Preprints
Filtering by Subject: Geophysics and Seismology
Evidence that seismic anisotropy captures upstream palaeo ice fabric: Implications on present day deformation at Whillans Ice Stream, Antarctica
Published: 2023-11-16
Subjects: Earth Sciences, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics
Understanding deformation and slip at ice streams, which are responsible for 90% of Antarctic ice loss, is vital for accurately modelling large-scale ice flow. Ice preferred crystal orientation fabric (COF) has a first-order effect on ice stream deformation. For the first time, we use shear-wave splitting (SWS) measurements of basal icequakes at Whillans Ice Stream (WIS), Antarctica, to determine [...]
Quantifying mantle mixing through configurational Entropy
Published: 2023-11-09
Subjects: Geophysics and Seismology, Other Earth Sciences
Geodynamic models of mantle convection provide a powerful tool to obtain insights into the structure and composition of the Earth’s mantle that resulted from a long history of differentiating and mixing. Comparing such models with geophysical and geochemical observations is challenging as these datasets often sample entirely different temporal and spatial scales. Here, we explore the use of [...]
Deep Learning for Deep Earthquakes: Insights from OBS Observations of the Tonga Subduction Zone
Published: 2023-11-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Applications of machine learning in seismology have greatly improved our capability of detecting earthquakes in large seismic data archives. Most of these efforts have been focused on continental shallow earthquakes, but here we introduce an integrated deep-learning-based workflow to detect deep earthquakes recorded by a temporary array of ocean-bottom seismographs (OBSs) and land-based stations [...]
Pygoda: a graphical interface to efficiently visualise and explore large sets of geolocated time series
Published: 2023-10-24
Subjects: Categorical Data Analysis, Climate, Computer Sciences, Databases and Information Systems, Earth Sciences, Environmental Monitoring, Environmental Sciences, Environmental Studies, Fresh Water Studies, Geographic Information Sciences, Geophysics and Seismology, Glaciology, Graphics and Human Computer Interfaces, Hydrology, Longitudinal Data Analysis and Time Series, Meteorology, Other Earth Sciences, Other Statistics and Probability, Spatial Science
Modern-day data sets in geosciences may comprise hundreds or thousands of geolocated time series. Despite all the automated tools and new algorithms now available to process and prepare those data before using them in research projects, it can be useful or even necessary to visualise and investigate them manually. Whether it be for data quality assessment, for the preparation of a training data [...]
The importance of anisotropic viscosity in numerical models for olivine textures in shear and subduction deformations
Published: 2023-10-05
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Olivine lattice preferred orientation (LPO), or texture, forms in relation to deformation mechanisms such as dislocation creep and can be observed in the upper mantle as seismic anisotropy. Olivine is also mechanically anisotropic, meaning that it responds to stresses differently depending on the direction of the stress. Understanding the interplay between anisotropic viscosity (AV) and LPO, and [...]
Antarctic Geothermal Heat Flow, Crustal Conductivity and Heat Production Inferred From Seismological Data
Published: 2023-09-15
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Geothermal heat flow is a key parameter in governing ice dynamics, via its influence on basal melt and sliding, englacial rheology, and erosion. It is expected to exhibit significant lateral variability across Antarctica. Despite this, surface heat flow derived from Earth's interior remains one of the most poorly constrained parameters controlling ice-sheet evolution. To obtain a continent-wide [...]
A Cascadia Slab Model from Receiver Functions
Published: 2023-09-08
Subjects: Earth Sciences, Geophysics and Seismology
We map the characteristic signature of the subducting Juan de Fuca and Gorda plates along the entire Cascadia forearc from northern Vancouver Island, Canada to Cape Mendocino in northern California, USA, using teleseismic receiver functions. The subducting oceanic crustal complex, possibly including subcreted material, is parameterized by three horizons capable of generating mode-converted waves: [...]
Imaging evidence of subduction, collision, and extension in northern Borneo: Constraints from receiver function
Published: 2023-09-04
Subjects: Earth Sciences, Geophysics and Seismology
Northern Borneo (Sabah) has a complex geological history, having experienced multiple episodes of subduction, magmatism, uplift, subsidence, and extension since the Mesozoic. This includes the subduction of the proto-South China Sea beneath what is now the north-western margin of Sabah, which terminated ~21 Ma; a postulated later phase of northward subduction of the Celebes Sea plate, which [...]
High Accuracy Estimation and Validation of InSAR-derived Surface Displacements at Temperate Raised Peatlands
Published: 2023-09-04
Subjects: Geophysics and Seismology, Hydrology, Soil Science
Peatland surface motion derived from satellite-based Interferometry of Synthetic Aperture Radar (InSAR) is potentially a proxy for groundwater level variations and greenhouse gas emissions from peat soils. Ground validation of these motions at equivalent temporal resolution and accuracy has proven problematic because of limitations of traditional surveying methods. Since 2019, peat surface motion [...]
The Role of Continental Heterogeneity on the Evolution of Continental Margin Topography at Subduction Zones
Published: 2023-09-01
Subjects: Earth Sciences, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The nature of the overriding plate plays a major role in shaping subduction zone processes. In particular, the highly heterogeneous continental lithosphere modulates intra-plate tectonics and the surface evolution of our planet. However, the role of continental heterogeneity is relatively under-explored for the dynamics of subduction models. We investigate the influence of rheological and density [...]
SeisMIC - an Open Source Python Toolset to Compute Velocity Changes from Ambient Seismic Noise
Published: 2023-09-01
Subjects: Computer Sciences, Earth Sciences, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We present SeisMIC, a fast, versatile, and adaptable open-source software to estimate seismic velocity changes from ambient seismic noise. SeisMIC includes a broad set of tools and functions to facilitate end-to-end processing of ambient noise data, from data retrieval and raw data analysis via spectrogram computation, over waveform coherence analysis, to post-processing of the final velocity [...]
Knowledge Graphs for Seismic Data and Metadata
Published: 2023-08-31
Subjects: Databases and Information Systems, Geophysics and Seismology
The increasing scale and diversity of seismic data, and the growing role of big data in seismology, has raised interest in methods to make data exploration more accessible. This paper presents the use of knowledge graphs (KGs) for representing seismic data and metadata to improve data exploration and analysis, focusing on usability, flexibility, and extensibility. Using constraints derived from [...]
Forecast of Earthquake Magnitude for North-West (NW) Indian Region Using Machine Learning Techniques
Published: 2023-08-24
Subjects: Geophysics and Seismology
Earthquakes have posed significant hazards to human lives and infrastructure for as far back as can be recalled. This paper presents a Machine Learning (ML) based approach for earthquake magnitude forecasting spatially using the earthquake clustering in five selected zones of NW Indian region. Previous research efforts have primarily relied on empirical relationships and statistical models, which [...]
Shear-wave attenuation anisotropy: a fluid detection tool
Published: 2023-08-24
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, [...]