Preprints
There are 4718 Preprints listed.
Acoustic full waveform inversion for 2-D ambient noise source imaging
Published: 2022-12-20
Subjects: Physical Sciences and Mathematics
We present a method for estimating seismic ambient noise sources by acoustic full waveform inversion of interstation cross-correlations. The method is valid at local scales for laterally heterogeneous media, and ambient noise sources confined to the Earth's surface. Synthetic tests performed using an actual field array geometry, are used to illustrate three unique aspects of our work. First: the [...]
MA-SARNet: A one-shot nowcasting framework for SAR image prediction with physical driving forces
Published: 2022-12-19
Subjects: Civil and Environmental Engineering, Engineering
Remote sensing imagery is one of the most widely used data sources for large-scale Earth observations with consistent spatial and temporal quality. However, the current usage scenarios of Earth’s surface remote sensing images, such as those generated from Landsat, Sentinel 2, and SAR, are largely limited to retrospective tasks, as they are often used to reconstruct existing phenomena, such as [...]
Return of the Atacama deep Slow Slip Event : the 5-year recurrence confirmed by continuous GPS
Published: 2022-12-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Four years ago, using survey GPS measurements, the first deep slow slip event (SSE) was detected in Chile (near Copiapó, Atacama region), unrelated to any major earthquake. It was located between 40 and 60 km depth on the subduction interface, lasted approximately 18 months (2014-2016.5) and reached an equivalent magnitude of Mw~6.9. The single permanent station operating in the region between [...]
Using foreshocks to constrain earthquake nucleation: low foreshock to aftershock ratios in the Hikurangi subduction zone
Published: 2022-12-19
Subjects: Geophysics and Seismology
The complexity and duration of earthquake nucleation is an open question. Our understanding of this process is limited by a lack of high-quality observations of foreshocks and aftershocks. We therefore apply a coherence-based template matching approach to search for more foreshocks and aftershocks. We examine the half-hour before thousands of M3+ mainshocks on the Hikurangi subduction zone in New [...]
Trends in Planetary Science research in the Puna and Atacama desert regions: under-representation of local scientific institutions?
Published: 2022-12-19
Subjects: Planetary Sciences
In 2019 while launching a multidisciplinary research project aimed at developing the Puna de Atacama region as a natural laboratory, investigators within the University of Atacama (Chile) conducted a bibliographic search identifying previously studied geographical points of the region and of potential interest for planetary science and astrobiology research. This preliminary work highlighted a [...]
Role of fluid on earthquake occurrence: Example of the 2019 Ridgecrest and the 1997, 2009 and 2016 Central Apennines sequences
Published: 2022-12-19
Subjects: Earth Sciences
This paper focuses on the study of the temporal evolution of seismicity and the role of fluids during major earthquake sequences that occurred in the central Apennines and Southern Walker Lane belt-Eastern California Shear Zone over the last two decades: The 1997 Colfiorito sequence, the 2009 L’Aquila sequence, the 2016 Amatrice-Norcia sequence, and the 2019 Ridgecrest sequence. The availability [...]
Application of micro-CT to deep-marine outcrop data: towards a new tool to better assess primary sedimentary structures and processes at their origin
Published: 2022-12-17
Subjects: Numerical Analysis and Scientific Computing, Sedimentology
A new application of micro-CT on consolidated sediment-gravity flow deposits is presented with the objectives to characterize its internal sedimentary three-dimensional (3D) structures. The proposed concept is applied to three types of deep-marine sandstones, sampled in study areas showing different compositional properties: the Upper Cretaceous Gosau Group (Austria), the Eocene Hecho Group [...]
Synthesizing Sea Surface Temperature and Satellite Altimetry Observations Using Deep Learning Improves the Accuracy and Resolution of Gridded Sea Surface Height Anomalies
Published: 2022-12-17
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Gridded sea surface height (SSH) maps estimated from satellite altimetry are widely used for estimating surface ocean geostrophic currents. Satellite altimeters observe SSH along one-dimensional tracks widely spaced in space and time, making accurately reconstructing the two-dimensional (2D) SSH field challenging. Traditionally, SSH is mapped using optimal interpolation (OI). However, OI [...]
Evolution of the seasonal dynamics of the lake-terminating glacier Fjallsjökull, southeast Iceland, inferred using high-resolution repeat UAV imagery
Published: 2022-12-16
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Proglacial lakes are becoming ubiquitous at the termini of many glaciers worldwide, leading to increased glacier mass loss and terminus retreat, yet an understanding of the key processes forcing their behaviour is lacking. This study utilised high-resolution repeat uncrewed aerial vehicle (UAV)-Structure from Motion (SfM) imagery to provide insights into the changing dynamics of Fjallsjökull, a [...]
Wildfire influence on recent US pollution trends
Published: 2022-12-16
Subjects: Environmental Health and Protection, Environmental Monitoring, Environmental Public Health, Environmental Studies
Steady improvements in ambient air quality in the US over the past several decades have led to large public health benefits. However, recent trends in PM2.5 concentrations, a key pollutant, have stagnated or begun to reverse throughout much of the US. We quantify the contribution of wildfire smoke to these trends and find that since 2016, wildfire smoke has significantly slowed or reversed [...]
Linking thermal and rate behavior with fabric and mineralogy of clayey shear zones: Experimental investigation on the El Forn landslide (Andorra)
Published: 2022-12-16
Subjects: Civil and Environmental Engineering, Engineering, Geotechnical Engineering
Thermal triaxial tests were carried out on remolded material of core samples of the shear zone of a deep-seated landslide, the El Forn landslide (Andorra). With the thermal triaxial tests, we have obtained thermal and rate sensitivi- ties of the material outside and inside the shear band. Moreover, micro-scale tests were carried out, such as XRPD, SEM-EDS, MicroCT, and plasticity index. The [...]
Stinging News: ‘Dickinsonia’ discovered in the Upper Vindhyan of India Not Worth the Buzz
Published: 2022-12-16
Subjects: Earth Sciences, Physical Sciences and Mathematics
A recent report of Dickinsonia tenuis ‘hiding in plain sight’ at the Bhimbetka rock shelters in rocks of the Maihar sandstone (Upper Vindhyan) has important implications for paleogeography and the age of the Upper Vindhyan. We visited the site in December 2022 and found the evidence for Dickisonia lacking. The ‘fossil’ resembles decayed parts of modern Apis dorsata (giant honeybees) hives. In [...]
Re-examining Temporal Variations in Intermediate-Depth Seismicity
Published: 2022-12-16
Subjects: Geophysics and Seismology
Changes in the frequency of intermediate-depth (60–300 km) earthquakes in response to static stress transfer can provide insights into the mechanisms of earthquake generation within subducting slabs. In this study, we use the most up-to-date global and regional earthquake catalogues to show that both the aftershock productivity of large earthquakes, and the changes in the frequency of [...]
Oxidation Rates and Redox Stabilization of Ferrous Iron in Trioctahedral Smectites
Published: 2022-12-16
Subjects: Biogeochemistry, Geochemistry, Other Earth Sciences, Planetary Biogeochemistry, Planetary Geochemistry
Iron(II)-bearing trioctahedral smectites (saponites) form during anoxic alteration of basaltic rock. They are predicted to have been widespread on the early Earth and are observed in the oceanic subsurface today. Smectite structures, including the occupancy of sites in the octahedral sheet, affect iron redox behavior but the rates and products of trioctahedral smectite oxidation have been largely [...]
Historical & future maximum ocean temperatures
Published: 2022-12-16
Subjects: Oceanography
Marine heatwaves impact ocean ecosystems and are expected to become more frequent and intense with continued global warming. The ability of Earth system models to reproduce the statistical characteristics of extreme ocean temperatures has not yet been tested quantitatively, making the reliability of their future projections of marine heatwaves uncertain. We demonstrate that annual maxima of [...]