Preprints
There are 6155 Preprints listed.
LASIF: LArge-scale Seismic Inversion Framework, an updated version
Published: 2021-01-07
Subjects: Geophysics and Seismology, Numerical Analysis and Scientific Computing, Software Engineering
Recent methodological advances and increases in computational power have made it feasible to perform full-waveform inversions (FWI) of large domains while using more sources. This trend, along with the increasing availability of seismic data has led to an explosion of the data volumes that can, and should, be used within an inversion. Similar to machine learning problems, the incorporation of [...]
Sea-level stability over geologic time owing to limited deep subduction of hydrated mantle
Published: 2021-01-06
Subjects: Earth Sciences
The presence of liquid water makes our planet unique. Its budget over geological timescales, i.e., the long-term global sea level, depends on the balance of water exchanges between the Earth's mantle and the surface through both volcanism (mantle degassing) and subduction of hydrous minerals (mantle regassing). Current estimates of subduction water fluxes predict that regassing exceeds degassing [...]
LakeEnsemblR: An R package that facilitates ensemble modelling of lakes
Published: 2021-01-06
Subjects: Fresh Water Studies, Hydrology, Numerical Analysis and Scientific Computing, Water Resource Management
Model ensembles have several benefits compared to single-model applications but are not frequently used within the lake modelling community. Setting up and running multiple lake models can be challenging and time consuming, despite the many similarities between the existing models (forcing data, hypsograph, etc.). Here we present an R package, LakeEnsemblR, that facilitates running ensembles of [...]
Determination of vulnerability areas from the simulated deposition of atmospheric pollutants using LOTOS-EUROS chemical transport model in North-West South-America
Published: 2021-01-06
Subjects: Applied Mathematics, Bioresource and Agricultural Engineering, Civil and Environmental Engineering, Computer Sciences, Engineering, Physical Sciences and Mathematics, Planetary Sciences
This work presents the implementation of the LOTOS-EUROS regional atmospheric Chemical Transport Model (CTM) on Northwestern South America. The impact of land use and orography update in the model was analyzed to identify potential vulnerable natural areas by quantifying atmospheric deposition pollutants. CTMs allow simulating the physical dynamics of trace gasses and aerosols, including [...]
Structural controls on the emplacement and evacuation of magma from a sub-volcanic laccolith; Reyðarártindur Laccolith, SE Iceland
Published: 2021-01-06
Subjects: Earth Sciences, Geology, Higher Education, Physical Sciences and Mathematics, Science and Mathematics Education, Tectonics and Structure, Volcanology
Comments on “On the reported magnetic precursor of the 1989 Loma Prieta earthquake” by J.N. Thomas, J.J. Love, and M.J.S. Johnston
Published: 2021-01-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Thomas et al. (2009) (hereafter TLJ09) attempt to cast doubt upon the report by FraserSmith et al. (1990) (hereafter FS90) of unusual large-amplitude ultra-low frequency (ULF; f < 10 Hz) magnetic fields preceding the M ~7 Loma Prieta earthquake. TLJ09 suggest there are instrumental problems with FS90’s data that we, the designers, builders and long-term operators of the equipment, are presumed to [...]
2-D P-SV and SH spectral element modelling of seismic wave propagation in non-linear media with pore-pressure effects
Published: 2021-01-06
Subjects: Earth Sciences, Engineering, Geophysics and Seismology, Geotechnical Engineering
It has long been recognized that the effects of superficial geological layers, or site effects, can play a major role on the seismic ground motion at the free surface. In this study, we compute wave propagation in a 2-D asymmetrical basin considering both soil non-linearity and pore- pressure effects. Equations of elastodynamics of wave propagation are solved using the spectral element method [...]
Spectral element modelling of seismic wave propagation in visco-elastoplastic media including excess-pore pressure development
Published: 2021-01-06
Subjects: Earth Sciences, Engineering, Geophysics and Seismology, Geotechnical Engineering
Numerical modelling of seismic wave propagation, considering soil nonlinearity, has become a major topic in seismic hazard studies when strong shaking is involved under particular soil conditions. Indeed, when strong ground motion propagates in saturated soils, pore pressure is another important parameter to take into account when successive phases of contractive and dilatant soil behaviour are [...]
Evaluation of the Grillo sensor, a low-cost accelerometer for IoT-based Real-time seismology
Published: 2021-01-02
Subjects: Geophysics and Seismology
Micro-Electro-Mechanical (MEMS) accelerometers are useful for real-time seismology due to their ability to record strong, unsaturated seismic signals. Recent advances in MEMS technologies enable design of instruments with improved capabilities that also allow recording of small signals. As a result, MEMS can be useful across a broad dynamic range and for both major earthquakes and smaller [...]
Joint event location and 3D Poisson’s ratio tomography for downhole microseismic monitoring
Published: 2021-01-02
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics
Passive seismic tomography plays a significant role in monitoring subsurface structures and properties during hydraulic fracturing. In this study, we develop a new passive seismic tomography approach to jointly invert for event locations, 3D P-wave velocity (Vp), and Poisson’s ratio models, for downhole microseimic monitoring The method enables to directly obtain the 3D Poisson’s ratio or Vp/Vs [...]
Global rates of soil production independent of soil depth
Published: 2021-01-02
Subjects: Physical Sciences and Mathematics
Accelerated rates of soil erosion threaten the stability of ecosystems1, nutrient cycles2, and global food supplies3 if the processes that produce soil cannot keep pace. Over millennial timescales, the rate of soil production is thought to keep pace with the rate of surface erosion through negative feedbacks between soil thickness and the rate at which soil is produced from the underlying mineral [...]
Identifying shale sweet spots by 3D microseismic imaging
Published: 2021-01-02
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics
Several studies suggest that shale sweet spots are likely associated with low Poisson’s ratio in the shale layer. Compared with conventional geophysical techniques with active seismic data, it is straightforward and cost effective to delineate the distribution of 3D Poisson’s ratio using microseismic data. In this study, we develop a method for determining microseismic event locations, 3D P-wave [...]
Vertical slowness constrained joint anisotropic parameters and event locations inversion for downhole microseismic monitoring
Published: 2020-12-31
Subjects: Physical Sciences and Mathematics
The construction of accurate anisotropic velocity models plays a very important role in microseismic monitoring of hydraulic fracturing. Due to ignorance of anisotropy, severe distortions may happen in the results of microseismic location and interpretation. While the methods are existing that invert for anisotropic parameters and event locations simultaneously with microseismic traveltime, the [...]
Automatic microseismic stacking location with a multi-cross-correlation imaging condition
Published: 2020-12-31
Subjects: Physical Sciences and Mathematics
Source scanning algorithm (SSA) has been recognized as a valid technique to automatically detect and locate passive seismic events. The imaging condition of this algorithm is the linear stack of the amplitudes along the traveltime curve from trial locations. However, the linear stacking condition may cause the location uncertainty due to the polarity reversal and low signal-to-noise ratio of the [...]
A study of nowcast of Indian Monsoon Rainfall over Mumbai using Rainymotion
Published: 2020-12-31
Subjects: Atmospheric Sciences, Meteorology, Numerical Analysis and Scientific Computing
Since ages, we know that rainfall is a very important factor in deciding the fate of a country. In an agrarian country like India where more than 70% of rural households are dependent on agriculture, agriculture contributes to nearly 17% GDP of the country and is directly dependent on rainfall. Excessive rainfall can lead to floods, landslides, soil erosion and no rainfall can lead to [...]