The 1917 Bali earthquake occurred at 06:50 local time on 21 January (23:11 on 20 January
UTC). It had an estimated magnitude of 6.6 on the
surface wave magnitude scale and had a maximum perceived intensity of IX (''Violent'') on the
Mercalli intensity scale. It caused widespread damage across
Bali, particularly in the south of the island. It triggered many landslides, which caused 80% of the 1,500 casualties.
Tectonic setting
The island of Bali forms part of the
Sunda Arc, which formed above the
convergent boundary
A convergent boundary (also known as a destructive boundary) is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other, a process known as subduction. The subduction zone can be defined by a ...
where the
Australian Plate
The Australian Plate is a major tectonic plate in the eastern and, largely, southern hemispheres. Originally a part of the ancient continent of Gondwana, Australia remained connected to India and Antarctica until approximately when India broke ...
is
subducting
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...
beneath the
Sunda Plate. The rate of convergence across the line of the
Sunda–Java Trench is 7.5 cm per year. Eastwards from Bali, the Sunda Arc is also being thrust over the Bali and Flores
back-arc basins on a series of south-dipping
thrusts.
Focal mechanisms for earthquakes near Bali are dominantly thrust sense on both the subduction interface and the system of thrust faults to the north.
Earthquake
The earthquake was recorded by the Wiechert
seismograph at Batavia (now
Jakarta), which indicated an epicenter southeast of the island. There was a general decrease in the intensity of the shaking from the south of the island to the north. The earthquake was also felt on eastern
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...
and
Sumbawa
Sumbawa is an Indonesian island, located in the middle of the Lesser Sunda Islands chain, with Lombok to the west, Flores to the east, and Sumba further to the southeast. Along with Lombok, it forms the province of West Nusa Tenggara, but th ...
, and particularly strongly on
Lombok
Lombok is an island in West Nusa Tenggara province, Indonesia. It forms part of the chain of the Lesser Sunda Islands, with the Lombok Strait separating it from Bali to the west and the Alas Strait between it and Sumbawa to the east. It is ...
. A small tsunami was observed on the southeastern coast of Bali, but caused no damage.
Damage
The earthquake triggered many landslides. There were an estimated 1,500 casualties, of which 80% were a result of the landslides. 2,431 temples were destroyed or severely damaged,
including the
Pura Ulun Danu Batur
Pura Ulun Danu Batur (also known as "Pura Batur" or "Pura Ulun Danu") is a Hindu Balinese temple located in the island of Bali, Indonesia. As one of the Pura Kahyangan Jagat, Pura Ulun Danu Batur is one of the most important temples in Bali whi ...
.
Gallery
See also
*
List of earthquakes in 1917
*
List of earthquakes in Indonesia
References
{{Earthquakes in Indonesia
Earthquakes in Indonesia
1917 earthquakes
1917 tsunamis
January 1917 events
History of Bali
Tsunamis in Indonesia
1917 disasters in Asia
1917 disasters in Oceania
20th-century disasters in Indonesia