Calbuco Volcano Eruption (April 2015)

Calbuco volcano (Chile) erupts – amazing video

The Calbuco volcano in southern Chile has erupted twice and the people have been evacuated. It is the first eruption of the stratovolcano in 42 years; results in huge ash cloud over mountainous area in south of Chile.

The amazing footage from the area shows a huge column of lava and ash being sent several kilometers into the air.

Last erupted in 1972, the Calbuco volcano considered one of the top three most potentially dangerous of Chile’s 90 active volcanoes. It has had at least 10 eruptions since 1837. The most recent eruption was on April 22, 2015.

The authorities have declared a red alert and evacuated more than 4,000 people within a 20km (12 mile) radius.

The eruption also caused airline flight cancellations and evacuation of the surrounding countryside. A flow of lava was reported into Chapo Lake on the same day.

The Chilean administration, wich had faced two major catastophes the prevous months -a wildfire in Valparaíso and a flood in northern towns- declared exceptional constitutional restrictions the same day. Air Force General Jorge Gebauer Bittner was appointed as Chief of Defense in the catastrophe zone. On April 23rd, at 01:00 a new, more energic pulse started.

Calbuco Volcano (Chile) erupts (April 22, 2015)
Calbuco Volcano (Chile) erupts (April 22, 2015). Photo: Reuters. It is a very explosive andesite volcano whose lavas usually contain 55-60% SiO2. It underwent edifice collapse in the late Pleistocene, producing a volcanic debris avalanche that reached the lake.

Calbuco volcano is a stratovolcano, also known as a composite volcano, a conical volcano 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 mafic magma. 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 AD. Both eruptions claimed thousands of lives.

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

Sources

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