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

Preliminary database of Quaternary vents in Alaska

The Alaska Volcano Observatory (AVO) uses an informal set of names for about 140 'volcanoes.' Some names refer to large, complex volcanic centers, while others indicate only a specific cone. This publication expands the list of 140 named volcanoes to include all volcanic vents where magma has reached the surface over the past 2.6 million years. This database of all known (published, or unpublished with permission) Quaternary volcanic vents was developed to better describe the nature and character of Quaternary volcanism in Alaska and specifically to aid in the discussion of spatial and temporal patterns of Alaska volcanism. This list is a preliminary starting point, and we hope that it is updated and expanded by...

Tags: Adak Quadrangle, Alaska Peninsula, Aleutian Islands, Amukta Quadrangle, Atka Quadrangle, All tags... Baird Inlet Quadrangle, Bendeleben Quadrangle, Candle Quadrangle, Chignik Quadrangle, Cold Bay Quadrangle, Cook Inlet, Craig Quadrangle, Fairbanks Quadrangle, False Pass Quadrangle, Gareloi Island Quadrangle, Goodnews Bay Quadrangle, Gulkana Quadrangle, Hazards, Healy Quadrangle, Hooper Bay Quadrangle, Iliamna Quadrangle, Karluk Quadrangle, Kenai Quadrangle, Ketchikan Quadrangle, Kiska Quadrangle, Kotzebue Quadrangle, Kwiguk Quadrangle, Lake Clark Quadrangle, Marshall Quadrangle, McCarthy Quadrangle, Mount Katmai Quadrangle, Nabesna Quadrangle, Naknek Quadrangle, Nunivak Island Quadrangle, Petersburg Quadrangle, Port Moller Quadrangle, Pribilof Islands Quadrangle, Rat Islands Quadrangle, Saint Lawrence Quadrangle, Saint Michael Quadrangle, Samalga Island Quadrangle, Seguam Quadrangle, Selawik Quadrangle, Seward Peninsula, Sitka Quadrangle, Southeast Alaska, Stepovak Bay Quadrangle, Sutwik Island Quadrangle, Tanacross Quadrangle, Tyonek Quadrangle, Ugashik Quadrangle, Umnak Quadrangle, Unalakleet Quadrangle, Unalaska Quadrangle, Unimak Quadrangle, Valdez Quadrangle, Volcanic Eruption, Volcanoes, Volcanology, Wrangell Mountains, geoscientificInformation, Fewer tags