Voice of America (VOA) provides an explainer on why the 5.6 magnitude earthquake left more than 260 dead and hundreds injured as buildings crumbled

BODIES continued to be pulled from the debris on Tuesday morning in the hardest-hit city of Cianjur, located in the country’s most densely populated province of West Java and some 217 kilometers (135 miles) south of the capital, Jakarta. A number of people are still missing.

While the magnitude would typically be expected to cause light damage to buildings and other structures, experts say proximity to fault lines, the shallowness of the quake and inadequate infrastructure that cannot withstand earthquakes all contributed to the damage.

Here’s a closer look at the earthquake and some reasons why it caused so much devastation:

Was Monday’s earthquake considered ‘strong’?
The U.S. Geological Survey said the quake late Monday afternoon measured 5.6 magnitude and struck at a depth of 10 kilometers (6.2 miles).

Quakes of this size usually don’t cause widespread damage to well-built infrastructure. But the agency points out, ‘There is not one magnitude above which damage will occur. It depends on other variables, such as the distance from the earthquake, what type of soil you are on, building construction’ and other factors.

Dozens of buildings were damaged in Indonesia, including Islamic boarding schools, a hospital and other public facilities. Also damaged were roads and bridges, and parts of the region experienced power blackouts.

So why did the quake cause so much damage?
Experts said proximity to fault lines, the depth of the temblor and buildings not being constructed using earthquake-proof methods were factors in the devastation.

According to the Voice of America report: ‘Even though the earthquake was medium-sized, it (was) close to the surface … and located inland, close to where people live,’ said Gayatri Marliyani, an assistant geology professor at Universitas Gadjah Mada, in Yogyakarta, Indonesia. ‘The energy was still large enough to cause significant shaking that led to damage.’

The worst-affected area is close to several known faults, said Marliyani.

A fault is a place with a long break in the rock that forms the surface of the earth. When an earthquake occurs on one of these faults, the rock on one side of the fault slips with respect to the other.

‘The area probably has the most inland faults compared to the other parts of Java,’ said Marliyani.

She added that while some well-known faults are in the area, there are many other active faults that are not well studied.

For the full report visit here.