Abstract
September 28th, 2018, Donggala-Palu earthquake M 7.5 occurred at depth of 12 km and generated tsunami to be released off the coast in Palu Bay. The tsunami that occurred in Palu was very interesting because the results of the earthquake source mechanism Palu had a type of strike-slip fault that should not have generated a tsunami. This study purpose to estimate the characteristics of the Donggala-Palu tsunami based on rupture duration ( and orientation fault activated using the HC-plot method. The data used in this study are data waveforms from 17 seismic stations and CMT Global catalog data with the area of research 0.87 0 N-1.78 0S dan 118.640E- 120.95 0E. The waveform data used is a phase P-PP vertical component signal with a Bandpass-filter 1-5 Hz for determination . The fastest rupture duration from the earthquake source is obtained from the calculation of each station. Delay time measurement after P wave for 90% (T0.9), 80% (T0.8), 50% (T0.5), dan 20% (T0.2) from its peak value. Then the HC-plot method is used to estimate the orientation of generator fault Palu earthquake and the direction of rupture from the focal mechanism. From the results of processing obtained 2 pairs of seismic stations with almost the same distance but with different azimuths. The fastest rupture duration is at BBSI station with value of 82.014 s and distance from station to epicenter . So that the rupture direction is in the azimuth from the north. The result of fault orientation was obtained hypocenter distance to the centroid for nodal plane 1 is 6.32 km and nodal plane 2 is 30.17 km with distance centroid to hypocenter is 31.22 km. So in Palu earthquake, the tsunami generator fault was in nodal plane 1 with direction north-south. Criteria obtained indicate that the Palu earthquake M 7.5 has potential for a tsunami because of its value has meet ≥ 65 s, but from the result of the focal mechanism direction field not passing through the Palu bay is thought to be another parameter that generates a tsunami and Palu koro fault line uncharted.
Highlights
M 7.5 occurred at depth of 12 km and generated tsunami to be released o↵ the coast in Palu Bay
The fastest rupture duration is at BBSI station with tsunami Donggala-Palu berdasarkan rupture duration (Tdur) value of 82.014 s and distance from station to epicenter 5.5590
That the rupture direction is in the azimuth 1500 from the north
Summary
Daerah Palu merupakan salah satu kawasan seismik aktif di Indonesia. Tingginya tingkat aktivitas kegempaan di kawasan ini tidak lepas dari lokasinya yang berada pada zona benturan tiga lempeng tektonik utama dunia, yaitu Indo-Australia, Eurasia dan Pasifik (Ibrahim dkk., 2010). Tsunami yang terjadi di Palu sangat menarik karena dari hasil mekanisme sumber gempa Palu memiliki jenis petahan strike-slip yang seharusnya tidak membangkitkan tsunami. Kriteria untuk gempa tektonik dapat menyebabkan tsunami adalah gempa bumi tersebut memiliki episenter di tengah laut dengan kedalaman dangkal (030 km), magnitude dengan kekuatan sekurang-kurangnya Magnitudo 6.5, serta mekanisme sumber dengan pola sesar naik atau turun. Penelitian ini bertujuan untuk mengestimasi karakteristik tsunami Donggala-Palu berdasarkan rupture duration (Tdur) dan orientasi sesar teraktifkan menggunakan metode HC-plot. Pada penelitian yang dilakukan oleh (Madlazim dan Hariyono, 2014) gempabumi berpotensi terjadi tsunami memiliki kriteria Tdur 65s, Td 10s, T50EX 1s, TdurxTd 650s2, dan T50EX xTd 10s2. Selain Tdur mekanisme sumber dapat digunakan sebagai parameter tambahan lainnya untuk memberikan informasi orientasi geometri sesar yang terjadi di sumber. Dengan menentukan bidang patah teraktifkan pada event gempabumi maka dapat memetakan sesar yang menjadi generator pembangkit utama saat terjadi gempabumi
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
