|TAAL VOLCANO BULLETIN 31 May 2011 8:00 A.M.|
|Tuesday, 31 May 2011 07:05|
Taal Volcano’s (14.0000°N, 120.9833°E) seismic network recorded thirty one (31) volcanic earthquakes during the past 24 hours. Five of these events were felt at varying intensities ranging from Intensity I – II by residents of Pira-piraso and Calauit located at northeast and southeast sectors of the volcano. One event which occurred at 11:41 A.M. was felt at Intensity I, while four (4) events which occurred at 7:26 A.M., 9:28 A.M., 9:30 A.M. and 6:16 P.M. were felt at Intensity II. These felt events were reportedly accompanied with rumbling sounds.
Field measurements conducted on 24 May 2011 at the eastern sector inside the Main Crater Lake showed that the water temperature slightly increased from 32.5°C to 32.8°C, and the pH value became more acidic decreasing from 2.83 to 2.67. Results of the ground deformation survey (precise leveling) conducted around the Volcano Island last 26 April - 03 May 2011 showed that the volcano edifice inflated slightly relative to the 05-11 April 2011 survey. Measurement of carbon dioxide (CO2) gas emission rates last 03-04 May 2011 at Taal Main Crater Lake yielded a value of 2,057 tonnes per day (t/d) which is twice the background level.
Alert Level 2 is still in effect over Taal Volcano, with the interpretation that magma has been intruding towards the surface, as manifested by the continuing high emission rate of CO2 being released in the Main Crater Lake and sustained seismic activity. Hence, PHIVOLCS advises the public that the Main Crater, Daang Kastila Trail and Mt. Tabaro (1965-1977 Eruption Site) are strictly off-limits because sudden hazardous steam-driven explosions may occur and high concentrations of toxic gases may accumulate. Breathing air with high concentration of toxic gases can be lethal to human, animals and even cause damage to vegetation. In addition, it is reminded that the entire Volcano Island is a Permanent Danger Zone (PDZ), and permanent settlement in the island is strictly not recommended. DOST-PHIVOLCS is closely monitoring Taal Volcano’s activity and any new significant development will be immediately relayed to all concerned.