Preprints
Filtering by Subject: Physical Sciences and Mathematics
Detection and forecasting of shallow landslides: lessons from a natural laboratory
Published: 2020-11-23
Subjects: Physical Sciences and Mathematics
Rapid shallow landslides are a significant hillslope erosion mechanism and limited understanding of their initiation and development results in persistent risk to infrastructure. Here, we analyse the slope above the strategic A83 Rest and be Thankful road in the west of Scotland. An inventory of 70 landslides (2003–2020) shows three types of shallow landslide, debris flows, creep deformation, and [...]
The development of intermittent multiphase fluid flow pathways through a porous rock
Published: 2020-11-18
Subjects: Engineering, Physical Sciences and Mathematics
Intermittent fluid flow has recently been identified as an important transport mode for subsurface multiphase flow systems such as CO2 storage and natural gas production. However, due to experimental limitations, it has not been possible to identify why intermittency occurs at subsurface conditions and what the implications are for upscaled flow properties such as relative permeability. We [...]
How fast can minibasins translate down a slope? Observations from 2D numerical models
Published: 2020-11-18
Subjects: Earth Sciences, Physical Sciences and Mathematics
Minibasins are important features in salt-bearing basins and they are mostly found in salt-detached continental slopes where the sedimentary cover undergoes seaward translation. One question which is relevant to understand the structural evolution of salt-detached slopes is how fast can the sedimentary cover and the minibasins translate. The aim of this study is three-fold: 1) to compare [...]
Radiative feedbacks on land surface change and associated tropical precipitation shifts
Published: 2020-11-17
Subjects: Physical Sciences and Mathematics
Changes in land surface albedo and land surface evaporation modulate the atmospheric energy budget by changing temperatures, water vapor, clouds, snow and ice cover, and the partitioning of surface energy fluxes. Here idealized perturbations to land surface properties are imposed in a global model to understand how such forcings drive shifts in zonal mean atmospheric energy transport and zonal [...]
Boron isotopic signatures of melt inclusions from North Iceland reveal recycled material in the Icelandic mantle source
Published: 2020-11-13
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Volcanology
Trace element and volatile heterogeneity in the Earth's mantle is in uenced by the recycling of oceanic lithosphere through subduction. Oceanic island basalts commonly have high concentrations of volatiles compared to mid-ocean ridge basalts, but the extent to which this enrichment is linked to recycled mantle domains remains unclear. Boron is an ideal tracer of recycled subducted material, [...]
Backstresses from dislocation interactions quantified by nanoindentation load-drop experiments
Published: 2020-11-13
Subjects: Physical Sciences and Mathematics
Recent work has identified the importance of strain hardening and backstresses among dislocations in the deformation of geologic materials at both high and low temperatures, but very few experimental measurements of such backstresses exist. Using a nanoindentation load-drop method and a self-similar Berkovich tip, we measure backstresses in single crystals of olivine, quartz, and plagioclase [...]
The Influence of Dust Levels on Atmospheric Carbon Dioxide and Global Temperature
Published: 2020-11-13
Subjects: Physical Sciences and Mathematics
The purpose of this paper is to examine the causality between DUST, CO2 and temperature for the Vostok ice core data series [Vostok Data Series], dating from 420 000 years ago, and the EPICA C Dome data going back 800 000 years. In addition, the time-varying volatility and coefficient of variation in the CO2, dust and temperature is examined, as well as their dynamic correlations and [...]
Microseismicity appears to outline highly coupled regions on the Central Chile megathrust
Published: 2020-11-12
Subjects: Physical Sciences and Mathematics
We compiled a novel microseismicity catalog for the Central Chile megathrust (29-35◦S), comprising 8750 earthquakes between 04/2014 and 12/2018. These events describe a pattern of three trenchward open half-ellipses, consisting of a continuous, coast-parallel seismicity band at 30-45 km depth, and narrow elongated seismicity clusters that protrude to the shallow megathrust and separate largely [...]
On the use of rock physics models for studying the critical zone
Published: 2020-11-12
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology
How effective are rock physics models for relating seismic velocities to the physical properties of sediments, fluids, and cement within the critical zone, and what factors most substantially influence the models’ accuracies? We answer these questions by testing and analyzing the accuracies of seven rock physics models (Hertz-Mindlin, Walton, Jenkins, Digby, stiff sand, soft sand, and contact [...]
The effects of 180 years of aging on the physical and seismic properties of partially saturated sands
Published: 2020-11-12
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology
Constraining how the physical properties and seismic responses of recently deposited sands change with time is important for understanding earthquake site response, subsurface fluid flow, and early stages lithification. Currently, however, there is no detailed (cm-scale) assessment of how sand physical properties and associated seismic velocities evolve over the first two centuries after [...]
Radiocarbon Protocols and First Intercomparison Results from the Chronos 14Carbon-Cycle Facility, University of New South Wales, Sydney, Australia
Published: 2020-11-12
Subjects: Physical Sciences and Mathematics
The Chronos 14Carbon-Cycle Facility is a new radiocarbon laboratory at the University of New South Wales, Australia. Built around an Ionplus 200 kV MIni-CArbon DAting System (MICADAS) Accelerator Mass Spectrometer (AMS) installed in October 2019, the facility was established to address major challenges in the Earth, Environmental and Archaeological sciences. Here we report an overview of the [...]
Evaluating the geochemistry and paired silicon and oxygen isotope record of quartz in siliceous rocks from the ~3 Ga Buhwa Greenstone Belt, Zimbabwe, a critical link to deciphering the Archean silica cycle
Published: 2020-11-09
Subjects: Physical Sciences and Mathematics
The balance of the Archean silica cycle links fundamentally to large scale processes that govern the composition of the ocean. Shifting contributions from continental or hydrothermal inputs of silica to the ocean is commonly recorded in silica-rich chemical precipitates. Such information is critical to interpreting primordial conditions in early life environments but reading the archive of [...]
Examining the impact of the Great Barrier Reef on tsunami propagation using numerical simulations
Published: 2020-11-09
Subjects: Other Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Coral reefs may provide a beneficial first line of defence against tsunami hazards, though this is currently debated. Using a fully nonlinear, Boussinesq propagation model, we examine the buffering capacity of the Great Barrier Reef against tsunamis triggered by several hypothetical sources: a series of far-field, Solomon Islands earthquake sources of various magnitudes (Mw 8.0, Mw 8.5, and Mw [...]
Fault inversion can accommodate ground deformation above inflating igneous sills
Published: 2020-11-09
Subjects: Physical Sciences and Mathematics
Magma emplacement is commonly accommodated by uplift of the overburden and free surface. By assuming this deformation is purely elastic, we can invert the shape and kinematics of ground deformation to model the geometry and dynamics of underlying intrusions. However, magma emplacement can be accommodated by viscoelastic and/or inelastic processes. We use 3D seismic reflection data to reconstruct [...]
Surface slip distributions and geometric complexity of intraplate reverse-faulting earthquakes
Published: 2020-11-09
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Earthquake ground surface ruptures provide insights into faulting mechanics and inform seismic hazard analyses. Surface ruptures for eleven historical (1968 to 2018) moment magnitude (Mw) 4.7 to 6.6 reverse earthquakes in Australia are analyzed using statistical techniques and compared to magnetic, gravity, and stress trajectory datasets. Of the total combined (summative) length of all surface [...]