1986 João Câmara earthquake

Rare earthquake in northeastern Brazil 1986 João Câmara earthquake 1986-11-30 05:19:48 usp00030gs 482615 Sismo de João Câmara (1986).jpg Destroyed homes following the earthquake File:RioGrandedoNorte_Municip_JoaoCamara.svg Brazil 30 November 1986 02:19:48 Brasilia Standard Time 5.1 w y4.9 b yISC-GEM Global Instrumental Earthquake Catalogue (1900–2012) http://www.isc.ac.uk/iscgem/index.php ISC 2016 International Seismological Centre Version 3.0 15 km mi 0 on -5.41 -35.9 region:IN_type:event inline,title Rio Grande do Norte, Brazil 7Ferreira Takeya Costa Moreira 1987 1042 Strike-slip The 1986 João Câmara earthquake (pt Sismo de João Câmara de 1986) struck on 30 November 1986 at 02:19 Brasília Time with a moment magnitude of 5.1 near the town of João Câmara, in the state of Rio Grande do Norte, Brazil. The event was felt over a large area of northeastern Brazil, including the cities of Natal and Mossoró. It took place in a more seismically active part of Brazil, where deformation of land at the Brasiliano orogeny between the São Francisco and São Luís cratons formed a series of fault zones in between 1 billion to 538.8 million years ago. The 1986 João Câmara earthquake occurred on one of these fault zones while accompanied by a lengthy series of earthquakes which consisted more than 1,000 recorded events. This mainshock was preceded by a series of foreshocks that began in August and was followed by a series of aftershocks which continued until 1990. Widespread damage to buildings at João Câmara occurred and thousands of people were displaced. The earthquake is widely remembered as one of the most significant events in Brazil's history.30 Anos do Terremoto de João Câmara https://labsis.ufrn.br/noticias/20754905/30-anos-do-terremoto-de-joao-camara March 5, 2023 Labsis UFRN pt Tectonic setting Geology of Brazil Brazil is geologically dominated by three major sedimentary basins; the Amazon, Paraná and Parnaíba basins. These basins of Paleozoic-Mesozoic age are the drainage systems of the South American continent. The rest of the country consists of metamorphic rocks of the Brazilian Shield, a geologic province which consists of four cratons of Archean to Mesoproterozoic age. These cratons are connected by Neoproterozoic collisions which formed the Brasiliano orogeny. The Brasiliano orogeny can be found on the east and northeastern coast of Brazil. Also in this region can be found some remnant aulacogens and rifts from the South America-Africa breakup period.Dillenburg Hesp 2008 19 In the Brasiliano orogeny can be found a group of provinces and belts which make up the Brasiliano orogeny. The one the João Câmara earthquake is involved with is the Borborema Province, a structurally complex wide exposure of Precambrian rocks that cover an area of roughly 400000 km2 sqmi in northeastern Brazil.Araujo Neto Santos Souza Barreto 2018 90 The Borborema Province consists of five sub-provinces which are separated by shear zones which vary in scale. Deformation in these shear zones are still continuing, therefore seismicity can take place.Araujo Neto Santos Souza Barreto 2018 91 Earthquake left|thumb|250px|Map of the sequence. The yellow star represents the 5.1 quake, the red dashed line represents the extent of the sequence and the thin black lines represent fault lines. The w n 5.1 earthquake which occurred near João Câmara, a town with a population of 22,000, was the part of an earthquake swarm which started on 5 August 1986, when a magnitude 3.3 earthquake was strongly felt in the town of João Câmara.Ferreira Takeya Costa Moreira 1987 1042 This, in the next days was followed by multiple 3.0+ quakes until 11 September, with the largest quake being a R 4.2. Later, the sequence was reactivated when the largest earthquake of the sequence, the João Câmara mainshock, struck with a magnitude of R 5.1. This triggered a heavy frequency of aftershocks of 3.0+ quakes throughout December and January until the end of January, with the largest aftershock being a R 4.4. The amount of aftershocks over the magnitude of 3 continued to decrease in frequency until it ended in the later months of 1988. On 10 March 1989, the sequence got reignited when a m y 5.0 struck near the first mainshock, causing additional minor damage at João Câmara.M 5.0 – 20 km ENE of São Paulo do Potengi, Brazil https://earthquake.usgs.gov/earthquakes/eventpage/usp0003st3/executive United States Geological SurveyObtendo Catálogos https://www.moho.iag.usp.br/rq/event March 5, 2023 Centro De Sismologia – USP pt Thousands of events with a magnitude of 0+ were recorded,Ferreira Takeya Costa Moreira 1987 1042 including 15 earthquakes with a magnitude of 4.0+.Takeya Ferreira Pearce Assumpçao 1989 117 The fault plane solutions for the mainshock and the other events have a mutual agreement which indicates southwest–northeast directed strike-slip faulting with a slight normal component in a linear manner along the Samambaia Fault.do Nascimento Pearce Takeya 2002 ESE 8-8 Before the 1986 earthquake in the region's history, the last seismic activity had occurred in 1952 and 1983 which was also a small sequence of earthquakes. Six years earlier, a b n 5.2 earthquake had also struck nearby, in Ceará;M 5.1 – 32 km SE of Chorozinho, Brazil https://earthquake.usgs.gov/earthquakes/eventpage/usp0001aw9/executive United States Geological Survey hence why the northeast of Brazil is considered to be the most seismically active region of the country.Ferreira Takeya Costa Moreira 1987 1042 Impact and response Property damage from the 5.1 was widespread mostly near João Câmara; although in the same place minor damage was caused in the August–September 1986 events as well. More than 4,000 homes were destroyed or damaged; 500 of those were rebuilt using a typical design made by the Brazilian Army, which consists of timber panels with concrete infill. Multiple buildings other than homes made of brick or stone suffered extensive amounts of cracks. In some cases including the church of the city suffered collapsing of walls. A seriously damaged hospital and a few schools were completely rebuilt of reinforced concrete. Out of the brick buildings, buildings made of poor quality brick were mostly damaged. Cracks or wall collapses usually happened on buildings with poor mortars or sun-dried bricks with poor quality. Collapses of tiled roofs were also widespread.Takeya Ferreira Pearce Assumpçao 1989 118 Newer buildings and buildings made of concrete received little to no damage.Takeya Ferreira Pearce Assumpçao 1989 119 More than 10,000 people were displaced as a result of the earthquakes, mostly in fear of landslides. As a response to the earthquake, four vertical component short period seismometers were deployed in the area in order to locate events in a more easier way and understand the characteristics of the earthquakes.Ferreira Takeya Costa Moreira 1987 1042 José Sarney, the president of Brazil, as well as several other ministers, visited the area which was hit by the earthquake. Camps were also set-up to shelter displaced residents.Maior tremor de terra registrado no RN completa 35 anos https://g1.globo.com/rn/rio-grande-do-norte/noticia/2021/11/30/maior-tremor-de-terra-registrado-no-rn-completa-35-anos.ghtml March 5, 2023 globo.com pt See also List of earthquakes in Brazil References Sources Dillenburg S. R. https://link.springer.com/book/10.1007/978-3-540-44771-9 Geology and Geomorphology of Holocene Coastal Barriers of Brazil Hesp P. A. 2008 Springer 978-3-540-44771-9 19 10.1007/978-3-540-44771-9 Araujo Neto J. F. Santos G. L. Souza I. M. B. A. Barreto S. B. Santos L. C. M. L. Bezerra J. P. S. Carrino T. A. 2018 pt Integração de sensoriamento remoto, aerogeofísica e análise estrutural no mapeamento geológico: estudo de caso da região de Vieirópolis, Província Borborema, Nordeste do Brasil https://www.revistas.usp.br/guspsc/article/view/140834 Geologia USP Serie Cientifica 18 3 89–103 10.11606/issn.2316-9095.v18-140834 135205903 free Takeya M. K. Ferreira J. M. Pearce R. G. Assumpçao M. Costa J. M. Sophia C. M. 1989 The 1986–1988 intraplate earthquake sequence near João Câmara, northeast Brazil—evolution of seismicity https://www.sciencedirect.com/science/article/abs/pii/0040195189900620 Tectonophysics 167 2–4 117–131 10.1016/0040-1951(89)90062-0 1989Tectp.167..117T subscription do Nascimento A. F. Pearce R. G. Takeya M. K 2002 Local shear wave observations in João Câmara, northeast Brazil Journal of Geophysical Research 107 B10 ESE 8-1-ESE 8–9 10.1029/2001JB000560 2002JGRB..107.2232D free Ferreira J. M. Takeya M. Costa J. M. Moreira J. A. Assumpçao M. Veloso J. A. V. Pearce R. G. 1987 A continuing intraplate earthquake sequence near João Câmara, northeastern Brazil-Preliminary results https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/GL014i010p01042 Geophysical Research Letters 14 10 1042–1045 10.1029/gl014i010p01042 1987GeoRL..14.1042F subscription Further reading Costa C. Alvarado A. Audemard F. Audin L. Benavente C. Bezerra F. H. Cembrano J. González G. López M. Minaya E. Santibañez I. Garcia J. Arcila M. Pagani M. Pérez I. Delgado F. Paolini M. Garro H. Hazardous faults of South America; compilation and overview Journal of South American Earth Sciences 104 2020 0895-9811 10.1016/j.jsames.2020.102837 102837 2020JSAES.10402837C 225204452 none External links 482615 Category:1986 earthquakes Category:1986 in Brazil Category:November 1986 in South America João Câmara earthquake