Preprints
There are 5427 Preprints listed.
Widespread Wood Placement and Regrading Drive Lateral Connectivity and Reworking of the Channel and Floodplain in a Valley Bottom Reset to Stage 0
Published: 2023-03-31
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Valley bottom process reset, or the excavation of high surfaces and fill of incised channels combined with large wood addition, is a new method for creating multi-channel river-wetland corridors (also referred to as Stage 0 valley bottoms). Valley bottom process reset seeks to increase lateral flow and sediment connectivity to retain flow and sediment and kickstart geomorphic processes that may [...]
A novel fluoro-electrochemical technique for classifying diverse marine nanophytoplankton
Published: 2023-03-31
Subjects: Life Sciences, Physical Sciences and Mathematics
To broaden our understanding of pelagic ecosystem responses to environmental change, it is essential that we improve the spatio-temporal resolution of in situ monitoring of phytoplankton communities. A key challenge for existing methods is in classifying and quantifying cells within the nanophytoplankton size range (2-20µm). This is particularly difficult when there are similarities in [...]
Reconciling fast and slow cooling during planetary formation as recorded in the main group pallasites
Published: 2023-03-31
Subjects: Cosmochemistry, Other Planetary Sciences, Physical Sciences and Mathematics, Planetary Geology, Planetary Sciences
Pallasite meteorites contain evidence for vastly different cooling timescales: rapid cooling at high temperatures (K/yrs) and slow cooling at lower temperatures (K/Myrs). Pallasite olivine also shows contrasting textures ranging from well-rounded to angular and fragmental, and some samples record chemical zoning. Previous pallasite formation models have required fortuitous changes to the parent [...]
A shallow approximation for ice streams sliding over strong beds
Published: 2023-03-29
Subjects: Glaciology, Partial Differential Equations
Ice streams are regions of rapid ice sheet flow characterised by a high degree of sliding over a deforming bed. The Shallow Shelf Approximation (SSA) provides a convenient way to obtain closed-form approximations of the velocity and flux in a rapidly-sliding ice stream when the basal drag is much less than the driving stress. However, the validity of the SSA approximation breaks down when the [...]
Stationary surface waves and antidunes in dense pyroclastic density currents
Published: 2023-03-28
Subjects: Earth Sciences, Sedimentology, Volcanology
Stationary antidunes are a product of critical flow in open channel systems, but with poor preservation potential. They are related to the existence of stationary surface waves in the overriding current, but their existence in the dense pyroclastic density current regime has been unrecognized to date. Experiments presented here demonstrate that surface waves in simulated dense pyroclastic density [...]
Bayesian estimation of nonlinear centroid moment tensors using multiple seismic data sets
Published: 2023-03-27
Subjects: Earth Sciences, Geophysics and Seismology
Centroid moment tensor (CMT) parameters of earthquakes are routinely estimated to gain information on structures and regional tectonics. However, for small earthquakes (M<4), it is still challenging to determine CMTs due to the lack of high-quality waveform data. In this study, we propose to improve solutions for small earthquakes by incorporating multiple seismic data types in Bayesian joint [...]
Linking the core heat content to Earth's accretion history
Published: 2023-03-26
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Planetary Geochemistry, Planetary Geophysics and Seismology
In this study we use a parameterized model of differentiation in a magma ocean setting, in which the magma ocean depth evolves during accretion, to predict the composition of the primordial core. We couple this chemical model to a thermal evolution model of the accreting metal to estimate the Earth's core heat content at the end of its formation. We find geochemically consistent models. All these [...]
N-S versus E-W extension in the Tibetan plateau: Are they driven by the same dynamics?
Published: 2023-03-25
Subjects: Earth Sciences, Physical Sciences and Mathematics
The tectonic history of the Himalaya-Tibet Mountain Range records two important extensional tectonic events: 1) N-S extension in the Himalaya-Tibet transition zone, and 2) E-W extension in the southern and central Tibet, manifested in the form of east-west and north-south striking normal faults, respectively. The N-S extensional event (~22 Ma) started to commence earlier than the E-W extension [...]
Crop Yield Prediction based on Reanalysis and Crop Phenology Data in the Agroclimatic Zones
Published: 2023-03-24
Subjects: Agriculture, Civil and Environmental Engineering, Environmental Engineering
Crop yield and phenological stages are remarkably sensitive to not only environmental factors like atmospheric conditions and physical properties of soils but also agricultural activities. Accurate crop yield prediction plays a crucial role in food security and agricultural sustainability. There are several approaches that a wide range of researchers have tried to predict crop yield at different [...]
Viscosity of anhydrous and hydrous peridotite melts
Published: 2023-03-24
Subjects: Physical Sciences and Mathematics
The melt viscosity (η) of anhydrous and hydrous peridotite was investigated using a multipronged approach combining micropenetration viscometry, conventional DSC, flash DSC and Brillouin spectroscopy. Raman spectroscopy measurements were used to verify the absence of crystallization and/or degassing during high-temperature measurements of these extremely reactive glasses and melts, ensuring that [...]
“you just look at rocks, and have beards” Perceptions of geology from the UK: a qualitative analysis from an online survey.
Published: 2023-03-24
Subjects: Earth Sciences, Higher Education
In the last few decades, Geology courses, particularly in the Global North have seen a decline in student enrolment. Geologists have linked this downturn to a lack of exposure to the subject at school and college level. This work seeks to understand the public’s relationship with Geology and draws on over 5000 open-ended question responses to a survey disseminated in 2021. The survey asked both [...]
Continental configuration controls the base-state water vapor greenhouse effect: lessons from half-land, half-water planets
Published: 2023-03-24
Subjects: Physical Sciences and Mathematics
The distribution of land and ocean on Earth’s surface shapes the global atmospheric circulation and climate by modulating fluxes of water and energy between the surface and the atmosphere. Here we rearranged land in an idealized climate model to explore the effect of eight simplified continental configurations on global climate, finding several counterintuitive results. The limited capacity of [...]
Sea ice concentration satellite retrievals influenced by surface changes due to warm air intrusions: A case study from the MOSAiC expedition.
Published: 2023-03-24
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Warm air intrusions over Arctic sea ice can rapidly change the snow and ice surface conditions and can alter sea ice concentration (SIC) estimates derived from satellite- based microwave radiometry without altering the true SIC. Here we focus on two warm moist air intrusions that produced surface glazing during the Multidisciplinary drifting Observatory for the Study of Arctic Climate [...]
Can homogeneous nucleation resolve the inner core nucleation paradox?
Published: 2023-03-24
Subjects: Condensed Matter Physics, Earth Sciences, Geophysics and Seismology, Mineral Physics, Planetary Geophysics and Seismology, Planetary Mineral Physics
Rice residue burning trajectories in Eastern India: Current realities, scenarios of change, and implications for air quality
Published: 2023-03-24
Subjects: Life Sciences
In 2019, the Government of India launched the National Clean Air Program (NCAP) to address the pervasive problem of poor air quality and the adverse effect on public health. Coordinated efforts to prevent agricultural burning of crop residues in Northwestern IGP (Indo-Gangetic Plain) have been implemented, but the practice is rapidly expanding into the populous Eastern IGP states, including [...]