Filters: Tags: Tephra (X)
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Fisher volcano, containing the largest Holocene caldera in the Aleutian volcanic arc, is an active volcano near the center of Unimak Island, about 120 kilometers southwest of Cold Bay and about 175 kilometers northeast of Dutch Harbor. The volcano is composed of numerous small volcanic centers around and within a large, oval caldera 12 by 18 kilometers in diameter and 500 to 1,000 meters deep that formed during a catastrophic eruption about 9,400 years ago. Since then, more than 30 separate vents inside and outside the caldera have erupted; the most recent eruption occurred in 1826. These eruptions have produced lava flows and widespread tephra (volcanic ash) deposits, and have occasionally been accompanied by large...
This data release contains model input and output for 57 simulations of tephra dispersal during the 7.8 ka Mazama eruption. Data were generated during in preparation of the following paper: Buckland HM, Mastin L, Engwell S, Cashman K (2022 (in pess)) Modelling the transport and deposition of ash following a Magnitude 7 eruption: the distal Mazama tephra. Bull Volcanol. 84(9):87. https://doi.org/10.1007/s00445-022-01593-1
The California volcano locations, threat rank and hazard zones data release contains two shapefiles for download or use as a web map service. The California Volcanic Center Locations shapefile was created to provide a generalized location of volcano hazard sources. The California Volcano Hazard Zones shapefile was created from previously published hazard zone reports. Specific details about each file can be found in the metadata included with each file and the read-me document for this data release. Together, these files were used to define California Volcano Hazards for the GIS analysis that supports conclusions in the California's exposure to volcano hazards report. Geologists produce hazard zone maps to convey...
Categories: Data;
Types: ArcGIS REST Map Service,
ArcGIS Service Definition,
Downloadable,
Map Service;
Tags: Alpine County,
Ash,
Ballistic,
Butte County,
California,
Kasatochi is a small, isolated island volcano in the center of the Aleutian Island chain. It consists of a roughly circular cone approximately 3 km in diameter with a lake-filled central crater that is 1.2 km in diameter and extends from the highest point on the island to sea level. The oldest unit recognized is a thick series of mid-Pleistocene glaciovolcanic deposits consisting of autobrecciated lava, lahars, and volumetrically minor lava masses that we believe to have been emplaced underneath a regional ice cap. This unit is unconformably overlain by several massive Holocene lavas, above which lies a thick sequence of latest-Holocene pyroclastic deposits likely deposited during the crater-forming eruption. The...
This Raw Data File presents major-oxide glass geochemical results from the ca. 3.6 ka caldera-forming eruption of Aniakchak volcano, Alaska. These data are part of a larger effort to identify and characterize tephra deposits from the largest eruptions in Alaska for use as geochronological marker horizons. Aniakchak is one of at least 29 volcanoes in Alaska that has had multiple large tephra-producing eruptions. Other deposit and sample metadata including geospatial distributions of this tephra deposit are held in the Alaska Volcano Observatory's online database, the Geologic Database of Information on Volcanoes in Alaska (GeoDIVA), and will be linked to these new geochemical data once published. Products included...
This dataset includes sample information, vesicularity by pycnometer, grain size and shape data by CAMSIZER, and measurements of crushed and thin section mounted grains by microscope. All studied samples were from scoria and air-fall-tephra deposits (most formed in Hawaiian lava fountains) collected around the summits of Mauna Loa and Kīlauea volcanoes, Island of Hawaiʻi. These data were used to derive methods for quickly being able to quantify vesicularity in near-real-time during an eruption response. The samples from Kīlauea all erupted from the summit area and include Keanakākoʻi units B, D, E, K1, and K2, the Halemaʻumaʻu eruptions in September 2021 and September 2023, and the Kīlauea Iki eruption that formed...
Categories: Data;
Tags: Island of Hawaiʻi,
Kīlauea,
Mauna Loa,
Tephra,
USGS Science Data Catalog (SDC),
These tables contain geochemical data collected for tephra samples either correlated with or in the same type section with the Ibex Hollow Tuff. Most samples were collected by Andrei Sarna-Wojcicki and Mike Perkins, but some were submitted to the U.S. Geological Survey Tephrochronology Project for analysis by other persons. Electron microprobe analysis (EMA) was performed at the U.S. Geological Survey in Menlo Park California, at the University of Utah in Salt Lake City Utah, and at the University of Toronto in Toronto Ontario Canada. Bulk glass EMA results have been normalized to 100% anhydrous following standard normalization procedures. Individual shard analyses are unnormalized. Instrumental neutron activation...
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alabama,
California,
Geochemistry,
Idaho,
Kansas,
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