Preprints
Filtering by Subject: Geophysics and Seismology
Development of an inversion method to extract information on fault geometry from teleseismic data
Published: 2019-01-03
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 [...]
A New Method for Simultaneously Determining The Magnitude And Orientation of SHmax And Rock Strength Using Wellbore Failures in Deviated Wells
Published: 2019-01-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Forward constraining of the magnitude of SHmax on a stress polygon using wellbore failures observed from deviated wells requires the orientation of SHmax known a priori. This orientation can be separately determined from, e.g., wellbore failures in vertical/near-vertical wells. Unfortunately, in the case where image logs are available only in highly deviated wells, SHmax orientation cannot be [...]
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 [...]
Hydromechanical–Stochastic Modeling of Fluid-Induced Seismicity in Fractured Poroelastic Media
Published: 2019-01-01
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We present a new method for modeling fluid-perturbation induced seismicity in a fluid-saturated poroelastic medium embedded with a dual network of fractures. The inter-seismic triggering is deterministically modeled using a quasi-static, nonlinear and fluid-solid fully coupled fracture-poro-mechanical approach that resolves only the large-scale fractures. The co-seismic dynamic rupture is not [...]
The Warnie Volcanic Province: A Jurassic Volcanic Province in Central Australia
Published: 2018-12-12
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Stratigraphy, Volcanology
The Cooper and Eromanga Basins of South Australia and Queensland are the largest onshore hydrocarbon 9 producing region in Australia. Igneous rocks have been documented infrequently within end of well reports over 10 the past 34 years, with a late Triassic to Jurassic age determined from well data. However, the areal extent and 11 nature of these basaltic rocks were largely unclear. Here, we [...]
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: 2018-11-09
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 [...]
A Simple Model for Deglacial Meltwater Pulses
Published: 2018-11-08
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics
Evidence from radiocarbon dating and complex ice sheet modeling suggests that the fastest rate of sea level rise in Earths recent history coincided with collapse of the ice saddle between the Laurentide and Cordilleran ice sheets during the last deglaciation. In this study, we derive a simple, two-equation model of two ice sheets intersecting in an ice saddle. We show that two conditions are [...]
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 [...]
An investigation of multi-fault rupture scenarios using a variety of Coulomb stress modelling criteria: methods paper and full results
Published: 2018-11-07
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
A series of Coulomb stress models are used to simulate the independently-derived (Holden et al., 2011) rupture process of Mw 7.1 Darfield earthquake. The 7-fault source model of Beavan et al. (2012) is used for all models. Model differences include (i) differences in the static stress thresholds (0,1,5,10 MPa) that must be reached or exceeded to initiate rupture on a receiver fault, (ii) [...]
Growth folds above propagating normal faults
Published: 2018-11-07
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
Growth folds above the upper tips of normal faults are ubiquitous in extensional settings, especially during the early phases of extension and in salt-rich basins. As slip accumulates on the underlying normal fault, the geometry and size of the fold changes. These changes reflect the dip, throw, displacement and propagation rate of the underlying normal fault, as well as the thickness and [...]
Grain friction controls characteristics of seismic cycle in rough faults with granular gouge
Published: 2018-11-02
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Mature faults with rough surface at their core contain granular gouge, however, the presence of fault gouge is mostly disregarded in the analysis of effect of fault’s surface roughness on the mechanics and stability of faults. In this work, we consider a rough fault system with constant roughness at the wall-gouge interaction and study the effect of grain friction on the characteristics of [...]
Overpressure Transfer Through Interconnected Igneous Intrusions
Published: 2018-10-30
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Paper looking at the transference of overpressure through interconnected igneous intrusions within sedimentary basins. The manuscript highlights the current under-recognized hazard in both scientific and hydrocarbon drilling in vicinity of subsurface igneous complexes.
Intermediate-magnitude postseismic slip follows intermediate-magnitude (M 4 to 5) earthquakes in California
Published: 2018-10-29
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The magnitude of postseismic slip is useful for constraining physical models of fault slip. Here we examine the postseismic slip following intermediate-magnitude (M 4 to 5) earthquakes by systematically analyzing data from borehole strainmeters in central and northern California. We assess the noise in the data and identify 36 records from 12 earthquakes that can be interpreted. We estimate [...]