Filters: Tags: Tephra (X) > partyWithName: Alaska Division of Geological & Geophysical Surveys (X)

Filters Date Range Past year (0) Past month (0) Past week (0) Past day (0) Custom range... To   Search Contacts Schaefer, J.R. Scott, W.E. Simone Montayne Layer, P.W. Nye, C.J. More... Tag Types Theme (8) Place (8) Tag Schemes Alaska Division of Geological & Geophysical Surveys (8) ISO 19115 Topic Category (8) View Results as: JSON ATOM CSV

Geology of Kasatochi volcano, Aleutian Islands, Alaska 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... Tags: Active Volcanoes, Age Dates, Aleutian Arc, Aleutian Islands, Alluvial Deposits, All tags... Analyses, Analyses and Sampling, Basalt, Bedrock, Bedrock Geology, Caldera, Chemistry, Colluvium, Erosion, Fan, Geochemical Data, Geochemistry, Geochronology, Geologic, Geologic Hazards, Geologic Map, Geological Process, Geology, Geomorphology, Hazards, Historic Eruption, Igneous, Kasatochi, Lava Flow, Mineralogy, Petrographic, Petrography, Petrology, Pumice, Pyroclastics, Rockfall, Rocks, Sample Location, Slope Instability, Slump, Soils, Surface, Surficial, Talus, Tephra, Topography, Ultramafic, Uplift, Volcanic, Volcanic Ash, Volcanic Eruption, Volcanic Rocks, Volcaniclastics, Volcanoes, Volcanology, geoscientificInformation, Fewer 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... Caldera, Cone A, Cone B, Cone C, Cone D, Cone E, Cone F, Cone G, Cone H, Cone I, Cone J, Fort Glenn, Geologic Hazards, Geomorphology, Geothermal, Groundwater, Heat Flow Study, Historic Eruption, Lahar, Lahar Runout Flow, Lake Level, Okmok, Okmok Caldera, Okmok Hot Springs, Okmok Volcano, Okmok, Mount, Stratigraphy, Surface Water, Tephra, Umnak Island, Umnak Quadrangle, Unalaska Quadrangle, Volcanic Ash, Volcanic Eruption, Volcaniclastics, Volcanology, geoscientificInformation, Fewer tags Geochemistry of some quaternary lavas from the Aleutian Arc and Mt. Wrangell This publication contains previously unpublished geochemical analyses or re-analyses of lavas, magmatic inclusions, and a few gabbroic cumulate inclusions from Alaska volcanoes (Akutan, Augustine, Buzzard Creek, Dana, Douglas, Fourpeaked, Frosty, Great Sitkin, Iliamna, Kaguyak, Kiska, Okmok, Prindle Cone, Recheshnoi, Redoubt, Spurr, Ukinrek Maars, Vsevidof, Westdahl, Wrangell) collected by the authors and others over the past 35 years. It provides substantial data sets for three volcanoes (Vsevidof, Westdahl, and Douglas) for which little or no published data exist. All analyses were made by the GeoAnalytical laboratory at Washington State University in Pullman, WA. The ICP/MS data have been reduced using the 2006... Tags: Adagdak, Adak, Akutan, Analyses, Analyses and Sampling, All tags... Analytical Lab Results, Analytical Results, Augustine, Augustine Volcano, Basalt, Bedrock, Bogoslof, Chemistry, Colorado Creek, Crater Peak, Crystals, Douglas, Faris Peak, Fourpeaked, Frosty, Frosty Peak, Geochemical Data, Geochemistry, Geochronology, Geologic, Geology, Glacier Creek, Hayes, Hazards, Ice, Iliamna, Iliamna Volcano, Jag Peak, Juneau, Kaguyak, Kansas Creek, Kasatochi, Katmai, Kiska, Maars, Mount Douglas, Mount Peulik, Mount Recheshnoi, Mount Spurr, Mount Wrangell, Mount Zanetti, Nikolski, Okmok, Okmok Caldera, Pavlof, Prindle Volcano, Redoubt, Redoubt Volcano, Rhyolite, Rocks, Sample Location, Spurr, Tanana, Tephra, The Sisters, Ukinrek, Ukinrek Maars, Uliaga, Umnak Island, Unimak, Volcanic, Volcanic Arc, Volcanic Rocks, Volcanoes, Volcanology, Vsevidof, Westdahl, Whittier, Wrangell, Yakutat, geoscientificInformation, Fewer tags Geologic map of Mount Chiginagak volcano, Alaska Mount Chiginagak is a hydrothermally active volcano on the Alaska Peninsula, approximately 170 km south-southwest of King Salmon, Alaska. This small stratovolcano, approximately 8 km in diameter, has erupted through Tertiary to Permian sedimentary and igneous rocks. The eruptive products of Chiginagak volcano record a history of chiefly andesite lava flows and associated block-and-ash flows. The oldest lavas exposed are Pleistocene in age and are found everywhere around the edifice except in the northeast sector, where Holocene lava flows dominate the landscape. Holocene activity has covered the northeast flank with rubbly-topped andesite lava flows that extend as far as 4.6 km from their source vent at the summit... Tags: Alaska Peninsula, Aleutian Range, Analyses, Chiginagak, Gas, All tags... Geochemistry, Geochronology, Geologic, Geology, Hazards, Igneous, Lahar, Mount Chiginagak, Neoglacial, Pumice, Rocks, Sediment, Sulfur, Surface, Surficial, Tephra, Ugashik Quadrangle, Volcanic, Volcanic Ash, Volcanic Eruption, Volcanic Gas, Volcanic Rocks, Volcaniclastic Deposits, Volcaniclastics, Volcanoes, Volcanology, Water, geoscientificInformation, Fewer tags Geologic map of Mount Chiginagak volcano, Alaska Mount Chiginagak is a hydrothermally active volcano on the Alaska Peninsula, approximately 170 km south-southwest of King Salmon, Alaska. This small stratovolcano, approximately 8 km in diameter, has erupted through Tertiary to Permian sedimentary and igneous rocks. The eruptive products of Chiginagak volcano record a history of chiefly andesite lava flows and associated block-and-ash flows. The oldest lavas exposed are Pleistocene in age and are found everywhere around the edifice except in the northeast sector, where Holocene lava flows dominate the landscape. Holocene activity has covered the northeast flank with rubbly-topped andesite lava flows that extend as far as 4.6 km from their source vent at the summit... Tags: Alaska Peninsula, Aleutian Range, Analyses, Chiginagak, Gas, All tags... GeMS NCGMP09, Geochemistry, Geochronology, Geologic, Geology, Hazards, Igneous, Lahar, Mount Chiginagak, Neoglacial, Pumice, Rocks, Sediment, Sulfur, Surface, Surficial, Tephra, Ugashik Quadrangle, Volcanic, Volcanic Ash, Volcanic Eruption, Volcanic Gas, Volcanic Rocks, Volcaniclastic Deposits, Volcaniclastics, Volcanoes, Volcanology, Water, geoscientificInformation, Fewer tags Preliminary volcano-hazard assessment for Fisher volcano, Unimak Island, Alaska 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... Tags: Active Volcanoes, Aleutian Arc, Aleutian Islands, Ash Cloud, Ash Fall, All tags... Ballistics, Caldera, Debris Flow, Fisher, Flood, Geologic Hazards, Geothermal, Hazards, Lahar, Lava Flow, Pumice, Pyroclastic Flow, Pyroclastic Surge, Tephra, Unimak Quadrangle, Volcanic Ash, Volcanic Gas, Volcaniclastics, Volcanology, geoscientificInformation, Fewer tags Geology of Kasatochi volcano, Aleutian Islands, Alaska 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... Tags: Active Volcanoes, Age Dates, Aleutian Arc, Aleutian Islands, Alluvial Deposits, All tags... Analyses, Analyses and Sampling, Basalt, Bedrock, Bedrock Geology, Caldera, Chemistry, Colluvium, Erosion, Fan, Geochemical Data, Geochemistry, Geochronology, Geologic, Geologic Hazards, Geologic Map, Geological Process, Geology, Geomorphology, Hazards, Historic Eruption, Igneous, Kasatochi, Lava Flow, Mineralogy, Petrographic, Petrography, Petrology, Pumice, Pyroclastics, Rockfall, Rocks, Sample Location, Slope Instability, Slump, Soils, Surface, Surficial, Talus, Tephra, Topography, Ultramafic, Uplift, Volcanic, Volcanic Ash, Volcanic Eruption, Volcanic Rocks, Volcaniclastics, Volcanoes, Volcanology, geoscientificInformation, Fewer tags Major-element glass compositions of tephra from the circa 3.6 ka eruption of Aniakchak volcano, Alaska Peninsula, Alaska 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... Tags: Alaska Peninsula, Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, All tags... Aniakchak, Archaeology, Caldera, Coastal, Geochemistry, Geologic, Geology, Glass, Hazards, Methods, Minerals, Tephra, Tephrochronology, Tephrostratigraphy, Volcanic, Volcanoes, Volcanology, geoscientificInformation, Fewer tags