Preprints
Filtering by Subject: Earth Sciences
Streamflow depletion from groundwater pumping in contrasting hydrogeological landscapes: Evaluation and sensitivity of a new management tool
Published: 2020-04-29
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Sustainability, Water Resource Management
Groundwater pumping can reduce streamflow by reducing groundwater discharge and/or inducing streamflow infiltration, which together are referred to as streamflow depletion. Recently, analytical depletion functions (ADFs) have been suggested as rapid and accurate tools for streamflow depletion assessment, but their performance has only been tested in a few hydrogeological settings. To evaluate [...]
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 [...]
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, [...]
Using thermal springs to quantify deep groundwater flow and its thermal footprint in the Alps and North American orogens
Published: 2020-04-29
Subjects: Earth Sciences, Geology, Hydrology, Physical Sciences and Mathematics
The extent of deep groundwater flow in mountain belts and its thermal effects are uncertain. Here, we use a new database of discharge, temperature and composition of thermal springs in the Alps to estimate the extent of deep groundwater flow and its contribution to the groundwater and heat budget. The results indicate that springs are fed exclusively by meteoric water and make up 0.1% of the [...]
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
Downscaling digital soil maps using electromagnetic induction and aerial imagery
Published: 2020-04-17
Subjects: Earth Sciences, Physical Sciences and Mathematics, Soil Science
Coarse-resolution soil maps at regional to national extents are often inappropriate for mapping intra-field variability. At the same time, sensor data, such as electromagnetic induction measurements and aerial imagery, can be highly useful for mapping soil properties that correlate with electrical conductivity or soil color. However, maps based on these data nearly always require calibration with [...]
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 [...]
Lateral variations in lower crustal strength control the temporal evolution of mountain ranges: examples from south-east Tibet
Published: 2020-04-17
Subjects: Earth Sciences, Geochemistry, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Controversy surrounds the rheology of the continental lithosphere, and how it controls the evolution and behaviour of mountain ranges. In this study, we investigate the effect of lateral contrasts in the strength of the lower crust, such as those between cratonic continental interiors and weaker rocks in the adjacent deforming regions, on the evolution of topography. We combine numerical [...]
Evaluating UK natural hazards: the national risk assessment
Published: 2020-04-15
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Despite its relatively temperate climate and stable geography, natural hazards present multiple risks to human activity in the UK. These range from small-scale local occurrences, such as landslides, through regional incidents, such as flooding, to major high impact, low probability events, such as space weather. The impacts of such hazards can be wide-ranging but may include disruption to [...]