Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 475,807.63 km2 (182,812 mi.2), including adjacent islands such as the Simeulue, Nias, Mentawai, Enggano, Riau Islands, Bangka Belitung and Krakatoa archipelago.
The Mentawai Islands Regency are a chain of about seventy islands and islets approximately 150 kilometres off the western coast of Sumatra in Indonesia. They cover 6,033.76 km2 and had a population of 76,173 at the 2010 Census and 87,623 at the 2020 Census. Siberut at 3,838.25 square kilometres is the largest of the islands. The other major islands are Sipura, North Pagai, and South Pagai. The islands lie off the Sumatran coast, across the Mentawai Strait. The indigenous inhabitants of the islands are known as the Mentawai people. The Mentawai Islands have become a noted destination for surfing, with over 40 boats offering surf charters to international guests.
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. The Padang metropolitan area is the third most populous metropolitan area in Sumatra with a population of over 1.4 million. Padang is widely known for its Minangkabau culture, cuisine, and sunset beaches.
On 26 December 2004, at 07:58:53 local time (UTC+7), a major earthquake with a magnitude of 9.1–9.3 struck with an epicentre off the west coast of northern Sumatra, Indonesia. The undersea megathrust earthquake, known by the scientific community as the Sumatra–Andaman earthquake, was caused by a rupture along the fault between the Burma Plate and the Indian Plate, and reached a Mercalli intensity up to IX in some areas.
Nias is an island located off the western coast of Sumatra, Indonesia. Nias is also the name of the archipelago of which the island is the centre, but also includes the Batu Islands to the south-east and the small Hinako Islands to the west. Nias Island covers an area of 5,625.0 km2 (2,171.8 sq mi). It is mostly a lowland area rising to around 800 m (2,600 ft) above sea level. There were 756,338 inhabitants on the island at the 2010 Census; at the 2015 Census this had risen to 798,506 and the 2020 Census resulted in a total of 880,550. The official estimate as at mid 2022 was 902,632.
Indonesia was the first country to be seriously affected by the earthquake and tsunami created by the 2004 Indian Ocean earthquake on 26 December 2004, swamping the northern and western coastal areas of Sumatra, and the smaller outlying islands off Sumatra. Nearly all the casualties and damage took place within the province of Aceh. The time of arrival of the tsunami was between 15 and 30 minutes after the deadly earthquake.
The 2005 Nias–Simeulue earthquake occurred on 28 March off the west coast of northern Sumatra, Indonesia. At least 915 people were killed, mostly on the island of Nias. The event caused panic in the region, which had already been devastated by the massive tsunami triggered by the 2004 Indian Ocean earthquake, but this earthquake generated a relatively small tsunami that caused limited damage. It was the third most powerful earthquake since 1965 in Indonesia.
Sipora located off Sumatra in the West Sumatra Province of Indonesia, is the second-smallest and most developed of the four Mentawai Islands at only 651.55 km2. It had a population of 17,557 at the 2010 Census and 21,901 at the 2020 Census. The regency capital of the Mentawai Islands, Tuapejat, is found on Sipora. An estimated 10-15% of the original rainforest remains on this island.
Mentawai people are the native people of the Mentawai Islands about 100 miles from West Sumatra province, Indonesia. They live a semi-nomadic hunter-gatherer lifestyle in the coastal and rainforest environments of the islands and are also one of the oldest tribes in Indonesia. The Mentawai population is estimated to be about 64,000. The Mentawai tribe is documented to have migrated from Nias – a northern island – to the Mentawai islands, living in an isolated life for centuries until they encountered the Dutch in 1621. The ancestors of the indigenous Mentawai people are believed to have first migrated to the region somewhere between 2000 and 500 BCE. The Mentawai language belongs to the Austronesian language family. They follow their own animist belief system called Arat Sabulungan, that links the supernatural powers of ancestral spirits to the ecology of the rainforest. When the spirits are not treated well or forgotten, they might bring bad luck like illnesses and haunt those who forgot them. Mentawai also have very strong belief towards objects they think are holy. The people are characterized by their heavy spirituality, body art and their tendency to sharpen their teeth, a cultural practice tied to Mentawai beauty ideals. Mentawai tend to live in unison and peace with the nature around them because they believe that all things in nature have a form of spiritual essence.
The Mentawai language is an Austronesian language, spoken by the Mentawai people of the Mentawai Islands, West Sumatra, Indonesia.
An earthquake occurred on July 17, 2006 at along a subduction zone off the coast of west and central Java, a large and densely populated island in the Indonesian archipelago. The shock had a moment magnitude of 7.7 and a maximum perceived intensity of IV (Light) in Jakarta, the capital and largest city of Indonesia. There were no direct effects of the earthquake's shaking due to its low intensity, and the large loss of life from the event was due to the resulting tsunami, which inundated a 300 km (190 mi) portion of the Java coast that had been unaffected by the earlier 2004 Indian Ocean earthquake and tsunami that was off the coast of Sumatra. The July 2006 earthquake was also centered in the Indian Ocean, 180 kilometers (110 mi) from the coast of Java, and had a duration of more than three minutes.
The Pagai Island macaque, also known as the Pagai macaque or Bokkoi, is an Old World monkey endemic to the Mentawai Islands off the west coast of Sumatra. It is listed as critically endangered on the IUCN Red List due to its ever-shrinking habitat. Macaca pagensis formerly included the overall darker Siberut macaque as a subspecies, but this arrangement is polyphyletic, leading to the two being classified as separate species. Both were formerly considered subspecies of the southern pig-tailed macaque.
North Pagai is the smallest of the four principal Mentawai Islands off the west coast of Sumatra in Indonesia. It is south of Sipora and north of South Pagai Island.
The September 2007 Sumatra earthquakes were a series of megathrust earthquakes that struck the Sunda Trench off the coast of Sumatra, Indonesia, with three of magnitude 7 or greater. A series of tsunami bulletins was issued for the area. The most powerful of the series had a magnitude of 8.5, which makes it in the top 20 of the largest earthquakes ever recorded on a seismograph.
The 1833 Sumatra earthquake occurred on November 25 at about 22:00 local time, with an estimated magnitude in the range of 8.8–9.2 Mw . 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 described only as 'numerous'. The magnitude of this event has been estimated using records of uplift taken from coral microatolls.
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 a megathrust, located at a convergent plate boundary where it forms the interface between the overriding Eurasian plate and the subducting Indo-Australian plate. It is one of the most seismogenic structures on Earth, being responsible for many great and giant earthquakes, including the 2004 Indian Ocean earthquake and tsunami that killed over 227,000 people. The Sunda megathrust can be divided into the Andaman Megathrust, Sumatra(n) Megathrust and Java(n) Megathrust. The Bali-Sumbawa segment is much less active and therefore does not have the "megathrust" term associated with it.
The 2010 Mentawai earthquake occurred with a moment magnitude of 7.8 on 25 October off the western coast of Sumatra at 21:42 local time. The earthquake occurred on the same fault that produced the 2004 Indian Ocean earthquake. It was widely felt across the provinces of Bengkulu and West Sumatra and resulted in a substantial localized tsunami that struck the Mentawai Islands.
Sikakap is a sub-district on the Indonesian island of North Pagai, in the Mentawai Islands off Sumatra. The sub-district contains both Sikakap and Matobe, while Sikakap village incorporates the hamlets of Central Sikakap, East Sikakap and Sibaibai. Overall, the total population was 3,194 as of 2016. Also part of the sub-district is the Sikakap Strait between North and South Pagai, a designated Regional Marine Conservation Area. The Strait, an area of 3,960 hectares, has a coastal length of 19.79 kilometres (12.30 mi) and is a major contributor to West Sumatra's fishing industry.
The 2012 Indian Ocean earthquakes were magnitude 8.6 and 8.2 Mw undersea earthquakes that struck near the Indonesian province of Aceh on 11 April at 15:38 local time. Initially, authorities feared that the initial earthquake would cause a tsunami and warnings were issued across the Indian Ocean; however, these warnings were subsequently cancelled. These were unusually strong intraplate earthquakes and the largest strike-slip earthquake ever recorded.
The 2016 Sumatra earthquake was a 7.8 magnitude earthquake which struck on 2 March 2016 in the Indian Ocean, approximately 800 kilometers southwest of Sumatra in Indonesia. Tsunami warnings were issued for Indonesia and Australia, but were withdrawn two hours later. There were no deaths directly related to the earthquake.
