Dynamical stress analysis of tectonic earthquakes in Nusa Tenggara and its possible relations to the activity of Mt. Rinjani, Indonesia
Penulis/Author
BAKTI SUKRISNA (1); Prof. Dr. Kirbani Sri Brotopuspito (2); Dr. Wahyudi, M.S. (3); Dr.rer.nat. Wiwit Suryanto, S.Si., M.Si. (4); Ade Anggraini S.Si, M.T (5)
Tanggal/Date
5 2017
Kata Kunci/Keyword
Abstrak/Abstract
Some strong earthquakes are associated with increasing of volcanic activity in near and also in far field. This research is to investigate the effect of the tectonic earthquakes in Nusa Tenggara Island area towards the October 25th,2015 eruption of Mt. Rinjani, Indonesia. Three earthquakes occurred before the eruptions; Mw 5 Sumba earthquake on June 10th 2015, Mw 5.8 South of Java earthaquake July 26th, 2016 and Mw 5 South of Bali on August 6th, 2015. In theory, dynamical stress transfer can be calculated by analyzing synthetic seismogram as a waveform simulation at the volcano and the change of dynamical stress can be calculated with the finite-difference numerical method. Our result indicates that the dynamic stress value is still below the threshold value that can trigger eruptions. Simulation of three earthquakes by varying the magnitude of each earthquake shows that dynamic stress changes will surpass the threshold at Mw 7.5. As all the earthquake that used in this study have magnitude smaller then the threshold, it can be concluded that the eruption of Mount Rinjani was triggered by internal factors, and very unlikely triggered by tyhe earthquake we investigated in this study.
