Preprints
Filtering by Subject: Physical Sciences and Mathematics
Microstructural controls on the pressure-dependent permeability of Whitby Mudstone
Published: 2018-01-08
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
A combination of permeability and ultrasonic velocity measurements allied with image analysis is used to distinguish the primary microstructural controls on effective-pressure dependent permeability. Permeabilities of cylindrical samples of Whitby Mudstone were measured using the oscillating pore pressure method at confining pressures ranging between 30-95 MPa and pore pressures ranging between [...]
Frontal and lateral submarine lobe fringes: Comparing sedimentary facies, architecture and flow processes
Published: 2018-01-08
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Submarine lobe fringe deposits form heterolithic successions that may include a high proportion of hybrid beds. The identification of lobe fringe successions aids interpretation of paleogeographic setting and the degree of basin confinement. Here, for the first time, the sedimentological and architectural differences between frontal and lateral lobe fringe deposits are investigated. Extensive [...]
Analysis of miscellaneous non-ambergris organic jetsam beach deposits
Published: 2018-01-05
Subjects: Environmental Monitoring, Environmental Sciences, Physical Sciences and Mathematics
The analysis of a number of ad hoc samples of organic beach jetsam by Fourier transform infrared spectroscopy (FTIR), gas chromatography (GC), high temperature GC (HTGC), GC-mass spectrometry (GC-MS) HTGC-MS and derivatisation, is described. Many of these samples were found by members of the public and handed in for analysis in the hope that the material was ambergris. Jetsam ambergris is [...]
Estimating regional flood discharge during Palaeocene-Eocene global warming (submitted)
Published: 2018-01-04
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Geomorphology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Among the most urgent challenges in future climate change scenarios is accurately predicting the magnitude at which precipitation extremes will intensify. Analogous changes have been reported for an episode of millennial scale 5°C warming termed the Palaeocene-Eocene Thermal Maximum (PETM; 56 Ma), providing independent constraints on hydrological response to global warming. However, quantifying [...]
Communicating Unnatural Disasters
Published: 2018-01-02
Subjects: Earth Sciences, Engineering, Environmental Studies, Physical Sciences and Mathematics, Risk Analysis, Social and Behavioral Sciences
Off the back of the 2017 hurricanes we extend the notion of human-influenced meteo-hydro hazards to include deeper geophysical events. We question where to place Human responsibility in a changing world, and we outline ways to bridge the gaps between scientist’s technical knowledge and ‘meaning’ as it is understood by people at risk. This short Op-ed has been rejected by Science after two rounds [...]
Introduction to Geochronology
Published: 2017-12-29
Subjects: Cosmochemistry, Earth Sciences, Geochemistry, Physical Sciences and Mathematics
These lecture notes cover the first half of an Isotope Geology module at University College London that deals with the geochronological aspects of the subject. The notes introduce the basic principles of radioactive decay, mass spectrometry and isotope dilution before discussing the most common geochronometers in use today, including radiocarbon, Rb-Sr, Sm-Nd, U-Pb, Pb-Pb, K-Ar, Ar-Ar, U-Th-He, [...]
Geometry and Kinematics of Salt-detached Ramp Syncline Basins
Published: 2017-12-23
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
Ramp-syncline basins (RSBs) are characterized by asymmetric depocentres that form by translation above flat-ramp extensional faults or salt detachments having basal steps. Both types of RSBs are composed by landward-dipping and expanding strata defined by basinward-dipping axial traces. 3D seismic data from the São Paulo Plateau, Santos Basin, Brazil, image a series of RSBs formed above thick [...]
The role of glacier retreat for Swiss hydropower production
Published: 2017-12-22
Subjects: Earth Sciences, Engineering, Environmental Sciences, Glaciology, Hydrology, Natural Resource Economics, Natural Resources Management and Policy, Physical Sciences and Mathematics, Sustainability, Water Resource Management
High elevation or high latitude hydropower production (HP) strongly relies on water resources that are influenced by glacier melt and are thus highly sensitive to climate warming. Despite of the wide-spread glacier retreat since the development of HP infrastructure in the 20th century, little quantitative information is available about the role of glacier mass loss for HP. We provide the first [...]
Topographic modulation of fault kinematics in the Himalaya and Tibet
Published: 2017-12-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
In many locations in the Himalaya and Tibet, extensional stepovers on strike-slip faults occur beneath pre-existing topographic highs. An influential physical model of orogens, explaining contemporaneous high-elevation normal faulting and low-elevation reverse faulting, holds that horizontal tectonic compression is invariant across the orogen while vertical stress varies with topography, [...]
Exogenic forcing and autogenic processes on continental divide location and mobility -- preprint
Published: 2017-12-21
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Sedimentology
The position and mobility of drainage divides is an expression of exogenic landscape forcing and autogenic channel network processes integrated across a range of scales. At the large scale, represented by major rivers and continental drainage divides, the organization of drainage patterns and divide migration reflects the long-wavelength gradients of the topography, which are exogenically [...]
Slope-fan depositional architecture from high-resolution forward stratigraphic models
Published: 2017-12-18
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Submarine fans in tectonically active continental-slope basins are targets of petroleum exploration and production. These slope fans commonly comprise compensationally stacked sandy and muddy architectural elements, including mass-transport deposits, weakly confined to distributary channel-and-lobe deposits, and leveed-channel deposits. The lateral continuity and vertical connectivity of these [...]
Lake sediment records of persistent organic pollutants and polycyclic aromatic hydrocarbons in Southern Siberia mirror the changing fortunes of the Russian economy over the past 70 years
Published: 2017-12-18
Subjects: Chemistry, Ecology and Evolutionary Biology, Environmental Chemistry, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Terrestrial and Aquatic Ecology
Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) have previously been detected in the surface sediments, water, and endemic organisms of Lake Baikal, a UNESCO World Heritage Site. The Selenga River is the primary source of freshwater to Lake Baikal, and transports pollutants accumulating in the Selenga River basin to the lake. Sources of POPs and PAHs in the [...]
The joint influence of break and noise variance on the break detection capability in time series homogenization
Published: 2017-12-15
Subjects: Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Instrumental climate records of the last centuries suffer from multiple breaks due to relocations and changes in measurement techniques. These breaks are detected by relative homogenization algorithms using the difference time series between a candidate and a reference. Modern multiple changepoint methods use a decomposition approach where the segmentation explaining most variance defines the [...]
Recycling of archaeal biomass as a new strategy for extreme life in Dead Sea deep sediments
Published: 2017-12-15
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Organic Chemistry, Physical Sciences and Mathematics
Archaea and Bacteria that inhabit the deep subsurface (known as the deep biosphere) play a prevalent role in the recycling of sedimentary organic carbon. In such environments, this process can occur over millions of years and requires microbial communities to cope with extremely limited sources of energy. Because of this scarcity, metabolic processes come at a high energetic cost, but the ways [...]
The influence of community recommendations on metadata completeness
Published: 2017-12-14
Subjects: Physical Sciences and Mathematics
Many communities use standard, structured documentation that is machine-readable, i.e. metadata, to make discovery, access, use, and understanding of scientific datasets possible. Organizations and communities have also developed recommendations for metadata content that is required or suggested for their data developers and users. These recommendations are typically specific to metadata [...]