Preprints
Filtering by Subject: Earth Sciences
Mangrove pollen of Indonesia and its suitability as a sea-level indicator
Published: 2018-10-26
Subjects: Earth Sciences, Environmental Sciences, Geography, Physical and Environmental Geography, Physical Sciences and Mathematics, Social and Behavioral Sciences
We investigated the mangroves of Southeast Sulawesi, Indonesia, to assess their potential as proxies for reconstructing sea level during the Holocene. Initial investigations confirmed that the mangrove species demonstrate zonations parallel to the shoreline and are dominated by the family Rhizophoraceae with Avicennia, Heritiera and Sonneratia also important constituents of the mangroves. We [...]
Spectral Mixture Analysis as a Unified Framework for the Remote Sensing of Evapotranspiration
Published: 2018-10-25
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Other Earth Sciences, Physical Sciences and Mathematics, Water Resource Management
This analysis proposes a unified framework for estimation of evapotranspiration (ET) using spectral mixture analysis (SMA) based on globally standardized substrate, vegetation, and dark (SVD) endmembers (EMs). Using all available Landsat 8 scenes from a month in the peak growing season (June) in a diverse 90 x 120 km region in northern California, we characterize the relationship between each of [...]
Flow-Substrate Interactions in Aggrading and Degrading Submarine Channels
Published: 2018-10-24
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geology, Geomorphology, Other Civil and Environmental Engineering, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Connecting real time measurements of current-bed interactions to the temporal evolution of submarine channels can be extremely challenging in natural settings. We present a suite of physical experiments that offer insight into the spectrum of interactions between turbidity currents and their channels, from (i) detachment-limited erosion to (ii) transport-limited erosion to (iii) pure deposition. [...]
Initiation and Arrest of Earthquake Ruptures due to Elongated Overstressed Regions
Published: 2018-10-23
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The initiation of natural and induced earthquakes is promoted in fault areas where the shear stress is close to fault strength. In many important situations, these overstressed fault areas (or “asperities”) are very elongated; for example, in the case of a fault intersecting a reservoir subject to fluid-injection, or the stress concentration along the bottom of a seismogenic zone induced by deep [...]
An Evaluation between Time-term, Reciprocal Time and Refraction Tomography Analysis Methods for obtaining 2-D shallow Seismic Velocity Models over Synthetic Traveltimes
Published: 2018-10-22
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Shallow seismic refraction is the principal geophysical method for environmental and engineering site investigations to image the shallow subsurface. We present an assessment of three inversion methods, namely Time-Term inversion, Reciprocal Time methods and Refraction tomography inversion by using commercial software (SeisImager™) by using a synthetic first-arrival-time dataset that was made by [...]
Disruption of Long-Term Effusive-Explosive Activity at Santiaguito, Guatemala
Published: 2018-10-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Rapid transitions in eruptive activity during lava dome eruptions pose significant challenges for monitoring and hazard assessment efforts. A comprehensive understanding of the dynamic evolution of active lava dome systems requires extensive multi-parametric datasets to fully constrain and understand rapid shifts in eruptive behavior, but few such datasets have been compiled. The Santiaguito lava [...]
Advancing global flood hazard simulations by improving comparability, benchmarking, and integration of global flood models
Published: 2018-10-19
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
In recent years, a range of global flood models (GFMs) were developed, each utilizing different process descriptions as well as validation data sets and methods. To quantify the magnitude of these differences, studies assessed the performance of GFMs on the continental and catchment level. Since the default models set-ups resulted in locally marked [...]
Natural and Anthropogenic Controls on Wood Loads in River Corridors of the Rocky, Cascade, and Olympic Mountains, USA
Published: 2018-10-18
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Wood in rivers creates habitat, shapes the morphology of valley bottoms, and acts as a pool of organic carbon (OC). Effective riverine wood management depends on a robust understanding of the spatial distribution of wood throughout river networks. This motivates the analysis of wood load in relation to both reach- and basin-scale processes. We present wood load data coupled with precipitation, [...]
Holocene climate variability of Mesopotamia and its impact on the history of civilisation
Published: 2018-10-18
Subjects: Earth Sciences, Other Earth Sciences, Physical Sciences and Mathematics
Mesopotamia, known as the cradle of civilisation, gave rise to the first state-based urban societies with sophistic political hierarchies. Its rich history full of important cultural achievements was accompanied by fundamental environmental changes over the Holocene. While geo-bio-archives from the broader region reflect slightly varying climate histories, there is a clear consensus on a more [...]
The deposition and alteration history of the northeast Syrtis Major layered sulfates
Published: 2018-10-16
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
Ancient stratigraphy on Isidis Basins western margin records the history of water on early Mars. Noachian units are overlain by layered, basaltic-composition sedimentary rocks that are enriched in polyhydrated sulfates and capped by more resistant units. The layered sulfates – uniquely exposed at northeast Syrtis Major – comprise a sedimentary sequence up to 600-m thick that has undergone a [...]
Paired organic matter and pyrite δ34S records reveal mechanisms of carbon, sulfur, and iron cycle disruption during Ocean Anoxic Event 2
Published: 2018-10-15
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Sulfur (S) isotope compositions of pyrites in the sedimentary record have played an important part in our understanding of biogeochemical cycling in the geologic record. However, the kinetics of pyritization are complex and depend strongly on the reactivity and mineralogy of available iron. As a second major sink for sulfide in anoxic sediments, organic matter (OM) provides essential context for [...]
Wavelet-based analysis of ground deformation coupling satellite acquisitions (Sentinel-1, SMOS) and data from shallow and deep wells in Southwestern France
Published: 2018-10-15
Subjects: Aerospace Engineering, Applied Mathematics, Earth Sciences, Engineering, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics
Acquisitions of the Sentinel-1 satellite are processed and comprehensively analyzed to investigate the ground displacement during a 3-year period above a gas storage site in Southwestern France. Despite quite low vertical displacements (between 4 and 8 mm) compared to the noise level, the local displacements reflects the variations due to charge and discharge during summer and winter periods, [...]
Seismic observation of tsunami at island broadband stations
Published: 2018-10-15
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Previous studies have reported seismic observations of tsunami recorded at island broadband stations. Coastal loading by the tsunami can explain them. For further quantification, we model tsunami propagation assuming an axisymmetric structure: a conical island with a flat ocean floor. The total tsunami wavefield can be represented by superposition between an incident tsunami wave and the [...]
U–Pb dating of mineral deposits: From age constraints to ore-forming processes
Published: 2018-10-12
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
The knowledge of the timing and duration of ore-forming processes are perhaps one of the most desirable pieces of information that geologists require to draw a complete picture of the deposit and to put its genesis into a coherent regional or even global geological framework. In many cases, it represents an essential parameter for establishing detailed genetic models, and can critically impact on [...]
Structure and elasticity of phlogopite under compression: Geophysical implications
Published: 2018-10-10
Subjects: Earth Sciences, Mineral Physics, Physical Sciences and Mathematics
We investigated the response of the crystal structure, lattice parameters, and unit-cell volume of hydrous layered silicate phlogopite at conditions relevant to subduction zone settings. We have used first principles simulation based on density functional theory to calculate the equation of state and full elastic constant tensor. Based on the generalized gradient approximation, the full single [...]