Sumatra Island Is Prone To Earthquakes, This Is The Source

Illustration (Photo: Antara)

JAKARTA - Sumatra Island is an earthquake-prone area and has the potential to face earthquake threats from many sources.

BMKG Head of Earthquake and Tsunami Mitigation Daryono, the threat of the island of Sumatra does not only come from the Megathrust Zone, the Mentawai Fault, and the Great Sumatra Fault on the mainland.

"However, strong earthquakes can also originate in the Fracture Zone Investigator near the subduction plate in the west of Sumatra," said Daryono in Jakarta, quoted by Antara, Tuesday, November 17.

He explained that this was seen from the activity of the earthquake source on Tuesday, at 08.44.07 WIB which shook Tuapejat, Mentawai Regency, West Sumatra with a magnitude of 6.3.

This earthquake includes a strong earthquake having an "update" magnitude of 6.0 centered in the sea with coordinates of 2.90 latitude and 99.07 east longitude, at a distance of 112 km southwest of Tuapejat City, Mentawai Islands, West Sumatra.

The earthquake that occurred Tuesday morning was a shallow earthquake. The "update" analysis shows that this earthquake is hypocenter at a depth of 31 km, which means that the epicenter of this earthquake is inside the Indo-Australian Plate and not on the Eurasian Plate.

Earthquake shocks are felt in a wide area, such as Padang, Painan, Sipora, Solok, Mentawai, Sipora, Padang Panjang, Bukittinggi, Pariaman, Kepahiang, Pasaman, Kerinci, Payakumbuh, and South Solok.

The earthquake was not an earthquake caused by plate collision activity in the megathrust zone. Earthquakes due to plate collisions usually have a thrust fault source.

However, the earthquake triggered by a transform fault has a source mechanism in the form of a transform fault which appears to be related to the earthquake source of the shear fault on the Indo-Australian Plate in the Indian Ocean, known as the Investigator Fracture Zone.

"This earthquake has no potential for a tsunami because its strength is still below 7.0 as well as the source mechanism in the form of a shear fault," he said.

The longitudinal IFZ structure in the Indian Ocean is relatively north-south trending and at the northern end of the IFZ adjacent to the Sumatra Subduction Zone.

Daryono said that an earthquake like this had occurred in the Indian Ocean west of Aceh on April 12, 2012, measuring 8.6 and 8.1, both of which were another example of an earthquake related to the source of the earthquake Investigator Fracture Zone (IFZ).