Preprints
There are 4725 Preprints listed.
Coherent streamflow variability in Monsoon Asia over the past eight centuries---links to oceanic drivers
Published: 2019-11-13
Subjects: Climate, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Monsoon Asia region is home to ten of the world’s biggest rivers, supporting the lives of 1.7 billion people who rely on streamflow for water, energy, and food. Yet, a synoptic understanding of multi-centennial streamflow variability for this region is lacking. Here we produce the first large scale streamflow reconstruction over Monsoon Asia (63 stations in 16 countries), using a novel [...]
Logarithmic growth of dikes from a depressurizing magma chamber
Published: 2019-11-13
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Dike propagation is an intrinsically multiphase problem, where deformation and fluid flow are intricately coupled in a fracture process. Here we perform the first fully-coupled simulations of dike propagation in two dimensions, accounting for depressurization of a circular magma chamber, dynamic fluid flow, fracture formation, and elastic deformation. Despite the complexity of the governing [...]
Directionality of ambient noise in the Mississippi embayment
Published: 2019-11-12
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Cross-correlations of ambient seismic noise from 277 broadband stations within the Mississippi embayment (ME) with at least 1-month of recording time between 1990 and 2018 are used to estimate source locations of primary and secondary microseisms. We investigate source locations by analyzing the azimuthal distribution of the signal-to- noise ratio (SNR) and positive/negative amplitude [...]
Three-scale multiphysics finite element framework (FE3) modelling fault reactivation
Published: 2019-11-11
Subjects: Chemical Engineering, Computational Engineering, Engineering, Petroleum Engineering
Fluid injection or production in petroleum reservoirs affects the reservoir stresses such that it can even sometime reactivate dormant faults in the vicinity. In the particular case of deep car- bonate reservoirs, faults can also be chemically active; chemical dissolution of the fault core can transform an otherwise impermeable barrier to a flow channel. Due to the scale separation of the fault [...]
Low-cost electronic sensors for environmental research: pitfalls and opportunities
Published: 2019-11-08
Subjects: Earth Sciences, Environmental Sciences, Geography, Physical Sciences and Mathematics, Social and Behavioral Sciences
Repeat observations underpin our understanding of environmental processes but financial constraints often limit scientists’ ability to deploy dense networks of conventional commercial instrumentation. Rapid growth in the Internet-Of-Things (IOT) and the maker movement is paving the way for low-cost electronic sensors to transform global environmental monitoring. Accessible and inexpensive sensor [...]
Ancient subducted oceans controlling the positioning of deep mantle plumes
Published: 2019-11-08
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Seismic imaging of the Earths interior reveals plumes originating from relatively hot regions of the lower mantle, surrounded by cooler material thought to be remnants of ancient subducted oceans. Based largely on geophysical data, two opposing hypotheses dominate the discussion on dynamics at the base of mantle: the large hot anomalies are thermo-chemical in nature; or, alternatively, they are [...]
Logjams are not jammed: measurements of log motions in Big Creek, Idaho
Published: 2019-11-07
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Colloquially, a "logjam" indicates a kinematic arrest of movement. Taken literally, it refers to a type of dense accumulation of wood in rivers widely recognized as bestowing numerous biological and physical benefits to the system but also present serious hazards to infrastructure. Despite this, no in-situ field measurements have assessed the degree of arrest in a naturally-formed logjam. Using [...]
A note on the instability and pattern formation of shrinkage cracks in viscoplastic soils
Published: 2019-11-07
Subjects: Civil and Environmental Engineering, Engineering, Materials Science and Engineering
In this note we present a theoretical study on the conditions for the onset of cracks, as well as the corresponding pattern formation, in saturated viscoplastic soils under isotropic loading (extension). The type of stress applied is left unspecified, to cover a variety of loadings including shrinkage due to dessication, isotropic thermal expansion, mechanical loading and so forth. By treating [...]
Pore network model predictions of Darcy-scale multiphase flow heterogeneity validated by experiments
Published: 2019-11-07
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Small-scale heterogeneities in multiphase flow properties fundamentally control the flow of fluids from very small to very large scales in geologic systems. Inability to characterize these heterogeneities often limits numerical model descriptions and predictions of multiphase flow across scales. In this study, we evaluate the ability of pore network models (PNM) to characterize multiphase flow [...]
Growth, overprinting, and stabilization of Proterozoic Provinces in the southern Lake Superior region
Published: 2019-11-07
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Tectonics and Structure
New geochronologic data in the southern Lake Superior region provide key information on the timing and nature of tectonic activity that pre-and post-date initial Paleoproterozoic growth of Laurentia during the geon 18 Penokean orogeny. The obducted Pembine ophiolite formed along the edge of a Paleoproterozoic ocean basin at least 30 m.y. prior to Penokean island arc/microcontinent accretion [...]
Nowcasting submarine slope instability at local, margin, and global scales using machine learning
Published: 2019-11-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Submarine slope instability (SSI) is a broad term for events ranging from 100 km3 instantaneous open slope failures on continental margins to 0.001 km3 creeping mudflows on heavily sedimented river deltas. SSI events such as the 2018 Sunda Strait and 1929 Grand Banks submarine landslides extract high societal tolls, yet SSI predictive capability is limited. SSI observational studies are resource [...]
Chemical versus mechanical denudation in meta-clastic and carbonate bedrock catchments on Crete, Greece, and mechanisms for steep and high carbonate topography
Published: 2019-11-05
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
On Crete — as is common elsewhere in the Mediterranean — carbonate massifs form high mountain ranges whereas topography is lower in areas with meta-clastic rocks. This observation suggests that differences in denudational processes between carbonate-rich rocks and quartzofeldspathic units impart a fundamental control on landscape evolution. Here we present new cosmogenic basin-average denudation [...]
On the statistical significance of foreshock sequences in Southern California
Published: 2019-11-05
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Earthquake foreshocks may provide information that is critical to short-term earthquake forecasting. However, foreshocks are far from ubiquitously observed, which makes the interpretation of ongoing seismic sequences problematic. Based on a statistical analysis, Trugman & Ross (2019) suggested that as much as 72% of all mainshocks in Southern California is preceded by foreshock sequences. In [...]
Equifinality, Sloppiness, and emergent model structures of mechanistic soil biogeochemical models
Published: 2019-11-05
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics, Soil Science
Biogeochemical models increasingly consider the microbial control of car- bon cycling in soil. The major current challenge is to validate mechanistic descriptions of microbial processes and predicted system responses against experimental observations. We analyzed soil biochemical models of different complexity regarding parameter identifiability using information geometry, i.e. a model is [...]
The global lake area, climate, and population dataset
Published: 2019-11-05
Subjects: Environmental Monitoring, Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
An increasing population in conjunction with a changing climate necessitates a detailed understanding of water abundance at multiple spatial and temporal scales. Remote sensing has provided massive data volumes to track fluctuations in water quantity, yet contextualizing water abundance with other local, regional, and global trends remains challenging by often requiring large computational [...]