Preprints
Filtering by Subject: Earth Sciences
Antarctic Ice Shelves Lose Most of Their Mass From Shallow Depths
Published: 2020-06-18
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Understanding the processes involved in basal melting of Antarctic ice shelves is important to quantify the rate at which Antarctica will lose mass. Current research of of ice shelf-ocean interaction is almost exclusively guided by satellite derived estimates of Antarctic-wide ice shelf melting, which highlight deep warm water intrusions and melting along ice shelf grounding lines. Here we [...]
A First Constraint on Basal Melt-water Production of the Greenland Ice Sheet
Published: 2020-06-18
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
The Greenland ice sheet is one of the largest sources of sea-level rise since the early 2000s. Basal melt has not been included explicitly in assessments of ice-sheet mass loss so far. Here, we present the first full-coverage estimate of the ice-sheet wide basal melt in Greenland and its recent change through time. We find that presently basal melting contributes at least 22.3 +5/-3 Gt per year [...]
Across-strike asymmetry of the Andes orogen linked to the age and geometry of the Nazca plate
Published: 2020-06-18
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
The spine of Andes – the trace of the highest mountain topography – weaves back and forth, in places near the coastline, in others farther inland. Its position is thought to be partially influenced by the asymmetric distribution of rainfall causing the migration of the topographic divide (i.e. mountain peaks) in favor of the more erosive (wetter) side and consuming the less erosive (drier) side. [...]
Deformation controlled Long-Period seismicity in low cohesion volcanic sediments
Published: 2020-06-18
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Volcano seismicity is an important tool in remotely monitoring and forecasting activity at volcanoes around the world. Volcanic earthquakes show diverse spectral characteristics, with shallow Long Period (Low Frequency) seismicity and long duration tremor generally interpreted as indicators of fluid migration, and as potential precursors to eruption. Here we show that a common low-cohesion [...]
Methane concentrations in streams reveal gas leak discharges in regions of oil, gas, and coal development
Published: 2020-06-18
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Geochemistry, Oil, Gas, and Energy, Physical Sciences and Mathematics, Water Resource Management
As natural gas has grown in importance as a global energy source, leakage of methane (CH4) from wells has sometimes been noted. Leakage of this greenhouse gas is important because it affects groundwater quality and, when emitted to the atmosphere, climate. We hypothesized that streams might be most contaminated by CH4 in the northern Appalachian Basin in regions with the longest history of [...]
The social-ecological dimensions of changing global freshwater availability
Published: 2020-06-18
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
Quantifying physical water security at the global scale remains hampered by a lack of systematically produced observational data. Here we combine the observed trends in global freshwater availability from the recently completed Gravity Recovery and Climate Experiment satellite mission1 with more than a dozen other global datasets and provide the missing observational basis to numerous existing [...]
Seismic constraints on rock damaging in a failing mountain peak: the Hochvogel, Allgäu
Published: 2020-06-18
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Large rock slope failures play a pivotal role in long-term landscape evolution and are a major concern in land use planning and hazard aspects. While the failure phase and the time immediately prior to failure are increasingly well studied, the nature of the preparation phase remains enigmatic. This knowledge gap is due, to a large degree, to difficulties associated with instrumenting high [...]
Intrasalt Structure and Strain Partitioning in Layered Evaporites: Implications for Drilling Through Messinian Salt in the Eastern Mediterranean
Published: 2020-06-18
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
We use 3D seismic reflection data from the Levant margin, offshore Lebanon to investigate the structural evolution of the Messinian evaporite sequence, and how intrasalt strain varies within a thick salt sheet during early-stage salt tectonics. Intra-Messinian reflectivity reveals lithological heterogeneity within the otherwise halite-dominated sequence. This leads to rheological heterogeneity, [...]
The 3D thermal field across the Alpine orogen and its forelands and the relation to seismicity
Published: 2020-06-17
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Temperature exerts a first order control on rock strength, principally via thermally activated creep deformation and on the distribution at depth of the brittle-ductile transition zone. The latter can be regarded as the lower bound to the seismogenic zone, thereby controlling the spatial distribution of seismicity within a lithospheric plate. As such, models of the crustal thermal field are [...]
Seasonal impact-based mapping of compound hazards
Published: 2020-06-17
Subjects: Applied Mathematics, Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Hydrology, Mathematics, Multivariate Analysis, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability
Impact-based, seasonal mapping of compound hazards is proposed. It is pragmatic, identifies phenomena to drive the research agenda, produces outputs relevant to stakeholders, and could be applied to many hazards globally. Illustratively, flooding and wind damage can co-occur, worsening their joint impact, yet where wet and windy seasons combine has not yet been systematically mapped. Here, [...]
Syn-depositional Mesozoic siliciclastic pathways on the Moroccan Atlantic margin linked to evaporite mobilisation
Published: 2020-06-17
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Evaporite mobilisation in evaporite-cored anticlines leads to topographic growth that can alter sedimentary routing in shallow marine environments. This paper analyses two evaporite-cored anticlines perpendicular to the NW Africa coast to understand how their tectonic evolution influenced sediment pathways during the Early to Middle Jurassic and Early Cretaceous exhumation of the Mesozoic margin [...]
Notes on statistical age dispersion in fission-track datasets: the chi-square test, annealing variability, and analytical considerations
Published: 2020-06-13
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
Notes on fission track statistics, the chi-square test, annealing (i.e. fission track age) variability, and analytical bias aimed at a general Earth scientist audience and for users of fission track data
Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice
Published: 2020-06-13
Subjects: Earth Sciences, Electrical and Computer Engineering, Engineering, Glaciology, Physical Sciences and Mathematics, Systems and Communications
Subglacial hydrological systems require innovative technological solutions to access and observe. Wireless sensor platforms can be used to collect and return data, but their performance in deep and fast-moving ice requires quantification. We report experimental results from Cryoegg: a spherical probe that can be deployed into a borehole or moulin and transit through the subglacial hydrological [...]
The Whole Antarctic Ocean Model (WAOM v1.0): Development and Evaluation
Published: 2020-06-13
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The Regional Ocean Modeling System (ROMS), including an ice shelf component, has been applied on a circum-Antarctic domain to derive estimates of ice shelf basal melting. Significant improvements made compared to previous models of this scale are the inclusion of tides and a horizontal spatial resolution of 2 km, which is sufficient to resolve onshelf heat transport by bathymetric troughs and [...]
Global wave-driven beach evolution; consequences for observation strategies
Published: 2020-06-13
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Life Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
It is an illusion to think that one can observe monthly beach behaviour with monthly surveys. Current coastal observation strategies restrict understanding of beach evolution, preventing effective risk mitigation. In this article, we quantify the global spatiotemporal scales of coastal wave changes, which are the known dominant driver of beach evolution. Consequences and recommendations for beach [...]