2002 Mindanao earthquake
Encyclopedia
The 2002 Mindanao earthquake struck the Philippines
on March 5, 2002. The sixth most powerful earthquake of the year, it registered a magnitude
of 7.5 and was a megathrust earthquake
. It originated near the Cotabato Trench, a zone of deformation situated between the Philippine Sea Plate and the Sunda Plate
. The entire country is characterized by a high level of volcanic and seismic activity.
The earthquake was responsible for 15 deaths and roughly 100 injuries. Up to 800 buildings were damaged as a result, many from a flood generated by landslides and falling debris. A tsunami followed the earthquake.
of the earthquake was located near the Cotobato Trench; the magnitude of this megathrust earthquake
was 7.5, the sixth strongest of the year. It occurred in a zone of geologic deformation along the Sunda and Philippine Sea Plates, which converge
at a rate of 6 centimetres (2 in) each year.
The Philippines sits on several microplates between two convergent plates, the Philippine Plate
and the Eurasian Plate
. Tectonic activity in the country includes both earthquakes and volcanic eruptions. Because of subduction
of the Eurasian Plate to the west, volcanic activity occurs along the Manila Trench
and the Sulu Trench, often of powerful caliber. 13 percent of recorded eruptions in the Philippines have been deadly, as the country is responsible for the world's most deaths in volcanic eruptions. Seismicity as well has been powerful: in the last 50 years, more than half of the country's major earthquakes have reached magnitude 7.0 or greater. The earliest known major shock was in 1976, killing some 8,000 people. The Mindanao event was the fourth of seven major events since 1975.
. It spawned landslide
s in South Cotabato Province which flowed through the crater lake
on Mount Parker
, creating a widespread flood. These large flows of water surged past homes - sweeping them away - and enveloped at least 9 districts of the Province. It also created local tsunami
s reaching a maximum height of 3 metres (10 ft) at Kiamba
, Maitum
and Palimbang
. The earthquake was powerful enough to knock over concrete walls and fences. Sending debris raining down on people, the earthquake rocked homes and sent objects flying off of shelves. The earthquake was responsible for the destruction of a major road.
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
on March 5, 2002. The sixth most powerful earthquake of the year, it registered a magnitude
Moment magnitude scale
The moment magnitude scale is used by seismologists to measure the size of earthquakes in terms of the energy released. The magnitude is based on the seismic moment of the earthquake, which is equal to the rigidity of the Earth multiplied by the average amount of slip on the fault and the size of...
of 7.5 and was a megathrust earthquake
Megathrust earthquake
Megathrust earthquakes occur at subduction zones at destructive plate boundaries , where one tectonic plate is forced under another. Due to the shallow dip of the plate boundary, which causes large sections to get stuck, these earthquakes are among the world's largest, with moment magnitudes ...
. It originated near the Cotabato Trench, a zone of deformation situated between the Philippine Sea Plate and the Sunda Plate
Sunda Plate
The Sunda Plate is the tectonic plate on which the majority of Southeast Asia is located. It was formerly considered a part of the Eurasian Plate, but GPS measurements have confirmed its independent movement at 10 mm/yr eastward relative to Eurasia...
. The entire country is characterized by a high level of volcanic and seismic activity.
The earthquake was responsible for 15 deaths and roughly 100 injuries. Up to 800 buildings were damaged as a result, many from a flood generated by landslides and falling debris. A tsunami followed the earthquake.
Geology
The epicenterEpicenter
The epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates...
of the earthquake was located near the Cotobato Trench; the magnitude of this megathrust earthquake
Megathrust earthquake
Megathrust earthquakes occur at subduction zones at destructive plate boundaries , where one tectonic plate is forced under another. Due to the shallow dip of the plate boundary, which causes large sections to get stuck, these earthquakes are among the world's largest, with moment magnitudes ...
was 7.5, the sixth strongest of the year. It occurred in a zone of geologic deformation along the Sunda and Philippine Sea Plates, which converge
Convergent 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...
at a rate of 6 centimetres (2 in) each year.
The Philippines sits on several microplates between two convergent plates, the Philippine Plate
Philippine Plate
The Philippine Sea Plate is a tectonic plate comprising oceanic lithosphere that lies beneath the Philippine Sea, to the east of the Philippines...
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...
. Tectonic activity in the country includes both earthquakes and volcanic eruptions. Because of subduction
Subduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...
of the Eurasian Plate to the west, volcanic activity occurs along the Manila Trench
Manila Trench
The Manila Trench is an ocean trench in the South China Sea, west of the Philippines. It reaches a depth of about 5,400 m, in contrast with the average depth of the South China Sea of about 1,500 m...
and the Sulu Trench, often of powerful caliber. 13 percent of recorded eruptions in the Philippines have been deadly, as the country is responsible for the world's most deaths in volcanic eruptions. Seismicity as well has been powerful: in the last 50 years, more than half of the country's major earthquakes have reached magnitude 7.0 or greater. The earliest known major shock was in 1976, killing some 8,000 people. The Mindanao event was the fourth of seven major events since 1975.
Damage and casualties
Killing 15 and injuring roughly 100, the earthquake damaged as many as 800 buildings throughout the southern and central parts of MindanaoMindanao
Mindanao is the second largest and easternmost island in the Philippines. It is also the name of one of the three island groups in the country, which consists of the island of Mindanao and smaller surrounding islands. The other two are Luzon and the Visayas. The island of Mindanao is called The...
. It spawned landslide
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
s in South Cotabato Province which flowed through the crater lake
Crater lake
A crater lake is a lake that forms in a volcanic crater or caldera, such as a maar; less commonly and with lower association to the term a lake may form in an impact crater caused by a meteorite. Sometimes lakes which form inside calderas are called caldera lakes, but often this distinction is not...
on Mount Parker
Mount Parker (Cotabato)
Mount Parker, locally known as Melibengoy, is a stratovolcano on Mindanao island in the Philippines . It is located in the province of South Cotabato, 30 kilometers west of General Santos City and 44 kilometers south of Koronadal City.The volcano's English name is taken from an American...
, creating a widespread flood. These large flows of water surged past homes - sweeping them away - and enveloped at least 9 districts of the Province. It also created local 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...
s reaching a maximum height of 3 metres (10 ft) at Kiamba
Kiamba, Sarangani
thumb|Sea Foods, the second biggest income earner.Kiamba is a 2nd class municipality established 1947, in the province of Sarangani, Philippines...
, Maitum
Maitum, Sarangani
Maitum is a 2nd class municipality in the province of Sarangani, Philippines. According to the latest census, it has a population of 37,054 people in 7,640 households....
and Palimbang
Palimbang, Sultan Kudarat
Palimbang is a 3rd class municipality in the province of Sultan Kudarat, Philippines. According to the 2000 census, it has a population of 43,742 people in 8,191 households.-Barangays:Palimbang is politically subdivided into 40 barangays.* Akol...
. The earthquake was powerful enough to knock over concrete walls and fences. Sending debris raining down on people, the earthquake rocked homes and sent objects flying off of shelves. The earthquake was responsible for the destruction of a major road.