Preprints
There are 7999 Preprints listed.
Airborne laser scanning proxies of canopy light transmission in forests
Published: 2021-10-29
Subjects: Biodiversity, Biogeochemistry, Computer Sciences, Earth Sciences, Ecology and Evolutionary Biology, Environmental Sciences, Forest Sciences, Life Sciences, Physical Sciences and Mathematics, Plant Sciences, Software Engineering, Statistics and Probability
Reliable estimates of canopy light transmission are critical to understanding the structure and function of vegetation communities but are difficult and costly to attain by traditional field inventory methods. Airborne laser scanning (ALS) data uniquely provide multi-angular vertically resolved representation of canopy geometry across large geographic areas. While previous studies have proposed [...]
Potency density tensor inversion of complex body waveforms with time-adaptive smoothing constraint
Published: 2021-10-28
Subjects: Physical Sciences and Mathematics
Large earthquakes are often accompanied by complex fault rupture, but it has been difficult to reliably estimate such a complex rupture process with conventional waveform analysis tools due to modelling errors originating from limited accuracy of the fault geometry. Recently, a potency density tensor inversion method has been developed to solve this problem; allowing any types of faulting [...]
Constraints on the behaviour and content of volatiles in Galápagos magmas from melt inclusions and nominally anhydrous minerals
Published: 2021-10-29
Subjects: Physical Sciences and Mathematics
Despite their relatively low concentration in most oceanic basalts, volatile species (e.g. H2O, CO2 and S) have a disproportionately large influence on a wide range of mantle and magmatic processes. However, constraining the concentration of H2O (and other volatiles) in basaltic magmas is not straightforward as submarine glass analyses are influenced by assimilation of hydrothermal brines, and [...]
Vertical Deformation and Residual Altimeter Systematic Errors around Continental Australia Inferred from a Kalman-Based Approach
Published: 2021-11-15
Subjects: Earth Sciences, Environmental Monitoring, Other Earth Sciences
We further developed a space-time Kalman approach to estimate time-variable signals in residual altimeter systematic errors and vertical land motion (VLM) around the Australian coast since the 1990s, through combining multi-mission absolute sea-level (ASL), relative sea-level (RSL) from tide gauges (TGs) and GPS heights records. Our results confirmed continent-wide subsidence and TG-specific VLMs [...]
On the impact of urbanisation on CO2 emissions
Published: 2021-11-01
Subjects: Physical Sciences and Mathematics
We use a globally consistent, time-resolved data set of CO2 emission proxies to quantify urban CO2 emissions in 91 cities. We decompose emission trends into contributions from changes in urban extent, population density and per capita emission. We find that urban CO2 emissions are increasing everywhere but that the dominant contributors differ according to development level. A cluster analysis of [...]
Hemispheric geochemical dichotomy of the mantle is a legacy of austral supercontinent assembly and deep subduction of continental crust
Published: 2021-11-01
Subjects: Physical Sciences and Mathematics
Oceanic hotspots with extreme enriched mantle radiogenic isotopic signatures—including high 87Sr/86Sr and low 143Nd/144Nd indicative of ancient subduction of continental crust—are restricted to the southern hemispheric mantle. However, the mechanisms responsible for concentrating subducted continental crust in the austral mantle are unknown. We show subduction of sediments and subduction eroded [...]
From offshore to onshore probabilistic tsunami hazard assessment via efficient Monte-Carlo sampling
Published: 2021-11-01
Subjects: Earth Sciences, Other Earth Sciences
Offshore Probabilistic Tsunami Hazard Assessments (offshore PTHAs) provide large-scale analyses of earthquake-tsunami frequencies and uncertainties in the deep ocean, but do not provide high-resolution onshore tsunami hazard information as required for many risk-management applications. To understand the implications of an offshore PTHA for the onshore hazard at any site, in principle the tsunami [...]
Introducing StreamProfilerApp, a web application for near-global, exploratory, longitudinal river profile analysis
Published: 2021-11-03
Subjects: Earth Sciences, Education
Stream profile analysis has been used extensively in the earth sciences. In the past, exploration of stream profiles has required downloading and processing Digital Elevation Models (DEMs) for specific areas, which limits the scope of exploratory analysis. Presented here is a web application designed to analyze stream profiles at 90m resolution at a near-global scale. Based on the Hydrosheds [...]
Toward the understanding of saline water intrusion and nutrient flushing in Lake Nokoué
Published: 2021-11-03
Subjects: Life Sciences
To understand the salinity dynamic at the outlet of Lake Nokoué and to simulate the nutrient flushing from this lake into the Atlantic Ocean, a 2D hydrodynamic model was designed with Mike 21. The choice of the Mike 21 was motivated by the long practice that decision-makers in Benin have with this software. The Hydrodynamics (HD) module simulated water level variations and flows in response, [...]
Subsurface temperature from seismic reflections: application to the post break up sequence offshore Namibia
Published: 2021-11-05
Subjects: Earth Sciences, Geology, Geophysics and Seismology
Accurate estimations of present-day subsurface temperatures are of critical importance to the energy industry, in particular with regards to geothermal energy and petroleum exploration. In frontier basins, the subsurface temperature regime can give an indication of the hydrocarbon potential of source horizons. The Lüderitz Basin, offshore Namibia, is a frontier deep water basin located on a [...]
Regional analysis of climate projections using Bias Corrected spatial disaggregated super-resolution convolutional neural networks
Published: 2021-11-04
Subjects: Engineering, Life Sciences, Physical Sciences and Mathematics
Climate change is very crucial for ecological systems and society. But Global climate models run at coarse spatial resolution which is difficult to do regional analysis. Regional-scale projections can be obtained by a technique called statistical downscaling which uses past data to find out the high resolution and low-resolution mapping. There are many methods for statistical downscaling of [...]
Collapse wedges in periglacial eolian sands imply Late Pleistocene paleoseismic activity of the Vienna Basin Transfer Fault (western Slovakia)
Published: 2021-11-04
Subjects: Physical Sciences and Mathematics
Seismic hazard assessment is an important issue in geological research. Paleoseismological studies of the depositional record contribute significantly to our knowledge of earthquake recurrence over geological time, the distribution of seismically triggered deformations being an area of research that sheds light on temporal patterns of seismic activity. This paper describes soft sediment [...]
GESLA Version 3: A major update to the global higher-frequency sea-level dataset
Published: 2021-11-05
Subjects: Oceanography
This paper describes a major update to the quasi-global, higher-frequency sea-level dataset known as GESLA (Global Extreme Sea Level Analysis). Versions 1 (released 2009) and 2 (released 2016) of the dataset have been used in many published studies, across a wide range of oceanographic and coastal engineering-related investigations concerned with evaluating tides, storm surges, extreme sea levels [...]
WlCount: Geological lamination detection and counting using an image analysis approach
Published: 2021-11-08
Subjects: Earth Sciences, Longitudinal Data Analysis and Time Series, Speleology, Stratigraphy
The manual identification and count of laminae in layered textures is a common practice in the study of geological records, which can be time consuming and carry large uncertainty for dense or disturbed lamina textures. We present here a novel image analysis approach to detect and count laminae in geoscientific imagery, called WlCount. Based on Dynamic Time Warping and Wavelet analysis, WlCount [...]
Nonlinear time series analysis of palaeoclimate proxy records
Published: 2021-11-08
Subjects: Applied Statistics, Climate, Dynamic Systems, Earth Sciences, Geology, Longitudinal Data Analysis and Time Series, Multivariate Analysis, Non-linear Dynamics, Physical Sciences and Mathematics, Sedimentology, Statistical, Nonlinear, and Soft Matter Physics
Identifying and characterising dynamical regime shifts, critical transitions or potential tipping points in palaeoclimate time series is relevant for improving the understanding of often highly nonlinear Earth system dynamics. Beyond linear changes in time series properties such as mean, variance, or trend, these nonlinear regime shifts can manifest as changes in signal predictability, [...]