Preprints
Filtering by Subject: Geophysics and Seismology
Transient aseismic vertical deformation across the Pisia-Skinos normal fault (Gulf of Corinth, Greece)
Published: 2024-01-18
Subjects: Earth Sciences, Geophysics and Seismology, Tectonics and Structure
Geodetically-derived deformation rates are sometimes used to infer seismic hazard, implicitly assuming that short-term (annual-decadal) deformation is representative of longer-term deformation. This is despite geological observations indicating that deformation/slip rates are variable over a range of timescales. Using geodetic data from 2016-2021, we observe an up to 7-fold increase in vertical [...]
The Effects of Characteristic Slip Distance on Earthquake Nucleation Styles in Fully Dynamic Seismic Cycle Simulations
Published: 2024-01-17
Subjects: Earth Sciences, Geophysics and Seismology
Earthquake nucleation is a crucial preparation process of the following coseismic rupture propagation. Under the framework of rate-and-state friction (RSF), it was found that the ratios of a to b parameters control whether earthquakes nucleate as an expanding crack or a fixed length. However, the characteristic slip distance DRS controls the weakening efficiency of fault strength and can [...]
Dynamic evolution of competing same-dip double subduction: New perspectives of the Neo-Tethyan plate tectonics
Published: 2024-01-15
Subjects: Earth Sciences, Geophysics and Seismology, Tectonics and Structure
Same-dip double-subduction (SDDS) systems are widely reported from present as well as past complex convergent plate tectonic configurations. However, the dynamics of their evolution is poorly understood, which is crucial to conceptualize anomalous subducting slab kinematics and associated observed geological phenomena, such as irregular trench migration rates, high convergence velocities, and [...]
The Stability of Frictional Sliding on Dip-Slip and Finite-Length Faults
Published: 2024-01-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Sensitivity Analysis of Global Kinematics on Mantle Structure Using Automatically Generated Adjoint Thermochemical Convection Codes
Published: 2023-12-11
Subjects: Earth Sciences, Geophysics and Seismology, Numerical Analysis and Scientific Computing, Tectonics and Structure
Within the past 30 years, numerical models of mantle convection have been able to predict observations on Earth and planets, and among them tectonics. The possibility of building inverse problems in global geodynamics became concrete, and often involve the development of adjoint codes. Such tools provide efficient ways to estimate sensitivities of misfit functions relative to control parameters, [...]
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 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 a [...]
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: [...]
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, experiencing multiple episodes of subduction, magmatism, uplift, subsidence, and extension since the Mesozoic. This includes the subduction of the proto-South China Sea beneath Sabah, terminating ~21 Ma; a postulated later phase of subduction of the Celebes Sea plate, terminating ~9 Ma; extension in central Sabah ~9-10Ma; rapid emplacement [...]
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 [...]