1871 Lānaʻi earthquake

Earthquake in the Hawaiian Islands 1871 Lānaʻi earthquake 19 February 1871 Yes 20.7 -156.0 type:event_region:US-HI inline, titleM 6.8 – Maui region, Hawaii https://earthquake.usgs.gov/earthquakes/eventpage/official18710220084500000/executive United States Geological Survey 12 February 2022 5 November 2019 Hawaii 1871-02-20 08:45:00 official18710220084500000 22:11 HST 7.5 w yes Unknown Hawaii yes Moderate 8 – 11 Uncertain Yes An earthquake struck near the Hawaiian island of Lanai on February 19, 1871, at 10:11 pm HST with an estimated magnitude of 7.5 on the moment magnitude scale (w). It remains one of the largest seismic events to hit the Hawaiian Islands since the 1868 Kaʻū earthquake, with its effects being felt throughout the entire archipelago. It caused severe damage on the islands of Lanai, Molokai and Maui.Carl W. Stover https://books.google.com/books?id=bY0KAQAAIAAJ&q=Seismicity+of+the+United+States%2C+1568-1989+%28revised%29 Seismicity of the United States, 1568-1989 (revised) Jerry L. Coffman United States Government Printing Office Washington DC 1993 A tsunami may have been generated however there are speculations if it had actually happened. Despite the size of the quake and the extent of damage, there were no deaths. Tectonic setting The Hawaiian Islands are situated in the middle of the Pacific plate, far from any known plate boundary, where most of the world's earthquakes occur. This island chain is a product of hotspot volcanism where magma is able to make its way up to the crust and onto the surface, creating volcanoes. Hawaiʻi is the youngest volcanic island and marks where the hotspot is currently located. Earthquake Modelling of an earthquake along a fault with a dimension of 73 km by 41 km and an average slip of 1.7 m corresponds to a moment magnitude (w) of 7.5. The estimated w 7.5 earthquake is the third-largest to occur in the Kingdom of Hawaii, behind the 1868 and 1975 events. It is also the largest to occur northwest of the Hawaii (Big Island). Previous studies estimated the magnitude to be ~7.0 and based on felt reports, I 6.8. The most likely source of this event is the Molokai fracture zone, a structure in the Pacific Ocean seafloor that separates 85 million-year-old and 100 million-year-old oceanic lithosphere. It runs through the island chain near Lanai and Maui. Along this part of the fracture zone, stress due to the weight of the Hawaiian Islands may have resulted in slippage along with the structure. Faulting likely occurred at a deep depth, in the lower oceanic lithosphere basement and mantle. The same seismic zone is suspected to have produced an w 6.8 earthquake in 1938 near Maui.Butler Rhett 2020 The 1871 Lāna'i Earthquake in the Hawaiian Islands Seismological Research Letters 91 6 3612–3621 10.1785/0220200220 2020SeiRL..91.3612B 225312714 https://www.higp.hawaii.edu/~rhett/PDFs/Butler_SRL_2020_The_1871_Lanai_Earthquake_in_the_Hawaiian_Islands.pdf Tsunami A tsunami was thought to have accompanied the earthquake shortly after, as mentioned in several local newspapers and reports.Doak C. Cox https://books.google.com/books?id=AJUSAQAAIAAJ&q=1871+Lanai+earthquake&pg=RA1-PA32 Local tsunamis and possible local tsunamis in Hawaii Joseph Morgan University of Hawaii 1977 United States 32–33 This claim however, is doubtful as documentations were vague and other eyewitnesses along the shores did not witness any large waves.Tsunami Event Information HAWAII https://www.ngdc.noaa.gov/hazel/view/hazards/tsunami/event-more-info/1019 live https://web.archive.org/web/20210201101817/https://www.ngdc.noaa.gov/hazel/view/hazards/tsunami/event-more-info/1019 2021-02-01 27 January 2021 NGDC Impact MMI by locationMMILocationsVIII–11Maui, Lanai, MolokaiVII–VIOahu, Hawaiʻi,5–IVKauai, Niihau Lanai The earthquake reportedly lasted 55 seconds to a minute with shaking directed in a northeast–southwest motion. The most extreme shaking was felt on the islands of Maui and Lanai where the values on the Mercalli intensity scale ranged from VIII–XI (Severe–Extreme). There, fractures formed along the slopes, and rocks that broke off from peaks collapsed. Between Manele Bay and Kamaiki Point, Pali Kaholo; a well-known cliff collapsed into the ocean. Shaking on the island was stronger than during the 1868 earthquake. Maui In Lahaina, almost every adobe and brick building was destroyed.Cox Doak C. 1985 The Lanai Earthquake of February 1871 http://hdl.handle.net/10125/18212 Environmental Center Special Reports Environmental Center, University of Hawaii at Manoa 10125/18212 A mission church sustained cracks in its walls. The courthouse and a stone building were also damaged. It was reported that every fence and wall fell towards the north. At the pier, a crack 14.6 meters long appeared. Oahu In Oahu, the earthquake cracked walls and split two houses. In Ewa, the belfry of a Catholic church supported by cast-iron pillars was completely destroyed. In Waianae, ground fissures and land slumps were widely reported.Charles H. Fletcher III Charles H. Fletcher III Eric E. Grossman Bruce M. Richmond Ann E. Gibbs 2002 Atlas of Natural Hazards in the Hawaiian Coastal Zone https://pubs.usgs.gov/imap/i2761/sections/1_Intro.pdf live https://web.archive.org/web/20050523104145/http://pubs.usgs.gov:80/imap/i2761/sections/1_Intro.pdf 2005-05-23 27 January 2021 United States Geological Survey Some landslides and rockfalls resulted in road blockage. Plasters on homes, offices, and a courthouse fell down in Honolulu. In addition, chimneys at the Punahou School in Honolulu were also knocked off. On the Mercalli intensity scale, the earthquake's intensity was likely VI (Strong), and it lasted some 30–45 seconds. The quake caused panic and hysteria, some residents fainted while others began praying. Some residents reported feeling nauseated and started to vomit. Overall, damage in Oahu was moderate, with some structures compromised and a number of collapses reported. Molokai In Molokai, the earthquake overturned furniture and kitchen items in homes. Stone houses began to crack as the ground shook. Parts of a Catholic church fell to the ground, and plasters came off most buildings in the area.Cook T. E. 4 March 1872 The Earthquake on Molokai The Honolulu Advertiser https://chroniclingamerica.loc.gov/lccn/sn82015418/1871-03-04/ed-1/seq-3/ 27 January 2021 Ground fissures tore through the landscape, breaking roads. The severity of shaking corresponded towards VIII–IX (Severe–Violent). North-central Molokai felt weaker intensities of VI–VII (Strong–Very strong). Hawaii A direct observer wrote in a letter stating that the shaking was "as severe as" the 1868 earthquake. The sound of roaring was heard during the quake, which was described as having a great intensity and weakening, ending with an extremely violent shock before the shaking had stopped. Stone walls everywhere toppled in Kawaihae. See also List of earthquakes in Hawaii List of earthquakes in the United States References Category:February 1871 in Oceania Category:1871 in Hawaii Category:1871 earthquakes Category:Earthquakes in Hawaii Category:Tsunamis in the United States Category:Natural disasters in Hawaii