There are 2102 Preprints listed.
Published: 2021-04-06
Subjects: Physical Sciences and Mathematics
This article presents a novel data-driven approach for studying long-term temporal rainfall pattern over the central highlands of West Papua, Indonesia. Using wavelet transforms we found indications of negative temporal relationship of El Niño - Southern Oscillation (ENSO) and 12-month Standarized Precipitation Index (SPI-12). Based on this causal relationship, we perform dynamic causality [...]
Published: 2021-04-06
Subjects: Environmental Monitoring, Geophysics and Seismology, Tectonics and Structure
A number of recent modeling studies of induced seismicity have used the rate-and-state friction model of Dieterich (1994) to account for the fact that earthquake nucleation is not instantaneous. Notably, the model assumes a population of seismic sources accelerating towards instability with a distribution of intial slip speeds such that they would produce earthquakes steadily in absence of any [...]
Published: 2021-04-06
Subjects: Applied Mathematics, Geophysics and Seismology, Tectonics and Structure
Faults in the crust at seismogenic depths are embedded in a fluid-saturated, elastic, porous material. Slip on such faults may induce transient pore pressure changes through dilatancy or compaction of the gouge or host rock. However, the poroelastic nature of the crust and the full coupling of inelastic gouge processes and the host rock have been largely neglected in previous analyses. Here, we [...]
Published: 2021-04-02
Subjects: Earth Sciences
Over the last decade, there has been a resurgence of interest in the climatic and tectonic mechanisms that drove the Messinian salinity crisis (MSC) and the associated deposition of thick evaporites. The MSC represents an unprecedented palaeoceanographic change that led to a very short (c. 660 kyr) ecological and environmental crisis. However, across the Levantine offshore basin, the [...]
Published: 2021-04-02
Subjects: Biogeochemistry, Earth Sciences, Geomorphology
Coastal salt marshes are productive environments with high potential for carbon accumulation and storage. Even though organic carbon in salt marsh sediment is typically attributed to plant biomass, it can also be produced by benthic photosynthetic biofilms. These biofilms, generally composed of diatoms and their secretions, are known for their high primary productivity and contribution to the [...]
Published: 2021-04-02
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
The Clean Water Act (CWA) is the primary federal mechanism by which the physical, chemical, and biological integrity of streams, lakes, and wetlands are protected in the U.S. The CWA has evolved considerably since its initial passage in 1948, including explicit expansions and contractions of jurisdictional scope through a series of legislative actions, court decisions, and agency rules. Here, we [...]
Published: 2021-03-31
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Climate changes across the last 24,000 years provide key insights into Earth system responses to external forcing. Climate model simulations and proxy data have independently allowed for study of this crucial interval; however, they have at times yielded disparate conclusions. Here, we leverage both types of information using paleoclimate data assimilation to produce the first observationally [...]
Published: 2021-03-31
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics
The San Andreas Fault (SAF) is one of the dominant components of the transform boundary between the Pacific and the North American Plate. Although the fault is verti-cal-to sub-vertical at shallow (<10 km) depth, it variably dips at angles of ca. 40-70º to the southwest near the western Transverse Range and to the northeast in its southern seg-ment at depths of ca. 10-20 km, and thus can be [...]
Published: 2021-03-30
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Ancient and recent terrestrial carbonate-precipitating systems are characterised by a heterogeneous array of deposits volumetrically dominated by calcite. In these environments, calcite precipitates display an extraordinary morphological diversity, from single crystal rhombohedral prisms, to blocky crystalline encrustations, or spherulitic to dendritic aggregates. Despite many decades of thorough [...]
Published: 2021-03-30
Subjects: Oceanography and Atmospheric Sciences and Meteorology
The 94-GHz airborne HIAPER Cloud Radar (HCR) has now been deployed in three major field campaigns. NCAR has developed an extensive set of quality assurance and quality control procedures which are applied to all collected data. Engineering measurements performed both in the laboratory and in an antenna measurement chamber yielded calibration characteristics for the antenna, reflector, and radome. [...]
Published: 2021-03-29
Subjects: Geology
Outcrop studies of fracture networks are important to understand fractured reservoirs in the subsurface, but complete maps of all fractures in large outcrops are rare due to limitations of outcrop and image resolution. We manually mapped the first full-resolution UAV-based, Gigapixel dataset and DEM of the wave-cut Lilstock Benches in the southern Bristol Channel basin, a classic outcrop of [...]
Published: 2021-03-26
Subjects: Physical Sciences and Mathematics
The Northern Hemisphere stratospheric polar vortex (SPV), a band of fast westerly winds over the pole extending from approximately 10 to 50 km altitude, is a key driver of European winter weather. Extremely weak polar vortex states, so called sudden stratospheric warmings (SSW), are on average followed by dry and cold weather in Northern Europe, as well as wetter and warmer conditions in Southern [...]
Published: 2021-03-26
Subjects: Physical Sciences and Mathematics
The fast flow of glaciers and ice sheets is largely influenced by friction at the ice- bedrock interface, and our imperfect understanding of subglacial friction accounts for one of the largest uncertainties in predictions of future sea-level rise. Glacier motion ranges from slow creep to cyclic surge instabilities and devastating glacier collapse as well as continuously fast-flowing ice-streams. [...]
Published: 2021-03-26
Subjects: Geology, Sedimentology, Stratigraphy
Sea straits are elongate basin geometries that are common in the sedimentary record and play a key role in oceanography and climate. Due to the intricate confluence of marine processes and the typically complex structural settings of sea straits, many sedimentary and stratigraphic characteristics of these depositional systems are not fully understood. To better resolve these, we study excellent [...]
Published: 2021-03-25
Subjects: Physical Sciences and Mathematics, Planetary Sciences
Titan, the largest moon of Saturn, is characterized by gigantic linear dunes and an active dust cycle. Much like on Earth, these and other aeolian processes are caused by the wind-driven mobilization of surface grains, known as saltation. To date, very little is known about the conditions that allow for the occurrence of saltation on Titan. In fact, Titan saltation may be fundamentally different [...]