Preprints
There are 4725 Preprints listed.
Radiative feedbacks on land surface change and associated tropical precipitation shifts
Published: 2020-11-18
Subjects: Physical Sciences and Mathematics
Changes in land surface albedo and land surface evaporation modulate the atmospheric energy budget by changing temperatures, water vapor, clouds, snow and ice cover, and the partitioning of surface energy fluxes. Here idealized perturbations to land surface properties are imposed in a global model to understand how such forcings drive shifts in zonal mean atmospheric energy transport and zonal [...]
Global lockdown potential impact on achieving Sustainable Development Goals
Published: 2020-11-17
Subjects: Environmental Studies, Life Sciences
Coronavirus disease (COVID-19) pandemic has led to a lockdown worldwide. This restriction on human movements and activities significantly influences society and the environment. We examined the consequences of global lockdown for human movement and nitrogen dioxide (NO2) emissions using an air pollution index and dataset and satellite image analyses. We also evaluated the immediate (during [...]
International Meeting 40 years of the 1980 Azores Earthquake, 6th - 7th October 2020 - Conference Report
Published: 2020-11-16
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Geophysics and Seismology, Other Civil and Environmental Engineering
The main goal of the International Meeting “40 Years of the 1980 Azores Earthquake” was promoting a reflection of the earthquake of January 1st, 1980, and the advances since them on topics like seismology, seismic hazard, and risk, building rehabilitation and public policies. Nevertheless, due to the COVID-19 outbreak, the organizing committee decided that the meeting should be online and [...]
A global Bayesian temperature calibration for lacustrine brGDGTs
Published: 2020-11-14
Subjects: Biogeochemistry, Climate
Despite widespread use of branched glycerol dialkyl glycerol tetraethers (brGDGTs) for paleo-temperature reconstruction, no global calibration for their application in lakes has been generated since improved analytical methods have allowed for the separation of the structural isomers. This is a substantial obstacle for the application of this tool as soil calibrations underestimate temperature [...]
Boron isotopic signatures of melt inclusions from North Iceland reveal recycled material in the Icelandic mantle source
Published: 2020-11-14
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Volcanology
Trace element and volatile heterogeneity in the Earth's mantle is in uenced by the recycling of oceanic lithosphere through subduction. Oceanic island basalts commonly have high concentrations of volatiles compared to mid-ocean ridge basalts, but the extent to which this enrichment is linked to recycled mantle domains remains unclear. Boron is an ideal tracer of recycled subducted material, [...]
Backstresses from dislocation interactions quantified by nanoindentation load-drop experiments
Published: 2020-11-14
Subjects: Physical Sciences and Mathematics
Recent work has identified the importance of strain hardening and backstresses among dislocations in the deformation of geologic materials at both high and low temperatures, but very few experimental measurements of such backstresses exist. Using a nanoindentation load-drop method and a self-similar Berkovich tip, we measure backstresses in single crystals of olivine, quartz, and plagioclase [...]
The Influence of Dust Levels on Atmospheric Carbon Dioxide and Global Temperature
Published: 2020-11-13
Subjects: Physical Sciences and Mathematics
The purpose of this paper is to examine the causality between DUST, CO2 and temperature for the Vostok ice core data series [Vostok Data Series], dating from 420 000 years ago, and the EPICA C Dome data going back 800 000 years. In addition, the time-varying volatility and coefficient of variation in the CO2, dust and temperature is examined, as well as their dynamic correlations and [...]
Microseismicity appears to outline highly coupled regions on the Central Chile megathrust
Published: 2020-11-13
Subjects: Physical Sciences and Mathematics
We compiled a novel microseismicity catalog for the Central Chile megathrust (29-35◦S), comprising 8750 earthquakes between 04/2014 and 12/2018. These events describe a pattern of three trenchward open half-ellipses, consisting of a continuous, coast-parallel seismicity band at 30-45 km depth, and narrow elongated seismicity clusters that protrude to the shallow megathrust and separate largely [...]
ENSO Drives Child Undernutrition in the Global Tropics
Published: 2020-11-13
Subjects: Applied Statistics, Climate, Environmental Public Health, Environmental Sciences, Environmental Studies, Other Environmental Sciences, Public Health, Social and Behavioral Sciences, Sustainability
The El Nino Southern Oscillation (ENSO) is a principal component of global climate variability known to influence a host of social and economic outcomes, but its systematic effects on human health remain poorly understood. We estimate ENSO’s association with child nutrition at global scale by combining variation in ENSO intensity from 1986-2018 with children’s height and weight from 186 surveys [...]
On the use of rock physics models for studying the critical zone
Published: 2020-11-12
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology
How effective are rock physics models for relating seismic velocities to the physical properties of sediments, fluids, and cement within the critical zone, and what factors most substantially influence the models’ accuracies? We answer these questions by testing and analyzing the accuracies of seven rock physics models (Hertz-Mindlin, Walton, Jenkins, Digby, stiff sand, soft sand, and contact [...]
The effects of 180 years of aging on the physical and seismic properties of partially saturated sands
Published: 2020-11-12
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics, Sedimentology
Constraining how the physical properties and seismic responses of recently deposited sands change with time is important for understanding earthquake site response, subsurface fluid flow, and early stages lithification. Currently, however, there is no detailed (cm-scale) assessment of how sand physical properties and associated seismic velocities evolve over the first two centuries after [...]
Radiocarbon Protocols and First Intercomparison Results from the Chronos 14Carbon-Cycle Facility, University of New South Wales, Sydney, Australia
Published: 2020-11-12
Subjects: Physical Sciences and Mathematics
The Chronos 14Carbon-Cycle Facility is a new radiocarbon laboratory at the University of New South Wales, Australia. Built around an Ionplus 200 kV MIni-CArbon DAting System (MICADAS) Accelerator Mass Spectrometer (AMS) installed in October 2019, the facility was established to address major challenges in the Earth, Environmental and Archaeological sciences. Here we report an overview of the [...]
Optimizing Crop Cut Collection for Determining Field-Scale Yields in an Insurance Context
Published: 2020-11-10
Subjects: Geographic Information Sciences, Geography, Other Engineering, Remote Sensing, Spatial Science
Accurately determining crop yields at field-scale can help farmers estimate their net profit, enable insurance companies to ascertain payouts, and when aggregated at regional and national scales, crop yield estimates are critical in ensuring food security. Over the last few decades, crop cuts have been widely used to estimate field-scale crop yields. Crop cuts, while cost prohibitive, are the [...]
Ventilation of the abyss in the Atlantic sector of the Southern Ocean
Published: 2020-11-10
Subjects: Oceanography
The Atlantic sector of the Southern Ocean is the world’s main production site of Antarctic Bottom Water, a water-mass that is ventilated at the ocean surface before sinking and entraining older water-masses – ultimately replenishing the abyssal global ocean. In recent decades, numerous attempts at estimating the rates of ventilation and overturning of Antarctic Bottom Water in this region have [...]
Evaluating the geochemistry and paired silicon and oxygen isotope record of quartz in siliceous rocks from the ~3 Ga Buhwa Greenstone Belt, Zimbabwe, a critical link to deciphering the Archean silica cycle
Published: 2020-11-10
Subjects: Physical Sciences and Mathematics
The balance of the Archean silica cycle links fundamentally to large scale processes that govern the composition of the ocean. Shifting contributions from continental or hydrothermal inputs of silica to the ocean is commonly recorded in silica-rich chemical precipitates. Such information is critical to interpreting primordial conditions in early life environments but reading the archive of [...]