Hundreds of earthquakes in a week: Indonesia really does shake often

From October 7, 2026 to October 13, 2026, BMKG recorded 317 earthquakes in and around Indonesia. That is one every 32 minutes on average. Only 28 of them were reported as felt. The strongest was magnitude 5.8, 230 km northwest of Tahuna, Kep. Sangihe, Sulut, on October 8, 2026.

Why does Indonesia have so many earthquakes?

According to BMKG, Indonesia sits where three large plates of the Earth meet: the Indo-Australian, Eurasian and Pacific plates. They keep moving and pressing against each other. When that pressure is released, an earthquake happens. So earthquakes in Indonesia are not rare; they happen every day, and most are not felt.

General explanation from BMKG, not a figure from our data.

What is magnitude?

Magnitude measures the energy an earthquake releases at its source. Each whole step up means about 32 times more energy. So a magnitude 6 releases about 32 times the energy of a magnitude 5, and about 1,000 times that of a magnitude 4.

General explanation from the USGS.

This week's earthquakes by magnitude:

What people feel also depends on depth and distance. 270 of this week's 317 earthquakes were shallow, less than 60 km below the surface. Shallow earthquakes are felt most strongly above their source.

Facts from the long record

• The largest earthquake recorded in Indonesia was magnitude 9.1, on December 26, 2004. Its epicentre was in the Indian Ocean off the west coast of Aceh. Its tsunami struck the coast of Aceh province, including the city of Banda Aceh.
• Since 1900, 439 earthquakes of magnitude 6.5 or more have been recorded in and around Indonesia, 3.5 a year on average.
• The strongest so far in 2026 was magnitude 7.7, 30 km northeast of Mbay, Nagekeo, NTT, on August 15, 2026.

Older records come from the USGS catalogue, recent ones from BMKG. Records from the early 20th century are less complete than today's, so the true number may be higher.

What happened on 26 December 2004?

The earthquake set off a tsunami. According to BNPB, waves of about 30 metres arrived roughly 10 minutes after the shaking. More than 167,000 people died in Indonesia (USGS), and more than 230,000 died or went missing across the Indian Ocean countries (BNPB).

Those ten minutes are why. If you are on the coast during an earthquake, move to higher ground at once without waiting for a siren, especially if the sea suddenly recedes. According to BMKG, a sudden drop in sea level is one of the early signs of a tsunami.

Prepare before an earthquake

Earthquakes cannot be predicted yet. What we can prepare is how we respond. BNPB recommends an emergency bag that lasts three days:

• Important documents in one waterproof container: birth certificates, land or house certificates, diplomas and insurance papers.
• Some cash.
• Drinking water, long-lasting food and a change of clothes.
• Personal medicines and a first-aid kit.
• A flashlight, a whistle, and a radio or phone with a spare battery.

From BNPB's disaster preparedness pocket book.

What to do during and after an earthquake

According to BMKG, during an earthquake:

• Inside a building: Protect your head and body from falling building debris.
• Outside or in an open area: Avoid nearby buildings.
• At the beach: Move away from the coast to avoid a tsunami.
• In the mountains: Avoid areas where landslides may occur.

After an earthquake:

• Leave the building in an orderly way.
• Use ordinary stairs, not escalators or lifts.
• Do not re-enter a building after an earthquake; it may collapse.
• Aftershocks may still occur near the earthquake area.

This article summarises BMKG records and the USGS catalogue. It is not an early warning or an earthquake forecast. For official information, follow BMKG.