Preprints
Filtering by Subject: Geology
Crisis at the Salton Sea: The Vital Role of Science
Published: 2021-03-04
Subjects: Atmospheric Sciences, Biogeochemistry, Chemistry, Climate, Earth Sciences, Environmental Chemistry, Environmental Public Health, Environmental Sciences, Environmental Studies, Geochemistry, Geology, Geomorphology, Hydrology, Medicine and Health Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Public Health, Social and Behavioral Sciences
The Salton Sea—a hypersaline, terminal lake in southern California—is in crisis. A combination of mismanagement and competition among federal, state and local agencies has hindered efforts to address declining lake levels and unstable water chemistry. This delay has heightened the public health threat to regional communities as retreating shorelines expose dry lakebed— a source of potentially [...]
An uncertainty-focused database approach to extract spatiotemporal trends from qualitative and discontinuous lake-status histories
Published: 2021-03-01
Subjects: Climate, Earth Sciences, Geology, Geomorphology, Hydrology, Longitudinal Data Analysis and Time Series, Other Earth Sciences, Sedimentology, Statistical Methodology, Stratigraphy
Changes in lake status are often interpreted as palaeoclimate indicators due to their dependence on precipitation and evaporation. The Global Lake Status Database (GLSDB) has since long provided a standardised synopsis of qualitative lake status over the last 30,000 14C years. Potential sources of uncertainty however are not recorded in the GLSDB. Here we present an updated and improved [...]
INCORPORATING INFORMATION ON VARYING SEDIMENTATION RATES INTO PALEONTOLOGICAL ANALYSES
Published: 2021-02-26
Subjects: Earth Sciences, Geology, Paleobiology, Paleontology, Sedimentology, Stratigraphy
Stratigraphic changes in the clustering of first or last taxon occurrences are a joint expression of evolutionary, ecological, taphonomic, and sedimentological processes. Sedimentation rates control the degree of sedimentary dilution and condensation and thus alter the time contained in a given thickness of sediment. However, it remains poorly explored quantitatively how distinct the [...]
Shallow or deep? A reinterpretation of the Rifian Corridor’s unique sandy contourites
Published: 2021-02-25
Subjects: Climate, Earth Sciences, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Paleontology, Sedimentology, Stratigraphy
This study proposes that sandstone layers exposed in the Fez-Meknes region of Northern Morocco (Ben Allou (Sidi Chaded) and El Adergha localities), have been misinterpreted as unique examples of geostrophically-driven, deep marine (150 - 400 m water depth) sandy contourites. Instead, our independent paleontological, sedimentological, and stratigraphic analyses show that these sandstones represent [...]
Evidence for crustal removal, tectonic erosion and flare-ups from the Japanese evolving forearc sediment provenance
Published: 2021-02-24
Subjects: Earth Sciences, Geochemistry, Geology, Tectonics and Structure
Forearc basins preserve the geologic record relating strictly to arc magmatism. The provenance of forearc sediment can be used to differentiate periods of crustal growth, accretion, and destruction, enhanced magmatism, advancing and retreating subduction slabs, delamination, etc. All these tectonic events systems predict differing degrees of sedimentary reworking of the older forearc units. [...]
A record of plume-induced plate rotation triggering seafloor spreading and subduction initiation
Published: 2021-02-23
Subjects: Earth Sciences, Geology, Tectonics and Structure
The formation of a global network of plate boundaries surrounding a mosaic of lithospheric fragments was a key step in the emergence of Earth’s plate tectonics. So far, propositions for plate boundary formation are regional in nature but how plate boundaries are being created over 1000s of km in short periods of geological time remains elusive. Here, we show from geological observations that a [...]
A database of submarine landslides offshore West and Southwest Iberia
Published: 2021-02-22
Subjects: Earth Sciences, Geology
Submarine landslides are major geohazards occurring on distinct seabed domains ranging from shallow coastal areas to the deeper points of the ocean. The nature and relief of the seabed are key factors influencing the location and size of submarine landslides. Efforts have recently been made to compile databases of submarine landslide distribution and morphometry, a crucial task to assess [...]
The True Cost of Field Education is a Barrier to Diversifying Geosciences
Published: 2021-02-19
Subjects: Earth Sciences, Education, Environmental Sciences, Geology, Higher Education, Outdoor Education, Science and Mathematics Education
Fieldwork is considered critical to developing technical skills in geoscience education, and typical undergraduate degrees require >30 days in the field. Tuition costs of enrolling in field camp are acknowledged as a barrier to participation in geosciences; however, the cost of participation in field activities may also include the cost of personal field gear (hiking boots, backpacks, etc.), [...]
The surface deformation of the 2020 Doğanyol-Sivrice earthquake (Mw 6.8) and the earlier events suggest Mw˂7.0 earthquakes do not create significant surface slip along the East Anatolian Fault Zone
Published: 2021-02-18
Subjects: Geology, Geophysics and Seismology, Tectonics and Structure
The 2020 Mw 6.8 Doğanyol-Sivrice earthquake occurred on the Pütürge Segment of the left-lateral East Anatolian Fault Zone (EAFZ). Our field investigation within 6 weeks after the earthquake suggests the following results. (1) The 2020 earthquake created a ~54-km-long surface deformation zone along the Pütürge Segment. (2) No co-seismic surface slip has been formed after the earthquake. (3) The [...]
Structural and stratigraphic development of Offshore NW Sulawesi, Indonesia
Published: 2021-02-14
Subjects: Earth Sciences, Geology, Geomorphology, Sedimentology, Stratigraphy, Tectonics and Structure
The area of the Offshore NW Sulawesi lies between eastern Sundaland (Borneo) and the North Arm of Sulawesi. Possible influences on the basins include Paleogene rifting in the Celebes Sea and Makassar Strait, Neogene subsidence and uplift in Borneo, late Neogene subduction at the present-day North Sulawesi Trench, and displacements related to the Palu-Koro Fault. This study presents the results of [...]
Numerical modeling of Earth's dynamic surface: a community approach
Published: 2021-02-14
Subjects: Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Geology, Geomorphology, Glaciology, Hydrology, Numerical Analysis and Scientific Computing, Other Environmental Sciences, Physical Sciences and Mathematics, Sedimentology, Soil Science, Stratigraphy
Computational modelling occupies a unique niche in Earth environmental sciences. Models serve not just as scientific technology and infrastructure, but also as digital containers of the scientific community's understanding of the natural world. As this understanding improves, so too must the associated software. This dual nature---models as both infrastructure and hypotheses---means that [...]
234U/230Th coral growth dating yields reliable ages in restricted basins despite anomalous δ234Ui values
Published: 2021-02-10
Subjects: Geochemistry, Geology, Tectonics and Structure
Late Quaternary coral growth ages from uplifted coastal regions, such as marine terraces and associated palaeoshorelines, are an essential tool used to derive tectonic and fault controlled uplift and deformation rates, and thus contribute to seismic hazard analysis and constrain past global sea levels. Fossil coral growth ages are assessed for reliability based upon whether the δ234Ui (or [...]
Classification, segmentation and correlation of zoned minerals
Published: 2021-02-01
Subjects: Earth Sciences, Environmental Sciences, Geochemistry, Geology, Numerical Analysis and Scientific Computing, Statistics and Probability, Volcanology
Minerals exhibit zoning patterns that can be related to changes in the environment in which they grew. Using statistical methods that have been designed to segment optical images, we have developed a procedure to segment zonation within minerals and correlate these zones between multiple crystals using elemental maps. This allows us to quantify the complexity and variability of chemical zoning [...]
Ordination analysis in sedimentology, geochemistry and paleoenvironment - background, current trends and recommendations
Published: 2021-02-01
Subjects: Biogeochemistry, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Multivariate Analysis, Oil, Gas, and Energy, Other Earth Sciences, Paleobiology, Paleontology, Sedimentology
Ordination is the name given to a group of methods used to analyze multiple variables without preceding hypotheses. Over the last few decades the use of these methods in Earth science in general, and notably in analyses of sedimentary sources, has dramatically increased. However, with limited resources oriented towards Earth scientists on the topic, the application of ordination analysis is at [...]
Quantitative chemical mapping of plagioclase as a tool for the interpretation of volcanic stratigraphy: an example from Saint Kitts, Lesser Antilles
Published: 2021-02-01
Subjects: Earth Sciences, Geochemistry, Geology, Stratigraphy, Volcanology
Establishing a quantitative link between magmatic processes occurring at depth and volcanic eruption dynamics is essential to forecast the future behaviour of volcanoes, and to correctly interpret monitoring signals at active centres. Chemical zoning in minerals, which captures successive events or states within a magmatic system, can be exploited for such a purpose. However, to develop a [...]