1797 Riobamba earthquake

Deadly earthquake in central Ecuador 11 1797 Riobamba earthquake yes 4 February 1797 07:30 Ecuador -1.6 -78.6 Bullseye1.png 50 top Riobamba -1.675 -78.65 10 left Quito -0.25 -78.58 10 left 250 right yes 7.6 w y8.3 L yes -1.6 -78.6 inline,title Ecuador 6,000–40,000 The 1797 Riobamba earthquake occurred at 12:30 UTC on 4 February. It devastated the city of Riobamba and many other cities in the Interandean valley, causing between 6,000 and 40,000 casualties. It is estimated that seismic intensities in the epicentral area reached at least XI (Extreme) on the Mercalli intensity scale, and that the earthquake had a magnitude of 7.6–8.3,Céline Beauval Hugo Yepes William H. Bakun José Egred Alexandra Alvarado Juan-Carlos Singaucho Locations and magnitudes of historical earthquakes in the Sierra of Ecuador (1587–1996) Geophysical Journal International 2010 131 3 1613–1633 10.1111/j.1365-246X.2010.04569.x 2010GeoJI.181.1613B 4617325 free National Geophysical Data Center / World Data Service (NGDC/WDS): NCEI/WDS Global Significant Earthquake Database. NOAA National Centers for Environmental Information Significant Earthquake Information 1972 NOAA National Centers for Environmental Information https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/1537 20 August 2010 10.7289/V5TD9V7K the most powerful historical event known in Ecuador.http://www.apat.gov.it/site/_Files/Abstracts_Como.pdf Seismic Hazard Assessment for Guayaquil City (Ecuador): Insights from Quaternary Geological Data Chunga K. 22 August 2010 https://web.archive.org/web/20110717122543/http://www.apat.gov.it/site/_Files/Abstracts_Como.pdf 2011-07-17 dead The earthquake was studied by Prussian geographer Alexander von Humboldt, when he visited the area in 1801–1802.Lavilla E.O. 2004 Under the Southern Cross: Stories around Humboldt and Bonpland's trip to the New Continent Latin American Applied Research 34 203–208 http://www.scielo.org.ar/pdf/laar/v34n4/v34n4a01.pdf 22 August 2010 Tectonic setting The active tectonics of Ecuador is dominated by the effects of the subduction of the Nazca plate beneath the South American plate. The main NNE-SSW trending fault systems show a mixture of dextral (right lateral) strike-slip faulting and reverse faulting. In addition to these faults that run parallel to the Andes in Ecuador, there are two important SW-NE trending-dextral-fault systems: the Pallatanga fault and the Chingual fault.https://pubs.usgs.gov/of/2003/ofr-03-289/OFR-03-289-text.pdf Database and Map of Quaternary faults and folds of Ecuador and its offshore regions Eguez A. Alvarado A. Yepes H. Machette M.N. Costa C. Dart R.L. amp USGS Open-File Report 03-289 2–3 22 August 2010 The Pallatanga fault runs close to the epicenter and movement on this fault has been suggested as the cause of the earthquake, although there is no clear surface break supporting such recent movement.Winter T. Avouac J-P. Lavenu A. amp 1993 Late Quaternary kinematics of the Pallatanga strike-slip fault (Central Ecuador) from topographic measurements of displaced morphological features Geophysical Journal International 115 3 905–920 1993GeoJI.115..905W 10.1111/j.1365-246X.1993.tb01500.x free Damage The area of significant damage (Intensity ≥VII) extended from Quito in the north to more than 60 km south of Riobamba, including the cities of Guaranda, Ambato, Latacunga and the towns of Saquisilí and Baños. Riobamba and the town of Quero were both destroyed by landslides. The Pastaza River was dammed for up to eighty days by landslides at the foot of the Tungurahua volcano.Lyell Charles Charles Lyell Principles of Geology http://www.esp.org/books/lyell/principles/facsimile/contents/lyell-v1-ch23.pdf 1st 1830 John Murray 410 XXIII 22 August 2010 Humboldt visited then region several years after the earthquake, and his analysis therefore largely relied on anecdotal accounts that he gathered. Some of the observations such as "the bodies of many of the inhabitants were found to have been hurled to Cullca, a hill several hundred feet in height and on the opposite side of the river Lican", are not credible.Wood H.O. Harry O. Wood 1911 The observation of earthquakes: A guide for the general observer Bulletin of the Seismological Society of America 1 2 65–67 10.1785/BSSA0010020048 http://content.cdlib.org/view?docId=hb9z09p466;NAAN=13030&doc.view=frames&chunk.id=div00005&toc.depth=1&toc.id=div00005&brand=calisphere 22 August 2010 subscription He gave a figure of thirty to forty thousand for the number of casualties,https://books.google.com/books?id=p6o-AQAAMAAJ&pg=PA30 Personal Narrative of Travels to the Equinoctial Regions of the New Continent: During the Years 1799–1804 Humboldt Alexander von Bonpland Aimé Longman 1819 5 30–31 while some more recent estimates give figures ranging from six to twelve thousand.http://iisee.kenken.go.jp/utsu/utsuweq_bak_eng.html Catalog of Damaging Earthquakes in the World – Search parameters IISEE 25 December 2008 22 August 2010 https://archive.org/details/ecuadoritsancie00enocgoog riobamba%20earthquake%201797%20casualties. Ecuador: Its Ancient and Modern History, Topography and Natural Resources, Industries and Social Development Enock Charles Reginald T.F.Unwin, Limited 1914 16610.1016/j.geomorph.2014.02.030 Paleoseismology and tectonic geomorphology of the Pallatanga fault (Central Ecuador), a major structure of the South-American crust Geomorphology 237 14–28 2015 Baize Stéphane Audin Laurence Winter Thierry Alvarado Alexandra Pilatasig Moreno Luis Taipe Mercedes Reyes Pedro Kauffmann Paul Yepes Hugo 2015Geomo.237...14B 2 http://www.documentation.ird.fr/hor/fdi:010064630 subscription Characteristics The shaking lasted for three to four minutes.Amodio E. 2005 Las furias del temblor. Análisis comparativo de dos sismos históricos: Quito, febrero 1797 y Cumaná, diciembre 1797 Revista Geográfica Venezolana 119–141 http://www.saber.ula.ve/bitstream/123456789/24668/2/articulo7.pdf 20 August 2010 Spanish The estimated rupture length for the earthquake is 70.3 km, with a fault azimuth of 067°.Giesecke A. Capera A.A.G. Leschiutta I. Migliorini E. Valverde L.R. amp 2004 The CERESIS earthquake catalogue and database of the Andean Region: background, characteristics and examples of use Annals of Geophysics 47 2/3 421–435 http://www.earth-prints.org/bitstream/2122/769/1/07Giesecke.pdf 22 August 2010 A moment magnitude of 7.6 was estimated based on data about the intensity distribution of the earthquake. An earthquake of this size would imply a rupture length of about 110 km, which can only be achieved along the Pallatanga Fault System. Aftermath The city of Riobamba was rebuilt nearly 20 km northeast of its original site, now occupied by the small town of Cajabamba.Kunstaetter R. Kunstaetter D. Footprint Ecuador and Galápagos https://books.google.com/books?id=ZMSTiPf6tnQC&pg=PA244 20 August 2010 6th 2007 Footprint Travel Guides 978-1-904777-93-9 244 See also Ecuador List of earthquakes in Ecuador List of historical earthquakes References Category:Earthquakes in Ecuador Category:1790s earthquakes Category:1797 disasters Category:February 1797 Category:18th century in Ecuador Category:1797 in South America Category:1797 in the Spanish Empire Category:18th century in the Viceroyalty of New Granada Category:18th-century disasters in South America