1984 Northern Sumatra earthquake

Earthquake in Indonesia 1984 Northern Sumatra earthquake 1984-11-17 06:49:30 usp000294z 539292 17 November 1984 13:49 Indonesia Sumatra Quake epicentre 7.2 w y 33 km mi 0 0.20 N 98.03 E inline,title Megathrust Sunda megathrust Indonesia VII 1 injured 1984 Northern Sumatra earthquake.jpg USGS ShakeMap The 1984 Northern Sumatra earthquake occurred with a moment magnitude of 7.2 on November 17 at 06:49 UTC. The epicentre was located off the coast of Sumatra, near the island of Nias, where building damage was reported. This earthquake could be strongly felt in parts of Northern Sumatra, including Padang and Medan. The focal mechanism corresponded to reverse faulting.Significant Earthquakes of the World 1984 2010 United States Geological Survey https://earthquake.usgs.gov/earthquakes/eqarchives/significant/sig_1984.php https://web.archive.org/web/20091204220629/https://earthquake.usgs.gov/earthquakes/eqarchives/significant/sig_1984.php dead 2009-12-04Rivera L. Sieh K. Helmberger D. Natawidjaja D. Danny Hilman Natawidjaja amp A Comparative Study of the Sumatran Subduction-Zone Earthquakes of 1935 and 1984 Bulletin of the Seismological Society of America 92 5 2002 1721–1736 http://www.tectonics.caltech.edu/sumatra/downloads/papers/P02a.pdf 10.1785/0120010106 2002BuSSA..92.1721R Tectonic setting The island of Sumatra lies on the convergent plate boundary between the Indo-Australian plate and the Eurasian plate. The convergence between these plates is highly oblique near Sumatra, with the displacement being accommodated by near pure dip-slip faulting along the subduction zone, known as the Sunda megathrust, and near pure strike-slip faulting along the Great Sumatran fault. The major slip events on the subduction zone interface are typically of megathrust type. Historically, megathrust earthquakes have been recorded in 1797, 1833, 1861, 2004, 2005 and 2007, most of them being associated with devastating tsunamis. Smaller (but still large) megathrust events have also occurred in the small gaps between the areas that slip during the larger events, in 1935, 1984, 2000 and 2002.Natawidjaja D. H. Sieh K. Kerry Sieh Chlieh M. Galetzka J. Suwargadi B.W. Cheng H. Edwards R.L. Avouac J.-P. Ward S. N. amp 2006 Journal of Geophysical Research Source parameters of the great Sumatran megathrust earthquakes of 1797 and 1833 inferred from coral microatolls 111 B06403 B06403 https://authors.library.caltech.edu/20847/ 2006JGRB..111.6403N 10.1029/2005JB004025 10220/8480 free The deformation velocity in the offshore Sumatra fore-arc region is estimated to be 19 mm/yr along N45° near the equator, with compression being the dominant deformation.Seismically active deformation in the Sumatra–Java trench-arc region: geodynamic implications http://www.iisc.ernet.in/currsci/mar102006/690.pdf S. Lasitha M. Radhakrishna T. D. Sanu 2006 Current Science 90 6 690–696 The 1984 earthquake occurred in the same gap as the 1935 event. Characteristics The earthquake was caused by a rupture of the subduction interface. The focal depth was about 27 km and the fault plane dipped at 12°. This earthquake contained mainly a down-dip convergence but also a right-lateral displacement. See also List of earthquakes in Indonesia References M 7.1 – Nias region, Indonesia https://earthquake.usgs.gov/earthquakes/eventpage/usp000294z#executive United States Geological Survey External links 539292 Category:Earthquakes in Indonesia Category:Earthquakes in Sumatra Northern Sumatra Earthquake, 1984 Category:November 1984 in Asia Category:1984 disasters in Indonesia Category:November 1984 in Indonesia