TSUNAMI HAZARD ASSESSMENT IN MOZAMBIQUE COAST
Supervisor: Yushiro FUJII
The purpose of this study is to assess tsunami hazard in Mozambique coast, specifically to estimate tsunami heights as well as tsunami arrival times considering near-field and far-field tsunami source models. The softwares used for the study were TUNAMI-N2 code and Tsunami Travel Time (TTT) for near-field tsunami, TUNAMI-F1 for far-field. Tsunami propagation was calculated by using GEBCO one arc-minute bathymetry grid data. We used 2 tide gauges and 20 assumed stations positioned along the Mozambique coast as outpoints. For near-field tsunami simulations, we considered normal-fault type events in the Mozambique channel. The seven source locations were assumed with two magnitudes (Mw 7.0 and Mw 8.0) and three depths (0, 5 and 10 km), totalizing 42 cases. For far-field tsunami simulations, six tsunami sources with the size of Mw 8.0 to Mw 9.3 were adopted. We found that for all the source models with Mw 7.0 the calculated tsunami heights do not exceed 0.4 m and due to that, the coast would not be at high risk if events of this size happened. Regarding the source models with Mw 8.0, the maximum tsunami heights were of 3 m or 2.5 m for some regions. The minimum travel times of tsunami to reach the coastal area are less than 10 min for some regions near the source. If events of this size happened, the coastal area of Mozambique would be in risk of damages. For far-field, the coast of Mozambique could be at risk if the event located in south Sumatra with Mw 9.1 (slip amount of 13 m, fault length and width of 550 km and 175 km, respectively) or with Mw 9.3 (slip amount of 15 m, fault length and width of 900 km and 175 km, respectively) took place, because the tsunami which its height of 2 m to 3 m could cause some damages to the coastal region. The time of 9 hours, that the tsunamis took to reach the first region in the coast of Mozambique, can allow people to evacuate.
|Citation: ||Bulletin of IISEE, 44, 19-24.|