Preprints
Filtering by Subject: Earth Sciences
Remote bed-level change and overwash observation with low-cost ultrasonic distance sensors
Published: 2021-06-13
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Few datasets exist of high-frequency, in situ measurements of storm overwash, an essential mechanism for the subaerial maintenance of barrier islands and spits. Here we describe a new sensor platform for measuring bed-level change and estimating overwash inundation depths. Our MeOw (Measuring Overwash) stations consist of two ultrasonic distance sensors, a microprocessor board, and a camera and [...]
Ubiquity of human-induced changes in climate variability
Published: 2021-06-12
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
While climate change mitigation targets necessarily concern maximum mean state changes, understanding impacts and developing adaptation strategies will be largely contingent on how climate variability responds to increasing anthropogenic perturbations. Here we present a new 100-member large ensemble of climate change projections conducted with the Community Earth System Model version 2 to examine [...]
A Reduced Order Approach for Probabilistic Inversions of 3D Magnetotelluric Data II: Joint inversion of 3D MT and Surface-Wave Data
Published: 2021-06-10
Subjects: Earth Sciences, Geophysics and Seismology
Joint probabilistic inversions of magnetotelluric (MT) and seismic data has great potential for imaging the thermochemical structure of the lithosphere as well as mapping fluid/melt pathways and regions of mantle metasomatism. In this contribution we present a novel probabilistic (Bayesian) joint inversion scheme for 3D MT and surface-wave dispersion data particularly designed for large-scale [...]
Independent constraints on deep-sea temperatures across two early Eocene hyperthermals from clumped isotope thermometry
Published: 2021-06-08
Subjects: Earth Sciences, Geochemistry
The early Eocene hothouse experienced the occurrence of transient global warming events, so-called hyperthermals. The deep ocean constitutes a stable and vast heat reservoir, and hence arguably provides a good estimate of the global mean climate state. However, available proxy deep-sea temperature reconstructions rely on uncertain assumptions of non-thermal influences associated with seawater [...]
The hazards of unconfined pyroclastic density currents: a new synthesis and classification according to their deposits, dynamics, and thermal and impact characteristics
Published: 2021-06-08
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Pyroclastic density currents (PDCs) that escape their confining channels are among the most dangerous of volcanic hazards. These unconfined PDCs are capable of inundating inhabited areas that may be unprepared for these hazards, resulting in significant loss of life and damage to infrastructure. Despite their ability to cause serious impacts, unconfined PDCs have previously only been described [...]
Spatial and morphometric relationships of submarine landslides offshore west and southwest Iberia
Published: 2021-06-08
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy
Submarine landslides are ubiquitous geohazards in marine environments occurring at multiple scales. Increasing efforts have been made to catalogue and categorise submarine landslides in comprehensive databases, aiming to better understand their preconditioning and trigger factors. Using the recently compiled, open-access MAGICLAND dataset, we investigate the distribution and morphometric trends [...]
The effect of temperature-dependent material properties on simple thermal models of subduction zones
Published: 2021-06-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
To a large extent, the thermal structure of a subduction zone determines where seismicity occurs through the transition from brittle to ductile deformation and the depth of dehydration reactions. Thermal models of subduction zones can help understand this seismicity by accurate modelling of the thermal structure of the subduction zone. Here, we assess a common simplification in thermal models of [...]
Tectonic Studies Group Equality Diversity and Inclusion report 2021
Published: 2021-05-28
Subjects: Earth Sciences, Geology, Tectonics and Structure
In 2021, the TSG Annual Meeting was held online due to the coronavirus pandemic. To build on our 2019 gender diversity report, we wanted to begin gathering diversity data proactively and anonymously. This will enable us to be more inclusive of marginalised genders, avoid mis-gendering participants and to collect a wider range of diversity data. We ran a survey of the presenters and session chairs [...]
Novel sensor array helps to understand submarine cable faults off West Africa
Published: 2021-05-28
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Seabed telecommunication cables can be damaged or broken by powerful seafloor flows of sediment (called turbidity currents), which may runout for hundreds of kilometres into the deep ocean. These flows have the potential to affect multiple cables near-simultaneously over very large areas, so it is more challenging to reroute traffic or repair the cables. However, cable-breaking turbidity currents [...]
Deep-water syn-rift stratigraphy as archives of Early-Mid Pleistocene palaeoenvironmental signals and controls on sediment delivery
Published: 2021-05-27
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy
The timing and character of coarse siliciclastic sediment delivered to deep-water environments in active rift basins is governed by the complicated interactions of tectonics, climate, eustasy, hinterland geology, and shelf process regime. The stratigraphic archives of deep-water syn-rift basin-fills provide records of palaeoenvironmental changes (e.g. climate and vegetation) in onshore [...]
Quantifying the influence of conduit inclination on Taylor Bubble behaviour in basaltic magmas.
Published: 2021-05-27
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
The ascent of single Taylor bubbles suspended in a range of Newtonian liquids, scaled to mimic basaltic magmas, within vertical and inclined tubes has been studied experimentally over the range 0° to 70° (where 0° is vertical and 90° is horizontal). Using measurements of Taylor bubble parameters (ascent velocity and film thickness) and morphology, alongside dimensionless numbers, we show that [...]
Quantifying the impact of lagged hydrological responses on the effectiveness of groundwater conservation
Published: 2021-05-27
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Many irrigated agricultural areas seek to prolong the lifetime of their groundwater resources by reducing pumping. However, it is unclear how lagged responses, such as reduced groundwater recharge caused by more efficient irrigation, may impact the long-term effectiveness of conservation initiatives. Here, we use a variably saturated, simplified surrogate groundwater model to: 1) analyze aquifer [...]
High-resolution petrographic evidence confirming detrital and biogenic magnetites as remanence carriers for Zongpu carbonates in the Gamba area, South Tibet
Published: 2021-05-26
Subjects: Earth Sciences
Paleocene carbonates from the Gamba area of South Tibet provide the largest paleomagnetic dataset for constraining the paleogeography of the India-Asia collision in the early stage. The characteristic remanences (ChRMs) obtained from this unit were, however, argued for a chemical remagnetization via orogenic fluids. This study carries out a high-resolution petrographic study on the Paleocene [...]
Meteorites that produce K-feldspar-rich ejecta blankets correspond to mass extinctions.
Published: 2021-05-24
Subjects: Applied Statistics, Atmospheric Sciences, Earth Sciences, Geology, Other Planetary Sciences, Paleontology, Physical Sciences and Mathematics
Meteorite impacts load the atmosphere with dust and cover the Earth‘s surface with debris. They have long been debated as a trigger of mass extinctions through Earth‘s history. Impact winters generally last <100 years, whereas ejecta blankets persist for 10^3-10^5 years. Here we show that only meteorite impacts that emplaced ejecta blankets rich in K-feldspar (Kfs) correlate to Earth system [...]
What sets aeolian dune height?
Published: 2021-05-23
Subjects: Climate, Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Earth's major sand seas are often populated with giant dunes, up to hundreds of meters in height and kilometers in wavelength. These massive sediment piles, visible from space on our planet and across the Solar System, indicate that conditions for sand transport have persisted for millenia. Unraveling how giant dunes form therefore has implications for understanding atmospheric flows and climatic [...]