BMKG: Earthquake In Alaska Has No Significant Impact On Indonesian Territory

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JAKARTA - An earthquake with a magnitude of 8.1 in the Perryville region, Alaska, United States, Thursday, July 29 at 13:15 p.m. Indonesian western time (WIB) triggered a small tsunami.

The Meteorology, Climatology, and Geophysics Agency (BMKG) stated that this natural disaster did not have a significant impact on Indonesian territory.

"In Alaska, several evacuation orders sirens were sounded. However, because the results of sea-level monitoring only recorded a small tsunami that would not have an impact, the tsunami early warning was terminated", said BMKG Earthquake and Tsunami Mitigation Coordinator Daryono in Jakarta, reported by Antara, Thursday, July 29.

The Pacific Tsunami Warning Center (PTWC) conveyed information that an earthquake in Alaska has the potential to cause a small tsunami of fewer than 0.3 meters in Indonesian territory.

According to the BMKG, based on modeling results, a tsunami with an insignificant height, less than five cm, will arrive in Indonesian territory, to be precise in northern Papua, on July 30, 2021, at 00:10 a.m. WIB.

"Based on the results of this modeling, the BMKG did not issue a tsunami early warning for the territory of Indonesia, for that the public is advised to remain calm and not to easily believe in issues that cannot be justified", said Daryono.

He explained that based on the location of the epicenter and the depth of the hypocenter, the earthquake that occurred in the Alaska region on Thursday was a shallow earthquake due to plate subduction activity in the Alaskan-Aleutian megathrust zone.

The Alaskan-Aleutian subduction is known to be seismically active with a westward movement rate of 57-61 mm of the Pacific Plate per year.

This plate subduction system is a powerful earthquake generator in the Alaska Peninsula region, which has triggered several powerful earthquakes and tsunamis.

Major earthquakes that triggered tsunamis that occurred in the Alaskan region and sourced from the Aleutian subduction zone occurred in 1938 (magnitude 8.3), in 1946 (magnitude 8.1), in 1956 (magnitude 8.6), 1965 (magnitude 8.6), and 1965 (magnitude 8.7), 1964 (magnitude 9.2), and 1986 (magnitude 8.0).

After an earthquake with a magnitude of 8.1 that occurred in the Alaska region on Thursday at 13.15 p.m. WIB, until 16.00 p.m. WIB, there have been more than 25 aftershocks with a magnitude of less than 6.0.