Preprints
Filtering by Subject: Geophysics and Seismology
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: 2022-11-20
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: 2022-11-04
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 [...]
The Seismic Signature of California's Earthquakes, Droughts, and Floods
Published: 2022-11-03
Subjects: Geophysics and Seismology
his study investigates changes in seismic velocities in the period 1999-2021 using about 700 permanent and temporary broadband seismic stations in the state of California. We compute single-station cross-correlations of the ambient seismic noise and use the coda-wave interferometry to measure the changes in seismic velocities ({\it dv/v}) using a stretching technique. We focus on the 2-4Hz [...]
Impact of Deccan Volcanism on Reorganization of the Indian plate kinematics
Published: 2022-10-29
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure
Western Indian Ocean basin shows one of the most complex signatures of the ocean floor anomalies by juxtaposition of the rapidly evolving, multiple spreading ridges, subduction systems and microcontinental slivers. This study based on ocean floor magnetic anomalies, gravity gradient map, tomographic profiles and geometrical kinematic models reports a significant westward drift of the Central [...]
Spatial variation in shallow slow earthquake activity in Hyuga-nada, southwest Japan
Published: 2022-10-28
Subjects: Geophysics and Seismology
Hyuga-nada, off the Pacific coast of Kyushu along the Nankai Trough in southwest Japan, is one of the most active slow earthquake regions around Japan. We estimated the energies of shallow tremors and moments of shallow very low frequency earthquakes (VLFEs) in Hyuga-nada using data from a permanent onshore broadband network and temporary ocean bottom seismometer observations. The energies and [...]
GANSim-surrogate: An integrated framework for conditional geomodelling and uncertainty analysis
Published: 2022-10-24
Subjects: Computational Engineering, Earth Sciences, Environmental Engineering, Fluid Dynamics, Geology, Geophysics and Seismology, Hydrology, Sedimentology
We propose a deep-learning framework (GANSim-surrogate) for conditioning subsurface geomodel realizations to static data and dynamic flow data. The static data includes well facies data, interpreted facies probability maps, and non-spatial global features, while dynamic data can include well data such as pressures and flow rates. The framework consists of a Convolutional Neural Network (CNN) [...]
Fault Friction Derived from Fault Bend Influence on Coseismic Slip During the 2019 Ridgecrest Mw 7.1 Mainshock
Published: 2022-10-18
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The variation of stress on faults is important for our understanding of fault friction and the dynamics of earthquake ruptures. However, we still have little observational constraints on their absolute magnitude, or their variations in space and in time over the seismic cycle. Here we use a new geodetic imaging technique to measure the 3D coseismic slip vectors along the 2019 Ridgecrest surface [...]