This is why the Earthquake often occurs in Lombok recently
Tectonically, Lombok is an active seismic region.
Lombok has the potential to be rocked by an earthquake because it is located between 2 earthquake generators from the south and north.
From the south there is an Indo-Australian plate subduction zone which slides down the island of Lombok, while from the north there is a geological structure of Faulting Up Flores (Flores Back Arc Thrusting).
“This rising fault is the pathway extending from the sea of Bali to the east to the Flores Sea. So it is not surprising that Lombok is indeed prone to earthquakes because the fault line on Flores is very close to the island of Lombok,” said Daryono, Head of the BMKG Tsunami Information and Early Warning Information through his official broadcast. .
He continued, if we look at the map of seismic activity or seismicity of Lombok Island, it seems that all of Lombok Island has many epicenter points.
This means that there are many earthquake activities in the region.
“This earthquake was in the same zone (with the 29 July earthquake) and caused damage. Currently the team is there to conduct inspections and mapping. The center was on land yesterday,” said Head of the Center for Volcanology and Geological Disaster Mitigation ( PVMBG) Kasbani Geological Agency in PVMBG building, Bandung City, West Java, Monday (08/06/2018).
Kasbani explained that the earthquake that shook Lombok was caused by faults or fault fault types that rose in the back arc zone of Flores (Flores Back Arc). The earthquake centered at coordinates 116.48 degrees East Longitude and 8.37 degrees South Latitude with a magnitude of 7.0 and at a depth of 15 km it caused a small tsunami with a maximum height of 0.13 meters in the village of Carik and 0.1 meters in the village of Badas , Lombok, NTB.
Although the hypocenter depth and magnitude are varied, it is clear that the Lombok region is an earthquake-active region that originates from plate subduction, Fault Increases Flores and local faults on Lombok Island and its surroundings.
From the distribution of this seismicity, it is quite a basis to say that Lombok is indeed prone to earthquakes.
Historical records show that the island of Lombok has often experienced destructive earthquakes, namely:
1. Labuantereng earthquake and tsunami, Lombok, July 25, 1856
2. Lombok Earthquake on 10 April 1978 M = 6.7 (many houses were damaged)
3. Lombok Earthquake May 21, 1979 M = 5.7 (many houses were damaged)
4. Lombok earthquake October 20, 1979 M = 6.0 (many houses were damaged)
5. Lombok earthquake May 30, 1979 M = 6.1 (many houses were damaged and 37 people died)
6. Lombok Earthquake January 1, 2000 M = 6.1 (2,000 houses damaged)
7. Lombok earthquake 22 June 2013 M = 5.4 (many houses were damaged)
The description of the earthquake’s historical record would be enough to assess that Lombok is indeed prone to earthquakes.
Regarding the aftershocks, Daryono ensured that the aftershocks that occurred in his strength would not be as big as the main earthquake.
“The frequency of the lombok aftershocks is getting rarer and the strength is getting smaller. From the aftershocks trend, it indicates that there is very little chance of an earthquake with greater strength than the main earthquake,” Daryono said.
This kind of natural condition is something that must be accepted, so that inevitably, like it or not, all of that is a consequence that must be faced as a resident who lives and rides on the boundary of the tectonic plate meeting.
“The solution, we must continue to increase capacity in understanding earthquake science, how to survive earthquakes and how to mitigate earthquakes, so that we can survive and live in harmony with nature,” he said. (Gloria Setyvani Putri)