Preprints
Filtering by Subject: Geophysics and Seismology
Double surface rupture and hydraulic recharge of a three-fault system during the Mw 4.9 earthquake of 11 November 2019 at Le Teil (France)
Published: 2022-08-08
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Numerical Analysis and Scientific Computing
The Mw 4.9 earthquake of 11 November 2019 at Le Teil (France) occurred at a very shallow depth (about 1 km) inducing the surface rupture of La Rouvière fault, nearby of a limestone quarry. Thanks to satellite differential interferometry, we detected the existence of the secondary surface rupture of the quasi-parallel Bayne Rocherenard fault. A newly processed seismic cross-section allowed us to [...]
Within the subducting Nazca Plate: The 2020 Mw 6.8 Calama earthquake and its similarity with the surrounding inslab seismicity
Published: 2022-08-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We study the 2020 MW 6.8 Calama earthquake sequence that occurred within the subducting oceanic Nazca plate. The mainshock is modeled via waveform inversion using a dynamic rupture model, while detection and location techniques are used to better characterize its aftershock sequence. We analyze the local seismotectonic and thermal context of the subducting Nazca plate to understand the trigger [...]
Resolving minute temporal seismic velocity changes induced by earthquake damage: The more stations, the merrier ?
Published: 2022-07-29
Subjects: Earth Sciences, Geophysics and Seismology
Ground shaking induced by earthquakes often introduces transient changes in seismic velocity monitored with ambient noise. These changes are usually attributed to relaxation behavior following the co-seismic damage in the subsurface and are of relevance for postseismic hazard mitigation. However, the velocity evolution associated with this phenomenon can occur at very small timescales and [...]
Machine Learning for Elastic-Electrical Cross-Property Modelling Of Sandstones
Published: 2022-07-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Slab to back-arc to arc: fluid and melt pathways through the mantle wedge beneath the Lesser Antilles
Published: 2022-07-14
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Tectonics and Structure, Volcanology
Volatiles expelled from subducted plates melt the overlying warm mantle, feeding arc volcanism. However, debates continue over the factors controlling melt generation and transport and how these determine the placement of volcanoes. To broaden our synoptic view of these fundamental mantle wedge processes, we image seismic attenuation beneath the Lesser Antilles arc, an end-member system that [...]
Comparison of methods for coupled earthquake and tsunami modeling
Published: 2022-07-09
Subjects: Geophysics and Seismology
Tsunami generation by offshore earthquakes is a problem of scientific interest and practical relevance, and one that requires numerical modeling for data interpretation and hazard assessment. Most numerical models utilize two-step methods with one-way coupling between separate earthquake and tsunami models, based on approximations that might limit the applicability and accuracy of the resulting [...]
Seismic interferometry in the presence of an isolated noise source
Published: 2022-07-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Seismic interferometry gives rise to a correlation wavefield that is closely related to the Green's function under the condition of uniformly distributed noise sources. In the presence of an additional isolated noise source, a second contribution to this wavefield is introduced that emerges from the isolated source location at negative lapse time. These two contributions interfere, which may bias [...]
Harnessing Distributed Acoustic Sensing for Earthquake Early Warning: Magnitude Estimation and Ground Motion Prediction
Published: 2022-06-22
Subjects: Geophysics and Seismology
Earthquake Early Warning (EEW) systems provide seconds to tens of seconds of warning time before potentially-damaging ground motions are felt. For optimal warning times, seismic sensors should be installed as close as possible to expected earthquake sources. However, while the most hazardous earthquakes on Earth occur underwater, most seismological stations are located on-land; precious seconds [...]
SAR and InSAR data linked to soil moisture changes on a temperate raised peatland subjected to a wildfire
Published: 2022-06-17
Subjects: Geophysics and Seismology, Hydrology, Soil Science
Interferometry of Synthetic Aperture Radar (InSAR) can potentially contribute to the cost-effective regional or global monitoring of the degradation and restoration of peatlands. However, there are uncertainties about the links between InSAR results and peatland ecohydrological parameters, especially soil moisture. Here, we analyse the relationships between the temporal evolutions of InSAR [...]
Friction law for earthquake nucleation: size doesn’t matter
Published: 2022-06-17
Subjects: Geology, Geophysics and Seismology
A central question in modeling induced and natural earthquake nucleation is whether fault frictional properties measured in the laboratory are applicable to nature. A laboratory fault is generally just a few centimeters in length-width scale, while natural faults can be hundreds of meters to kilometers in extent. It is unknown whether laboratory fault friction data are applicable even to mesh [...]
Advances in seismic imaging of magma and crystal mush
Published: 2022-06-17
Subjects: Earth Sciences, Geophysics and Seismology, Volcanology
Seismic imaging methods have provided detailed three-dimensional constraints on the physical properties of magmatic systems leading to invaluable insight into the storage, differentiation and dynamics of magma. These constraints have been crucial to the development of our modern understanding of magmatic systems. However, there are still outstanding knowledge gaps resulting from the challenges [...]
Visualizing Best and Worst Case Scenarios in Joint, Constrained, and Time-Dependent Inversions I: Null-Space Transfer and Image-Space Contradictions
Published: 2022-05-31
Subjects: Geophysics and Seismology
Because geophysical inversion is used in many vital societal applications, it is unfortunate that some aspects of inverse methods are so abstract. The difficulty of identifying fundamental behaviors is exacerbated when investigating large non-linear problems which combine multiple datasets into a single model, or which produce multiple models with constraints between them. In this first of [...]
Salt-detached strike-slip faulting, Outer Kwanza Basin, Offshore Angola
Published: 2022-05-25
Subjects: Geology, Geophysics and Seismology, Stratigraphy, Tectonics and Structure
We here use a 3D seismic reflection dataset from Outer Kwanza Basin, offshore Angola to examine the structure and growth of salt-detached strike-slip faults. The faults occur in four, up to 13.8 km-long, NE-trending arrays that are physically linked by restraining bend and releasing stepovers, and which presently overlie Aptian salt and base-salt relief related to pre-salt faulting. We suggest [...]
Using Synthetic Data Trained Convolutional Neural Network For Predicting Sub-Resolution Thin Layers From Seismic Data
Published: 2022-05-19
Subjects: Artificial Intelligence and Robotics, Geology, Geophysics and Seismology
Numerous studies have demonstrated the capability of supervised deep learning techniques for predicting geological features of interest from seismic sections, including features that are difficult to identify using traditional interpretation methods. However, successful application of these techniques in practice has been limited by the difficulty of obtaining large training dataset where seismic [...]
Deep Compressed Seismic Learning for fast location and moment tensor inferences with natural and induced seismicity
Published: 2022-05-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Fast detection and characterization of seismic sources is crucial for decision-making and warning systems that monitor natural and induced seismicity. However, besides the laying out of ever denser monitoring networks of seismic instruments, the incorporation of new sensor technologies such as Distributed Acoustic Sensing (DAS) further challenges our processing capabilities to deliver short [...]