Preprints
Filtering by Subject: Geophysics and Seismology
Shear-wave attenuation anisotropy: a fluid detection tool
Published: 2023-08-23
Subjects: Geophysics and Seismology
The behaviour of fluids in preferentially aligned fractures plays an important role in a range of dynamic processes within the Earth. In the near-surface, understanding systems of fluid-filled fractures is crucial for applications such as geothermal energy production, monitoring CO2 storage sites and exploration for metalliferous sub-volcanic brines. Mantle melting is a [...]
Generation of evolving plate boundaries and toroidal flow from visco-plastic damage-rheology mantle convection and continents
Published: 2023-08-17
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure
Earth's style of planetary heat transport is characterized by plate tectonics which requires rock strength to be reduced plastically in order to break an otherwise stagnant lithospheric lid, and for rocks to have a memory of past deformation to account for strain localization and the hysteresis implied by geological sutures. Here, we explore $\sim$10$^7$ Rayleigh number, visco-plastic, [...]
Pressurizing magma within heterogeneous crust: a case study at the Socorro Magma Body, New Mexico, USA
Published: 2023-08-02
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Surface deformation plays a key role in illuminating magma transport at active volcanoes, however, unambiguous separation of deep and shallow transport remains elusive. The Socorro Magma Body (SMB) lacks an upper crustal magma transport system, allowing us to link geodetic measurements with predictions of numerical models investigating rheologic heterogeneities and magma-mush interaction in the [...]
3D shear wave velocity structure in the southwestern Okinawa Trough
Published: 2023-07-28
Subjects: Geophysics and Seismology
The southwestern Okinawa Trough is an active back-arc basin, extending and rifting within the continental lithosphere. Studying the southwestern Okinawa Trough is important for understanding the processes involved in the opening and development of a back-arc basin. At various times between 2010 and 2018, the Institute of Earth Sciences, Academia Sinica, Taiwan deployed 34 Ocean Bottom [...]
Mapping Permafrost Variability and Degradation Using Seismic Surface Waves, Electrical Resistivity, and Temperature Sensing: A Case Study in Arctic Alaska
Published: 2023-07-19
Subjects: Civil Engineering, Geophysics and Seismology, Geotechnical Engineering, Hydrology
Subsurface processes significantly influence surface dynamics in permafrost regions, necessitating utilizing diverse geophysical methods to reliably constrain permafrost characteristics. This research uses multiple geophysical techniques to explore the spatial variability of permafrost in undisturbed tundra and its degradation in disturbed tundra in Utqiaġvik, Alaska. Here, we integrate multiple [...]
Transporting Heat Flux From the US and Europe to Antarctica Guided by Regional Seismic Structure
Published: 2023-07-07
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics
Subglacial geothermal heat flux affects the dynamics of the Antarctic ice sheet but is poorly known. We estimate heat flux across West Antarctica and the interior of East Antarctica by transporting heat flux observations from the contiguous US and Europe, based on seismic structure with a lateral resolution of about \qty{100}{km}. We transport with three Machine Learning models across a hierarchy [...]
Statistical Evaluation of Seismic Velocity Models of Permafrost
Published: 2023-06-30
Subjects: Geophysics and Seismology, Geotechnical Engineering
The warming climate in high-latitude permafrost regions is leading to permafrost degradation. Estimating seismic velocity in permafrost can help predict the geomechanical properties of permafrost and provide information for planning and designing resilient civil infrastructure in cold regions. Seismic velocities of permafrost are mainly influenced by three components in permafrost: soil grains, [...]
THIN SHEET AUTOMATIC INTERPRETATION OF DIKE SWARM MAGNETIC TRANSECTS USING REGULARIZED SECOND DERIVATIVES
Published: 2023-06-30
Subjects: Geophysics and Seismology
Dike swarms are major continental structures recording large igneous provinces and crustal extension processes generating rifts and sedimentary basins. A key point in dike swarm studies is determining a minimum number of dikes that are necessary to explain the observed magnetic anomalies and inferences about position and depth for specific unities. We develop an automatic interpretation procedure [...]
Explainable Machine Learning for Hydrocarbon Prospect Risking
Published: 2023-06-20
Subjects: Geophysics and Seismology, Statistics and Probability
Hydrocarbon prospect risking integrates information from multiple geophysical data and modalities to arrive at a probability of success for a given prospect. The DHI database of drilled prospects gathers data from prospects drilled around the world in multiple geologic settings in one central knowledge base. A major goal of interest to geophysicists is to understand the impact of various seismic [...]
Adaptive Finetuning of 3D CNNs with Interpretation Uncertainty for Seismic Fault Prediction
Published: 2023-06-20
Subjects: Geophysics and Seismology, Signal Processing
3D CNNs can exploit the full extent of spatial information in seismic volumes to predict faults. They require large quantities of training data, but this issue has been mitigated by training such networks with large amounts of synthetic training data to apply afterwards on real datasets. Because of domain shift, pre-trained networks may fail to perform as expected, emphasizing the need to [...]
Applying Machine Learning to Characterize and Transport the Relationship Between Seismic Structure and Surface Heat Flux
Published: 2023-06-15
Subjects: Geophysics and Seismology, Glaciology
Geothermal heat flux beneath the Greenland and Antarctic ice sheets is an important boundary condition for ice sheet dynamics. Subglacial heat flux is rarely measured directly, so it has been inferred indirectly from proxies (e.g. seismic structure, magnetic Curie depth, surface topography). We seek to improve understanding of the relationship between heat flux and one such proxy---seismic [...]
Seismic Stratigraphy of Contourite Drift Deposits Associated with the Loop Current on the Eastern Campeche Bank, Gulf of Mexico
Published: 2023-06-08
Subjects: Geophysics and Seismology, Oceanography, Sedimentology, Stratigraphy
The Loop Current is a key component of global circulation via the northward transport of warm, salty water and an important influence on Gulf of Mexico hydrography. Understanding how the Loop Current will respond to ongoing anthropogenic warming is critically important, but the history of the Loop Current is poorly known. Here, we present the results of a high resolution (3-8 m) multichannel [...]
Automated shear-wave splitting analysis for single- and multi- layer anisotropic media
Published: 2023-06-07
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Shear-wave velocity anisotropy is present throughout the earth. The strength and orientation of anisotropy can be observed by shear-wave splitting (birefringence) accumulated between earthquake sources and receivers. Seismic deployments are getting ever larger, increasing the number of earthquakes detected and the number of source-receiver pairs. Here, we present a new software package, SWSPy, [...]
A diffuse interface method for earthquake rupture dynamics based on a phase-field model
Published: 2023-06-01
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
In traditional modeling approaches, earthquakes are often depicted as displacement discontinuities across zero-thickness surfaces embedded within a linear elastodynamic continuum. This simplification, however, overlooks the intricate nature of natural fault zones and may fail to capture key physical phenomena integral to fault processes. Here, we propose a diffuse interface description for [...]
Full vector inversion of magnetic microscopy images using Euler deconvolution as a priori information
Published: 2023-06-01
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Paleomagnetic data are usually obtained from whole cylindric samples, where the signal results from the sum of magnetic moments from hundreds of thousands to millions of magnetic particles within the sample volume. This usually includes both stable and unstable remanence carriers. Recently, magnetic microscopy techniques allowed the investigation of individual grains by directly imaging their [...]