stress acting on them. The understanding of the propagation mechanisms of fractures under in-situ conditions is still incomplete despite intensive research over the last decades. Wing-cracking has been suggested as a mechanism of fracture extension from pre-existent faults with finite length that are induced to shear. The initiation and extension of the wings is believed to be in tensile mode. Open questions concern the variability of the nominal material property controlling tensile fracture initiation and extension, the mode I facture toughness KIC, with in-situ conditions, e.g., its mean-stress dependence. We investigated the fracture-propagation mechanism in different rocks (sandstones and granites) under varying conditions mimicking those representative for geothermal systems. To determine KIC-values we performed 3-point bending experiments. We varied the confining pressure, the piston velocity, and the position of the chevron notch relative to the loading configuration. Additional triaxial experiments at a range of confining pressures were performed to study wing crack propagation from artificial flaws whose geometrical characteristics, i.e., length, width, and orientation relative to the axial load are varied. We monitored acoustic emissions to constrain the spacio-temporal evolution of the fracturing. We found a significant effect of the length of the artificial flaw and the confining pressure on wing-crack initiation but did not observe a systematic dependence

  14. Dissecting the Mechanisms of Doxorubicin and Oxidative Stress-Induced Cytotoxicity: The Involvement of Actin Cytoskeleton and ROCK1

    Science.gov (United States)

    Wei, Lei; Surma, Michelle; Gough, Gina; Shi, Stephanie; Lambert-Cheatham, Nathan; Chang, Jiang; Shi, Jianjian

    2015-01-01

    We have recently reported that ROCK1 deficiency in mouse embryonic fibroblasts (MEF) has superior anti-apoptotic and pro-survival effects than antioxidants against doxorubicin, a chemotherapeutic drug. Although oxidative stress is the most widely accepted mechanism, our studies suggest that ROCK1-dependent actin cytoskeleton remodeling plays a more important role in mediating doxorubicin cytotoxicity on MEFs. To further explore the contributions of ROCK1-dependent actin cytoskeleton remodeling in response to stress, this study investigates the mechanistic differences between the cytotoxic effects of doxorubicin versus hydrogen peroxide (H2O2), with a focus on cytoskeleton alterations, apoptosis and necrosis induction. We found that both types of stress induce caspase activation but with different temporal patterns and magnitudes in MEFs: H2O2 induces the maximal levels (2 to 4-fold) of activation of caspases 3, 8, and 9 within 4 h, while doxorubicin induces much higher maximal levels (15 to 25-fold) of caspases activation at later time points (16–24 h). In addition, necrosis induced by H2O2 reaches maximal levels within 4 h while doxorubicin-induced necrosis largely occurs at 16–24 h secondary to apoptosis. Moreover, both types of stress induce actin cytoskeleton remodeling but with different characteristics: H2O2 induces disruption of stress fibers associated with cytosolic translocation of phosphorylated myosin light chain (p-MLC) from stress fibers, while doxorubicin induces cortical F-actin formation associated with cortical translocation of p-MLC from central stress fibers. Furthermore, N-acetylcysteine (an antioxidant) is a potent suppressor for H2O2-induced cytotoxic effects including caspase activation, necrosis, and cell detachment, but shows a much reduced inhibition on doxorubicin-induced changes. On the other hand, ROCK1 deficiency is a more potent suppressor for the cytotoxic effects induced by doxorubicin than by H2O2. These results support the

  15. The Role of the Rho/ROCK Pathway in Ang II and TGF-β1-Induced Atrial Remodeling

    Science.gov (United States)

    Lu, Gui-Hua; Xu, Cheng-Gui; Xu, Zhe; Tang, Kai; Cheng, Yun-Jiu; Gao, Xiu-Ren; Wu, Su-Hua

    2016-01-01

    Objectives To study the role of the Rho/ROCK pathway in Ang II and TGF-β1-induced atrial remodeling. Methods and Results A canine atrial fibrillation (AF) model was established by rapid atrial pacing (RAP) of the left atrium. The roles of TGF-β1, the RhoA/ROCK signaling pathway and connective tissue growth factor (CTGF) in atrial remodeling were studied via both in vitro and in vivo experiments. Each of the dogs that received RAP developed persistent AF within 4 weeks. The mRNA expression levels of TGF-β1 (1.32±0.38), Collagen-I(1.33±0.91), CTGF(5.83±3.71), RhoA(1.23±0.57) and ROCK-1 (1.02±0.27) in the left atrium were significantly increased following 4 weeks of RAP. Angiotensin II (Ang II) induced the proliferation of atrial fibroblasts and up-regulated the expression of both CTGF and ROCK-1 in a dose-dependent manner. Simvastatin and Y27632 reversed Ang II-induced CFs proliferation, as well as ROCK-1(0.89±0.05 and 1.27±0.03, respectively) and CTGF (0.87±0.04 and 0.91±0.02, respectively) expression. The expression mRNA of ROCK-1(1.74±0.13) and CTGF (2.28±0.11) can upregulated by TGF-β1, and down-regulated by Simvastatin (1.22±0.03 vs 2.27±0.11), Y27632 (1.01±0.04 vs 1.64±0.03), Los (1.04±0.11 vs 1.26±0.05), respectively. Losartan and Simvastatin attenuated the effects of TGF-β1, inhibited RhoA activity as opposed to RhoA protein expression. Y27632 had no effect on either the expression or the activity of RhoA. Conclusions The increased expression of profibrotic factors (CTGF, ROCK1 and Smad2/3) played an important role in our RAP-induced AF model. Increased atrial profibrotic factors involve the activation of either the TGF-β1/RhoA/ROCK-1 or the TGF-β1/Smad2/3 signaling pathway. PMID:27611832

  16. 2010 and 1997 Earthquakes near Alice, Texas: Were They Induced by Petroleum Production?

    Science.gov (United States)

    Frohlich, C. A.; Brunt, M.; Glidewell, J.

    2011-12-01

    We investigate mb 3.9 earthquakes occurring on 24 March 1997 and 25 April 2010 near Alice, Texas, about 75 km west of Corpus Christi. For the 2010 earthquake we identified P arrivals at seven EarthScope stations situated within ~100 km of the epicentral region and determined a location of 27.72°N, 97.95°W, about 11 km east of the location reported by NEIC, but coincident with the region of highest intensity (MMI V-VI) felt reports. We compare arrivals for observed secondary P- and S-arrivals with predictions from a published Gulf Coast velocity model. At nearby stations the secondary arrivals are much stronger than primary arrivals; the arrival times and the presence of high-amplitude phases traveling at the velocity of the uppermost model layer suggest the focal depth was shallow, 3 km or less. Seismograms at Hockley, Texas, were virtually identical for the 1997 and 2010 Alice earthquakes, and both events had similar felt areas. We thus conclude they occurred at nearly the same location. This location places the Alice earthquakes approximately along the mapped trace of the Vicksburg fault zone and at the depth of the Frio formation, the principal productive member in the Stratton oil and gas field. The Stratton field has produced at least 2.7 trillion cubic feet of gas and about 100 million barrels of oil since production commenced in 1938. These volumes over the areal extent of Stratton field correspond to a pond of oil having a thickness of ~16 cm, and of liquefied natural gas of thickness of about a meter. We conclude it is plausible, although not proven definitively, that production in the Stratton field contributed to the occurrence of the 1997 and 2010 Alice earthquakes.

  17. Mass wasting triggered by the 5 March 1987 Ecuador earthquakes

    Science.gov (United States)

    Schuster, R.L.; Nieto, A.S.; O'Rourke, T. D.; Crespo, E.; Plaza-Nieto, G.

    1996-01-01

    On 5 March 1987, two earthquakes (Ms=6.1 and Ms=6.9) occurred about 25 km north of Reventador Volcano, along the eastern slopes of the Andes Mountains in northeastern Ecuador. Although the shaking damaged structures in towns and villages near the epicentral area, the economic and social losses directly due to earthquake shaking were small compared to the effects of catastrophic earthquake-triggered mass wasting and flooding. About 600 mm of rain fell in the region in the month preceding the earthquakes; thus, the surficial soils had high moisture contents. Slope failures commonly started as thin slides, which rapidly turned into fluid debris avalanches and debris flows. The surficial soils and thick vegetation covering them flowed down the slopes into minor tributaries and then were carried into major rivers. Rock and earth slides, debris avalanches, debris and mud flows, and resulting floods destroyed about 40 km of the Trans-Ecuadorian oil pipeline and the only highway from Quito to Ecuador's northeastern rain forests and oil fields. Estimates of total volume of earthquake-induced mass wastage ranged from 75-110 million m3. Economic losses were about US$ 1 billion. Nearly all of the approximately 1000 deaths from the earthquakes were a consequence of mass wasting and/ or flooding.

  18. Laser-induced Native Fluorescence Detection of Organic Molecules in Hydrothermal Vent Rocks

    Science.gov (United States)

    Harju, E.; Kidd, R. D.; Bhartia, R.; Conrad, P. G.

    2004-12-01

    We have developed a Multi-channel Deep Ultraviolet Excitation (McDuve) fluorescence detector that has been deployed at several Pacific hydrothermal vent sites [1]. The in situ McDuve detector was able to detect organic molecules at the vent site on rock surfaces and in the water, the signatures being distinguishable one from the other. The McDuve fluorescence detector uses a 224.3 nm helium-silver hollow cathode laser to induce native fluorescence from a sample. Spectral separation is achieved with optical band-pass filters which are coupled to photomultiplier tubes (PMTs) for detection. Samples were recovered at the vent sites and returned from the expedition for bench-top analysis for correlation of the McDuve observations with standard analytical tools-GCMS and X-ray diffraction (for mineralogical ID), as well as with a bench-top version of the McDuve fluorescence detector. Here we report the corroborative results of the laboratory studies. Several preserved samples were subjected to 224.3 nm ultraviolet excitation under wet and dry conditions. Organic molecules were detected on the wet samples analyzed in the lab, corroborating the in situ McDuve data. The fluorescence emission wavelengths associated with the detected organic molecules suggest they are 3-5 ring polycyclic aromatic hydrocarbons [2,3]. The samples were also pyrolized at 500 ºC to decompose any organic molecules present and subsequently reanalyzed. This McDuve analysis revealed a significant decrease in laser induced native fluorescence, a result consistent with the pyrolytic decomposition of the organic content of the rock samples. [1] Conrad, P.G., A.L. Lane, R. Bhartia, W. Hug, (March 2004) Optical Detection of Organic Chemical Biosignatures at Hydrothermal Vents 35th Lunar Plan. Sci. XXXV, 2055. [2] Karcher, W. (1985), Spectral Atlas of Polycyclic Aromatic Compounds, vol. I, Kluwer Academic Publishing Company, Dordrecht, Holland. [3] Bhartia, R., McDonald, G.D., Salas, E.C., Hug, W., Reid, R

  19. Some Considerations on a Large Landslide at the Left Bank of the Aratozawa Dam Caused by the 2008 Iwate-Miyagi Intraplate Earthquake

    Science.gov (United States)

    Aydan, Ömer

    2016-06-01

    The scale and impact of rock slope failures are very large and the form of failure differs depending upon the geological structures of slopes. The 2008 Iwate-Miyagi intraplate earthquake induced many large-scale slope failures, despite the magnitude of the earthquake being of intermediate scale. Among large-scale slope failures, the landslide at the left bank of the Aratozawa Dam site is of great interest to specialists of rock mechanics and rock engineering. Although the slope failure was of planar type, the direction of sliding was luckily towards the sub-valley, so that the landslide did not cause great tsunami-like motion of reservoir fluid. In this study, the author attempts to describe the characteristics of the landslide, strong motion and permanent ground displacement induced by the 2008 Iwate-Miyagi intraplate earthquake, which had great effects on the triggering and evolution of the landslide.

  20. Advancements in near real time mapping of earthquake and rainfall induced landslides in the Avcilar Peninsula, Marmara Region

    Science.gov (United States)

    Coccia, Stella

    2014-05-01

    Stella COCCIA (1), Fiona THEOLEYRE (1), Pascal BIGARRE(1) , Semih ERGINTAV(2), Oguz OZEL(3) and Serdar ÖZALAYBEY(4) (1) National Institute of Industrial Environment and Risks (INERIS) Nancy, France, (2) Kandilli Observatory and Earthquake Research Institute (KOERI), Istanbul, Turkey, (3) Istanbul University (IU), Istanbul, Turkey, (4) TUBITAK MAM, Istanbul, Turkey The European Project MARsite (http://marsite.eu/), started in 2012 and leaded by the KOERI, aims to improve seismic risk evaluation and preparedness to face the next dreadful large event expected for the next three decades. MARsite is thus expected to move a "step forward" the most advanced monitoring technologies, and offering promising open databases to the worldwide scientific community in the frame of other European environmental large-scale infrastructures, such as EPOS (http://www.epos-eu.org/ ). Among the 11 work packages (WP), the main aim of the WP6 is to study seismically-induced landslide hazard, by using and improving observing and monitoring systems in geological, hydrogeotechnical and seismic onshore and offshore areas. One of the WP6 specific study area is the Avcilar Peninsula, situated between Kucukcekmece and Buyukcekmece Lakes in the north-west of the region of Marmara. There, more than 400 landslides are located. According to geological and geotechnical investigations and studies, soil movements of this area are related to underground water and pore pressure changes, seismic forces arising after earthquakes and decreasing sliding strength in fissured and heavily consolidated clays. The WP6 includes various tasks and one of these works on a methodology to develop a dynamic system to create combined earthquake and rainfall induced landslides hazard maps at near real time and automatically. This innovative system could be used to improve the prevention strategy as well as in disaster management and relief operations. Base on literature review a dynamic GIS platform is used to combine

  1. Liquefaction-induced settlement, site effects and damage in the vicinity of Yalova City during the 1999 Izmit earthquake, Turkey

    Indian Academy of Sciences (India)

    Ferhat Ozcep; Savas Karabulut; Oguz Özel; Tazegul Ozcep; Nazire İmre; Halil Zarif

    2014-02-01

    Yalova City (Turkey) is in a tectonically active location that is particularly affected by the northern branch of the North Anatolian Fault Zone. Magnitudes 7.4 and 7.2 earthquakes in 1999 caused great destruction in Yalova. The heavy damage to buildings and other civil engineering structures was mainly due to liquefaction-induced settlement and site effects such as resonance and amplification. In the first phase of this study, the soil liquefaction potential index (PL) and the induced soil settlement were estimated. In the second phase, the effects on sites in Yalova soil were investigated using microtremor and earthquake data. The fundamental periods and amplification in soft soil were compared with microtremor data and strong ground motion records obtained by a local array of eight accelerograph stations deployed in Yalova. Thirty-seven ‘single site’ ambient noise measurements were taken in a dense grid of points covering the centre of the city. A comparison between fundamental periods obtained from strong ground motion records and from microtremor measurements showed similarities, in the 0.1–5 Hz range. Finally, soil liquefaction and amplification (or resonance) were divided into regions according to the extent of damage and the geotechnical/geophysical results.

  2. Energy-Based Analysis of Mechanisms of Earthquake-Induced Landslide Using Hilbert-Huang Transform and Marginal Spectrum

    Science.gov (United States)

    Fan, Gang; Zhang, Li-Min; Zhang, Jian-Jing; Ouyang, Fang

    2017-09-01

    Based on the Hilbert-Huang Transform and its marginal spectrum, an energy-based method is proposed to analyse the dynamics of earthquake-induced landslides and a case study is presented to illustrate the proposed method. The results show that the seismic Hilbert energy in the sliding mass of a landslide is larger than that in the sliding bed when subjected to seismic excitations, causing different dynamic responses between the sliding mass and the sliding bed. The seismic Hilbert energy transits from the high-frequency components to the low-frequency components when the seismic waves propagate through the weak zone, causing a nonuniform seismic Hilbert energy distribution in the frequency domain. Shear failure develops first at the crest and toe of the sliding mass due to resonance effects. Meanwhile, the seismic Hilbert energy in the frequency components of 3-5 Hz, which is close to the natural frequency of the slope, is largely dissipated in the initiation and failure processes of the landslide. With the development of dynamic failure, the peak energy transmission ratios in the weak zone decrease gradually. This study offers an energy-based interpretation for the initiation and progression of earthquake-induced landslides with the shattering-sliding failure type.

  3. Simultaneous Sea-Level Oscillations in Japanese Bays Induced by the Tsunami of Nankai-Trough Earthquake

    Science.gov (United States)

    Oishi, Y.; Furumura, T.; Imamura, F.; Yamashita, K.; Sugawara, D.

    2016-12-01

    In this study, we investigate the response of bays to the tsunami of Nankai-trough earthquake based on tsunami simulations and demonstrate the possibility that sea-level oscillation of each bay, which is induced by an incident tsunami, interacts with those of other bays. Several major cities in Japan, including the capital, are located in the bays near the Nankai trough and it is assumed that these cities will be largely affected by the tsunamis caused by recurring large earthquakes at the trough. Therefore, it is very important for these populated cities to understand the mechanism and properties of the tsunami-induced oscillations that continue for a long time in bays to draw up evacuation plans. To investigate the response of bays for various tsunamis that may occur in the Nankai trough area, we distributed the tsunami sources that have the form of a 2-D Gaussian function around the Nankai trough. From simulations with these sources, it was found that strong oscillations of bay water occur when the source is located in the bay itself or when strong oscillations occur in other bays. For example, when the Tosa bay oscillates, the Tokyo bay that is 600 km away from the Tosa bay also oscillates. Among the bays around the Nankai trough, the Suruga bay, the deepest bay in Japan with a 2500-km depth, oscillates more strongly than other bays for most cases. To check the influence of the strong oscillations in the Suruga bay on other bays, we conducted tsunami simulations using a modified topography model in which the Suruga bay is artificially landfilled. As a consequence, the strength of oscillations in the adjacent bays are reduced by 20-30%, suggesting the large influence of the distinguished oscillation of the Suruga bay on these bays. We finally conducted tsunami simulations using the eleven Nankai-trough earthquake scenarios of the Central Disaster Prevention Council (CDPC) of Japan as tsunami sources, and the mutual relation regarding the strengths of

  4. In situ Laser Induced Breakdown Spectroscopy as a tool to discriminate volcanic rocks and magmatic series, Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Roux, C.P.M., E-mail: clement.roux@u-bourgogne.fr [Laboratoire interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47 870, F-21078 Dijon Cedex (France); Rakovský, J.; Musset, O. [Laboratoire interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47 870, F-21078 Dijon Cedex (France); Monna, F. [Laboratoire ARTéHIS, UMR 6298 CNRS-Université de Bourgogne, 6 Boulevard Gabriel, F-21000 Dijon (France); Buoncristiani, J.-F.; Pellenard, P.; Thomazo, C. [Laboratoire Biogéosciences, UMR 6282 CNRS-Université de Bourgogne, 6 Boulevard Gabriel, F-21000 Dijon (France)

    2015-01-01

    This study evaluates the potentialities of a lab-made pLIBS (portable Laser-Induced Breakdown Spectroscopy) to sort volcanic rocks belonging to various magmatic series. An in-situ chemical analysis of 19 atomic lines, including Al, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Na, Si, Sr and Ti, from 21 sampled rocks was performed during a field exploration in Iceland. Iceland was chosen both for the various typologies of volcanic rocks and the rugged conditions in the field in order to test the sturdiness of the pLIPS. Elemental compositions were also measured using laboratory ICP-AES measurements on the same samples. Based on these latter results, which can be used to identify three different groups of volcanic rocks, a classification model was built in order to sort pLIBS data and to categorize unknown samples. Using a reliable statistical scheme applied to LIBS compositional data, the classification capability of the pLIBS system is clearly demonstrated (90–100% success rate). Although this prototype does not provide quantitative measurements, its use should be of particular interest for future geological field investigations. - Highlights: • Portable LIBS applied to field geology • Fast semi-quantitative geochemical analysis of volcanic rocks and magmatic series • Discriminant analysis and statistical treatments for LIBS compositional data.

  5. Self-sealing of excavation induced fractures in clay host rock

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Braunschweig (Germany)

    2015-07-01

    Excavation of an underground repository for disposal of radioactive waste in clay formations generates fractures around the openings, which may act as pathways for water transport and radionuclides migration. Because of the favorable properties of the clay rocks such as the rheological deformability and swelling capability, a recovery process of the excavation damaged zone (EDZ) can be expected due to the combined impact of rock compression, backfill resistance, and clay swelling during the post-closure phase. Another important issue is the impact of gases produced from anoxic corrosion of waste containers and other metallic components within the repository. The EDZ may act as a conduit for preferential gas flow, depending on the extent of the recovery process. For the safety assessment of a repository, the self-sealing behaviour and impact on water and gas transport through the EDZ have to be characterized, understood, and predicted. Recently, GRS has extensively investigated these important issues with various kinds of laboratory and in- situ experiments under relevant repository conditions. Test samples were taken from the Callovo-Oxfordian argillite at Bure in France and the Opalinus clay (shaly facies) at Mont Terri in Switzerland. Major findings are summarized as follows. As observed in laboratory and in-situ, the gas permeabilities of the claystones increase with stress-induced damage by several orders of magnitude from the impermeable state up to high levels of 10{sup -12}-10{sup -13} m{sup 2}. When hydrostatic confining stress is applied and increased, the fractures in the claystones tend to close up, leading to a decrease in gas permeability down to different levels of 10{sup -16}-10{sup -21} m{sup 2} at stresses in a range of 10 to 20 MPa. As water enters and flows through fractures, the clay matrix can take up a great amount of the water and expand into the interstices. Consequently, the hydraulic conductivity decreases dramatically by several orders of

  6. CpG ODN 1668 induce innate and adaptive immune responses in rock bream (Oplegnathus fasciatus) against rock bream iridovirus (RBIV) infection.

    Science.gov (United States)

    Jung, Myung-Hwa; Jung, Sung-Ju

    2017-10-01

    Rock bream iridovirus (RBIV) causes severe mass mortalities in rock bream in Korea. CpG ODN 1668 showed promise as immunoprotective agents against RBIV infection in rock bream. In this study, we assessed innate/adaptive-related gene expression patterns in RBIV-infected rock bream with and without CpG ODN 1668 administration to determine important immune defense related factors that may affect fish survival. In the CpG ODN 1668+virus-injected group, virus copies were more than 7.4- to 790591-fold lower than in the virus-injected group at 4 d (8.79 × 10(4) and 6.58 × 10(5)/μl, respectively), 7 d (5.30 × 10(2) and 2.29 × 10(7)/μl, respectively) and 10 dpi (7.79 × 10(1) and 6.16 × 10(7)/μl, respectively). Furthermore, in the CpG ODN 1668+virus-injected group, significantly higher levels of MyD88 (6 h, 1 d, 4 d and 7 dpi), IL1β (1 d, 2 d and 7 dpi) and perforin/granzyme (1 dpi) expression were observed, whereas these genes were not significantly expressed in the virus-injected group at that time points. Mx, ISG15 and PKR were significantly highly expressed at 4 d and 7 dpi and reduced when low viral loads at 10 dpi in the CpG ODN 1668+virus-injected group. Conversely, in the virus-injected group, Mx, ISG15 and PKR expression were significantly higher than the control group until 10 dpi. However, MHC class I, CD8, Fas, Fas ligand and caspases (3, 8 and 9) expression levels showed no statistically significant differences between virus- and CpG ODN 1668+virus-injected group. In summary, CpG ODN 1668 administration in fish induces innate immune response or cell death pathway, which could be a major contributing factor to effective fish control over viral transcription on 4 d to 10 dpi. Expression of MyD88, IL1β, perforin and granzyme-related immune gene response is critical factor for inhibition of RBIV replication. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Microstructure induced nonlinearity of unconsolidated rocks as related to seismic diagnostic problems

    Directory of Open Access Journals (Sweden)

    I. Yu. Belyaeva

    1997-01-01

    Full Text Available Manifestations of the so-called structure induced nonlinearity are considered for the case of a granular medium, the latter being a generally accepted model of nonconsolidated rocks in seismics. The consideration is carried out using the medium model in the form of the 'ideal' random packing of spherical elastic granules in which the interparticle space can be filled with a fluid. A physical equation of such a medium is derived; the dependencies of nonlinear parameters on the grain material elastic moduli, the fluid compressibility and the initial medium strain are analyzed. The influence of defects in nonideal grain packings (that is, the presence of a fraction of unloaded intergranular contacts upon the nonlinear properties of the medium is investigated. It is shown that the packing nonideality has the stronger effect on higher-order nonlinear properties. It is demonstrated that the nonlinear parameters may be used in exploration seismology as a much more sensitive and informative characteristic compared with conventionally used linear moduli.

  8. Vibration-induced white finger among selected underground rock drillers in British Columbia.

    Science.gov (United States)

    Brubaker, R L; Mackenzie, C J; Hutton, S G

    1986-08-01

    Ninety-five rock drillers who used pneumatic hand-held drills were interviewed and tested. Thirty-seven were excluded because of factors predisposing to the appearance of white fingers other than exposure to industrial hand-drill vibration. Forty-five percent of the remaining 58 drillers suffered from periodic attacks of Raynaud's phenomenon. Symptoms were present in 25% of the drillers exposed for 1-5 years and in 80% of those exposed for greater than or equal to 16 years. Nine percent of the cases were classified as severe. The median latency for the onset of the blanching symptoms was 7.5 years. The prevalence of Raynaud's phenomenon was 4% among a reference group of 56 miners not exposed to hand vibration and corrected for possible predisposing factors. Objective evidence indicated delayed finger rewarming after a combination of digital ischemia and cooling in 75% of the drillers with blanching symptoms and 18% of the referents without symptoms. There was evidence of an increased frequency of vibration-induced white finger among current cigarette smokers. Weighted 4-h equivalent acceleration levels measured from the handles of 26 jack-leg and 13 stoper drills from the same mines as the miners ranged from 15 to 32 m/s2. These levels exceed recommended guidelines of the International Organization for Standardization.

  9. Measurement of dynamic magnetization induced by a pulsed field: Proposal for a new rock magnetism method

    Science.gov (United States)

    Kodama, Kazuto

    2015-02-01

    This study proposes a new method for measuring transient magnetization of natural samples induced by a pulsed field with duration of 11 ms using a pulse magnetizer. An experimental system was constructed, consisting of a pair of differential sensing coils connected with a high-speed digital oscilloscope for data acquisition. The data were transferred to a computer to obtain an initial magnetization curve and a descending branch of a hysteresis loop in a rapidly changing positive field. This system was tested with synthetic samples (permalloy ribbon, aluminum plate, and nickel powder) as well as two volcanic rock samples. Results from the synthetic samples showed considerable differences from those measured by a quasi-static method using a vibrating sample magnetometer (VSM). These differences were principally due to the time-dependent magnetic properties or to electromagnetic effects, such as magnetic viscosity, eddy current loss, or magnetic relaxation. Results from the natural samples showed that the transient magnetization-field curves were largely comparable to the corresponding portions of the hysteresis loops. However, the relative magnetization (scaled to the saturation magnetization) at the end of a pulse was greater than that measured by a VSM. This discrepancy, together with the occurrence of rapid exponential decay after a pulse, indicates magnetic relaxations that could be interpreted in terms of domain wall displacement. These results suggest that with further developments, the proposed technique can become a useful tool for characterizing magnetic particles contained in a variety of natural materials.

  10. Measurement of dynamic magnetization induced by a pulsed field: Proposal for a new rock magnetism method

    Directory of Open Access Journals (Sweden)

    Kazuto eKodama

    2015-02-01

    Full Text Available This study proposes a new method for measuring transient magnetization of natural samples induced by a pulsed field with duration of 11 ms using a pulse magnetizer. An experimental system was constructed, consisting of a pair of differential sensing coils connected with a high-speed digital oscilloscope for data acquisition. The data were transferred to a computer to obtain an initial magnetization curve and a descending branch of a hysteresis loop in a rapidly changing positive field. This system was tested with synthetic samples (permalloy ribbon, aluminum plate, and nickel powder as well as two volcanic rock samples. Results from the synthetic samples showed considerable differences from those measured by a quasi-static method using a vibrating sample magnetometer (VSM. These differences were principally due to the time-dependent magnetic properties or to electromagnetic effects, such as magnetic viscosity, eddy current loss, or magnetic relaxation. Results from the natural samples showed that the transient magnetization–field curves were largely comparable to the corresponding portions of the hysteresis loops. However, the relative magnetization (scaled to the saturation magnetization at the end of a pulse was greater than that measured by a VSM. This discrepancy, together with the occurrence of rapid exponential decay after a pulse, indicates magnetic relaxations that could be interpreted in terms of domain wall displacement. These results suggest that with further developments, the proposed technique can become a useful tool for characterizing magnetic particles contained in a variety of natural materials.

  11. Analysis of gold in rock samples using laser-induced breakdown spectroscopy: Matrix and heterogeneity effects

    Science.gov (United States)

    Rifai, Kheireddine; Laflamme, Marcel; Constantin, Marc; Vidal, François; Sabsabi, Mohamad; Blouin, Alain; Bouchard, Paul; Fytas, Konstantinos; Castello, Maryline; Kamwa, Blandine Nguegang

    2017-08-01

    We used the laser-induced breakdown spectroscopy (LIBS) technique to determine the concentration of gold in rock samples. 44 reference materials (mostly compressed fine powders) of various chemical compositions, with a quasi-homogeneous concentration of gold varying from 0 to 1000 ppm, were used to establish the calibration curve for the Au I 267.59 nm line. A chemometric study based on the principal component analysis (PCA) showed that 83% of the LIBS spectra variations are attributable to the presence of iron in the samples. Two distinct branches were obtained in the calibration curve: one for Si-rich samples ( 13% of iron) with limits of detection of 0.8 ppm and 1.5 ppm, respectively. Different normalization schemes of the gold signal were tested in order to reduce the matrix effects. The LIBS analysis was performed on various mineral samples of practical interest, namely two Si-rich uncompressed ore powders, fine and granular, and three bulk drill cores. The fluctuations in the gold concentration measurements appear to be about two times greater in the granular powder (5-10%) than in the fine one (2-5%). A detailed mapping of the gold concentration on a solid drill core was also performed, revealing multiscale heterogeneity of the gold distribution on the surface of the sample.

  12. Prediction of the area affected by earthquake-induced landsliding based on seismological parameters

    Science.gov (United States)

    Marc, Odin; Meunier, Patrick; Hovius, Niels

    2017-07-01

    We present an analytical, seismologically consistent expression for the surface area of the region within which most landslides triggered by an earthquake are located (landslide distribution area). This expression is based on scaling laws relating seismic moment, source depth, and focal mechanism with ground shaking and fault rupture length and assumes a globally constant threshold of acceleration for onset of systematic mass wasting. The seismological assumptions are identical to those recently used to propose a seismologically consistent expression for the total volume and area of landslides triggered by an earthquake. To test the accuracy of the model we gathered geophysical information and estimates of the landslide distribution area for 83 earthquakes. To reduce uncertainties and inconsistencies in the estimation of the landslide distribution area, we propose an objective definition based on the shortest distance from the seismic wave emission line containing 95 % of the total landslide area. Without any empirical calibration the model explains 56 % of the variance in our dataset, and predicts 35 to 49 out of 83 cases within a factor of 2, depending on how we account for uncertainties on the seismic source depth. For most cases with comprehensive landslide inventories we show that our prediction compares well with the smallest region around the fault containing 95 % of the total landslide area. Aspects ignored by the model that could explain the residuals include local variations of the threshold of acceleration and processes modulating the surface ground shaking, such as the distribution of seismic energy release on the fault plane, the dynamic stress drop, and rupture directivity. Nevertheless, its simplicity and first-order accuracy suggest that the model can yield plausible and useful estimates of the landslide distribution area in near-real time, with earthquake parameters issued by standard detection routines.

  13. The role of local soil-induced amplification in the 27 July 1980 northeastern Kentucky earthquake

    Science.gov (United States)

    Woolery, E.W.; Lin, T.-L.; Wang, Z.; Shi, B.

    2008-01-01

    Amplification of earthquake ground motions by near-surface soil deposits was believed to have occurred in Maysville, Kentucky, U.S.A. during the northeast Kentucky (Sharpsburg) earthquake (mb,Lg 5.3) of July 27, 1980. The city of Maysville, founded on approximately 30 m of Late Quaternary Ohio River flood plain alluvium, was 52 km from the epicenter, but experienced equivalent or higher Modified Mercalli Intensity (MMI) VII, compared with the epicentral area of the earthquake (i.e., MMI VI-VII). In this study, dynamic soil properties were obtained at 10 sites in Maysville using seismic P-wave and S-wave (SH-mode) refraction and reflection methods. Synthetically generated composite time histories and limited geotechnical information, along with the measured dynamic properties, were used to perform one-dimensional linear-equivalent amplification analyses. The results indicated the soils generated ground-motion amplification factors between 3.0 and 6.0 and at a frequency range between 2.0 and 5.0 Hz (0.2 to 0.5 s). The building damage in Maysville from the Sharpsburg earthquake was predominantly found in one- to three-story masonry structures. The estimated fundamental period for one- to three-story masonry buildings is approximately 0.11 to 0.26 s (3.8 to 9 Hz). These correlations suggest the elevated ground motion intensity in Maysville can be accounted for by near-surface soil-amplification effects and resonance of the ground motion by the buildings (i.e., double resonance).

  14. Salidroside ameliorates arthritis-induced brain cognition deficits by regulating Rho/ROCK/NF-κB pathway.

    Science.gov (United States)

    Zhu, Lingpeng; Chen, Tong; Chang, Xiayun; Zhou, Rui; Luo, Fen; Liu, Jingyan; Zhang, Kai; Wang, Yue; Yang, Ying; Long, Hongyan; Liu, Yu; Yan, Tianhua; Ma, Chunhua

    2016-04-01

    The prevalence of cognitive impairment in rheumatoid arthritis (RA) patients was increasingly serious nowadays. The purpose of the current study was to explore whether salidroside (Sal) could alleviate arthritis-induced cognition deficits and examine the relationship between the impairment and Rho/ROCK/NF-κB pathway. Collagen-induced arthritis (CIA) was established by the injection of chicken type II collagen (CII), complete Freund's adjuvant (CFA) and incomplete Freund's adjuvant (IFA). Arthritic lesions of CIA rats were assessed by arthritis index score, swelling of paws and histological analysis. Cognitive deficits symptoms of CIA rats were monitored through Morris water maze test. The contents of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in hippocampus and serum were significantly reduced with salidroside (20 mg/kg, 40 mg/kg) treatment compared with those in the CIA group. In parallel, we demonstrated that the expressions of RhoA, ROCK1, ROCK2, p-NF-κBp65, p-IκBα, p-IKKα and p-IKKβ were enhanced accompanying the investigation arthritis-induced cognition deficits, which were remarkably down-regulated by salidroside and confirmed by the results obtained from western blot and immunohistochemistry. LC-MS/MS results ascertained that Sal could enter into the blood and brain tissues to exhibit the protective effect on arthritis-induced cognitive dysfunction. Therefore, it was assumed that Sal might be a potential therapeutic candidate to treat arthritis-induced brain cognition deficits through the regulation of Rho/ROCK/NF-κB signaling.

  15. Recurring Large-Scale, Earthquake-Induced Landslides in Port Valdez, Alaska

    Science.gov (United States)

    Lee, H. J.; Ryan, H. F.; Alexander, C.; Haeussler, P.

    2008-12-01

    Recent multibeam mapping, sub-bottom profiling, and coring in Port Valdez, Alaska have disclosed massive debris flow deposits and large blocks displaced during the 1964 M9.2 Alaska earthquake. These failures led to some of the highest tsunami wave runups ever documented (~50 m). Landslide volumes have been calculated using available bathymetry from before and after the earthquake, as well as from calculations based on observed acoustic facies in the sub-bottom profiles. The volumes based on the sub-bottom data are significantly greater than those calculated from bathymetric change, indicating that much of the debris in the mass wasting deposits consists of material remobilized from the seafloor during landslide motion. Although the total volume of the debris flow deposits exceeds the volume of the large displaced blocks, the highest tsunami runups were adjacent to the blocks. This indicates that the displacement of large, intact blocks may be a more efficient tsunami generator than large-scale sediment flows. Mini-sparker data reveal up to 5 additional debris lobes below the 1964 landslide deposits. These lobes are separated by coherent, layered reflectors, interpreted as normal fjord sedimentation, unaffected by mass wasting processes. Assuming that the first debris flow deposit imaged beneath the 1964 was created by the penultimate earthquake on the Alaskan megathrust (dated at 913-808 yrs BP by Carver and Plafker), we calculate a sediment accumulation rate of about 2 cm/yr for the inter-lobe deposits. This rate is compatible with that determined for post-1964 deposits using 137Cs peaks in sediment cores from Port Valdez. Deposits attributed to submarine failures triggered by the 1964 and penultimate earthquake events have a similar distribution across the entire fjord. However, earlier events are not present in western Port Valdez, suggesting that failures in this area, which in 1964 involved a large moraine at the toe of Shoup Glacier, did not occur until more

  16. Static stress drop of the largest recorded M 4.6 hydraulic fracturing induced earthquake and its aftershock pattern in the northern Montney Play, British Columbia, Canada

    Science.gov (United States)

    Wang, B.; Harrington, R. M.; Liu, Y.; Kao, H.

    2016-12-01

    The largest suspected fracking-induced earthquake to date occurred near Fort St. John, British Columbia on August 17, 2015, with a reported magnitude of Mw 4.6. Here we estimate the static stress released by the mainshock and the five cataloged aftershocks using new data from eight broadband seismometers installed approximately 50km from the hypocenter of the mainshock, at distances much closer than the Natural Resources Canada regional seismic stations. The estimated cross-correlation coefficient among the 5 cataloged earthquakes is 0.35 or greater. We will present seismic moment (M0) and spectral corner frequency (fc) values estimated using both individual earthquake spectra and spectral ratios to correct for travel-path attenuation and site effects. Static stress drop and scaled energy value calculations based on the estimated moment and corner frequency values will be presented, as well as focal mechanisms for the largest events with adequate station coverage. We will also use a multi-station matched-filter approach to detect additional uncataloged earthquakes on continuous waveforms for a period of two months after the mainshock. Using the results of the matched-filter approach, we will present the aftershock magnitude distribution and locations. The results of our detection and location calculations will be compared to reported fracking parameters, such as fluid injection pressure and duration, to determine their correlation with the spatial and temporal distribution of aftershocks. The objective of this study is to relate operational parameters to earthquake occurrence in order to help to develop procedures to understand the mechanisms responsible for fracking induced earthquakes, their relation to the maximum induced magnitude, and to reduce potential hazards of anthropogenically induced seismic activity.

  17. Exposure to music and noise-induced hearing loss (NIHL) among professional pop/rock/jazz musicians

    OpenAIRE

    Halevi-Katz, Dana N.; Erez Yaakobi; Hanna Putter-Katz

    2015-01-01

    Noise-induced hearing loss (NIHL) has been extensively studied in industrial work environments. With the advent of new technologies, loud music has been increasingly affecting listeners outside of the industrial setting. Most research on the effects of music and hearing loss has focused on classical musicians. The purpose of the current study was to examine the relationship between the amount of experience a professional pop/rock/jazz musician has and objective and subjective variables of the...

  18. Landslides and Earthquake Lakes from the Wenchuan, China Earthquake - Can it Happen in the U.S.?

    Science.gov (United States)

    Stenner, H.; Cydzik, K.; Hamilton, D.; Cattarossi, A.; Mathieson, E.

    2008-12-01

    The May 12, 2008 M7.9 Wenchuan, China earthquake destroyed five million homes and schools, causing over 87,650 deaths. Landslides, a secondary effect of the shaking, caused much of the devastation. Debris flows buried homes, rock falls crushed cars, and landslides dammed rivers. Blocked roads greatly impeded emergency access, delaying response. Our August 2008 field experience in the affected area reminded us that the western United States faces serious risks posed by earthquake-induced landslides. The topography of the western U.S. is less extreme than that near Wenchuan, but earthquakes may still cause devastating landslides, damming rivers and blocking access to affected areas. After the Wenchuan earthquake, lakes rapidly rose behind landslide dams, threatening millions of lives. One landslide above Beichuan City created Tangjiashan Lake, a massive body of water upstream of Mianyang, an area with 5.2 million people, 30,000 of whom were killed in the quake. Potential failure of the landslide dam put thousands more people at risk from catastrophic flooding. In 1959, the M7.4 Hebgen Lake earthquake in Montana caused a large landslide, which killed 19 people and dammed the Madison River. The Army Corps excavated sluices to keep the dam from failing catastrophically. The Hebgen Lake earthquake ultimately caused 28 deaths, mostly from landslides, but the affected region was sparsely populated. Slopes prone to strong earthquake shaking and landslides in California, Washington, and Oregon have much larger populations at risk. Landslide hazards continue after the earthquake due to the effect strong shaking has on hillslopes, particularly when subjected to subsequent rain. These hazards must be taken into account. Once a landslide blocks a river, rapid and thoughtful action is needed. The Chinese government quickly and safely mitigated landslide dams that posed the greatest risk to people downstream. It took expert geotechnical advice, the speed and resources of the army

  19. Model parameter estimation bias induced by earthquake magnitude cut-off

    Science.gov (United States)

    Harte, D. S.

    2016-02-01

    We evaluate the bias in parameter estimates of the ETAS model. We show that when a simulated catalogue is magnitude-truncated there is considerable bias, whereas when it is not truncated there is no discernible bias. We also discuss two further implied assumptions in the ETAS and other self-exciting models. First, that the triggering boundary magnitude is equivalent to the catalogue completeness magnitude. Secondly, the assumption in the Gutenberg-Richter relationship that numbers of events increase exponentially as magnitude decreases. These two assumptions are confounded with the magnitude truncation effect. We discuss the effect of these problems on analyses of real earthquake catalogues.

  20. Hadal disturbance in the Japan Trench induced by the 2011 Tohoku-Oki earthquake

    DEFF Research Database (Denmark)

    Oguri, K.; Kawamura, K.; Sakaguchi, A.

    2013-01-01

    In situ video observations and sediment core samplings were performed at two hadal sites in the Japan Trench on July, 2011, four months after the Tohoku-Oki earthquake. Video recordings documented dense nepheloid layers extending similar to 30-50 m above the sea bed. At the trench axis, benthic...... macrofauna was absent and dead organisms along with turbid downslope current were observed. The top 31 cm of sediment in the trench axis revealed three recent depositions events characterized by elevated Cs-137 levels and alternating sediment densities. At 4.9 km seaward from the trench axis, little...

  1. On the origin of exponential growth in induced earthquakes in Groningen

    CERN Document Server

    van Putten, Maurice H P M; van Putten, Michael J A M

    2016-01-01

    The Groningen gas field shows exponential growth in earthquakes event counts around a magnitude M1 with a doubling time of 6-9 years since 2001. This behavior is identified with dimensionless curvature in land subsidence, which has been evolving at a constant rate over the last few decades {essentially uncorrelated to gas production.} We demonstrate our mechanism by a tabletop crack formation experiment. The observed skewed distribution of event magnitudes is matched by that of maxima of event clusters with a normal distribution. It predicts about one event $<$\\,M5 per day in 2025, pointing to increasing stress to human living conditions.

  2. MINING INDUCED INFLUENCE ON THE ROADWAYS IN WEAK SURROUNDING ROCK AND ITS CONTROLLING MEASURES

    Institute of Scientific and Technical Information of China (English)

    陆士良; 王悦汉

    1991-01-01

    The application of destressing method can change the distribution patterns of the stress field in the weak rock surrounding openings, locate the openings in the zone of low stress level, thus improve their loading and maintaining conditions. Such method is considered as a new way of opening maintenance in weak rock and has caused extensive interests in mining industry both at home and abroad. The results of theoretic research and lab experiments of utilizing topdestresslng trough to maintain the opening affected by mining activities in weak rock, as well as its practical application in a coal mine are introduced in this paper. The research results indicate that the deformation and floor heaving of the opening in weak rock can be effectively controlled, and long-term stability of the opening can be realized by applying destressing method as long as the destressing plan and concerned parameters are carefully determined.

  3. Experimental Investigation on Limit Cycle Wing Rock Effect on Wing Body Configuration Induced by Forebody Vortices

    National Research Council Canada - National Science Library

    Rong, Zhen; Deng, Xueying; Ma, Baofeng; Wang, Bing

    2016-01-01

    ...° swept wing configuration undergoing a limit cycle oscillation using a synchronous measurement and control technique of wing rock/particle image velocimetry/dynamic pressure associated with the time...

  4. Rock avalanches: significance and progress (Invited)

    Science.gov (United States)

    Davies, T. R.

    2013-12-01

    1. The probability distribution of landslide volumes follows a power-law indicating that large rock avalanches dominate the terrestrial sediment supply from mountains, and that their source area morphologies dominate mountain topography. 2. Large rock slope failures (~ 106 m3 or greater) often mobilise into rock avalanches, which can travel extraordinarily long distances with devastating effect. This hypermobility has been the subject of many investigations; we have demonstrated that it can be explained quantitatively and accurately by considering the energetics of the intense rock fragmentation that always occurs during motion of a large rock mass. 3. Study of rock avalanche debris psd shows that the energy used in creating new rock surface area during fragmentation is not lost to surface energy, but is recycled generating a high-frequency elastic energy field that reduces the frictional resistance to motion during runout. 4. Rock avalanches that deposit on glaciers can eventually form large terminal moraines that have no connection with any climatic event; unless these are identified as rock-avalanche-influenced they can confuse palaeoclimatic inferences drawn from moraine ages. Rock-avalanche-derived fines, however, can be identified in moraine debris up to ten thousand years old by the characteristic micron-scale agglomerates that form during intense fragmentation, and which are absent from purely climatically-induced moraines; there is thus a strong case for re-examining existing palaeoclimatic databases to eliminate potentially rock-avalanche-influenced moraine ages. 5. Rock avalanches (especially coseismic ones) are a serious hazard, being very destructive in their own right; they also block river valleys, forming landslide dams and potentially devastating dambreak floods, and subsequent severe decade-scale aggradation of downstream fans and floodplains. Rock avalanches falling into lakes or fiords can cause catastrophic tsunami that pose a serious risk to

  5. Rock-type control on erosion-induced uplift, eastern Swiss Alps

    Science.gov (United States)

    Korup, Oliver; Schlunegger, Fritz

    2009-02-01

    There is growing evidence that Quaternary rock uplift in parts of the European Alps is a consequence of climate- and erosion-driven isostatic rebound. Contemporary rates of rock uplift U in the Swiss Alps show two distinctive dome-like peak regions that attain ~ 1.6 mm yr - 1 . We focus on the Alpenrhein catchment and its surroundings, where one of these peak regions spatially coincides with widely exposed Cretaceous Bündner schist and lower Tertiary flysch. Field assessments and analyses of hillslope gradient distributions quantitatively demonstrate the low rock-mass strength and high erodibility of these rocks. This is reflected in mean postglacial catchment erosion rates D ~ 4 mm yr - 1 , as opposed to 0.7 mm yr - 1 in more resistant crystalline rocks. Though largely inferred from landslide- and debris-flow prone tributary catchments export, from the region. We further find that the steepness of bedrock rivers, the density of large landslides, and D correlate with the highest values of U. Our observations highlight the possibility that erosion of mechanically weak Bündner schist and flysch enhanced by large landslides may have contributed to regional crustal unloading, and concomitant rock uplift. Irrespective of whether this is betraying a coupling between long-term uplift and erosion modulated by rock type, our findings indicate that long-term (10 3 to 10 4 yr) geomorphic signals contained in bedrock-river steepness, spatial density of large landslides, and postglacial erosion rates strikingly correlate with regional gradients of historic (10 1 yr) rock uplift rates.

  6. ROCK2 associates with lectin-like oxidized LDL receptor-1 and mediates oxidized LDL-induced IL-8 production.

    Science.gov (United States)

    Mattaliano, Mark D; Wooters, Joe; Shih, Heather H; Paulsen, Janet E

    2010-05-01

    Oxidatively modified low-density lipoprotein (OxLDL) is a contributing factor of endothelial dysfunction, an early cellular event during atherogenesis. In endothelial cells, OxLDL has been shown to stimulate proinflammatory responses, increase lipid accumulation, and induce the expression of adhesion and extracellular matrix degrading molecules. The primary receptor for OxLDL on endothelial cells has been identified as a member of the scavenger receptor family called lectin-like OxLDL receptor-1 (LOX-1). A number of studies on LOX-1 have implicated its role in multiple cardiovascular diseases including atherosclerosis. To better understand the molecular mechanisms underlying the role of LOX-1 in endothelial cells, we identified interacting proteins in an affinity-purified LOX-1 receptor complex from human aortic endothelial HAECT cells by mass spectrometry. Two molecules involved in Rho signaling pathway, ARHGEF1 and ROCK2, were identified, and their associations with LOX-1 were confirmed in reciprocal immunoprecipitation studies. Particularly, ROCK2 was found to dynamically associate with LOX-1 in the presence of OxLDL. In addition, OxLDL treatment stimulated ROCK2 catalytic activity, and ROCK2 inhibition attenuated NF-kappaB activation and IL-8 production resulting from OxLDL activation of LOX-1. In summary, a functional proteomics approach has enabled us to identify novel LOX-1 interactors that potentially contribute to the cellular and signaling functions of LOX-1.

  7. Comparative study on earthquake and ground based transmitter induced radiation belt electron precipitation at middle latitudes

    Directory of Open Access Journals (Sweden)

    N. F. Sidiropoulos

    2011-07-01

    Full Text Available We examined (peak-to-background flux ratio p/b > 20 energetic electron bursts in the presence of VLF activity, as observed from the DEMETER satellite at low altitudes (~700 km. Our statistical analysis of measurements during two 6-month periods suggests that: (a the powerful transmitter NWC causes the strongest effects on the inner radiation belts in comparison with other ground-based VLF transmitters, (b the NWC transmitter was responsible for only ~1.5 % of total electron bursts examined during the 6-month period (1 July 2008 to 31 December 2008, (c VLF transmitter-related electron bursts are accompanied by the presence of a narrow band emission centered at the radiating frequency emission, whereas the earthquake-related electron bursts are accompanied by the presence of broadband emissions from a few kHz to >20 KHz, (d daytime events are less preferable than nighttime events, but this asymmetry was found to be less evident when the powerful transmitter NWC was turned off and (d seismic activity most probably dominated the electromagnetic interactions producing the electron precipitation at middle latitudes. The results of this study support the proposal that the detection of radiation belt electron precipitation, besides other kinds of studies, is a useful tool for earthquake prediction research.

  8. Integrating Machine Learning into a Crowdsourced Model for Earthquake-Induced Damage Assessment

    Science.gov (United States)

    Rebbapragada, Umaa; Oommen, Thomas

    2011-01-01

    On January 12th, 2010, a catastrophic 7.0M earthquake devastated the country of Haiti. In the aftermath of an earthquake, it is important to rapidly assess damaged areas in order to mobilize the appropriate resources. The Haiti damage assessment effort introduced a promising model that uses crowdsourcing to map damaged areas in freely available remotely-sensed data. This paper proposes the application of machine learning methods to improve this model. Specifically, we apply work on learning from multiple, imperfect experts to the assessment of volunteer reliability, and propose the use of image segmentation to automate the detection of damaged areas. We wrap both tasks in an active learning framework in order to shift volunteer effort from mapping a full catalog of images to the generation of high-quality training data. We hypothesize that the integration of machine learning into this model improves its reliability, maintains the speed of damage assessment, and allows the model to scale to higher data volumes.

  9. Diking-induced moderate-magnitude earthquakes on a youthful rift border fault: The 2002 Nyiragongo-Kalehe sequence, D.R. Congo

    Science.gov (United States)

    Wauthier, C.; Smets, B.; Keir, D.

    2015-12-01

    On 24 October 2002, Mw 6.2 earthquake occurred in the central part of the Lake Kivu basin, Western Branch of the East African Rift. This is the largest event recorded in the Lake Kivu area since 1900. An integrated analysis of radar interferometry (InSAR), seismic and geological data, demonstrates that the earthquake occurred due to normal-slip motion on a major preexisting east-dipping rift border fault. A Coulomb stress analysis suggests that diking events, such as the January 2002 dike intrusion, could promote faulting on the western border faults of the rift in the central part of Lake Kivu. We thus interpret that dike-induced stress changes can cause moderate to large-magnitude earthquakes on major border faults during continental rifting. Continental extension processes appear complex in the Lake Kivu basin, requiring the use of a hybrid model of strain accommodation and partitioning in the East African Rift.

  10. Solar-induced weathering of rocks: integrating instrumental and numerical studies

    Science.gov (United States)

    Hallet, B.; Eppes, M. C.; Mackenzie-Helnwein, P.; Warren, K.; McFadden, L.; Gillespie, A.; Putkonen, J.; Swami, S.; Shi, J.

    2011-12-01

    The contribution of solar-driven thermal cycling to the progressive breakdown of surface rocks on the Earth and other planets is controversial. We introduce a current study of the physical state in boulders that integrates modern instrumental and numerical approaches to quantify the surface temperature, stresses, strains, and microfracture activity in exposed boulders, and to shed light on the processes underlying this form of mechanical weathering. We are monitoring the surface and environmental conditions of two ~30 cm dia. granite boulders (one in North Carolina, one in New Mexico) in the field for ~1 yr each. Each rock is instrumented with 8 thermocouples, 8 strain gauges, a surface moisture sensor and 6 Acoustic Emission (AE) sensors to monitor microfracture activity continuously. These sensors and a full meteorological station, including soil-moisture probes, are combined into a single, remotely accessible system. AE events can be located to within 2.5 cm. We are able 1) to spatially and temporally correlate microcrack growth (AE events) with the rock surface and environmental conditions experienced by the rock, and 2) to validate modeling results. The modeling work addresses two coupled problems: 1) the time-varying thermal regime of rocks exposed to diurnal variations in solar radiation as dictated by latitude, and time of the year, as well as the surface emissivity and thermal properties of the rock and soil, and size and shape of the rock, and 2) the corresponding time-varying stress and strain fields in the rocks using representative elastic properties and realistic rock shape and orientation. AE events tend to occur shortly after sunset (6-9 pm) in the upper portion of the boulder. Most of the events occur in summer and winter months for the NC boulder. The majority occur in bursts of tens to hundreds over periods of a few minutes, and are often associated with environmental factors other than simple diurnal warming and cooling, such as wind gusts, that

  11. GSK-3Beta-Dependent Activation of GEF-H1/ROCK Signaling Promotes LPS-Induced Lung Vascular Endothelial Barrier Dysfunction and Acute Lung Injury.

    Science.gov (United States)

    Yi, Lei; Huang, Xiaoqin; Guo, Feng; Zhou, Zengding; Chang, Mengling; Huan, Jingning

    2017-01-01

    The bacterial endotoxin or lipopolysaccharide (LPS) leads to the extensive vascular endothelial cells (EC) injury under septic conditions. Guanine nucleotide exchange factor-H1 (GEF-H1)/ROCK signaling not only involved in LPS-induced overexpression of pro-inflammatory mediator in ECs but also implicated in LPS-induced endothelial hyper-permeability. However, the mechanisms behind LPS-induced GEF-H1/ROCK signaling activation in the progress of EC injury remain incompletely understood. GEF-H1 localized on microtubules (MT) and is suppressed in its MT-bound state. MT disassembly promotes GEF-H1 release from MT and stimulates downstream ROCK-specific GEF activity. Since glycogen synthase kinase (GSK-3beta) participates in regulating MT dynamics under pathologic conditions, we examined the pivotal roles for GSK-3beta in modulating LPS-induced activation of GEF-H1/ROCK, increase of vascular endothelial permeability and severity of acute lung injury (ALI). In this study, we found that LPS induced human pulmonary endothelial cell (HPMEC) monolayers disruption accompanied by increase in GSK-3beta activity, activation of GEF-H1/ROCK signaling and decrease in beta-catenin and ZO-1 expression. Inhibition of GSK-3beta reduced HPMEC monolayers hyper-permeability and GEF-H1/ROCK activity in response to LPS. GSK-3beta/GEF-H1/ROCK signaling is implicated in regulating the expression of beta-catenin and ZO-1. In vivo, GSK-3beta inhibition attenuated LPS-induced activation of GEF-H1/ROCK pathway, lung edema and subsequent ALI. These findings present a new mechanism of GSK-3beta-dependent exacerbation of lung micro-vascular hyper-permeability and escalation of ALI via activation of GEF-H1/ROCK signaling and disruption of intracellular junctional proteins under septic condition.

  12. Exposure to music and noise-induced hearing loss (NIHL among professional pop/rock/jazz musicians

    Directory of Open Access Journals (Sweden)

    Dana N Halevi-Katz

    2015-01-01

    Full Text Available Noise-induced hearing loss (NIHL has been extensively studied in industrial work environments. With the advent of new technologies, loud music has been increasingly affecting listeners outside of the industrial setting. Most research on the effects of music and hearing loss has focused on classical musicians. The purpose of the current study was to examine the relationship between the amount of experience a professional pop/rock/jazz musician has and objective and subjective variables of the musician′s hearing loss. This study also examined professional pop/rock/jazz musicians′ use of hearing protection devices in relation to the extent of their exposure to amplified music. Forty-four pop/rock/jazz musicians were interviewed using the Pop/Rock/Jazz Musician′s Questionnaire (PRJMQ in order to obtain self-reported symptoms of tinnitus and hyperacusis. Forty-two of the subjects were also tested for air-conduction hearing thresholds in the frequency range of 1-8 kHz. Results show that the extent of professional pop/rock/jazz musicians′ exposure to amplified music was related to both objective and subjective variables of hearing loss: Greater musical experience was positively linked to higher hearing thresholds in the frequency range of 3-6 kHz and to the subjective symptom of tinnitus. Weekly hours playing were found to have a greater effect on hearing loss in comparison to years playing. Use of hearing protection was not linked to the extent of exposure to amplified music. It is recommended that further research be conducted with a larger sample, in order to gain a greater understanding of the detrimental effects of hours playing versus years playing.

  13. Exposure to music and noise-induced hearing loss (NIHL) among professional pop/rock/jazz musicians.

    Science.gov (United States)

    Halevi-Katz, Dana N; Yaakobi, Erez; Putter-Katz, Hanna

    2015-01-01

    Noise-induced hearing loss (NIHL) has been extensively studied in industrial work environments. With the advent of new technologies, loud music has been increasingly affecting listeners outside of the industrial setting. Most research on the effects of music and hearing loss has focused on classical musicians. The purpose of the current study was to examine the relationship between the amount of experience a professional pop/rock/jazz musician has and objective and subjective variables of the musician's hearing loss. This study also examined professional pop/rock/jazz musicians' use of hearing protection devices in relation to the extent of their exposure to amplified music. Forty-four pop/rock/jazz musicians were interviewed using the Pop/Rock/Jazz Musician's Questionnaire (PRJMQ) in order to obtain self-reported symptoms of tinnitus and hyperacusis. Forty-two of the subjects were also tested for air-conduction hearing thresholds in the frequency range of 1-8 kHz. Results show that the extent of professional pop/rock/jazz musicians' exposure to amplified music was related to both objective and subjective variables of hearing loss: Greater musical experience was positively linked to higher hearing thresholds in the frequency range of 3-6 kHz and to the subjective symptom of tinnitus. Weekly hours playing were found to have a greater effect on hearing loss in comparison to years playing. Use of hearing protection was not linked to the extent of exposure to amplified music. It is recommended that further research be conducted with a larger sample, in order to gain a greater understanding of the detrimental effects of hours playing versus years playing.

  14. Nowcasting Earthquakes

    Science.gov (United States)

    Rundle, J. B.; Donnellan, A.; Grant Ludwig, L.; Turcotte, D. L.; Luginbuhl, M.; Gail, G.

    2016-12-01

    Nowcasting is a term originating from economics and finance. It refers to the process of determining the uncertain state of the economy or markets at the current time by indirect means. We apply this idea to seismically active regions, where the goal is to determine the current state of the fault system, and its current level of progress through the earthquake cycle. In our implementation of this idea, we use the global catalog of earthquakes, using "small" earthquakes to determine the level of hazard from "large" earthquakes in the region. Our method does not involve any model other than the idea of an earthquake cycle. Rather, we define a specific region and a specific large earthquake magnitude of interest, ensuring that we have enough data to span at least 20 or more large earthquake cycles in the region. We then compute the earthquake potential score (EPS) which is defined as the cumulative probability distribution P(nearthquakes in the region. From the count of small earthquakes since the last large earthquake, we determine the value of EPS = P(nearthquake cycle in the defined region at the current time.

  15. Earthquake Facts

    Science.gov (United States)

    Jump to Navigation Earthquake Facts The largest recorded earthquake in the United States was a magnitude 9.2 that struck Prince William Sound, ... we know, there is no such thing as "earthquake weather" . Statistically, there is an equal distribution of ...

  16. Nowcasting earthquakes

    Science.gov (United States)

    Rundle, J. B.; Turcotte, D. L.; Donnellan, A.; Grant Ludwig, L.; Luginbuhl, M.; Gong, G.

    2016-11-01

    Nowcasting is a term originating from economics and finance. It refers to the process of determining the uncertain state of the economy or markets at the current time by indirect means. We apply this idea to seismically active regions, where the goal is to determine the current state of the fault system and its current level of progress through the earthquake cycle. In our implementation of this idea, we use the global catalog of earthquakes, using "small" earthquakes to determine the level of hazard from "large" earthquakes in the region. Our method does not involve any model other than the idea of an earthquake cycle. Rather, we define a specific region and a specific large earthquake magnitude of interest, ensuring that we have enough data to span at least 20 or more large earthquake cycles in the region. We then compute the earthquake potential score (EPS) which is defined as the cumulative probability distribution P(n < n(t)) for the current count n(t) for the small earthquakes in the region. From the count of small earthquakes since the last large earthquake, we determine the value of EPS = P(n < n(t)). EPS is therefore the current level of hazard and assigns a number between 0% and 100% to every region so defined, thus providing a unique measure. Physically, the EPS corresponds to an estimate of the level of progress through the earthquake cycle in the defined region at the current time.

  17. ROCK2 regulates bFGF-induced proliferation of SH-SY5Y cells through GSK-3β and β-catenin pathway.

    Science.gov (United States)

    Boku, Shuken; Nakagawa, Shin; Toda, Hiroyuki; Kato, Akiko; Takamura, Naoki; Omiya, Yuki; Inoue, Takeshi; Koyama, Tsukasa

    2013-01-25

    Increased neurogenesis by promoting proliferation of neural precursor cells in the adult dentate gyrus might be beneficial for the treatment of psychiatric disorders. Results demonstrate that bFGF is necessary for the proliferation of neural precursor cells and that the glycogen synthase kinase-3β (GSK-3β) and β-catenin pathway plays a role in it. However, the detailed mechanism of proliferation of neural precursor cells remains unclear. To elucidate that mechanism, we investigated the role of Rho-associated coiled-coil kinase (ROCK) in bFGF-induced proliferation using SH-SY5Y cells as a model of neural precursor-like cells. Y27632, a specific inhibitor of ROCK, decreased bFGF-induced proliferation. Lithium (Li), an inhibitor of GSK-3β, recovered Y27632-decreased proliferation and quercetin (Que), an inhibitor of β-catenin pathway, reversed the recovery effect of Li. Both nuclear β-catenin and cyclin D1 expression were altered by bFGF, Y27632, Li, and Que in parallel with the case of proliferation. Furthermore, bFGF inactivated GSK-3β through increasing the phosphorylation of Ser(9) on GSK-3β, which is reversed by Y27632 through increased phosphorylation of Tyr(216) on GSK-3β. ROCK has two subtypes: ROCK1 and ROCK2. Investigation with siRNA for ROCKs showed that ROCK2 is involved in bFGF-induced proliferation, but not ROCK1. These results suggest that ROCK2 might mediate bFGF-induced proliferation of SH-SY5Y cells through GSK-3β and β-catenin pathway. Further investigation of detailed mechanisms regulating the ROCK2/GSK-3β/β-catenin pathway might engender the development of new therapeutic targets of psychiatric disorders.

  18. Pressure oscillation induced by composite fluid flow - Physical picture generating low frequency earthquake -

    Science.gov (United States)

    Takashima, S.; Kurita, K.

    2006-12-01

    Recently low frequency (LF) earthquakes have been found to occur in various geophysical settings. Structural inspection of the source region and analysis of focal mechanism suggest the possible role of fluid in the generation process. The nature of fluid expected in the source region should be characterized by multiphase system such as magma and gas bubble, magma and crystal and aqueous fluid and gas bubble, for example. In this system the physical properties of this composite depends on the mutual volume fraction. The volume fraction is variable depending on the flow situation. We consider the link between the flow situation and the volume fraction is an essential part of the composite flow. Here based on the concept that nature of the composite flow plays a central role in the generation of pressure oscillation, we report a simple laboratory model to demonstrate LF earthquakes. The multiphase system in the source region of the LF earthquakes is modeled here as a composite of viscous fluid and incompressible granular phase. plastic particles made of polystyrene (0.5 mm in diameter) and glycerol solution is packed into a cylindrical case (60 mm in diameter). The packing state of the solid phase is near random closed packing state. The glycerol solution flows into the case from the pressure reservoir and it goes out from exit tube with 60 mm in length and 3 mm in diameter. The pressure is measured using a pressure sensor. The control parameter is fluid pressure (1 atm plus 300 Pa to 1500 Pa) and its viscosity (30 mPas to 100 mPas) in this experiment. When the pressure difference between the case is low, the flow is characterized as a permeable flow. Only the interstitial fluid of the glycerol solution flows out depending on the pressure difference. When the pressure difference is above the critical value, both fluid and particles flow out as a composite flow. In this state the output pressure was observed to oscillate. In the diagram of power spectrum of the

  19. Scenarios Susceptible to Induced Liquefaction Caused by High Magnitude Earthquakes in Santiago de Cuba

    Directory of Open Access Journals (Sweden)

    Liuska Fernández-Diéguez

    2016-05-01

    Full Text Available The objective of this investigation was to define the zoning of soil liquefaction potential for the Guillermón Moncada Popular Council in the municipality of Santiago de Cuba. The engineering and geological conditions and seismic peculiarities favoring a seism to take place were assessed. The safety factor was re-calculated after determining possible maximum intensity values based on seismic magnitudes that can trigger the soil of the investigated area to liquefy. A scheme of the area´s soil susceptibility to liquefaction was obtained. Based on this result, it was concluded that the sectors that are most likely to experience soil liquefaction if an earthquake of magnitudes ranging between 7,75 and 8 occurs are located towards the center-east of the Popular Council with sandy-clayey soils being predominant. This information is very useful for the location and planning of engineering construction works in the area.

  20. Phase Transformations and Earthquakes

    Science.gov (United States)

    Green, H. W.

    2011-12-01

    Phase transformations have been cited as responsible for, or at least involved in, "deep" earthquakes for many decades (although the concept of "deep" has varied). In 1945, PW Bridgman laid out in detail the string of events/conditions that would have to be achieved for a solid/solid transformation to lead to a faulting instability, although he expressed pessimism that the full set of requirements would be simultaneously achieved in nature. Raleigh and Paterson (1965) demonstrated faulting during dehydration of serpentine under stress and suggested dehydration embrittlement as the cause of intermediate depth earthquakes. Griggs and Baker (1969) produced a thermal runaway model of a shear zone under constant stress, culminating in melting, and proposed such a runaway as the origin of deep earthquakes. The discovery of Plate Tectonics in the late 1960s established the conditions (subduction) under which Bridgman's requirements for earthquake runaway in a polymorphic transformation could be possible in nature and Green and Burnley (1989) found that instability during the transformation of metastable olivine to spinel. Recent seismic correlation of intermediate-depth-earthquake hypocenters with predicted conditions of dehydration of antigorite serpentine and discovery of metastable olivine in 4 subduction zones, suggests strongly that dehydration embrittlement and transformation-induced faulting are the underlying mechanisms of intermediate and deep earthquakes, respectively. The results of recent high-speed friction experiments and analysis of natural fault zones suggest that it is likely that similar processes occur commonly during many shallow earthquakes after initiation by frictional failure.

  1. Explore Seismic Velocity Change Associated with the 2010 Kaohsiung Earthquake by Ambient Noise Tomography

    Science.gov (United States)

    Ku, Chin-Shang; Wu, Yih-Min; Huang, Bor-Shouh; Huang, Win-Gee; Liu, Chun-Chi

    2016-04-01

    A ML 6.4 earthquake occurred on 4 March 2010 in Kaohsiung, the southern part of Taiwan, this shallow earthquake is the largest one of that area in the past few years. Some damages occurred on buildings and bridges after the earthquake, obvious surface deformation up to few cm was observed and the transportation including road and train traffic was also affected near the source area. Some studies about monitoring the velocity change induced by the big earthquake were carried out recently, most of studies used cross-correlation of the ambient noise-based method and indicated velocity drop was observed immediately after the big earthquake. However, this method is not able to constrain the depth of velocity change, and need to assume a homogeneous seismic velocity change during the earthquake. In this study, we selected 25 broadband seismic stations in the southern Taiwan and time period is from 2009/03 to 2011/03. Then we explored the velocity change associated with the 2010 Kaohsiung earthquake by applying ambient noise tomography (ANT) method. ANT is a way of using interferometry to image subsurface seismic velocity variations by using surface wave dispersions extracted from the ambient noise cross-correlation of seismic station-pairs, then the 2-D group velocity map with different periods could be extracted. Compare to ambient noise-based cross-correlation analysis, we estimated sensitivity kernel of dispersion curves and converted 2-D group velocity map from "with the period" to "with the depth" to have more constraints on the depth of velocity change. By subtracting shear velocity between "before" and "after" the earthquake, we could explore velocity change associated with the earthquake. Our result shows velocity reduction about 5-10% around the focal depth after the 2010 Kaohsiung earthquake and the post-seismic velocity recovery was observed with time period increasing, which may suggest a healing process of damaged rocks.

  2. The effect of ROCK on TNF-α-induced CXCL8 secretion by intestinal epithelial cell lines is mediated through MKK4 and JNK signaling.

    Science.gov (United States)

    Perey, Aaron C; Weishaar, Isabelle M; McGee, Dennis W

    2015-02-01

    Intestinal epithelial cells (IEC) play a role in mucosal inflammatory responses by producing important chemokines like CXCL8 when stimulated by TNF-α. Previously, we found that IEC cell lines required the Rho-associated kinase, ROCK, for CXCL8 responses after IL-1 stimulation. This study extends these findings by showing that inhibiting ROCK suppressed TNF-α-induced CXCL8 secretion by Caco-2 and DLD1 colonic epithelial cell lines and CXCL8 mRNA levels in Caco-2 cells. RNAi knockdown experiments indicated that the inhibitory effect was mediated by ROCK2, and not ROCK1. Inhibiting ROCK had no effect on TNF-stimulated IκBα phosphorylation and degradation or p38 MAPK phosphorylation indicating that ROCK plays no role in these signaling pathways. However, inhibiting ROCK suppressed TNF-induced phosphorylation of the p54 JNK isoform and phosphorylation of the upstream MKK4 kinase. These results suggest that ROCK is required for CXCL8 responses by TNF-stimulated IEC by affecting intracellular signaling through MKK4 and JNK.

  3. Late Quaternary paleoseismic sedimentary archive from deep central Gulf of Corinth: time distribution of inferred earthquake-induced layers

    Directory of Open Access Journals (Sweden)

    Corina Campos

    2014-02-01

    Full Text Available A sedimentary archive corresponding to the last 17 cal kyr BP has been studied by means of a giant piston core retrieved on board R/V MARION-DUFRESNE in the North Central Gulf of Corinth. Based on previous methodological improvements, grain-size distribution and Magnetic Susceptibility Anisotropy (MSA have been analysed in order to detect earthquake-induced deposits. We indentified 36 specific layers -Homogenites+Turbidites (HmTu - intercalated within continuous hemipelagictype sediments (biogenic or bio-induced fraction and fine-grained siliciclastic fraction. The whole succession is divided into a non-marine lower half and a marine upper half. The “events” are distributed through the entire core and they are composed of two terms: a coarse-grained lower term and an upper homogeneous fine-grained term, sharply separated. Their average time recurrence interval could be estimated for the entire MD01-2477 core. The non-marine and the marine sections yielded close estimated values for event recurrence times of around 400 yrs to 500 yrs.

  4. Sulforaphane inhibits TNF-α-induced adhesion molecule expression through the Rho A/ROCK/NF-κB signaling pathway.

    Science.gov (United States)

    Hung, Chi-Nan; Huang, Hui-Pei; Wang, Chau-Jong; Liu, Kai-Li; Lii, Chong-Kuei

    2014-10-01

    Endothelial dysfunction is an early indicator of cardiovascular diseases. Increased stimulation of tumor necrosis factor-α (TNF-α) triggers the inflammatory mediator secretion of endothelial cells, leading to atherosclerotic risk. In this study, we investigated whether sulforaphane (SFN) affected the expression of intracellular adhesion molecule-1 (ICAM-1) in TNF-α-induced ECV 304 endothelial cells. Our data showed that SFN attenuated TNF-α-induced expression of ICAM-1 in ECV 304 cells. Pretreatment of ECV 304 cells with SFN inhibited dose-dependently the secretion of proinflammatory cytokines, such as interleukin (IL)-1β, IL-6, and IL-8. SFN inhibited TNF-α-induced nuclear factor-κB (NF-κB) DNA binding activity. Furthermore, SFN decreased TNF-α-mediated phosphorylation of IκB kinase (IKK) and IκBα, Rho A, ROCK, ERK1/2, and plasminogen activator inhibitor-1 (PAI-1) levels. Collectively, SFN inhibited the NF-κB DNA binding activity and downregulated the TNF-α-mediated induction of ICAM-1 in endothelial cells by inhibiting the Rho A/ROCK/NF-κB signaling pathway, suggesting the beneficial effects of SFN on suppression of inflammation within the atherosclerotic lesion.

  5. Syneresis cracks: subaqueous shrinkage in argillaceous sediments caused by earthquake-induced dewatering

    Science.gov (United States)

    Pratt, Brian R.

    1998-04-01

    Syneresis cracks, often confused with subaerial desiccation phenomena, are traditionally ascribed to subaqueous shrinkage whereby salinity changes caused deflocculation of clay. This and other previously proposed mechanisms fail to account for their occurrence in low-energy, typically non-evaporitic facies, stratigraphically sporadic distribution, intrastratal formation under shallow burial depths, variation in morphology, degree of contraction, generation of sedimentary dikelets as crack fills, and deformation of dikelets and enclosing layers. Instead, it is suggested that ground motion from strong synsedimentary earthquakes caused argillaceous sediments to dewater, interbedded sands and silts to be almost simultaneously liquefied and injected into the resulting fissures, and then these dikelets to be distorted. Comparative rarity of syneresis cracks in Phanerozoic versus Precambrian marine strata is considered to be primarily an evolutionary consequence of theological changes caused by increased organic binding of clay flocs in the water column, greater input of organic matter into the sediment, and the diversification of sediment-dwelling bacteria and meiofauna in Phanerozoic deposits.

  6. Anthropogenic sources stimulate resonance of a natural rock bridge

    Science.gov (United States)

    Moore, Jeffrey R.; Thorne, Michael S.; Koper, Keith D.; Wood, John R.; Goddard, Kyler; Burlacu, Relu; Doyle, Sarah; Stanfield, Erik; White, Benjamin

    2016-09-01

    The natural modes of vibration of bedrock landforms, as well as the sources and effects of stimulated resonance remain poorly understood. Here we show that seismic energy created by an induced earthquake and an artificial reservoir has spectral content coincident with the natural modes of vibration of a prominent rock bridge. We measured the resonant frequencies of Rainbow Bridge, Utah using data from two broadband seismometers placed on the span, and identified eight distinct vibrational modes between 1 and 6 Hz. A distant, induced earthquake produced local ground motion rich in 1 Hz energy, stimulating a 20 dB increase in measured power at the bridge's fundamental mode. Moreover, we establish that wave action on Lake Powell, an artificial reservoir, generates microseismic energy with peak power ~1 Hz, also exciting resonance of Rainbow Bridge. These anthropogenic sources represent relatively new energy input for the bridge with unknown consequences for structural fatigue.

  7. Stress-induced electric current fluctuations in rocks: a superstatistical model

    Science.gov (United States)

    Cartwright-Taylor, Alexis; Vallianatos, Filippos; Sammonds, Peter

    2017-04-01

    We recorded spontaneous electric current flow in non-piezoelectric Carrara marble samples during triaxial deformation. Mechanical data, ultrasonic velocities and acoustic emissions were acquired simultaneously with electric current to constrain the relationship between electric current flow, differential stress and damage. Under strain-controlled loading, spontaneous electric current signals (nA) were generated and sustained under all conditions tested. In dry samples, a detectable electric current arises only during dilatancy and the overall signal is correlated with the damage induced by microcracking. Our results show that fracture plays a key role in the generation of electric currents in deforming rocks (Cartwright-Taylor et al., in prep). We also analysed the high-frequency fluctuations of these electric current signals and found that they are not normally distributed - they exhibit power-law tails (Cartwright-Taylor et al., 2014). We modelled these distributions with q-Gaussian statistics, derived by maximising the Tsallis entropy. This definition of entropy is particularly applicable to systems which are strongly correlated and far from equilibrium. Good agreement, at all experimental conditions, between the distributions of electric current fluctuations and the q-Gaussian function with q-values far from one, illustrates the highly correlated, fractal nature of the electric source network within the samples and provides further evidence that the source of the electric signals is the developing fractal network of cracks. It has been shown (Beck, 2001) that q-Gaussian distributions can arise from the superposition of local relaxations in the presence of a slowly varying driving force, thus providing a dynamic reason for the appearance of Tsallis statistics in systems with a fluctuating energy dissipation rate. So, the probability distribution for a dynamic variable, u under some external slow forcing, β, can be obtained as a superposition of temporary local

  8. A shallow aftershock sequence in the north-eastern end of the Wenchuan earthquake aftershock zone

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Previous studies show that mature faults are filled with fault gouge in the shallow part and thus cannot accumulate enough strain energy for earthquakes. Therefore most earthquakes are deeper than 5 km, except those events occurring on new faults or in intact rocks. From field observation, Wenchuan earthquake is found to rupture the free surface about 200 km, but the rupture may extend underground much further from teleseismic body waves inversion and aftershocks distribution. In the northeastern end of the rupture zone, deep rupture may induce stress increase near the free surface, and trigger shallow earthquakes. An Ms 5.7 aftershock occurred at Qingchuan, northeast end of Wenchuan earthquake fault on July 24, 2008, featuring thrust mechanism with a 3 km source centroid depth. The shallow focal depth is confirmed with the sPL phase recorded at station L0205. As Rayleigh wave is well only developed for source depth less than 1/5 of epicentral distance, the observed large amplitude of Rg at a distance of 15 km implied depth of 3 km or less. Dozens of aftershocks’ sPL waveforms are also analyzed to confirm the source depths less than 3 km. On the other hand, no surface ruptures are found by geological survey or InSAR studies. It is strongly suggested that these aftershock sequences initiate fresh rupture in intact rocks triggered by stress increase from the deep co-seismic rupture of the Wenchuan mainshock.

  9. Evolution of stress-induced borehole breakout in inherently anisotropic rock: Insights from discrete element modeling

    Science.gov (United States)

    Duan, K.; Kwok, C. Y.

    2016-04-01

    The aim of this study is to better understand the mechanisms controlling the initiation, propagation, and ultimate pattern of borehole breakouts in shale formation when drilled parallel with and perpendicular to beddings. A two-dimensional discrete element model is constructed to explicitly represent the microstructure of inherently anisotropic rocks by inserting a series of individual smooth joints into an assembly of bonded rigid discs. Both isotropic and anisotropic hollow square-shaped samples are generated to represent the wellbores drilled perpendicular to and parallel with beddings at reduced scale. The isotropic model is validated by comparing the stress distribution around borehole wall and along X axis direction with analytical solutions. Effects of different factors including the particle size distribution, borehole diameter, far-field stress anisotropy, and rock anisotropy are systematically evaluated on the stress distribution and borehole breakout propagation. Simulation results reveal that wider particle size distribution results in the local stress perturbations which cause localization of cracks. Reduction of borehole diameter significantly alters the crack failure from tensile to shear and raises the critical pressure. Rock anisotropy plays an important role on the stress state around wellbore which lead to the formation of preferred cracks under hydrostatic stress. Far-field stress anisotropy plays a dominant role in the shape of borehole breakout when drilled perpendicular to beddings while a secondary role when drilled parallel with beddings. Results from this study can provide fundamental insights on the underlying particle-scale mechanisms for previous findings in laboratory and field on borehole stability in anisotropic rock.

  10. Gorkha earthquake-induced landslides and dammed lakes: Evolution and outburst modeling

    Science.gov (United States)

    Shugar, D. H.; Immerzeel, W.; Wanders, N.; Kargel, J. S.; Leonard, G. J.; Haritashya, U. K.; Collins, B. D.

    2015-12-01

    On 25 April 2015, the Gorkha Earthquake (Mw 7.8) struck Nepal, generating thousands of landslides in Nepal, Tibet (China), and India. While the majority of these hazards were triggered co-seismically, many are considered secondary effects occurring during the weeks following the main shock, based on high-resolution WorldView satellite imagery. Here we report on a series of shallow, post-seismic landslides into the upper Marsyangdi River in the Annapurna region of the central Nepal Himalayas. These landslides constricted and blocked the river, causing impoundments that presented acute flood risks to communities downstream. On April 27, two days following the main shock, ~4.7 x 104 m3 of water was impounded behind a series of small constrictions. By May 28, the total volume of impounded water had increased to ~6.4 x 105 m3. The downstream flood risk was especially significant in the event of a domino-like cascade of dam breaches. We examine the timing, distribution and evolution of the landslide-dammed lakes and quantify the risk of inundation-scenarios to downstream communities with a hydrological model. The model uses a fully kinematic wave simulation at a 30 m-spatial and 2 sec-temporal resolution to resolve the height, timing and volume of a possible outburst flood wave. Our modeling shows that a rapid dam burst involving only the lowest, largest lake would increase water levels at the nearest village of Lower Pisang ~2 km downstream by >7m in a matter of minutes. Approximately 70 km downstream, the flood wave would be mostly attenuated, raising water levels only tens of centimeters. Fortunately, at the time of writing, no flood had occurred.

  11. TOWARDS A MORE EFFICIENT DETECTION OF EARTHQUAKE INDUCED FAÇADE DAMAGES USING OBLIQUE UAV IMAGERY

    Directory of Open Access Journals (Sweden)

    D. Duarte

    2017-08-01

    Full Text Available Urban search and rescue (USaR teams require a fast and thorough building damage assessment, to focus their rescue efforts accordingly. Unmanned aerial vehicles (UAV are able to capture relevant data in a short time frame and survey otherwise inaccessible areas after a disaster, and have thus been identified as useful when coupled with RGB cameras for façade damage detection. Existing literature focuses on the extraction of 3D and/or image features as cues for damage. However, little attention has been given to the efficiency of the proposed methods which hinders its use in an urban search and rescue context. The framework proposed in this paper aims at a more efficient façade damage detection using UAV multi-view imagery. This was achieved directing all damage classification computations only to the image regions containing the façades, hence discarding the irrelevant areas of the acquired images and consequently reducing the time needed for such task. To accomplish this, a three-step approach is proposed: i building extraction from the sparse point cloud computed from the nadir images collected in an initial flight; ii use of the latter as proxy for façade location in the oblique images captured in subsequent flights, and iii selection of the façade image regions to be fed to a damage classification routine. The results show that the proposed framework successfully reduces the extracted façade image regions to be assessed for damage 6 fold, hence increasing the efficiency of subsequent damage detection routines. The framework was tested on a set of UAV multi-view images over a neighborhood of the city of L’Aquila, Italy, affected in 2009 by an earthquake.

  12. Late Pleistocene-Holocene earthquake-induced slumps and soft-sediment deformation structures in the Acequion River valley, Central Precordillera, Argentina

    Directory of Open Access Journals (Sweden)

    Perucca Laura P

    2014-07-01

    Full Text Available Evidence of earthquake-induced liquefaction features in the Acequión river valley, central western Argentina, is analysed. Well-preserved soft-sediment deformation structures are present in Late Pleistocene deposits; they include two large slumps and several sand dikes, convolutions, pseudonodules, faults, dish structures and diapirs in the basal part of a shallow-lacustrine succession in the El Acequión River area. The water-saturated state of these sediments favoured deformation.

  13. shRNA沉默ROCK1和ROCK2表达对缺氧诱导的大鼠心肌细胞凋亡的影响%Effect of ROCK1 and ROCK2 silencing by shRNA on hypoxia-induced apoptosis of rat cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    孙国芳; 丁浩; 李菊香; 洪葵; 董家龙; 吴清华; 程晓曙

    2011-01-01

    目的:探讨Rho相关的卷曲蛋白激酶(ROCK1)和ROCK2在缺氧诱导的大鼠心肌细胞凋亡中的作用.方法:原代培养大鼠心肌细胞,并用抗α-横纹肌肌动蛋白免疫组化法进行鉴定.将ROCK1-shRNA和ROCK2-shRNA瞬时转染细胞,48 h后给予缺氧6 h处理.实验分为5组:(1)空白对照组;(2)缺氧组;(3)缺氧+阴性对照shRNA组;(4)缺氧+ROCK1-shRNA组;(5)缺氧+ROCK2-shRNA组.用倒置显微镜观察心肌细胞搏动频率与节律;用全自动生化分析仪测定细胞培养液中乳酸脱氢酶(LDH)含量;用MTT检测细胞存活率;用流式细胞仪检测细胞凋亡率;用Western blotting检测ROCK1和ROCK2的表达,并检测caspase-3和p-PI3K的表达情况.结果:鉴定证实大鼠心肌细胞原代培养成功.缺氧损伤后心肌细胞搏动频率较对照组明显减慢,搏动幅度减弱,节律不规整(P<0.01),而ROCK1-shRNA和ROCK2-shRNA的转染能抑制缺氧导致的这一作用(P<0.05或P<0.01).全自动生化分析仪检测发现,缺氧能导致细胞培养液LDH含量升高(P<0.01),而ROCK1-shRNA和ROCK2-shRNA的转染能抑制缺氧导致的这一作用(P<0.01).MTT检测发现,缺氧能导致心肌细胞存活率降低(P<0.05),而ROCK1-shRNA和ROCK2-shRNA的转染能抑制缺氧导致的这一作用(P<0.05).流式细胞仪检测发现,缺氧能导致心肌细胞凋亡率升高(P<0.01),而ROCK1-shRNA和ROCK2-shRNA的转染能抑制缺氧导致的这一作用(P<0.05或P<0.01).Western blotting检测发现,ROCK1-shRNA的转染能降低ROCK1的表达(P<0.05),ROCK2-shRNA的转染能降低ROCK2的表达(P<0.01);缺氧能导致caspase-3表达升高(P<0.05)、p-PI3K表达降低(P<0.01),ROCK1-shRNA和ROCK2-shRNA的转染能抑制缺氧导致的这一作用(P<0.05或P<0.01).结论:ROCK1和ROCK2表达下调能抑制缺氧损伤导致的大鼠心肌细胞凋亡,其机制与抑制caspase-3活化和增强p-PI3K的表达有关.%AIM: To investigate the effects of Rho - associated coiled - coil protein kinase - 1 ( R0CK1

  14. Flow mechanism of self-induced reversed limit-cycle wing rock for a chined forebody configuration

    Science.gov (United States)

    Shi, Wei; Deng, Xueying; Wang, Yankui; Li, Qian

    2015-11-01

    The wing rock phenomenon reduces the maneuverability and affects the flight safety of modern advanced fighters, such as the F-35, which have chined forebodies. Understanding the flow mechanism is critical to suppressing this phenomenon. In this study, experiments were conducted to reveal the motion and flow behavior over a chined forebody configuration. The tests were performed in a wind tunnel at an angle of attack of 50∘ with a Reynolds number of 1.87 × 105. Reversed limit-cycle oscillation was discovered in the free-to-roll tests. The unstable rolling moment around zero roll angle in the static case suggests that the model tends to be driven away from zero roll angle. Thus, the model cannot maintain its equilibrium at zero roll angle during free-to-roll motion. The unstable rolling moment is generated by the wing vortex structure above the upward wing, which is induced by the forebody asymmetric vortices. During wing rock, the wing vortex structure appears above the upward wing at a large roll angle after crossing zero roll angle owing to a time lag in the forebody vortex position, which is conducive to the motion. The forebody asymmetric vortices are thus the key to induce and maintain the motion.

  15. Insights into induced earthquakes and aftershock activity with in-situ measurements of seismic velocity variations in an active underground mine

    Science.gov (United States)

    Brenguier, F.; Olivier, G.; Campillo, M.; Roux, P.; Shapiro, N.; Lynch, R.

    2015-12-01

    The behaviour of the crust shortly after large earthquakes has been the subject of numerous studies, but many co- and post-seismic processes remain poorly understood. Damage and healing of the bulk rock mass, post-seismic deformation and the mechanisms of earthquake triggering are still not well understood. These processes are important to properly model and understand the behaviour of faults and earthquake cycles.In this presentation, we will show how in-situ measurements of seismic velocity variations have given new insights into these co- and post-seismic processes. An experiment was performed where a blast was detonated in a tunnel in an underground mine, while seismic velocity variations were accurately (0.005 %) measured with ambient seismic noise correlations. Additionally, aftershock activity was examined and the influence of the removal of a piece of solid rock was estimated with elastic static stress modelling. The majority of the aftershocks were delayed with respect to the passing of the dynamic waves from the blast, while the locations of the aftershocks appeared clustered and not homogeneously spread around the blast location. A significant velocity drop is visible during the time of the blast, which is interpreted as co-seismic damage and plastic deformation. These non-elastic effects are healed by the confining stresses over a period of 5 days until the seismic velocity converges to a new baseline level. The instantaneous weakening and gradual healing observed from the velocity variations are qualitatively similar to results reported in laboratory studies. The change in the baseline level of the seismic velocity before and after the blast indicate a change in the static stress that is comparable to the results of elastic static stress modelling. The differences between the elastic model predictions and the seismic velocity variations could be due to zones of fractured rock, indicated by the spatial clustering of the aftershocks, that are not

  16. Tepees in peritidal carbonates: origin via earthquake-induced deformation, with example from the Middle Cambrian of western Canada

    Science.gov (United States)

    Pratt, Brian R.

    2002-11-01

    Tepee structures are common in many ancient carbonate tidal flat successions, and because analogues are known from tropical coastal areas, they are well established as evidence for synsedimentary lithification of subaerially exposed carbonate sediment. Existing explanations involving desiccation, thermal expansion and contraction, fluctuating groundwater pore pressure or diagenetic force of crystallization do not adequately account for the style and degree of deformation seen in some examples, such as those in the Middle Cambrian Cathedral Formation of the southern Rocky Mountains, western Canada. These tepees provide evidence for essentially instantaneous events causing brittle failure of decimetre-thick crusts of ooidal and pisoidal grainstone, followed by their dilation, rupturing, separation, tilting and shingling. They can be explained as breccias generated by sporadic episodes of strong ground motion from earthquakes that emanated from a syndepositionally active fault system nearby. Variably directed tensile and compressive stresses broke crusts, shifted them upwards and shuffled them laterally. Subsequent microbial encrustation and vigorous flushing by seawater in the resulting shelter cavities led to rapid stabilization by cementation. Recognition of the role of seismically induced deformation in explaining some tepee structures furnishes a proxy for synsedimentary tectonism and adds another member to the family of 'seismites' which reflect a range of rheological properties of unlithified and lithifying sediments.

  17. Pre-earthquake Magnetic Pulses

    CERN Document Server

    Scoville, John; Freund, Friedemann

    2014-01-01

    A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are observable because their extremely long wavelength allows them to pass through the Earth's crust. Interestingly, the source of these pulses may be triangulated to pinpoint locations where stress is building deep within the crust. We couple a semiconductor drift-diffusion model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

  18. Permanent Seismically Induced Displacement of Rock-Founded Structures Computed by the Newmark Program

    Science.gov (United States)

    2009-02-01

    reasonably be expected to be generated on a specific source, on the basis of seismological and geological evidence. Significant damage resulting from an...crust. This current preferred scale in engineering seismology is the moment magnitude scale (Mw) and necessarily involves backwards assignment to...36.4 -27.7 10.61 -11.37 57.2 47.2 1.97 3.36 107.28 17.3 Rock Iprina, Italy H1 0 XX-XX-9.5 Iprina, Italy 11/23/1980 ENEL, Struno, Italy 44

  19. Non-tectonic liquefaction-induced large surface displacements in the Aso Valley, Japan, caused by the 2016 Kumamoto earthquake, revealed by ALOS-2 SAR

    Science.gov (United States)

    Fujiwara, Satoshi; Morishita, Yu; Nakano, Takayuki; Kobayashi, Tomokazu; Yarai, Hiroshi

    2017-09-01

    We constructed and analyzed full 3-D ground surface displacement field associated with the 2016 Kumamoto (Japan) earthquake using satellite radar images from ALOS-2. Displacements reflect not only tectonic crustal deformation caused by main earthquake faults but also non-tectonic surface deformations. The largest deformations in the earthquake sequence were found in the Aso Valley, along the NW outer rim of the Mt. Aso caldera. Large, independent surface deformations occurred in three areas with diameters of 500 m-2 km in the Aso Valley, and each area was horizontally displaced by more than 2 m to the NNW. These areas are underlain by thick lake-bottom deposits of saturated silt with low penetration resistance. As the direction of the displacements was parallel to the ground slope in each area, the strong seismic motion of the earthquake most probably induced liquefaction in the lake-bottom deposits and the ground surface slid horizontally along the slope on the liquefied silt. Because the areas of the large displacements are closely related to the thickness and shape of the lake-bottom deposits, amplification of the seismic wave in these deposits likely contributed to the liquefaction. A seismograph installed at the Aso Valley recorded co-seismic movement within several seconds of the main shock, indicating a possibility of the strong seismic motion amplifying the horizontal displacement of this area. On the SSE side of the deformed areas, numerous graben-like ruptures developed. As these ruptures are caused by surface tension during the large horizontal displacement, they are not earthquake fault traces and the process of this deformation is non-tectonic.

  20. Preliminary remote sensing assessment of the catastrophic avalanche in Langtang Valley induced by the 2015 Gorkha earthquake, Nepal

    Science.gov (United States)

    Nagai, Hiroto; Watanabe, Manabu; Tomii, Naoya

    2016-04-01

    A major earthquake, measuring 7.8 Mw, occurred on April 25, 2015, in Lamjung district, central Nepal, causing more than 9,000 deaths and 23,000 injuries. During the event, termed the 2015 Gorkha earthquake, the most catastrophic collapse of the mountain side was reported in the Langtang Valley, located 60 km north of Kathmandu. In this collapse, a huge boulder-rich avalanche and a sudden air pressure wave traveled from a steep south-facing slope to the bottom of a U-shaped valley, resulting in more than 170 deaths. Accurate in-situ surveys are necessary to investigate such events, and to find out ways to avoid similar catastrophic events in the future. Geospatial information obtained from multiple satellite observations is invaluable for such surveys in remote mountain regions. In this study, we (1) identify the collapsed sediment using synthetic aperture radar, (2) conduct detailed mapping using high-resolution optical imagery, and (3) estimate sediment volumes from digital surface models in order to quantify the immediate situation of the avalanched sediment. (1) Visual interpretation and coherence calculations using Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) images give a consistent area of sediment cover. Emergency observation was carried out the day after the earthquake, using the PALSAR-2 onboard the Advanced Land Observing Satellite-2 (ALOS-2, "DAICHI-2"). Visual interpretation of orthorectified backscatter amplitude images revealed completely altered surface features, over which the identifiable sediment cover extended for 0.73 km2 (28°13'N, 85°30'E). Additionally, measuring the decrease in normalized coherence quantifies the similarity between the pre- and post-event surface features, after the removal of numerous noise patches by focal statistics. Calculations within the study area revealed high-value areas corresponding to the visually identified sediment area. Visual interpretation of the amplitude images and the coherence

  1. AAV.shRNA-mediated downregulation of ROCK2 attenuates degeneration of dopaminergic neurons in toxin-induced models of Parkinson's disease in vitro and in vivo.

    Science.gov (United States)

    Saal, Kim-Ann; Koch, Jan C; Tatenhorst, Lars; Szegő, Eva M; Ribas, Vinicius Toledo; Michel, Uwe; Bähr, Mathias; Tönges, Lars; Lingor, Paul

    2015-01-01

    Parkinson's disease (PD) is a neurodegenerative disorder with prominent neuronal cell death in the substantia nigra (SN) and other parts of the brain. Previous studies in models of traumatic and neurodegenerative CNS disease showed that pharmacological inhibition of Rho-associated kinase (ROCK), a molecule involved in inhibitory signaling in the CNS, by small-molecule inhibitors improves neuronal survival and increases regeneration. Most small-molecule inhibitors, however, offer only limited target specificity and also inhibit other kinases, including both ROCK isoforms. To establish the role of the predominantly brain-expressed ROCK2 isoform in models of regeneration and PD, we used adeno-associated viral vectors (AAV) to specifically knockdown ROCK2 in neurons. Rat primary midbrain neurons (PMN) were transduced with AAV expressing short-hairpin-RNA (shRNA) against ROCK2 and LIM-domain kinase 1 (LIMK1), one of the downstream targets of ROCK2. While knock-down of ROCK2 and LIMK1 both enhanced neurite regeneration in a traumatic scratch lesion model, only ROCK2-shRNA protected PMN against 1-methyl-4-phenylpyridinium (MPP+) toxicity. Moreover, AAV.ROCK2-shRNA increased levels of the pro-survival markers Bcl-2 and phospho-Erk1. In vivo, AAV.ROCK2-shRNA vectors were injected into the ipsilateral SN and a unilateral 6-OHDA striatal lesion was performed. After four weeks, behavioral, immunohistochemical and biochemical alterations were investigated. Downregulation of ROCK2 protected dopaminergic neurons in the SN from 6-OHDA-induced degeneration and resulted in significantly increased TH-positive neuron numbers. This effect, however, was confined to nigral neuronal somata as striatal terminal density, dopamine and metabolite levels were not significantly preserved. Interestingly, motor behavior was improved in the ROCK2-shRNA treated animals compared to control after four weeks. Our studies thus confirm ROCK2 as a promising therapeutic target in models of PD and

  2. Stresses induced by post-tensioned anchor in jointed rock mass

    Institute of Scientific and Technical Information of China (English)

    Alan Showkati; Parviz Maarefvand; Hossein Hassani

    2015-01-01

    A new analytical study on stresses around a post-tensioned anchor in rocks with two perpendicular joint sets is presented. The assumptions of orthotropic elastic rock with plane strain conditions are made in derivation of the formulations. A tri-linear bond-slip constitutive law is used for modeling the tendon-grout interface behavior and debonding of this interface. The bearing plate width is also considered in the analysis. The obtained solutions are in the integral forms and numerical techniques that have been used for evaluation. In the illustrative example given, the major principal stress is compressive in the anchor free zone and compressive stress concentrations of 815 kPa and 727 kPa (for the anchor load of 300 kN) are observed under the bearing plate and the bond length proximal end, respectively. However, large values of tensile stresses with the maximum of−434 kPa are formed at the bond length distal end. The results obtained using the proposed solution are compared very those of numerical method (FEM).

  3. Charles Darwin's earthquake reports

    Science.gov (United States)

    Galiev, Shamil

    2010-05-01

    problems which began to discuss only during the last time. Earthquakes often precede volcanic eruptions. According to Darwin, the earthquake-induced shock may be a common mechanism of the simultaneous eruptions of the volcanoes separated by long distances. In particular, Darwin wrote that ‘… the elevation of many hundred square miles of territory near Concepcion is part of the same phenomenon, with that splashing up, if I may so call it, of volcanic matter through the orifices in the Cordillera at the moment of the shock;…'. According to Darwin the crust is a system where fractured zones, and zones of seismic and volcanic activities interact. Darwin formulated the task of considering together the processes studied now as seismology and volcanology. However the difficulties are such that the study of interactions between earthquakes and volcanoes began only recently and his works on this had relatively little impact on the development of geosciences. In this report, we discuss how the latest data on seismic and volcanic events support the Darwin's observations and ideas about the 1835 Chilean earthquake. The material from researchspace. auckland. ac. nz/handle/2292/4474 is used. We show how modern mechanical tests from impact engineering and simple experiments with weakly-cohesive materials also support his observations and ideas. On the other hand, we developed the mathematical theory of the earthquake-induced catastrophic wave phenomena. This theory allow to explain the most important aspects the Darwin's earthquake reports. This is achieved through the simplification of fundamental governing equations of considering problems to strongly-nonlinear wave equations. Solutions of these equations are constructed with the help of analytic and numerical techniques. The solutions can model different strongly-nonlinear wave phenomena which generate in a variety of physical context. A comparison with relevant experimental observations is also presented.

  4. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.

  5. Uranium groundwater anomalies and L'Aquila earthquake, 6th April 2009 (Italy).

    Science.gov (United States)

    Plastino, Wolfango; Povinec, Pavel P; De Luca, Gaetano; Doglioni, Carlo; Nisi, Stefano; Ioannucci, Luca; Balata, Marco; Laubenstein, Matthias; Bella, Francesco; Coccia, Eugenio

    2010-01-01

    Monitoring of chemical and physical groundwater parameters has been carried out worldwide in seismogenic areas with the aim to test possible correlations between their spatial and temporal variations and strain processes. Uranium (U) groundwater anomalies were observed during the preparation phases of the recent L'Aquila earthquake of 6th April 2009 in the cataclastic rocks near the overthrust fault crossing the deep underground Gran Sasso National Laboratory. The results suggest that U may be used as a potential strain indicator of geodynamic processes occurring before the seismic swarm and the main earthquake shock. Moreover, this justifies the different radon patterns before and after the main shock: the radon releases during and after the earthquake are much than more during the preparatory period because the process does not include only the microfracturing induced by stress-strain activation, but also radon increases accompanying groundwater U anomalies.

  6. Characteristics of Induced and Tectonic Seismicity in Oklahoma Based on High-precision Earthquake Relocations and Focal mechanisms

    Science.gov (United States)

    Aziz Zanjani, F.; Lin, G.

    2016-12-01

    Seismic activity in Oklahoma has greatly increased since 2013, when the number of wastewater disposal wells associated with oil and gas production was significantly increased in the area. An M5.8 earthquake at about 5 km depth struck near Pawnee, Oklahoma on September 3, 2016. This earthquake is postulated to be related with the anthropogenic activity in Oklahoma. In this study, we investigate the seismic characteristics in Oklahoma by using high-precision earthquake relocations and focal mechanisms. We acquire the seismic data between January 2013 and October 2016 recorded by the local and regional (within 200 km distance from the Pawnee mainshock) seismic stations from the Incorporated Research Institutions for Seismology (IRIS). We relocate all the earthquakes by applying the source-specific station term method and a differential time relocation method based on waveform cross-correlation data. The high-precision earthquake relocation catalog is then used to perform full-waveform modeling. We use Muller's reflection method for Green's function construction and the mtinvers program for moment tensor inversion. The sensitivity of the solution to the station and component distribution is evaluated by carrying out the Jackknife resampling. These earthquake relocation and focal mechanism results will help constrain the fault orientation and the earthquake rupture length. In order to examine the static Coulomb stress change due to the 2016 Pawnee earthquake, we utilize the Coulomb 3 software in the vicinity of the mainshock and compare the aftershock pattern with the calculated stress variation. The stress change in the study area can be translated into probability of seismic failure on other parts of the designated fault.

  7. Complete Coulomb stress changes induced by the Ms7.6 earthquake in Lancang-Gengma, Yunnan and triggering of aftershocks by dynamic and static stress

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The spatiotemporal evolution patterns of complete Coulomb stress changes caused by 1988 Ms7.6 earthquake in Lancang-Gengma,Yunnan,are calculated and studied.And the triggering problems of Ms7.2 Gengma shock occurring 13 minutes after the main shock and of Ms5.0―6.9 aftershocks within 24 days after the main shock are discussed.The results show that the spatial distribution patterns of complete Coulomb stress changes of the Ms7.6 main shock are strongly asymmetric.The areas of positive dynamic and static Coulomb stress are both coincident well with the strong aftershocks' locations.The Ms7.2 Gengma shock and most of strong aftershocks are subjected to the triggering effect of dynamic and static Coulomb stresses induced by the Ms7.6 Lancang earthquake.

  8. Seismic wave attenuation and dispersion due to wave-induced fluid flow in rocks with strong permeability fluctuations.

    Science.gov (United States)

    Germán Rubino, J; Monachesi, Leonardo B; Müller, Tobias M; Guarracino, Luis; Holliger, Klaus

    2013-12-01

    Oscillatory fluid movements in heterogeneous porous rocks induced by seismic waves cause dissipation of wave field energy. The resulting seismic signature depends not only on the rock compressibility distribution, but also on a statistically averaged permeability. This so-called equivalent seismic permeability does not, however, coincide with the respective equivalent flow permeability. While this issue has been analyzed for one-dimensional (1D) media, the corresponding two-dimensional (2D) and three-dimensional (3D) cases remain unexplored. In this work, this topic is analyzed for 2D random medium realizations having strong permeability fluctuations. With this objective, oscillatory compressibility simulations based on the quasi-static poroelasticity equations are performed. Numerical analysis shows that strong permeability fluctuations diminish the magnitude of attenuation and velocity dispersion due to fluid flow, while the frequency range where these effects are significant gets broader. By comparing the acoustic responses obtained using different permeability averages, it is also shown that at very low frequencies the equivalent seismic permeability is similar to the equivalent flow permeability, while for very high frequencies this parameter approaches the arithmetic average of the permeability field. These seemingly generic findings have potentially important implications with regard to the estimation of equivalent flow permeability from seismic data.

  9. Coseismic changes of gravitational potential energy induced by global earthquakes based on spherical-Earth elastic dislocation theory

    Science.gov (United States)

    Xu, Changyi; Chao, B. Fong

    2017-05-01

    We compute the coseismic gravitational potential energy Eg change using the spherical-Earth elastic dislocation theory and either the fault model treated as a point source or the finite fault model. The rate of the accumulative Eg loss produced by historical earthquakes from 1976 to 2016 (about 42,000 events) using the Global Centroid Moment Tensor Solution catalogue is estimated to be on the order of -2.1 × 1020 J/a, or -6.7 TW (1 TW = 1012 W), amounting to 15% in the total terrestrial heat flow. The energy loss is dominated by the thrust faulting, especially the megathrust earthquakes such as the 2004 Sumatra earthquake (Mw 9.0) and the 2011 Tohoku-Oki earthquake (Mw 9.1). It is notable that the very deep focus events, the 1994 Bolivia earthquake (Mw 8.2) and the 2013 Okhotsk earthquake (Mw 8.3), produced significant overall coseismic Eg gain according to our calculation. The accumulative coseismic Eg is mainly lost in the mantle of the Earth and also lost in the core of the Earth but with a relatively smaller magnitude. By contrast, the crust of the Earth gains gravitational potential energy cumulatively because of the coseismic deformations. We further investigate the tectonic signature in the coseismic crustal Eg changes in some complex tectonic zone, such as Taiwan region and the northeastern margin of the Tibetan Plateau. We found that the coseismic Eg change is consistent with the regional tectonic character.

  10. Delay-induced transport in a rocking ratchet under feedback control.

    Science.gov (United States)

    Loos, Sarah A M; Gernert, Robert; Klapp, Sabine H L

    2014-05-01

    Based on the Fokker-Planck equation we investigate the transport of an overdamped colloidal particle in a static, asymmetric periodic potential supplemented by a time-dependent, delayed feedback force, F(fc). For a given time t, F(fc) depends on the status of the system at a previous time t-τ(D), with τ(D) being a delay time, specifically on the delayed mean particle displacement (relative to some "switching position"). For nonzero delay times F(fc)(t) develops nearly regular oscillations, generating a net current in the system. Depending on the switching position, this current is nearly as large or even larger than that in a conventional open-loop rocking ratchet. We also investigate thermodynamic properties of the delayed nonequilibrium system and we suggest an underlying Langevin equation which reproduces the Fokker-Planck results.

  11. Bacterially induced weathering of ultramafic rock and its implications for phytoextraction.

    Science.gov (United States)

    Becerra-Castro, Cristina; Kidd, Petra; Kuffner, Melanie; Prieto-Fernández, Ángeles; Hann, Stephan; Monterroso, Carmela; Sessitsch, Angela; Wenzel, Walter; Puschenreiter, Markus

    2013-09-01

    The bioavailability of metals in soil is often cited as a limiting factor of phytoextraction (or phytomining). Bacterial metabolites, such as organic acids, siderophores, or biosurfactants, have been shown to mobilize metals, and their use to improve metal extraction has been proposed. In this study, the weathering capacities of, and Ni mobilization by, bacterial strains were evaluated. Minimal medium containing ground ultramafic rock was inoculated with either of two Arthrobacter strains: LA44 (indole acetic acid [IAA] producer) or SBA82 (siderophore producer, PO4 solubilizer, and IAA producer). Trace elements and organic compounds were determined in aliquots taken at different time intervals after inoculation. Trace metal fractionation was carried out on the remaining rock at the end of the experiment. The results suggest that the strains act upon different mineral phases. LA44 is a more efficient Ni mobilizer, apparently solubilizing Ni associated with Mn oxides, and this appeared to be related to oxalate production. SBA82 also leads to release of Ni and Mn, albeit to a much lower extent. In this case, the concurrent mobilization of Fe and Si indicates preferential weathering of Fe oxides and serpentine minerals, possibly related to the siderophore production capacity of the strain. The same bacterial strains were tested in a soil-plant system: the Ni hyperaccumulator Alyssum serpyllifolium subsp. malacitanum was grown in ultramafic soil in a rhizobox system and inoculated with each bacterial strain. At harvest, biomass production and shoot Ni concentrations were higher in plants from inoculated pots than from noninoculated pots. Ni yield was significantly enhanced in plants inoculated with LA44. These results suggest that Ni-mobilizing inoculants could be useful for improving Ni uptake by hyperaccumulator plants.

  12. Dynamic Source Inversion of Intermediate Depth Earthquakes in Mexico

    Science.gov (United States)

    Yuto Sho Mirwald, Aron; Cruz-Atienza, Victor Manuel; Krishna Singh-Singh, Shri

    2017-04-01

    The source mechanisms of earthquakes at intermediate depth (50-300 km) are still under debate. Due to the high confining pressure at depths below 50 km, rocks ought to deform by ductile flow rather than brittle failure, which is the mechanism originating most earthquakes. Several source mechanisms have been proposed, but for neither of them conclusive evidence has been found. One of two viable mechanisms is Dehydration Embrittlement, where liberation of water lowers the effective pressure and enables brittle fracture. The other is Thermal Runaway, a highly localized ductile deformation (Prieto et. al., Tecto., 2012). In the Mexican subduction zone, intermediate depth earthquakes represent a real hazard in central Mexico due to their proximity to highly populated areas and the large accelerations induced on ground motion (Iglesias et. al., BSSA, 2002). To improve our understanding of these rupture processes, we use a recently introduced inversion method (Diaz-Mojica et. al., JGR, 2014) to analyze several intermediate depth earthquakes in Mexico. The method inverts strong motion seismograms to determine the dynamic source parameters based on a genetic algorithm. It has been successfully used for the M6.5 Zumpango earthquake that occurred at a depth of 62 km in the state of Guerrero, Mexico. For this event, high radiated energy, low radiation efficiency and low rupture velocity were determined. This indicates a highly dissipative rupture process, suggesting that Thermal Runaway could probably be the dominant source process. In this work we improved the inversion method by introducing a theoretical consideration for the nucleation process that minimizes the effects of rupture initiation and guarantees self-sustained rupture propagation (Galis et. al., GJInt., 2014). Preliminary results indicate that intermediate depth earthquakes in central Mexico may vary in their rupture process. For instance, for a M5.9 normal-faulting earthquake at 55 km depth that produced very

  13. Laboratory simulations of fluid/gas induced micro-earthquakes: application to volcano seismology.

    Directory of Open Access Journals (Sweden)

    Philip Michael Benson

    2014-11-01

    Full Text Available Understanding different seismic signals recorded in active volcanic regions allows geoscientists to derive insight into the processes that generate them. A key type is known as Low Frequency or Long Period (LP event, generally understood to be generated by different fluid types resonating in cracks and faults. The physical mechanisms of these signals have been linked to either resonance/turbulence within fluids, or as a result of fluids ‘sloshing’ due to a mixture of gas and fluid being present in the system. Less well understood, however, is the effect of the fluid type (phase on the measured signal. To explore this, we designed an experiment in which we generated a precisely controlled liquid to gas transition in a closed system by inducing rapid decompression of fluid-filled fault zones in a sample of basalt from Mt. Etna Volcano, Italy. We find that fluid phase transition is accompanied by a marked frequency shift in the accompanying microseismic dataset that can be compared to volcano seismic data. Moreover, our induced seismic activity occurs at pressure conditions equivalent to hydrostatic depths of 200 to 750 meters. This is consistent with recently measured dominant frequencies of LP events and with numerous models.

  14. The large-scale shaking table test study of dynamic response and failure mode of bedding rock slope under earthquake%地震作用下顺层岩质边坡动力响应和破坏模式大型振动台试验研究

    Institute of Scientific and Technical Information of China (English)

    董金玉; 杨国香; 伍法权; 祁生文

    2011-01-01

    It is necessary to study bedding rock landslides induced by "5-12" Wenchuan earthquake. According to the similar relationship of dynamic model test, a bedding model slope is built with a height of 1.6 m, length of 1.75 m, width of 0.8 m and a slope angle larger than the dip angle of the rock stratum. A large-scale shaking table test of the model slope is performed. The results show that amplification coefficients of the acceleration along slope surface and in vertical direction increase with the elevation increasing. And its increment speeds also increase with the elevation increasing. At the same elevation, the amplification coefficients of the acceleration on slope surface are larger than that in slope body. The input frequency of seismic waves has obvious effects on dynamic responses of slope. The amplification effect of acceleration enhances evidently with the frequency increasing and approach to the natural frequency of the model slope. The amplification coefficients of the acceleration decrease with the earthquake amplitudes increasing. Comparing with the acceleration monitoring data obtained by the shaking table test of the homogeneous slope, it is found that structural surface of the slope also has effects on the amplification coefficients of the acceleration. Because of reflection and refraction of structural surface, the amplification effect of acceleration enhances evidently. Based on analysis of failure features of the slope, the failure process is described as earthquake induction-loosening of rock mass and tensile failure of the crest of the slope-propagation and coalescence of cracks in the middle part of slope surface-occurrence of high locality landslide-formation of debris flow-accumulation at the slope toe. The study results are helpful to reveal the formation mechanism of landslide under earthquake and provide valuable references for disaster prevention and reduction.%5·12汶川大地震触发了大量的顺层岩质滑坡,对其进行研究

  15. Earthquakes triggered by fluid extraction

    Science.gov (United States)

    Segall, P.

    1989-01-01

    Seismicity is correlated in space and time with production from some oil and gas fields where pore pressures have declined by several tens of megapascals. Reverse faulting has occurred both above and below petroleum reservoirs, and normal faulting has occurred on the flanks of at least one reservoir. The theory of poroelasticity requires that fluid extraction locally alter the state of stress. Calculations with simple geometries predict stress perturbations that are consistent with observed earthquake locations and focal mechanisms. Measurements of surface displacement and strain, pore pressure, stress, and poroelastic rock properties in such areas could be used to test theoretical predictions and improve our understanding of earthquake mechanics. -Author

  16. Pre-earthquake magnetic pulses

    Directory of Open Access Journals (Sweden)

    J. Scoville

    2014-12-01

    Full Text Available A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are generated deep in the Earth's crust, in and around the Hypocentral volume, days or even weeks before Earthquakes. They are observable at the surface because their extremely long wavelength allows them to pass through kilometers of rock. Interestingly, the source of these pulses may be triangulated to pinpoint locations where stresses are building deep within the crust. We couple a semiconductor drift-diffusion model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

  17. Long-term blood pressure changes induced by the 2009 L'Aquila earthquake: assessment by 24 h ambulatory monitoring.

    Science.gov (United States)

    Giorgini, Paolo; Striuli, Rinaldo; Petrarca, Marco; Petrazzi, Luisa; Pasqualetti, Paolo; Properzi, Giuliana; Desideri, Giovambattista; Omboni, Stefano; Parati, Gianfranco; Ferri, Claudio

    2013-09-01

    An increased rate of cardiovascular and cerebrovascular events has been described during and immediately after earthquakes. In this regard, few data are available on long-term blood pressure control in hypertensive outpatients after an earthquake. We evaluated the long-term effects of the April 2009 L'Aquila earthquake on blood pressure levels, as detected by 24 h ambulatory blood pressure monitoring. Before/after (mean±s.d. 6.9±4.5/14.2±5.1 months, respectively) the earthquake, the available 24 h ambulatory blood pressure monitoring data for the same patients were extracted from our database. Quake-related daily life discomforts were evaluated through interviews. We enrolled 47 patients (25 female, age 52±14 years), divided into three groups according to antihypertensive therapy changes after versus before the earthquake: unchanged therapy (n=24), increased therapy (n=17) and reduced therapy (n=6). Compared with before the quake, in the unchanged therapy group marked increases in 24 h (P=0.004), daytime (P=0.01) and nighttime (P=0.02) systolic blood pressure were observed after the quake. Corresponding changes in 24 h (P=0.005), daytime (P=0.01) and nighttime (P=0.009) diastolic blood pressure were observed. Daily life discomforts were reported more frequently in the unchanged therapy and increased therapy groups than the reduced therapy group (P=0.025 and P=0.018, respectively). In conclusion, this study shows that patients with unchanged therapy display marked blood pressure increments up to more than 1 year after an earthquake, as well as long-term quake-related discomfort. Our data suggest that particular attention to blood pressure levels and adequate therapy modifications should be considered after an earthquake, not only early after the event but also months later.

  18. Geomagnetic signal induced by the M5.7 earthquake occurred on September 24-th, 2016, in the seismic active Vrancea zone, Romania

    Science.gov (United States)

    Stanica, Dumitru; Armand Stanica, Dragos

    2017-04-01

    In this paper, we used the geomagnetic time series collected in real time by the electromagnetic monitoring system, placed at the Geomagnetic Observatory Provita de Sus, to emphasize possible relationships between the pre-seismic anomalous behavior of the normalized function Bzn and M5.7 earthquake occurrence in Vrancea seismic active zone, on September 24, 2016. It has already been demonstrated (Stanica and Stanica, 2012, Stanica et al., 2015) that for a 2D geoelectric structure, in pre-seismic conditions, the normalized function Bzn has significant changes in magnitudes due to the electrical conductivity changes, possibly associated with the earthquake-induced rupture-processes and high-pressure fluid flow through the faulting systems developed inside the Vrancea seismogenic volume and along the Carpathian electrical conductivity anomaly. In this circumstances, the daily mean distributions of the Bzn = Bz/Bperp (where Bz is vertical component of the geomagnetic field; Bperp is geomagnetic component perpendicular to the geoelectric strike) and its standard deviation (SD) are performed in the ULF frequency range 0.001Hz to 0.0083Hz by using both the FFT band-pass filter analysis and statistical analysis based on a standardized random variable equation. After analyzing the pre-seismic anomalous intervals, a pre-seismic geomagnetic signal greater than 5 SD was identified on September 22, 2016, what means a lead time of 2 days before the M5.7 earthquake occurred on September 24, emphasized in real time on the web site (www.geodin.ro). The final conclusion is that the proposed geomagnetic methodology might be used to provide suitable information for the extreme seismic hazard assessment and risk mitigation. References: Dumitru Stanica and Dragos Armand Stanica, Earthquakes precursors, in "Earthquake Research and Analysis-Statistical Studies, Observations and Planning" Book 5, edited by: Dr. Sebastiano D'Amico, ISBN 978-953-51-0134-5, InTech open access publisher

  19. Rupture, waves and earthquakes

    Science.gov (United States)

    UENISHI, Koji

    2017-01-01

    Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but “extraordinary” phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable. PMID:28077808

  20. Rupture, waves and earthquakes.

    Science.gov (United States)

    Uenishi, Koji

    2017-01-01

    Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but "extraordinary" phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable.

  1. Exploratory electromyography in the study of vibration-induced white finger in rock drillers

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, D.S.; Barwick, D.D.; Petrie, A.

    1982-02-01

    Electrophysiological observations made in the hands of a group of 16 rock-drillers were compared with 15 controls. Motor and sensory conduction velocities in the median and ulnar nerves together with the latency, duration, and amplitude of the evoked action potentials were measured. The differences between the groups were statistically significant mainly in latency, duration, and amplitude, especially of the sensory action potentials. Measurement of the conduction velocities, in general, proved to be less sensitive, and the only significant change observed was in the sensory conduction velocity in the median nerve when the first digit in the right hand was stimulated. The most interesting result was evidence of an increased prevalence of possible carpal tunnel syndrome in the exposed (44% compared with 7% in the control group). A similar set of data, but exclusively sensory and not standardised for age and sex, was obtained from 25 university students for comparison with the assigned groups. The results showed that apart from sensory duration the control group had values that were closest to the students while the vibration group had values furthest away.

  2. Earthquake damage to underground facilities

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, H.R.; Hustrulid, W.A. Stephenson, D.E.

    1978-11-01

    The potential seismic risk for an underground nuclear waste repository will be one of the considerations in evaluating its ultimate location. However, the risk to subsurface facilities cannot be judged by applying intensity ratings derived from the surface effects of an earthquake. A literature review and analysis were performed to document the damage and non-damage due to earthquakes to underground facilities. Damage from earthquakes to tunnels, s, and wells and damage (rock bursts) from mining operations were investigated. Damage from documented nuclear events was also included in the study where applicable. There are very few data on damage in the subsurface due to earthquakes. This fact itself attests to the lessened effect of earthquakes in the subsurface because mines exist in areas where strong earthquakes have done extensive surface damage. More damage is reported in shallow tunnels near the surface than in deep mines. In mines and tunnels, large displacements occur primarily along pre-existing faults and fractures or at the surface entrance to these facilities.Data indicate vertical structures such as wells and shafts are less susceptible to damage than surface facilities. More analysis is required before seismic criteria can be formulated for the siting of a nuclear waste repository.

  3. Earthquake potential revealed by tidal influence on earthquake size-frequency statistics

    Science.gov (United States)

    Ide, Satoshi; Yabe, Suguru; Tanaka, Yoshiyuki

    2016-11-01

    The possibility that tidal stress can trigger earthquakes is long debated. In particular, a clear causal relationship between small earthquakes and the phase of tidal stress is elusive. However, tectonic tremors deep within subduction zones are highly sensitive to tidal stress levels, with tremor rate increasing at an exponential rate with rising tidal stress. Thus, slow deformation and the possibility of earthquakes at subduction plate boundaries may be enhanced during periods of large tidal stress. Here we calculate the tidal stress history, and specifically the amplitude of tidal stress, on a fault plane in the two weeks before large earthquakes globally, based on data from the global, Japanese, and Californian earthquake catalogues. We find that very large earthquakes, including the 2004 Sumatran, 2010 Maule earthquake in Chile and the 2011 Tohoku-Oki earthquake in Japan, tend to occur near the time of maximum tidal stress amplitude. This tendency is not obvious for small earthquakes. However, we also find that the fraction of large earthquakes increases (the b-value of the Gutenberg-Richter relation decreases) as the amplitude of tidal shear stress increases. The relationship is also reasonable, considering the well-known relationship between stress and the b-value. This suggests that the probability of a tiny rock failure expanding to a gigantic rupture increases with increasing tidal stress levels. We conclude that large earthquakes are more probable during periods of high tidal stress.

  4. Collecting Rocks

    Institute of Scientific and Technical Information of China (English)

    孙铮

    2007-01-01

    My hobby is collecting rocks.It is very special,isn’t it?I began to collect rocks about four years ago.I usually go hiking in the mountains,or near the river to look for rocks.When I find a rock,I pick it up and clean it with the brush and water.Then I put it into my bag.Most of the rocks I have collected are quartzite~*.They are really

  5. An investigation of Laser Induced Breakdown Spectroscopy for use as a control in the laser removal of rock from fossils found at the Malapa hominin site, South Africa

    CSIR Research Space (South Africa)

    Roberts, DE

    2012-07-01

    Full Text Available Laser Induced Breakdown Spectroscopy (LIBS) was used to study the spectra from fossils and surrounding rock recovered from the Cradle of Mankind site at Malapa, South Africa. The objective was to find a suitable spectral line(s), specific to fossils...

  6. Earthquake Hazards Program: Earthquake Scenarios

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A scenario represents one realization of a potential future earthquake by assuming a particular magnitude, location, and fault-rupture geometry and estimating...

  7. Intensive Observation of Reservoirinduced Seismicity and Preliminary Analysis on the Causes of Earthquakes in the Three Gorges Reservoir Area, Yangtze River

    Institute of Scientific and Technical Information of China (English)

    Ma Wentao; Xu Changpeng; Yuan Jingli; Li Hai'ou; Xu Xiwei; Zhang Xindong; Zhang Lanfeng

    2011-01-01

    the areas west of Xietan, Shazhen and Xizhen, may be related to the softening of discontinuities, such as the Nukou fault, the Xiannvshan fault, or the bedding joints, which would lead to failure of rock masses, thus, inducing earthquakes. However, convincing conclusions about the triggering mechanism still need further study. Additionally, near the areas south of Wenhua and Yanglin of Zigui county and at Rangkou town east of Badong county, mininginduced earthquakes occurred at the mines nearby, and on the shores of the reservoir are some collapse earthquakes.

  8. 汶川地震灾害移民生计状况变化%Living Situation of Hazard-induced Migration after Wenchuan Earthquake Disaster

    Institute of Scientific and Technical Information of China (English)

    贺莉; 付少平

    2015-01-01

    Change in living status of hazard-induced migration was analyzed by the established calculation system of living capital based on the theoretical framework of sustainable living of relocated hazard-induced migration after Wenchuan earthquake disaster to provide a reference for sustainable living of hazard-induced migration.The results show that labor capital,natural capital and social capital of hazard-induced migration decreases,financial capital and physical capital increase greatly,which result in promotion of living capital' integral level compared with hazard-induced migration before Wenchuan earthquake disaster.The sustainable living of hazard-induced migration can be further improved from four aspects of settlement policy,industrial development planning,skill training and employment environment.%为促进灾害移民的可持续生计提供参考,以汶川地震后异地安置的移民为例,基于可持续生计的理论框架,构建生计资本测算体系,对其生计状况变化进行了分析。结果表明:与地震前相比,灾害移民的人力资本、自然资本和社会资本减少,金融资本与物质资本大幅增加,生计资本整体水平有所提升。应从安置政策、产业发展规划、技能培训、就业环境等方面着手,进一步促进灾害移民的可持续生计。

  9. Improving the location of induced earthquakes associated with an underground gas storage in the Gulf of Valencia (Spain)

    Science.gov (United States)

    Gaite, Beatriz; Ugalde, Arantza; Villaseñor, Antonio; Blanch, Estefania

    2016-05-01

    On September 2013, increased seismic activity was recorded near the CASTOR offshore underground gas storage (UGS), in the Gulf of Valencia (Spain). According to the reports by the Spanish Instituto Geográfico Nacional (IGN), more than 550 events occurred during two months, the strongest having a magnitude of Mw = 4.2 which took place two weeks after the gas injection stopped. The low magnitude of the events (with only 17 earthquakes having mbLg greater than 3), the lack of nearby stations, and the inhomogeneous station distribution made the location problem a great challenge. Here we present improved locations for a subset of 161 well recorded events from the earthquake sequence using a probabilistic nonlinear earthquake location method. A new 3-D shear-wave velocity model is also estimated in this work from surface-wave ambient noise tomography. To further improve the locations, waveform cross-correlations are computed at each station for every event pair and new locations are obtained from an inverted set of adjusted travel time picks. The resulting hypocentral solutions show a tighter clustering with respect to the initial locations and they are distributed in a NW-SE direction. Most of the earthquakes are located near the injection well at depths of about 6 km. Our results indicate that the observed seismicity is closely associated with the injection activities at the CASTOR underground gas storage and may have resulted from the reactivation of pre-existing unmapped faults, located a few kilometers below the reservoir.

  10. Physical Mechanisms for Earthquakes at Intermediate Depths

    Science.gov (United States)

    Green, H. W.; Green, H. W.

    2001-12-01

    Conventional brittle shear failure it is strongly inhibited by pressure because it relies on local tensile failure. In contrast, plastic flow processes are thermally activated, making them sensitive functions of temperature, but their pressure dependence is only moderate. As a consequence, in Earth, faulting by unassisted brittle failure is probably restricted to depths less than ~ 30 km because the rocks flow at lower stresses than they fracture. To enable faulting at greater depths, mineral reactions must occur that generate a fluid or fluid-like solid that is much weaker than the parent assemblage. Although a variety of plastic instabilities have been and continue to be proposed to explain earthquakes at depth, dehydration embrittlement remains the only experimentally verified faulting mechanism consistent with the pressures and compositions existing at depths of 50-300km within subducting lithosphere. However, low pressure hydrous phases potentially abundant in subducting lithosphere (e.g. chlorite and antigorite) exhibit a temperature maximum in their stability, implying that the bulk volume change at depths of more than 70-100 km. becomes negative, thereby raising questions about mechanical instability upon dehydration. Further, it is now well-accepted that intermediate-depth earthquakes occur within the descending slab (double seismic zones present in several slabs dramatically demonstrate this fact), in conflict with the maximum depth of 10-12 km accepted for hydration of the lithosphere at oceanic spreading centers. Thus, on the one hand these earthquakes may be evidence that hydrous phases exist deep within subducting slabs but on the other hand, a mechanism for hydration to such depths is not known. One possibility is that large earthquakes outboard of trenches break the surface and allow hydration of the fault zone that can later dehydrate to yield earthquakes at depth, but no mechanism is known for pumping H2O into such fault zones to depths of tens of

  11. Observation of ionospheric gravity waves induced by the 2011 Tohoku earthquake and tsunami using GPS networks in Japan

    Science.gov (United States)

    Tang, Long; Guo, Bofeng; Zhang, Xiaohong

    2017-04-01

    Recent observation results show the atmospheric gravity waves produced by both tsunami and earthquake can propagate upward to the atmosphere and interact with the plasma at the ionospheric height, leading to the generation of ionospheric disturbances. Carefully analyzing the propagation characteristics of ionospheric disturbances is necessary in order to distinguish the sources. Here, we use the GPS total electron content (TEC) observations in Japan to detect the ionospheric disturbances after the 2011 Tohoku earthquake, respectively. The Tohoku (Japan) earthquake (Mw=9) occurred at 05:46 UT on 11 March 2011 and then triggered powerful tsunami. The fundamental work is to properly isolate the ionospheric disturbances from raw TEC observations. Here, a second-order number difference method is employed to extract disturbance series and analyze the propagation characteristics of the ionospheric disturbances. The results show there are two types of gravity waves in the ionosphere over Japan, which is produced by the tsunami waves and the seismic rupture process, respectively. The earthquake-driven ionospheric gravity waves are distributed around the epicenter (including the areas over and far from the ocean) whereas the tsunami-driven ionospheric gravity waves are observed above the ocean. The earthquake-driven ionospheric gravity waves have different horizontal velocities, including about 210 m/s and 170 m/s, and frequency of about 1.5 mHz. The tsunami-driven ionospheric gravity waves have velocity of about 280 m/s, which are faster than that of the earthquake-driven ionospheric gravity waves, and frequency of about 1.0 mHz. In addition, the tsunami-driven ionospheric gravity waves have similar propagation characteristics in terms of horizontal velocity, direction, travel time, waveform and frequency compared to the tsunami waves causing them. In short, this study distinguishes the tsunami signals in ionosphere from ionospheric disturbances triggered by the earthquake

  12. From stones to rocks

    Science.gov (United States)

    Mortier, Marie-Astrid; Jean-Leroux, Kathleen; Cirio, Raymond

    2013-04-01

    With the Aquila earthquake in 2009, earthquake prediction is more and more necessary nowadays, and people are waiting for even more accurate data. Earthquake accuracy has increased in recent times mainly thanks to the understanding of how oceanic expansion works and significant development of numerical seismic prediction models. Despite the improvements, the location and the magnitude can't be as accurate as citizen and authorities would like. The basis of anticipating earthquakes requires the understanding of: - The composition of the earth, - The structure of the earth, - The relations and movements between the different parts of the surface of the earth. In order to answer these questions, the Alps are an interesting field for students. This study combines natural curiosity about understanding the predictable part of natural hazard in geology and scientific skills on site: observing and drawing landscape, choosing and reading a representative core drilling, replacing the facts chronologically and considering the age, the length of time and the strength needed. This experience requires students to have an approach of time and space radically different than the one they can consider in a classroom. It also limits their imagination, in a positive way, because they realize that prediction is based on real data and some of former theories have become present paradigms thanks to geologists. On each location the analyzed data include landscape, core drilling and the relation established between them by students. The data is used by the students to understand the meaning, so that the history of the formation of the rocks tells by the rocks can be explained. Until this year, the CBGA's perspective regarding the study of the Alps ground allowed students to build the story of the creation and disappearance of the ocean, which was a concept required by French educational authorities. But not long ago, the authorities changed their scientific expectations. To meet the

  13. Correlation of Coseismic Velocity and Static Volumetric Strain Changes Induced by the 2010 Mw6.3 Jiasian Earthquake under the Southern Taiwan Orogenic Belt

    Science.gov (United States)

    Wu, S. M.; Hung, S. H.

    2015-12-01

    Earthquake-induced temporal changes in seismic velocity of the earth's crust have been demonstrated to be monitored effectively by the time-lapse shifts of coda waves recently. Velocity drop during the coseismic rupture has been explicitly observed in proximity to the epicenters of large earthquakes with different styles of faulting. The origin of such sudden perturbation in crustal properties is closely related to the damage and/or volumetric strain change influenced by seismic slip distribution. In this study, we apply a coda wave interferometry method to investigate potential velocity change in both space and time related to the moderate-sized (Mw6.3) 2010 Jiasian earthquake, which nucleated deeply in the crust (~23 km), ruptured and terminated around the depth of 10 km along a previously unidentified blind thrust fault near the lithotectonic boundary of the southern Taiwan orogenic belt. To decipher the surface and crustal response to this relatively deep rupture, we first measure relative time-lapse changes of coda between different short-term time frames spanning one year covering the pre- and post-seismic stages by using the Moving Window Cross Spectral Method. Rather than determining temporal velocity variations based on a long-term reference stack, we conduct a Bayesian least-squares inversion to obtain the optimal estimates by minimizing the inconsistency between the relative time-lapse shifts of individual short-term stacks. The results show the statistically significant velocity reduction immediately after the mainshock, which is most pronounced at the pairs with the interstation paths traversing through the hanging-wall block of the ruptured fault. The sensitivity of surface wave coda arrivals mainly in the periods of 3-5 s to shear wave speed perturbation is confined within the depth of 10 km, where the crust mostly experienced extensional strain changes induced by the slip distribution from the finite-fault model. Compared with coseismic slip

  14. Earthquake-induced liquefaction features in the coastal setting of South Carolina and in the fluvial setting of the New Madrid seismic zone

    Science.gov (United States)

    Obermeier, S.F.; Jacobson, R.B.; Smoot, J.P.; Weems, R.E.; Gohn, G.S.; Monroe, J.E.; Powars, D.S.

    1990-01-01

    Many types of liquefaction-related features (sand blows, fissures, lateral spreads, dikes, and sills) have been induced by earthquakes in coastal South Carolina and in the New Madrid seismic zone in the Central United States. In addition, abundant features of unknown and nonseismic origin are present. Geologic criteria for interpreting an earthquake origin in these areas are illustrated in practical applications; these criteria can be used to determine the origin of liquefaction features in many other geographic and geologic settings. In both coastal South Carolina and the New Madrid seismic zone, the earthquake-induced liquefaction features generally originated in clean sand deposits that contain no or few intercalated silt or clay-rich strata. The local geologic setting is a major influence on both development and surface expression of sand blows. Major factors controlling sand-blow formation include the thickness and physical properties of the deposits above the source sands, and these relationships are illustrated by comparing sand blows found in coastal South Carolina (in marine deposits) with sand blows found in the New Madrid seismic zone (in fluvial deposits). In coastal South Carolina, the surface stratum is typically a thin (about 1 m) soil that is weakly cemented with humate, and the sand blows are expressed as craters surrounded by a thin sheet of sand; in the New Madrid seismic zone the surface stratum generally is a clay-rich deposit ranging in thickness from 2 to 10 m, in which case sand blows characteristically are expressed as sand mounded above the original ground surface. Recognition of the various features described in this paper, and identification of the most probable origin for each, provides a set of important tools for understanding paleoseismicity in areas such as the Central and Eastern United States where faults are not exposed for study and strong seismic activity is infrequent.

  15. Earthquake Breccias (Invited)

    Science.gov (United States)

    Rowe, C. D.; Melosh, B. L.; Lamothe, K.; Schnitzer, V.; Bate, C.

    2013-12-01

    Fault breccias are one of the fundamental classes of fault rocks and are observed in many exhumed faults. Some breccias have long been assumed to form co-seismically, but textural or mechanistic evidence for the association with earthquakes has never been documented. For example, at dilational jogs in brittle faults, it is common to find small bodies of chaotic breccia in lenticular or rhombohedral voids bounded by main slip surfaces and linking segments. Sibson interpreted these 'implosion breccias' as evidence of wall rock fracturing during sudden unloading when the dilational jogs open during earthquake slip (Sibson 1985, PAGEOPH v. 124, n. 1, 159-175). However, the role of dynamic fracturing in forming these breccias has not been tested. Moreover, the criteria for identifying implosion breccia have not been defined - do all breccias in dilational jogs or step-overs represent earthquake slip? We are building a database of breccia and microbreccia textures to develop a strictly observational set of criteria for distinction of breccia texture classes. Here, we present observations from the right-lateral Pofadder Shear Zone, South Africa, and use our textural criteria to identify the relative roles of dynamic and quasi-static fracture patterns, comminution/grinding and attrition, hydrothermal alteration, dissolution, and cementation. Nearly 100% exposure in the hyper-arid region south of the Orange River allowed very detailed mapping of frictional fault traces associated with rupture events, containing one or more right-steps in each rupture trace. Fracture patterns characteristic of on- and off-fault damage associated with propagation of dynamic rupture are observed along straight segments of the faults. The wall rock fractures are regularly spaced, begin at the fault trace and propagate at a high angle to the fault, and locally branch into subsidiary fractures before terminating a few cm away. This pattern of fractures has been previously linked to dynamic

  16. p38MAPK, Rho/ROCK and PKC pathways are involved in influenza-induced cytoskeletal rearrangement and hyperpermeability in PMVEC via phosphorylating ERM.

    Science.gov (United States)

    Zhang, Chenyue; Wu, Ying; Xuan, Zinan; Zhang, Shujing; Wang, Xudan; Hao, Yu; Wu, Jun; Zhang, Shu

    2014-11-04

    Severe influenza infections are featured by acute lung injury, a syndrome of pulmonary microvascular leak. A growing number of evidences have shown that the pulmonary microvascular endothelial cells (PMVEC) are critical target of influenza virus, promoting microvascular leak. It is reported that there are multiple mechanisms by which influenza virus could elicit increased pulmonary endothelial permeability, in both direct and indirect manners. Ezrin/radixin/moesin family proteins, the linkers between plasma membrane and actin cytoskeleton, have been reported to be involved in cell adhesion, motility and may modulate endothelial permeability. Studies have also shown that ERM is phosphorylated in response to various stimuli via p38MAPK, Rho/ROCK or PKC pathways. However, it is unclear that whether influenza infection could induce ERM phosphorylation and its relocalization. In the present study, we have found that there are cytoskeletal reorganization and permeability increases in the course of influenza virus infection, accompanied by upregulated levels of p-ERM. p-ERM's aggregation along the periphery of PMVEC upon influenza virus infection was detected via confocal microscopy. Furthermore, we sought to determine the role of p38MAPK, Rho/ROCK and PKC pathways in ERM phosphorylation as well as their involvement in influenza virus-induced endothelial malfunction. The activation of p38MAPK, Rho/ROCK and PKC pathways upon influenza virus stimulation were observed, as evidenced by the evaluation of phosphorylated p38 (p-p38), phosphorylated MKK (p-MKK) in p38MAPK pathway, ROCK1 in Rho/ROCK pathway and phosphorylated PKC (p-PKC) in PKC pathway. We also showed that virus-induced ERM phosphorylation was reduced by using p38MAPK inhibitor, SB203580 (20 μM), Rho/ROCK inhibitor, Y27632 (20 μM), PKC inhibitor, LY317615 (10 μM). Additionally, influenza virus-induced F-actin reorganization and hyperpermeability were attenuated by pretreatment with SB203580, Y27632 and LY317615

  17. Are Earthquakes Predictable? A Study on Magnitude Correlations in Earthquake Catalog and Experimental Data

    Science.gov (United States)

    Stavrianaki, K.; Ross, G.; Sammonds, P. R.

    2015-12-01

    The clustering of earthquakes in time and space is widely accepted, however the existence of correlations in earthquake magnitudes is more questionable. In standard models of seismic activity, it is usually assumed that magnitudes are independent and therefore in principle unpredictable. Our work seeks to test this assumption by analysing magnitude correlation between earthquakes and their aftershocks. To separate mainshocks from aftershocks, we perform stochastic declustering based on the widely used Epidemic Type Aftershock Sequence (ETAS) model, which allows us to then compare the average magnitudes of aftershock sequences to that of their mainshock. The results of earthquake magnitude correlations were compared with acoustic emissions (AE) from laboratory analog experiments, as fracturing generates both AE at the laboratory scale and earthquakes on a crustal scale. Constant stress and constant strain rate experiments were done on Darley Dale sandstone under confining pressure to simulate depth of burial. Microcracking activity inside the rock volume was analyzed by the AE technique as a proxy for earthquakes. Applying the ETAS model to experimental data allowed us to validate our results and provide for the first time a holistic view on the correlation of earthquake magnitudes. Additionally we search the relationship between the conditional intensity estimates of the ETAS model and the earthquake magnitudes. A positive relation would suggest the existence of magnitude correlations. The aim of this study is to observe any trends of dependency between the magnitudes of aftershock earthquakes and the earthquakes that trigger them.

  18. Changes of ecological conditions induced by rock tunneling in Laoshan Mountain area

    Institute of Scientific and Technical Information of China (English)

    Xiaozhao LI; Xiaobao ZHAO; Zhongsheng WANG

    2008-01-01

    Through field investigation, this paper exam-ined the changes of ecological conditions induced by tun-nel construction in Laoshan Mountain area, Nanjing, Jiangsu Province, P. R. China. The effects of habitat frag-mentation and edge effect are examined and discussed. It is found that the environmental factors and vegetation situation have been influenced by the tunneling activity, and the disturbed area is approaching the sampling patch centre. The changed ecological conditions are beneficial for the settlement and growth of some herb and shrub species, and are unfavorable for the existence and growth of saplings, especially for the predominant species (e.g., robur) in this area. If the time of habitat fragmentation is long enough and there is no supplement from external areas, some vegetation species in the engineering influ-encing area will deteriorate, or even diminish in the future. The results can be used as a reference for the long-term ecological study in this area.

  19. Estimating soil erosion changes in the Wenchuan earthquake disaster area using geo-spatial information technology

    Science.gov (United States)

    Zhang, Bing; Jiao, Quanjun; Wu, Yanhong; Zhang, Wenjuan

    2009-05-01

    The secondary disasters induced by the Wenchuan earthquake of May 12, 2008, such as landslides, collapsing rocks, debris flows, floods, etc., have changed the local natural landscape tremendously and caused heavy soil erosion in the earthquake-hit areas. Using thematic mapper images taken before the earthquake and airborne images taken after the earthquake, we extracted information about the destroyed landscape by utilizing remote sensing and geographical information system techniques. Then, taking into account multi-year precipitation, vegetation cover, soil type, land use, and elevation data, we evaluated the soil erosion area and intensity using the revised universal soil loss equation. Results indicate that the soil erosion in earthquake-hit areas was exacerbated, with the severe erosion area increasing by 279.2 km2, or 1.9% of the total statistical area. Large amounts of soil and debris blocked streams and formed many barrier lakes over an area of more than 3.9 km2. It was evident from the spatial distribution of soil erosion areas that the intensity of soil erosion accelerated in the stream valley areas, especially in the valleys of the Min River and the Jian River.

  20. Rock Stars

    Institute of Scientific and Technical Information of China (English)

    张国平

    2000-01-01

    Around the world young people are spending unbelievable sums of money to listen to rock music. Forbes Magazine reports that at least fifty rock stars have incomes between two million and six million dollars per year.

  1. KREEP Rocks

    Institute of Scientific and Technical Information of China (English)

    邹永廖; 徐琳; 欧阳自远

    2004-01-01

    KREEP rocks with high contents of K, REE and P were first recognized in Apollo-12 samples, and it was confirmed later that there were KREEP rock fragments in all of the Apollo samples, particularly in Apollo-12 and-14 samples. The KREEP rocks distributed on the lunar surface are the very important objects of study on the evolution of the moon, as well as to evaluate the utilization prospect of REE in KREEP rocks. Based on previous studies and lunar exploration data, the authors analyzed the chemical and mineral characteristics of KREEP rocks, the abundance of Th on the lunar surface materials, the correlation between Th and REE of KREEP rocks in abundance, studied the distribution regions of KREEP rocks on the lunar surface, and further evaluated the utilization prospect of REE in KREEP rocks.

  2. 四川安县地震灾区洪水沟泥石流特征及防治工程设计%FEATURES OF FLOOD-DITCH MUD-ROCK FLOW AND THE DESIGN OF PREVENTIVE AND TREATMENT WORKS IN THE EARTHQUAKE-HIT AREA OF AN COUNTY,SICHUAN

    Institute of Scientific and Technical Information of China (English)

    储长付; 胡凌

    2012-01-01

    四川"5.12"大地震,严重的破坏力当地的地质环境,诱发多处地质灾害。本文对地震灾区洪水沟泥石流形成机理、分布状况及性质特征进行了分析研究,实测和估算出固体物源动储量,详细计算了泥石流流体性质参数。进行了防治工程设计计算。结合工程实例及实践经验,提出了泥石流防治工程设计要点。%The Sichuan "5.12"great earthquake seriously damaged local geological environment and brought about many places of geological hazards.This paper analyzed formation mechanism,distribution,natures and features of flood-ditch mud-rock flows in the earthquake-hit areas,measured and estimated reserve of solid material source,made a calculation in detail of nature parameter of mud-rock flow,conducted design calculation for rpeventive and treatment works,and finally put forward the key points in design based on example works and experience.

  3. RhoA/ROCK pathway mediates leptin-induced uPA expression to promote cell invasion in ovarian cancer cells.

    Science.gov (United States)

    Ghasemi, Ahmad; Hashemy, Seyed Isaac; Aghaei, Mahmoud; Panjehpour, Mojtaba

    2017-04-01

    Previous studies have shown that leptin, an adipocyte-secreted hormone, stimulates ovarian cancer invasion. Here, we investigated the contribution of uPA in leptin-induced ovarian cancer cell invasion. The cell invasion and migration experiments were carried out using matrigel invasion and wound healing assays in ovarian cancer cell lines (OVCAR3, SKOV3and CaoV-3). The mechanism underlying the invasive effect of leptin was examined using cell transfection with Ob-Rb siRNA, pre-treatment with a specific inhibitor of RhoA and ROCK, RhoA activation assay, OB-Rb, Rock and upA protein expression. Our results show that leptin induced ovarian cancer cell invasion via up-regulating upA in a time and dose-dependent manner, which was attenuated using knockdown of OB-Rb by siRNA. Moreover, pre-incubation with C3 (inhibitor of RhoA) and Y-27632 (inhibitor of ROCK) effectively attenuated leptin-induced upA expression and inhibited invasive ability of ovarian cancer cells. We also found that pretreatment with inhibitors of PI3K/AKT (LY294002), JAK/STAT (AG490) and NF-kB (BAY 11-7082) significantly reduced leptin-induced upA expression. Collectively, our findings demonstrate that OB-Rb, RhoA/ROCK, PI3K/AKT, JAK/STAT pathways and NF-kB activation are involved in leptin-induced upA expression. These results may provide a new mechanism that facilitates leptin-induced ovarian cancer invasion.

  4. An investigation of Laser Induced Breakdown Spectroscopy for use as a control in the laser removal of rock from fossils found at the Malapa hominin site, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D.E., E-mail: troberts@csir.co.za [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Plessis, A. du [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); University of Stellenbosch, Private Bag X1, Matieland, Stellenbosch (South Africa); Steyn, J.; Botha, L.R.; Pityana, S. [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Berger, L.R. [Institute for Human Evolution, School of GeoSciences, University of Witwatersrand, Private Bag 3, Wits 2050 (South Africa)

    2012-07-15

    Laser Induced Breakdown Spectroscopy (LIBS) was used to study the spectra from fossils and surrounding rock recovered from the Cradle of Mankind site at Malapa, South Africa. The objective was to find a suitable spectral line(s), specific to fossils, which could be used as a control signal to limit damage to fossils during high speed laser removal of the encasing rock. The calcified clastic matrix (rock) encasing the fossils was found to emit a variety of complex LIBS spectra. Nevertheless, it was found possible to distinguish fossils in a single LIBS pulse, and without significant damage to the fossil, using spectral lines of neutral phosphorus. - Highlights: Black-Right-Pointing-Pointer LIBS used to discriminate fossils from rock as potential processing control mechanism. Black-Right-Pointing-Pointer 2 million year old fossils from Malapa hominin site found to be high in phosphorus. Black-Right-Pointing-Pointer Rock spectral lines from silicon, iron and manganese, but no phosphorus. Black-Right-Pointing-Pointer Holds great promise for process control in laser preparation of fossils. Black-Right-Pointing-Pointer Also promising for accurate identification of fossils at excavation sites.

  5. Study on Kinematic Velocity of High-speed and Long-range Landslides Induced by Wenchuan Earthquake%汶川地震高速远程滑坡速度研究

    Institute of Scientific and Technical Information of China (English)

    方华; 裴来政; 向灵芝

    2011-01-01

    The Wenchuan earthquake triggered lots of high-speed and long-range landslides, and under the super-strong ground motions,the slope was easily torn and ejected,then the sliding mass was crashed and transferred into debris flow for long-range movement because of the terrain and its potential energy. This type of rock-fragment flow had great kinematic velocity and extraordinary running out distance which caused great disasters and losses to the stricken region people. Based on lots of field investigations of large-scale typical high-speed and long-range landslides induced by the Wenchuan earthquake, this paper summarizes and analyzes the initial flight velocity, maximum kinematic velocity and debris flow velocity,comparatively calculates the movement velocity and motility of Donghekou landslide by different simplified methods. Results show that the movement characteristic value of Donghekou landslide is 0. 2292,maximum kinematic velocity is 63.40 m/s, and average velocity exceeds 25 m/s, which belongs to superhigh speed landslide and has strong debris flow characteristics.%汶川地震诱发了大量的高速远程滑坡.在超强的地震动作用下,坡体结构被撕裂并抛射后,受到坡体前缘地形及自身势能的影响,很容易转化为碎屑流作远程运动,这种高位滑坡以其很快的运动速度和超常的运动距离造成了巨大的灾害与损失.本文在对汶川地震大型典型高速远程滑坡大量现场调查的基础上,分析了坡体临空飞行运动初始速度、滑程运动最大速度以及碎屑流运动速度,并且以东河口滑坡为例,对比了不同计算方法下的运动速度和运动性,得到东河口滑坡的运动特征值μ=0.2292,最大运动速度Vmax=63.40m/s,平均运动速度超过25 m/s,属于超高速滑坡运动以及强碎屑流性质.

  6. Rock Art

    Science.gov (United States)

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  7. Rock Art

    Science.gov (United States)

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  8. Rock Finding

    Science.gov (United States)

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  9. Arsenic-induced plant growth of arsenic-hyperaccumulator Pteris vittata: Impact of arsenic and phosphate rock.

    Science.gov (United States)

    Han, Yong-He; Yang, Guang-Mei; Fu, Jing-Wei; Guan, Dong-Xing; Chen, Yanshan; Ma, Lena Q

    2016-04-01

    Phosphate rock (PR) has been shown to promote plant growth and arsenic (As) uptake by As-hyperaccumulator Pteris vittata (PV). However, little is known about its behaviors in agricultural soils. In this study, impact of 50 mg kg(-1) As and/or 1.5% PR amendment on plant As accumulation and growth was investigated by growing PV for 90 d in three agricultural soils. While As amendment significantly increased plant As uptake and substantially promoted PV growth, the opposite was observed with PR amendment. Arsenic amendment increased plant frond As from 16.9-265 to 961-6017 mg kg(-1),whereas PR amendment lowered frond As to 10.2-216 mg kg(-1). The As-induced plant growth stimulation was 69-71%. While PR amendment increased plant Ca and P uptake, As amendment showed opposite results. The PV biomass was highly correlated with plant As at r = 0.82, but with weak correlations with plant Ca or P at r < 0.30. This study confirmed that 1) As significantly promoted PV growth, probably independent of Ca or P uptake, 2) PR amendment didn't enhance plant growth or As uptake by PV in agricultural soils with adequate available P, and 3) PV effluxed arsenite (AsIII) growing in agricultural soils.

  10. Water-rock interaction induced by contaminated groundwater in a karst aquifer, Greece

    Science.gov (United States)

    Panagopoulos, G.; Lambrakis, N.; Katagas, C.; Papoulis, D.; Tsolis-Katagas, P.

    2005-12-01

    The karst system of SW Trifilia is composed of a thick sequence of carbonate sediments, which have experienced two types of dolomitization and dedolomitization processes and comprise an extended aquifer. The application of fertilizers in the region have not only caused the degradation of the groundwater quality but also induced hydrochemical changes exerting major control on dolomitization processes. Factor analysis indicates high correlation coefficient between NH{4/+}, NO{3/-}, Ca2+ and Mg2+, which can be attributed to cation-exchange processes involving clay minerals. The application of a conservative mixing model showed that the calculated groundwater types indicate a cation-exchange process between NH{4/+}, derived from fertilizers, and between Ca2+ and Mg2+. Mg2+ released from smectite interlayers, exchanged for NH{4/+} in the groundwater and favor a dolomitization process through the partial replacement of Ca2+ in the lattice of calcite (dedolomite) contained in precursor dolomites. This recent stage dolomitization occurred near the water level and within the phreatic zone only and had not influenced the whole karst massif; it also resulted in low Mg/Ca values found in the zone characterized by intensive application of nitrogen-based fertilizers and the absence of overlying impermeable strata.

  11. Earthquake Damage Assessment Using Objective Image Segmentation: A Case Study of 2010 Haiti Earthquake

    Science.gov (United States)

    Oommen, Thomas; Rebbapragada, Umaa; Cerminaro, Daniel

    2012-01-01

    In this study, we perform a case study on imagery from the Haiti earthquake that evaluates a novel object-based approach for characterizing earthquake induced surface effects of liquefaction against a traditional pixel based change technique. Our technique, which combines object-oriented change detection with discriminant/categorical functions, shows the power of distinguishing earthquake-induced surface effects from changes in buildings using the object properties concavity, convexity, orthogonality and rectangularity. Our results suggest that object-based analysis holds promise in automatically extracting earthquake-induced damages from high-resolution aerial/satellite imagery.

  12. Earthquake Damage Assessment Using Objective Image Segmentation: A Case Study of 2010 Haiti Earthquake

    Science.gov (United States)

    Oommen, Thomas; Rebbapragada, Umaa; Cerminaro, Daniel

    2012-01-01

    In this study, we perform a case study on imagery from the Haiti earthquake that evaluates a novel object-based approach for characterizing earthquake induced surface effects of liquefaction against a traditional pixel based change technique. Our technique, which combines object-oriented change detection with discriminant/categorical functions, shows the power of distinguishing earthquake-induced surface effects from changes in buildings using the object properties concavity, convexity, orthogonality and rectangularity. Our results suggest that object-based analysis holds promise in automatically extracting earthquake-induced damages from high-resolution aerial/satellite imagery.

  13. Effect of the rock properties on mining-induced seismicity around the Ventersdorp contact reef, Witwatersrand basin, South Africa

    CSIR Research Space (South Africa)

    Milev, AM

    2002-01-01

    Full Text Available The Ventersdorp Contact Reef is characterised by a variety of different rock types that are found above and below the reef in different mining areas. These variations in the host rock type have been classified into six main geotechnical areas...

  14. Instrumental shaking thresholds for seismically induced landslides and preliminary report on landslides triggered by the October 17, 1989, Loma Prieta, California earthquake

    Science.gov (United States)

    Harp, E.L.

    1993-01-01

    The generation of seismically induced landslide depends on the characteristics of shaking as well as mechanical properties of geologic materials. A very important parameter in the study of seismically induced landslide is the intensity based on a strong-motion accelerogram: it is defined as Arias intensity and is proportional to the duration of the shaking record as well as the amplitude. Having a theoretical relationship between Arias intensity, magnitude and distance it is possible to predict how far away from the seismic source landslides are likely to occur for a given magnitude earthquake. Field investigations have established that the threshold level of Arias intensity depends also on site effects, particularly the fracture characteristics of the outcrops present. -from Author

  15. Thermally induced stresses in boulders on airless body surfaces, and implications for rock breakdown

    Science.gov (United States)

    Molaro, J. L.; Byrne, S.; Le, J.-L.

    2017-09-01

    This work investigates the macroscopic thermomechanical behavior of lunar boulders by modeling their response to diurnal thermal forcing. Our results reveal a bimodal, spatiotemporally-complex stress response. During sunrise, stresses occur in the boulders' interiors that are associated with large-scale temperature gradients developed due to overnight cooling. During sunset, stresses occur at the boulders' exteriors due to the cooling and contraction of the surface. Both kinds of stresses are on the order of 10 MPa in 1 m boulders and decrease for smaller diameters, suggesting that larger boulders break down more quickly. Boulders ≤ 30 cm exhibit a weak response to thermal forcing, suggesting a threshold below which crack propagation may not occur. Boulders of any size buried by regolith are shielded from thermal breakdown. As boulders increase in size (>1 m), stresses increase to several 10 s of MPa as the behavior of their surfaces approaches that of an infinite halfspace. As the thermal wave loses contact with the boulder interior, stresses become limited to the near-surface. This suggests that the survival time of a boulder is not only controlled by the amplitude of induced stress, but also by its diameter as compared to the diurnal skin depth. While stresses on the order of 10 MPa are enough to drive crack propagation in terrestrial environments, crack propagation rates in vacuum are not well constrained. We explore the relationship between boulder size, stress, and the direction of crack propagation, and discuss the implications for the relative breakdown rates and estimated lifetimes of boulders on airless body surfaces.

  16. Seismically Induced Slope Instabilities and the Corresponding Treatments: the Case of a Road in the Wenchuan Earthquake Hit Region

    Institute of Scientific and Technical Information of China (English)

    LI Xinpo; HE Siming

    2009-01-01

    On May 12, 2008, a magnitude 8.0 earthquake hit Wenchuan County, Sichuan Province resulted in great loss of life and properties. Besides, abundant landslides and slope failures were triggered in the most seriously hit areas and caused disastrous damages to infrastructures and public facilities. Moreover, abundant unstable slopes caused by the quake have the potential to cause damages for a considerable long period of time. The variety of these slopes and the corresponding treatments are connected with the topographical and geological conditions of the sites. It is decided to document and identify some of these major slope instabilities caused by the earthquake and their treatments. The paper shows the condition of a road in Dujiangyan through in situ explorations. The case history showed significant implications to the reconstruction of the quake-hit regions and future disaster prevention and management works.

  17. Vascular smooth muscle cell glycocalyx mediates shear stress-induced contractile responses via a Rho kinase (ROCK)-myosin light chain phosphatase (MLCP) pathway.

    Science.gov (United States)

    Kang, Hongyan; Liu, Jiajia; Sun, Anqiang; Liu, Xiao; Fan, Yubo; Deng, Xiaoyan

    2017-02-13

    The vascular smooth muscle cells (VSMCs) are exposed to interstitial flow induced shear stress that may be sensed by the surface glycocalyx, a surface layer composed primarily of proteoglycans and glycoproteins, to mediate cell contraction during the myogenic response. We, therefore, attempted to elucidate the signal pathway of the glycocalyx mechanotransduction in shear stress regulated SMC contraction. Human umbilical vein SMCs (HUVSMCs) deprived of serum for 3-4 days were exposed to a step increase (0 to 20 dyn/cm(2)) in shear stress in a parallel plate flow chamber, and reduction in the cell area was quantified as contraction. The expressions of Rho kinase (ROCK) and its downstream signal molecules, the myosin-binding subunit of myosin phosphatase (MYPT) and the myosin light chain 2 (MLC2), were evaluated. Results showed that the exposure of HUVSMCs to shear stress for 30 min induced cell contraction significantly, which was accompanied by ROCK1 up-regulation, re-distribution, as well as MYPT1 and MLC activation. However, these shear induced phenomenon could be completely abolished by heparinase III or Y-27632 pre-treatment. These results indicate shear stress induced VSMC contraction was mediated by cell surface glycocalyx via a ROCK-MLC phosphatase (MLCP) pathway, providing evidence of the glycocalyx mechanotransduction in myogenic response.

  18. Sinomenine alleviates high glucose-induced renal glomerular endothelial hyperpermeability by inhibiting the activation of RhoA/ROCK signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Qingqiao [Renal Department of Internal Medicine, The Third Hospital of Wuhan (China); Xia, Yuanyu, E-mail: xiayuanyu.wh@gmail.com [Renal Department of Internal Medicine, The Third Hospital of Wuhan (China); Wang, Guan [Department of Cardiology, The Second Affiliated Hospital of Guangzhou Medical University (China)

    2016-09-02

    As an early sign of diabetic cardiovascular disease, endothelial dysfunction may contribute to progressive diabetic nephropathy (DN). Endothelial hyperpermeability induced by hyperglycemia (HG) is a central pathogenesis for DN. Sinomenine (SIN) has strong anti-inflammatory and renal protective effects, following an unknown protective mechanism against HG-induced hyperpermeability. We herein explored the role of SIN in vitro in an HG-induced barrier dysfunction model in human renal glomerular endothelial cells (HRGECs). The cells were exposed to SIN and/or HG for 24 h, the permeability of which was significantly increased by HG. Moreover, junction protein occludin in the cell-cell junction area and its total expression in HRGECs were significantly decreased by HG. However, the dysfunction of tight junction and hyperpermeability of HRGECs were significantly reversed by SIN. Furthermore, SIN prevented HG-increased reactive oxygen species (ROS) by activating nuclear factor-E2-related factor 2 (Nrf2). Interestingly, activation of RhoA/ROCK induced by HG was reversed by SIN or ROCK inhibitor. HG-induced hyperpermeability was prevented by SIN. High ROS level, tight junction dysfunction and RhoA/ROCK activation were significantly attenuated with knockdown of Nrf2. Mediated by activation of Nrf2, SIN managed to significantly prevent HG-disrupted renal endothelial barrier function by suppressing the RhoA/ROCK signaling pathway through reducing ROS. We successfully identified a novel pathway via which SIN exerted antioxidative and renal protective functions, and provided a molecular basis for potential SIN applications in treating DN vascular disorders.

  19. Sinomenine alleviates high glucose-induced renal glomerular endothelial hyperpermeability by inhibiting the activation of RhoA/ROCK signaling pathway.

    Science.gov (United States)

    Yin, Qingqiao; Xia, Yuanyu; Wang, Guan

    2016-09-02

    As an early sign of diabetic cardiovascular disease, endothelial dysfunction may contribute to progressive diabetic nephropathy (DN). Endothelial hyperpermeability induced by hyperglycemia (HG) is a central pathogenesis for DN. Sinomenine (SIN) has strong anti-inflammatory and renal protective effects, following an unknown protective mechanism against HG-induced hyperpermeability. We herein explored the role of SIN in vitro in an HG-induced barrier dysfunction model in human renal glomerular endothelial cells (HRGECs). The cells were exposed to SIN and/or HG for 24 h, the permeability of which was significantly increased by HG. Moreover, junction protein occludin in the cell-cell junction area and its total expression in HRGECs were significantly decreased by HG. However, the dysfunction of tight junction and hyperpermeability of HRGECs were significantly reversed by SIN. Furthermore, SIN prevented HG-increased reactive oxygen species (ROS) by activating nuclear factor-E2-related factor 2 (Nrf2). Interestingly, activation of RhoA/ROCK induced by HG was reversed by SIN or ROCK inhibitor. HG-induced hyperpermeability was prevented by SIN. High ROS level, tight junction dysfunction and RhoA/ROCK activation were significantly attenuated with knockdown of Nrf2. Mediated by activation of Nrf2, SIN managed to significantly prevent HG-disrupted renal endothelial barrier function by suppressing the RhoA/ROCK signaling pathway through reducing ROS. We successfully identified a novel pathway via which SIN exerted antioxidative and renal protective functions, and provided a molecular basis for potential SIN applications in treating DN vascular disorders.

  20. Earthquake engineering research: 1982

    Science.gov (United States)

    The Committee on Earthquake Engineering Research addressed two questions: What progress has research produced in earthquake engineering and which elements of the problem should future earthquake engineering pursue. It examined and reported in separate chapters of the report: Applications of Past Research, Assessment of Earthquake Hazard, Earthquake Ground Motion, Soil Mechanics and Earth Structures, Analytical and Experimental Structural Dynamics, Earthquake Design of Structures, Seismic Interaction of Structures and Fluids, Social and Economic Aspects, Earthquake Engineering Education, Research in Japan.

  1. An Active Blind Fault beneath the Taipei 101: Earthquakes Induced by the Vertical Loading of the Skyscraper?

    Science.gov (United States)

    Lin, C.

    2005-12-01

    Seismic activity began to slightly increase during the construction but rose sharply upon the completion of the tallest building in the world, the Taipei 101, which stands at 508 m in the Taipei basin, where local seismicity had historically very low. Besides an increase in both seismic energy and the number of micro-earthquakes, two felt earthquakes (ML=3.8 and 3.2) astonishingly occurred beneath the completed building. The focal mechanism of the larger felt earthquake and its aftershocks are indicative of an active blind normal fault just beneath the building. Estimations of the vertical loading of the Taipei 101 show that local stress on its foundation increased at least 0.47 bar, making it seem likely that the increased seismicity was a direct product of the loading of the mega-structure. Further investigations in unison with continuous seismic monitoring must be conducted because the safety of the high-rise building in the Taipei basin be comprehensively assessed.

  2. Physically-based modelling of the competition between surface uplift and erosion caused by earthquakes and earthquake sequences.

    Science.gov (United States)

    Hovius, Niels; Marc, Odin; Meunier, Patrick

    2016-04-01

    Large earthquakes deform Earth's surface and drive topographic growth in the frontal zones of mountain belts. They also induce widespread mass wasting, reducing relief. Preliminary studies have proposed that above a critical magnitude earthquake would induce more erosion than uplift. Other parameters such as fault geometry or earthquake depth were not considered yet. A new seismologically consistent model of earthquake induced landsliding allow us to explore the importance of parameters such as earthquake depth and landscape steepness. We have compared these eroded volume prediction with co-seismic surface uplift computed with Okada's deformation theory. We found that the earthquake depth and landscape steepness to be the most important parameters compared to the fault geometry (dip and rake). In contrast with previous studies we found that largest earthquakes will always be constructive and that only intermediate size earthquake (Mw ~7) may be destructive. Moreover, with landscapes insufficiently steep or earthquake sources sufficiently deep earthquakes are predicted to be always constructive, whatever their magnitude. We have explored the long term topographic contribution of earthquake sequences, with a Gutenberg Richter distribution or with a repeating, characteristic earthquake magnitude. In these models, the seismogenic layer thickness, that sets the depth range over which the series of earthquakes will distribute, replaces the individual earthquake source depth.We found that in the case of Gutenberg-Richter behavior, relevant for the Himalayan collision for example, the mass balance could remain negative up to Mw~8 for earthquakes with a sub-optimal uplift contribution (e.g., transpressive or gently-dipping earthquakes). Our results indicate that earthquakes have probably a more ambivalent role in topographic building than previously anticipated, and suggest that some fault systems may not induce average topographic growth over their locked zone during a

  3. Rock avalanches clusters along the northern Chile coastal scarp

    Science.gov (United States)

    Crosta, G. B.; Hermanns, R. L.; Dehls, J.; Lari, S.; Sepulveda, S.

    2017-07-01

    Rock avalanche clusters can be relevant indicators of the evolution of specific regions. They can be used to define: the type and intensity of triggering events, their recurrence and potential probability of occurrence, the progressive damage of the rock mass, the mechanisms of transport and deposition, as well as the environmental conditions at the time of occurrence. This paper tackles these subjects by analyzing two main clusters of rock avalanches (each event between 0.6 and 30 Mm3), separated by few kilometers and located along the coastal scarp of Northern Chile, south of Iquique. It lies, hence, within a seismic area characterized by a long seismic gap that ended on April 1st, 2014 with a Mw 8.2 earthquake. The scar position, high along the coastal cliff, supports seismic triggering for these clusters. The deposits' relative positions are used to obtain the sequence of rock avalanching events for each cluster. The progressive decrease of volume in the sequence of rock avalanches forming each cluster fits well the theoretical models for successive slope failures. These sequences seem to agree with those derived by dating the deposits with ages spanning between 4 kyr and 60 kyr. An average uplift rate of 0.2 mm/yr in the last 40 kyr is estimated for the coastal plain giving a further constraint to the rock avalanche deposition considering the absence of reworking of the deposits. Volume estimates and datings allow the estimation of an erosion rate contribution of about 0.098-0.112 mm km- 2 yr- 1 which is well comparable to values presented in the literature for earthquake induced landslides. We have carried out numerical modeling in order to analyze the mobility of the rock avalanches and examine the environmental conditions that controlled the runout. In doing so, we have considered the sequence of individual rock avalanches within the specific clusters, thus including in the models the confining effect caused by the presence of previous deposits. Bingham

  4. Numerical simulation of the 2008 West-Bohemian earthquake swarm

    Science.gov (United States)

    Heinze, Thomas; Hamidi, Sahar; Galvan, Boris; Miller, Stephen A.

    2017-01-01

    CO2 has long been suspected of driving the Bohemian earthquake swarms because of the migrating nature of the swarms and expressions of CO2 degassing at the surface. Modeling to date primarily employed linear diffusion models, but more sophisticated modeling that includes a coupled fluid - and rock mechanical model has been lacking. In this work, we apply a model that couples mechanics to heat and flow of a super-critical CO2 through a fracture network. We present a continuum mechanical approach to derive the seismic moment magnitude using the deviatoric strain as an indicator of rupturing processes during individual events. We use a peak-detection algorithm to identify rapid changes in deviatoric strain, indicative of slip events. This method has been shown to work very well in dry and fluid-induced fracturing experiments at the laboratory scale, and in this work we extend the method to the scale of the West Bohemia/Vogtland earthquake swarms. We show very good agreement between model results and observations of the 2008 swarm, further supporting the hypothesis that the Bohemian earthquake swarms are predominately fluid-driven.

  5. A custom acoustic emission monitoring system for harsh environments: application to freezing-induced damage in alpine rock-walls

    Directory of Open Access Journals (Sweden)

    L. Girard

    2012-06-01

    Full Text Available We present a custom acoustic emission (AE monitoring system designed to perform long-term measurements on high-alpine rock-walls. AE monitoring is a common technique for characterizing damage evolution in solid materials. The system is based on a two-channel AE sensor node (AE-node integrated into a Wireless Sensor Network (WSN customized for operation in harsh environments. This wireless architecture offers flexibility in the deployment of AE-nodes at any position of the rock-wall that needs to be monitored, within a range of a few hundred meters from a core station connected to the internet. The system achieves near real-time data delivery and allows the user to remotely control the AE detection threshold. In order to protect AE sensors and capture acoustic signals from specific depths of the rock-wall, a special casing was developed. The monitoring system is completed by two probes that measure rock temperature and liquid water content, both probes being also integrated into the WSN. We report a first deployment of the monitoring system on a rock-wall at Jungfraujoch, 3500 m a.s.l., Switzerland. While this first deployment of the monitoring system aims to support fundamental research on processes that damage rock under cold climate, the system could serve a number of other applications, including rock-fall hazard surveillance or structural monitoring of concrete structures.

  6. A custom acoustic emission monitoring system for harsh environments: application to freezing-induced damage in alpine rock walls

    Directory of Open Access Journals (Sweden)

    L. Girard

    2012-11-01

    Full Text Available We present a custom acoustic emission (AE monitoring system designed to perform long-term measurements on high-alpine rock walls. AE monitoring is a common technique for characterizing damage evolution in solid materials. The system is based on a two-channel AE sensor node (AE-node integrated into a wireless sensor network (WSN customized for operation in harsh environments. This wireless architecture offers flexibility in the deployment of AE-nodes at any position of the rock wall that needs to be monitored, within a range of a few hundred meters from a core station connected to the internet. The system achieves near real-time data delivery and allows the user to remotely control the AE detection threshold. In order to protect AE sensors and capture acoustic signals from specific depths of the rock wall, a special casing was developed. The monitoring system is completed by two probes that measure rock temperature and liquid water content, both probes being also integrated into the WSN. We report a first deployment of the monitoring system on a rock wall at Jungfraujoch, 3500 m a.s.l., Switzerland. While this first deployment of the monitoring system aims to support fundamental research on processes that damage rock under cold climate, the system could serve a number of other applications, including rock fall hazard surveillance or structural monitoring of concrete structures.

  7. Medical complications associated with earthquakes.

    Science.gov (United States)

    Bartels, Susan A; VanRooyen, Michael J

    2012-02-25

    Major earthquakes are some of the most devastating natural disasters. The epidemiology of earthquake-related injuries and mortality is unique for these disasters. Because earthquakes frequently affect populous urban areas with poor structural standards, they often result in high death rates and mass casualties with many traumatic injuries. These injuries are highly mechanical and often multisystem, requiring intensive curative medical and surgical care at a time when the local and regional medical response capacities have been at least partly disrupted. Many patients surviving blunt and penetrating trauma and crush injuries have subsequent complications that lead to additional morbidity and mortality. Here, we review and summarise earthquake-induced injuries and medical complications affecting major organ systems.

  8. ROCK2 mediates the proliferation of pulmonary arterial endothelial cells induced by hypoxia in the development of pulmonary arterial hypertension

    OpenAIRE

    Qiao, Feng; ZOU, ZHITIAN; Liu, Chunhui; Zhu, Xiaofeng; Wang, Xiaoqiang; YANG, CHENGPENG; JIANG, TENGJIAO; Chen, Ying

    2016-01-01

    It has been reported that RhoA activation and Rho-kinase (ROCK) expression are increased in chronic hypoxic lungs, and the long-term inhibition of ROCK markedly improves the survival of patients with pulmonary arterial hypertension (PAH). However, whether Rho-kinase α (ROCK2) participates in regulation of the growth of pulmonary arterial endothelial cells (PAECs) remains unknown. The aim of the present study was to investigate the effect of hypoxia on the proliferation of PAECs and the role o...

  9. ROCK2 mediates the proliferation of pulmonary arterial endothelial cells induced by hypoxia in the development of pulmonary arterial hypertension

    OpenAIRE

    Qiao, Feng; ZOU, ZHITIAN; Liu, Chunhui; Zhu, Xiaofeng; Wang, Xiaoqiang; YANG, CHENGPENG; JIANG, TENGJIAO; Chen, Ying

    2016-01-01

    It has been reported that RhoA activation and Rho-kinase (ROCK) expression are increased in chronic hypoxic lungs, and the long-term inhibition of ROCK markedly improves the survival of patients with pulmonary arterial hypertension (PAH). However, whether Rho-kinase α (ROCK2) participates in regulation of the growth of pulmonary arterial endothelial cells (PAECs) remains unknown. The aim of the present study was to investigate the effect of hypoxia on the proliferation of PAECs and the role o...

  10. Application of a characteristic periods-based (CPB) approach to estimate earthquake-induced displacements of landslides through dynamic numerical modelling

    Science.gov (United States)

    Martino, S.; Lenti, L.; Delgado, J.; Garrido, J.; Lopez-Casado, C.

    2016-07-01

    The interaction between seismic waves and slopes is an important topic to provide reliable scenarios for earthquake-(re)triggered landslides. The physical properties of seismic waves as well as slope topography and geology can significantly modify the local seismic response, influencing landslide triggering. A novel approach is here applied to two case studies in Andalusia (southern Spain) for computing the expected earthquake-induced displacements of existing landslide masses. Towards this aim, dynamic stress-strain numerical modelling was carried out using a selection of seismic signals characterized by different spectral content and energy. In situ geophysical measurements, consisting of noise records and temporary seismometric arrays, were carried out to control the numerical outputs in terms of local seismic response. The results consist of relationships between the characteristic period, Tm, of the seismic signals and the characteristic periods of the landslide masses, related to the thickness (Ts) and length (Tl), respectively. These relationships show that the larger the horizontal dimension (i.e. length of landslide) of a landslide is, the more effective the contribution (to the resulting coseismic displacement) of the long-period seismic waves is, as the maximum displacements are expected for a low Tm at each energy level of the input. On the other hand, when the local seismic response mainly depends on stratigraphy (i.e. landslide thickness), the maximum expected displacements occur close to the resonance period of the landslide, except for high-energy seismic inputs.

  11. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  12. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  13. ROCK2 signaling is required to induce a subset of T follicular helper cells through opposing effects on STATs in autoimmune settings

    Science.gov (United States)

    Weiss, Jonathan M.; Chen, Wei; Nyuydzefe, Melanie S.; Trzeciak, Alissa; Flynn, Ryan; Tonra, James R.; Marusic, Suzana; Blazar, Bruce R.; Waksal, Samuel D.;