Taal Volcano Alert Level 2 Bulletin (April 09, 2011)

This is a notice for the raising of the alert status of Taal Volcano (14°00.1’N, 120°59.6’E) from Alert Level 1 to Alert Level 2.
Following the issuance of the volcano advisory on 31 March 2011, the monitored parameters have shown significant changes as indicated by the following observations:
  1. Seismic activity at Taal Volcano continued to worsen. The number of volcanic earthquakes detected gradually rose and the depths of the plotted quakes are becoming shallow (1.0-4.0 km).  There is also an increase in the number of perceptible quakes. During the past 24 hours, two (2) quakes were felt at the Volcano Island with Intensities ranging from II to III and one of them was accompanied by rumbling sounds. Twenty-one (21) volcanic quakes were detected by the seismic network for the past 24 hours.
  2. Gas measurements conducted at Taal Main Crater Lake yielded CO2 emission flux of 1,875 tonnes per day (t/d) in February 2011 and 4,670 t/d during the last week of March 2011. The remarkable increase in C02concentration indicates its release from the magma at depth. 
  3. Result of the ground deformation survey (precise leveling) conducted around the Volcano Island this week showed that volcano edifice is still inflated as compared with February 2011 survey.
  4. Steaming activities at the northern and northeast sides of the Main Crater occasionally intensified. Sometimes, intensification of steaming activity is accompanied by audible hissing sounds. 
In view of the above observations at Taal Volcano and the interpretation that magma has been intruding towards the surface, as manifested by CO2 being released in Main Crater Lake and increase in seismic activity, Taal Volcano’s status is now raised to Alert Level 2.  With this alert status, the present activities could eventually lead to an eruption.  Hence, PHIVOLCS advises the public that the Main Crater, Daang Kastila Trail and Mt.  Tabaro (1965 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 gases can be lethal to human, animals and even cause damage to vegetation.   In addition, it is reminded that 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