Filters: Tags: Volcanic Ash (X) > Categories: Data (X)
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A total of 100 samples were collected from two proximal sections of Keanakākoʻi, Tephra unit D deposits. Samples were analyzed on Microtrac CAMSIZER® P4 and X2 instruments for grain size and shape data in the USGS Hawaiian Volcano Observatory (HVO) tephra lab. Data release includes sample descriptions, half phi grain size distributions, and statistical output from DECOLOG deconvolution modeling of grain size distributions. Grain size is reported using the sieve compatible Xcmin parameter (CAMSIZER® manual, 2020). Data of 2D shape parameter means of sphericity, Krumbein roundness and compactness of samples as well as for half phi grain size bins at 4, 3, 2, 1, 0, and -1 phi are also included. Please refer to associated...
Categories: Data;
Tags: Camsizer,
Grain shape,
Grain size,
Hawaii Volcanoes National Park,
Kīlauea Volcano,
This data collection includes ground-penetrating radar (GPR) data and related observations collected from the NASA Goddard Instrument Field Team (GIFT) Expedition to the Icelandic Highlands in July-August 2019 and August 2021. This dataset includes observations at the Askja Volcano and caldera and Vikrahraun lava flow. GPR data were collected using Geophysical Survey Systems, Inc (GSSI) shielded bistatic antennas at center frequencies of 200 MHz, 400 MHz, and 900 MHz. Common offset surveys were conducted to investigate the subsurface interfaces. The GPR data includes raw data obtained from the instrument (as GSSI .dzt files), line shapefiles of survey locations, and interpreted ice thickness GeoPackage files with...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Askja,
Iceland,
USGS Science Data Catalog (SDC),
Volcanic ash,
caldera,
In early May 2018, activity at Kīlauea volcano, Hawaii, increased, with heightened ash production from the summit commencing on May 17. Volcanic ash can scavenge volatile components from volcanic plumes, resulting in the deposition of potentially harmful elements during ash fallout. Leaching of these species (e.g., by rainfall or in water catchment systems) can have implications for agriculture, water resources and human health. The U.S. Geological Survey (USGS) is sampling volcanic ash and utilizing ash leachate analyses as part of the assessment of hazards from the ongoing eruption of Kīlauea Volcano. We acquired 30 ash samples erupted from the summit of Kīlauea Volcano and collected downwind between May 10...
Categories: Data;
Tags: Environmental Health,
Environmental hazards,
Environmental health,
Hawaiʻi Volcanoes National Park,
Human health,
This 1:50,000-scale geologic map represents a compilation of the most recent geologic studies of the upper Arkansas River valley, between Leadville and Salida, Colorado. The valley is structurally controlled by an extensional fault system that forms part of the prominent northern Rio Grande rift, an intra-continental region of crustal extension. This work also incorporates new detailed geologic mapping of poorly understood areas within the map area and reinterprets previously studied areas, aided by lidar data that covers 59 percent of the map area. The mapped region extends into the Proterozoic metamorphic and intrusive rocks in the Sawatch Range west of the valley and the Mosquito Range to the east. Paleozoic...
Categories: Data;
Tags: 207Pb/206Pb zircon age,
40Ar/39Ar age,
Arkansas River,
Balltown,
Balltown placer gold mining areas,
These data are presented to geochemically characterize glass from the informally named Khonkho tephra, an ashfall deposit that crops out at the Khonkho Wankane archaeological site in Jesus de Machaca, Bolivia. The Khonkho tephra appears to have been emplaced by a major explosive eruption from a currently unknown volcanic source. The unit forms a marker bed at an archaeologically important stratigraphic level. These data are to accompany a publication that describes the tephra-fall deposit and its implications and will eventually be used to correlate the unit to samples from other locations where it crops out and to identify its source volcano and eruption. Any use of trade, firm, or product names is for descriptive...
Categories: Data;
Tags: Archaeology,
Bolivia,
Geochemical analysis,
Geochemistry,
Glass composition,
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