1973 Nemuro earthquake: Difference between revisions

==Aftershocks==

Seven days after the mainshock, a magnitude ({{M|s}}) 7.1 earthquake struck west of the Nemuro Peninsula at a depth of 50 km.<ref name="M 7.1" /> It had a maximum Mercalli intensity of VIII or a JMA intensity of 5, lasting for less than a minute. In the community of Goryachiy Plyazh and Golovnino on Kunashir Island, it was felt stronger than the mainshock. Some frightened residents jumped from the windows of their homes. One person was injured and some minor damage was reported in Kushiro, Hokkaidō.<ref>{{cite web|title=Significant Earthquake: RUSSIA: KURIL ISLANDS| url=https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/4639|publisher=[[National Geophysical Data Center]]| accessdate=May 9, 2021 |date=June 24, 1973}}</ref>

 

The '''1975 Kuril Islands earthquake''' which struck on June 10, nearly two years after the 1973 event was also considered an aftershock.<ref name="Yoshio">{{cite journal |last1=Yoshio |first1=Fukao |title=Tsunami earthquakes and subduction processes near deep-sea trenches |journal=JOURNAL OF GEOPHYSICAL RESEARCH |date=10 May 1979 |volume=84 |issue=B5 |pages=2303-2314 |doi=10.1029/JB084iB05p02303 |url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JB084iB05p02303 |access-date=11 June 2021}}</ref> It ruptured the shallow interface of the Kuril Sunduction Zone with a focal depth of 15 km, between the rupture zones of the 1973 and 1969 earthquakes. Although it had a smaller surface wave magnitude and JMA magnitude of 7.1,<ref name="Sapporo">{{cite journal |title=北海道東部沖地震のお知らせ |journal=Sapporo District Meteorological Observatory |date=1976 |trans-title=Report on the Earthquake Off E coast of Hokkaido |language=Japanese}}</ref><ref name="M 7.0">{{cite web |title=M 7.0 - Kuril Islands |url=https://earthquake.usgs.gov/earthquakes/eventpage/usp0000bdp/executive |website=earthquake.usgs.gov |publisher=USGS |access-date=11 June 2021}}</ref> it generated tsunami run-ups higher than the mainshock. Further analysis of event data has enabled the calculation for the moment magnitude and tsunami magnitude of the earthquake. Two studies in 1978 and 1977 calculated the magnitude at {{M|w}} 7.5–7.6 and 7.7 respectively.<ref name="Ioki">{{cite journal |last1=Ioki, K., Tanioka, Y. |title=Rupture Process of the 1969 and 1975 Kurile Earthquakes Estimated from Tsunami Waveform Analyses |journal=Pure and Applied Geophysics |date=2016 |volume=173 |pages=4179–4187 |doi=10.1007/s00024-016-1402-0 |url=https://link.springer.com/article/10.1007/s00024-016-1402-0 |access-date=11 June 2021}}</ref> Estimating the tsunami magnitude of the event using tsunami data places this event at {{M|t}} 7.9. The 1975 aftershock is considered a [[tsunami earthquake]] due to the disproportionately large tsunami that it generated.<ref name="Ioki" />