I. Gunawan1 , A. Rudyanto2
1Tsunami and Disaster Mitigation Research Center (TDMRC)
2Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG)
Abstract:
The earthquakes sequences that struck the north part of Lombok Island are of the thrusting earthquake type as interaction of the back-arc Flores thrust tectonic system. This earthquake sequences is initiated by significant earthquakes with magnitude M 6.4 (29 July 2018), M 6.9 (05 August 2018) and M 7.0 (19 August 2018). Using hybrid simultaneous displacement spectrum inversion for determining the physic of source characteristic, path effect and amplification effect at the recording seismic sites (PLAI, JAGI, SRBI and TWSI) reveals that the median static stress drop is 28.4 MPa and the Q-factor parameterise is about 64 f0.8. Processing of 8 significant earthquakes ranges from M. 4.9 to M 6.4 also indicates amplification factor of the SRBI and TWSI stations to be app. 4 - 6 Hz and 15 – 18 Hz respectively. PLAI is assumed as reference station due to its MASW measurement of app. 1385 m/s (rock site category).
