Preprints
Filtering by Subject: Geophysics and Seismology
A Self-Supervised Deep Learning Approach for Blind Denoising and Waveform Coherence Enhancement in Distributed Acoustic Sensing Data
Published: 2021-03-03
Subjects: Artificial Intelligence and Robotics, Geophysics and Seismology
Fibre-optic Distributed Acoustic Sensing (DAS) is an emerging technology for vibration measurements with numerous applications in seismic signal analysis, including microseismicity detection, ambient noise tomography, earthquake source characterisation, and active source seismology. Using laser-pulse techniques, DAS turns (commercial) fibre-optic cables into seismic arrays with a spatial sampling [...]
Inversionson: Fully Automated Seismic Waveform Inversions
Published: 2021-03-03
Subjects: Geophysics and Seismology, Numerical Analysis and Scientific Computing, Software Engineering
We present Inversionson, a Python package that fully automates modern full-waveform inversions (FWI). It supports traditional FWI, which uses the same set of events and a single simulation mesh in each iteration, as well as more advanced workflows that exploit the use of dynamic mini-batches and wavefield-adapted meshes. These recently introduced advancements can be time-consuming and [...]
Gradient-boosted equivalent sources
Published: 2021-02-25
Subjects: Earth Sciences, Geophysics and Seismology
The equivalent source technique is a powerful and widely used method for processing gravity and magnetic data. Nevertheless, its major drawback is the large computational cost in terms of processing time and computer memory. We present two techniques for reducing the computational cost of equivalent source processing: block-averaging source locations and the gradient-boosted equivalent source [...]
Episodicity and Migration of Low Frequency Earthquakes modeled with Fast Fluid Pressure Transients in the Permeable Subduction Interface
Published: 2021-02-24
Subjects: Geophysics and Seismology
In many subduction zones, the plate interface hosts intermittent, low-frequency, low-magnitude seismic tremor and low-frequency earthquakes (LFEs). Seismic activity clusters in episodic bursts that migrate along the fault zone in complex ways. Geological structures in fossil tremor source regions testify to large and pervasive variations of fluid pressure and permeability. Here, we explore the [...]
The surface deformation of the 2020 Doğanyol-Sivrice earthquake (Mw 6.8) and the earlier events suggest Mw˂7.0 earthquakes do not create significant surface slip along the East Anatolian Fault Zone
Published: 2021-02-18
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure
The 2020 Mw 6.8 Doğanyol-Sivrice earthquake occurred on the Pütürge Segment of the left-lateral East Anatolian Fault Zone (EAFZ). Our field investigation within 6 weeks after the earthquake suggests the following results. (1) The 2020 earthquake created a ~54-km-long surface deformation zone along the Pütürge Segment. (2) No co-seismic surface slip has been formed after the earthquake. (3) The [...]
Co- and postseismic slip behaviors extracted from decadal seafloor geodesy after the 2011 Tohoku-oki earthquake
Published: 2021-02-16
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics
Investigations of the co- and postseismic processes of the 2011 Tohoku-oki earthquake provide essential information on the seismic cycle in the Japan Trench. Although various postseismic models have been proposed, no consensus has been reached, especially on the along-strike extensions of the main rupture due to the lack of conclusive evidence, even in the coseismic process. To decompose the [...]
Audible acoustics from low-magnitude fluid-induced earthquakes in Finland
Published: 2021-02-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquakes are frequently accompanied by public reports of audible low-frequency noises. In 2018, public reports of booms or thunder-like noises were linked to induced earthquakes during a Engineered Geothermal System project in the Helsinki Metropolitan area. In response, two microphone arrays were deployed to record and study these acoustic signals while stimulation at the drill site [...]
Upper Mantle Radial Anisotropy Under the Indian Ocean from Higher Mode Surface Waves and a Hierarchical Transdismensional Approach
Published: 2021-02-03
Subjects: Earth Sciences, Geophysics and Seismology
We investigated the likelihood of radial anisotropy in the shallow and deep upper mantle, including the mantle transition zone (MTZ) under the Indian Ocean. Seismic anisotropy can be an indicator of mantle deformation through lattice preferred orientation of anisotropic crystals in the mantle. It has thus the potential to illuminate Earth's dynamic interior, but previous seismic tomography [...]
Ordination analysis in sedimentology, geochemistry and paleoenvironment - background, current trends and recommendations
Published: 2021-02-01
Subjects: Biogeochemistry, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Multivariate Analysis, Oil, Gas, and Energy, Other Earth Sciences, Paleobiology, Paleontology, Sedimentology
Ordination is the name given to a group of methods used to analyze multiple variables without preceding hypotheses. Over the last few decades the use of these methods in Earth science in general, and notably in analyses of sedimentary sources, has dramatically increased. However, with limited resources oriented towards Earth scientists on the topic, the application of ordination analysis is at [...]
Back-propagating rupture evolution within a curved slab during the 2019 Mw 8.0 Peru intraslab earthquake
Published: 2021-01-28
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The 26 May 2019 Mw 8.0 Peru intraslab earthquake ruptured the subducting Nazca plate where the dip angle of the slab increases sharply and the strike angle rotates clockwise from the epicentre to north. To obtain a detailed seismic source model of the 2019 Peru earthquake, including not only the rupture evolution but also the spatiotemporal distribution of focal mechanisms, we performed [...]
Learning in a Crisis: Online Skill Building Workshop Addresses Immediate Pandemic Needs and Offers Possibilities for Future Trainings
Published: 2021-01-28
Subjects: Computer Sciences, Earth Sciences, Education, Geophysics and Seismology, Scholarship of Teaching and Learning
The COVID-19 pandemic led to the suspension of many summer research opportunities for STEM students. In response, the IRIS Education and Outreach program, in collaboration with Miami University, offered a free online Seismology Skill Building Workshop to increase undergraduates' knowledge, skills, self-efficacy, and interest in observational seismology and scientific computing. Registrations were [...]
101 Geodynamic modelling: How to design, interpret, and communicate numerical studies of the solid Earth
Published: 2021-01-27
Subjects: Geophysics and Seismology
Geodynamic modelling provides a powerful tool to investigate processes in the Earth's crust, mantle, and core that are not directly observable. However, numerical models are inherently subject to the assumptions and simplifications on which they are based. In order to use and review numerical modelling studies appropriately, one needs to be aware of the limitations of geodynamic modelling as well [...]
Observational estimates of dynamic topography through space and time
Published: 2021-01-24
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Paleobiology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure, Volcanology
Earth's mantle undergoes convection on million-year timescales as heat is transferred from depth to the surface. Whilst this flow has long been linked to the large-scale horizontal forces that drive plate tectonics and supercontinent cycles, geologists are increasingly recognising the signature of convection through transient vertical motions in the rock record, known as "dynamic topography". A [...]
Earthquake rupture on multiple splay faults and its effect on tsunamis
Published: 2021-01-16
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Detailed imaging of accretionary wedges reveals splay fault networks that could pose a significant tsunami hazard. However, the dynamics of multiple splay fault activation during megathrust earthquakes and the consequent effects on tsunami generation are not well understood. We use a 2-D dynamic rupture model with complex topo-bathymetry and six curved splay fault geometries constrained from [...]
Integrated magnetotelluric and petrological analysis of felsic magma reservoirs: Insights from Ethiopian rift volcanoes
Published: 2021-01-16
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Volcanology
Geophysical and petrological probes are key to understanding the structure and the thermochemical state of active magmatic systems. Recent advances in laboratory analyses, field investigations and numerical methods have allowed increasingly complex data-constraint models with new insights into magma plumbing systems and melt evolution. However, there is still a need for methods to quantitatively [...]