Preprints
There are 6976 Preprints listed.
Setting up the preservation of fluvial channel belts
Published: 2020-04-29
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Subsidence alone is often too slow to create the necessary relief needed to preserve continuous channel belts over 10s of km, as are often observed in outcrops on Earth and Mars, as well as subsurface seismic volumes. However, an alternative source of topographic relief exists along US Gulf of Mexico and SE Atlantic coastal plains, which are regions generally considered flat. Alluvial ridges, [...]
Predicting outbreak-level tornado counts and casualties from environmental variables
Published: 2020-04-30
Subjects: Atmospheric Sciences, Earth Sciences, Life Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Environmental variables are used routinely in forecasting when and where an outbreak of tornadoes are likely to occur, but more work is needed to understand how characteristics of severe weather outbreaks vary with the larger scale environmental factors. Here the authors demonstrate a method to quantify `outbreak-level tornado and casualty counts with respect to variations in large-scale [...]
Constraining global changes in temperature and precipitation from observable changes in surface radiative heating
Published: 2020-04-30
Subjects: Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
Changes in the atmospheric composition alter the magnitude and partitioning between the downward propagating solar and atmospheric longwave radiative fluxes heating the Earths surface. These changes are computed by radiative transfer codes in Global Climate Models and measured with high precision at surface observation networks. Changes in radiative heating signify changes in the global surface [...]
Runout of rock avalanches limited by basal friction but controlled by fragmentation
Published: 2020-04-22
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Rock avalanches display exceptionally long runouts, which are found to correlate with their volume and attributed to size dependent dynamic lowering of the effective basal friction. However, even for similar volumes, runouts are seen to span several orders of magnitude suggesting additional controlling factors. Here, we document experiments with analogue models of rock avalanches aimed at testing [...]
Quantitative analysis of a footwall-scarp degradation complex and syn-rift stratigraphic architecture, Exmouth Plateau, NW Shelf, offshore Australia
Published: 2020-04-29
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Interactions between footwall-, hangingwall- and axial-derived depositional systems make syn-rift stratigraphic architecture difficult to predict, and preservation of net-erosional source landscapes is limited. Distinguishing between deposits derived from fault-scarp degradation (consequent systems) and those derived from long-lived catchments beyond the fault block crest (antecedent systems) is [...]
Global projections of compound coastal meteorological extremes
Published: 2020-04-29
Subjects: Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Compound coastal and inland flooding can result in catastrophic impacts in densely populated low-lying coastal areas. The dynamics and interactions between the underlying meteorological drivers in view of climate change are not fully understood at global scale. Here, we show that under a high emissions scenario the concurrence probability of extreme meteorological tides and inland precipitation [...]
Modeling the spatial dynamics of marsh ponds in New England salt marshes
Published: 2020-04-27
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Ponds are common features on salt marshes, yet it is unclear how they affect large-scale marsh evolution. We developed a spatially explicit model that combines cellular automata for pond formation, expansion, and drainage, and partial differential equations for elevation dynamics. We use the mesotidal Barnstable marsh (MA, USA) as a case study, for which we measured pond expansion rate by remote [...]
Inter-model spread in the pattern effect and its contribution to climate sensitivity in CMIP5 and CMIP6 models
Published: 2020-04-24
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Radiative feedbacks depend on the spatial patterns of sea-surface temperature (SST) and thus can change over time as SST patterns evolve – the so-called ‘pattern effect’. This study investigates inter-model differences in the magnitude of the pattern effect and how these differences contribute to the spread in the effective equilibrium climate sensitivity (ECS) within CMIP5 and CMIP6 models. [...]
A seismic monitoring approach to detect and quantify river sediment mobilisation by steelhead redd-building activity
Published: 2020-04-20
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The role of spawning salmonids in altering river bed morphology and sediment transport is significant yet poorly understood. This is due, in large part, to limitations in monitoring the redd-building process in a continuous and spatially extended way. A complementary approach may be provided through the use of a small seismic sensor network analysing the ground motion signals generated by the [...]
Using large-scale NO2 data from citizen science for air quality compliance and policy support
Published: 2020-04-21
Subjects: Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics
Citizen science projects that monitor air quality have recently drastically expanded in scale. Projects involving thousands of citizens generate spatially dense datasets using low-cost passive samplers for nitrogen dioxide (NO2), which complement data from the sparse reference network operated by environmental agencies. However, there is a critical bottleneck in using these citizen-derived [...]
Spontaneous Cyclogenesis without Radiative and Surface-Flux Feedbacks
Published: 2020-04-18
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Tropical cyclones (TCs) are among the most intense and feared storms in the world. What physical processes lead to cyclogenesis remains the most mysterious aspect of TC physics. Here, we study spontaneous TC genesis in rotating radiative-convective equilibrium using cloud-resolving simulations over an f-plane with constant sea-surface temperature. Previous studies proposed that spontaneous TC [...]
Modelling high-frequency seismograms at ocean bottom seismometers: effects of heterogeneous structures on source parameter estimation for small offshore earthquakes and shallow low-frequency tremors
Published: 2020-04-18
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The source characteristics of offshore seismic events, especially regular (or fast) and slow earthquakes, can provide key information on their source physics and frictional conditions at the plate boundary. Due to strong three-dimensional heterogeneities in offshore regions, such as those relating to seawater, accretionary prism, and small-scale velocity heterogeneity, conventional methods using [...]
Palaeotidal atlas of the UK for the last 10,000 years
Published: 2020-04-18
Subjects: Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Over the past 10,000 years the UK has seen dramatic changes to its coastline due to sea-level rise. Past changes in sea level can be estimated from analysis of sedimentary deposits, including any microfossil assemblages found within. Once dated and the elevation is know, these data become sea level index points (SLIPs). In recreating past sea level in this way there is an implicit assumption of [...]
Lateral variability in strain along a mass-transport deposit (MTD) toewall: a case study from the Makassar Strait, offshore Indonesia
Published: 2020-04-18
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology
Contractional features characterise the toe domain of mass-transport deposits (MTDs). Their frontal geometry is typically classified as frontally-confined or frontally-emergent. However, it remains unclear how frontal emplacement style and contractional strain within an MTD can vary along strike. We use bathymetry and 3D seismic reflection data to investigate lateral variability of frontal [...]
Flow directions of rivers are set by the mantle
Published: 2020-04-17
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Large rivers play crucial roles in determining loci of civilisation, natural resources and biodiversity. The positions of their mouths control nutrient and sediment supply to oceans. The paths that rivers take across the Earth’s surface varies considerably with scale. For example, at large scales big North American rivers (e.g. Mississippi, Colorado, Columbia) have simple flow paths that can be [...]