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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 the west coast of the island. The Great Sumatran fault zone accommodates most of the strike-slip motion associated with the oblique convergence between the Indo-Australian plate and Eurasian plate The fault ends in the north near the city of Banda Aceh, which was devastated in the 2004 Indian Ocean earthquake. Geologic significance The Great Sumatran fault is part of the system where strain partitioning was first described in plate tectonics. The convergence between the Indo-Australian plate and the Sunda plate is not perpendicular to the plate boundary in this region. Instead, the two plates move at an oblique angle. Most of the convergent strain is accommodated by thrust motion at the plate boundary "megathrust" fault that defines th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault (geology)
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), crust result from the action of Plate tectonics, plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction, subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the Plane (geometry), plane that represents the fracture surface of a fault. A ''fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geological maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunda Arc
The Sunda Arc is a volcanic arc that produced the volcanoes that form the topographic spine of the islands of Sumatra, Nusa Tenggara, Java, the Sunda Strait, and the Lesser Sunda Islands. The Sunda Arc begins at Sumatra and ends at Flores, and is adjacent to the Banda Arc. The Sunda Arc is formed via the subduction of the Indo-Australian Plate beneath the Sunda and Burma plates at a velocity of 63–70 mm/year. Formation and geologic setting Mid-oceanic ridge basalts (MORB) form most of the oceanic basin south of Sunda, according to geodynamic studies. These plates began to converge in the Early Miocene. The Indo-Australian Plate is subducting beneath the Eurasian Plate with a dip angle of 49–56 degrees. The slab subducting under Java is continuous down to the lower mantle. However, the slab appears to beak apart under Sumatra Island''.'' Earthquake depth records indicate that there is no deep seismic activity in Sumatra, likely due to the age of the subducting co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismic Faults Of Southeast Asia
Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes (or generally, quakes) and the generation and propagation of elastic waves through planetary bodies. It also includes studies of the environmental effects of earthquakes such as tsunamis; other seismic sources such as volcanoes, plate tectonics, glaciers, rivers, oceanic microseisms, and the atmosphere; and artificial processes such as explosions. Paleoseismology is a related field that uses geology to infer information regarding past earthquakes. A recording of Earth's motion as a function of time, created by a seismograph is called a seismogram. A seismologist is a scientist who works in basic or applied seismology. History Scholarly interest in earthquakes can be traced back to antiquity. Early speculations on the natural causes of earthquakes were included in the writings of Thales of Miletus () ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Of Fire
The Ring of Fire (also known as the Pacific Ring of Fire, the Rim of Fire, the Girdle of Fire or the Circum-Pacific belt) is a tectonic belt of volcanoes and earthquakes. It is about long and up to about wide, and surrounds most of the Pacific Ocean. The Ring of Fire contains between 750 and 915 active or dormant volcanoes, around two-thirds of the world total. The exact number of volcanoes within the Ring of Fire depends on which regions are included. About 90% of the world's earthquakes, including most of its largest, occur within the belt. The Ring of Fire is not a single geological structure. It was created by the subduction of different tectonic plates at convergent boundaries around the Pacific Ocean. These include: the Antarctic plate, Antarctic, Nazca plate, Nazca and Cocos plate, Cocos plates subducting beneath the South American plate; the Pacific plate, Pacific and Juan de Fuca plate, Juan de Fuca plates beneath the North American plate; the Philippine Sea pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1933 Sumatra Earthquake
The 1933 Sumatra earthquake or Liwa earthquake affected southern Sumatra, Indonesia, on 25 June at 04:54 UTC+07:00, WIB. The earthquake had an estimated surface-wave magnitude () of 7.5–7.7 and occurred at a shallow depth of . It was caused by slip along a section of the seismically active Great Sumatran fault. The earthquake caused damage and hundreds of deaths in Kaur Regency, Kaur and Liwa, Indonesia, Liwa. At least 788 people were reported killed, although the death toll may have been in the thousands. Aftershocks followed, including one that caused additional fatalities. The mainshock also triggered a nearby volcanic eruption at Suwoh two weeks later, killing many people. Tectonic setting The west coast of Sumatra is dominated by the Sunda megathrust; a long convergent boundary where the Australian plate subducts beneath the Burma plate and Sunda plate at a rate of per year. Convergence along this plate boundary is Oblique subduction, highly oblique, severely deforming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1994 Liwa Earthquake
The 1994 Liwa earthquake occurred on . It was located in southern Sumatra, Indonesia. The magnitude of the earthquake was put at 6.9, 7.0, or 7.2, according to different sources."The Sumatran Fault Zone – From Source to Hazard" by D. H. Natawidjaja and W. Triyoso The earthquake caused 207 deaths and 2000 injuries. There was damage from landslides, mudslides, and fires in Lampung Province. Power outage occurred in western Lampung. Six-thousand buildings were damaged or destroyed by landslides in the Liwa area. In addition to southern Sumatra, the earthquake could be felt in western Java and Singapore. Intense smoke and gas activity was observed in the Suwoh volcanic area. The earthquake took place at the Sumatran Fault Zone. The Sumatran Fault Zone is 1,900 km long and highly segmented. It can be divided into about 20 segments. The earthquake occurred in a subparallel strand 2.5 km southwest of the principal trace of the Kumering segment. The focal mech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1995 Kerinci 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 (UTC +7) local time on October 7. The earthquake measured 6.7 on the moment magnitude scale, and 6.9–7.0 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. Earthquake The earthquake was associated with shallow strike-slip faulting along the Great Sumatran fault, instead of thrust mechanism associated with the Sunda Megathrust to the west coast. It ruptured the Siulak segment of the fault which was also involved in a magnitude 7.3 earthquake in 1909. This segment of the fault had been quiet for an unusually long period prior to the 1995 earthquake. Impact The damage occurred mainly in the valley linear to the Great Sumatran fault. Serious damage was reported north of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1943 Alahan Panjang Earthquakes
The 1943 Alahan Panjang earthquakes occurred on June 8 and June 9 UTC (June 9, 1943, local time) in Sumatra 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 list of islands by area, sixth-largest island in the world at 482,286.55 km2 (182,812 mi. ..., then under Japanese occupation. This was an earthquake doublet (the shocks occurred at the same location on consecutive days). The first mainshock occurred on June 8 at 20:42 UTC. It ruptured the Suliti segment of the Sumatran Fault Zone. The magnitude was given as 7.2, or 7.1. The second mainshock occurred on June 9 at 03:06 UTC. It ruptured the Sumani segment of the Sumatran Fault Zone and perhaps the northwestern part of the Suliti segment. The magnitude was given as 7.5, or 7.4. Alahan Panjang was damaged in the earthquakes. Right lateral offsets were reported near the town of Solok. Near the Sumani segment, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1926 Padang Panjang Earthquakes
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. Less than three hours later, a second earthquake occurred with a magnitude of 6.4 although it appears to have been less damaging. Three hundred and fifty-four people were killed during the first earthquake, with later shocks killing a total of 57 according to local records. Tectonic setting 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 se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2022 Sumatra Earthquake
On 25 February 2022 at 08:39 Time in Indonesia, WIB, a Moment magnitude scale, moment magnitude () 6.2 earthquake struck West Sumatra, Indonesia at a depth of . 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. Tectonic setting The west coast of Sumatra is dominated by the Sunda megathrust; a long convergent boundary where the Australian plate subducts beneath the Burma plate and Sunda plate at a rate of per year. The subduction zone offshore Sumatra was responsible for s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Singkarak
Lake Singkarak () is a lake in West Sumatra, Indonesia. It is located between the regencies of Tanah Datar and Solok Regency. It has an area of 107.8 km2, being approximately 21 km long and 7 km wide. The natural outlet for excess water is the Ombilin River which flows eastward to the Strait of Malacca. A hydroelectric project, however, has diverted most of the lake outflow to the Anai River which flows westward into the Indian Ocean near Padang, Indonesia, Padang. This Singkarak power station uses this water to generate power for the West Sumatra and Riau provinces. A species of fish called ''ikan bilih'' (''Mystacoleucus padangensis'') is endemic to the lake and is harvested for human consumption. A railway line, which connects Padang, Indonesia, Padang and Sawahlunto-Sijunjung, skirts the length of the lake on the eastern side. See also * List of lakes of Indonesia Notes References * * * * * Lakes of Sumatra, Singkarak Landforms of West Sumatra {{W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
March 2007 Sumatra Earthquakes
The March 2007 Sumatra earthquakes occurred near the northern end of Lake Singkarak in Sumatra, Indonesia, on March 6. The first shock in this earthquake doublet struck with a maximum Mercalli intensity of VIII (''Severe'') and the second shock that arrived two hours later had a maximum Mercalli intensity of VI (''Strong''). Earthquakes The initial quake at 10:49 (03:49 UTC) measured 6.4 on the moment magnitude scale and the second quake at 12:49 (05:49 UTC) measured 6.3. The earthquakes were felt as far away as Singapore and Malaysia, which prompted the evacuation of some buildings there. Effects Over 60 fatalities and 460 serious injuries have been reported, spread across many towns and regencies in West Sumatra. Over 43,000 houses were damaged, with over 12,000 of those severely damaged. The severe damage to other structures includes over 130 public facilities, 310 mosques, 60 government buildings, 370 schools, and 230 shops. According to the governor of West Sumatra, Agam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
