Intraplate seismicity in Pedra Preta (RN) in the period from 2013 to 2014

Authors

  • Cristiane de Souza Costa Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte - UFRN
  • Joaquim Mendes Ferreira Departamento de Geofísica, Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte - UFRN,
  • Heleno Carlos de Lima Neto Universidade Potiguar - UnP
  • Francisco Hilário Rego Bezerra Departamento de Geologia, Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte - UFRN
  • Maria Osvalneide Lucena Sousa Departamento de Geologia, Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte - UFRN

DOI:

https://doi.org/10.11606/issn.2316-9095.v17-121972

Keywords:

Seismic activity, Determination of hypocenters, Focal mechanism, Seismogenic faults, Seismotectonics.

Abstract

The seismic activity in Pedra Preta (RN), Northeast of Brazil, region of main intraplate seismicity of the country, began in December 2010. Before that year, there was no record of earthquakes in this area. During 2013 and early 2014, the seismographic network deployed in Pedra Preta registered 273 local earthquakes in 3 or more stations. Of these, 50 events with the best readings of the arrival times of the P and S waves were selected to determine velocity model (Vp/Vs = 1.72 and Vp = 5.90 km/s) and their hypocenters were calculated, with HYPO71 software. For the determination of the composed focal mechanism, it was realized a new selection with earthquakes obeying more stringent criteria for the hypocenters (epicenters located within the network with mean arrival-time residue ≤ 0.01 s, number of observations ≥ 10, mean horizontal error < 0.1 km, mean vertical error < 0.1 km), having been selected 24 events by these criteria. The hypocenters of earthquakes show that the seismogenic fault is about 3 km long, with earthquakes between 2.3 and 5.8 km deep. The parameters of seismogenic fault were obtained by combining the method of least squares and FPFIT software (strike = 254º, dip = 67º and the rake = -66º), indicating a normal fault. The hypocenters and focal mechanism were used to verify if there was possible correlation with geological features mapped in the area and the conclusion is that there are no mapped geological features that may be directly related to the seismic activity studied.

Downloads

Download data is not yet available.

Downloads

Published

2017-08-01

Issue

Vol. 17 No. 2 (2017)

Section

Articles

License

Authors who publish in this journal shall comply with the following terms: 

  1. Authors keep their copyright and grant to Geologia USP: Série Científica the right of first publication, with the paper under the Creative Commons BY-NC-SA license (summary of the license: https://creativecommons.org/licenses/by-nc-sa/4.0 | full text of the license: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode) that allows the non-commercial sharing of the paper and granting the proper copyrights of the first publication in this journal.
  2. Authors are authorized to take additional contracts separately, for non-exclusive distribution of the version of the paper published in this journal (publish in institutional repository or as a book chapter), granting the proper copyrights of first publication in this journal.
  3. Authors are allowed and encouraged to publish and distribute their paper online (in institutional repositories or their personal page) at any point before or during the editorial process, since this can generate productive changes as well as increase the impact and citation of the published paper (See The effect of Open Access and downloads on citation impact).

How to Cite

Costa, C. de S., Ferreira, J. M., Lima Neto, H. C. de, Bezerra, F. H. R., & Sousa, M. O. L. (2017). Intraplate seismicity in Pedra Preta (RN) in the period from 2013 to 2014. Geologia USP. Série Científica, 17(2), 123-129. https://doi.org/10.11606/issn.2316-9095.v17-121972