Composite Volcano

A stratovolcano, also known as a composite volcano,[1] is a conicalvolcano built up by many layers (strata) of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic explosive eruptions and effusive eruptions, although some have collapsed craters called calderas. The lava flowing from stratovolcanoes typically cools and hardens before spreading far due to high viscosity. The magma forming this lava is often felsic, having high-to-intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less-viscous maficmagma. Extensive felsic lava flows are uncommon, but have travelled as far as 15 km (9.3 mi)

Stratovolcanoes are sometimes called "composite volcanoes" because of their composite layered structure built up from sequential outpourings of eruptive materials. They are among the most common types of volcanoes, in contrast to the less common shield volcanoes. Two famous stratovolcanoes are Krakatoa, best known for its catastrophic eruption in 1883 and Vesuvius, famous for its destruction of the towns Pompeii and Herculaneum in 79 CE. Both eruptions claimed thousands of lives. In modern times, Mount Saint Helensand Mount Pinatubo have erupted catastrophically.

Existence of stratovolcanoes has not been proved on other terrestrial bodies of the solar system[3] with one exception. Their existence was suggested for some isolated massifs on Mars, e.g., Zephyria Tholus

Here are some examples of composite cone volcanoes in the Philippines :

1.Mount Pinatubo is an active stratovolcanic caldera in the Zambales Mountains, located on the tripoint boundary of the Philippine provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon.

Last eruption: 1993Elevation: 1,486 m

Location: Luzon

Region: Central Luzon

Provinces: Tarlac, Zambales, Pampanga

Did you know: The eruption of Pinatubo in 1991 was the second-largest volcanic eruption of the 1900s.

2.Mayon, also known as Mayon Volcano or Mount Mayon, is an active stratovolcano in the province of Albay in Bicol Region, on the large island of Luzon in the Philippines.

Last eruption: 18 September 2014

Elevation: 2,463 m

Location: Luzon

Cities and municipalities: Camalig; Daraga; Guinobatan; Legazpi; Ligao; Malilipot; Santo Domingo; Tabaco

Region: Bicol Region

Did you know: Like other volcanoes around the Pacific Ocean, Mayon is a part of the Pacific Ring of Fire.

3.Kanlaon, also spelled as Kanla-on or sometimes Canlaon, is an active stratovolcano on the island of Negros, Philippines. It is the highest point in Negros, as well as the whole Visayas, with an elevation of 2,465 m above sea level.

Last eruption: 2006

Elevation: 2,435 m

Volcanic arc/belt: Negros Volcanic Belt

Region: Western Visayas; Central Visayas

Provinces: Negros Occidental, Negros Oriental

Did you know: A significant increase of earthquakes at Canlaon volcano occurred between 7-10 February 2008, and the alert level was temporarily raised and a 4 km exclusion zone was established around the volcano.

4.Mount Hibok-Hibok is a stratovolcano on Camiguin Island in the Philippines. It is one of the active volcanoes in the country and part of the Pacific ring of fire.

Elevation: 1,332 m

Volcanic arc/belt: Central Mindanao Volcanic Arc

Last eruption: 1948-1953

Province: CamiguinRegion: Northern Mindanao

Did you know: Hibok-Hibok has erupted five times in modern history.