TSUNAMI NUMERICAL SIMULATION USING HYPOTHETICALLY EARTHQUAKE IN SOUTH JAVA SEA (CASE STUDY: NEW YOGYAKARTA INTERNATIONAL AIRPORT, KULON PROGO, YOGYAKARTA)

• Main Author: Oky Setiawan, Rinaldi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30503
• Institution: Institut Teknologi Bandung

A zone with small seismic activity during long periods, which can accumulate a high amount of energy, is called a seismic gap. In Indonesia, one of these zones is located offshore south Java, which extends from Yogyakarta to Pacitan, East Java. There are only two records of tsunamis generated by earthquakes in this zone: Banyuwangi Tsunami in 1994 with Mw = 7,8 and Pangandaran Tsunami in 2006 with Mw = 7,7. Kulon Progo is one of the regencies along the coast of Yogyakarta that faces the Indian Ocean directly. The simulation in this study is focused on simulating the generation and propagation of tsunamis caused by earthquakes using the Cornell Multi – grid Coupled Tsunami (COMCOT) v.1.7 model, with GEBCO (General Bathymetric Chart of the Oceans) 30” and DSM (Digital Surface Model) TerraSAR – X 9 m for bathymetry and topography data. The area for this study is the coast of the New Yogyakarta International Airport (NYIA), using a model with single fault hypothetic earthquakes with 3 scenarios: Mw = 7,7, 8,1, and 8,5. The tsunami arrived at the coast of Kulon Progo within a range of 35,32 – 42,57 minutes after the earthquake, with the variation of maximum tsunami heights in each of the scenarios being 1,9 – 2,46 m for Mw = 7,7, 3,4 – 3,64 m for Mw = 8,1, and 8,02 – 9,4 m for Mw = 8,5. The inundation limit in the Banaran village is the largest, about 2,35 – 4,93 km. The farthest distance of the tsunami that inundates the airport is 1,26 km from the coastline of Kulon Progo. The inundation area at the NYIA caused by Mw = 8,5 reached 2,064 km2 , with the range of inundation reaching up to 8,15 m.