9 Facts about the Garut Earthquake According to BMKG, One of which is the Wide Spectrum

JAKARTA – The Meteorology, Climatology and Geophysics Agency (BMKG) reveals facts about earthquake M6.2 centered in the Indian Ocean, south of West Java, Saturday (27/4/2024) at 23.29.47 WIB. One of them, the earthquake had a broad spectrum covering the southern region of Central Java to East Java.

Garut Earthquake M6.2 strength feels strong enough to reach Jakarta. This earthquake also caused 110 houses to be damaged and 8 people were injured. Head of the BNPB Disaster Data, Information and Communication Center, Abdul Muhari detailed the level of damage to houses, including 3 house units heavily damaged (RB), 21 house units moderately damaged (RS), 34 house units lightly damaged (RR), 11 house units affected , and 41 housing units were damaged.

9 Facts about the Garut Earthquake

1. Based on the Sea

Head of the BMKG Earthquake and Tsunami Center, Daryono, in his statement, Monday (29/4/2024), said that the earthquake was centered in the sea (Indian Ocean) at a distance of 156 km southwest of Garut Regency with a hypocenter depth of 70 km.

2. Medium Depth Earthquake

According to Daryono, this type of mid-depth earthquake was triggered by rock deformation in the Indo-Australian Plate which was subducted under the Eurasian Plate south of West Java, with an earthquake source mechanism of shear-upward movement (oblique thrust).

3. Earthquakes in Plates

Daryono said that experts commonly call it an intra-slab earthquake due to the breaking of rocks in the plate slab. One of the features of intra-slab earthquakes is that they are able to radiate earthquake shocks (ground motion) that are more powerful than other earthquakes from other sources.

4. Not a Megatrust Earthquake

Daryono emphasized that the M6.2 earthquake was not a megathrust earthquake, which was proven by cross-section data of the hypocenter (cross-section) which showed that the hypocenter of the earthquake was located within the slab of the Indo-Australian Ocean Plate.

5. Only Followed by One Aftershock

The main earthquake was only followed by one aftershock (aftershock), with a magnitude of 3.1 which occurred on April 27 2024 at 23.45.13 WIB.

6. Poor Aftershocks

Daryono explained that the main earthquake was lacking in aftershocks because the slab rock of the Indo-Australian Ocean Plate was homogeneous, elastic and not easily brittle (ductile).

7. Destructive in nature

The Garut earthquake is destructive. The earthquake shook strongly in Tegalbulued, Pamulihan, Sukanagara, Cempaka, Langkaplancar and Lembang with an intensity scale of V MMI and caused damage in Tasikmalaya, Garut, Sukabumi, and Ciamis districts.

8. Broad Spectrum

Because the hypocenter was deep, this earthquake had a wide spectrum covering the areas of Kebumen, Banyumas, Cilacap and Purwokerto, Bantul, Sleman, Kulonprogo, Trenggalek, and Malang.

9. No Tsunami Potential

The results of Tide Gauge monitoring belonging to the Geospatial Information Agency (BIG) at Tasikmalaya and Cilacap beaches did not show any sea level anomalies. The earthquake that occurred was not able to cause disruption of the sea water column/tsunami, one of which was because the hypocenter was quite deep.

(abd)