BANDUNG. According to the record of Mt. Batur Observation Post, Bali, after the earthquake 6, 8 SR shaking Nusa Dua, Bali on November 13th, 2011 at 11:16:27 WITA then it was followed by 11 aftershock earthquake. One is earthquake felt in intensity of II MMI and also small earthquakes recorded by seismograph.
The main earthquake happened in Thursday, October 13th, 2011. Based on the information of BMKG and USGS, US, the earthquake parameter follows: the main earthquake happened at 11:16:27 WITA, 10 km in depth, 143 km southwest of Nusa Dua. The aftershock earthquake happened then between 12 up to 23 o’clock for 11 times, that was released by the Center for Vulcanology and Disaster Mitigation, Geological Hazard Mitigation (PVMBG), Geological Agency accepted by editorial staff of esdm.go.id, Tuesday (15/11/2011).
Based on the position of epicenter in 10 km depth (BMKG) and 35, 2 (USGS) is predicted that the earthquake associated with active fault developing in the seabed of South Hindia Ocean of Bali and Java Island.
The condition of earthquake-affected areas, based on the view of topography map of Bali Island, generally could be classified becoming 3 morphology: land, volcano, and moderate to steep hills. Land morphology consists of alluvial and coastal plains, in south part (Kuta, Jimbaran, Nusa Dua, and others) and north part (Seririt, Calukan Bawang. Gilimanuk, and others). Volcanic morphology is surrounding Mt. Batur and Mt. Agung, consisting of volcano peak, volcano body, and volcano foot. The morphology is composed by volcanic sedimentation as the result of Mt. Batur and Mt. Agung activity. The morphology of moderate-steep hills are in west and central part of Ball Island. The morphology consists of volcanic talus rocks.
While the geological structure in form of fault developing in Bali Island, most tend toward North-South and Northwest-Southeast, especially in west, central and north of Bali Island.
Based on the observation and analysis of Emergency Response Group (TTD), PVMBG in the location of earthquake Nusa Dua, Bali produced a quite strong shaking especially in Denpasar, so it often causes panic. The earthquake causes building damage and some injured. The most drastic disaster happened in Denpasar; some buildings are minor to moderate damaged such as fall roofs, wall cracking, and released plaster wall.
The most severely damaged area is the shopping center in which there were many wall cracks, and one of its walls almost broken. The damage also happened in one of health center, in which the roof fell down and damaged the roof. The damage in Tabanan focused in Padangan Village, in which a house collapsed and its walls moved. One school had many wall cracking and part of the plaster wall released.
While the damage in other areas are minor such as fall roof and wall cracks, which spread in some areas in Bali Island. The earthquake shaking also caused community panic in Denpasar and surrounding and caused 90 injured people, in detail: 88 are outpatients and 2 inpatients.
TTD also investigated Banyuwangi District, East Java. This is done because the location of Banyuwangi, which is close to the epicenter and based on accepted information, Banyuwangi also suffered damage from earthquake shaking of Nusa Dua.
The investigation of TTD in Banyuwangi is below:
1. Muncar Sub-District
Kemendung Village: 31 houses damaged in form of 5 severely damage, 22 minor damage, 3 collapses, and 1 moderate damage. Tembokrejo Village: 1 kitchen of a house was severely damage. SumberSewu Village, Krajan: 3 house were severely damage in one of its room, and 1 minor damage in form of wall cracks. Tambakrejo Village: 1 house was severely damage, 1 house was collapse. Tapanrejo Village, Kedungdandang: 1 house was severely damage, Krajan Village; 1 house was minor damage.
2. Bangorejo Sub-District
Some community’s houses damaged, while governmental infrastructure such as sub-district office, schools, health center, and others were not damage/lost. The damaged houses: 1 severely damage, 3 moderate damages (cracks surrounding the house, fall walls or damage roof), and 2 minor damages in form of wall cracks and fall roof.
3. Tegalsari Sub-District, Tegairejo Village
Tugurejo: 1 house was collapse and 1 person was injured because of the ruin of the house. (AK)
