Jakarta: Indonesia was rattled by more than 11,500 earthquakes last year, almost double the annual average of the past decade, according to the nation’s meteorological agency.

The archipelago was hit by 11,557 temblors in 2018, with 297 of them packing a magnitude of more than 5 on the Richter scale, according to data from the Meteorology, Climatology and Geophysics Agency. That was more than the average 6,000 quakes recorded in recent years, Antara news agency reported, citing the meteorological agency’s head, Dwikorita Karnawati.

Indonesia’s 17,000 islands are prone to earthquakes because the country straddles the Pacific Ring of Fire — an arc of fault lines and volcanoes that causes frequent seismic upheavals. In September more than 4,000 people were killed in Central Sulawesi after an earthquake and tsunami struck the island. That was preceded by a series of deadly earthquakes earlier last year that rattled the popular tourist destination of Lombok island, near Bali.

The Southeast Asian nation also recorded for the first time liquefaction, a phenomenon that causes soil to lose its strength after violent shaking. It was seen in Sulawesi last year, and after a tsunami triggered by a volcanic eruption in the Sunda Strait between Java and Sumatra in December, Karnawati said.