UTC time | Doublet earthquake: |
---|---|
A: 1926-06-28 03:23:28 | |
B: 1926-06-28 06:15:48 | |
ISC event | |
A: 909897 | |
B: 909898 | |
USGS-ANSS | |
A: ComCat | |
B: ComCat | |
Local date | June 28, 1926 |
Local time | |
A: 10:23:28 | |
B: 13:15:48 | |
Magnitude | |
A: 6.7 Ms | |
B: 6.4 Ms | |
Depth | |
A: 15.0 km | |
B: 35.0 km | |
Epicenter | 0°37′44″S100°09′18″E / 0.629°S 100.155°E |
Fault | Great Sumatran fault |
Type | Strike-slip |
Areas affected | Sumatra, Indonesia |
Max. intensity | MMI IX (Violent) [1] |
Casualties | 411 dead |
West Sumatra, Dutch East Indies (today Indonesia) was struck by an earthquake doublet on June 28, 1926. The first earthquake occurred at 10:23 local time, with an estimated magnitude of 6.7 on the surface-wave magnitude scale with an intensity of IX (Violent) on the Modified Mercalli Intensity Scale. [2] [3] Less than three hours later, a second earthquake occurred with a magnitude of 6.4 Ms although it appears to have been less damaging. [4] [3] Three hundred and fifty-four people were killed during the first earthquake, with later shocks killing a total of 57 according to local records. [5]
The Great Sumatran fault 1900 km in length is a major strike-slip fault zone that cuts through the island of Sumatra. It accommodates the right-lateral strike-slip component of the highly oblique collision zone between the Indo-Australian plate and the Sunda plate. The Sunda megathrust carries the dip-slip component of the collision with the upper portion of the over-riding plate separated from the Sumatran fault zone by a small crustal sliver near the volcanic arc. The Great Sumatran fault is considered an example of slip partitioning. The fault runs through the north in Banda Aceh and ends in the south near the Sunda Strait. The Fault runs northwestward with ranging slip rates of 38 ± 4 mm/yr commonly cited for Aceh, however, some geodetic data believe that the elastic strain in the area is at around 16 ± 6 mm/yr and 20 ± 6 mm/yr across the parallel Aceh and Seulimeum segments from 2005 to 2010. In the Sianok segments, near the epicenter of the 1926 event, it is proposed to have slip rates of 10–11 mm/yr as well as 27–28 mm/yr for the Renun segment near Toba. The latter proposes that it has a slip rate of about 23 ± 3 mm/yr based on the deflections of the rivers nearby the young Toba tuff. The Toru segment has a slip rate of 7–14 mm/yr which also traverses near the Sibuabuali volcano. The Angkola segment, parallel to the Toru segment, observe slip-rates of about 17 ± 6 mm/yr. In the south, the slip-rates of the Musi segment have a recorded geological slip-rate of 11 ± 5 mm/yr and lastly, the slip-rates for the Kumering segment were a preliminary 6 ± 4 mm/yr, later revised to 5.5 ± 1.9 mm/yr. In total, the slip rate of the Sumatran Fault System at this latitude could be greater than the reliably constrained minimum slip rate of 7–14 mm/yr. [6]
Throughout the years, many destructive earthquakes have occurred as caused by the different segments of the Great Sumatran fault such as the 1943 Alahan Panjang earthquakes in the same region as the 1926 event, the 1994 Liwa earthquake from the Kumering segment in the south, the 1995 Kerinci earthquake from the Siulak segment, and the most recent event, the March 2007 Sumatra earthquakes from the Toru segment.
The first earthquake occurred at 10:23 am local time with a magnitude 6.7 on the surface-wave magnitude scale. [2] It was widely felt across the entirety of Western Sumatra. The earthquake produced many surface displacements and also caused a rupture from Alahan Panjang to Lake Singkarak. [7]
Just under three hours later, at 13:15 am local time, a second earthquake occurred, with the two earthquakes being interpreted as a doublet. It measured 6.4 on the surface-wave magnitude scale. [4] The second tremor was not said to have caused any major casualties and due to the limited amount of information about this second earthquake, it was overshadowed by the first earthquake. [3] The second tremor also caused a rupture from Lake Singkarak to Sipisang. [7]
The earthquake occurred during the Padang Panjang week, a market day that is held twice a week; Monday and Friday. As the local Minangkabau people in the area were doing there day-to-day activities as well as participating in the market day they would be interrupted and maybe the reason as to the many casualties from the event. Most of the buildings that would later be destroyed from the earthquake were built with mostly rocks and stones. One of the most popular icons in Bukittinggi, the Jam Gadang clock tower had tilted by 30 degrees while it was still under construction. Eyewitnesses say that the tower shook violently as the earthquake was ongoing. A report says that a total of 2,383 houses had collapsed from the first earthquake, and a further 472 houses also collapsed as a result of the aftershocks that followed after the mainshock. [3] A total of 354 people died on that day as well as an additional 57 people who died from the continuing aftershocks. [3] [5]
The earthquakes destroyed the Diniyah Putri building, an Islamic school for girls which had been founded by Rahmah el Yunusiyah in 1923. [8] The classes met in makeshift buildings for several years and Muhammadiyah approached her with an offer to take over the operation of the school and help to reestablish it; she decided not to accept the offer. [9] She toured widely in the Indies to raise money and a new permanent building was built and opened in 1928. [10]
The locals mostly remember the earthquake as a sign of doomsday and as a punishment from God to the sinners. Many Muslims regularly prayed and continued to ask for forgiveness. The earthquake resulted in an increasing number of people who began to worship Islam. However, the supposed belief eventually wore off as the years went by and the expected doomsday never occurred. [3]
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 482,286.55 km2 (182,812 mi.2), including adjacent islands such as the Simeulue, Nias, Mentawai, Enggano, Riau Islands, Bangka Belitung and Krakatoa archipelago.
The 2005 Nias–Simeulue earthquake occurred on 28 March off the west coast of northern Sumatra, Indonesia in the subduction zone of the Sunda megathrust. At least 915 people were killed, mostly on the island of Nias. It was the third most powerful earthquake since 1965 in Indonesia with a magnitude of 8.6 that caused a relatively small tsunami. Damage ranged from hundreds of buildings being destroyed in Nias to widespread power outages throughout the island of Sumatra. Following the mainshock, eight major aftershocks occurred ranging from 5.5 to 6.0 magnitudes.
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 the west coast of the island.
Padang Pariaman Regency is a regency (kabupaten) of West Sumatra, Indonesia. It has an area of 1,343.58 km2, and it had a population of 390,204 at the 2010 census and 430,626 at the 2020 census; the official estimate as at mid 2023 was 451,388 - comprising 226,435 males and 224,953 females. The regency seat is at the town of Parit Malintang. West Sumatra's capital and biggest city, Padang, is surrounded on the landward side by this regency, which includes suburbs of the city.
At 23:28 local time on June 4, 2000, southern Sumatra, Indonesia was struck by an earthquake of moment magnitude 7.9 with a maximum Mercalli intensity of VI (Strong). The event occurred off the coast near Enggano Island. There were more than 100 fatalities and up to 2,585 injuries. Over 730 aftershocks shook the area afterwards, one just eleven minutes after the mainshock.
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 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. It caused a damaging tsunami that was particularly severe near Padang, where a 150–200 t English ship was driven 1 km (0.62 mi) inland up the Arau River.
The 1984 Northern Sumatra earthquake occurred with a moment magnitude of 7.2 on November 17 at 06:49 UTC. The epicentre was located off the coast of Sumatra, near the island of Nias, where building damage was reported. This earthquake could be strongly felt in parts of Northern Sumatra, including Padang and Medan. The focal mechanism corresponded to reverse faulting.
The 1935 Sumatra earthquake occurred at 09:35 local time on 28 December. It had a magnitude of Mw 7.7 and a maximum felt intensity of VII (Damaging) on the European macroseismic scale. It triggered a minor tsunami.
The 2002 Sumatra earthquake occurred at 01:26 UTC on 2 November. It had a magnitude of 7.4 on the moment magnitude scale with an epicenter just north of Simeulue island and caused three deaths. This earthquake is regarded as a foreshock of the 2004 Indian Ocean earthquake, which had an epicenter about 60 km to the northwest.
The 1943 Alahan Panjang earthquakes occurred on June 8 and June 9 UTC in Sumatra, then under Japanese occupation. This was an earthquake doublet.
On 2 July 2013, an earthquake struck the Indonesian island of Sumatra on 2 July with a moment magnitude of 6.1 and a maximum Mercalli intensity of VI (Strong). The strike-slip earthquake killed at least 43 people and injured more than 2,500 others in the province of Aceh where approximately 4,300 homes were damaged or destroyed.
On February 20, 2008, an earthquake with a moment magnitude of 7.4 struck off the coast of Sumatra at a hypocentre depth of 26 km. The earthquake had an epicenter located on the island of Simeulue, northwest from Sinabang, a small town on the island. Three people were killed and an additional 25 seriously injured as a result of the earthquake.
The 1995 Kerinci earthquake struck near Sungai Penuh in Jambi Province on the island of Sumatra, Indonesia. It earthquake occurred at 01:18 WIB local time on October 7. The earthquake measured 6.7 Mw on the moment magnitude scale, and 6.9–7.0 Ms on the surface-wave magnitude scale. Between 84 and possibly even 100 people were killed in the earthquake. An extimated 4,000 buildings collapsed or were seriously damaged while a further 5,000 suffered some damage.
The 1843 Nias earthquake off the northern coast of Sumatra, Indonesia caused severe damage when it triggered a tsunami along the coastline. The earthquake with a moment magnitude (Mw ) of 7.8 lasted nine minutes, collapsing many homes in Sumatra and Nias. It was assigned a maximum modified Mercalli intensity of XI (Extreme).
On 25 February 2022 at 08:39 WIB, a moment magnitude (Mw ) 6.2 earthquake struck West Sumatra, Indonesia at a depth of 4.0 km (2.5 mi). Preceded by one foreshock and followed by over 200 aftershocks, the mainshock had an epicenter at the foot of Mount Talakmau in Pasaman Regency. The mainshock was the result of strike-slip faulting along a previously unidentified segment of the Great Sumatran Fault. At least 27 people died, 457 were injured, and 19,221 others were displaced. It inflicted 780 million Indonesian rupiahs (Rp) worth of damage. The heaviest damage was recorded at three villages around Mount Talakmau. Landslides and flash floods caused additional damage and casualties.
The 1933 Sumatra earthquake or Liwa earthquake occurred in West Lampung Regency, Lampung Province, Indonesia on June 25. The earthquake had an estimated surface-wave magnitude (Ms ) of 7.7 occurring at a shallow depth of 20 km. It had an epicenter onshore, devastating the city of Liwa. At least 788 people were reported killed, although the death toll may have been in the thousands. Aftershocks followed, including one which was strong enough to cause additional fatalities. The mainshock also triggered a nearby volcanic eruption two weeks later, killing some people.
Rahmah el Yunusiyah was a Dutch East Indies and Indonesian politician, educator, and activist for women's education. Born into a prominent family of Islamic scholars, she was made to leave school in order to get married as a teenager. After a few years of marriage, el Yunusiyah obtained a divorce and returned to her education.
The 1909 Kerinci earthquake struck Sumatra, Dutch East Indies on June 4 at 01:40 WIB. The shock measured Mw 7.6 and occurred along the Great Sumatran fault. Damage was extensive and great around the Kerinci area; many homes collapsed and roads were damaged. The death toll stood at between 195 and 230.
{{cite book}}
: CS1 maint: location missing publisher (link)