• 2021 Alaska Seismicity Summary

      Ruppert, Natalia; Gardine, Lea (2022-02-23)
      The Alaska Earthquake Center reported 49,120 seismic events in Alaska and neighboring regions in 2021. The largest earthquake was a magnitude 8.2 event that occurred on July 29 southwest of Kodiak Island. It was followed by about 1,300 aftershocks including two magnitude 6.9 events on August 14 and October 11. Other active spots include sequences near Harding Lake in Interior Alaska in July-September and near Yakutat Bay in September. The largest earthquake in mainland Alaska was the M6.1 Chickaloon Earthquake on May 31. We continued to monitor ongoing activity within the 2018 M7.1 Anchorage, 2018 M6.4 Kaktovik, and 2018 M7.9 Offshore Kodiak aftershock sequences, the Purcell Mountains earthquake swarm, and the Wright Glacier cluster northeast of Juneau.
    • AACSE earthquake catalog: May-December, 2018

      Ruppert, Natalia A.; Barcheck, Grace; Abers, Geoffrey A. (2021-02)
      The Alaska Amphibious Community Seismic Experiment (AACSE) comprised 75 ocean bottom seismometers and 30 land stations and covered about 650 km along the segment of the subduction zone that includes Kodiak Island, the Alaska Peninsula and the Shumagin Islands between May, 2018 and September, 2019 (Barcheck et al., 2020). This unprecedented dataset has the potential to support a greatly enhanced earthquake catalog by both increasing the number of detected earthquakes and improving the accuracy of their source parameters. We use all available regional and AACSE campaign seismic data to compile an enhanced earthquake catalog for the region between Kodiak and Shumagin Islands including Alaska Peninsula (51-59N, 148-163W). We apply the same processing and reporting standards to additional picks and seismic events as the Alaska Earthquake Center currently use for compilation of the authoritative regional earthquake catalog. This release includes earthquake catalogs for the time period between May 12 and December 31, 2018 (3829 events total 1132 of which are newly detected). We include monthly CSS database tables and quakeml files. This material is based upon work supported by the U.S. Geological Survey under Grant No. G20AP00026. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.
    • 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.
    • 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.