1797 Sumatra earthquake
Encyclopedia
The 1797 Sumatra earthquake was the first in a series of great earthquakes that ruptured part of the Sumatran segment of the Sunda megathrust
. It caused a damaging tsunami
that was particularly severe near Padang
, where a 150-200 ton English ship was driven 1 km inland up the Arau River.
between the Indo-Australian Plate
and the Eurasian Plate
. 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 along the Great Sumatran fault
. The major slip events on the subduction zone interface are typically of megathrust type. Historically, great or giant megathrust earthquakes have been recorded in 1797, 1833
, 1861
, 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 these larger events, in 1935
, 1984
, 2000
and 2002
.
were also reported to be affected.
s, provide a reasonable match to the sparse historical records.
The tsunami reports for this event are localised around Padang and it has been suggested that the tsunami may have been caused by an underwater landslide triggered by the earthquake.
Sunda megathrust
The Sunda megathrust is a fault that extends approximately 5,500 km from Myanmar in the north, running along the southwestern side of Sumatra, to the south of Java and Bali before terminating near Australia...
. It caused a damaging tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...
that was particularly severe near Padang
Padang, Indonesia
Padang is the capital and largest city of West Sumatra, Indonesia. It is located on the western coast of Sumatra at . It has an area of and a population of over 833,000 people at the 2010 Census.-History:...
, where a 150-200 ton English ship was driven 1 km inland up the Arau River.
Background
The island of Sumatra lies on the convergent plate boundaryConvergent boundary
In plate tectonics, a convergent boundary, also known as a destructive plate boundary , is an actively deforming region where two tectonic plates or fragments of lithosphere move toward one another and collide...
between the Indo-Australian Plate
Indo-Australian Plate
The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and surrounding ocean, and extends northwest to include the Indian subcontinent and adjacent waters...
and the Eurasian Plate
Eurasian Plate
The Eurasian Plate is a tectonic plate which includes most of the continent of Eurasia , with the notable exceptions of the Indian subcontinent, the Arabian subcontinent, and the area east of the Chersky Range in East Siberia...
. 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
Sunda megathrust
The Sunda megathrust is a fault that extends approximately 5,500 km from Myanmar in the north, running along the southwestern side of Sumatra, to the south of Java and Bali before terminating near Australia...
, and near pure strike-slip faulting along the Great Sumatran fault
Great Sumatran fault
The Indonesian island of Sumatra is located in a highly seismic area of the world. In addition to the subduction zone and the associated Sunda Arc off the west coast of the island, Sumatra also has a large strike-slip fault, the so-called Great Sumatran Fault, running the entire length of the island...
. The major slip events on the subduction zone interface are typically of megathrust type. Historically, great or giant megathrust earthquakes have been recorded in 1797, 1833
1833 Sumatra earthquake
The 1833 Sumatra earthquake occurred on November 25, 1833, about 22:00 local time, with an estimated magnitude in the range Mw= 8.8–9.2. It caused a large tsunami that flooded the southwestern coast of the island. There are no reliable records of the loss of life, with the casualties being...
, 1861
1861 Sumatra earthquake
The 1861 Sumatra earthquake occurred on February 16, 1861. It was the last in a sequences of earthquakes that ruptured adjacent parts of the Sumatran segment of the Sunda megathrust. It caused a devastating tsunami which led to several thousand fatalities. The earthquake was felt as far away as the...
, 2004
2004 Indian Ocean earthquake
The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred at 00:58:53 UTC on Sunday, December 26, 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is known by the scientific community as the Sumatra-Andaman earthquake...
, 2005
2005 Sumatra earthquake
The 2005 Sumatra earthquake, referred to as the Nias Earthquake by the scientific community, was a major earthquake on 28 March 2005, located off the west coast of northern Sumatra, Indonesia. Approximately 1300 people were killed by the earthquake, mostly on the island of Nias...
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 these larger events, in 1935
1935 Sumatra earthquake
The 1935 Sumatra earthquake occurred at 02:35 UTC on 28 December 1935. It had a magnitude of Mw = 7.7 and a maximum felt intensity of VIII on the mercalli intensity scale. It triggered a minor tsunami.-Tectonic setting:...
, 1984
1984 Northern Sumatra earthquake
The 1984 Northern Sumatra earthquake occurred on November 17, 1984 at 06:49 UTC. The epicenter was located off the coast of Sumatra, near the island of Nias. It was an Mw 7.2 earthquake. Building damage was reported in Nias island. This earthquake could be strongly felt in parts of Northern...
, 2000
2000 Sumatra earthquake
The 2000 Sumatra earthquake struck at 23:30 local time on June 4, 2000 off the coast of southern Sumatra, Indonesia with a magnitude of 7.9 Mw. The United States Geological Survey reported 103 fatalities, in addition to 2,174 injured people...
and 2002
2002 Sumatra earthquake
The 2002 Sumatra earthquake occurred at 01:26 UTC on 2 November. It had a magnitude of 7.3 on the moment magnitude scale with an epicenter just north of Simeulue island and caused three deaths...
.
Damage
The earthquake caused the collapse or damage of many houses. The tsunami surge drove an English sailing ship of 150-200 tons, moored in the Arau River, about 1 km inland, destroying several houses as it went. Smaller boats were driven up to 1.8 km upstream. In Air Manis, the whole town was flooded and the bodies of several people who had climbed trees to escape the surge were found the next day in the branches. Only two fatalities were reported from Padang itself but many more from Air Manis. The Batu IslandsBatu Islands
The Batu Islands are an archipelago of Indonesia located in the Indian Ocean off the west coast of Sumatra, between Nias and Siberut. The three primary islands, of approximately equal size, are Pini, Tanahmasa, and Tanahbala. There are forty-eight smaller islands, of which less than half are...
were also reported to be affected.
Earthquake
The shaking at Padang lasted one minute, reports in 1845 and 1847 said either that this was the strongest earthquake in the memory of the residents of Padang or the strongest for forty years.Tsunami
The run-up of the tsunami at Padang and the village of Air Manis is estimated to be in the range 5–10 m. Modelling of tsunami effects using source parameters estimated from the uplift of coral microatollMicroatoll
A microatoll is a discoid colony of coral, dead on the top but living around the perimeter. Growth is mainly lateral, as upward growth is limited by exposure to air. Microatolls may be up to in diameter. They are named for their resemblance to island atolls formed during the subsidence of...
s, provide a reasonable match to the sparse historical records.
The tsunami reports for this event are localised around Padang and it has been suggested that the tsunami may have been caused by an underwater landslide triggered by the earthquake.