Preprints
Filtering by Subject: Earth Sciences
Ratio-to-moving-average seismograms: a strategy for improving correlation detector performance
Published: 2017-11-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Correlation detectors are becoming a standard method for identifying seismic signals from repeating sources. These highly sensitive, source-specific detectors frequently facilitate a reduction in the detection threshold by around an order of magnitude. Detections are typically declared when the value of the correlation coefficient (CC), or a related statistic, exceeds significantly some measure [...]
Improvements to Seismic Monitoring of the European Arctic Using Three-Component Array Processing at SPITS
Published: 2017-11-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The detectability of low magnitude seismic events in the European Arctic is determined primarily by the small-aperture International Monitoring System arrays ARCES and SPITS. In August 2004, the SPITS array was upgraded to a broadband array with an increase in the sampling rate from 40 to 80 Hz. Most important, however, for the detection and location of small-magnitude seismic events was the [...]
Seismic Monitoring of the North Korea Nuclear Test Site Using a Multichannel Correlation Detector
Published: 2017-11-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
North Korea announced a second nuclear test on 25 May 2009, the first having taken place on October 9, 2006. Both tests were detected by the global seismic network of the Comprehensive nuclear Test-Ban-Treaty Organisation. We apply a correlation detector using a 10-s signal template from the 2006 test on the MJAR array in Japan to: 1) assess the potential for automatically detecting subsequent [...]
Different frequencies and triggers of canyon filling and flushing events in Nazaré Canyon, offshore Portugal
Published: 2017-11-09
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Submarine canyons are one of the most important pathways for sediment transport into ocean basins. For this reason, understanding canyon architecture and sedimentary processes has importance for sediment budgets, carbon cycling, and geohazard assessment. Despite increasing knowledge of turbidity current triggers, the down-canyon variability in turbidity current frequency within most canyon [...]
Pseudotachylyte as field evidence for lower crustal earthquakes during the intracontinental Petermann Orogeny (Musgrave Block, Central Australia)
Published: 2017-11-09
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Geophysical evidence for lower continental crustal earthquakes in almost all collisional orogens is in conflict with the widely accepted notion that rocks, under high grade conditions, should flow rather than fracture. Pseudotachylytes are remnants of frictional melts generated during seismic slip and can therefore be used as an indicator of former seismogenic fault zones. The Fregon Domain in [...]
Quantifying closed-basin lake temperature and hydrology by inversion of oxygen isotope and trace element paleoclimate records
Published: 2017-11-09
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Physical Sciences and Mathematics
Lake systems are important paleoclimate archives that preserve ecosystem and hydrologic responses to critical periods in Earth history, such as carbon cycle perturbations and glacial-interglacial cycles. Geochemical measurements of biogenic carbonate (for example, δ18O, δ13C, 87Sr/86Sr, [Li], [U], [Sr], and [Mg]) are indicators of hydrologic variability in lake systems throughout the geologic [...]
Global Sensitivity Analysis of Parameter Uncertainty in Landscape Evolution Models
Published: 2017-11-09
Subjects: Earth Sciences, Geomorphology, Hydrology, Life Sciences, Physical Sciences and Mathematics
Landscape Evolution Models have a long history of use as exploratory models, providing greater understanding of the role large scale processes have on the long-term development of the Earth’s surface. As computational power has advanced so has the development and sophistication of these models. This has seen them applied at increasingly smaller scale and shorter-term simulations at greater [...]
Distribution of discontinuous mudstone beds within wave-dominated shallow-marine deposits: Star Point Sandstone and Blackhawk Formation, Eastern Utah, USA
Published: 2017-11-08
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Deposits of wave-dominated shorelines are typically considered to act as relatively simple hydrocarbon reservoirs and are commonly modeled as “tanks of sand”. However, important heterogeneities that can act as barriers to fluid flow occur at the parasequence, bedset and bed scales, especially in viscous oil or low permeability oil fields. Heterogeneities at the parasequence and bedset scale have [...]
The detection of low magnitude seismic events using array-based waveform correlation
Published: 2017-11-08
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
It has long been accepted that occurrences of a known signal are most effectively detected by cross-correlating the incoming data stream with a waveform template. Such matched signal detectors have received very little attention in the field of detection seismology because there are relatively few instances in which the form of an anticipated seismic signal is known a priori. Repeating events in [...]
The European Arctic: A Laboratory for Seismoacoustic Studies
Published: 2017-11-08
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We describe the seismoacoustic monitoring network in Fennoscandia and North West Russia and present how it is being used to characterize infrasound studies in that part of the world. The history of the infrasound array network is presented, together with a description of array processing considerations, and examples of infrasound signals recorded from repeating explosions.
Collinearity assessment of geocentre coordinates derived from multi-satellite SLR data
Published: 2017-11-08
Subjects: Earth Sciences, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics
Of the three satellite geodetic techniques contributing to the International Terrestrial Reference Frame (ITRF), Satellite Laser Ranging (SLR) is generally held to provide the most reliable time series of geocentre coordinates and exclusively defines the ITRF origin. Traditionally, only observations to the two LAser GEOdynamics Satellite (LAGEOS) and Etalon pairs of satellites have been used for [...]
Geostatistical modelling of cyclic and rhythmic facies architectures
Published: 2017-11-08
Subjects: Applied Statistics, Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Statistics and Probability
A pluri-Gaussian method is developed for facies variables in three dimensions to model vertical cyclicity, related to facies ordering, and rhythmicity. Cyclicity is generally characterized by shallowing or deepening-upward sequences and rhythmicity by a low range of variability in cycle thicknesses. Both of these aspects are commonly observed in shallow-marine carbonate successions, especially [...]
Environmental signal propagation in sedimentary systems across timescales
Published: 2017-11-08
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Review of concepts of environmental signal (climate, tectonics, anthropogenic, etc.) propagation in sedimentary systems from source to sink.
Understanding snow hydrological processes through the lens of stable water isotopes
Published: 2017-11-07
Subjects: Earth Sciences, Environmental Sciences, Glaciology, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Snowfall may have different stable isotopic compositions compared to rainfall, allowing its contribution to potentially be tracked through the hydrological cycle. This review summarizes the state of knowledge of how different hydro-meteorological processes affect the isotopic composition of snow, and, through selected examples, discusses how stable water isotopes can provide a better [...]
Sequential growth of deformation bands in carbonate grainstones in the hangingwall of an active growth fault: Implications for deformation mechanisms in different tectonic regimes
Published: 2017-11-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Deformation bands in porous sandstones have been extensively studied for four decades, whereas comparatively less is known about deformation bands in porous carbonate rocks, particularly in extensional settings. Here, we investigate porous grainstones of the Globigerina Limestone Formation in Malta, which contain several types of deformation bands in the hangingwall of the Maghlaq Fault: (i) [...]