Activity of Pavlof, Colima, Villarica, Rincon de La Vieja, Poas and Krakatau.

An increase in the level of activity of Pavlof Volcano, characterized by low frequency tremors and a vigorous steam plume justified a higher alert level and a color code adjustment for aviation: Yellow / advisory.

This does not mean that an eruption is possible or imminent, but past eruptions of Pavlof have occurred without many warning signs.

Pavlof is a stratovolcano covered with snow and ice, located at the southwestern tip of the Alaskan Peninsula.

Source: Alaska Volcano Observatory / USGS

The increase in the level of activity of Colima in Mexico is confirmed, with the seismographic recording of an exhalation on May 15 at 2:58.

The alert level is amarillo, with an exclusion zone of 8 km.

Source: Cenapred

In Chile, Villarica has had sporadic Strombolian lava fountains in the past five months.

They result from the explosion of enormous bubbles of gas rising from the depths of the magmatic column; in the upper segment of the chimney, they push and compress the lava through a small hole in the bottom of the crater, according to the principle "gas-piston".

On May 14, the fountains are particularly spectacular, more than 20-40 meters wide and over 70 meters high above the edge of the crater. The temperature of the lava is estimated to be above 1,000 ° C (explanations by Werner Keller / POVI)

Source: Werner Keller / POVI

The weekly bulletin on Costa Rica's volcanoes details the activity of Rincon de la Vieja and Poas.

At Rincon de La Vieja, LP earthquakes were numerous on May 10th and 11th. And on May 11, a phreatic eruption began at 7:19, and lasted 7 minutes, expelling acid lake sediments and ashes; a plume of steam and magmatic gas rose to about 600 meters.

Caution is advised near drainages, due to the risk of primary lahars, or in case of rains, of secondary lahars, caused by remobilization of ashes accumulated by previous eruptions.

In Poas, when visibility permits, we can observe a plume of gas and vapor, and incandescence during the night.

A visit to the RSN on May 11 revealed a vigorous degassing of the mouth A, and a slightly smaller exit to the mouth B. An accumulation of gas, mainly H₂S, because of the low wind, justified the closing of the watchtower for a few minutes

Source: Red Sismologica Nacional - https://bit.ly/2VsKq0C

In Indonesia, Anak Krakatau presented an eruptive episode on May 15 at 15:58 WIB, recorded on the seismogram with an amplitude of 43 mm and a duration of 41 seconds. The height of the plume could not be observed.

Sentinel 2 allowed a clear observation of the volcano the same day ... the morphology of the west flank is slowly changing.

The alert level remains at 2, with a radius of 2 km around the crater.

Sources: PVMBG & Sentinel 2