Costa Rica’s Poás volcano continues to simmer

March 14, 2012 – COSTA RICA – During February, Poás activity consisted in strong high-temperature fumarolic activity and sporadic small phreatic explosions, reported by park rangers. The latest monthly bulletin of Costa Rica’s volcano observatory OBSICORI published a more detailed summary of Poás’ activity during February summarized as follows: The ultra-acid crater lake had a greenish-gray color with sporadic convection cells visible in the central part carrying sulfur in suspension. Lake temperature were measured at 44° C, which is a value significantly lower than those measured during most of 2009-2011. The pH value of the lake water was measured at 0.01, slightly “less” acidic than during November 2011 (pH -0.4). The lake volume continued to decrease and its level dropped by 1.16 m between 25 Jan and 24 Feb. Concentrations of sulphate and chlorine increased. The composite pyroclastic cone (the “dome”) has high-temperature fumarolic activity and a strong emissions of blue gas (SO2). Fumarolic activity in the northwest sector of the “dome” had temperatures between 685 and 725°C. In the northern part of the “dome”, temperatures were ranging between 640 and 727°C (at accessible points). –Volcano Discovery