Preprints
Search for earthquake (513 results)
The 2020 Mw 6.5 Monte Cristo Range, Nevada earthquake: relocated seismicity shows rupture of a complete shear-crack system
Published: 2020-12-18
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Tectonics and Structure
The predominant model for earthquake faulting is a shear crack, including surrounding damage zones. Observation of this complete shear crack system at seismogenic depth, however, has been elusive. Shear cracks with damage zones are related to fault formation and growth, and earthquake rupture physics and size, but observational and analytical limitations impede use of the shear crack paradigm in [...]
Bookshelf Kinematics and the Effect of Dilatation on Fault Zone Inelastic Deformation: Examples from Optical Image Correlation Measurements of the 2019 Ridgecrest Earthquake Sequence
Published: 2020-12-17
Subjects: Physical Sciences and Mathematics
The 2019 Ridgecrest earthquake sequence initiated on July 4th with a series of foreshocks, including a Mw 6.4 event, that culminated a day later with the Mw 7.1 mainshock and resulted in rupture of a set of cross-faults. Here we use sub-pixel correlation of optical satellite imagery to measure the displacement, finite strain and rotation of the near-field coseismic deformation to understand the [...]
Global models for short-term earthquake forecasting and predictive skill assessment
Published: 2020-12-16
Subjects: Physical Sciences and Mathematics
We present rigorous tests of global short-term earthquake forecasts using Epidemic Type Aftershock Sequence models with two different time kernels (one with exponentially tapered Omori kernel (ETOK) and another with linear magnitude dependent Omori kernel (MDOK)). The tests are conducted with three different magnitude cutoffs for the auxiliary catalog (M3, M4 or M5) and two different magnitude [...]
Initial model construction for intermediate-period full-waveform inversion of the contiguous US and surrounding regions
Published: 2020-12-15
Subjects: Geophysics and Seismology
Contiguous US is one of regions well instrumented with broadband seismic stations due to the deployment of the EarthScope Transportable Array. Previous studies have provided various 3D seismic wave speed models for the crust and upper mantle with improving resolution. However, discrepancies exist between these models due to the differences in both data sets and tomographic methods, which [...]
Anatomy of Strike Slip Fault Tsunami-genesis
Published: 2020-12-13
Subjects: Earth Sciences, Engineering, Fluid Dynamics, Geophysics and Seismology, Physical Sciences and Mathematics, Physics
Tsunami generation from earthquake induced seafloor deformations has long been recognized as a major hazard to coastal areas. Strike-slip faulting has generally been believed as insufficient for triggering large tsunamis, except through the generation of submarine landslides. Herein, we demonstrate that ground motions due to strike-slip earthquakes can contribute to the emergence of large [...]
Mapping Landslides With a Generalized Convolutional Neural Network
Published: 2020-12-13
Subjects: Geomorphology, Other Earth Sciences, Risk Analysis
Landslides are a common secondary hazard triggered by major earthquakes or extreme rainfall events in steep terrains. Rapid mapping of event landslides is crucial to identify the areas affected by damages as well as for effective disaster response. Traditionally, such maps are generated with visual interpretation of remote sensing imagery (manned/unmanned airborne systems or spaceborne sensors) [...]
Recording earthquakes for tomographic imaging of the mantle beneath the South Pacific by autonomous MERMAID floats
Published: 2020-12-02
Subjects: Geophysics and Seismology
We present the first 16 months of data returned from a mobile array of 16 freely floating diving instruments, named MERMAID for Mobile Earthquake Recording in Marine Areas by Independent Divers, launched in French Polynesia in late 2018. Our 16 are a subset of the 50 MERMAID deployed over a number of cruises in this vast and understudied oceanic province as part of the collaborative South Pacific [...]
Cascadia megathrust earthquake rupture model constrained by geodetic fault locking
Published: 2020-11-30
Subjects: Earth Sciences
Paleo-earthquakes along the Cascadia subduction zone inferred from offshore sediments and Japan coastal tsunami deposits approximated to M9+ and ruptured the entire margin. However, due to the lack of modern megathrust earthquake records and generally quiescence of subduction fault seismicity, the potential megathrust rupture scenario and influence of downdip limit of the seismogenic zone are [...]
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 [...]
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 [...]
Microseismicity appears to outline highly coupled regions on the Central Chile megathrust
Published: 2020-11-12
Subjects: Physical Sciences and Mathematics
We compiled a novel microseismicity catalog for the Central Chile megathrust (29-35◦S), comprising 8750 earthquakes between 04/2014 and 12/2018. These events describe a pattern of three trenchward open half-ellipses, consisting of a continuous, coast-parallel seismicity band at 30-45 km depth, and narrow elongated seismicity clusters that protrude to the shallow megathrust and separate largely [...]
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 [...]