Preprints
Filtering by Subject: Physical Sciences and Mathematics
A genetic model of the magnetite-apatite deposits on El Laco volcano by extrusion of iron-rich melt
Published: 2022-08-25
Subjects: Dynamical Systems, Earth Sciences, Fluid Dynamics, Geochemistry, Geology, Numerical Analysis and Scientific Computing, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Magnetite-apatite deposits are important sources of iron and other metals. A prominent exam- ple are the magnetite lavas at the El Laco volcano, Northern Chile. Their formation processes remain debated. Here, we test the genetic hypothesis that an Fe-rich melt separated from silicate magma and ascended along collapse-related fractures. We complement recent analy- ses with thermodynamic modelling [...]
Lithology, pore-filling media, and pore closure depth beneath InSight on Mars inferred from shear wave velocities
Published: 2022-08-25
Subjects: Physical Sciences and Mathematics
We quantify the volume and distribution of water, cement, sediments, and fractured rocks within the Martian crust beneath NASA's InSight (Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport mission) lander by using rock physics models to interpret shear wave velocities Vs measured from InSight data. The models assume that Mars' crust comprises sediments and fractured [...]
Groundwater deeper than 500 m contributes less than 0.1% of global river discharge
Published: 2022-08-25
Subjects: Physical Sciences and Mathematics
Groundwater is one of the largest reservoirs of water on Earth but has relatively small fluxes compared to its volume. This behaviour is exaggerated at depths below 500 m, where the majority of groundwater exists and where residence times of millions to even a billion years have been documented. However, the extent of interactions between deep groundwater (>500 m) and the rest of the terrestrial [...]
The salmonid and the subsurface: Hillslope storage capacity determines the quality and distribution of fish habitat
Published: 2022-08-25
Subjects: Life Sciences, Physical Sciences and Mathematics
Water in rivers is delivered via the critical zone that mantles landscapes. Consequently, the success of stream-rearing salmonids depends on the structure and resulting water storage and release processes of this zone. Physical processes below the land surface (the subsurface component of the critical zone) ultimately determine how landscapes ‘filter’ climate to manifest ecologically significant [...]
Thermal forcing expected to modulate convection in a mechanically forced stationary wave
Published: 2022-08-16
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Physical Sciences and Mathematics
This is a reply to the comment by Lofverstrom and Thirumalai on our publication in Nature. That comment and this reply underwent peer review at Nature, and Nature declined to publish the exchange
Algorithm theoretical basis document for GEDI footprint aboveground biomass density
Published: 2022-08-14
Subjects: Engineering, Physical Sciences and Mathematics
The Global Ecosystem Dynamics Investigation (GEDI) lidar is a multibeam laser altimeter on the International Space Station (ISS). GEDI is the first spaceborne instrument designed to measure vegetation height and to quantify aboveground carbon stocks in temperate and tropical forests and woodlands. This document describes the algorithm theoretical basis underpinning the development of the GEDI [...]
Understanding recent tropospheric ozone trends in the context of large internal variability: A new perspective from chemistry-climate model ensembles
Published: 2022-08-12
Subjects: Physical Sciences and Mathematics
Observational records of meteorological and chemical variables are imprinted by an unknown combination of anthropogenic activity, natural forcings, and internal variability. With a 15-member initial-condition ensemble generated from the CESM2-WACCM6 chemistry-climate model for 1950-2014, we extract signals of anthropogenic (‘forced’) change from the noise of internally arising climate [...]
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 [...]