Preprints
There are 5541 Preprints listed.
The Sidi Ifni transect across the rifted margin of Morocco (Central Atlantic): Vertical movements constrained by low-temperature thermochronology
Published: 2021-03-17
Subjects: Earth Sciences, Geology, Geomorphology, Paleontology, Sedimentology, Stratigraphy, Tectonics and Structure
The occurrence of km-scale exhumations during syn- and post-rift stages has been documented along Atlantic continental margins, which are also characterised by basins undergoing substantial subsidence. The relationship between the exhuming and subsiding domains is poorly understood. In this study, we reconstruct the evolution of a 50 km long transect across the Moroccan rifted margin from the [...]
Prototyping a collaborative data curation service for coastal science
Published: 2021-03-16
Subjects: Environmental Sciences, Geomorphology, Physical Sciences and Mathematics
The growing push for open data has resulted in an abundance of data for coastal researchers, which can lead to problems for individual researchers related to discoverability of relevant data. One solution is to explicitly develop services for coastal researchers to help curate data for discovery, hosting discussions around reuse, community building, and finding collaborators. To develop the idea [...]
Pre-salt rift morphology controls salt tectonics in the Campos Basin, offshore SE Brazil
Published: 2021-03-14
Subjects: Physical Sciences and Mathematics
Classic models of gravity-driven salt tectonics commonly depict kinematically-linked zones of overburden deformation, characterised by updip extension and downdip contraction, separated by a weakly deformed zone associated with downdip translation above a relatively smooth base-salt surface. We use 2D and 3D seismic reflection and borehole data from the south-central Campos Basin to show that [...]
Lithologic Controls on Silicate Weathering Regimes of Temperate Planets
Published: 2021-03-12
Subjects: Astrophysics and Astronomy, Earth Sciences, Geochemistry, Planetary Geochemistry, Planetary Sciences
Weathering of silicate rocks at a planetary surface can draw down CO2 from the atmosphere for eventual burial and long-term storage in the planetary interior. This process is thought to provide essential negative feedback to the carbonate-silicate cycle (carbon cycle) to maintain clement climates on Earth and potentially similar temperate exoplanets. We implement thermodynamics to determine [...]
High resolution, annual maps of field boundaries for smallholder-dominated croplands at national scales
Published: 2021-03-12
Subjects: Agriculture, Environmental Monitoring, Environmental Sciences, Geographic Information Sciences, Geography, Life Sciences, Natural Resources and Conservation, Physical and Environmental Geography, Physical Sciences and Mathematics, Remote Sensing, Spatial Science, Sustainability
Mapping the characteristics of Africa's smallholder-dominated croplands, including the sizes and numbers of fields, can provide critical insights into food security and a range of other socioeconomic and environmental concerns. However, accurately mapping these systems is difficult because there is 1) a spatial and temporal mismatch between satellite sensors and smallholder fields, and 2) a lack [...]
Large-scale natural fracture network patterns: Insights from automated mapping in the Lilstock (Bristol Channel) limestone outcrops
Published: 2021-03-12
Subjects: Earth Sciences
The Lilstock outcrop in the southern Bristol Channel provides exceptional outcrop of several limestone layers with stratabound fracture networks, providing the opportunity to create a very large, complete, and ground-truthed fracture model. Here we present the result of automated fracture extraction of high-resolution photogrammetric images (0.9 cm/pixel) of the full outcrop, obtained using an [...]
Phosphorus supply affects long-term carbon accumulation in mid-latitude ombrotrophic peatlands
Published: 2021-03-12
Subjects: Earth Sciences, Environmental Sciences
Ombrotrophic peatlands are a globally important carbon store and depend on atmospheric nutrient deposition to balance ecosystem productivity and microbial decomposition. Human activities have increased atmospheric nutrient fluxes, but the impacts of variability in phosphorus supply on carbon sequestration in ombrotrophic peatlands are unclear. Here, we synthesise phosphorus, nitrogen and carbon [...]
The Ca and Mg isotope record of the Cryogenian Trezona carbon isotope excursion
Published: 2021-03-11
Subjects: Earth Sciences, Geochemistry, Geology, Sedimentology, Stratigraphy
The Trezona carbon isotope excursion is recorded on five different continents in platform carbonates deposited prior to the end-Cryogenian Marinoan glaciation (>635 Ma) and represents a change in carbon isotope values of 16-18 per mill. Based on the spatial and temporal reproducibility, the excursion previously has been interpreted as tracking the carbon isotopic composition of dissolved [...]
The imprint of erosion by glacial lake outburst floods in the topography of central Himalayan rivers
Published: 2021-03-11
Subjects: Earth Sciences, Geomorphology
In steep landscapes, river incision sets the pace of landscape evolution. Transport of coarse sediment controls incision by evacuating material delivered to river channels by landslides. However, large landslide-derived boulders that impede bedrock erosion are immobile even in major runoff-driven floods. Glacial lake outburst floods (GLOFs) mobilize these boulders and drive incision, yet their [...]
Local and global controls on carbon isotope chemostratigraphy
Published: 2021-03-11
Subjects: Earth Sciences
Over million-year timescales, the geologic cycling of carbon controls long-term climate and the oxidation of Earth's surface. Inferences about the carbon cycle can be made from time series of carbon isotopic ratios measured from sedimentary rocks. The foundational assumption for carbon isotope chemostratigraphy is that carbon isotope values reflect dissolved inorganic carbon in a well-mixed ocean [...]
Rise and fall of vegetation primary production resilience to climate variability anticipated by a large ensemble of Earth System Models’ simulations
Published: 2021-03-09
Subjects: Life Sciences
Climate change is affecting many aspects of natural ecosystems and society. Anticipating the changes in vegetation resilience – the plants’ capacity to cope with disturbances and shocks such as those related to climate variability and extremes – is critical to understand and project ecosystems’ responses to global change and the impacts on the related ecosystem services, to support mitigation [...]
Magma pathways in sill-complexes
Published: 2021-03-09
Subjects: Physical Sciences and Mathematics
The Loch Scridain Sill-complex on the Isle of Mull affords an opportunity to examine how magma moves through and builds sill-complexes (Holness & Humphreys 2003). For example, field and petrological evidence indicates the Tràigh Bhàn na Sgùrra Sill is segmented and comprised several thick channels, separated by thin sill portions, that facilitated longer-lived magma flow (Holness & Humphreys [...]
Segment tip geometry of sheet intrusions, I: Theory and numerical models for the role of tip shape in controlling propagation pathways.
Published: 2021-03-09
Subjects: Physical Sciences and Mathematics
Inferences about sheet intrusion emplacement mechanisms have been built largely on field observations of intrusion tip zones: magmatic systems that did not grow beyond their observed state. Here we use finite element simulation of elliptical to superelliptical crack tips, representing observed natural sill segments, to show the effect of sill tip shape in controlling local stress concentrations, [...]
Climate change risks to push one-third of global food production outside Safe Climatic Space
Published: 2021-03-09
Subjects: Agriculture, Earth Sciences, Environmental Sciences
Climate change will alter key climatic conditions which human societies directly rely on and which, for example, food production is adjusted to. Here, using Holdridge Life Zones, we define Safe Climatic Space (SCS), a concept that incorporates the decisive climatic characteristics of precipitation, temperature and aridity. This allows us first to define the climatic niche of current food [...]
Decadal shoreline erosion and recovery of beaches in modified and natural estuaries
Published: 2021-03-08
Subjects: Geomorphology, Physical Sciences and Mathematics
Sandy beaches in estuaries and bays (BEBs) are common landforms on the coasts of many major cities. They exist under a wide range of settings and their morphology is controlled by their distance from the estuary/bay entrance, exposure to different types of waves (e.g., ocean swells vs locally generated wind waves), proximity to flood-tide delta/shoals, and anthropogenic interventions (e.g., [...]