Preprints
Filtering by Subject: Geophysics and Seismology
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 [...]
Initiation and Arrest of Earthquake Ruptures due to Elongated Overstressed Regions
Published: 2018-10-23
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The initiation of natural and induced earthquakes is promoted in fault areas where the shear stress is close to fault strength. In many important situations, these overstressed fault areas (or “asperities”) are very elongated; for example, in the case of a fault intersecting a reservoir subject to fluid-injection, or the stress concentration along the bottom of a seismogenic zone induced by deep [...]
An Evaluation between Time-term, Reciprocal Time and Refraction Tomography Analysis Methods for obtaining 2-D shallow Seismic Velocity Models over Synthetic Traveltimes
Published: 2018-10-22
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Shallow seismic refraction is the principal geophysical method for environmental and engineering site investigations to image the shallow subsurface. We present an assessment of three inversion methods, namely Time-Term inversion, Reciprocal Time methods and Refraction tomography inversion by using commercial software (SeisImager™) by using a synthetic first-arrival-time dataset that was made by [...]
Disruption of Long-Term Effusive-Explosive Activity at Santiaguito, Guatemala
Published: 2018-10-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Rapid transitions in eruptive activity during lava dome eruptions pose significant challenges for monitoring and hazard assessment efforts. A comprehensive understanding of the dynamic evolution of active lava dome systems requires extensive multi-parametric datasets to fully constrain and understand rapid shifts in eruptive behavior, but few such datasets have been compiled. The Santiaguito lava [...]
Wavelet-based analysis of ground deformation coupling satellite acquisitions (Sentinel-1, SMOS) and data from shallow and deep wells in Southwestern France
Published: 2018-10-15
Subjects: Aerospace Engineering, Applied Mathematics, Earth Sciences, Engineering, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics
Acquisitions of the Sentinel-1 satellite are processed and comprehensively analyzed to investigate the ground displacement during a 3-year period above a gas storage site in Southwestern France. Despite quite low vertical displacements (between 4 and 8 mm) compared to the noise level, the local displacements reflects the variations due to charge and discharge during summer and winter periods, [...]
Seismic observation of tsunami at island broadband stations
Published: 2018-10-15
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Previous studies have reported seismic observations of tsunami recorded at island broadband stations. Coastal loading by the tsunami can explain them. For further quantification, we model tsunami propagation assuming an axisymmetric structure: a conical island with a flat ocean floor. The total tsunami wavefield can be represented by superposition between an incident tsunami wave and the [...]
High-temperature shear zone formation in Carrara marble: The effect of loading conditions
Published: 2018-09-26
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Rock deformation at depths in the Earth’s crust is often localized in high temperature shear zones occurring at different scales in a variety of lithologies. The presence of material heterogeneities is known to trigger shear zone development, but the mechanisms controlling initiation and evolution of localization are not fully understood. To investigate the effect of loading conditions on shear [...]
Complex and cascading triggering of submarine landslides and turbidity currents at volcanic islands revealed from integration of high-resolution onshore and offshore surveys
Published: 2018-09-22
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
Submerged flanks of volcanic islands are prone to hazards including submarine landslides that may trigger damaging tsunamis and fast-moving sediment-laden seafloor flows (turbidity currents) that break critical seafloor infrastructure. Small Island Developing States are particularly vulnerable to these hazards due to their remote and isolated nature, small size, high population densities and weak [...]
Earthquake early warning using future generation gravity strainmeters
Published: 2018-09-14
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Recent studies reported the observation of prompt elastogravity signals during the 2011 M9.1 Tohoku earthquake, recorded with broadband seismometers and gravimeter between the rupture onset and the arrival of the seismic waves. Here we show that to extend the range of magnitudes over which the gravity perturbations can be observed and reduce the time needed for their detection, high-precision [...]
Earthquake Swarms and Slow Slip on a Sliver Fault in the Mexican Subduction Zone
Published: 2018-08-24
Subjects: Earth Sciences, Geophysics and Seismology, Life Sciences, Physical Sciences and Mathematics
The Mexican Subduction Zone is an ideal location for studying subduction processes due to the short trench-to-coast distances that bring broad portions of the seismogenic and transition zones of the plate interface inland. Using a recently generated seismicity catalog from a local network in Oaxaca, we identified 20 swarms of earthquakes (M<5) from 2006-2012. Swarms outline what appears to be [...]
Controls of basement fabric on rift coupling and development of normal fault geometries: Insights from the Rukwa – North Malawi Rift
Published: 2018-08-19
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The Rukwa Rift and North Malawi Rift Segments (RNMRS) both define a major rift-oblique segment of the East African Rift System (EARS), and although the two young rifts show colinear approaching geometries, they are often regarded as discrete rifts due to the presence of the intervening Mbozi Block uplift located in-between. This problem has been complicated by the dominance of the Rungwe volcanic [...]