Preprints
Filtering by Subject: Physical Sciences and Mathematics
Validating mechanistic models of fluid displacement during imbibition
Published: 2022-08-11
Subjects: Physical Sciences and Mathematics
Pore-scale modelling is an important tool to improve our understanding of multiphase flow in porous media. Slow fluid invasion is commonly modelled using quasi-static pore network models (PNM). These models simulate the invasion in a network of simplified pores and throats by invading network elements in order of the quasi-static “invasion” capillary pressure needed for the invading fluid to [...]
A note on climate science and climate policy
Published: 2022-08-10
Subjects: Physical Sciences and Mathematics
A short note on climate science and climate policy, discussing planning vs acting, and the differences between decision making and regret under uncertainty and in a deterministic environment.
SubZero: A Sea Ice Model with an Explicit Representation of the Floe Life Cycle
Published: 2022-08-08
Subjects: Physical Sciences and Mathematics
Sea ice dynamics exhibit granular behavior as individual floes and fracture networks become particularly evident at length scales O(10--100) km and smaller. However, climate models do not resolve floes and represent sea ice as a continuum, while existing floe-scale sea ice models tend to oversimplify floes using discrete elements of predefined simple shapes. The idealized nature of climate and [...]
Estimating the Occurrence of Slow Slip Events and Earthquakes with an Ensemble Kalman Filter
Published: 2022-08-07
Subjects: Applied Mathematics, Earth Sciences, Physical Sciences and Mathematics
Our ability to forecast earthquakes and slow slip events is hampered by limited information on the current state of stress on faults. Ensemble data assimilation methods permit estimating the state by combining physics-based models and observations, while considering their uncertainties. We employ an Ensemble Kalman Filter (EnKF) to estimate shear stresses, slip rates, and the state theta acting [...]
A High-order Accurate Summation-by-Parts Finite Difference Method for Fully-dynamic Earthquake Sequence Simulations within Sedimentary Basins
Published: 2022-08-06
Subjects: Applied Mathematics, Earth Sciences, Physical Sciences and Mathematics
We present a computationally efficient numerical method for earthquake sequences that incorporates wave propagation during rupture. A vertical strike-slip fault governed by rate-and-state friction is embedded in a heterogeneous elastic half-space discretized using a high-order accurate Summation-by-Parts finite difference method. We develop a two solver approach: Adaptive time-stepping is [...]
Within the subducting Nazca Plate: The 2020 Mw 6.8 Calama earthquake and its similarity with the surrounding inslab seismicity
Published: 2022-08-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We study the 2020 MW 6.8 Calama earthquake sequence that occurred within the subducting oceanic Nazca plate. The mainshock is modeled via waveform inversion using a dynamic rupture model, while detection and location techniques are used to better characterize its aftershock sequence. We analyze the local seismotectonic and thermal context of the subducting Nazca plate to understand the trigger [...]
Influence of reef isostasy, dynamic topography, and glacial isostatic adjustment on sea-level records in Northeastern Australia
Published: 2022-08-04
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Understanding sea level during the warmest peak of the Last Interglacial (125,000 yrs ago; Marine Isotope Stage 5e) is important for assessing future ice-sheet dynamics in response to climate change, and relies on the measurement and interpretation of paleo sea-level indicators, corrected for post-depositional vertical land motions. The coasts and continental shelves of northeastern Australia [...]
MinPlot: A mineral formula recalculation and plotting program for electron probe microanalysis
Published: 2022-08-03
Subjects: Physical Sciences and Mathematics
MinPlot is a MATLAB®-based mineral formula recalculation and compositional plotting program for electron microprobe analyses (EPMA). The program offers recalculation and structural formula assignment for 15 different mineral groups: Garnet, pyroxene, olivine, amphibole, feldspar, mica, staurolite, cordierite, chlorite, chloritoid, talc, epidote, titanite, spinel, and sulfides. MinPlot is a fast [...]
Geochemical implication of Eu isotopic ratio in anorthosite: new evidence of Eu isotope fractionation during feldspar crystallization
Published: 2022-07-25
Subjects: Earth Sciences, Physical Sciences and Mathematics
Rare earth element geochemistry can provide critical information on the evolution of the crust-mantle system. Europium (Eu) exists in divalent and trivalent states, and Eu2+ can substitute for Ca2+ during plagioclase feldspar crystallization in reducing magmas. This leads to positive Eu anomaly in Ca-plagioclase-rich anorthosite derived from the mantle and negative Eu anomalies in fractionated [...]
Machine Learning for Elastic-Electrical Cross-Property Modelling Of Sandstones
Published: 2022-07-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Middle Miocene (Serravallian) wetland development on the northwest edge of Europe based on palynological analysis of the uppermost Brassington Formation of Derbyshire, United Kingdom
Published: 2022-07-23
Subjects: Life Sciences, Physical Sciences and Mathematics
The Middle Miocene was a warmer and wetter interval than present-day (Steinthorsdottir et al., 2021). In the UK, the most extensive Middle Miocene deposit is the Serravallian Kenslow Member of the Brassington Formation as exposed at Bees Nest Pit, near Brassington, Derbyshire, UK. While known to contain a diverse palynological and palaeobotanical record, the stratigraphical distribution of these [...]
Analytical and numerical modeling of viscous anisotropy: A toolset to constrain the role of mechanical anisotropy for regional tectonics and fault loading
Published: 2022-07-12
Subjects: Education, Engineering, Physical Sciences and Mathematics
Whether mechanical anisotropy is required to explain the dynamics of the lithosphere, in particular near fault zones where it may affect loading stresses, is an important yet open question. If anisotropy affects deformation, how can we quantify its role from observations? Here, we derive analytical solutions and build a theoretical framework to explore how a shear zone with anisotropic viscosity [...]
High-Precision Triple Oxygen Isotope Analysis of Carbon Dioxide by Tunable Infrared Laser Absorption Spectroscopy
Published: 2022-07-12
Subjects: Physical Sciences and Mathematics
Precision measurements of the stable isotope ratios of oxygen (18O/16O, 17O/16O) in CO2 are critical to atmospheric monitoring and terrestrial climate research. High-precision 17O measurements by isotope ratio mass spectrometry (IRMS) are challenging because they require complicated sample preparation procedures, long measurement times, and relatively large samples sizes. Recently, tunable [...]
I = P AT equation: the weight of the P factor in addressing climate change
Published: 2022-07-09
Subjects: Physical Sciences and Mathematics
A dominant narrative is that addressing population is not relevant to mitigating climate change because population is only growing in the poorest countries, whose contribution to global emissions is negligible. An analysis of carbon emissions and population for the World Bank’s four income-based country groups, however, shows that: (i) the low-income group represents the smallest fraction of the [...]
Thermobar: An Open-Source Python3 Tool for Thermobarometry and Hygrometry
Published: 2022-07-09
Subjects: Physical Sciences and Mathematics
We present Thermobar, a new open-source Python3 package for calculating pressures, temperatures, and melt compositions from mineral and mineral-melt equilibrium. Thermobar allows users to perform calculations with >100 popular parametrizations involving liquid, olivine-liquid, olivine-spinel, pyroxene only, pyroxene-liquid, two pyroxene, feldspar-liquid, two feldspar, amphibole only, [...]