Preprints
Filtering by Subject: Geophysics and Seismology
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 [...]
Seismicity modulation due to hydrological loading in a stable continental region: a case study from the Jektvik swarm sequence in Northern Norway
Published: 2022-10-10
Subjects: Geophysics and Seismology
Seismic swarms have been observed for more than 40 years along the coast of Nordland, Northern Norway. However, the detailed spatio-temporal evolution and mechanisms of these swarms have not yet been resolved due to the historically sparse seismic station coverage. An increased number of seismic stations now allows us to study a nearly decade-long swarm sequence in the Jektvik area during the [...]
Investigating the Eastern Alpine–Dinaric transition with teleseismic receiver functions: Evidence for subducted European Crust
Published: 2022-10-08
Subjects: Geophysics and Seismology, Tectonics and Structure
Distributed Acoustic Sensing in a Greenlandic Outlet Glacier: Developing Machine Learning Approaches to Benefit Cryoseismic Data Analysis
Published: 2022-10-08
Subjects: Geophysics and Seismology, Glaciology, Other Computer Sciences
The recognition of Distributed Acoustic Sensing (DAS) as a valuable tool for glaciological seismic applications is growing. However, besides the logistical challenges of installing fibre-optic cable, the volume of DAS data that can be collected in a field campaign poses computational challenges. In this paper, we show the potential of active-source DAS to image and characterise subglacial [...]
Bayesian inference on the initiation phase of the 2014 Iquique, Chile, earthquake
Published: 2022-10-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We investigate the initiation phase of the 2014 Mw8.1 Iquique earthquake in northern Chile. In particular, we focus on the month preceding the mainshock, a time period known to exhibit an intensification of the seismic and aseismic activity in the region. The goal is to estimate the time-evolution and partitioning of seismic and aseismic slip during the preparatory phase of the mainshock. To do [...]
Tsunami Early Warning from Global Navigation Satellite System Data using Convolutional Neural Networks
Published: 2022-09-29
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Oceanography
We investigate the potential of using Global Navigation Satellite System (GNSS) observations to directly forecast full tsunami waveforms in real time. We train convolutional neural networks (CNNs) to use less than 9 minutes of GNSS data to forecast the full tsunami waveforms over 6 hours at select locations, and obtain accurate forecasts on a test dataset. Our training and test data consists of [...]
python-ags4: A Python library to read, write, and validate AGS4 geodata files
Published: 2022-09-21
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geochemistry, Geology, Geophysics and Seismology, Geotechnical Engineering
Data gathered from geotechnical, geoenvironmental, and geophysical investigations can be broadly described as "geodata". The AGS4 data format is one of the most widely used data transmittal formats for geodata and is used across the world. It is a plain text format consisting of multiple tables of comma-separated values, tied together with a robust data schema and a comprehensive suite of [...]
Source location and wavefield characterization of river-induced seismic tremor
Published: 2022-09-06
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
River-induced seismic signal (tremor) recorded by deploying seismic stations close to the river can be used to obtain the flow characteristics of rivers indirectly. This task becomes challenging when the tremor is contaminated by strong cultural noise. We conducted an experiment next to Avoca River, County Wicklow, Ireland. We locate and characterize the river-induced tremor by combining the [...]
Locating Flowing Conduits in Karst Using Amplitude-based Passive Seismic Location Method
Published: 2022-09-06
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The aim of this study is to develop methods for directly detecting energetic groundwater flow in sub-surface conduits through passive seismic applications, by detecting the small ground vibrations (seismic microtremor) that flowing water in the sub-surface may generate. This is in contrast to the current ‘traditional’ approach of attempting to actively image the conduits using geophysical and [...]
Sensitivity, Accuracy and Limits of the Lightweight Three-Component SmartSolo Geophone Sensor (5 Hz) for Seismological Applications
Published: 2022-09-03
Subjects: Geophysics and Seismology
The use of Nodal systems based on autonomous geophone-based instruments entered the field of Seismology only recently. These lightweight solutions revolutionized seismological fieldwork through lightweight and wholistic instruments that are faster to deploy and easier to handle. The IGU-16HR series of SmartSolo® is one example, but yet lacking a thorough lab-based performance analysis. Here, we [...]
Rapid fault healing after seismic slip
Published: 2022-09-01
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Tectonics and Structure
Fault strength recovery (healing) following an earthquake is a key process in controlling the recurrence of future events; however, the rates and mechanisms of fault healing are poorly constrained. Here, by performing high-velocity friction experiments at seismic slip rates (0.57 m/s), we show that granite and gabbro fault gouges recover their strength rapidly after experiencing dynamic [...]