Preprints
Search for earthquake (502 results)
Sediment Corrections for Distributed Acoustic Sensing
Published: 2024-03-06
Subjects: Physical Sciences and Mathematics
On continental margins, sediments cause significant and spatially variable delays in seismic phase arrival times. The strong impedance contrast of the sediment-bedrock interface causes P-wave splitting that is clearly seen on Distributed Acoustic Sensing recordings of earthquakes, resulting in additional phase arrivals that must be picked separately. We introduce sediment corrections to correctly [...]
The effects of precursory velocity changes on earthquake nucleation and stress evolution in dynamic earthquake cycle simulations
Published: 2024-02-21
Subjects: Physical Sciences and Mathematics
Seismic velocity changes in earthquake cycles have been observed over a wide range of timescales and may be a good indicator of the onset of future earthquakes. Understanding the effects of precursory velocity changes right before seismic and slow-slip events could potentially elucidate the onset and timing of fault failure. We use numerical models to simulate fully dynamic earthquake cycles in [...]
Mechanisms and seismological signatures of rupture complexity induced by fault damage zones in fully-dynamic earthquake cycle models
Published: 2024-02-10
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Physical Sciences and Mathematics
Damage zones are common around faults, but their effects on earthquake mechanics are still incompletely understood. Here, we investigate how damage affects rupture patterns, source time functions and ground motions in 2D fully-dynamic cycle models. We find that back-propagating rupture fronts emerge in large faults and can be triggered by residual stresses left by previous ruptures or by [...]
Azimuthal Variation in the Spectra of the 2019 Ridgecrest Earthquake Clusters and its Application to Understanding Fault Zone Structure
Published: 2024-02-08
Subjects: Physical Sciences and Mathematics
We first show through dynamic rupture models that FDZs can amplify high-frequency waves along directions close to fault strike and the amplified frequency band may be used to estimate the width and velocity contrast of the FDZ. Then, we identify this high-frequency amplification in the spectra of M1.5–3 earthquakes from the 2019 Ridgecrest earthquake sequence. We cluster the earthquakes by [...]
Possible Mechanisms for Tsunami-like Surge Deposits Due to the Chicxulub Impact at the K-Pg Boundary at the Tanis Site, North Dakota
Published: 2024-02-02
Subjects: Physical Sciences and Mathematics
At Tanis, a unique bi-directional sediment package occurs precisely at the Cretaceous-Paleogene (KPg) boundary, recording the first hours of the Paleogene in uncommonly fine temporal detail. The impact ejecta-bearing sediment package was rapidly emplaced by two massive, ~10-meter-high, potentially impact-triggered surges, that inundated a steep, deeply incised paleo river valley from the [...]
Distributed Acoustic Sensing for aftershock monitoring: the case of the 2019 Mw 4.9 Le Teil earthquake
Published: 2024-01-30
Subjects: Geophysics and Seismology
Recent developments in Distributed Acoustic Sensing (DAS) have greatly expanded our capabilities for dense geophysical instrumentation by tapping into existing (but unused) fibre-optic telecommunication networks. Leveraging these so-called "dark fibres" permits an extremely rapid deployment of thousands of vibration sensors over distances of several tens of kilometres, which is ideal for rapid [...]
Unsupervised Structural Damage Assessment from Space using the Segment Anything Model (USDA-SAM): A Case Study of the 2023 Türkiye Earthquake
Published: 2024-01-23
Subjects: Computer Sciences, Earth Sciences, Engineering, Environmental Sciences
This paper explores advanced deep learning methods, specifically utilising the Segment Anything Model (SAM) along with image processing techniques, to evaluate the structural damages caused by the devastating earthquake that occurred in Turkey on February 6, 2023. Leveraging exceptionally high-resolution pre- and post-disaster imagery provided by Maxar Technologies, this paper showcases the [...]
Transient aseismic vertical deformation across the Pisia-Skinos normal fault (Gulf of Corinth, Greece)
Published: 2024-01-18
Subjects: Earth Sciences, Geophysics and Seismology, Tectonics and Structure
Geodetically-derived deformation rates are sometimes used to infer seismic hazard, implicitly assuming that short-term (annual-decadal) deformation is representative of longer-term deformation. This is despite geological observations indicating that deformation/slip rates are variable over a range of timescales. Using geodetic data from 2016-2021, we observe an up to 7-fold increase in vertical [...]
The Effects of Characteristic Slip Distance on Earthquake Nucleation Styles in Fully Dynamic Seismic Cycle Simulations
Published: 2024-01-17
Subjects: Earth Sciences, Geophysics and Seismology
Earthquake nucleation is a crucial preparation process of the following coseismic rupture propagation. Under the framework of rate-and-state friction (RSF), it was found that the ratios of a to b parameters control whether earthquakes nucleate as an expanding crack or a fixed length. However, the characteristic slip distance DRS controls the weakening efficiency of fault strength and can [...]
Fast relocking and afterslip-seismicity evolution following the 2015 Mw 8.3 Illapel earthquake in Chile
Published: 2024-01-16
Subjects: Physical Sciences and Mathematics
Large subduction earthquakes induce complex postseismic deformation, primarily driven by afterslip and viscoelastic relaxation, in addition to interplate relocking processes. However, these signals are intricately intertwined, posing challenges in determining the timing and nature of relocking. Here, we use six years of continuous GNSS measurements (2015-2021) to study the spatio-temporal [...]
B-value variations in the Central Chile seismic gap assessed by a Bayesian transdimensional approach
Published: 2024-01-15
Subjects: Physical Sciences and Mathematics
The b-value can be used to characterize the seismic activity for a given earthquake catalog and provide information on the stress level accumulated at active faults. Here we develop an algorithm to objectively estimate variations of b-value along one arbitrary dimension. To this end, we employ a Bayesian transdimensional approach where the seismic domains will be self-defined according to [...]
The Northern Chile forearc constrained by 15 years of permanent seismic monitoring
Published: 2024-01-12
Subjects: Physical Sciences and Mathematics
In this review article, we compile seismological observations from the different constituent parts of the Northern Chile forearc: the downgoing Nazca Plate, the plate interface, the upper South American Plate as well as the mantle wedge beneath it. As Northern Chile has been monitored by a network of permanent seismic stations since late 2006, there is a wealth of observations that enables us to [...]
Megathrust locking encoded in subduction landscapes
Published: 2024-01-04
Subjects: Physical Sciences and Mathematics
Locked areas of subduction megathrusts are increasingly found to coincide with landscape features sculpted over hundreds of kyrs, yet the mechanisms that underlie such correlations remain elusive. We show that interseismic locking gradients induce increments of irreversible strain across the overriding plate manifested predominantly as distributed seismicity. Summing these increments over [...]
A shake and a surge: Assessing the possibility of an earthquake-triggered eruption at Steamboat Geyser
Published: 2024-01-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
When and why earthquakes trigger volcano and geyser eruptions remains unclear. In September 2022, Steamboat Geyser in Yellowstone, USA erupted 8.25 hours after a local M3.9 earthquake—an improbable coincidence based on the geyser’s eruption intervals. We leverage monitoring data from the surrounding geyser basin to determine if the earthquake triggered this eruption. We calculate a peak ground [...]
Investigation of Liquefaction Potential in Sands Mixed with Gravel
Published: 2023-12-21
Subjects: Engineering
Liquefaction is one of the significant hazards associated with earthquakes. It was previously believed to occur mostly in clean sands; however, recent research has shown that liquefaction can occur in specific conditions in sands mixed with fine or coarse particles. Numerous studies have been conducted on clean sand, while limited research has focused on sands mixed with silt. Nevertheless, the [...]