|TAAL VOLCANO ADVISORY 23 November 2012 8:30 A.M.|
|Friday, 23 November 2012 00:45|
This is notice of a remarkable increase in the seismic activity of Taal Volcano. Taal Volcano’s (14.0000°N, 120.9833°E) seismic network recorded a total of sixty (60) volcanic earthquakes during the past 24-hour observation period. Two of these events were felt by residents of Calauit and Pira-piraso located at the northeast and southeast sectors of the volcano island, respectively. The first event occurred at 7:12 P.M. and was felt at Intensity II. The second event occurred at 7:23 P.M. and was felt at Intensity III accompanied by a rumbling sound. These events, together with most of the recorded volcanic earthquakes, were located in the north-eastern sector of Volcano Island.
All other monitoring parameters remain less remarkable. Field measurements conducted on 20 November 2012 at the eastern sector of the Main Crater Lake yielded slight increase in water temperature of 34.2°C from 33.4°C, a decrease in water level of 1.30 meters from 1.34 meters and decrease in acidity of pH 2.98 from pH 2.71. Ground deformation survey (precise levelling) in the Volcano Island on 02-11 October indicated slight deflation compared with July 2012. GPS data for the period of February 2011 to October 2012 show no substantial changes in ground deformation recently, although the edifice is still slightly inflated compared to February 2011 baseline data. Carbon dioxide (CO2) emission at the Main Crater Lake increased to 627 tonnes per day on 07 July 2012 compared to 482 tonnes per day last 18 October 2011.
Alert Level 1 is reinforced over Taal Volcano. This means that hazardous eruption is not imminent. The public, however, is reminded that the Main Crater should be strictly off-limits because sudden gas/steam explosions may occur and high concentrations of toxic gases may accumulate. The northern portion of the Main Crater rim, in the vicinity of Daang Kastila Trail, may also become hazardous when gas/steam emission along existing fissures suddenly increases. Furthermore, the public is also reminded that the entire Volcano Island is a Permanent Danger Zone (PDZ), and permanent settlement in the island is strongly not recommended.