Preprints
Filtering by Subject: Geophysics and Seismology
Double-difference earthquake relocation using waveform cross-correlation in Central and East Java, Indonesia (Preprint)
Published: 2020-11-25
Subjects: Earth Sciences, Geophysics and Seismology
The Central and East Java region, which is part of the Sunda Arc, has relatively high seismic rates due to the convergence of two major tectonic plates in the Indonesian region; i.e., the Indo-Australian Plate subducting under the Eurasian Plate. Many devastating earthquakes have occurred in this area as a result of the interaction between these two plates. Two examples are the 1994 Banyuwangi [...]
Deformation memory in the lithosphere: A comparison of damage-dependent weakening and grain-size sensitive rheologies
Published: 2020-11-25
Subjects: Earth Sciences, Geophysics and Seismology
Strain localization in the lithosphere and the formation, evolution, and maintenance of resulting plate boundaries play a crucial role in plate tectonics and thermo-chemical mantle convection. Previously activated lithospheric deformation zones often appear to maintain a “memory” of weakening, leading to tectonic inheritance within plate reorganizations including the Wilson cycle. Different [...]
Rare occurrences of non-cascading foreshock activity in Southern California
Published: 2020-11-20
Subjects: Geophysics and Seismology
Earthquakes preceding large events are commonly referred as foreshocks. They are often considered as precursory signals reflecting the nucleation process of the main rupture. Such foreshock sequences may also be explained by cascades of triggered events. Recent advances in earthquake detection is a motivation to re-evaluate seismicity variations prior to mainshocks. Based on a highly complete [...]
Mantle earthquakes in recently thinned Neoproterozoic lithosphere: Harrat Lunayyir, Saudi Arabia
Published: 2020-11-20
Subjects: Geophysics and Seismology, Tectonics and Structure
We use earthquake geothermometry, measured heat flow, and structural constraints from P-wave receiver functions to model the thermal evolution of the lithosphere beneath Harrat Lunayyir. We suggest that the lithosphere thinned to its present 60-km thickness in a second stage of lithospheric thinning at 15–12 Ma following initial Red Sea extension at ~27 Ma. Harrat Lunayyir is an active volcanic [...]
Future magnitude 7.5 earthquake offshore Martinique: Spotlight on the main source features controlling ground motion prediction
Published: 2020-11-18
Subjects: Civil and Environmental Engineering, Geophysics and Seismology, Geotechnical Engineering
The eastern offshore of Martinique is one of the active areas of the Lesser Antilles Subduc tion Zone (LASZ). Although its seismicity is moderate compared to other subduction zones, LASZ is capable of generating a M 7+ interplate earthquake and recent studies and historical events, such as the M8 1839 and M 7-7.5 1946 earthquakes, confirm this possibility. Given the high risk that Martinique can [...]
International Meeting 40 years of the 1980 Azores Earthquake, 6th - 7th October 2020 - Conference Report
Published: 2020-11-16
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Geophysics and Seismology, Other Civil and Environmental Engineering
The main goal of the International Meeting “40 Years of the 1980 Azores Earthquake” was promoting a reflection of the earthquake of January 1st, 1980, and the advances since them on topics like seismology, seismic hazard, and risk, building rehabilitation and public policies. Nevertheless, due to the COVID-19 outbreak, the organizing committee decided that the meeting should be online and [...]
On the use of rock physics models for studying the critical zone
Published: 2020-11-12
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology
How effective are rock physics models for relating seismic velocities to the physical properties of sediments, fluids, and cement within the critical zone, and what factors most substantially influence the models’ accuracies? We answer these questions by testing and analyzing the accuracies of seven rock physics models (Hertz-Mindlin, Walton, Jenkins, Digby, stiff sand, soft sand, and contact [...]
The effects of 180 years of aging on the physical and seismic properties of partially saturated sands
Published: 2020-11-12
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology
Constraining how the physical properties and seismic responses of recently deposited sands change with time is important for understanding earthquake site response, subsurface fluid flow, and early stages lithification. Currently, however, there is no detailed (cm-scale) assessment of how sand physical properties and associated seismic velocities evolve over the first two centuries after [...]
Utilizing Distributed Acoustic Sensing and Ocean Bottom Fiber Optic Cables for Submarine Structural Characterization
Published: 2020-11-09
Subjects: Geophysics and Seismology, Oceanography
The sparsity of permanent seismic instrumentation in marine environments often limits the availability of subsea information on geohazards, including active fault systems, in both time and space. One sensing resource that may provide observational access to the seafloor environment are existing networks of ocean bottom fiber optic cables; these cables, coupled to modern distributed acoustic [...]
An attempt at improving atmospheric corrections in InSAR using cycle-consistent adversarial networks
Published: 2020-11-09
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Geophysics and Seismology
Interferometry from satellite radar has thrived as a major asset to study surface deformations from earthquakes, volcanoes, aquifers, glaciers, landslides, etc. Most signals recorded in an interferogram have precise enough models to remove them almost completely. Yet, current models still fail to capture the full range and scales of variations of atmospheric perturbations. This work explores the [...]
Surface slip distributions and geometric complexity of intraplate reverse-faulting earthquakes
Published: 2020-11-09
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Earthquake ground surface ruptures provide insights into faulting mechanics and inform seismic hazard analyses. Surface ruptures for eleven historical (1968 to 2018) moment magnitude (Mw) 4.7 to 6.6 reverse earthquakes in Australia are analyzed using statistical techniques and compared to magnetic, gravity, and stress trajectory datasets. Of the total combined (summative) length of all surface [...]
Thickness of the Saudi Arabian Crust
Published: 2020-11-05
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
We analyzed P-wave receiver functions from seismic stations covering most of Saudi Arabia to map the thickness of the crust across the Arabian plate. We present an update of crustal-thickness estimates and fill in data gaps for the western shield and the rifted margin at the Red Sea, as well as the eastern Arabian platform. Our application of a conventional H-k stacking algorithm included [...]
Influence of ductile substrates and layer thickness on the spacing and topology of layer bound fault systems
Published: 2020-11-02
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Sedimentology, Tectonics and Structure
Polygonal fault systems are extraordinary features of many fine grained sedimentary succession and have been described from a significant number of deepwater sedimentary basins over the last two decades. Their formation represents an important mechanism by which fine grained sediments compact often resulting in a variety of complex patterns for which several controlling factors have been [...]
Rayleigh wave H/V ratio measurement from ambient noise cross-correlations, and its sensitivity to Vp: a numerical study
Published: 2020-10-30
Subjects: Earth Sciences, Geophysics and Seismology
The promise of passive seismology has increasingly been realized in recent years. Given the expense in installing and maintaining seismic station networks, it is important to extract as much information from the measurements as possible. In this context, the ellipticity or H/V amplitude ratio of Rayleigh waves can prove to be a valuable observable in ambient noise seismology due to its [...]
High-frequency global wavefields for local 3D structures by wavefield injection and extrapolation
Published: 2020-10-28
Subjects: Geophysics and Seismology
Earth structure is multiscale, and seismology remains the primary means of deciphering signatures from small structures over large distances. To enable this at the highest resolution, we present a flexible injection and extrapolation type hybrid framework that couples wavefields from a precomputed global database of accurate Green’s functions with a local three dimensional (3-D) method of [...]