Schaefer, J.R.

14 items:

Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2011 Following the May 2005 acid crater lake flood at Chiginagak volcano, DGGS has been monitoring crater lake water that flows into Indecision Creek, Mother Goose Lake, and the King Salmon River.This data table provides information on water samples collected between 2005 and 2011 near Chiginagak volcano, including:sample ID, latitude, longitude, location description, pH, and cation and anion chemistry results. Tags: Chiginagak, Indecision Creek, Inorganic Contamination, King Salmon River, Mother Goose Hot Springs, All tags...
Historically active volcanoes of Alaska This data lists the historically active volcanoes of Alaska and the year of the last major eruptive event. The volcanoes listed meet at least one of the following criteria since 1700 CE: (1) documented, unquestioned eruption, or (2) a strongly suspected eruption, often an eruption documented in the historical account with very little information (current geologic knowledge must not contradict the eruption account), or (3) persistent (usually on the order of decades, but certainly longer than several months) fumaroles, with temperatures (where measured) within ~10 degrees C of the boiling point, or (4) significant, measured, volcanic-related, non-eruptive deformation, (5) documented earthquake swarm with strongly... Tags: Active Volcanoes, Alaska Peninsula, Alaska Statewide Maps, Alaska, State of, Aleutian Arc, All tags...
The 2008 phreatomagmatic eruption of Okmok Volcano, Aleutian Islands, Alaska: Chronology, deposits, and landform changes Okmok volcano, Aleutian Islands, Alaska, explosively erupted over a five-week period between July 12 and August 23, 2008. The eruption was predominantly phreatomagmatic, producing fine-grained tephra that covered most of northeastern Umnak Island. The eruption had a maximum Volcanic Explosivity Index (VEI) of 4, with eruption column heights up to 16 km during the opening phase. Several craters and a master tuff cone formed in the caldera as a result of phreatomagmatic explosions and accumulated tephra-fall and surge deposits. Ascending magma continuously interacted with an extensive shallow groundwater table in the caldera, resulting in the phreatomagmatic character of the eruption. Syneruptive explosion and collapse... Tags: Active Volcanoes, Aleutian Arc, Aleutian Islands, Ash Cloud, Ash Fall, All tags...
Preliminary bathymetric map of Mother Goose Lake, Alaska Peninsula In preparation for bottom sediment coring at Mother Goose Lake, bathymetric data was collected using a Lowrance Sonar "fishfinder" (model LcX-17M) in August 2006 and August 2007. A 5-meter bathymetric contour map of the lake bottom was constructed using the GPS-sonar data in conjunction with field observations. The contour data and GPS location and depth data are provided in ESRI shapefile format for use in Geographic Information System (GIS) software. Tags: Alaska Peninsula, Bathymetry, Chiginagak, Lacustrine, Mother Goose Lake, All tags...
Preliminary volcano-hazard assessment for Okmok Volcano, Umnak Island, Alaska This dataset consists of the vector digital GIS files that were used to create sheet 1 of the "Preliminary volcano-hazard assessment for Okmok Volcano, Umnak Island, Alaska" (DGGS RI 2004-3). The map area is centered around Okmok Volcano, on eastern Umnak Island. The data includes volcano-hazard zones for ballistics, ash accumulation, pyroclastic flows, floods and lahars, and debris avalanches. Also included in the dataset are roads, trails, seismic station locations, continuous GPS station locations, creeks, and the location of the Fort Glenn airstrip. Tags: Aleutian Arc, Aleutian Islands, Fort Glenn, Fox Islands, Okmok Caldera, All tags...

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