Now showing items 1-20 of 23

    • Alaska Earthquake Center Quarterly Technical Report April-June 2021

      Ruppert, Natalia (2021-08)
      This series of technical quarterly reports from the Alaska Earthquake Center (AEC) includes detailed summaries and updates on Alaska seismicity, the AEC seismic network and stations, field work, our social media presence, and lists publications and presentations by AEC staff. Multiple AEC staff members contributed to this report. It is issued in the following month after the completion of each quarter Q1: January-March, Q2: April-June, Q3: July-September, and Q4: October-December.
    • Alaska Earthquake Center Quarterly Technical Report January-March 2021

      Ruppert, Natalia (2021-05)
      This is the first in a series of technical quarterly reports from the Alaska Earthquake Center (AEC). It includes detailed summaries and updates on Alaska seismicity, the AEC seismic network and stations, field work, our social media presence, and lists publications and presentations by AEC staff. Multiple AEC staff members contributed to this report. It is issued in the following month after the completion of each quarter Q1: January-March, Q2: April-June, Q3: July-September, and Q4: October-December.
    • Alaska Earthquake Center: A 2020 Perspective

      Grassi, Beth; West, Michael; Gardine, Lea (2021-03)
      The Alaska Earthquake Center is not historically in the habit of producing annual reports. We are in a dynamic time, however. Societally-significant earthquakes and multiple tsunami concerns over the past few years have brought more attention to what we do. At the same time, we are experiencing significant growth in several areas. Our goal in distributing this summary is to communicate the breadth of our activities and the diversity of our stakeholders, helping us become even more effective at meeting the earthquake and tsunami science needs of Alaska and the nation.
    • 2020 Alaska Seismicity Summary

      Ruppert, Natalia A.; Gardine, Lea (2021-02)
      The Alaska Earthquake Center reported about 49,250 seismic events in Alaska and neighboring regions in 2020. The largest earthquake was a magnitude 7.8 event that occurred on July 22 in the Shumagin Islands region. It was followed by about 6,000 aftershocks including a magnitude 7.6 event on October 19. Other active spots include the 2018 M7.1 Anchorage, 2018 M6.4 Kaktovik, 2018 M7.9 Offshore Kodiak aftershock sequences, Purcell Mountains earthquake swarm, and Wright Glacier cluster northeast of Juneau.
    • Response of an asymmetrical five-story building in Fairbanks, Alaska during the November 30, 2018 M7.1 Anchorage, Alaska earthquake

      Celebi, Mehmet; Ruppert, Natalia (2021-02)
      A recently constructed, five-story, asymmetrical steel building on the campus of the University of Alaska, Fairbanks was equipped with a strong-motion array that recorded the M7.1 Anchorage earthquake of November 30, 2018 at an epicentral distance of 408 km. The largest recorded peak accelerations at the basement and top of the building are 0.021g and 0.071g, respectively. The steel building is designed with several bays that utilize K-shaped buckling restrained braces. The building response records allow identification of fundamental periods (frequencies) as 0.73s (1.4 Hz), 0.63s (1.60 Hz), and 0.56s (1.78 Hz) in the NS, EW, and torsional directions, respectively. System identification computations resulted in estimated critical damping percentages as 7.7% and 4.7 % in the NS and EW directions, respectively. At this low-level of shaking, the building is not expected to (and did not) experience observable damage, which is confirmed with very small average drift ratios. This is the first time a seismic response from this structural array has been analyzed.
    • Alaska Earthquakes Poster

      Gardine, Lea; West, Michael; Grassi, Beth (2020-10)
      Alaska is one of the most seismically active places in the world. This poster connects the geographic distribution of earthquakes from the Alaska Earthquake Center catalog with the core concepts that drive Alaska seismicity. Rupture patches, how plate tectonics forms faults throughout Alaska, and how the angle of the sinking Pacific Plate affects earthquake distribution and creates volcanoes are some of the key concepts represented.
    • Preliminary Summary of Barry Arm Seismic Installations

      West, Michael (2020-09-18)
      In September 2020, the Alaska Earthquake Center installed two seismic stations, one webcam, and a repeater in the Barry Arm region of Prince William Sound. This preliminary summary includes descriptions of the instrumentation as well as some very early observations in the data.
    • PEDESTRIAN TRAVEL-TIME MAPS FOR WHITTIER, ALASKA: An anisotropic model to support tsunami evacuation planning

      Gardine, Lea; Nicolsky, Dmitry (2019-05)
      Tsunami-induced pedestrian evacuation for the community of Whittier is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to exit points from the tsunami hazard zone boundary. The pedestrian travel is restricted to the roads only. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards.
    • PEDESTRIAN TRAVEL-TIME MAPS FOR SITKA, ALASKA: An anisotropic model to support tsunami evacuation planning

      Macpherson, Amy; Gardine, Lea; Nicolsky, Dmitry (2020-06)
      Tsunami-induced pedestrian evacuation for Sitka is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to exit points from the tsunami hazard zone. The pedestrian travel is restricted to the roads only. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards.
    • PEDESTRIAN TRAVEL-TIME MAPS FOR PERRYVILLE, ALASKA: An anisotropic model to support tsunami evacuation planning

      Gardine, Lea; Nicolsky, Dmitry (2019-08)
      Tsunami-induced pedestrian evacuation for the community of Perryville is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to exit points located at the tsunami hazard zone boundary. Pedestrian travel-time maps are computed for two cases: i) travel to an existing evacuating shelter and ii) travel to either the evacuation or an alternative shelter. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards.
    • PEDESTRIAN TRAVEL-TIME MAPS FOR CORDOVA, ALASKA: An anisotropic model to support tsunami evacuation planning

      Macpherson, Amy; Gardine, Lea; Nicolsky, Dmitry (2020-06)
      Tsunami-induced pedestrian evacuation for Cordova is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to exit points from the tsunami hazard zone. The pedestrian travel is restricted to the roads only. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards.
    • Maritime Guidance for Distant and Local Source Tsunami Events: Whittier Harbor, Alaska

      Nicolsky, Dmitry; Suleimani, Elena; Gardine, Lea (2020-02-27)
    • Maritime Guidance for Distant and Local Source Tsunami Events: Valdez Harbor, Alaska

      Nicolsky, Dmitry; Suleimani, Elena; Gardine, Lea (2020-02-27)
    • Maritime Guidance for Distant and Local Source Tsunami Events: Seward Harbor, Alaska

      Nicolsky, Dmitry; Suleimani, Elena; Gardine, Lea (2020-02-27)
    • Maritime Guidance for Distant and Local Source Tsunami Events: Seldovia Harbor, Alaska

      Nicolsky, Dmitry; Suleimani, Elena; Gardine, Lea (2020-02-27)
    • Maritime Guidance for Distant and Local Source Tsunami Events: Homer Harbor, Alaska

      Nicolsky, Dmitry; Suleimani, Elena; Gardine, Lea (2020-02-27)
    • Maritime Guidance for Distant and Local Source Tsunami Events: Cordova Harbor, Alaska

      Nicolsky, Dmitry; Suleimani, Elena; Gardine, Lea (2020-02-27)
    • Pedestrian Travel-Time Maps for Unalaska/Dutch Harbor, Alaska: An anisotropic model to support tsunami evacuation planning

      Macpherson, A.E.; Nicolsky, D.J.; Koehler, R.D. (2016-07-18)
      Tsunami-induced pedestrian evacuation for the community of Unalaska/Dutch Harbor is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on pathdistance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to the tsunami hazard zone boundary and to predetermined assembly areas. Pedestrian travel-time maps are computed for two cases: for travel across all viable terrain or by roads only. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards. This report was funded by the National Tsunami Hazard Mitigation Program grant to the Alaska Division of Homeland Security and Emergency Management and University of Alaska Fairbanks from the Department of Commerce/National Oceanic at Atmospheric Administration (NOAA). This does not constitute an endorsement by Alaska Earthquake Center (AEC) or NOAA.
    • Pedestrian Travel-Time Maps for King Cove, Alaska: An anisotropic model to support tsunami evacuation planning

      Macpherson, A.E.; Nicolsky, D.J.; Koehler, R.D. (2016-07-18)
      Tsunami-induced pedestrian evacuation for the community of King Cove is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The applied method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to the tsunami hazard zone boundary and to predetermined assembly areas. The pedestrian travel-time maps are computed for two cases: for travel across all viable terrain or by roads only. Results presented here are intended to provide guidance to local emergency management agencies for tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards. This report was funded by the National Tsunami Hazard Mitigation Program grant to the Alaska Division of Homeland Security and Emergency Management and University of Alaska Fairbanks from the Department of Commerce/National Oceanic at Atmospheric Administration (NOAA). This does not constitute an endorsement by Alaska Earthquake Center (AEC) or NOAA.
    • Pedestrian Travel-Time Maps for Homer, Alaska: An anisotropic model to support tsunami evacuation planning

      Macpherson, A.E.; Nicolsky, D.J.; Koehler, R.D. (2016-07-18)
      Tsunami-induced pedestrian evacuation for the community of Homer is evaluated using an anisotropic modeling approach developed by the U.S. Geological Survey. The method is based on path-distance algorithms and accounts for variations in land cover and directionality in the slope of terrain. We model evacuation of pedestrians to the tsunami hazard zone boundary and to predetermined assembly areas. The pedestrian travel-time maps are computed for two cases: for travel across all variable terrain or by roads only. Results presented here are intended to provide guidance to local emergency management agencies in tsunami inundation assessment, evacuation planning, and public education to mitigate future tsunami hazards. This report was funded by the National Tsunami Hazard Mitigation Program grant to the Alaska Division of Homeland Security and Emergency Management and University of Alaska Fairbanks from the Department of Commerce/National Oceanic at Atmospheric Administration (NOAA). This does not constitute an endorsement by Alaska Earthquake Center (AEC) or NOAA.