Tsunami Hazard Analysis for Batangas Bay, Phillipines
We performed a hydrodynamic analysis of tsunami waves affecting a site in Batangas Bay, Phillipines.
eCoast performed a hydrodynamic analysis of tsunami waves affecting a site in Batangas Bay, Phillipines. The model considered subduction zone earthquake located along the Manila Trench which ranged in magnitude from8.4 to 9.0.
For the smaller events, modelled wave amplitudes were on the order of +/- 1 m. The presence of an unfavourably located high slip patch with twice the average co-seismic slip positioned on either a shallow or deep fault segment did not have an appreciable effect on the modelled wave heights.
tsunami induced current speeds were modelled to be in the order of 0.5 m/s or less for the Mw 8.4 cases and up to 2 m/s for the MW 9 source. Given the extreme tsunami and earthquake events of the past decade (i.e. Sumatra 2004 and Japan 2011), the possibility of a very large earthquake on the Manila Trench with a 25+ m slip asperity positioned at the entrance on the Verde Island Passage cannot be entirely ruled out. However, such an event should be less likely to occur than a smaller earthquake at the same location.
We have shown that due to the relatively sheltered location of the study site within Batangas Bay, typically 'large' earthquakes of magnitude 8.4 with high slip patches located at the entrance to the Verde Island Passage would not produce a catastrophic tsunami.
