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The purpose of this study is to evaluate tsunami hazard for the community of Seward and northern Resurrection Bay area, Alaska. This report will provide guidance to local emergency managers in tsunami hazard assessment. We used a numerical modeling method to estimate the extent of inundation by tsunami waves generated from earthquake and landslide sources. Our tsunami scenarios included a repeat of the tsunami of the 1964 Great Alaska Earthquake, as well as tsunami waves generated by two hypothetical Yakataga Gap earthquakes in northeastern Gulf of Alaska, hypothetical earthquakes in Prince William Sound and Kodiak asperities of the 1964 rupture, and local underwater landslides in Resurrection Bay. Results of numerical...
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Potential tsunami hazards for the Fox Islands communities of Unalaska/Dutch Harbor and Akutan were evaluated by numerically modeling the extent of inundation from tsunami waves generated by hypothetical earthquake sources and taking into account historical observations. Worst-case hypothetical scenarios are defined by analyzing results of a sensitivity study of the tsunami dynamics related to various slip distributions along the Aleutian megathrust. The worst-case scenarios for Unalaska and Akutan are thought to be thrust earthquakes in the Fox Islands region with magnitudes ranging from Mw 8.8 to Mw 9.1 that have their greatest slip at 30-40 km (18-25 mi) depth. We also consider Tohoku-type ruptures and an outer-rise...
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Staff from Alaska Earthquake Center, Geophysical Institute and Alaska Division of Geological & Geophysical Surveys evaluated potential tsunami hazards for the city of Sand Point, on Popof Island in the Shumagin Islands archipelago. We numerically modeled the extent of inundation from tsunami waves generated by local and distant earthquake sources. We considered the results in light of historical observations. The worst-case scenarios are defined by analyzing results of the sensitivity study of the tsunami dynamics with respect to different slip distributions along the Aleutian megathrust. For the Sand Point area, the worst-case scenarios are thought to be thrust earthquakes in the Shumagin Islands region with magnitudes...
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This dataset contains information and locations on faults and associated folds in Alaska that are believed to be sources of M>6 earthquakes during the Quaternary (the past 1,600,000 years). The dataset is intended to part of the USGS archive for historic and ancient earthquake sources used in current and future probabilistic seismic-hazard analyses. This dataset presents a single source that summarizes important information on paleoseismic (ancient earthquakes) parameters including, age of most recent deformation, slip rate, slip sense dip direction, and accuracy of original mapping. These data are compiled from hundreds of journal articles, maps, theses, and other documents, as referenced herein. The geospatial...
This release is an update to the online "Quaternary fault and fold database" for Washington State. The online database was last updated for Washington in 2014 – this 2020 update includes newly identified and modified traces and geometries for on-shore faults gleaned from new peer-reviewed studies and mapping of active faults within the state of Washington. These data contain lines representing the location of faults with known or suspected Quaternary (<1,600,000 yrs) activity in the state of Washington. This data was compiled in conjunction with the Washington State Geological Survey. Faults are attributed following the Quaternary fault and fold database attributes, including information such as age, slip sense,...
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This report provides detailed (1:63,360-scale) mapping of the Tanana A-1 and A-2 quadrangles (500 square miles; equivalent to eight 7.5-minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the south of the Tanana B-1 Quadrangle. This report includes detailed bedrock, surficial, structural, and stratigraphic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the report also includes derivative maps of geologic construction materials and geologic hazards. The Tanana A-1 and A-2 Quadrangles and surrounding area comprise several isolated mountainous ridges in the western Yukon-Tanana Upland...
Tags: 40Ar/39Ar, Aerial Photography, Aeromagnetic Map, Aeromagnetic Survey, Age Dates, All tags...
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Potential tsunami hazard for the Umnak Island community of Nikolski is evaluated by numerically modeling the extent of inundation from tsunami waves generated by hypothetical earthquake sources. Worst-case hypothetical scenarios are defined by analyzing results of a sensitivity study of the tsunami dynamics related to various slip distributions along the Aleutian megathrust. The worst-case scenarios for Nikolski are thought to be thrust earthquakes in the Umnak Island region with their greatest slip at 10-30 km (6.2-19 mi) depth. We also consider Tohoku-type ruptures and an outer-rise rupture in the area of Umnak Island. The maximum predicted water depth on Main Street is about 15 m (49 ft), while the maximum current...
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This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes a derivative map of potential geologic hazards based on the resulting geologic maps, field investigations, and laboratory materials analyses.
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This report provides detailed (1:63,360-scale) mapping of portions of U.S. Geological Survey Circle B-2 (1955), B-3 (1955), B-4 (1952), C-2 (1955), C-3 (1955), and C-4 (1952) quadrangles. The area is part of the Circle mining district and adjacent to the Fairbanks mining district. This report includes detailed geologic, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.
Tags: Aereal, Aerial Photography, Aeromagnetic Survey, Age Dates, Alaska, State of, All tags...
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In this report, we evaluate potential tsunami hazards for southeastern Alaska communities of Elfin Cove, Gustavus, and Hoonah and numerically model the extent of inundation from tsunami waves generated by tectonic and landslide sources. We perform numerical modeling of historic tsunami events, such as the tsunami triggered by the 1964 Great Alaska Earthquake, and the tsunami waves generated by the recent 2011 Tohoku and 2012 Haida Gwaii earthquakes. Hypothetical tsunami scenarios include variations of the extended 1964 rupture, megathrust earthquakes in the Prince William Sound and Alaska Peninsula regions, and a Cascadia megathrust earthquake. Local underwater landslide events in Taylor Bay and Port Frederick,...
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The Alaska Division of Geological & Geophysical Surveys (DGGS), in partnership with the U.S. National Cooperative Geologic Mapping Program, mapped approximately 450 mi2 of the Talkeetna Mountains region of central Alaska at 1:50,000 scale over the course of six weeks in 2014. This area contains significant exposures of Late Triassic mafic volcanics and gabbro sills that have been the focus of region-wide exploration for the Strategic and Critical platinum-group elements (PGEs). The area also exposes numerous inactive and possibly active faults which project through the area of proposed hydropower development. The resulting geologic map offers an improved understanding of the geology, structural history, and mineral...
Tags: 40Ar/39Ar, Aerial Geology, Aerial Photography, Alluvial, Alluvial Deposits, All tags...
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This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes detailed bedrock, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.
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Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Sagavanirktok B-1 Quadrangle (640 square km´┐Żequivalent to four 7.5 minute quadrangles). This mapping project reinterprets micropaleontologic correlations for 17 Sagavanirktok Quadrangle wells, and reprocesses data from the one publicly-available seismic line. Surface geologic mapping, subsurface-to-surface stratigraphic age control, and seismic framework are required to reliably decipher the complex geology of this key area of the Brooks Range. Outcrops within the Sagavanirktok B-1 Quadrangle are the closest surface expressions of Prudhoe Bay source and reservoir rocks. This study yields critical petroleum-related...
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We evaluate potential tsunami hazards for the city of Valdez and numerically model the extent of inundation from tsunamis generated by earthquake and landslide sources. Tsunami scenarios include a repeat of the tsunami triggered by the 1964 Great Alaska Earthquake, as well as hypothetical tsunamis generated by an extended 1964 rupture, a Cascadia megathrust earthquake, and earthquakes from the Prince William Sound and Kodiak asperities of the 1964 rupture. Local underwater landslide events in Port Valdez are also considered as credible tsunamigenic scenarios. Results of numerical modeling are verified by simulating the tectonic and landslide-generated tsunamis in Port Valdez observed during the 1964 earthquake....
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Alaska is the most seismically active region of the United States. However, little information exists on the location, style of deformation, and slip rates of Quaternary faults. This interactive map displays locations and relative activity of Alaska's faults and folds. The map offers zoom and scroll options, and multiple base map layers. Click individual fault and fold traces to view basic fault parameters: name, age, slip rate, slip sense, dip direction, mapping certainty, and mapped scale. This resource is intended to provide simple and quick means of visualizing structure locations and characteristics. Users must recognize mapping certainty and data accuracy limitations when zooming in farther than the stated...
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The purpose of this study was to evaluate a potential tsunami risk for communities of Homer and Seldovia in the Kachemak Bay area, Alaska. This report provides guidance to the local emergency managers in tsunami hazard assessment. We used a numerical modeling method to estimate the extent of inundation due to tsunami waves generated by earthquake sources. Our tsunami scenarios included a repeat of the tsunami of the 1964 great Alaska earthquake, as well as a hypothetical tsunami wave generated by a local fault source. We didn't consider landslide-generated tsunamis in this study. Results of numerical modeling combined with historical observations in the region are intended to help local emergency services officials...
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The purpose of this study is to evaluate potential tsunami hazards for the community of Whittier and western Passage Canal area. We numerically model the extent of inundation due to tsunami waves generated from earthquake and landslide sources. Tsunami scenarios include a repeat of the tsunami triggered by the 1964 Great Alaska Earthquake, as well as tsunami waves generated by a hypothetically extended 1964 rupture, a hypothetical Cascadia megathrust earthquake, hypothetical earthquakes in Prince William Sound, and Kodiak asperities of the 1964 rupture. Local underwater landslide and rockslide events in Passage Canal are also considered as credible tsunamigenic scenarios. Results of numerical modeling combined with...
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In 2005, the Alaska Division of Geological & Geophysical Surveys initiated a multi-year geologic field study focused on a corridor centered along the Alaska Highway between Delta Junction and the Canada border. The purpose of this project is to provide geologic information relevant to a proposed Alaska-Canada natural gas pipeline and other future development in the corridor. The scope of this project includes identification of active faults and characterization of seismic hazards. During the 2008 field season the active fault studies were focused on the central part of the corridor between Dot Lake and Tetlin Junction. Field studies included helicopter and fixed-wing air reconnaissance augmented by interpretation...
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The purpose of this study is to evaluate potential tsunami hazards for the community of Sitka. We numerically modeled the extent of inundation from tsunami waves generated by near- and far-field tectonic sources. We performed numerical modeling of historic events at Sitka, such as the tsunami triggered by the 1964 Great Alaska Earthquake, and the tsunami waves generated by the recent 2011 Tohoku and 2012 Haida Gwaii earthquakes. Hypothetical tsunami scenarios include variations of the extended 1964 rupture, megathrust earthquakes in the Alaska Peninsula region and in the Cascadia subduction zone, and a thrust earthquake in the region of the Queen Charlotte-Fairweather fault zone. Results of numerical modeling combined...


map background search result map search result map Quaternary Faults and Folds (QFF) Quaternary faults and folds in Alaska: A digital database Geologic map of the Tanana A-1 and A-2 quadrangles, central Alaska Geologic map of the Dalton Highway (Atigun Gorge to Slope Mountain) area, southern Arctic Foothills, Alaska Active and potentially active faults in or near the Alaska Highway corridor, Dot Lake to Tetlin Junction, Alaska Geologic map of the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska Geologic map of the Circle mining district, Alaska Interpretive geologic bedrock map of the Tanana B-1 Quadrangle, Central Alaska Derivative map of potential geologic hazards in the Tanana B-1 Quadrangle, Alaska Interpretive bedrock-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Tsunami hazard maps of the Homer and Seldovia areas, Alaska Tsunami inundation maps of Seward and northern Resurrection Bay, Alaska Tsunami inundation maps of Whittier and western Passage Canal, Alaska Tsunami inundation maps of Port Valdez, Alaska Tsunami inundation maps of Sitka, Alaska Tsunami inundation maps of Elfin Cove, Gustavus, and Hoonah, Alaska Tsunami inundation maps of Fox Islands communities, including Dutch Harbor and Akutan, Alaska Tsunami inundation map for the village of Nikolski, Alaska Tsunami inundation maps for the city of Sand Point, Alaska 2020 Update to the Quaternary Fault and Fold Database for Washington State Tsunami inundation maps of Whittier and western Passage Canal, Alaska Tsunami inundation maps for the city of Sand Point, Alaska Tsunami inundation maps of Seward and northern Resurrection Bay, Alaska Tsunami inundation map for the village of Nikolski, Alaska Tsunami inundation maps of Sitka, Alaska Tsunami inundation maps of Port Valdez, Alaska Tsunami hazard maps of the Homer and Seldovia areas, Alaska Interpretive geologic bedrock map of the Tanana B-1 Quadrangle, Central Alaska Derivative map of potential geologic hazards in the Tanana B-1 Quadrangle, Alaska Interpretive bedrock-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Geologic map of the Dalton Highway (Atigun Gorge to Slope Mountain) area, southern Arctic Foothills, Alaska Tsunami inundation maps of Elfin Cove, Gustavus, and Hoonah, Alaska Active and potentially active faults in or near the Alaska Highway corridor, Dot Lake to Tetlin Junction, Alaska 2020 Update to the Quaternary Fault and Fold Database for Washington State Quaternary faults and folds in Alaska: A digital database Quaternary Faults and Folds (QFF)