Malinao Volcano
Malinao is a volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 located in the Bicol Region
Bicol Region
The Bicol Region or Bicolandia is one of the 17 regions of the Philippines. Its regional center is Legazpi City...

 of the 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...

. The stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 has no historical eruption but displays strong fumarolic activity which is harnessed for generating electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

. Located on its slope is Tiwi Geothermal Power Plant, one of the first geothermal energy plant commissioned in the country.


Malinao Volcano is situated between the provinces
Provinces of the Philippines
The Provinces of the Philippines are the primary political and administrative divisions of the Philippines. There are 80 provinces at present, further subdivided into component cities and municipalities. The National Capital Region, as well as independent cities, are autonomous from any provincial...

 of Albay
Albay is a province of the Philippines located in the Bicol Region in Luzon. Its capital is Legazpi City and the province borders Camarines Sur to the north and Sorsogon to the south. Also to the northeast is Lagonoy Gulf....

 and Camarines Sur
Camarines Sur
Camarines Sur is a province of the Philippines located in the Bicol Region in Luzon. Its capital is Pili and the province borders Camarines Norte and Quezon to the north, and Albay to the south...

 in the southeastern region of Luzon
Luzon is the largest island in the Philippines. It is located in the northernmost region of the archipelago, and is also the name for one of the three primary island groups in the country centered on the Island of Luzon...

 Island; about 20 km (12.4 mi) north-northwest of Mayon
Mayon may refer to:*Mayon, Cornwall*Mayon Volcano*In Tamil, Mayon is a name for Krishna....

 volcano, the most active volcano in the Philippines.

Physical features

The mountain is forested with an elevation of 1548 metres (5,078.7 ft) asl
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...

 and a base diameter of 22.5 kilometres (14 mi). On the summit of the volcano is a large crater with bare inner walls that is breached on the eastern side. On the lower flank this side of the predominantly andesitic
Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...

 volcano, is Luzon
Luzon is the largest island in the Philippines. It is located in the northernmost region of the archipelago, and is also the name for one of the three primary island groups in the country centered on the Island of Luzon...

's largest solfataras and hot spring
Hot spring
A hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...

s, some of which deposit silicious sinter. Naglagbong and Jigabo are two thermal wells located on the volcano. Temperatures up to 108 °C (226.4 °F) were recorded on the fumaroles of Naglagbong.

Tiwi Geothermal Power Plant

This area was one of the first studied for generating electricity starting with a 250kW power plant in 1967. In 1979, the first of the three 110 MW geothermal power plant was commissioned that year; the other two, in 1980 and 1982. At its peak, the plant was producing a maximum of 330 MW output. Recently, the 1979 plant was decommissioned due to decrease in steam supply.


The Philippine Institute of Volcanology and Seismology
Philippine Institute of Volcanology and Seismology
The Philippine Institute of Volcanology and Seismology is a Philippine national institution dedicated to provide information on the activities of volcanoes, earthquakes and tsunamis, as well as other specialized information and services primarily for the protection of life and property and in...

 (PHIVOLCS), the government bureau that deals with volcanism in the country classifies Malinao as a potentially active volcano.

Eruptions & activities

There are no historical eruptions from Malinao which is believed to have been active from about 500,000 years ago until 60,000 years ago.

1970 earthquake swarms

There was an increase in seismicity in 1970 accompanied by rumbling noises in Malinao prompting an issue of warning that the mountain might be reactivating. The tremors detected were ranging from 1 to 5 in intensity.

Small explosion in 1980

There was a minor phreatic explosion in the Naglagbong pool area in Tiwi on July 29, 1980, ejecting mud and rocks up to 2/3 m, reaching 150 metres (492.1 ft) in height and distances up to 350 metres (1,148.3 ft). One person was injured and two buildings were damaged by the explosion. Prior to the event, as early as July 6, the area was experiencing unusual microseism
In seismology, a microseism is defined as a faint earth tremor caused by natural phenomena. The term is most commonly used to refer to the dominant background seismic noise signal on Earth, which are mostly composed of Rayleigh waves and caused by water waves in the oceans and lakes...

s recorded at seismic station of the Commision on Volcanology (COMVOL) - the predecessor of PHIVOLCS - in the area. Geyser
A geyser is a spring characterized by intermittent discharge of water ejected turbulently and accompanied by a vapour phase . The word geyser comes from Geysir, the name of an erupting spring at Haukadalur, Iceland; that name, in turn, comes from the Icelandic verb geysa, "to gush", the verb...

ing was also observed on the pool, two hours before the explosion. One theory about the cause of the explosion was water drawdown during the development of the Tiwi geothermal field.

See also

  • Active volcanoes in the Philippines
    Active volcanoes in the Philippines
    Active is commonly termed for volcanoes with historical eruptions. Moreover, the Philippine Institute of Volcanology and Seismology classify active volcanoes in the country as having erupted within historical times , with accounts of these eruptions documented by man; or having erupted within the...

  • Potentially active volcanoes in the Philippines
  • Inactive volcanoes in the Philippines
  • Pacific ring of fire
    Pacific Ring of Fire
    The Pacific Ring of Fire is an area where large numbers of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. In a horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements...

External links

  • Malinao, Philippine Institute of Volcanology and Seismology (PHIVOLCS) site.
  • Malinao at the Smithsonian Institution's Global Volcanism Program
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