Intensities and isoseismal map for the St. Elias earthquake of February 28, 1979

Stover, C.W.; Reagor, B.G.; Wetmiller, R J

doi:10.1785/bssa0700051635

Cited by 14 publications

(2 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 28 February 1979 M w 7.5 earthquake occurred in the tectonically complex region containing the Wrangell-St. Elias Mountains. Several studies examined this earthquake in its aftermath (Hasegawa et al, 1980;Lahr et al, 1980;McCann et al, 1980;Perez & Jacob, 1980;Stover et al, 1980). Estabrook et al (1992) revisited the event and concluded: "The locations and source mechanisms of these subevents and locations of aftershocks define a shallow dipping surface at the eastern edge of the Pacific plate."…”

Section: Mainshock Event Selectionmentioning

confidence: 99%

See 1 more Smart Citation

Aftershock Regions of Aleutian‐Alaska Megathrust Earthquakes, 1938–2021

Tape

Lomax²

2022

JGR Solid Earth

View full text Add to dashboard Cite

With five earthquakes (1938, 1946, 1957, 1964, and 1965), the Aleutian‐Alaska subduction plate boundary ruptured a length of 3,548 km. We revisit these five earthquakes—first studied in detail by Sykes (1971, https://doi.org/10.1029/JB076i032p08021)—through probabilistic relocation of carefully selected mainshocks and aftershocks. Our final catalog of 324 events is established from a set of 12 mainshocks that includes all Mw ≥ 7.7 megathrust earthquakes. Using the relocated catalog, we create revised aftershock regions delimited both parallel and normal to the trench. These aftershock regions exhibit significant differences from previous studies, with the following basic findings: the 10 November 1938 Mw 8.3 earthquake extended further west, to the Shumagin Islands, and further east, into the Kodiak region, relative to the prevailing aftershock region established by McCann et al. (1979, https://doi.org/10.1007/978-3-0348-6430-5_2). The 01 April 1946 Mw 8.6 sequence was anomalously concentrated near the trench, which implies near‐trench coseismic slip that contributed to the exceptionally large tsunami. The 09 March 1957 Mw 8.6 aftershocks spanned a 1,230 km length with numerous aftershocks within the outer‐rise region of the incoming Pacific plate. The 28 March 1964 Mw 9.2 aftershocks extended east into the Pamplona thrust system (south of Icy Bay, Alaska), suggesting coseismic rupture into this region; this is consistent with coseismic static displacements, as well as current estimates of interseismic locking. The post‐1965 events we examine are all smaller than the earlier events, but since they occurred in an era of improved data collection (seismic, geodetic, and tsunami), they provide a better opportunity for assessing the link between the distribution of aftershocks and the occurrence of coseismic, postseismic, and interseismic slip.

show abstract

Section: Mainshock Event Selectionmentioning

confidence: 99%

“…Elias Mountains. Several studies examined this earthquake in its aftermath (Hasegawa et al., 1980; Lahr et al., 1980; McCann et al., 1980; Perez & Jacob, 1980; Stover et al., 1980). Estabrook et al.…”

Section: Event Selectionmentioning

confidence: 99%