Banca de DEFESA: EDUARDO ALEXANDRE SANTOS DE MENEZES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : EDUARDO ALEXANDRE SANTOS DE MENEZES
DATA : 02/11/2017
HORA: 09:00
LOCAL: Laboratório sismológico
TÍTULO:

STUDY OF THE SEISMIC ACTIVITY IN IRAUÇUBA, NE BRAZIL FROM SEPTEMBER 2015
UNTIL MARCH 2016

 

PALAVRAS-CHAVES:

Seismic activity; Focal mechanism; hypocentral determination; seismogenic faults; Seismotectonics, intraplate seismicity

PÁGINAS: 74
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

In the present paper we analyze a set of 294 digitally recorded events during a campaign in the Irauçuba region, Ceará State, from September 2016 until Februabry 2016. In this region, a 4.8 mb intraplate event has already been recorded in 1991. Since then, no earthquake with magnitude above 1.0 mb has been recorded. From the recorded events in this recent campaign, 69 of them were used to determine the half-space model parameters Vp/Vs =1,69 and Vp = 6,20 km/s. From this model parameters the hypocentres were calculated using the HYPO71 programme. For the focal mechanism determination, we selected 22 better located events using a more restrictive selection and these events illuminate a seismogenic fault – Passarinho Fault – with approximately 2 km in length, with depth between 8 and 9 km. The kinetic parameters of this fault were obtained by fitting a fault plane and using the FPFIT programme with strike = 45°, dip = 52° e o rake = -151°, thus characterizing a normal fault. The epicentres and focal mechanism were used to verify whether or not they were associated with local mapped geological features. Despite not having a clear correlation between the Passarinho Fault and the Precambrian foliation, there is a correlation with the kind of fault and the compressive maximum direction between the Passarinho Fault and the seismicity recorded in 1991. In both cases the focal mechanisms indicate normal faulting and the maximum horizontal stress has approximately E-W direction.

MEMBROS DA BANCA:
Presidente - 1451214 - ADERSON FARIAS DO NASCIMENTO
Interno - 1315614 - DAVID LOPES DE CASTRO
Externo à Instituição - GEORGE SAND LEAO ARAUJO DE FRANCA - UnB