Preprints
Filtering by Subject: Earth Sciences
Turbidites, Topography and Tectonics: Evolution of submarine channel-lobe systems in the salt-influenced Kwanza Basin, offshore Angola
Published: 2020-04-07
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology
Understanding the evolution of submarine channel-lobe systems on salt-influenced slopes is challenging as systems react to seemingly subtle changes in sea-floor topography. The impact of large blocking structures on individual deep-water systems is well documented, but understanding of the spatio-temporal evolution of regionally extensive channel-lobe systems in areas containing modest salt [...]
Seismic electric signals (SES) and earthquakes: A review of an updated VAN method and competing hypotheses for SES generation and earthquake triggering
Published: 2020-04-07
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Studies, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Sciences, Social and Behavioral Sciences
Electromagnetic phenomena are sometimes associated with seismic events, but earthquake prediction using seismic electric signals (SES) has not been seriously considered since the early 1990s. There are several causes: (1) false alarms that have created panics in Greece, and (2) a strong critique of the Varotsos-Alexopoulos-Nomicos (VAN) method used there. An updated VAN method that includes time [...]
Is the Aftershock Zone Area a Good Proxy for the Mainshock Rupture Area?
Published: 2020-04-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The locations of aftershocks are often observed to be on the same fault plane as the mainshock and used as proxies for its rupture area. Recent developments in earthquake relocation techniques have led to great improvements in the accuracy of earthquake locations, offering an unprecedented opportunity to quantify both the aftershock distribution and mainshock rupture area. In this study, we [...]
Measuring Azimuth Deformation With L-Band ALOS-2 ScanSAR Interferometry
Published: 2020-04-06
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Computational Engineering, Computer Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Hydrology, Mining Engineering, Other Earth Sciences, Physical Sciences and Mathematics, Signal Processing, Tectonics and Structure, Volcanology
We analyze the methods for measuring azimuth deformation with the L-band Advanced Land Observing Satellite-2 (ALOS-2) scanning synthetic aperture radar (ScanSAR) interferometry. To implement the methods, we extract focused bursts from the ALOS-2 full-aperture product, which is the only product available for ScanSAR interferometry at present. The extracted bursts are properly processed to measure [...]
Estimating Azimuth Offset With Double-Difference Interferometric Phase: The Effect of Azimuth FM Rate Error in Focusing
Published: 2020-04-06
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Environmental Sciences, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Hydrology, Mining Engineering, Other Earth Sciences, Physical Sciences and Mathematics, Physics, Tectonics and Structure, Volcanology
Estimating azimuth offset with double-difference interferometric (DDI) phase, which is called multiple-aperture interferometric synthetic aperture radar (InSAR) or spectral diversity, is increasingly used in recent years to measure azimuth deformation or to accurately coregister a pair of InSAR images. We analyze the effect of frequency modulation (FM) rate error in focusing on the DDI phase with [...]
Rethinking Groundwater Age
Published: 2020-04-03
Subjects: Earth Sciences, Geochemistry, Hydrology, Physical Sciences and Mathematics
The ideas that old or “fossil” groundwater cannot be pumped sustainably, or that recently recharged groundwater is inherently sustainable are both mistaken. Both old and young groundwaters can be used in physically sustainable or unsustainable ways.
Climate controls the length and shape of the world’s drainage basins
Published: 2020-04-01
Subjects: Earth Sciences, Geomorphology, Hydrology, Physical Sciences and Mathematics
Submitted manuscript currently under review at Geophysical Research Letters (American Geophysical Union publication).
Global Sensitivity Analysis to Optimize Basin-Scale Conductive Model Calibration – A Case Study From the Upper Rhine Graben
Published: 2020-04-01
Subjects: Applied Mathematics, Earth Sciences, Physical Sciences and Mathematics
Calibrating geothermal simulations is a critical step, both in scientific and industrial contexts, with suitable model parameterizations being optimised to reduce discrepancies between simulated and measured temperatures. Here we present a methodology to identify unaccounted physical processes in the process and overcome the problem of measurement sparsity. With an application to the Upper Rhine [...]
Ultraviolet camera measurements of passive and explosive sulphur dioxide emissions at Yasur volcano, Vanuatu
Published: 2020-03-31
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Here, we present the first ultraviolet (UV) camera measurements of sulphur dioxide (SO2) flux from Yasur volcano, Vanuatu, for the period 6th – 9th July 2018. These data yield the first direct gas measurement-derived calculations of explosion gas masses at Yasur. Yasur typically exhibits persistent passive gas release interspersed with frequent strombolian explosions. We used compact forms of the [...]
Continuum of earthquake rupture speeds enabled by oblique slip
Published: 2020-03-31
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquake rupture speed can affect ground shaking and thus seismic hazard. Seismological observations show that large earthquakes span a continuum of rupture speeds, from slower than Rayleigh waves up to P wave speed, and include speeds that are predicted to be unstable by 2D theory. This discrepancy between observations and theory has not yet been reconciled by a quantitative model. Here we [...]
International disparities in open access practices of the Earth Sciences community
Published: 2020-03-31
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Hydrology, Library and Information Science, Mineral Physics, Other Earth Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Social and Behavioral Sciences, Soil Science, Speleology, Stratigraphy, Tectonics and Structure, Volcanology
Short communication on international disparities in open access practices of the Earth Sciences community
The mechanism of Mg diffusion in forsterite and the controls on its anisotropy
Published: 2020-03-31
Subjects: Earth Sciences, Mineral Physics, Physical Sciences and Mathematics
Mg diffusion is important for explaining many rheological properties in forsterite but its mechanism is unknown. Without knowing a mechanism the effect of variables such as pressure are hard to constrain. In this study we used Density Functional Theory (DFT) to calculate the diffusivity of Mg vacancies and interstitials in forsterite and thus the diffusion rate of Mg in forsterite. We predict [...]
A New Synergistic Approach for Monitoring Wetlands Using 1 Sentinels -1 and 2 data With Object-based Machine Learning 2 Algorithms
Published: 2020-03-30
Subjects: Earth Sciences, Life Sciences, Other Earth Sciences, Physical Sciences and Mathematics
In this work the synergistic use of Sentinel-1 and 2 combined with the System for Automated Geoscientific Analyses (SAGA) Wetness Index in the content of land use/cover (LULC) mapping with emphasis in wetlands is evaluated. A further objectivehas been to a new Object-based Image Analysis (OBIA) approach for mapping wetland areas using Sentinel-1 and 2 data, where the latter is also tested [...]
Shallow-water mudstone architecture and depositional process variability: evidence for heterogeneity at kilometre-scale
Published: 2020-03-30
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Mudstone studies that use a large spacing (>5km) between datapoints provide little insight into the architecture and depositional process variability at kilometre scale. This often leads to the assumption that mudstones are laterally homogenous at kilometre and sub-kilometre scales. To better understand the lateral variability of mudstones at kilometre scale, the Mancos Shale in the eastern [...]
RainDisaggGAN - Temporal Disaggregation of Spatial Rainfall Fields with Generative Adversarial Networks
Published: 2020-03-30
Subjects: Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Hydrology, Physical Sciences and Mathematics
Creating spatially coherent rainfall patterns with high temporal resolution from data with lower temporal resolution is an important topic in many geoscientific applications. From a statistical perspective, this presents a high-dimensional and highly under-determined problem. However, recent advances in unsupervised machine learning provide methods for learning such high-dimensional probability [...]