Journal articles: 'Seismic and aseismic slip behaviour'

1

Liu, Yajing, Jeffrey J. McGuire, and Mark D. Behn. "Aseismic transient slip on the Gofar transform fault, East Pacific Rise." Proceedings of the National Academy of Sciences 117, no. 19 (April 28, 2020): 10188–94. http://dx.doi.org/10.1073/pnas.1913625117.

Full text

Abstract:

Oceanic transform faults display a unique combination of seismic and aseismic slip behavior, including a large globally averaged seismic deficit, and the local occurrence of repeating magnitude (M) ∼6 earthquakes with abundant foreshocks and seismic swarms, as on the Gofar transform of the East Pacific Rise and the Blanco Ridge in the northeast Pacific Ocean. However, the underlying mechanisms that govern the partitioning between seismic and aseismic slip and their interaction remain unclear. Here we present a numerical modeling study of earthquake sequences and aseismic transient slip on oceanic transform faults. In the model, strong dilatancy strengthening, supported by seismic imaging that indicates enhanced fluid-filled porosity and possible hydrothermal circulation down to the brittle–ductile transition, effectively stabilizes along-strike seismic rupture propagation and results in rupture barriers where aseismic transients arise episodically. The modeled slow slip migrates along the barrier zones at speeds ∼10 to 600 m/h, spatiotemporally correlated with the observed migration of seismic swarms on the Gofar transform. Our model thus suggests the possible prevalence of episodic aseismic transients in M ∼6 rupture barrier zones that host active swarms on oceanic transform faults and provides candidates for future seafloor geodesy experiments to verify the relation between aseismic fault slip, earthquake swarms, and fault zone hydromechanical properties.

APA, Harvard, Vancouver, ISO, and other styles

2

Twardzik, Cedric, Mathilde Vergnolle, Anthony Sladen, and Louisa L. H. Tsang. "Very early identification of a bimodal frictional behavior during the post-seismic phase of the 2015 Mw 8.3 Illapel, Chile, earthquake." Solid Earth 12, no. 11 (November 9, 2021): 2523–37. http://dx.doi.org/10.5194/se-12-2523-2021.

Full text

Abstract:

Abstract. It is well-established that the post-seismic slip results from the combined contribution of seismic and aseismic processes. However, the partitioning between these two modes of deformation remains unclear due to the difficulty of inferring detailed and robust descriptions of how both evolve in space and time. This is particularly true just after a mainshock when both processes are expected to be the strongest. Using state-of-the-art sub-daily processing of GNSS data, along with dense catalogs of aftershocks obtained from template-matching techniques, we unravel the spatiotemporal evolution of post-seismic slip and aftershocks over the first 12 h following the 2015 Mw 8.3 Illapel, Chile, earthquake. We show that the very early post-seismic activity occurs over two regions with distinct behaviors. To the north, post-seismic slip appears to be purely aseismic and precedes the occurrence of late aftershocks. To the south, aftershocks are the primary cause of the post-seismic slip. We suggest that this difference in behavior could be inferred only a few hours after the mainshock. We finish by showing that this information can potentially be obtained very rapidly after a large earthquake, which could prove to be useful in forecasting the long-term spatial pattern of aftershocks.

APA, Harvard, Vancouver, ISO, and other styles

3

Alparone, Salvatore, Alessandro Bonforte, Salvatore Gambino, Sabrina Grassi, Francesco Guglielmino, Federico Latino, Gabriele Morreale, et al. "Characterization of an Active Fault through a Multiparametric Investigation: The Trecastagni Fault and Its Relationship with the Dynamics of Mt. Etna Volcano (Sicily, Italy)." Remote Sensing 14, no. 19 (September 23, 2022): 4760. http://dx.doi.org/10.3390/rs14194760.

Full text

Abstract:

The Trecastagni Fault (TF) is an important tectonic structure in the middle-lower southern flank of Mt. Etna volcano. It is characterised by evident morphological slopes with normal dip-slip ruptures that directly affect roads and buildings. The TF plays a key role in the complex framework of the volcano dynamics since it represents part of the southern boundary of the unstable sector. Seismic surveys have been performed on three different areas of the fault to gain insights into the seismic stratigraphic structure of the subsoil. We considered the seismic activity of a sector of the territory affecting the surface evidence of the Trecastagni Fault in the period between 1980 and 2021 in order to highlight the main seismic release and define the space–time distribution of seismicity. Most of the seismicity is located in the north-western portion, while the central and southern sectors are characterised by low seismic activity. The strongest earthquakes occur mainly within the first 5 km of depth in the form of swarms and/or isolated shocks. Ground deformation techniques (levelling, In-SAR and two continuous extensometers) evidence a continuous aseismic slip of the TF that is interrupted by short accelerations accompanied by shallow seismicity. The Trecastagni Fault dynamics are strictly linked to magma pressurisation and intrusive episodes of Mt. Etna that induce additional stress and promote its slip along the fault plane. Multidisciplinary data analysed in this work, evidenced the dual behaviour of the fault, from aseismic creep to stick-slip, and the relation with magmatic activity, also suggesting the time delay in the response of the fault after the intense stress induced by dyke intrusion.

APA, Harvard, Vancouver, ISO, and other styles

4

Zielke, Olaf, Danijel Schorlemmer, Sigurjon Jónsson, and Paul Martin Mai. "Magnitude-Dependent Transient Increase of Seismogenic Depth." Seismological Research Letters 91, no. 4 (June 10, 2020): 2182–91. http://dx.doi.org/10.1785/0220190392.

Full text

Abstract:

Abstract The thickness of the seismogenic zone in the Earth’s crust plays an important role in seismotectonics, affecting fault-system architecture and relative fault activity, earthquake size and distribution within a fault system, as well as long-term accumulation of tectonic deformation. Within the last two decades, several studies have revealed that aftershocks of large continental earthquakes may occur below the background depth of the seismogenic zone, that is, below the seismic–aseismic transition zone. This observation may be explained with a strain- and strain-rate-induced shift in rheological behavior that follows large mainshocks, transiently changing the deformation style below the seismogenic zone from incipient ductile to seismically brittle failure. As large earthquakes transiently deepen the seismic–aseismic transition zone, it is plausible to assume that larger mainshocks may cause stronger deepening than smaller mainshocks. Corresponding observations, however, have not yet been reported. Here, we use well-located seismic catalogs from Alaska, California, Japan, and Turkey to analyze if mainshock size positively correlates with the amount of transient deepening of the seismic–aseismic transition zone. We compare the depths of background seismicity with aftershock depths of 16 continental strike-slip earthquakes (6≤M≤7.8) and find that large mainshocks do cause stronger transient deepening than moderate-size mainshocks. We further suggest that this deepening effect also applies to the mainshocks themselves, with larger mainshock coseismic ruptures being capable of extending deeper into the normally aseismic zone. This understanding may help address fundamental questions of earthquake-source physics such as the assumed scale invariance of earthquake stress drop and whether fault-slip scales with rupture length or rupture width.

APA, Harvard, Vancouver, ISO, and other styles

5

Plattner, Christina, Alessandro Parizzi, Sara Carena, Stefanie M. Rieger, Anke M. Friedrich, Amir M. Abolghasem, and Francesco DeZan. "Long-lived afterslip of the 2013 Mw 6.1 Minab earthquake detected by Persistent Scatterer Interferometry along the Irer fault (western Makran-Zagros transition zone, Iran)." Geophysical Journal International 229, no. 1 (November 16, 2021): 171–85. http://dx.doi.org/10.1093/gji/ggab456.

Full text

Abstract:

SUMMARY The ratio of seismogenic to aseismic deformation along active faults is needed to estimate their seismogenic potential and hazards. Seismologic and geodetic methods routinely capture coseismic displacements, but data acquisition requirements to fully document post-seismic deformation are not well known. Our study documents afterslip between about 18 months and 4 years after a mid-size earthquake and, based on remote structural mapping, we document fault rupture segments not previously associated with that earthquake. Persistent scatterer interferometric analysis of Sentinel-1A aperture radar data acquired between October 2014 and December 2018 reveals prolonged post-seismic deformation following the 11 May 2013 Mw 6.1 Minab earthquake and its aftershocks. The surface deformation data yield a sharp contrast across both the main seismogenic fault (here named the Irer fault) and its northeastern splay, and it is compatible with left-lateral motion along both faults. The PSI data helped us to identify and map the splay fault in the satellite imagery. We could then measure the geological offset along both faults, finding maximum displacements of about 1 km (main fault) and 350 m (splay). Our modelling of the observed post-seismic surface deformation pattern shows that post-seismic deformation was accommodated by left-lateral afterslip, not viscoelastic relaxation. This result is consistent with previous propositions that Mw 6 earthquakes do not measurably excite deeply seated viscoelastic relaxation mechanisms. Our afterslip modelling yields a slip pattern from the surface to a depth of 6 km to maximum 16 km, in agreement with the depth of the coseismic slip-distribution, and a maximum displacement of ∼7 cm along the fault, but located ∼8 km to the east of the coseismic slip maximum. Moment release during the observed afterslip in our study is Mw 5.7, or 12% of the coseismic moment released by main shock and aftershocks together. Combined with previously published results for the early post-seismic period (first 2 months), we estimate the aseismic moment to be at least ∼37% of the total, implying a high ratio of aseismic to seismic moment release for the Irer fault. Our results show that observation time windows well beyond 5 years are needed to record afterslip following mid-sized earthquakes. Thus, progress in understanding the transition from post-seismic to interseismic fault behaviour critically depends on the availability of data provided by satellite missions such as Copernicus Sentinel-1A. Similarly, robust comparison of the post-seismic rates with long-term geological rates requires palaeoseismic study and dating of related morphotectonic features.

APA, Harvard, Vancouver, ISO, and other styles

6

Chaves, E. J., S. Y. Schwartz, and R. E. Abercrombie. "Repeating earthquakes record fault weakening and healing in areas of megathrust postseismic slip." Science Advances 6, no. 32 (August 2020): eaaz9317. http://dx.doi.org/10.1126/sciadv.aaz9317.

Full text

Abstract:

Repeating earthquakes (REs) rupture the same fault patches at different times allowing temporal variations in the mechanical behavior of specific areas of the fault to be interrogated over the earthquake cycle. We study REs that reveal fault weakening after a large megathrust earthquake in Costa Rica, followed by fault recovery. We find shorter RE recurrence intervals and larger slip areas immediately following the mainshock that both gradually return to pre-earthquake values. RE seismic moments remain nearly constant throughout the earthquake cycle. This implies a balance between fault weakening (reducing slip) and transient embrittlement (increasing rupture area by converting regions from aseismic to seismic slip), induced by the increased loading rate following the mainshock. This interpretation is consistent with positive, negative, and constant moment versus RE recurrence interval trends reported in other studies following large earthquakes and with experimental work showing slip amplitudes and stress drop decrease with loading rate.

APA, Harvard, Vancouver, ISO, and other styles

7

Leng, Ling Ye, and Peng Fei Zhang. "Research on CFRP Strengthening Corroded Reinforced Concrete Columns in Seismic Performance." Applied Mechanics and Materials 477-478 (December 2013): 681–85. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.681.

Full text

Abstract:

In recent years, CFRP is widely used both at home and abroad. The numbers of tests about the research on CFRP reinforcing corrosion concrete are more than numerical simulation. In this paper, OpenSees has been used to do the numerical simulation on nonlinear analysis of the CFRP reinforcement corrosion concrete column aseismic behavior. And the results were compared with the tests. The results show that it can well predict seismic performance of CFRP strengthening corrosion concrete by choosing reasonable material bond-slip constitutive.

APA, Harvard, Vancouver, ISO, and other styles

8

Durand, Virginie, Stephan Bentz, Grzegorz Kwiatek, Georg Dresen, Christopher Wollin, Oliver Heidbach, Patricia Martínez-Garzòn, Fabrice Cotton, Murat Nurlu, and Marco Bohnhoff. "A Two-Scale Preparation Phase Preceded an Mw 5.8 Earthquake in the Sea of Marmara Offshore Istanbul, Turkey." Seismological Research Letters 91, no. 6 (September 23, 2020): 3139–47. http://dx.doi.org/10.1785/0220200110.

Full text

Abstract:

Abstract We analyze the spatiotemporal evolution of seismicity during a sequence of moderate (an Mw 4.7 foreshock and Mw 5.8 mainshock) earthquakes occurring in September 2019 at the transition between a creeping and a locked segment of the North Anatolian fault in the central Sea of Marmara, northwest Turkey. To investigate in detail the seismicity evolution, we apply a matched-filter technique to continuous waveforms, thus reducing the magnitude threshold for detection. Sequences of foreshocks preceding the two largest events are clearly seen, exhibiting two different behaviors: a long-term activation of the seismicity along the entire fault segment and a short-term concentration around the epicenters of the large events. We suggest a two-scale preparation phase, with aseismic slip preparing the mainshock final rupture a few days before, and a cascade mechanism leading to the nucleation of the mainshock. Thus, our study shows a combination of seismic and aseismic slip during the foreshock sequence changing the strength of the fault, bringing it closer to failure.

APA, Harvard, Vancouver, ISO, and other styles

9

Erickson, Brittany A., Junle Jiang, Michael Barall, Nadia Lapusta, Eric M. Dunham, Ruth Harris, Lauren S. Abrahams, et al. "The Community Code Verification Exercise for Simulating Sequences of Earthquakes and Aseismic Slip (SEAS)." Seismological Research Letters 91, no. 2A (January 29, 2020): 874–90. http://dx.doi.org/10.1785/0220190248.

Full text

Abstract:

Abstract Numerical simulations of sequences of earthquakes and aseismic slip (SEAS) have made great progress over past decades to address important questions in earthquake physics. However, significant challenges in SEAS modeling remain in resolving multiscale interactions between earthquake nucleation, dynamic rupture, and aseismic slip, and understanding physical factors controlling observables such as seismicity and ground deformation. The increasing complexity of SEAS modeling calls for extensive efforts to verify codes and advance these simulations with rigor, reproducibility, and broadened impact. In 2018, we initiated a community code-verification exercise for SEAS simulations, supported by the Southern California Earthquake Center. Here, we report the findings from our first two benchmark problems (BP1 and BP2), designed to verify different computational methods in solving a mathematically well-defined, basic faulting problem. We consider a 2D antiplane problem, with a 1D planar vertical strike-slip fault obeying rate-and-state friction, embedded in a 2D homogeneous, linear elastic half-space. Sequences of quasi-dynamic earthquakes with periodic occurrences (BP1) or bimodal sizes (BP2) and their interactions with aseismic slip are simulated. The comparison of results from 11 groups using different numerical methods show excellent agreements in long-term and coseismic fault behavior. In BP1, we found that truncated domain boundaries influence interseismic stressing, earthquake recurrence, and coseismic rupture, and that model agreement is only achieved with sufficiently large domain sizes. In BP2, we found that complexity of fault behavior depends on how well physical length scales related to spontaneous nucleation and rupture propagation are resolved. Poor numerical resolution can result in artificial complexity, impacting simulation results that are of potential interest for characterizing seismic hazard such as earthquake size distributions, moment release, and recurrence times. These results inform the development of more advanced SEAS models, contributing to our further understanding of earthquake system dynamics.

APA, Harvard, Vancouver, ISO, and other styles

10

Menegon, Luca, and Iain Stewart. "A safer future with clues from earthquakes past." Impact 2019, no. 9 (December 20, 2019): 6–8. http://dx.doi.org/10.21820/23987073.2019.9.6.

Full text

Abstract:

Understanding the short- and long-term mechanical behaviour of the lower crust is of fundamental importance when trying to understand the earthquake cycle and related hazard along active fault zones. In some regions some 20% of intracontinental earthquakes of magnitude > 5 nucleates in the lower crust at depth of 30-40 km. For example, a significant proportion of seismicity in the Himalaya, as well as aftershocks associated with the destructive 2001 Bhuj earthquake in India, nucleated in the granulitic lower crust of the Indian shield. Earthquakes in the continental interiors are often devastating and, over the past century, have killed significantly more people than earthquakes that occurred at plate boundaries. Thus, a thorough understanding of the earthquake cycle in intracontinental settings is essential. This requires knowledge of the mechanical behaviour and of the strength (by which Earth scientists commonly mean the maximum stress that rocks can sustain before deforming) of the lower crust. The most common conceptual model of the strength of the continental crust predicts a strong, seismogenic brittle upper crust (where the base of the seismogenic layer is typically considered to be at depth of 10-15 km), and a weak, viscous, aseismic lower crust. This model has been recently questioned by the finding that the lower crust can be seismic and, therefore, mechanically strong. The question arises, how thick is the seismogenic layer in the crust? Answering this question is crucial to determine the potential hazard caused by large earthquakes, which are also generally the deepest. Our limited knowledge of the mechanical behaviour of the lower crust is largely due to the lower crust itself being poorly accessible for direct geological observations, so that most of our knowledge derives from indirect geophysical measurements (like the distribution of earthquakes). There are only a few well-exposed large sections of exhumed continental lower crust in the world. One of these is located in the Lofoten islands (northern Norway), which were exhumed from their original deep crustal position during the opening of the North Atlantic Ocean. We propose an integrated, multi-disciplinary study of a network of brittle-viscous shear zones (i.e. zones of localized intense deformation of geological materials) from Lofoten, which records episodic rapid slip events (earthquakes) alternating with long-lasting aseismic creep. The study will link structural geology (analysis of geological faults and shear zones), petrology (analysis of the composition and textures of rocks), geochemistry (detailed chemical characterization of rocks and minerals) and experimental rock deformation (to reproduce in the lab under controlled conditions the deformation processes operative in the deep Earth's crust). This integrated dataset will provide a novel, clear picture of the mechanical behaviour of the continental lower crust during the earthquake cycle. Our direct geological and experimental observations will be tested against geophysical observations of currently active seismic deformation. The cumulative results of the projects will shed light on the currently poorly constrained mechanical behaviour of the lower crust during the earthquake cycle, and therefore on the sequence of inter-seismic slip (the period of slow accumulation of elastic deformation along a fault), co-seismic slip (the sudden rupture along a fault that is the earthquake) and post-seismic slip (the immediate period after an earthquake when the crust and the fault adjust to the modified state of crustal stress caused by an earthquake). This will greatly extend and complement existing efforts by the scientific community to understand and interpret the mechanical behaviour of rocks during the earthquake cycle recorded in the lower crust and the related hazard, and will provide key input for numerical models of continental dynamics.

APA, Harvard, Vancouver, ISO, and other styles

11

Luo, Bin, Benchun Duan, and Dunyu Liu. "3D Finite-Element Modeling of Dynamic Rupture and Aseismic Slip over Earthquake Cycles on Geometrically Complex Faults." Bulletin of the Seismological Society of America 110, no. 6 (September 1, 2020): 2619–37. http://dx.doi.org/10.1785/0120200047.

Full text

Abstract:

ABSTRACT We develop a new dynamic earthquake simulator to numerically simulate both spontaneous rupture and aseismic slip over earthquake cycles on geometrically complex fault systems governed by rate- and state-dependent friction. The method is based on the dynamic finite-element method (FEM) EQdyna, which is directly used in the simulator for modeling 3D spontaneous rupture. We apply an adaptive dynamic relaxation technique and a variable time stepping scheme to EQdyna to model the quasi-static processes of an earthquake cycle, including the postseismic, interseismic, and nucleation processes. Therefore, the dynamic and quasi-static processes of an earthquake cycle are modeled in one FEM framework. Tests on a vertical strike-slip fault verify the correctness of the dynamic simulator. We apply the simulator to thrust faults with various dipping angles, which can be considered as the simplest case of geometrically complex faults by breaking symmetry, compared with vertical faults, to examine effects of dipping fault geometry on earthquake cycle behaviors. We find that shallower dipping thrust faults produce larger seismic slip and longer recurrence time over earthquake cycles with the same rupture area. In addition, we find an empirically linear scaling relation between the recurrence interval (and the seismic moment) and the sinusoidal function of the dip angle. The dip-angle dependence is likely due to the free-surface effect, because of broken symmetry. These results suggest dynamic earthquake simulators that can handle nonvertical dipping fault geometry are needed for subduction-zone earthquake studies.

APA, Harvard, Vancouver, ISO, and other styles

12

Kinscher, J. L., F. De Santis, N. Poiata, P. Bernard, K. H. Palgunadi, and I. Contrucci. "Seismic repeaters linked to weak rock-mass creep in deep excavation mining." Geophysical Journal International 222, no. 1 (April 2, 2020): 110–31. http://dx.doi.org/10.1093/gji/ggaa150.

Full text

Abstract:

SUMMARY Seismic repeaters are a phenomenon rarely observed in mining environments. In this study, we show that repeaters and associated aseismic slip can be the governing mechanism behind seismic triggering in response to excavation mining, providing new perspectives for rethinking and improving standard procedures for seismic rock burst hazard assessment and mining monitoring. Evidence comes from an extensive multiplet analysis on dense spatiotemporal microseismic event clusters (−2.5 < Mw < 1) that was recorded by a local microseismic network at the Lappberget orebody in the Garpenberg mine in Sweden at around 1 km depth. Analysis involved template matching, clustering, double-difference relocation, source parameter and mechanism estimation, as well as interevent time analysis. The results show that almost 80 per cent of the analysed events can be interpreted as seismic repeaters. Source mechanisms demonstrate systematic strike-slip faulting with a significant reverse faulting component, indicating that triggering of the repeaters is sensitive to increases in the horizontal compressive stresses. We suggest that seismic repeaters represent brittle frictional parts (asperity) of creeping, planar shaped, pre-exiting structures of several metres composed of weak rock-mass materials (e.g. talc) associated with strengthening friction behaviours. This repeater model and the here used definition of asperity thus slightly differs from its meaning in classical seismological models where repeating events are related to the locked fault patches along a creeping fault. In addition, we identified different asperity types for the different repeater families that we interpret as different friction properties. Some multiplet families represent rather a transitional case between multiplet and repeater occurrences that might imply a mixture of weakening and strengthening friction processes, that is, creep and brittle rupture along neighboured plane shaped anisotropies in a heterogeneous rock mass. The exact nature of asperities and seismic and aseismic coupling of the rock mass as well as the propagation mechanism of strain and stress associated with short-term (days to weeks) and long-term (months to years) post-blast creep remains uncertain and needs to be addressed by future investigations. The understanding of these processes is particularly important for assessing hazard of larger dynamic ruptures.

APA, Harvard, Vancouver, ISO, and other styles

13

Jiang, Junle, Yehuda Bock, and Emilie Klein. "Coevolving early afterslip and aftershock signatures of a San Andreas fault rupture." Science Advances 7, no. 15 (April 2021): eabc1606. http://dx.doi.org/10.1126/sciadv.abc1606.

Full text

Abstract:

Large earthquakes often lead to transient deformation and enhanced seismic activity, with their fastest evolution occurring at the early, ephemeral post-rupture period. Here, we investigate this elusive phase using geophysical observations from the 2004 moment magnitude 6.0 Parkfield, California, earthquake. We image continuously evolving afterslip, along with aftershocks, on the San Andreas fault over a minutes-to-days postseismic time span. Our results reveal a multistage scenario, including immediate onset of afterslip following tens-of-seconds-long coseismic shaking, short-lived slip reversals within minutes, expanding afterslip within hours, and slip migration between subparallel fault strands within days. The early afterslip and associated stress changes appear synchronized with local aftershock rates, with increasing afterslip often preceding larger aftershocks, suggesting the control of afterslip on fine-scale aftershock behavior. We interpret complex shallow processes as dynamic signatures of a three-dimensional fault-zone structure. These findings highlight important roles of aseismic source processes and structural factors in seismicity evolution, offering potential prospects for improving aftershock forecasts.

APA, Harvard, Vancouver, ISO, and other styles

14

Deng, Jian, Ming Xiao, Juntao Chen, Bingbing Xie, and Yang Yang. "Study on Fluid-Lining-Rock Coupling Interaction of Diversion Tunnel under Seismic Load." Shock and Vibration 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/680385.

Full text

Abstract:

Fluid-lining-rock coupling interaction of diversion tunnel under seismic load is a critical problem in seismic research which should be solved urgently. Based on the explicit finite element method for dynamic analysis of single-phase fluid and solid medium and combining with the boundary conditions of coupling interface, a dynamic explicit finite element solving format of diversion tunnel considering fluid-lining coupling interaction is established. In light of the basic theory of dynamic contact force method and applying the nonlinear hyperbolic constitutive model of contact surface, a dynamic explicit finite element time-domain integral equation of combined bearing of lining and surrounding rocks, which takes the bond-slip behavior of the contact surface into account, is put forward. Meanwhile, considering the dynamic interaction process of inner water and lining, lining and surrounding rocks, an explicit finite element numerical simulation analysis method of fluid-lining-rock coupling interaction of diversion tunnel under seismic load is presented. The calculation results of case study reasonably reflect the seismic response characteristics of diversion tunnel, and an effective analysis method is provided for the aseismic design of hydraulic tunnel.

APA, Harvard, Vancouver, ISO, and other styles

15

Vadacca, Luigi. "The Altotiberina Low-Angle Normal Fault (Italy) Can Fail in Moderate-Magnitude Earthquakes as a Result of Stress Transfer from Stable Creeping Fault Area." Geosciences 10, no. 4 (April 16, 2020): 144. http://dx.doi.org/10.3390/geosciences10040144.

Full text

Abstract:

Geological and geophysical evidence suggests that the Altotiberina low-angle (dip angle of 15–20 ° ) normal fault is active in the Umbria–Marche sector of the Northern Apennine thrust belt (Italy). The fault plane is 70 km long and 40 km wide, larger and hence potentially more destructive than the faults that generated the last major earthquakes in Italy. However, the seismic potential associated with the Altotiberina fault is strongly debated. In fact, the mechanical behavior of this fault is complex, characterized by locked fault patches with a potentially seismic behavior surrounded by aseismic creeping areas. No historical moderate (5 ≤ Mw ≤ 5.9) nor strong (6 ≤ Mw ≤ 6.9)-magnitude earthquakes are unambiguously associated with the Altotiberina fault; however, microseismicity is scattered below 5 km within the fault zone. Here we provide mechanical evidence for the potential activation of the Altotiberina fault in moderate-magnitude earthquakes due to stress transfer from creeping fault areas to locked fault patches. The tectonic extension in the Umbria–Marche crustal sector of the Northern Apennines is simulated by a geomechanical numerical model that includes slip events along the Altotiberina and its main seismic antithetic fault, the Gubbio fault. The seismic cycles on the fault planes are simulated by assuming rate-and-state friction. The spatial variation of the frictional parameters is obtained by combining the interseismic coupling degree of the Altotiberina fault with friction laboratory measurements on samples from the Zuccale low- angle normal fault located in the Elba island (Italy), considered an older exhumed analogue of Altotiberina fault. This work contributes a better estimate of the seismic potential associated with the Altotiberina fault and, more generally, to low-angle normal faults with mixed-mode slip behavior.

APA, Harvard, Vancouver, ISO, and other styles

16

Kato, Naoyuki. "Earthquake Cycles in a Model of Interacting Fault Patches: Complex Behavior at Transition from Seismic to Aseismic Slip." Bulletin of the Seismological Society of America 106, no. 4 (June 7, 2016): 1772–87. http://dx.doi.org/10.1785/0120150185.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Martínez-Garzón, Patricia, Grzegorz Kwiatek, Stephan Bentz, Marco Bohnhoff, and Georg Dresen. "Induced earthquake potential in geothermal reservoirs: Insights from The Geysers, California." Leading Edge 39, no. 12 (December 2020): 873–82. http://dx.doi.org/10.1190/tle39120873.1.

Full text

Abstract:

Geothermal reservoir production and associated induced seismicity may experience pronounced attention in the near future, given the ambitious plans for reducing greenhouse gas emissions toward a carbon-neutral economy and society. At some geothermal sites, the occurrence of hazard- and risk-prone induced earthquakes caused by or associated with reservoir stimulation has resulted in project shutdown (e.g., Pohang, South Korea, and Basel Deep Heat Mining, Switzerland). At other geothermal sites, the maximum event magnitudes were successfully maintained below a threshold defined by local authorities (e.g., Helsinki St1 Deep Heat project in Helsinki, Finland). In this study, we review some of our results from seismological and geomechanical reservoir characterization at The Geysers geothermal reservoir in California, USA, the largest producing geothermal field worldwide. We relate our findings to other geothermal sites to better understand the variability of reservoir behavior. In particular, we obtain a constant and relatively low seismic injection efficiency at The Geysers, which is interpreted to be related to the large energy dissipation through thermal processes and additional dissipation through aseismic slip, the latter now being considered to play a fundamental role in earthquake nucleation. We discuss some characteristics of the seismicity from The Geysers that suggest stable reservoir seismic injection efficiency and possibly low potential to rupture into large induced earthquakes, reducing the associated seismic hazard.

APA, Harvard, Vancouver, ISO, and other styles

18

Hatakeyama, Norishige, Naoki Uchida, Toru Matsuzawa, and Wataru Nakamura. "Emergence and disappearance of interplate repeating earthquakes following the 2011 M9.0 Tohoku-oki earthquake: Slip behavior transition between seismic and aseismic depending on the loading rate." Journal of Geophysical Research: Solid Earth 122, no. 7 (July 2017): 5160–80. http://dx.doi.org/10.1002/2016jb013914.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Goebel, Thomas H. W., and Manoochehr Shirzaei. "More Than 40 yr of Potentially Induced Seismicity Close to the San Andreas Fault in San Ardo, Central California." Seismological Research Letters 92, no. 1 (November 11, 2020): 187–98. http://dx.doi.org/10.1785/0220200276.

Full text

Abstract:

Abstract Evidence for fluid-injection-induced seismicity is rare in California hydrocarbon basins, despite widespread injection close to seismically active faults. We investigate a potential case of injection-induced earthquakes associated with San Ardo oilfield operations that began in the early 1950s. The largest potentially induced events occurred in 1955 (ML 5.2) and 1985 (Mw 4.5) within ∼6 km from the oilfield. We analyze Synthetic Aperture Radar interferometric images acquired by Sentinel-1A/B satellites between 2016 and 2020 and find surface deformation of up to 1.5 cm/yr, indicating pressure-imbalance in parts of the oilfield. Fluid injection in San Ardo is concentrated within highly permeable rocks directly above the granitic basement at a depth of ∼800 m. Seismicity predominantly occurs along basement faults at 6–13 km depths. Seismicity and wastewater disposal wells are spatially correlated to the north of the oilfield. Temporal correlations are observed over more than 40 yr with correlation coefficients of up to 0.71 for seismicity within a 24 km distance from the oilfield. Such large distances have not previously been observed in California but are similar to the large spatial footprint of injection in Oklahoma. The San Ardo seismicity shows anomalous clustering with earthquakes consistently occurring at close spatial proximity but long interevent times. Similar clustering has previously been reported in California geothermal fields and may be indicative of seismicity driven by long-term, spatially persistent external forcing. The complexity of seismic behavior at San Ardo suggests that multiple processes, such as elastic stress transfer and aseismic slip transients, contribute to the potentially induced earthquakes. The present observations show that fluid-injection operations occur close to seismically active faults in California. Yet, seismicity is predominantly observed on smaller unmapped faults with little observational evidence that large faults are sensitive to induced stress changes.

APA, Harvard, Vancouver, ISO, and other styles

20

Nagaya, Takayoshi, Atsushi Okamoto, Ryosuke Oyanagi, Yusuke Seto, Akira Miyake, Masaoki Uno, Jun Muto, and Simon R. Wallis. "Crystallographic preferred orientation of talc determined by an improved EBSD procedure for sheet silicates: Implications for anisotropy at the slab–mantle interface due to Si-metasomatism." American Mineralogist 105, no. 6 (June 1, 2020): 873–93. http://dx.doi.org/10.2138/am-2020-7006.

Full text

Abstract:

Abstract Talc is widely distributed over the Earth's surface and is predicted to be formed in various tectonic settings. Talc is a very soft and anisotropic sheet silicate showing very low friction behavior. Therefore, the formation of talc is expected to weaken the strength of talc-bearing rocks and may be associated with the initiation of subduction, and with a decrease in the coupling coefficient resulting in aseismic movements along faults and shear zones within subduction zones. For these reasons, understanding the crystallographic preferred orientation (CPO) of talc is important to quantify the anisotropy and physical properties of the host rock. However, it is difficult to measure a significant number of talc crystal orientations and to evaluate the accuracy of the measurements using electron-backscattered diffraction (EBSD). Therefore, talc CPO has not been reported, and there is uncertainty regarding the estimation of the strength of deformed talc-bearing rocks. Using methods developed for antigorite, we report the first successful EBSD measurements of talc CPO from a talc schist formed due to Simetasomatism of ultramafic rocks by subduction zone fluids. We used a combination of W-SEM and FE-SEM measurements to examine domains of various grain sizes of talc. In addition, we used TEM measurements to evaluate the accuracy of the EBSD measurements and discuss the results of talc CPO analysis. Talc CPO in the present study shows a strong concentration of the pole to the (001) plane normal to the foliation. The strongest concentration of the [100] direction is parallel to the lineation. The talc schist produces similar S-wave splitting and P- and S-wave anisotropy as antigorite schist in deeper domains, thus identifying talc-rich layers in subduction zones may require a combination of geophysical surveys, seismic observations, and anisotropy modeling. The presence of strong talc CPO in rocks comprising the slab–mantle interface boundary may promote spatial expansion of the slip area during earthquakes along the base of the mantle wedge.

APA, Harvard, Vancouver, ISO, and other styles

21

Senatorski, Piotr. "Effect of Slip-Weakening Distance on Seismic–Aseismic Slip Patterns." Pure and Applied Geophysics 176, no. 9 (January 22, 2019): 3975–92. http://dx.doi.org/10.1007/s00024-019-02094-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Dresen, Georg, Grzegorz Kwiatek, Thomas Goebel, and Yehuda Ben-Zion. "Seismic and Aseismic Preparatory Processes Before Large Stick–Slip Failure." Pure and Applied Geophysics 177, no. 12 (October 26, 2020): 5741–60. http://dx.doi.org/10.1007/s00024-020-02605-x.

Full text

Abstract:

AbstractNatural earthquakes often have very few observable foreshocks which significantly complicates tracking potential preparatory processes. To better characterize expected preparatory processes before failures, we study stick-slip events in a series of triaxial compression tests on faulted Westerly granite samples. We focus on the influence of fault roughness on the duration and magnitude of recordable precursors before large stick–slip failure. Rupture preparation in the experiments is detectable over long time scales and involves acoustic emission (AE) and aseismic deformation events. Preparatory fault slip is found to be accelerating during the entire pre-failure loading period, and is accompanied by increasing AE rates punctuated by distinct activity spikes associated with large slip events. Damage evolution across the fault zones and surrounding wall rocks is manifested by precursory decrease of seismic b-values and spatial correlation dimensions. Peaks in spatial event correlation suggest that large slip initiation occurs by failure of multiple asperities. Shear strain estimated from AE data represents only a small fraction (< 1%) of total shear strain accumulated during the preparation phase, implying that most precursory deformation is aseismic. The relative contribution of aseismic deformation is amplified by larger fault roughness. Similarly, seismic coupling is larger for smooth saw-cut faults compared to rough faults. The laboratory observations point towards a long-lasting and continuous preparation process leading to failure and large seismic events. The strain partitioning between aseismic and observable seismic signatures depends on fault structure and instrument resolution.

APA, Harvard, Vancouver, ISO, and other styles

23

Reinen, Linda A. "Seismic and aseismic slip indicators in serpentinite gouge." Geology 28, no. 2 (February 2000): 135–38. http://dx.doi.org/10.1130/0091-7613(2000)028<0135:saasii>2.3.co;2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Reinen, Linda A. "Seismic and aseismic slip indicators in serpentinite gouge." Geology 28, no. 2 (2000): 135. http://dx.doi.org/10.1130/0091-7613(2000)28<135:saasii>2.0.co;2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Passarelli, Luigi, Paul Antony Selvadurai, Eleonora Rivalta, and Sigurjón Jónsson. "The source scaling and seismic productivity of slow slip transients." Science Advances 7, no. 32 (August 2021): eabg9718. http://dx.doi.org/10.1126/sciadv.abg9718.

Full text

Abstract:

Slow slip events (SSEs) represent a slow faulting process leading to aseismic strain release often accompanied by seismic tremor or earthquake swarms. The larger SSEs last longer and are often associated with intense and energetic tremor activity, suggesting that aseismic slip controls tremor genesis. A similar pattern has been observed for SSEs that trigger earthquake swarms, although no comparative studies exist on the source parameters of SSEs and tremor or earthquake swarms. We analyze the source scaling of SSEs and associated tremor- or swarm-like seismicity through our newly compiled dataset. We find a correlation between the aseismic and seismic moment release indicating that the shallower SSEs produce larger seismic moment release than deeper SSEs. The scaling may arise from the heterogeneous frictional and rheological properties of faults prone to SSEs and is mainly controlled by temperature. Our results indicate that similar physical phenomena govern tremor and earthquake swarms during SSEs.

APA, Harvard, Vancouver, ISO, and other styles

26

Perfettini, Hugo, Jean-Philippe Avouac, Hernando Tavera, Andrew Kositsky, Jean-Mathieu Nocquet, Francis Bondoux, Mohamed Chlieh, et al. "Seismic and aseismic slip on the Central Peru megathrust." Nature 465, no. 7294 (May 2010): 78–81. http://dx.doi.org/10.1038/nature09062.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Beeler, N. M. "Constructing Constitutive Relationships for Seismic and Aseismic Fault Slip." Pure and Applied Geophysics 166, no. 10-11 (July 29, 2009): 1775–98. http://dx.doi.org/10.1007/s00024-009-0523-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Tan, Wen Di, Li Zhu, and Te Liang Yan. "Under the Action of Earthquake Ancient Timber Building Column Small Feet Slip Phenomenon Analysis." Applied Mechanics and Materials 353-356 (August 2013): 1930–33. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.1930.

Full text

Abstract:

In ancient China timber building earthquake damage records, often about "column small feet slip", scholars in ancient timber buildings for the seismic performance study, also thought that "column small feet slip" is one of the reasons for the ancient building in the earthquake Could be survived. This article through to column small feet slip phenomenon, to lead to column small feet slip condition were analyzed, and "column small feet slip" seismic effect evaluation, is to the ancient timber aseismic performance research achievements added.

APA, Harvard, Vancouver, ISO, and other styles

29

Eyre, Thomas S., Megan Zecevic, Rebecca O. Salvage, and David W. Eaton. "A Long-Lived Swarm of Hydraulic Fracturing-Induced Seismicity Provides Evidence for Aseismic Slip." Bulletin of the Seismological Society of America 110, no. 5 (July 14, 2020): 2205–15. http://dx.doi.org/10.1785/0120200107.

Full text

Abstract:

ABSTRACT Seismic swarms are defined as an increase in seismicity that does not show a clear mainshock–aftershock sequence. Typically, swarms are primarily associated with either fluid migration or slow earthquakes (aseismic slip). In this study, we analyze a swarm induced by hydraulic fracturing (HF) that persisted for an unusually long duration of more than 10 months. Swarms ascribed to fluid injection are usually characterized by an expanding seismicity front; in this case, however, characteristics such as a relatively steady seismicity rate over time and lack of hypocenter migration cannot be readily explained by a fluid-diffusion model. Here, we show that a different model for HF-induced seismicity, wherein an unstable region of a fault is loaded by proximal, pore-pressure-driven aseismic slip, better explains our observations. According to this model, the steady seismicity rate can be explained by a steady slip velocity, while the spatial stationarity of the event distribution is due to lateral confinement of the creeping region of the fault with increased pore pressure. Our results may have important implications for other induced or natural seismic swarms, which could be similarly explained by aseismic loading of asperities driven by fluid overpressure rather than the often-attributed fluid-migration model.

APA, Harvard, Vancouver, ISO, and other styles

30

Steer, Philippe, Thomas Croissant, Edwin Baynes, and Dimitri Lague. "Statistical modelling of co-seismic knickpoint formation and river response to fault slip." Earth Surface Dynamics 7, no. 3 (July 24, 2019): 681–706. http://dx.doi.org/10.5194/esurf-7-681-2019.

Full text

Abstract:

Abstract. Most landscape evolution models adopt the paradigm of constant and uniform uplift. It results that the role of fault activity and earthquakes on landscape building is understood under simplistic boundary conditions. Here, we develop a numerical model to investigate river profile development subjected to fault displacement by earthquakes and erosion. The model generates earthquakes, including mainshocks and aftershocks, that respect the classical scaling laws observed for earthquakes. The distribution of seismic and aseismic slip can be partitioned following a spatial distribution of mainshocks along the fault plane. Slope patches, such as knickpoints, induced by fault slip are then migrated at a constant rate upstream a river crossing the fault. A major result is that this new model predicts a uniform distribution of earthquake magnitude rupturing a river that crosses a fault trace and in turn a negative exponential distribution of knickpoint height for a fully coupled fault, i.e. with only co-seismic slip. Increasing aseismic slip at shallow depths, and decreasing shallow seismicity, censors the magnitude range of earthquakes cutting the river towards large magnitudes and leads to less frequent but higher-amplitude knickpoints, on average. Inter-knickpoint distance or time between successive knickpoints follows an exponential decay law. Using classical rates for fault slip (15 mm year−1) and knickpoint retreat (0.1 m year−1) leads to high spatial densities of knickpoints. We find that knickpoint detectability, relatively to the resolution of topographic data, decreases with river slope that is equal to the ratio between fault slip rate and knickpoint retreat rate. Vertical detectability is only defined by the precision of the topographic data that sets the lower magnitude leading to a discernible offset. Considering a retreat rate with a dependency on knickpoint height leads to the merging of small knickpoints into larger ones and larger than the maximum offset produced by individual earthquakes. Moreover, considering simple scenarios of fault burial by intermittent sediment cover, driven by climatic changes or linked to earthquake occurrence, leads to knickpoint distributions and river profiles markedly different from the case with no sediment cover. This highlights the potential role of sediments in modulating and potentially altering the expression of tectonic activity in river profiles and surface topography. The correlation between the topographic profiles of successive parallel rivers cutting the fault remains positive for distance along the fault of less than half the maximum earthquake rupture length. This suggests that river topography can be used for paleo-seismological analysis and to assess fault slip partitioning between aseismic and seismic slip. Lastly, the developed model can be coupled to more sophisticated landscape evolution models to investigate the role of earthquakes on landscape dynamics.

APA, Harvard, Vancouver, ISO, and other styles

31

Chen, Jiangong, Zejun Yang, Richeng Hu, and Haiquan Zhang. "Study on the Seismic Active Earth Pressure by Variational Limit Equilibrium Method." Shock and Vibration 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/4158785.

Full text

Abstract:

In the framework of limit equilibrium theory, the isoperimetric model of functional extremum regarding the seismic active earth pressure is deduced according to the variational method. On this basis, Lagrange multipliers are introduced to convert the problem of seismic active earth pressure into the problem on the functional extremum of two undetermined function arguments. Based on the necessary conditions required for the existence of functional extremum, the function of the slip surface and the normal stress distribution on the slip surface is obtained, and the functional extremum problem is further converted into a function optimization problem with two undetermined Lagrange multipliers. The calculated results show that the slip surface is a plane and the seismic active earth pressure is minimal when the action point is at the lower limit position. As the action point moves upward, the slip surface becomes a logarithmic spiral and the corresponding value of seismic active earth pressure increases in a nonlinear manner. And the seismic active earth pressure is maximal at the upper limit position. The interval estimation constructed by the minimum and maximum values of seismic active earth pressure can provide a reference for the aseismic design of gravity retaining walls.

APA, Harvard, Vancouver, ISO, and other styles

32

Garagash, D. I. "Seismic and aseismic slip pulses driven by thermal pressurization of pore fluid." Journal of Geophysical Research: Solid Earth 117, B4 (April 2012): n/a. http://dx.doi.org/10.1029/2011jb008889.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Chlieh, M., P. A. Mothes, J. M. Nocquet, P. Jarrin, P. Charvis, D. Cisneros, Y. Font, et al. "Distribution of discrete seismic asperities and aseismic slip along the Ecuadorian megathrust." Earth and Planetary Science Letters 400 (August 2014): 292–301. http://dx.doi.org/10.1016/j.epsl.2014.05.027.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Rousset, Baptiste, Roland Bürgmann, and Michel Campillo. "Slow slip events in the roots of the San Andreas fault." Science Advances 5, no. 2 (February 2019): eaav3274. http://dx.doi.org/10.1126/sciadv.aav3274.

Full text

Abstract:

Episodic tremor and accompanying slow slip are observed at the down-dip edge of subduction seismogenic zones. While tremors are the seismic signature of this phenomenon, they correspond to a small fraction of the moment released; thus, the associated fault slip can be quantified only by geodetic observations. On continental strike-slip faults, tremors have been observed in the roots of the Parkfield segment of the San Andreas fault. However, associated transient aseismic slip has never been detected. By making use of the timing of transient tremor activity and the dense Parkfield-area global positioning system network, we can detect deep slow slip events (SSEs) at 16-km depth on the Parkfield segment with an average moment equivalent toMw4.90 ± 0.08. Characterization of transient SSEs below the Parkfield locked asperity, at the transition with the creeping section of the San Andreas fault, provides new constraints on the seismic cycle in this region.

APA, Harvard, Vancouver, ISO, and other styles

35

Li, Chenglong, Guohong Zhang, Xinjian Shan, Dezheng Zhao, Yanchuan Li, Zicheng Huang, Rui Jia, Jin Li, and Jing Nie. "Surface Rupture Kinematics and Coseismic Slip Distribution during the 2019 Mw7.1 Ridgecrest, California Earthquake Sequence Revealed by SAR and Optical Images." Remote Sensing 12, no. 23 (November 27, 2020): 3883. http://dx.doi.org/10.3390/rs12233883.

Full text

Abstract:

The 2019 Ridgecrest, California earthquake sequence ruptured along a complex fault system and triggered seismic and aseismic slips on intersecting faults. To characterize the surface rupture kinematics and fault slip distribution, we used optical images and Interferometric Synthetic Aperture Radar (InSAR) observations to reconstruct the displacement caused by the earthquake sequence. We further calculated curl and divergence from the north-south and east-west components, to effectively identify the surface rupture traces. The results show that the major seismogenic fault had a length of ~55 km and strike of 320° and consisted of five secondary faults. On the basis of the determined multiple-fault geometries, we inverted the coseismic slip distributions by InSAR measurements, which indicates that the Mw7.1 mainshock was dominated by the right-lateral strike-slip (maximum strike-slip of ~5.8 m at the depth of ~7.5 km), with a small dip-slip component (peaking at ~1.8 m) on an east-dipping fault. The Mw6.4 foreshock was dominated by the left-lateral strike-slip on a north-dipping fault. These earthquakes triggered obvious aseismic creep along the Garlock fault (117.3° W–117.5° W). These results are consistent with the rupture process of the earthquake sequence, which featured a complicated cascading rupture rather than a single continuous rupture front propagating along multiple faults.

APA, Harvard, Vancouver, ISO, and other styles

36

Romano, F., I. Molinari, S. Lorito, and A. Piatanesi. "Source of the 6 February 2013 Mw = 8.0 Santa Cruz Islands Tsunami." Natural Hazards and Earth System Sciences 15, no. 6 (June 26, 2015): 1371–79. http://dx.doi.org/10.5194/nhess-15-1371-2015.

Full text

Abstract:

Abstract. On 6 February 2013 an Mw = 8.0 subduction earthquake occurred close to Santa Cruz Islands at the transition between the Solomon and the New Hebrides Trench. The ensuing tsunami caused significant inundation on the closest Nendo Island. The seismic source was studied with teleseismic broadband P-wave inversion optimized with tsunami forward modelling at DART buoys (Lay et al., 2013) and with inversion of teleseismic body and surface waves (Hayes et al., 2014a). The two studies also use different hypocentres and different planar fault models and found quite different slip models. In particular, Hayes et al. (2014a) argued for an aseismic slip patch SE from the hypocentre. We here develop a 3-D model of the fault surface from seismicity analysis and retrieve the tsunami source by inverting DART and tide-gauge data. Our tsunami source model features a main slip patch (peak value of ~ 11 m) SE of the hypocentre and reaching the trench. The rake direction is consistent with the progressively more oblique plate convergence towards the Solomon trench. The tsunami source partially overlaps the hypothesized aseismic slip area, which then might have slipped coseismically.

APA, Harvard, Vancouver, ISO, and other styles

37

Romano, F., I. Molinari, S. Lorito, and A. Piatanesi. "Source of the 6 February 2013 Mw 8.0 Santa Cruz Islands Tsunami." Natural Hazards and Earth System Sciences Discussions 3, no. 3 (March 16, 2015): 1949–70. http://dx.doi.org/10.5194/nhessd-3-1949-2015.

Full text

Abstract:

Abstract. On 6 February 2013 an Mw 8.0 subduction earthquake occurred close to Santa Cruz Islands at the transition between the Solomon and the New Hebrides Trench. The ensuing tsunami caused significant inundation on the closest Nendo Island. The seismic source was studied with teleseismic broadband P waves inversion optimized with tsunami forward modeling at DART buoys (Lay et al., 2013), and with inversion of teleseismic body and surface waves (Hayes et al., 2014). The two studies also use different hypocenters and different planar fault models, and found quite different slip models. In particular, Hayes et al. (2014) argued for an aseismic slip patch SE from the hypocenter. We here develop a 3-D model of the fault surface from seismicity analysis and retrieve the tsunami source by inverting DART and tide-gauge data. Our tsunami source model features a main slip patch (peak value of ~11 m) SE of the hypocentre, and reaching to the trench. The rake direction is consistent with the progressively more oblique plate convergence towards the Solomon trench. The tsunami source partially overlaps the hypothesized aseismic slip area, which then might have slipped coseismically.

APA, Harvard, Vancouver, ISO, and other styles

38

Dragoni, Michele, and Andrea Tallarico. "Interaction between seismic and aseismic slip along a transcurrent plate boundary: a model for seismic sequences." Physics of the Earth and Planetary Interiors 72, no. 1-2 (July 1992): 49–57. http://dx.doi.org/10.1016/0031-9201(92)90048-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Avouac, Jean-Philippe. "From Geodetic Imaging of Seismic and Aseismic Fault Slip to Dynamic Modeling of the Seismic Cycle." Annual Review of Earth and Planetary Sciences 43, no. 1 (May 30, 2015): 233–71. http://dx.doi.org/10.1146/annurev-earth-060614-105302.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Louie, John N., Clarence R. Allen, David C. Johnson, Paul C. Haase, and Stephen N. Cohn. "Fault slip in southern California." Bulletin of the Seismological Society of America 75, no. 3 (June 1, 1985): 811–33. http://dx.doi.org/10.1785/bssa0750030811.

Full text

Abstract:

Abstract Measurements of slip on major faults in southern California have been performed over the past 18 yr using principally theodolite alignment arrays and tautwire extensometers. They provide geodetic control within a few hundred meters of the fault traces, which complements measurements made by other techniques at larger distances. Approximately constant slip rates of from 0.5 to 5 mm/yr over periods of several years have been found for the southwestern portion of the Garlock fault, the Banning and San Andreas faults in the Coachella Valley, the Coyote Creek fault, the Superstition Hills fault, and an unnamed fault 20 km west of El Centro. These slip rates are typically an order of magnitude below displacement rates that have been geodetically measured between points at greater distances from the fault traces. Exponentially decaying postseismic slip in the horizontal and vertical directions due to the 1979 Imperial Valley earthquake has been measured. It is similar in magnitude to the coseismic displacements. Analysis of seismic activity adjacent to slipping faults has shown that accumulated seismic moment is insufficient to explain either the constant or the decaying postseismic slip. Thus the mechanism of motion may differ from that of slipping faults in central California, which move at rates close to the plate motion and are accompanied by sufficient seismic moment. Seismic activity removed from the slipping faults in southern California may be driving their relatively aseismic motion.

APA, Harvard, Vancouver, ISO, and other styles

41

Nedimović, Mladen R., Roy D. Hyndman, Kumar Ramachandran, and George D. Spence. "Reflection signature of seismic and aseismic slip on the northern Cascadia subduction interface." Nature 424, no. 6947 (July 2003): 416–20. http://dx.doi.org/10.1038/nature01840.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Thomas, Marion Y., Jean-Philippe Avouac, Johann Champenois, Jian-Cheng Lee, and Long-Chen Kuo. "Spatiotemporal evolution of seismic and aseismic slip on the Longitudinal Valley Fault, Taiwan." Journal of Geophysical Research: Solid Earth 119, no. 6 (June 2014): 5114–39. http://dx.doi.org/10.1002/2013jb010603.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Shirzaei, M., R. Bürgmann, N. Uchida, Y. Hu, F. Pollitz, and T. Matsuzawa. "Seismic versus aseismic slip: Probing mechanical properties of the northeast Japan subduction zone." Earth and Planetary Science Letters 406 (November 2014): 7–13. http://dx.doi.org/10.1016/j.epsl.2014.08.035.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Meng, Chunfang, Chen Gu, and Bradford Hager. "An Eshelby Solution‐Based Finite‐Element Approach to Heterogeneous Fault‐Zone Modeling." Seismological Research Letters 91, no. 1 (October 16, 2019): 465–74. http://dx.doi.org/10.1785/0220190083.

Full text

Abstract:

Abstract We present a fundamental solution‐based finite‐element (FE) method to homogenize heterogeneous elastic medium, that is, fault zone, under static, and dynamic loading. This method incorporates Eshelby’s strain perturbation into FE weak forms. The resulting numerical model implicitly considers the existence of inhomogeneity bodies within each element, without introducing additional degrees of freedom. The new method is implemented within an open‐source FE package that is applicable to alternating seismic and aseismic cycles. To demonstrate this method, we modify a dynamic fault‐slip problem, hosted at Southern California Earthquake Center (SCEC), by introducing a fault zone that contains different microstructures than the host matrix. The preliminary results suggest that the fault‐zone microstructure orientation has effects on fault slip, seismic arrivals and waveform frequency contents.

APA, Harvard, Vancouver, ISO, and other styles

45

LEKKAS, E. L. "The 1999 eartquake activity in Izmit, NW Turkey. An opportunity for the study of actualistic strike-slip related tectonic forms." Bulletin of the Geological Society of Greece 34, no. 4 (January 1, 2001): 1523. http://dx.doi.org/10.12681/bgsg.17258.

Full text

Abstract:

The 1999 earthquake activity in the area of Izmit - Bolu, Turkey, which included two major shocks, on the 17th Aug. and 12th Nov. 1999, was caused by the reactivation of fault segments that belong to NAFZ. Field research was focused on fault geometry and slip characteristics, and allowed us to distinguish seven successive right-stepping reactivated segments and the related oversteps. Investigations showed that there is good match between the observed structures and those produced by experimental modelling. Finally, an estimation is made as to the percentage of seismic and aseismic slip on the reactivated segment of the fault zone

APA, Harvard, Vancouver, ISO, and other styles

46

Araya, Maria C., and Juliet Biggs. "Deformation associated with sliver transport in Costa Rica: seismic and geodetic observations of the July 2016 Bijagua earthquake sequence." Geophysical Journal International 220, no. 1 (October 21, 2019): 585–97. http://dx.doi.org/10.1093/gji/ggz474.

Full text

Abstract:

SUMMARY Tectonic slivers form in the overriding plate in regions of oblique subduction. The inner boundaries of the sliver are often poorly defined and can consist of well-defined faults, rotating blocks or diffuse fault systems, which pass through or near the volcanic arc. The Guanacaste Volcanic Arc Sliver (GVAS) as defined by Montero et al., is a segment of the Central American Forearc Sliver, whose inner boundary is the ∼87-km-long Haciendas-Chiripa fault system (HCFS), which is located ∼10 km behind the volcanic arc and consists of strike slip faults and pull apart steps. We characterize the current ground motion on this boundary by combining earthquake locations and focal mechanisms of the 2016 Bijagua earthquake sequence, with the surface ground deformation obtained from Interferometric Synthetic Aperture Radar (InSAR) images from the ALOS-2 satellite. The coseismic stack of interferograms show ∼6 cm of displacement towards the line of sight of the satellite between the Caño Negro fault and the Upala fault, indicating uplift or SE horizontal surface displacement. The largest recorded earthquake of the sequence was Mw 5.4, and the observed deformation is one of the smallest earthquakes yet detected by InSAR in the Central American region. Forward and inverse models show the surface deformation can be partially explained by slip on a single fault, but it can be better explained by slip along two faults linked at depth. The best-fitting model consists of 0.33 m of right lateral slip on the Caño Negro fault and 0.35 m of reverse slip on the Upala fault, forming a positive flower structure. As no reverse seismicity was recorded, we infer the slip on the Upala fault occurred aseismically. Observations of the Bijagua earthquake sequence suggests the forearc sliver boundary is a complex and diffuse fault system. There are localized zones of transpression and transtension and areas where there is no surface expression suggesting the fault system is not yet mature. Although aseismic slip is common on subduction interfaces and mature strike-slip faults, this is the first study to document aseismic slip on a continental tectonic sliver boundary fault.

APA, Harvard, Vancouver, ISO, and other styles

47

Ando, Ryosuke, Naoto Takeda, and Teruo Yamashita. "Propagation dynamics of seismic and aseismic slip governed by fault heterogeneity and Newtonian rheology." Journal of Geophysical Research: Solid Earth 117, B11 (November 2012): n/a. http://dx.doi.org/10.1029/2012jb009532.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

van der Elst, Nicholas J., Andrew A. Delorey, David R. Shelly, and Paul A. Johnson. "Fortnightly modulation of San Andreas tremor and low-frequency earthquakes." Proceedings of the National Academy of Sciences 113, no. 31 (July 18, 2016): 8601–5. http://dx.doi.org/10.1073/pnas.1524316113.

Full text

Abstract:

Earth tides modulate tremor and low-frequency earthquakes (LFEs) on faults in the vicinity of the brittle−ductile (seismic−aseismic) transition. The response to the tidal stress carries otherwise inaccessible information about fault strength and rheology. Here, we analyze the LFE response to the fortnightly tide, which modulates the amplitude of the daily tidal stress over a 14-d cycle. LFE rate is highest during the waxing fortnightly tide, with LFEs most strongly promoted when the daily stress exceeds the previous peak stress by the widest margin. This pattern implies a threshold failure process, with slip initiated when stress exceeds the local fault strength. Variations in sensitivity to the fortnightly modulation may reflect the degree of stress concentration on LFE-producing brittle asperities embedded within an otherwise aseismic fault.

APA, Harvard, Vancouver, ISO, and other styles

49

McGuire, Jeffrey J., Rowena B. Lohman, Rufus D. Catchings, Michael J. Rymer, and Mark R. Goldman. "Relationships among seismic velocity, metamorphism, and seismic and aseismic fault slip in the Salton Sea Geothermal Field region." Journal of Geophysical Research: Solid Earth 120, no. 4 (April 2015): 2600–2615. http://dx.doi.org/10.1002/2014jb011579.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Lai, Jie, Yun Liu, and Wei Wang. "Shaking Table Tests on a New Antislide Pile under Earthquakes." Mathematical Problems in Engineering 2021 (January 18, 2021): 1–10. http://dx.doi.org/10.1155/2021/9304705.

Full text

Abstract:

A retaining form of a shock-absorbing antislide pile is proposed for slope engineering. A flexible material (shock-absorption layer) is filled in front of an ordinary antislide pile, which is used to absorb a large amount of seismic energy, thereby decreasing the transmission of seismic energy to the antislide pile. The flexible material thus reduces the seismic response, hence improving the aseismic capacity of the antislide pile. To verify the seismic performance of the shock-absorbing antislide pile, a shaking table contrast test was conducted and the results were compared with those from an ordinary antislide pile. The test results show that the flexible material absorbs a portion of the seismic deformation of the slip mass, decreasing the final displacement of the shock-absorbing antislide pile compared to that of the ordinary antislide pile, thereby reducing the sensitivity of the pile body to the displacement. Under the same conditions, the acceleration response of the slope body at the same height is lower for the shock-absorbing antislide pile than that for the ordinary pile, with the seismic performance of the former being superior to that of the latter. Furthermore, the shock-absorbing antislide pile is similar to the ordinary pile in terms of the dynamic earth pressure distribution form of the pile shaft; however, its value is relatively smaller, and the former exhibits better dynamic stress performance than the latter. The test results should prove useful for aseismic design of slopes.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Seismic and aseismic slip behaviour'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles