Preprints
Filtering by Subject: Earth Sciences
Thermal forcing expected to modulate convection in a mechanically forced stationary wave
Published: 2022-08-16
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Physical Sciences and Mathematics
This is a reply to the comment by Lofverstrom and Thirumalai on our publication in Nature. That comment and this reply underwent peer review at Nature, and Nature declined to publish the exchange
Geomorphological indicators
Published: 2022-08-09
Subjects: Earth Sciences
Several physical, chemical, and biological processes shape coastal environments close to sea level. Acting through time, these processes create a variety of coastal landforms. When found outside their environment of formation, these landforms can be used by geoscientists as geomorphological indicators of former relative sea levels. In this chapter, we outline the main processes acting on coastal [...]
Double surface rupture and hydraulic recharge of a three-fault system during the Mw 4.9 earthquake of 11 November 2019 at Le Teil (France)
Published: 2022-08-08
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Numerical Analysis and Scientific Computing
The Mw 4.9 earthquake of 11 November 2019 at Le Teil (France) occurred at a very shallow depth (about 1 km) inducing the surface rupture of La Rouvière fault, nearby of a limestone quarry. Thanks to satellite differential interferometry, we detected the existence of the secondary surface rupture of the quasi-parallel Bayne Rocherenard fault. A newly processed seismic cross-section allowed us to [...]
Estimating the Occurrence of Slow Slip Events and Earthquakes with an Ensemble Kalman Filter
Published: 2022-08-07
Subjects: Applied Mathematics, Earth Sciences, Physical Sciences and Mathematics
Our ability to forecast earthquakes and slow slip events is hampered by limited information on the current state of stress on faults. Ensemble data assimilation methods permit estimating the state by combining physics-based models and observations, while considering their uncertainties. We employ an Ensemble Kalman Filter (EnKF) to estimate shear stresses, slip rates, and the state theta acting [...]
A High-order Accurate Summation-by-Parts Finite Difference Method for Fully-dynamic Earthquake Sequence Simulations within Sedimentary Basins
Published: 2022-08-06
Subjects: Applied Mathematics, Earth Sciences, Physical Sciences and Mathematics
We present a computationally efficient numerical method for earthquake sequences that incorporates wave propagation during rupture. A vertical strike-slip fault governed by rate-and-state friction is embedded in a heterogeneous elastic half-space discretized using a high-order accurate Summation-by-Parts finite difference method. We develop a two solver approach: Adaptive time-stepping is [...]
Within the subducting Nazca Plate: The 2020 Mw 6.8 Calama earthquake and its similarity with the surrounding inslab seismicity
Published: 2022-08-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We study the 2020 MW 6.8 Calama earthquake sequence that occurred within the subducting oceanic Nazca plate. The mainshock is modeled via waveform inversion using a dynamic rupture model, while detection and location techniques are used to better characterize its aftershock sequence. We analyze the local seismotectonic and thermal context of the subducting Nazca plate to understand the trigger [...]
Atlantic Water intrusion triggers rapid retreat and regime change at previously stable Greenland glacier
Published: 2022-08-04
Subjects: Earth Sciences, Glaciology
Ice discharge from Greenland’s marine-terminating glaciers contributes to half of all mass loss from the ice sheet, with numerous mechanisms proposed to explain their retreat. Here, we examine K.I.V Steenstrups Nordre Bræ (‘Steenstrup’) in Southeast Greenland, which, between 2018—2021, retreated ~7 km, thinned ~20%, doubled in discharge, and quadrupled in flow speed. This rate of acceleration is [...]
Testing the potential of using coarse-grain feldspars for post-IR IRSL dating of calcium sulphate-wedge growth in the Atacama Desert
Published: 2022-08-04
Subjects: Earth Sciences
The growth of vertically laminated calcium-sulphate wedges in the Atacama Desert is assumed to be driven by the interaction of moisture supply and salt dynamics in the subsurface. Geochronological data of these wedge laminations is yet sparse but indispensable to resolve wedge-growth phases and episodes of moisture supply and to use these deposits as a palaeoclimate archive in the hyperarid [...]
Influence of reef isostasy, dynamic topography, and glacial isostatic adjustment on sea-level records in Northeastern Australia
Published: 2022-08-04
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics
Understanding sea level during the warmest peak of the Last Interglacial (125,000 yrs ago; Marine Isotope Stage 5e) is important for assessing future ice-sheet dynamics in response to climate change, and relies on the measurement and interpretation of paleo sea-level indicators, corrected for post-depositional vertical land motions. The coasts and continental shelves of northeastern Australia [...]
Resolving minute temporal seismic velocity changes induced by earthquake damage: The more stations, the merrier ?
Published: 2022-07-29
Subjects: Earth Sciences, Geophysics and Seismology
Ground shaking induced by earthquakes often introduces transient changes in seismic velocity monitored with ambient noise. These changes are usually attributed to relaxation behavior following the co-seismic damage in the subsurface and are of relevance for postseismic hazard mitigation. However, the velocity evolution associated with this phenomenon can occur at very small timescales and [...]
Mud redeposition during river incision as a factor affecting authigenic 10Be/9Be dating: Early Pleistocene large mammal fossil-bearing site Nová Vieska, eastern Danube Basin
Published: 2022-07-29
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy
This study examines the suitability of the authigenic 10Be/9Be dating method to the dating of the deposits of an incising river, taking as an example the Nová Vieska river terrace, which accumulated during the neotectonic inversion of the Danube Basin (western Slovakia). The succession was formed by a wandering river with minor preservation of proximal floodplain muds. The frequent occurrence of [...]
Water discharge variations control fluvial stratigraphic architecture in the Middle Eocene Escanilla formation, Spain
Published: 2022-07-27
Subjects: Earth Sciences, Geology, Geomorphology, Hydrology, Sedimentology, Stratigraphy
Ancient fluvial deposits typically display repetitive changes in their depositional architecture such as alternating intervals of coarse-grained highly amalgamated (HA), laterally-stacked, channel bodies, and finer-grained less amalgamated (LA), vertically-stacked, channels encased in floodplain deposits. Such patterns are usually ascribed to slower, respectively higher, rates of base level rise [...]
Sampling across large-scale geological gradients to study geosphere-biosphere interactions
Published: 2022-07-25
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Geochemistry, Life Sciences, Microbiology
Despite being one of the largest microbial ecosystems on Earth, with >1029 microbial cells, many basic open questions remain about how life exists and thrives in the deep subsurface biosphere, inside Earth’s crust. Much of this ambiguity is due to the fact that it is exceedingly difficult and (often prohibitively expensive) to directly sample the deep subsurface, requiring elaborate drilling [...]
Geochemical implication of Eu isotopic ratio in anorthosite: new evidence of Eu isotope fractionation during feldspar crystallization
Published: 2022-07-25
Subjects: Earth Sciences, Physical Sciences and Mathematics
Rare earth element geochemistry can provide critical information on the evolution of the crust-mantle system. Europium (Eu) exists in divalent and trivalent states, and Eu2+ can substitute for Ca2+ during plagioclase feldspar crystallization in reducing magmas. This leads to positive Eu anomaly in Ca-plagioclase-rich anorthosite derived from the mantle and negative Eu anomalies in fractionated [...]
Machine Learning for Elastic-Electrical Cross-Property Modelling Of Sandstones
Published: 2022-07-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics