Preprints

Filtering by Subject: Other Earth Sciences

Are magnetic stripes on the Cuvier Abyssal Plain (offshore NW Australia) diagnostic of oceanic crust?

Matthew T. Reeve, Craig Magee, Ian Bastow, Carl McDermott, Christopher Aiden-Lee Jackson, Rebecca Bell, Julie Prytulak

Published: 2019-06-22
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure

Magnetic stripes have long been used to define the presence and age of oceanic crust. However, continental crust heavily intruded by magma can record magnetic reversals akin to those observed in oceanic crust. We re-evaluate the nature of the Cuvier Abyssal Plain (CAP), offshore NW Australia, which hosts magnetic stripes and has previously been defined as oceanic crust. We use magnetic, 2D [...]

Holocene sedimentary record and coastal evolution in the Makran subduction zone (Iran)

Raphaël Normand, Guy Simpson, Frederic Herman, Rabiul Haque Biswas, Abbas Bahroudi

Published: 2019-05-15
Subjects: Earth Sciences, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology

The Makran coast displays evidence of surface uplift since at least the Late Pleistocene, but it remains uncertain whether this displacement is accommodated by creep on the subduction interface, or in a series of large earthquakes. Here, we address this problem by looking at the short term (Holocene) history of continental vertical displacements recorded in the geomorphology and sedimentary [...]

Using a Superconducting Gravimeter in Support of Absolute Gravity Campaigning — A feasibility study

Hans-Georg Scherneck, Marcin Rajner

Published: 2019-05-13
Subjects: Earth Sciences, Engineering, Life Sciences, Other Earth Sciences, Physical Sciences and Mathematics

Preparing for joint analysis of absolute gravity (AG) campaigns, this report investigates whether a stationary superconducting gravimeter (SCG) can provide a long-term stable measurement of site-dependent perturbations that help in reduction to the local value of little-$g$ and its secular rate of change. The crucial element concerns the discrimination of instrumental drift components from trends [...]

On the automatic and a priori design of unstructured mesh resolution for coastal ocean circulation models

Keith J. Roberts, William James Pringle, Joannes J. Westerink, Marite Teresa Contreras, Damrongsak Wirasaet

Published: 2019-05-10
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Civil and Environmental Engineering, Other Earth Sciences, Physical Sciences and Mathematics

This study investigates the design of unstructured mesh resolution and its impact on the modeling of barotropic tides along the United States East Coast and Gulf Coast (ECGC). A discrete representation of a computational ocean domain (mesh design) is necessary due to finite computational resources and an incomplete knowledge of the physical system (e.g., shoreline and seabed topography). The [...]

Three Billion Year Secular Evolution of the Triple Oxygen Isotope Composition of Marine Chert

Justin A. Hayles, Laurence Y Yeung, Martin Homann, Asmita Banerjee, Hehe Jiang, Bing Shen, Cin-Ty A. Lee

Published: 2019-05-07
Subjects: Earth Sciences, Geochemistry, Other Earth Sciences, Physical Sciences and Mathematics

The 18O/16O ratios of ancient marine minerals show a puzzling increase over geologic time. Long-term changes in temperature, seawater 18O/16O ratios, and post-depositional overprinting can all explain this trend, but few tracers can distinguish between these scenarios. Here, we report high-precision 18O/16O and 17O/16O ratios of cherts through 3.4 Ga of Earth′s history. We find that Phanerozoic [...]

Application of multivariate statistical methods to hydrogeological property parameterisation from geotechnical and geophysical data

Gareth Digges La Touche, Sarah Alexander, Jo Birch, Xander Gwynn

Published: 2019-04-26
Subjects: Earth Sciences, Environmental Sciences, Geology, Hydrology, Other Earth Sciences, Physical Sciences and Mathematics, Water Resource Management

Hydrogeological data sets are often relatively sparse compared to the scale of investigation, resulting in degrees of uncertainty which, although constrained, may be considered as not acceptable for achieving the desired precision in numerical modelling. The potential use of multivariate statistical methods in identifying correlations between geotechnical properties of the rock mass and hydraulic [...]

Characterising strong force networks produced during granular shear using percolation methods: Revealing the bridge between local grain scale processes and macroscopic sliding

Karen Mair, Espen Jettestuen, Steffen Abe

Published: 2019-04-08
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics, Physics, Tectonics and Structure

Faults, landslides and subglacial till often contain accumulations of granular debris. Their macroscopic motion is at least to some extent determined by the processes operating in this sheared granular material. A valid question in these environments is how the local behaviour at the individual granular contacts actually sums up to influence macroscopic sliding. Laboratory experiments and [...]

Determining cooling rates from mica 40Ar/39Ar thermochronology data: effect of cooling path shape

Clare Warren, Christopher McDonald, Felix Hanke, Julian Chard

Published: 2019-04-02
Subjects: Earth Sciences, Geochemistry, Geology, Other Earth Sciences, Physical Sciences and Mathematics

Tectonic models are commonly underpinned by metamorphic cooling rates derived from diffusive-loss thermochronology data. Such cooling ages are usually linked to temperature via Dodson’s 1973 closure temperature (TC) formulation, which specifies a 1/time-shaped cooling path. Geologists, however, commonly discuss cooling rates as a linear temperature/time shape. We present the results of a series [...]

Agriculture-aquaculture transitions on the lower Ganges-Brahmaputra Delta, 1972-2017

Daniel Sousa, Christopher Small

Published: 2019-03-25
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Natural Resources Management and Policy, Other Earth Sciences, Other Environmental Sciences, Physical Sciences and Mathematics, Sustainability

Recent decades have seen a considerable increase in shrimp aquaculture in tropical and subtropical developing countries. This practice is controversial due to its potential for serious economic, food security, and environmental impacts. Of particular concern is the widespread practice of intensive aquaculture in and near mangrove ecosystems where many shrimp species spawn. However, while [...]

The Impact of Melting Ice Sheets on Future Global Climate

Dimitri Defrance, Thibault Catry, Amélie Rajaud, Nadine Dessay, Benjamin Sultan

Published: 2019-03-22
Subjects: Climate, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics, Physics

That is a preprint of an article suubmitted at Applied Greography (20tf of March 19). Climate change studies in the last decades have been based on Global Climate Models (GCM), and the distribution of climatic regions over time extracted from these models can be represented using the Köppen climatic classification. The Köppen approach predicts the distribution of biomes worldwide on the basis of [...]

Human-induced fire regime shifts during 19th century industrialization: a robust fire regime reconstruction using northern Polish lake sediments

Elisabeth Dietze, Dariusz Brykała, Laura T. Schreuder, Krzysztof Jażdżewski, Olivier Blarquez, Achim Brauer, Michael Dietze, Milena Obremska, Florian Ott, Anna Pieńczewska

Published: 2019-02-22
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Other Earth Sciences, Physical Sciences and Mathematics

Fire regime shifts are driven by climate and natural vegetation changes, but can be strongly affected by human land management. Yet, it is poorly known how exactly humans have influenced fire regimes prior to active wildfire suppression. Among the last 250 years, the human contribution to the global increase in fire occurrence during the mid-19th century is especially unclear, as data sources are [...]

Minibasin depocentre migration during diachronous salt welding, offshore Angola

Zhiyuan Ge, Robert Gawthorpe, Atle Rotevatn, Leo Zijerveld, Christopher Aiden-Lee Jackson, Ayodeji Oluboyo

Published: 2019-02-16
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure

Salt tectonics is an important part of the geological evolution of many continental margins, yet the four-dimensional evolution of the minibasins, the fundamental building block of these and many other salt basins, remains poorly understood. Using high-quality 3D seismic data from the Lower Congo Basin, offshore Angola we document the long-term (>70 Myr) dynamics of minibasin subsidence. We [...]

The Stratigraphic Record of Minibasin Subsidence, Precaspian Basin, Kazakhstan

Christopher Aiden-Lee Jackson, Oliver B Duffy, Naiara Fernandez, Timothy Dooley, Michael R Hudec, Martin P.A. Jackson, George Berg

Published: 2019-02-14
Subjects: Earth Sciences, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure

Minibasins are fundamental components of many salt-bearing sedimentary basins, where they may host large volumes of hydrocarbons. Although we understand the basic mechanics governing their subsidence, we know surprisingly little of how minibasins subside in three-dimensions over geological timescales, or what controls such variability. Such knowledge would improve our ability to constrain initial [...]

Globally Standardized MODIS Spectral Mixture Models

Daniel Sousa, Christopher Small

Published: 2019-01-31
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Other Earth Sciences, Physical Sciences and Mathematics

This analysis presents standardized substrate, vegetation, and dark (S, V, & D) endmembers (EMs) for spectral mixture analysis (SMA) of MODIS daily nadir-looking BRDF-adjusted reflectance (daily NBAR) data. MODIS daily NBAR EMs are derived from a diverse collection of over 43 million MODIS spectra spanning 6 continents and all non-polar biomes. EM spectra found in the study are comparable to [...]

Factor Analysis by R Programming to Assess Variability Among Environmental Determinants of the Mariana Trench

Polina Lemenkova

Published: 2019-01-28
Subjects: Computer Sciences, Earth Sciences, Education, Engineering, Environmental Monitoring, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Graphics and Human Computer Interfaces, Life Sciences, Marine Biology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Geography, Other Oceanography and Atmospheric Sciences and Meteorology, Physical and Environmental Geography, Physical Sciences and Mathematics, Programming Languages and Compilers, Remote Sensing, Science and Mathematics Education, Sedimentology, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure, Water Resource Management

The aim of this work is to identify main impact factors affecting variations in the geomorphology of the Mariana Trench which is the deepest place of the Earth, located in the west Pacific Ocean: steepness angle and structure of the sediment compression. The Mariana Trench presents a complex ecosystem with highly interconnected factors: geology (sediment thickness and tectonics including four [...]

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