Latest news from Poas volcano:
Thursday, Aug 22, 2013
A series of small phreatic eruptions occurred on 20 August at the crater lake. The first occurred at 09:55 (local time), ejecting mud and water to 2-3 m height, and a second one, more powerful, at 11:16 reached heights of 10-20 m. [more]
Poas volcanoPoás is one of Costa Rica´s most active volcanoes, and one of its most frequently visited and prominent ones. It contains a green acid crater lake and during some of its frequent phreatic eruptions, water from the lake is ejected like a geyser.
Background:The broad, well-vegetated edifice of Poás has three craters in a N-S line. The 2708-m-high basaltic-to-dacitic complex stratovolcano is cut by a N-S-trending fissure that extends to the lower northern flank, where a parasite volcano (the Congo stratovolcano) and several explosion craters, or maars, most of them lake-filled, have been created.
Poás has two summit crater lakes. The southermost one, Botos, is cold, clear has not eruptied for about 7500 years. The other crater lake is geothermally heated and -after Kawah Ijen in Indonesia - is probably the world's second most acidic natural lake. Its pH is near zero.
Source: GVP, Smithsonian Institution