BULUSAN VOLCANO BULLETIN 11 January 2017 8:00 A.M. PDF Print

Bulusan Volcano’s seismic monitoring network recorded one (1) volcanic earthquake during the past 24 hours. Steaming activity could not be observed due to thick clouds covering the summit. Sulfur dioxide (SO2) emission was measured at an average of 37 tonnes/day on January 5, 2017. Precise leveling data indicated inflationary changes of the edifice relative to August 2016, based on October 17-23, 2016 survey. However, continuous GPS measurements indicated slight deflationary trend since November 2016, as of December 31, 2016.

In addition, last 09 January 2017, a series of lahar events occured in the channels traversing Brgys. Mapaso and Patag, Irosin. These events were detected by a seismic monitoring station in southern Bulusan between 6PM to 11PM. Another series of small lahar events continued until 2AM of the following day. In result, boulder-strewn lahar deposits clogged these channels as observed from an ocular survey.

Alert Level 1 (abnormal) remains in effect over Bulusan Volcano. This indicates that hydrothermal processes are underway beneath the volcano that may lead to steam-driven or phreatic eruptions. Local government units and the public are reminded that entry into the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited and that vigilance in the Extended Danger Zone (EDZ) must be exercised due to the increased possibilities of sudden and hazardous phreatic eruptions. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden phreatic eruption can be hazardous to aircraft. Furthermore, people living within valleys and along river/stream channels especially on the southeast, southwest and northwest sector of the edifice should be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall. DOST-PHIVOLCS is closely monitoring Bulusan Volcano’s condition and any new development will be communicated to all concerned stakeholders.