Sunday 6 April 2014

Major eruption on Mount Tungurahua.

Mount Tungurahua, a stratovolcano (a 'conventional' cone-shaped volcano, the sort you see in Hollywood movies) located in the Sangay National Park in Ecuador, overlooking the town of Baños de Agua Santa, erupted suddenly at about 6.10 pm local time (about 11.10 pm GMT) on Friday 4 April 2014, producing a column of ash rising 10 km above the summit of the volcano. The initial eruption was followed by a number of smaller eruptions and earthquakes.

The ash column over Mount Tungurahua on Friday 4 April 2014. Carlos Campana/Reuters.

Tungurahua has been intermittently active since 1999 (prior to which it had been inactive for about 75 years), with major eruptions in August 2006, February 2008, May 2010, December 2010 and April 2011. The 2006 eruption killed seven people; two volcanologists and a local family

The current Tungurahua volcano is the third on the site, referred to by volcanologists as Tungurahua III. The first volcano on the site, Tungurahua I, built up and then collapsed some time in the Mid-Pleistocene. This was followed by Tungurahua II, which started to grow about 14 000 years ago, then collapsed about 3000 years ago. The current volcano has been growning since this time, and lies within the caldera of Tungurahua II.


The approximate location of Mount Tungurahua. Google Maps.

Like all South American volcanoes Tungurahua owes its existence to the subduction of the Nazca Plate (which underlies the southeast Pacific) beneath South America. The Nazca Plate is being pushed from the east and forced down into the Earth's interior beneath South America. As it sinks rocks in the crust melt, and the lighter portions of it rise up through the overlying South American Plate to form volcanoes at the surface. These are dotted throughout the Andes Mountains; a range of mountains that is formed by a mixture of volcanism and crumpling of the South American Plate where is is forced against the Nazca Plate.

The subduction of the Nazca Plate beneath the South American Plate. Marot et al. (2012).

See also...

 Further eruptions on Mount Tungurahua.

200 people evacuated after eruption on Tungurahua.

New eruptions on Mount Tungurahua, Ecuador. November 2011.

Follow Sciency Thoughts on Facebook.