Ubinas volcano enters new eruptive phase, Peru

Peru's Ubinas volcano erupted at 08:32 UTC on April 8, 2015 covering nearby villages with a thin layer of ash.

Emissions of steam and gasses reached an estimated altitude of 5.1 km, Buenos Aires VAAC reports.

Ash fall was expected within 25 km to the southeast. Experts advised local population to protect themselves with masks and goggles and to protect water resources and food to prevent contamination.

Head of the IGP of Moquegua, encouraged the authorities to remain on alert as volcano activity may increase in the coming hours. 

Image credit: IGP

Seismicity at Ubinas significantly increased since late March with more tremors related to movement of fluids and magma migration, suggesting a new eruptive phase has started.

The volcano was quiet since November 23, 2014 when two explosions sent ash plumes up to 2.5 km.

Geologic summary

A small, 1.4-km-wide caldera cuts the top of Ubinas, Peru's most active volcano, giving it a truncated appearance. It is the northernmost of three young volcanoes located along a regional structural lineament about 50 km behind the main volcanic front of Perú. The growth and destruction of Ubinas I was followed by construction of Ubinas II beginning in the mid-Pleistocene. The upper slopes of the andesitic-to-rhyolitic Ubinas II stratovolcano are composed primarily of andesitic and trachyandesitic lava flows and steepen to nearly 45 degrees.

The steep-walled, 150-m-deep summit caldera contains an ash cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-avalanche deposits from the collapse of the SE flank about 3700 years ago extend 10 km from the volcano. Widespread plinian pumice-fall deposits include one of Holocene age about 1000 years ago. Holocene lava flows are visible on the flanks, but historical activity, documented since the 16th century, has consisted of intermittent minor-to-moderate explosive eruptions. (GVP).

Featured image: NASA Terra/MODIS acquired on April 8, 2015.