1965 Rat Islands earthquake

Megathrust earthquake in the Aleutian Islands October 2026 1965 Rat Islands earthquake 1965-02-04 05:01:22 859206 iscgem859206 1965 02 03 19:01:22 $10,000 Alaska 8.7 w y 30.3 km mi 0 on 51.29 178.55 inline,title United States (Alaska) 10.7 m on 6 1965 Rat Islands earthquake.jpg USGS ShakeMap The 1965 Rat Islands earthquake occurred at 05:01 UTC, on 4 February (19:01, 3 February local time). It had a magnitude of 8.7, making it one of the largest earthquakes in recorded history, and triggered a tsunami of over 10 m on Shemya Island,https://earthquake.usgs.gov/earthquakes/states/events/1965_02_04.php Historic Earthquakes Rat Islands, Alaska United States Geological Survey 26 October 2009 8 March 2010 dead https://web.archive.org/web/20100116161303/http://earthquake.usgs.gov/earthquakes/states/events/1965_02_04.php 16 January 2010 but caused very little damage. Tectonic setting The Rat Islands form part of the Aleutian Islands, a chain of volcanic islands forming an island arc, that results from the subduction of the Pacific plate beneath the North American plate. This plate boundary, the Aleutian Trench, has been the location of many megathrust earthquakes. Characteristics thumb|260 px|Map showing the tectonics and seismicity of Alaska The 1965 Rat Islands earthquake share common features with the 1963 Kuril Islands earthquake and the 1964 Alaska earthquake.Wu Francis T. Kanamori Hiroo Hiroo Kanamori Source mechanism of February 4, 1965, Rat Island earthquake Journal of Geophysical Research 9 October 1973 78 26 6082–6092 10.1029/jb078i026p06082 1973JGR....78.6082W https://resolver.caltech.edu/CaltechAUTHORS:20150810-161941909 Earthquake The earthquake was associated with a 600 km long rupture along the plate boundary, based on the distribution of aftershocks.Beck Susan L. Susan L. Beck Christensen Douglas H. Rupture process of the February 4, 1965, Rat Islands Earthquake Journal of Geophysical Research 1991 96 B2 2205 10.1029/90JB02092 1991JGR....96.2205B https://zenodo.org/record/1231303 The pattern of energy release suggest the presence of three asperities along the plate interface, each causing a pulse of moment release. Modelling of the tsunami supports the idea that the earthquake consisted of three sub-events, related to three structural 'blocks' within the overriding plate.10.1016/S0065-2687(08)60275-7 Heterogeneous Coupling Along Alaska-Aleutians as Inferred from Tsunami, Seismic, and Geodetic Inversions Tsunamigenic Earthquakes and Their Consequences Advances in Geophysics 1998 Johnson Jean M. 39 1–116 978-0-12-018839-0 https://books.google.com/books?id=CZVn6MjyAHMC&pg=PA1 The main shock was followed by an earthquake of magnitude 7.6 nearly two months later, that triggered a small tsunami.NGDC Search result for 1965 Alaska earthquakes http://www.ngdc.noaa.gov/nndc/struts/results?bt_0=1965&st_0=1965&type_17=EXACT&query_17=None+Selected&op_12=eq&v_12=&type_12=Or&query_14=AK&type_3=Like&query_3=&st_1=&bt_2=&st_2=&bt_1=&bt_4=&st_4=&bt_5=&st_5=&bt_6=&st_6=&bt_7=&st_7=&bt_8=&st_8=&bt_9=&st_9=&bt_10=&st_10=&type_11=Exact&query_11=&type_16=Exact&query_16=&display_look=1&t=101650&s=1&submit_all=Search+Database https://web.archive.org/web/20171230172548/https://www.ngdc.noaa.gov/nndc/struts/results?bt_0=1965&st_0=1965&type_17=EXACT&query_17=None+Selected&op_12=eq&v_12=&type_12=Or&query_14=AK&type_3=Like&query_3=&st_1=&bt_2=&st_2=&bt_1=&bt_4=&st_4=&bt_5=&st_5=&bt_6=&st_6=&bt_7=&st_7=&bt_8=&st_8=&bt_9=&st_9=&bt_10=&st_10=&type_11=Exact&query_11=&type_16=Exact&query_16=&display_look=1&t=101650&s=1&submit_all=Search+Database December 30, 2017 8 March 2010 dead This was not an aftershock, but a normal fault event within the outer rise of the subducting plate, triggered by the earlier event.Abe Katsuyuki Lithospheric normal faulting beneath the Aleutian trench Physics of the Earth and Planetary Interiors January 1972 5 190–198 10.1016/0031-9201(72)90091-X 1972PEPI....5..190A Tsunami The tsunami had a maximum run-up height of 10.7 m on Shemya Island, 2.0 m at Amchitka Island, 1.6 m at Attu Island and 1.1 m in northern Kauai, Hawaii. It was also observed in Peru, Ecuador, Mexico, California, Japan and eastern Russia. Damage Flooding from the tsunami caused $10,000 worth of damage on Amchitka Island. Minor damage from the earthquake was recorded on both Attu and Shemya islands in the form of cracks in runways. See also 2021 Chignik earthquake List of earthquakes in 1965 List of earthquakes in Alaska List of earthquakes in the United States References Further reading Jordan James N. Lander James F. Black Rudolph A. Aftershocks of the 4 February 1965 Rat Island Earthquake Science 1965 148 3675 1323–1325 10.1126/science.148.3675.1323 1716000 17791261 1965Sci...148.1323J 11528694 External links 859206 Category:1965 in Alaska Category:February 1965 Category:Megathrust earthquakes in Alaska Rat Islands Category:1960s tsunamis Category:Rat Islands 1965