Preprints
There are 6976 Preprints listed.
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 [...]
Thermal stratification and meromixis in four dilute temperate zone lakes
Published: 2022-12-14
Subjects: Life Sciences, Physical Sciences and Mathematics
Four adjacent lakes (Arco, Budd, Deming, and Josephine) within Itasca State Park in Minnesota, USA are reported to be meromictic in the scientific literature. However, seasonally persistent chemoclines have never been documented. We collected seasonal profiles of temperature and specific conductance and placed temperature sensor chains in two lakes for ~ 1 year to explore whether these lakes [...]
A treatise on InSAR geometry and 3D displacement estimation
Published: 2022-12-14
Subjects: Engineering, Physical Sciences and Mathematics
The estimation of displacement vectors for (objects on) the Earth’s surface using satellite InSAR requires geometric transformations of the observables based on orbital viewing geometries. Usually, there are insufficient viewing geometries available for full 3D reconstruction, leading to non-unique solutions. Currently, there is no standardized approach to deal with this problem, resulting in [...]
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
Tracing timing of growth in cultured mollusks using strontium spiking
Published: 2022-12-23
Subjects: Aquaculture and Fisheries Life Sciences, Biogeochemistry, Geochemistry, Paleontology
Growth experiments present a powerful tool for determining the effect of environmental parameters on growth and carbonate composition in biogenic calcifiers. For successful proxy calibration and biomineralization studies, it is vital to exactly identify volumes of carbonate precipitated at precise intervals during the experiment. Here, we investigate the use of strontium labelling in mollusk [...]