According to Indonesia’s Meteorology, Climatology and Geophysics Agency, the country had more than 11,500 earthquakes last year.

The agency said 11,557 earthquakes shook the country in 2018, 297 of them with a magnitude of more than five on the Richter scale, Antara News reported. The number far exceeded the average of 6,000 quakes recorded in the past few years.

One of the deadliest earthquakes claimed more than 4,000 lives in Central Sulawesi last September. A tsunami also followed the earthquake. A series of quakes also struck Lombok island before the Sulawesi earthquake.

Agency head Dwikorita Karnawati said the country also experienced liquefaction during some quakes – a phenomenon that sees soil lose its strength with violent shaking – for the first time in recent history. The phenomenon was seen in the state of Sulawesi in December when a volcanic eruption triggered a tsunami in the Sunday Straits that lies between Sumatra and Java.

Indonesia, an archipelago, is particularly vulnerable to earthquakes due to the country’s location on the Pacific Ring of Fire, an arc of fault lines and volcanoes. Seismic activity is frequent in this area and causes natural disasters such as volcanic eruptions, earthquakes and tsunamis.