1987 Edgecumbe earthquake

Earthquake in New Zealand October 2024 September 2024 1987 Edgecumbe earthquake 1987-03-02 01:42:34 usp00032x6 470420 2 March 1987 1:42 pm NZDT (UTC+13) Bay of Plenty Earthquake, 1987 (16552659081).jpg New Zealand 6.5 w y 8 km mi 0 en-UK 37.88 S 176.84 E inline,title Normal New Zealand None 10M 6.5 – 6 km WNW of Edgecumbe, New Zealand https://earthquake.usgs.gov/earthquakes/eventpage/usp00032x6/executive United States Geological Survey–ANSS 22 August 2021 0.33 g 1 dead (indirect), 25 injured 1987 Edgecumbe earthquake.jpg The 1987 Edgecumbe earthquake measured 6.5 on the moment magnitude scale and struck the Bay of Plenty region of New Zealand at 1.42 pm on 2 March.M 6.5, Edgecumbe, 2 March 1987 http://info.geonet.org.nz/display/quake/M+6.5,+Edgecumbe,+2+March+1987 GeoNet 8 April 2017 The hypocentre was at a shallow depth of 8 km. The epicentre was 2.24 km mi south-south-east of the town of Matatā, and 15 km mi north-north-west of Edgecumbe, on the Rangitaiki Plains (the floodplain of the Rangitaiki River, the Tarawera River and the Whakatāne River). It was the most damaging earthquake New Zealand had experienced since the 1968 Inangahua earthquake. Main event The main shock was preceded for two weeks by earthquake swarms in two areas of the Bay of Plenty. A swarm started on 21 February off-shore from Maketu, near Te Puke, 40 kilometres from the main shock's epicentre, and another swarm started on 26 February between Matatā and Thornton, very close to the epicentre.Smith Euan G.C. Oppenheimer Clive M.M. 1989 The Edgecumbe earthquake sequence: 1987 February 21 to March 18 New Zealand Journal of Geology and Geophysics 32 1 31–42 10.1080/00288306.1989.10421386 1989NZJGG..32...31S free Then there was a 5.2 l y earthquake at 1.35 pm on 2 March, followed by the main shock seven minutes later. The main shock appears to have actually consisted of two ruptures, and possibly a third. There were indications that the first rupture propagated towards the south-west, triggering a second rupture 9 kilometres to the south-west and three seconds after the first. There is also the possibility of a third, significantly smaller, rupture another ten seconds later.Anderson Helen Webb Terry 1989 The rupture process of the 1987 Edgecumbe earthquake, New Zealand New Zealand Journal of Geology and Geophysics 32 1 43–52 10.1080/00288306.1989.10421387 1989NZJGG..32...43A free The largest aftershock measured 5.6 and struck nine minutes later at 1.51 pm.Staff, New Zealand Department of Scientific and Industrial Research The March 2, 1987, earthquake near Edgecumbe, North Island, New Zealand Eos 1987 68 44 1162–1171 1987EOSTr..68.1162S 10.1029/EO068i044p01162 M.J. Pender T.W. Robertson 1987 Edgecombe sic earthquake: reconnaissance report http://www.nzsee.org.nz/db/Bulletin/Archive/20(3)0201.pdf Bulletin of the New Zealand National Society for Earthquake Engineering 20 3 201–49 7 April 2017 Eleven ground-surface ruptures occurred in the Rangitaiki Plains, though no active faults had previously been recognised on the Plains. The largest rupture, the Edgecumbe Fault, was 7 km mi long and formed on, and extended, a late Holocene fault scarp. The old scarp had previously been unrecognised, but was later seen in aerial photographs taken before the earthquake. The northern end of the scarp is one kilometre east of Edgecumbe, and the scarp runs southwest to a point three kilometres north of Te Teko. The land on the north-western side dropped by up to 2.1 m ft, and that area is now more prone to flooding. The most spectacular feature of the scarp was a deep prominent fissure up to 3 metres wide and 3–4 metres deep, mostly with near-vertical walls, that opened up along the fault. It appears that the fault has ruptured at least once previously in the past 1800 years.Franks C.A.M. Beetham R.D. Salt G.A. 1989 Ground damage and seismic response resulting from the 1987 Edgecumbe earthquake, New Zealand New Zealand Journal of Geology and Geophysics 32 1 135–44 10.1080/00288306.1989.10421397 1989NZJGG..32..135F free The intense ground shaking led to a large number of ground surface failures, including sand boils, ridge-top shatters and debris avalanches on steeper slopes. Franks C.A.M. 1988 Engineering geological aspects of the Edgecumbe, New Zealand earthquake of 2 March 1987 Quarterly Journal of Engineering Geology 21 4 337–345 10.1144/GSL.QJEG.1988.021.04.06 128753378 The Rangitaiki Plains is part of the Whakatāne Graben and both lie within the Taupō Volcanic Zone, which is widening and subsiding. During the Edgecumbe earthquake, the area widened by 1.2 metres http://info.geonet.org.nz/display/quake/2017/03/02/1987+Edgecumbe+Earthquake%3A+30+years+ago+today 1987 Edgecumbe Earthquake: 30 years ago today 2 March 2017 GeoNet 9 April 2017 and dropped in height by 2 m on.Beanland S Blick GH Darby DJ Normal faulting in a back arc basin: geological and geodetic characteristics of the 1987 Edgecumbe earthquake, New Zealand Journal of Geophysical Research: Solid Earth 1990 10 95(B4) 4693–707 10.1029/JB095iB04p04693 1990JGR....95.4693B The most damage was in the towns of Edgecumbe, Te Teko, Kawerau, Matatā and Thornton, where chimneys toppled and poorly constructed houses were seriously damaged. The hardest hit was Edgecumbe, with damage to approximately 50% of its houses. There was extensive damage to its milk factory, with large storage tanks toppled. Railway tracks in the town were bent and buckled, and an 80-tonne New Zealand Railways DC class locomotive toppled over. Twenty-five people suffered injuries that needed medical attention, but no-one was killed. http://www.teara.govt.nz/en/historic-earthquakes/page-11 Eileen McSaveney Historic earthquakes – The 1987 Edgecumbe earthquake Te Ara – the Encyclopedia of New Zealand 16 November 2016 7 April 2017 The foreshock seven minutes before the main shock had cut the power supply, and many people had moved away from heavy machinery and out of buildings that then collapsed in the main earthquake. Gallery See also New Zealand List of earthquakes in New Zealand References The Geology of Earthquakes R. S. Yeats K. E. Sieh Kerry Sieh C. R. Allen Clarence Allen (geologist) 1997 978-0-19-507827-5 Oxford University Press 273–275 External links 470420 Category:History of the Bay of Plenty Region 1987 Edgecumbe Edgecumbe Category:March 1987 in Oceania Category:1987 disasters in New Zealand Category:Whakatane Graben