Microfossil evidence for land movements associated with the AD 1964 Alaska earthquake

Zong, Y.; Shennan, I.; Combellick, R.A.; Hamilton, S.L.; Rutherford, M.M.

Abstract

Microfossil diatom and pollen data from a number of cores at coastal marshes at Girdwood Flats and Kenai Flats in Cook Inlet, Alaska, suggest that there was a phase of gradual land subsidence prior to the main shock of the AD 1964 earthquake. This phase followed a long period of gradual land uplift since the last large earthquake, which occurred about 730-900 years ago. Caesium (137Cs) records indicate that subsidence started approximately 15 years before the 1964 earthquake. This pre-seismic subsidence is evident in the coastal marsh sediment sequences in changes in diatom and pollen assemblages that indicate changes in tidal-marsh environments or a change from raised-bog to marsh conditions. The microfossil evidence indicates ~0.15 m pre-seismic land subsidence at both Girdwood Flats and Kenai Flats and co-seismic subsidence of ~1.8 m and ~0.2 m respectively.

Citation

Zong, Y., Shennan, I., Combellick, R., Hamilton, S., & Rutherford, M. (2003). Microfossil evidence for land movements associated with the AD 1964 Alaska earthquake. Holocene, 13(1), 7-20. https://doi.org/10.1191/0959683603hl590rp

• Journal Article Type: Article
• Publication Date: 2003-01
• Deposit Date: Nov 17, 2006
• Journal: Holocene
• Print ISSN: 0959-6836
• Electronic ISSN: 1477-0911
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 1
• Pages: 7-20
• DOI: https://doi.org/10.1191/0959683603hl590rp
• Keywords: Diatom, Pollen, Earthquake, 1964, Pre-Seismic, Land Subsidence, Alaska.