Preprints
Filtering by Subject: Physical Sciences and Mathematics
Simultaneous deformation along the Main Ethiopian Rift and associated transversal lineaments: an analogue modelling perspective
Published: 2024-08-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The interaction between the NE-SW striking Main Ethiopian Rift (MER) and the E-W oriented Yerrer-Tullu Wellel Volcano-tectonic lineament (YTVL) represents one of the least understood tectonic problems in the East African Rift System. Despite the numerous studies that have been conducted in the region, the following questions still remain to be answered: did the MER and YTVL evolve simultaneously? [...]
Physical Mechanisms of Earthquake Nucleation and Foreshocks: Cascade Triggering, Aseismic Slip, or Fluid Flows?
Published: 2024-08-30
Subjects: Physical Sciences and Mathematics
Earthquakes are caused by the rapid rupture of their seismogenic faults. Whether large or small, there is inevitably a certain nucleation process involved before the dynamic rupture. At the same time, although not very common, significant foreshock activity has been observed before some large earthquakes. Understanding the nucleation process and foreshocks of earthquakes, especially large [...]
Towards a widely applicable earthquake detection algorithm for fibreoptic and hybrid fibreoptic-seismometer networks
Published: 2024-08-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Distributed Acoustic Sensing (DAS) is a promising technology for providing dense (metre-scale) sampling of the seismic wavefield. However, harnessing this potential for earthquake detection with accurate phase picking and associated localisation remains challenging. Single-channel algorithms are limited by individual channel noise, while machine learning and semblance methods are typically [...]
Two-dimensional Ekman-Inertial Instability: A comparison with Inertial Instability
Published: 2024-08-29
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In the ocean, submesoscale flows tend to undergo several hydrodynamic instabilities. In particular, Inertial Instability (InI) and Ekman-Inertial Instability (EII) are known to develop in geostrophically balanced barotropic flows whose lateral shear is larger in magnitude and opposite in sign to the Coriolis parameter. Although these instabilities share some elements, their dynamical nature can [...]
Two-layer formulation for long-runout turbidity currents: theory and bypass flow case
Published: 2024-08-29
Subjects: Engineering, Physical Sciences and Mathematics
Turbidity currents, which are stratified, sediment-laden bottom flows in the ocean or lakes, can run out for 100's to 1000's of kilometers in submarine channels without losing their stratified structure. Here we derive a layer-averaged, two-layer model for turbidity currents, specifically designed to capture long-runout. Previous models have captured runout only 10’s of kilometers, beyond which [...]
Rupture Dynamics and Near-Fault Ground Motion of the Mw7.8 Kahramanmaraş, Turkey earthquake of February 6, 2023
Published: 2024-08-28
Subjects: Physical Sciences and Mathematics
We studied the dynamic rupture propagation of the February 6th, 2023 (Mw7.8, 01:17 UTC) Pazarcık (Kahramanmaraş), Turkey, earthquake by incorporating the non-planar fault structure, the regional stress field, and a data-driven friction parameterization into numerical simulations. To explain the rupture extent of 200 km and the average speed, a regional non-uniform load is necessary and was [...]
Localized west-dipping seismic structure defines the Elgin-Lugoff Swarm Sequence in South Carolina
Published: 2024-08-28
Subjects: Education, Physical Sciences and Mathematics
An unusual earthquake swarm began in December 2021 between the towns of Elgin and Lugoff in South Carolina, United States. This area is characterized by historically low seismicity, but by April 2024 it has experienced 97 small earthquakes listed in the United States Geological Survey (USGS) catalog, presenting a unique opportunity to investigate the dynamics of earthquake swarms in stable [...]
Distinct roles for precession, obliquity and eccentricity in Pleistocene 100kyr glacial cycles
Published: 2024-08-27
Subjects: Physical Sciences and Mathematics
Identifying the specific roles of precession, obliquity and eccentricity in glacial/interglacial transitions is hindered by imprecise age control. We circumvent this problem by focussing on the morphology of deglaciation/inception, which we show depends strongly on the relative phasing of precession versus obliquity. We demonstrate that while both parameters are important, precession has more [...]
Array-based seismic measurements of OSIRIS-REx's re-entry
Published: 2024-08-23
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Sciences
The return home of the OSIRIS-REx spacecraft in September 2023 marked only the fifth time that an artificial object entered the Earth's atmosphere at interplanetary velocities. Although rare, such events serve as valuable analogues for natural meteoroid re-entries; enabling study of hypersonic dynamics, shockwave generation, and acoustic-to-seismic coupling. Here, we report on the signatures [...]
Complex and confined laboratory ruptures explain scaling of the critical slip distance for earthquake faulting
Published: 2024-08-22
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Earthquake sequences in nature are complex, exhibiting a range of magnitudes and slip behaviors. In contrast, earthquake-like instabilities generated on frictional faults in the laboratory and in continuum numerical models are usually quasi-periodic with a smaller range of magnitudes and durations. The discrepancy, especially apparent for cm-sized samples used in lab friction experiments, has [...]
Larger and Steadier Warming since 1850 from Harmonized Land and Ocean Temperature Records
Published: 2024-08-22
Subjects: Physical Sciences and Mathematics
Accurate historical temperature estimates are crucial for understanding current warming levels and informing policy decisions. Trends in global land and ocean temperatures diverge, however, before 1945. Inter-calibration of coastal land-ocean temperatures indicates that this divergence arises from under-corrected biases in sea-surface temperature linked to late 19th century instrumentation [...]
The Effect of Rayleigh-Love Coupling in an Anisotropic Medium
Published: 2024-08-17
Subjects: Physical Sciences and Mathematics
For a weakly anisotropic medium, Rayleigh and Love wave phase speeds at angular frequency $\omega$ and propagation azimuth $\psi$ are given approximately by $V(\omega,\psi) = A_0 + A_{2c} \cos 2 \psi + A_{2s} \sin 2 \psi + A_{4c} \cos 4 \psi + A_{4s} \sin 4 \psi$. Earlier theories of the propagation of surface waves in anisotropic media based on non-degenerate perturbation theory predict that the [...]
Spatial Variability of Water Temperature within the White River Basin, Mount Rainier National Park, Washington
Published: 2024-08-16
Subjects: Life Sciences, Physical Sciences and Mathematics
Water temperature is a primary control on the occurrence and distribution of cold-water species. Rivers draining Mount Rainier in western Washington, including the White River along its northern flank, support several cold-water fish populations, but the spatial distribution of water temperatures, particularly during late-summer base flow between August and September, and the climatic, [...]
The influence of wildfire smoke on ambient chemical species concentrations in the contiguous US
Published: 2024-08-14
Subjects: Environmental Sciences, Physical Sciences and Mathematics
Wildfires are a significant contributor to ambient air pollution and pose a growing public health threat in many parts of the world. Increased wildfire activity over the past few decades has exacerbated smoke exposure across the US, yet our understanding of how wildfire influences specific chemicals and their resulting concentration in smoke remains incomplete. We combine 15 years of daily [...]
A methodologically robust densification function for snow on multiyear Arctic sea ice
Published: 2024-08-13
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics