Preprints
Filtering by Subject: Physical Sciences and Mathematics
Higher Long-Term Soil Moisture Increases Organic Carbon Accrual Through Microbial Conversion of Organic Inputs
Published: 2021-09-08
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
High long-term soil moisture may either stimulate or inhibit soil organic carbon (SOC) losses through changes to mineral and chemical composition, and resultant organo-mineral interactions. Yet, the trade-off between mineralization and accrual of SOC under long-term variation in unsaturated soil moisture remains an uncertainty. In this study, we tested the underexplored relationships between [...]
Interannual variability in methane and nitrous oxide concentrations and sea-air fluxes across the North American Arctic Ocean (2015–2019)
Published: 2021-09-07
Subjects: Physical Sciences and Mathematics
Between 2015–2018, we collected approximately 2000 water column measurements of methane (CH4) and nitrous oxide (N2O) concentrations in the North American Arctic Ocean during summer and early fall. We also obtained 25 measurements of CH4 and N2O concentrations in rivers along the Northwest Passage and Ellesmere Island in mid-summer 2017–2019. Our results show that N2O is generated in the highly [...]
Lowermost mantle shear-velocity structure from hierarchical trans-dimensional Bayesian tomography
Published: 2021-09-05
Subjects: Earth Sciences, Physical Sciences and Mathematics
The core-mantle boundary (CMB) is the most extreme boundary within the Earth where the liquid, iron-rich outer core interacts with the rocky, silicate mantle. The nature of the lowermost mantle atop the CMB, and its role in mantle dynamics, is not completely understood. Various regional studies have documented significant heterogeneities at different spatial scales. While there is a consensus on [...]
Recharge observations indicate strengthened groundwater connection to surface fluxes
Published: 2021-09-03
Subjects: Physical Sciences and Mathematics
Groundwater is an invaluable global resource, but its long-term viability as a resource for consumption, agriculture, and ecosystems depends on precipitation recharging aquifers. How much precipitation recharges groundwaters varies enormously across Earth's surface, but recharge rates are uncertain because field observations are sparse and modeled global estimates remain largely unvalidated. Here [...]
CCREM: New reference Earth model from the global coda-correlation wavefield
Published: 2021-09-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
The existing Earth reference models have provided an excellent one-dimensional representation of Earth’s properties as a function of its radius and explained many seismic observations in a broad frequency band. However, some discrepancies still exist among these models near the first-order discontinuities (e.g., the core-mantle and the inner-core boundaries) due to different datasets and [...]
An overview of multimethod imaging approaches in environmental geophysics
Published: 2021-08-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Quantitative characterization of subsurface properties is critical for many environmental applications and serves as the basis to simulate and better understand dynamic subsurface processes. Geophysical imaging methods allow to image subsurface property distributions and monitor their spatio-temporal changes in a minimally invasive manner. While it is widely agreed upon that models integrating [...]
Pedogenic processes and the drying of Mars
Published: 2021-08-30
Subjects: Physical Sciences and Mathematics
What exactly caused Mars to lose its liquid water billions of years ago remains as one of the most enduring questions in planetary science. New insights from Mars suggest that crustal hydration – the formation of hydrated minerals during aqueous alteration of the crust – contributed to the long-term drying of the planet. Here, we advance the hypothesis that hydration of the Martian crust could [...]
No demonstrated link between sea-level and eruption history at Santorini
Published: 2021-08-24
Subjects: Physical Sciences and Mathematics
Previous studies have suggested a link between rates of sea-level variation and eruptions globally [McGuire et al., 1997], with Satow and coauthors [2021] presenting the first detailed comparison between sea-level change and eruptive history for a single island-volcano. They use robust, high-resolution ages for volcanic deposits at Santorini, combined with a 2D numerical model to correlate [...]
Parsimonious velocity inversion applied to the Los Angeles Basin, CA
Published: 2021-08-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The proliferation of dense arrays promises to improve our ability to image geological structures at the scales necessary for accurate assessment of seismic hazard. However, combining the resulting local high-resolution tomography with existing regional models presents an ongoing challenge. We developed a framework based on the level-set method that infers where local data provide meaningful [...]
SUBSTRATE ENTRAINMENT, DEPOSITIONAL RELIEF, AND SEDIMENT CAPTURE: IMPACT OF A SUBMARINE LANDSLIDE ON FLOW PROCESS AND SEDIMENT SUPPLY
Published: 2021-08-23
Subjects: Physical Sciences and Mathematics
Submarine landslides can generate complicated patterns of seafloor relief that influence subsequent flow behaviour and sediment dispersal patterns. While the large-scale morphology of submarine landslide deposits, or mass transport deposits (MTDs), can be resolved in seismic data, the nature of their upper surface, and its impact on facies distributions and stratal architecture of overlying [...]
Comprehensive aerial survey quantifies high methane emissions from the New Mexico Permian Basin
Published: 2021-08-20
Subjects: Atmospheric Sciences, Engineering, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Physical Sciences and Mathematics
Limiting emissions of climate-warming methane from oil and gas (O&G) is a major opportunity for short-term climate benefits. We deploy a basin-wide airborne survey of the New Mexico Permian Basin, spanning 35,923 km^2, 26,292 active wells, and over 15,000 km of natural gas pipelines using an independently-validated hyperspectral methane point source detection and quantification system. The [...]
The Optimal Correlation Detector?
Published: 2021-08-19
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Correlation detectors are now used routinely in seismology to detect occurrences of signals bearing close resemblance to a reference waveform. They facilitate the detection of low-amplitude signals in significant background noise that may elude detection using energy detectors, and they associate a detected signal with a source location. Many seismologists use the fully normalized correlation [...]
Safety and Belonging in the Field: A Checklist for Educators
Published: 2021-08-19
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Cosmochemistry, Earth Sciences, Education, Environmental Education, Environmental Health and Protection, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Environmental Studies, Fresh Water Studies, Geochemistry, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Higher Education, Human Geography, Hydrology, Life Sciences, Meteorology, Mineral Physics, Natural Resource Economics, Natural Resources and Conservation, Natural Resources Management and Policy, Nature and Society Relations, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Other Earth Sciences, Other Environmental Sciences, Other Geography, Other Oceanography and Atmospheric Sciences and Meteorology, Other Planetary Sciences, Outdoor Education, Paleobiology, Paleontology, Physical and Environmental Geography, Physical Sciences and Mathematics, Planetary Biogeochemistry, Planetary Geochemistry, Planetary Geology, Planetary Geomorphology, Planetary Geophysics and Seismology, Planetary Glaciology, Planetary Hydrology, Planetary Mineral Physics, Planetary Sciences, Planetary Sedimentology, Remote Sensing, Sedimentology, Social and Behavioral Sciences, Soil Science, Spatial Science, Speleology, Stratigraphy, Sustainability, Tectonics and Structure, Volcanology, Water Resource Management
Ensuring taught fieldwork is a positive, generative, collective, and valuable experience for all participants requires considerations beyond course content. To guarantee safety and belonging, participants’ identities (backgrounds and protected characteristics) must be considered as a part of fieldwork planning and implementation. Furthermore, getting fieldwork right is an important step in [...]
Seasonality in Arctic Warming Driven By Sea Ice Effective Heat Capacity
Published: 2021-08-17
Subjects: Physical Sciences and Mathematics
Arctic surface warming under greenhouse gas forcing peaks in early winter and reaches its minimum during summer in both observations and model projections. Many mechanisms have been proposed to explain this seasonal asymmetry, but disentangling these processes remains a challenge in the interpretation of general circulation model (GCM) experiments. To isolate these mechanisms, we use an idealized [...]
Does ENSO significantly affect rice production in Indonesia? A preliminary study using computational time-series approach
Published: 2021-08-15
Subjects: Climate, Environmental Sciences, Physical Sciences and Mathematics
ENSO is a phenomenon that is suspected to influence rice production in Indonesia. In this study, we try to find a direct correlation between ENSO and rice production in this region by using various latest computational time series methods, such as Dynamic Time Warping, Wavelet Coherence, and Bayesian Structural Time Series to quantify the statistical relationship between the Multivariate ENSO [...]