The 1935 Sumatra earthquake occurred at on 28 December. It had a magnitude of 7.7 and a maximum felt intensity of VIII (''Severe'') on the
Mercalli intensity scale. It triggered a minor
tsunami
A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater exp ...
.
Tectonic setting
The island of Sumatra lies on the
convergent plate 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 ...
between the
Indo-Australian Plate
The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and the surrounding ocean and extends northwest to include the Indian subcontinent and the adjacent waters. It was formed by the fusion of the Indian an ...
and the
Eurasian Plate
The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...
. The convergence between these plates is highly oblique near Sumatra, with the displacement being accommodated by near pure
dip-slip faulting along the subduction zone, known as the
Sunda megathrust, and near pure
strike-slip faulting
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
along the
Great Sumatran fault
The Indonesian island of Sumatra is located in a highly seismic area of the world. In addition to the subduction zone off the west coast of the island, Sumatra also has a large strike-slip fault, the Great Sumatran Fault also known as Semangko ...
. The major slip events on the subduction zone interface are typically of
megathrust
Megathrust earthquakes occur at convergent plate boundaries, where one tectonic plate is forced underneath another. The earthquakes are caused by slip along the thrust fault that forms the contact between the two plates. These interplate earthqu ...
type. Historically, great or giant megathrust earthquakes have been recorded in
1797
Events
January–March
* January 3 – The Treaty of Tripoli, a peace treaty between the United States and Ottoman Tripolitania, is signed at Algiers (''see also'' 1796).
* January 7 – The parliament of the Cisalpine ...
,
1833,
1861
Statistically, this year is considered the end of the whale oil industry and (in replacement) the beginning of the petroleum oil industry.
Events
January–March
* January 1
** Benito Juárez captures Mexico City.
** The first stea ...
,
2004,
2005 and
2007, most of them being associated with devastating tsunamis. Smaller (but still large) megathrust events have also occurred in the small gaps between the areas that slip during the larger events, in 1935,
1984
Events
January
* January 1 – The Bornean Sultanate of Brunei gains full independence from the United Kingdom, having become a British protectorate in 1888.
* January 7 – Brunei becomes the sixth member of the Association of Southeas ...
,
2000
File:2000 Events Collage.png, From left, clockwise: Protests against Bush v. Gore after the 2000 United States presidential election; Heads of state meet for the Millennium Summit; The International Space Station in its infant form as seen from S ...
and
2002.
Damage
The
Batu Islands and the neighbouring coast of
Sumatra were the most affected areas. The lighthouse on Bodjo island was damaged and cracks appeared in the hill that it stands on. Several houses were destroyed at Pulu Tello. The islands of Tanahbala and Sigata showed evidence of uplift, with low-lying areas no longer flooded at high tide. Near
Padang
Padang () is the capital and largest city of the Indonesian province of West Sumatra. With a Census population of 1,015,000 as of 2022, it is the 16th most populous city in Indonesia and the most populous city on the west coast of Sumatra. Th ...
power and telephone lines swayed, with some lines being cut. Some huts collapsed at
Sibolga
Sibolga (formerly sometimes Siboga) is a city and a port located in the natural harbor of Sibolga Bay on the west coast of North Sumatra province, in Indonesia.
It is located on the western side of North Sumatra, facing the Indian Ocean and is ...
, although there were no reported casualties.
Characteristics
The earthquake is thought to have occurred on the plate interface at a depth of about 28 km. The estimated source parameters for the earthquake are 65 km length, 30 km width with a maximum displacement of 3 m.
Such a rupture zone has a predicted pattern of uplift and subsidence and this has been found to be consistent with paleogeodetic records taken from coral
microatolls around the Batu Islands.
See also
*
List of earthquakes in 1935
*
List of earthquakes in Indonesia
References
External links
*
{{DEFAULTSORT:1935 Sumatra Earthquake
Earthquakes in Sumatra
Sumatra Earthquake, 1935
Earthquakes in Indonesia
Sumatra Earthquake
Sumatra Earthquake
History of Sumatra
1935 disasters in Asia
1935 disasters in Oceania
20th-century disasters in Indonesia