Banca de QUALIFICAÇÃO: EDUARDO ALEXANDRE SANTOS DE MENEZES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : EDUARDO ALEXANDRE SANTOS DE MENEZES
DATA : 05/12/2016
HORA: 10:00
LOCAL: Auditório do DGEF
TÍTULO:

Seismicity in Irauçuba-CE from September 2015 until March 2016 

PALAVRAS-CHAVES:

seismology, seismicity, intraplate, hypocentral location, NE Brazil, seismotectonics

PÁGINAS: 20
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

The seismic activity of the Northeast of Brazil is well observed by several eventsthat occurs at the region for many years, which happens in some areas that are known asactive areas. Many of these events are perceived by population of the areas where theyoccur, because even if these events do not reach great magnitudes, they frighten nativesand in some cases even cause small damages in houses such as small cracks in the wallsand displacement of tiles. An example of this case is the city of Irauçuba, located in theNorthwest portion of the state of Ceará, 175 km from its capital, Fortaleza. The seismicactivity in Irauçuba is known for a while, as we can testify in 1991’s case, in which severaltremors occurred to the south in the city of Juá, district of Irauçuba, being that the tremorof greater magnitude reached 4.9 of magnitude, surpassed only in Ceará by the tremorof Pacajus of 1980 (5.2 Mb). The former quoted event (Irauçuba) was the one of greatestmagnitude registered in the Northwest of Ceara, which is located in northeastern Brazil,where the records show the highest intraplate seismicity in Brazil. A new intense seismicactivity began in September 2015 at Irauçuba proximities, this time a stronger intensity(IV and V, Mercalli) was observed at the districts of Cuité and Passarinho. Several eventswere also felt by the population of a large area of Irauçuba. These were registered by theMorrinhos seismological station (NBMO), which belgons to the RSISNE seismographicnetwork, that is about 54 km from the epicentral area. During the period from 09/2015until the beginning of 03/2016, a seismographic network was installed in the Region ofIrauçuba to study the seismic activity in the city. In this period, the seismographic networkregistered a total of 649 local earthquakes, in which 196 events recorded in at least 4stations were selected for analysis. The network was composed of 7 seismographicstations, in which 6 digital stations with accelerometer and one digital station with shortperiod seismometer of three components. The preliminary results confirmed that this isa new epicentral area, located northwest from where the tremor occurred of magnitude4.9 in 1991. Although the results are still preliminary, the hypocentral parameters havealready been determined, as well as a first approximation of a (subvertical) NE-SW faultwhich the events are related. The events that will be used to determine a composite focalmechanism have also been selected

MEMBROS DA BANCA:
Presidente - 1451214 - ADERSON FARIAS DO NASCIMENTO
Externo à Instituição - FLAVIO LEMOS DE SANTANA - UFRN
Interno - 350640 - FRANCISCO HILARIO REGO BEZERRA