62 Aftershocks Recorded Within Two Hours of Southwest Sumba, Indonesia Quake

JAKARTA, Oct 4 – At least 62 aftershocks were recorded within just over two hours after a magnitude 5.9 earthquake struck Southwest Sumba in East Nusa Tenggara, Indonesia, early Sunday morning, October 4, 2026.

According to Indonesia’s Meteorology, Climatology and Geophysics Agency (BMKG), the main earthquake struck at 5:55 AM local time, with aftershocks ranging between magnitude 1.5 and 4.3 recorded up until 8:05 AM.

BMKG revised the mainshock’s magnitude to 5.9 from an initial 6.1 estimate. The earthquake occurred at a focal depth of 30 kilometers, with its epicenter located in the sea approximately 59 kilometers southwest of Kodi, Southwest Sumba. Modeling conducted by the agency confirmed that the event posed no tsunami threat.

Structural Damage and Minor Injuries Reported

Strong tremors caused widespread alarm across Kodi, causing residents to evacuate buildings and rush outdoors.

Initial impact assessments reported by BMKG officials include:

• Casualties and Damage: As of 8:40 AM, one person was reported with minor injuries, while moderate structural damage was recorded in Pero Konda, affecting two residential homes and an Islamic primary school.
• Impact Survey: BMKG is coordinating with local disaster management agencies and the East Sumba Geophysics Station to conduct comprehensive damage assessments and monitor ongoing developments.

Expected Duration of Aftershock Activity

BMKG Earthquake Information and Tsunami Early Warning Dissemination Operations Officer Dr. Bayu Pranata explained that while two days of operational data are needed to precisely estimate aftershock decay, preliminary models indicate aftershocks could persist for less than a month.

Officials noted that the aftershock sequence is expected to conclude faster than the ongoing aftershock sequence from the August 15 Flores earthquake due to the lower magnitude of Sunday’s mainshock.

–NMT