Mount Malinao is a potentially active

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and per ...

located in the Bicol Region of the Philippines. The volcano displays strong fumarolic activity which is harnessed for generating electricity. Located on its slope is Tiwi Geothermal Power Plant, one of the first

geothermal energy Geothermal energy is the thermal energy in the Earth's crust which originates from the formation of the planet and from radioactive decay of materials in currently uncertain but possibly roughly equal proportions. The high temperature and pres ...

plant commissioned in the country.

Location

Malinao Volcano is situated between the provinces of Albay and Camarines Sur in the southeastern region of Luzon Island; about north-northwest of Mayon volcano, the most active volcano in the Philippines.

Physical features

The mountain is forested with an elevation of

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

and a base diameter of . On the summit of the volcano is a large crater with bare inner walls that are breached on the eastern side. On the lower flank this side of the predominantly andesitic volcano, is Luzon's largest solfataras and hot springs, some of which deposit

siliceous sinter Geyserite, or siliceous sinter, is a form of opaline silica that is often found as crusts or layers around hot springs and geysers. Botryoidal geyserite is known as fiorite. Geyserite is porous due to the silica enclosing many small cavities. Si ...

. Naglagbong and Jigabo are two thermal wells located on the volcano. Temperatures up to 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 250 kW 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.(2008-02-24)
"Geothermal Energy Resources in the Philippines"
JCMiras.net. Retrieved on 2011-09-24.

Classification

The Philippine Institute of Volcanology and Seismology (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 A phreatic eruption, also called a phreatic explosion, ultravulcanian eruption or steam-blast eruption, occurs when magma heats ground water or surface water. The extreme temperature of the magma (anywhere from ) causes near-instantaneous evapo ...

in the Naglagbong pool area in Tiwi on July 29, 1980, ejecting mud and rocks up to , reaching in height and distances up to . 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. Sometimes referred to as a "hum", it should not be confused with the anomalous acoustic phenomenon of the same name. The term is most commonly used to ref ...

s recorded at seismic station of the Commission on Volcanology (COMVOL) - the predecessor of PHIVOLCS - in the area.

Geyser A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in ...

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.

Mythology

The volcano is believed to be the home of the ancient Bicolano god of beasts, Asuang, who challenged the supreme god of the

Bicolano Bikol or Bicol usually refers to: *Bicol Region, the administrative region in the Philippines Bikol or Bicol may also refer to: Languages and people *Bikol languages, the languages spoken in the Bicol region in the Philippines **Albay Bikol lang ...

, Gugurang. He is worshiped alongside his friend, Bulan, the boy-god of the moon.

References

External links

Malinao
Philippine Institute of Volcanology and Seismology (PHIVOLCS) site. * {{DEFAULTSORT:Malinao Stratovolcanoes of the Philippines Subduction volcanoes Volcanoes of Luzon Mountains of the Philippines Landforms of Albay Landforms of Camarines Sur Potentially active volcanoes of the Philippines Pleistocene stratovolcanoes