Long History Of Earthquakes In Sumenep, From The 19th Century To The Latest M6.0 Guncang Pulau Sapudi

Screenshot from the BMKG website about the earthquake in Sumenep, East Java. BETWEEN/BMKG Site Screenshots

JAKARTA - The Meteorology, Climatology and Geophysics Agency (BMKG) noted that Sumenep Regency, East Java, has had a long history of destructive earthquakes since the 19th century.

The record added to the 6.0 magnitude earthquake that shook on Tuesday, September 30 evening.

BMKG Director of Earthquake and Tsunami Daryono explained that the epicenter of the earthquake was at sea at a shallow depth of 12 kilometers, precisely at coordinates 7.35 degrees South Latitude and 114.22 degrees East Longitude or 58 kilometers southeast of Sumenep.

This earthquake includes shallow crust tectonics due to active fault activity on the seabed. The source is associated with the extension of the offshore fault of the Kendeng Zone or Madura Strait Back Arc Thrust, with an upward movement mechanism," said Daryono in Jakarta, Wednesday, October 1.

Earthquake shocks had a strong impact on Sapudi Island, with intensity reaching V'VI MMI which damaged dozens of buildings. Other areas, such as Sumenep, Pamekasan, and Surabaya, felt shocks on the MMI III scale, while Bali to Lombok were monitored on the MMI II scale.

"Temporary reports, 22 buildings suffered minor, moderate, to severe damage," said Daryono.

BMKG said the shallow hypocenter factor, soft soil conditions, and the earthquake-irresistant structure exacerbated damage on Sapudi Island. As of Wednesday afternoon, there were 117 aftershocks, with the largest magnitude 4.4.

History records that Sumenep has been rocked by at least seven destructive earthquakes. Some of them were earthquakes in 1863, the Sumenep-Sapudi earthquake in 1891, and the 1904 earthquake. In modern records, the 6.4 magnitude earthquake on October 11, 2018 killed three people, injured 34 people, and damaged 210 houses.

In addition, an earthquake with a magnitude of 4.9 on June 13, 2018 damaged a number of houses, an earthquake with a magnitude of 5.0 on March 2, 2019, resulting in six damaged houses and one injured, as well as an earthquake with a magnitude of 4.9 on April 2, 2019 causing damage to 26 houses on Raas Island.

"This note shows that the Sumenep area and its surroundings are prone to earthquakes, so people need to increase their preparedness and ensure that buildings meet earthquake-resistant standards," said Daryono.

BMKG appealed to people in East Java and its surroundings to remain alert to potential aftershocks, but not panic, and only follow official information from BMKG, BNPB, and local BPBD.