Lessons from Lombok

KOMPAS/TOTOK WIJAYANTO

Heavy equipment is used by members of the National Search and Rescue Agency (Basarnas), Monday (08/06/2018), to evacuate victims at Jabal Nur Mosque, Lading-Lading village, Tanjung, North Lombok, West Nusa Tenggara. The mosque collapsed during an earthquake the day earlier. A number of worshipers of the mosque were trapped while conducting Isya Prayer.

Commonly, earthquakes are followed by increasingly smaller aftershocks in subsequent hours and days. In Lombok, however, an earthquake was followed by an even bigger one, sending shocks of fear and panic throughout the region.

Just seven days from the 6.4-magnitude earthquake, another earthquake measuring magnitude 7 hit Lombok on Sunday (5/8/2018) evening. This is despite dozens of aftershocks of the first earthquake still trembling the island until Saturday.

This was surely shocking, considering the common knowledge that earthquakes will only be followed by increasingly smaller aftershocks. It could be that the second earthquake was the major one, with the previous ones merely the opening salvo. It could also be a new pattern of earthquakes that requires deep surveys and research, followed by a comprehensive mitigation effort.

What is clear is that Lombok is highly prone to earthquakes as it is surrounded by two major earthquake triggers. To its south, the Indo-Australian Plate can induce a subduction earthquake and, to its north, there is the Flores back arc thrust. The thrust spans from the Bali sea to the Flores sea, making Bali, Lombok, Sumbawa and Flores prone to earthquakes.

Among these islands, Lombok is the most prone to earthquakes as it also contains many local fault lines. In a map, its epicenter spots are scattered throughout the island. The condition is worsened by Lombok’s cohesive soil – especially in its northern and eastern regions – in the form of sand and alluvium (Daryono in “Earthquake-Prone Lombok”, Kompas, 1/8/2018). In soil with these characteristics, earthquakes resonate widely and even low-magnitude earthquakes can cause significant destructions.

We are in sorrow and wish to convey our deepest condolences for victims of the two earthquakes. Reports of fatalities are still cropping up. The National Disaster Mitigation Agency (BNPB) reported that 98 died and 236 suffered from injuries in the second earthquake.

Science cannot yet predict when and where earthquakes will occur. However, we can always strive to minimize their impacts. First, we need to educate the public on what they should do in the face of earthquakes and possible subsequent tsunamis. Earthquake education is a must in schools and simulations of emergency conditions must be routine.

Considering that Lombok is a popular tourist destination, visitors should also be educated on emergency safety procedures during earthquakes, including how to seek safe places and important evacuation points. Hotel receptionists can inform these procedures to all incoming guests.

On the other hand, earthquake-resistant construction standards is necessary. We know that earthquakes do not kill or hurt people. Collapsing buildings do. These standards can be applied when victims who obtain Rp 50 million (US$3,455.24) in emergency recovery aid from the government start to rebuild their homes.

Disaster mitigation is necessary nationwide, considering that Indonesia is a meeting places of tectonic plates and has many volcanoes and fault lines: the causes of volcanic and tectonic disasters. It is truly important that we take lessons from Lombok.