Preprints
Filtering by Subject: Geophysics and Seismology
Lithospheric structure and melting processes in southeast Australia: new constraints from joint probabilistic inversions of 3D magnetotelluric and seismic data
Published: 2023-01-24
Subjects: Geology, Geophysics and Seismology
The thermochemical structure of the lithosphere exerts control on melting mechanisms in the mantle as well as the location of volcanism and ore deposits. Imaging the complex interactions between the lithosphere and asthenospheric mantle requires the joint inversion of multiple data sets and their uncertainties. In particular, the combination of seismic velocity and electrical conductivity with [...]
From ground motion simulations to landslide occurrence prediction
Published: 2023-01-17
Subjects: Applied Statistics, Earth Sciences, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Soil Science, Statistical Models, Statistics and Probability
Ground motion simulations solve wave equations in space and time, thus producing detailed estimates of the shaking time series. This is essentially uncharted territory for geomorphologists, for we have yet to understand which ground motion (synthetic or not) parameter, or combination of parameters, is more suitable to explain the coseismic landslide distribution. To address this gap, we developed [...]
A Bayesian Level Set Method for Identifying Subsurface Geometries and Rheological Properties in Stokes Flow
Published: 2023-01-16
Subjects: Earth Sciences, Geophysics and Seismology, Numerical Analysis and Scientific Computing
We aim to simultaneously infer the shape of subsurface structures and material properties such as density or viscosity from surface observations. Modeling mantle flow using incompressible instantaneous Stokes equations, the problem is formulated as an infinite-dimensional Bayesian inverse problem. Subsurface structures are described as level sets of a smooth auxiliary function, allowing for [...]
Mapping glacier basal sliding with machine learning
Published: 2023-01-13
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Geophysics and Seismology
During the RESOLVE project ("High-resolution imaging in subsurface geophysics: development of a multi-instrument platform for interdisciplinary research"), continuous surface displacement and seismic array observations were obtained on Glacier d'Argentière in the French Alps for 35 days in May 2018. The data set is used to perform a detailed study of targeted processes within the highly dynamic [...]
Hillslope recovery after a major earthquake: InSAR-derived time series analyses to capture earthquake-legacy effect
Published: 2022-12-23
Subjects: Geomorphology, Geophysics and Seismology
Mountainous landscapes affected by strong earthquakes exhibit relatively higher landslide susceptibility in post-seismic periods compared to pre-seismic conditions. This concept is referred to as the earthquake legacy effect and is mainly examined by monitoring either rapid landslide occurrences or slow-moving landslides over time. To provide a more comprehensive understanding of the concept, [...]
Return of the Atacama deep Slow Slip Event : the 5-year recurrence confirmed by continuous GPS
Published: 2022-12-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Four years ago, using survey GPS measurements, the first deep slow slip event (SSE) was detected in Chile (near Copiapó, Atacama region), unrelated to any major earthquake. It was located between 40 and 60 km depth on the subduction interface, lasted approximately 18 months (2014-2016.5) and reached an equivalent magnitude of Mw~6.9. The single permanent station operating in the region between [...]
Using foreshocks to constrain earthquake nucleation: low foreshock to aftershock ratios in the Hikurangi subduction zone
Published: 2022-12-19
Subjects: Geophysics and Seismology
The complexity and duration of earthquake nucleation is an open question. Our understanding of this process is limited by a lack of high-quality observations of foreshocks and aftershocks. We therefore apply a coherence-based template matching approach to search for more foreshocks and aftershocks. We examine the half-hour before thousands of M3+ mainshocks on the Hikurangi subduction zone in New [...]
Re-examining Temporal Variations in Intermediate-Depth Seismicity
Published: 2022-12-16
Subjects: Geophysics and Seismology
Changes in the frequency of intermediate-depth (60–300 km) earthquakes in response to static stress transfer can provide insights into the mechanisms of earthquake generation within subducting slabs. In this study, we use the most up-to-date global and regional earthquake catalogues to show that both the aftershock productivity of large earthquakes, and the changes in the frequency of [...]
Modeling Earthquake-induced Landslide initiation using the Fibre Bundle Model
Published: 2022-12-05
Subjects: Geology, Geomorphology, Geophysics and Seismology, Hydrology
Co-seismic landslides are triggered by strong ground shaking in mountainous areas, resulting in threats to human activity and infrastructure. Methods for physically-based modelling of co-seismic landslide triggering play an important role in disaster prevention and mitigation. Current approaches, however, focus on direct and full failure of sloping rocks and soils, and do not cover the dynamics [...]
The effect of uncertainties in creep activation energies on modeling ice flow and deformation
Published: 2022-11-21
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics
Ice deformation is commonly represented by a power-law constitutive relation, Glen's Flow Law, where deformation (strain) rate equals stress raised to the power n and multiplied by a flow-rate parameter A. Glen's Law represents bulk ice rheology as a single power-law even though multiple mechanisms, each with their own power-law relation and parametric values, act together during viscous [...]
Lithospheric structure and melting processes in southeast Australia: new constraints from joint probabilistic inversions of 3D magnetotelluric and seismic data
Published: 2022-11-18
Subjects: Geochemistry, Geophysics and Seismology, Volcanology
The thermochemical structure of the lithosphere exerts control on melting mechanisms in the mantle as well as the location of volcanism and ore deposits. Imaging the complex interactions between the lithosphere and asthenospheric mantle requires the joint inversion of multiple data sets and their uncertainties. In particular, the combination of seismic velocity and electrical conductivity with [...]
How reproducible and reliable is geophysical research? A review of the availability and accessibility of data and software for research published in journals
Published: 2022-11-17
Subjects: Earth Sciences, Geophysics and Seismology, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Other Earth Sciences, Physical Sciences and Mathematics, Sustainability
Geophysical research frequently makes use of agreed methodologies, formally published software, and bespoke code to process and analyse data. The reliability and repeatability of these methods is vital in maintaining the integrity of research findings and thereby avoiding the dissemination of unreliable results. In recent years there has been increased attention on aspects of reproducibility, [...]
Evolution of intraplate magmatism atop a mantle plume: geochemical and chronological analysis of Shawahit Basalt, Harrat Rahat, Saudi Arabia
Published: 2022-11-15
Subjects: Earth Sciences, Geology, Geomorphology, Geophysics and Seismology, Stratigraphy, Tectonics and Structure, Volcanology
Harrat Rahat is the largest volcanic eld in Saudi Arabia and has been active from ~10 Ma to the present day. Due to its close proximity to important population centres, Harrat Rahat's recent eruptions, the Medinah lava flows (< 1.7 Ma), have been extensively studied to identify volcanic risk. However, the evolution of Harrat Rahat's most extensive and oldest lava flows, known collectively as the [...]
Seismic Architecture of the Lithosphere-Asthenosphere System in the Western United States from a Joint Inversion of Body- and Surface-wave Observations: Distribution of Partial Melt in the Upper Mantle
Published: 2022-11-08
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Quantitative evaluation of the physical state of the upper mantle, including mapping temperature variations and the possible distribution of partial melt, requires accurately characterizing absolute seismic velocities near seismic discontinuities. We present a joint inversion for absolute but discontinuous models of shear-wave velocity (Vs) using 4 types of data: Rayleigh wave phases velocities, [...]
Tectonics is a hologram
Published: 2022-11-05
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
A hologram is an image in which each area contains almost all the information about the entire system. It is a metaphor commonly used for complex systems in which the whole is bigger than the sum of the parts because of self-organization. And also the whole is smaller than the sum of the parts, since the collective organization limits the behavior of dynamic features. The tectonic evolution of [...]