Preprints
Search for earthquake (513 results)
Complex and confined laboratory ruptures explain scaling of the critical slip distance for earthquake faulting
Published: 2024-08-22
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Earthquake sequences in nature are complex, exhibiting a range of magnitudes and slip behaviors. In contrast, earthquake-like instabilities generated on frictional faults in the laboratory and in continuum numerical models are usually quasi-periodic with a smaller range of magnitudes and durations. The discrepancy, especially apparent for cm-sized samples used in lab friction experiments, has [...]
Partial ruptures governed by the complex interplay between geodetic slip deficit, rigidity, and pore fluid pressure in 3D Cascadia dynamic rupture simulations
Published: 2024-08-14
Subjects: Geophysics and Seismology
Physics-based simulations are crucial to assessing the seismic hazard in the Cascadia subduction zone (CSZ), requiring assumptions about fault stress and material properties. Geodetic slip deficit models (SDMs) may inform the initial stresses governing megathrust earthquake dynamics. We present a unified workflow linking SDMs to 3D dynamic rupture simulations, and 22 rupture scenarios to unravel [...]
Denoising Daily Displacement GNSS-Time series using Deep Neural Networks In a Near Real-Time Framing: a Single-Station Method
Published: 2024-08-05
Subjects: Earth Sciences
Recent ground observations from Global Navigation Satellite Systems (GNSS) displacement time series have provided compelling evidence that the motion of tectonic plates is ubiquitously non-steady-state. In some cases, these anomalous transient motions have been identified as potential precursors occurring months, days, or hours before large-magnitude earthquakes. However, effectively detecting [...]
The first seismo-volcanological observatory on Montserrat
Published: 2024-07-27
Subjects: Physical Sciences and Mathematics
The first seismo-volcanological observatory in the anglophone Caribbean was established on Montserrat in 1936, in response to a volcano-seismic crisis that began in in 1933. Staff at Montserrat’s agricultural office began routinely observing earthquake shocks in 1934. In 1936, following a scientific expedition dispatched by the Royal Society, an observatory was established at the Grove Botanical [...]
Towards automatic delineation of landslide source and runout
Published: 2024-07-26
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Mathematics
Mapping landslide-depleted source areas is pivotal for refining predictive models and volume estimations, yet these critical regions are often conflated with the landslide runouts, leading to sub-optimal assessments. The source areas are typically the regions where the actual failure occurs, providing crucial information on the initiation mechanisms and the nature of landslide propagation. [...]
Ground Motion Characteristics of Subshear and Supershear Ruptures in the Presence of Sediment Layers
Published: 2024-07-19
Subjects: Engineering, Physical Sciences and Mathematics
We investigate the impact of sediment layers on ground motion characteristics during subshear and supershear rupture growth. Our findings suggest that sediment layers may lead to local supershear propagation, affecting ground motion, especially in the fault parallel (FP) direction. In contrast to homogeneous material models, we find that in the presence of sediment layers, a larger fault normal [...]
Rupture directivity from energy envelope deconvolution: theory and application to 69 Ridgecrest M 3.5–5.5 earthquakes
Published: 2024-07-13
Subjects: Geophysics and Seismology
Earthquake rupture directivity impacts ground motions and provides important insights on fault zone properties and earthquake physics. However, measuring directivity of small earthquakes is challenging due to their compact rupture sizes and complex path and site effects at high frequencies. Here, we develop a new approach that deconvolves energy envelopes of the S-coda waves to remove path and [...]
Quantifying relationships between fault parameters and rupture characteristics associated with thrust and reverse fault earthquakes.
Published: 2024-07-12
Subjects: Geology, Geomorphology, Geophysics and Seismology, Geotechnical Engineering, Risk Analysis, Tectonics and Structure
We investigate the influence of earthquake source characteristics and geological site parameters on fault scarp morphologies for thrust and reverse fault earthquakes using geomechanical models. We performed a total of 3,434 distinct element method (DEM) model experiments to evaluate the impact of the sediment depth, density, homogeneous and heterogeneous sediment strengths, fault dip, and the [...]
Fast and full characterization of large earthquakes from prompt elastogravity signals
Published: 2024-07-11
Subjects: Geophysics and Seismology
Prompt ElastoGravity Signals (PEGS) are light-speed gravity-induced signals recorded by seismometers before the arrival of seismic waves. They have raised interest for early warning applications but their weak amplitudes, close to the background seismic noise even for large earthquakes, have questioned PEGS actual potential for operational use. A deep-learning model has recently demonstrated its [...]
Interplay of slow-slip faults beneath Mexico City induces intense seismicity over months
Published: 2024-07-10
Subjects: Physical Sciences and Mathematics
In February 2023, a long seismic sequence began in western Mexico City causing widespread panic and some damage to housing infrastructure. On May 11 and December 14, two Mw3.2 mainshocks occurred at less than 700 m depth. Unprecedented satellite interferograms captured tectonic deformations in the two epicentral zones during the days surrounding the earthquakes. Data analysis revealed extended [...]
Dynamic Rupture Modeling in a Complex Fault Zone with Distributed and Localized Damage
Published: 2024-06-28
Subjects: Physical Sciences and Mathematics
Active fault zones have complex structural and geometric features that are expected to affect earthquake nucleation, rupture propagation with shear and volumetric deformation, and arrest. Earthquakes, in turn, dynamically activate co-seismic off-fault damage that may be both distributed and localized, affecting fault zone geometry and rheology, and further influencing post-seismic deformation and [...]
Implementation of the Peruvian Earthquake Early Warning System
Published: 2024-06-12
Subjects: Artificial Intelligence and Robotics, Geophysics and Seismology
We present the implementation and testing of the seismological components of the Peruvian Earthquake Early Warning System (Sistema de Alerta Sísmica Peruano, SASPe). SASPe is designed to send alert messages to areas located within a given distance from the epicenter of large (magnitude ≥ 6.0) subduction earthquakes, with a first alert based on data available 3 seconds after the arrival [...]
Do large earthquakes start with a precursory phase of slow slip?
Published: 2024-06-06
Subjects: Geophysics and Seismology
In a recent publication, we showed that a stack of all GPS time series recorded before Magnitude ≥ 7.0 earthquakes suggests that large earthquakes start with a precursory phase of accelerating slow slip (Bletery and Nocquet, 2023). While no peer-reviewed comment or publication has formally contradicted this result, informal discussion has emerged on various platforms. We present here the [...]
Ensemble Kalman, Adaptive Gaussian Mixture, and Particle Flow Filters for Optimized Earthquake Forecasting
Published: 2024-06-01
Subjects: Dynamical Systems, Geophysics and Seismology, Other Statistics and Probability
Probabilistic forecasts are regarded as the highest achievable goal when predicting earthquakes, but limited information on stress, strength, and governing parameters of the seismogenic sources affects their accuracy. Ensemble data-assimilation methods, such as the Ensemble Kalman Filter (EnKF), estimate these variables by combining physics-based models and observations.While the EnKF has [...]
Ringing mountain ranges: Teleseismic signature of the interaction of high-frequency wavefields with near-source topography at the Degelen nuclear test site
Published: 2024-05-26
Subjects: Geophysics and Seismology
Over the last decade there has been an international effort to find methods to recover and digitize recordings from historical earthquakes and explosions that occurred during the 1950’s through to the 1980’s. Making these recordings accessible in digital format offers opportunities to study what signatures are encoded in the data, and to apply state-of-the-art techniques and methods to historical [...]