Preprints
Filtering by Subject: Earth Sciences
Seismic interferometry in the presence of an isolated noise source
Published: 2022-07-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Seismic interferometry gives rise to a correlation wavefield that is closely related to the Green's function under the condition of uniformly distributed noise sources. In the presence of an additional isolated noise source, a second contribution to this wavefield is introduced that emerges from the isolated source location at negative lapse time. These two contributions interfere, which may bias [...]
The root to the Galápagos mantle plume on the core-mantle boundary
Published: 2022-07-01
Subjects: Earth Sciences, Physical Sciences and Mathematics
Ultra-low velocity zones (ULVZs) are thin anomalous patches on the boundary between the Earth's core and mantle, revealed by their effects on the seismic waves that propagate through them. Here we map a broad ULVZ near the Galápagos hotspot using shear-diffracted waves. Forward modelling assuming a cylindrical shape shows the patch is ~600 km wide, ~20 km high, and its shear velocities are ~25% [...]
Developing seagrass index for long term monitoring of Zostera japonica seagrass bed: a case study in Yellow River Delta, China
Published: 2022-06-30
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Geographic Information Sciences, Geography, Physical and Environmental Geography, Remote Sensing
Seagrass beds offer unique and vital ecological services as an important blue carbon ecosystem in coastal wetlands. Zostera japonica is an intertidal seagrass species native to eastern Asia and is one of the most widely distributed seagrass species in China. However, little is known on the long-term variations of Z. japonica extents. Automatic mapping method for Z. japonica seagrass beds is in [...]
Towards Robust River Plastic Detection: Combining Lab and Field-based Hyperspectral Imagery
Published: 2022-06-29
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Hydrology, Statistical Models
Plastic pollution in aquatic ecosystems has increased dramatically in the last five decades, with strong impacts on human and aquatic life. Recent studies endorse the need for innovative approaches to monitor the presence, abundance, and types of plastic in these ecosystems. One approach gaining rapid traction is the use of multi- and hyperspectral cameras. However, most experiments using this [...]
Advecting Superspecies: Efficiently Modeling Transport of Organic Aerosol with a Mass-Conserving Dimensionality Reduction Method
Published: 2022-06-26
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Engineering, Environmental Chemistry, Environmental Engineering, Environmental Sciences, Other Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The chemical transport model LOTOS-EUROS uses a volatility basis set (VBS) approach to represent the formation of secondary organic aerosol (SOA) in the atmosphere. Inclusion of the VBS approximately doubles the dimensionality of LOTOS-EUROS and slows computation of the advection operator by a factor of two. This complexity limits SOA representation in operational forecasts. We develop a [...]
Controls on grain size distribution in an ancient sand sea
Published: 2022-06-25
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology
Grain size distribution in deserts is driven by a combination of autogenic controls such as grain abrasion and sorting due to wind transport and allogenic controls such as provenance and spatial changes in wind-direction. Downwind grain-size trends in present day sand seas display contrasting results. For example, the Namib and Hexi Corridor sand seas show broad downwind fining and sorting [...]
Building Archean cratonic roots
Published: 2022-06-17
Subjects: Earth Sciences
Geophysical, geochemical, and geological investigations have attributed the stable behaviour of Earth's continents to the presence of their Archean cratonic roots. These roots are likely composed of melt-depleted, low density residual peridotite with high Magnesium number (Mg#), while devolatilisation from the upper mantle during magmatic events might have made these roots more viscous and [...]
Validation of glacial-interglacial rainfall variations in southwest Sulawesi using Mg/Ca and δ18O in speleothems
Published: 2022-06-17
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Geochemistry, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Speleology
The final version of this article is now published with Communications. Earth and Environment. To view this open access article, please use the Published Article DOI. Speleothem δ18O is widely used as a proxy for rainfall amount in the tropics on glacial-interglacial to interannual scales. However, uncertainties in the interpretation of this renowned proxy pose a vexing problem in tropical [...]
High resolution assessment of coal mining methane emissions by satellite in Shanxi, China
Published: 2022-06-17
Subjects: Earth Sciences, Environmental Sciences
Accurate assessment of coal mine methane (CMM) emissions is a prerequisite for defining baselines and assessing the effectiveness of mitigation measures. Such an endeavor is jeopardized however by large uncertainties in current CMM estimates. Here, we assimilated images of methane column atmospheric mixing ratios observed by the TROPOMI space borne instrument in a high-resolution regional [...]
Clay Mineral Type and Content Control Properties of Fine-Grained CO2 Caprocks—Laboratory Insights from Strongly Swelling and Non-Swelling Clay–Quartz Mixtures
Published: 2022-06-17
Subjects: Earth Sciences
Understanding and predicting sealing characteristics and containment efficiency as a function of burial depth across sedimentary basins is a prerequisite for safe and secure subsurface storage. Instead of estimators and empirical relationships, this study aimed to delineate data-driven variability domains for non-cemented fine-grained clastic caprocks. Constant rate-of-strain uniaxial compression [...]
Understanding Sampling Bias in the Global Heat Flow Compilation
Published: 2022-06-17
Subjects: Databases and Information Systems, Earth Sciences, Geology, Tectonics and Structure
Geothermal heat flow is commonly inferred from the gradient of temperature values in boreholes. Such measurements are expensive and logistically challenging in remote locations and, therefore, often targeted to regions of economic interest. As a result, measurements are not distributed evenly. Some tectonic, geologic and even topographic settings are overrepresented in global heat flow [...]
Advances in seismic imaging of magma and crystal mush
Published: 2022-06-17
Subjects: Earth Sciences, Geophysics and Seismology, Volcanology
Seismic imaging methods have provided detailed three-dimensional constraints on the physical properties of magmatic systems leading to invaluable insight into the storage, differentiation and dynamics of magma. These constraints have been crucial to the development of our modern understanding of magmatic systems. However, there are still outstanding knowledge gaps resulting from the challenges [...]
The Mechanisms of Tsunami Amplification and the Earthquake Source of the 2021 M7 Acapulco, Mexico, Earthquake
Published: 2022-06-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
Here we show a slip model for the 2021 M7 Acapulco, Mexico, earthquake produced by inversion of strong motion, GNSS, tide gauge, and InSAR data. The earthquake occurs within the Guerrero gap, identified as a region of concern for its seismogenic potential and paucity of large events. We find that rupture was compact, constrained to depths between 10 and 20 km and consistent of two main slip [...]
Space-time landslide hazard modeling via Ensemble Neural Networks
Published: 2022-06-02
Subjects: Applied Statistics, Artificial Intelligence and Robotics, Computer Sciences, Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Statistics and Probability
For decades, a full numerical description of the spatio-temporal dynamics of a landslide could be achieved only via physics-based models. The part of the geomorphology community focusing on data-driven model has instead focused on predicting where landslides may occur via susceptibility models. Moreover, they have estimated when landslides may occur via models that belong to the [...]
Foraminifera as a tool for the reconstruction of paleobathymetry and geohazard: A case study from Taiwan
Published: 2022-06-02
Subjects: Earth Sciences
The calcite tests of foraminifera are an important biogenic component of marine sediments. The abundance of foraminiferal tests in marine sediments broadly varies with bathymetry, thus has been used to reconstruct paleobathymetry. It is also promising as a tracer for downslope transport triggered by earthquakes and typhoons, especially if the displaced material from shallow locality contrasts [...]