The 1797 Sumatra earthquake occurred at 22:00 local time on 10 February. It was the first in a series of great earthquakes that ruptured part of the Sumatran segment of the

Sunda megathrust The Sunda megathrust is a fault that extends approximately 5,500 km (3300 mi) from Myanmar (Burma) in the north, running along the southwestern side of Sumatra, to the south of Java and Bali before terminating near Australia. It is cap ...

. It caused a damaging

tsunami A tsunami ( ; from , ) 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 underwater explosions (including detonations, ...

that was particularly severe near

Padang Padang () is the Capital city, capital and largest city of the Indonesian Provinces of Indonesia, province of West Sumatra. It had a population of 833,562 at the 2010 CensusBiro Pusat Statistik, Jakarta, 2011. and 909,040 at the 2020 Census;Bad ...

, where a English ship was driven inland up the Arau River.

Background

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 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

, and near pure

strike-slip faulting In geology, a fault is a Fracture (geology), planar fracture or discontinuity in a volume of Rock (geology), rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust (geology ...

along the

Great Sumatran fault The Great Sumatran fault, also known as Semangko fault, is a large strike-slip fault running the entire length of the island of Sumatra. This Indonesian island is located in a highly seismic area of the world, including a subduction zone off th ...

. The major slip events on the subduction zone interface are typically of the

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,

1833 Events January–March * January 3 – The United Kingdom reasserts British sovereignty over the Falkland Islands in the South Atlantic Ocean. * February 6 (January 25 on the Greek calendar) – Prince Otto Friedrich Ludwig of Bavaria arr ...

1861 This year saw significant progress in the Unification of Italy, the outbreak of the American Civil War, and the emancipation reform abolishing serfdom in the Russian Empire. Events January * January 1 ** Benito Juárez captures Mexico Ci ...

2004 2004 was designated as an International Year of Rice by the United Nations, and the International Year to Commemorate the Struggle Against Slavery and Its Abolition (by UNESCO). Events January * January 3 – Flash Airlines Flight 60 ...

2005 2005 was designated as the International Year for Sport and Physical Education and the International Year of Microcredit. The beginning of 2005 also marked the end of the International Decade of the World's Indigenous Peoples, Internationa ...

and

2007 2007 was designated as the International Heliophysical Year and the International Polar Year. Events January * January 1 **Bulgaria and Romania 2007 enlargement of the European Union, join the European Union, while Slovenia joins the Eur ...

, 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 Events January * January 7 – Italian premier Benito Mussolini and French Foreign Minister Pierre Laval conclude an agreement, in which each power agrees not to oppose the other's colonial claims. * January 12 – Amelia Earhart ...

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 2000 was designated as the International Year for the Culture of Peace and the World Mathematics, Mathematical Year. Popular culture holds the year 2000 as the first year of the 21st century and the 3rd millennium, because of a tende ...

and

2002 The effects of the September 11 attacks of the previous year had a significant impact on the affairs of 2002. The war on terror was a major political focus. Without settled international law, several nations engaged in anti-terror operation ...

Damage

The earthquake caused the collapse or damage of many houses. The tsunami surge drove an English sailing ship of , moored in the Arau River, about inland, destroying several houses as it went. Smaller boats were driven up to 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 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 seven ...

were also reported to be affected.

Characteristics

Earthquake

The shaking lasted up to seven minutes. The magnitude of the earthquake has been estimated from uplift patterns determined from eroded coral microatolls in the range 8.6–8.8. 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 of . Modelling of tsunami effects using source parameters estimated from the uplift of microatolls, 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.

References