Tuesday, June 13, 2006

Bulusan Volcano Update

07 June 2006, 11:30 PM

After the ash explosion that occurred at 4:17 PM of 31 May 2006, Bulusan Volcano (12o46.2’N, 124o03’E) produced another episode of ash emission which began on 8:17 PM and lasted until 8:30 PM today. The explosion generated an ash and steam cloud that rose to about 2 kilometers above the volcano’s summit as observed from San Benon-Monbon area. The initial ash explosion was recorded by the monitoring stations around the volcano. Seismic records indicated that no volcanic earthquake preceded the explosion event. No damage was reported from the volcanic explosion and only light traces of ash affected the north, west and southwest sectors of the volcano. Initial investigation showed that areas which experienced the light ashfalls were the municipalities of Casiguran, Sankayon in Juban, Gulang-gulang and Bolos in Irosin, Sorsogon.

This most recent explosion is the 5th in a series of ash and steam-driven explosions this year after reactivation of Bulusan Volcano on March 21. These explosions appear to be increasing in frequency and it is the general observation that this volcanic activity reflects intrusion and ascent of magma. In support of this assertion is the possible presence of glass particles in ash retrieved from the May 25 ash emission.

With a general increasing trend of volcanic activity and the likely involvement of magma as the cause of the volcano’s recent explosions, PHIVOLCS is now raising the alert status of Bulusan Volcano from Alert Level 1 to Alert Level 2. This alert condition signifies a continuing state of unrest which could lead to more frequent ash explosions or to hazardous magmatic eruption. With Alert Level 2, PHIVOLCS strongly recommends no entry within the four (4) kilometer Permanent Danger Zone (PDZ) to minimize risks associated with volcanic flows and effects of explosions. River channels draining the upper slopes should also be avoided especially during heavy rains because life-threatening lahars may occur in these areas.

[Source]

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