The 2006 West Java earthquake was one of the devastated tsunami events in Indonesia. In this study,
we re-estimated the slip distribution of the 2006 earthquake by tsunami waveform inversions of tide
gauge data using phase-corrected Green’s functions. Then, to evaluate our slip models, we performed
tsunami inundation simulations and computed the K and 𝜅 numbers.
The slip distribution obtained with an assumed rupture velocity of 1.25 km/s shows that the
maximum slip was around 5.9 to 11.8 m in the shallower part near the trench. The total source length
was 300 km, while the seismic moment calculated from this source was 6.4 x 1020 Nm (Mw = 7.8). The
dominant shallow slips in our slip models support the previous study that classified the 2006 earthquake
as a tsunami earthquake event.
We successfully updated the source model based on the previous study, although we found
that the K and 𝜅 numbers of our slip models were unsatisfied with recommended standard values. We
also found that the tsunami inundation simulation results were still underestimated around the
Pangandaran, Cilacap, and Binangun. One possible reason for the underestimation at some survey points
may be local (near coasts) bathymetry effects. Furthermore, we tried to assess the possible locations of
the landslide source in front of the Permisan region. We found that a near-coast landslide source looks
better to reproduce the extreme tsunami heights in the Permisan region. However, a landslide source far
from the coastline was preferable to reproduce the tsunami heights for the western and eastern sides.
Nevertheless, further studies are needed to determine more accurate landslide sources.
Keywords:
2006 West Java earthquake, Tsunami waveform inversion, Tsunami inundation simulation.