Preprints
Search for earthquake (514 results)
Bayesian Dynamic Finite-Fault Inversion: 1. Method and Synthetic Test
Published: 2019-02-13
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Dynamic earthquake source inversions aim to determine the spatial distribution of initial stress and friction parameters leading to dynamic rupture models that reproduce observed ground motion data. Such inversions are challenging, particularly due to their high computational burden, thus so far only few attempts have been made. Using a highly efficient rupture simulation code, we introduce a [...]
An investigation into the role of time-dependent cohesion in interseismic fault restrengthening
Published: 2019-02-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Earthquakes typically exhibit recurrence times that far exceed time-scales attainable in a laboratory setting. To traverse the temporal gap between the laboratory and nature, the slide-hold-slide test is commonly employed as a laboratory analogue for the seismic cycle, from which the time-dependence of fault strength may be assessed. In many studies it is implicitly assumed that all fault [...]
Dynamic Rupture Propagation on Fault Planes with Explicit Representation of Short Branches
Published: 2019-02-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Active fault zones are homes for a plethora of complex structural and geometric features that are expected to affect earthquake rupture nucleation, propagation, and arrest, as well as interseismic deformation. Simulation of these complexities have been largely done using continuum plasticity or scalar damage theories. In this paper, we use a highly efficient novel hybrid finite element-spectral [...]
Effect of fault roughness on aftershock distribution: Plastic off-fault material properties
Published: 2019-02-04
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We perform spontaneous earthquake rupture simulations on rough strike- slip faults with off-fault plastic material properties. We examine the off-fault stress change and damage pattern resulting from dynamic fault slip in the near-fault region. We use the stress output from each simulation to calculate the Coulomb failure function (CFF). We calculate the CFF values at the extensional side of the [...]
Are U-Th dates correlated with historical records of earthquakes? Constraints from co-seismic carbonate veins within the North Anatolian Fault Zone
Published: 2019-01-22
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
U-Th dating of carbonate veins in connection with active tectonics has recently been used as an attractive tool for constraining the absolute timing of late Quaternary crustal deformations. In this study, for the first time we correlate U-Th ages of travertine deposits in co-seismic fissures along the North Anatolian Fault Zone (NAFZ) with records of Paleoseismological studies supported by [...]
Earthquakes within Earthquakes: Patterns in Rupture Complexity
Published: 2019-01-17
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquake source time functions carry information about the complexity of seismic rupture. We explore databases of source time functions of earthquakes and find that source time functions are composed of distinct peaks that we call subevents. We observe that earthquake complexity, as represented by the number of subevents, grows with earthquake magnitude. We find that subevent magnitudes are [...]
Seismic and aseismic fault growth lead to different fault orientations
Published: 2019-01-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Orientations of natural fault systems are subject to large variations. They often contradict classical Andersonian faulting theory as they are misoriented relative to the prevailing regional stress field. This is ascribed to local effects of structural or stress heterogeneities and reorientations of structures or stresses on the long-term. To better understand the relation between fault [...]
Development of an inversion method to extract information on fault geometry from teleseismic data
Published: 2019-01-04
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Teleseismic waveforms contain information on fault slip evolution during an earthquake, as well as on the fault geometry. A linear finite-fault inversion method is a tool for solving the slip-rate function distribution under an assumption of fault geometry as a single or multiple-fault-plane model. An inappropriate assumption of fault geometry would tend to distort the solution due to Greens [...]
Impulsive source of the 2017, Mw =7.3, Ezgeleh, Iran, earthquake
Published: 2019-01-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
On November 12th 2017, a MW =7.3 earthquake struck near the Iranian town of Ezgeleh, close to the Iran-Iraq border. This event was located within the Zagros fold and thrust belt which delimits the continental collision between the Arabian and Eurasian Plates. Despite a high seismic risk, the seismogenic behaviour of the complex network of active faults is not well documented in this area due to [...]
Wet rice cultivation was the primary cause of the earthquake-triggered Palu landslides
Published: 2019-01-03
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
The death toll and economic impact of an earthquake are greatly exacerbated when landslides are triggered by strong ground motion. These slides typically occur in two different contexts: localized failure of steep slopes that pose a major threat to life in areas below; and lateral spreading of nearly flat sediment plains due to shaking-induced liquefaction, which can damage large areas of [...]
Seismicity induced by hydraulic fracturing and wastewater disposal in the Appalachian Basin, USA - a review
Published: 2019-01-01
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Eastern Ohio is an area of North America where a significant increase in seismicity rate was noted in the early 2010s. This increase has been associated with intensification of unconventional gas extraction performed in the Appalachian Basin and has been directly linked to two processes: hydraulic fracturing and disposal of the associated wastewater. In this paper we review the recent seismicity [...]
Episodic fluid flow in an active fault
Published: 2018-12-01
Subjects: Earth Sciences, Geology, Hydrology, Physical Sciences and Mathematics, Tectonics and Structure
We present a 250 ka record of episodic fluid flow along the Malpais fault which hosts the Beowawe hydrothermal system, Nevada, USA. The history of fluid flow was quantified using a novel combination of the apatite (U-Th)/He (AHe) thermochronometer and a model of the thermal effects of fluid flow. Samples show partial resetting of the AHe thermochronometer in a 40 m wide zone around the normal [...]
Joint inversion of co-seismic and early post-seismic slip: Application to the 2009 Mw6.3 LAquila earthquake, Central Italy
Published: 2018-11-20
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Geodetic data provide static information on the displacement of the surface of the Earth, and allow for a detailed analysis of earthquake characteristics. Yet, geodetic data are generally characterized by either a good temporal or a good spatial resolution, but rarely both. This lack of resolution affects our understanding of the evolution of seismic and aseismic processes. Here, we propose a [...]
Early and persistent supershear rupture of the 2018 Mw 7.5 Palu earthquake
Published: 2018-11-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Supershear earthquakes with rupture velocity exceeding shear-wave speeds, previously observed in laboratory experiments and large strike-slip events, often have an initial sub-shear stage before they transition to supershear. In this study, integrated geophysical observations of the 2018 Mw 7.5 Palu, Indonesia earthquake, provide robust evidence of an early and persistent supershear rupture [...]
Co-location of the downdip end of seismic coupling and the continental shelf break
Published: 2018-11-08
Subjects: Earth Sciences, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics
Along subduction margins, the morphology of the near shore domain records the combined action of erosion from ocean waves and permanent tectonic deformation from the convergence of plates. We observe that at subduction margins around the globe, the edge of continental shelves tends to be located above the downdip end of seismic coupling on the megathrust (locking depth). Coastlines lie farther [...]