Preprints
Filtering by Subject: Physical Sciences and Mathematics
Australia’s Tinderbox Drought: an extreme natural event likely worsened by human-caused climate change
Published: 2023-10-27
Subjects: Physical Sciences and Mathematics
We examine the characteristics and causes of southeast Australia’s Tinderbox Drought (2017–2019) that preceded the Black Summer fire disaster. The Tinderbox Drought was characterised by cool season rainfall deficits of around –50% in three consecutive years, which was exceptionally unlikely in the context of natural variability alone. The precipitation deficits were initiated and sustained by an [...]
Pacific shoreline erosion and accretion patterns controlled by El Niño/Southern Oscillation
Published: 2023-10-27
Subjects: Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In the Pacific Basin, the El Niño/Southern Oscillation (ENSO) is the dominant mode of interannual climate variability, driving substantial changes in oceanographic forcing and impacting Pacific coastlines. Yet, how sandy coasts respond to these basin-scale changes has to date been limited to a few long-term beach monitoring sites, predominantly on developed coasts. Here we use 38 years of Landsat [...]
High methane emissions from a eutrophic marine coastal basin driven by bubble release from the sediment
Published: 2023-10-25
Subjects: Biogeochemistry, Physical Sciences and Mathematics
The production of methane in coastal sediments and its release to the water column is intensified by anthropogenic eutrophication and bottom water hypoxia, and it is yet uncertain whether methane emissions to the atmosphere will be enhanced. Here, we assess seasonal variations in methane dynamics in a eutrophic, seasonally euxinic coastal marine basin (Scharendijke, Lake Grevelingen). In-situ [...]
Exploring Foundation Models for Seismic Event Processing
Published: 2023-10-24
Subjects: Physical Sciences and Mathematics
Nonproliferation monitoring efforts benefit from a glut of multi-modal data that related research must develop methods to process efficiently. Many of the highest performing methods for predictive modeling rely on a legacy of data curation and labeling that is available from decades of seismic catalog building but may not scale well for future uses. This work explores tools for predictive [...]
Hydrological model skills change with drought severity; insights from multi-variable evaluation
Published: 2023-10-23
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Hydrological models often do not properly simulate streamflow (Q) during extreme events, including droughts. Limited abilities in simulating Q during droughts may arise from a misrepresentation of Q generating processes during these periods, but little research has focused on distributed, process-based models over human-affected areas and extreme events. To shed more light into model consistency [...]
Detection of Hidden Low-Frequency Earthquakes in Southern Vancouver Island with Deep Learning
Published: 2023-10-19
Subjects: Physical Sciences and Mathematics
Low-frequency earthquakes (LFEs) are small-magnitude earthquakes that are depleted in high-frequency content relative to traditional earthquakes of the same magnitude. These events occur in conjunction with slow slip events (SSEs) and can be used to infer the space and time evolution of SSEs. However, because LFEs have weak signals, and the methods used to identify them are computationally [...]
Reproducing the Mid-Piacenzian Warm Period Climate in the 2020s.
Published: 2023-10-17
Subjects: Physical Sciences and Mathematics
The current expectation of climatologists is that levels of atmospheric carbon dioxide (CO2) and other greenhouse gases, such as methane (CH4) and nitrous oxide (N2O), will correspond, in the 2020s, to an increase in mean annual global near-surface atmospheric temperature of less than 1.5°C above the pre-industrial Holocene norm (1750 baseline; atmospheric CO2 = 278 ppm). This paper will argue, [...]
Global ocean spatial suitability for macroalgae offshore cultivation and sinking
Published: 2023-10-17
Subjects: Physical Sciences and Mathematics
Macroalgae offshore cultivation and sinking is considered a potentially practical approach for ocean-based carbon dioxide removal. However, several considerations need to be resolved to assess the effectiveness and sustainability of this approach. Currently, several studies focus on the area required for climate-relevant carbon sequestration through macroalgae cultivation and sinking without [...]
Moving graphs: Predicting barchan dune migration rates from their shapes
Published: 2023-10-17
Subjects: Physical Sciences and Mathematics
In this study, geometric perspectives on sand dune formation and motion are summarized, introduced, and combined to predict time-averaged velocities (migration rates) of barchan dunes directly from their shapes. First, it is proposed that smaller sediment accumulations outpace larger ones due to differences in surface-to-volume ratio. This ratio is defined by a bedform’s wavelength and its [...]
Short-term magma-carbonate interaction: A modelling perspective
Published: 2023-10-17
Subjects: Physical Sciences and Mathematics
The short-term, syn-eruptive interaction of magma with crustal carbonates can largely affect the eruptive style and drive even low-viscosity magmas toward large explosive eruptions. Only a few studies focus on the short-term interaction and the physical processes behind the experimental observations are still poorly understood. In this work, we study for the first time the short-term [...]
What is coastal subsidence?
Published: 2023-10-13
Subjects: Physical Sciences and Mathematics
While major technological advances have made measurements of coastal subsidence more sophisticated, these advances have not always been matched by a thorough examination of what is actually being measured. Here we draw attention to the widespread miscommunication about key concepts in the coastal subsidence literature, much of which revolving around the interplay between sediment accretion, [...]
Future (2015-2100) Antarctic-wide ice-shelf firn air depletion from a statistical firn emulator
Published: 2023-10-13
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Antarctic firn is critical for ice-shelf stability because it stores meltwater that would otherwise pond on the surface. Ponded meltwater increases the risk of hydrofracture, and subsequent potential ice-shelf collapse. Here, we use output from a firn model to build a computationally simpler emulator that uses a random forest to predict ice-shelf firn air content (FAC) based on climate [...]
Limited reversal of regional climate signals in overshoot scenarios
Published: 2023-10-12
Subjects: Physical Sciences and Mathematics
Without stringent reductions in emission of greenhouse gases in the coming years, an exceedance of the 1.5C temperature limit would become increasingly likely. This has given rise to so-called temperature overshoot scenarios, in which the global mean surface air temperature increase above pre-industrial levels exceeds a certain limit, i.e. 1.5C, before bringing temperatures back below that level. [...]
Microbial catabolic and anabolic utilization of hydrocarbons in deep subseafloor sediments of Guaymas Basin
Published: 2023-10-11
Subjects: Physical Sciences and Mathematics
Guaymas Basin, located off the Gulf of California, is a hydrothermally active marginal basin. Due to steep geothermal gradients and localized heating by sill intrusions, microbial substrates like short-chain fatty acids and hydrocarbons are abiotically produced from sedimentary organic matter at comparatively shallow depths. However, the potential of hydrocarbons as microbial substrates for both [...]
The Heavy Mineral Map of Australia Project: A Novel, Rapid, Automated Quantitative Mineralogy Workflow
Published: 2023-10-10
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The Heavy Mineral Map of Australia (HMMA) is the world’s first project aiming to define a continental heavy mineral baseline. It utilises a novel sample processing workflow and automated mineralogy techniques to rapidly generate and analyse mineralogical data from 1315 archived samples of catchment outlet sediments collected from 1186 catchments across the Australian continent. Heavy [...]