Bulusan, Philippines : Two successive minor eruptive events .

Bulusan, Philippines : Two successive minor eruptive events  .

BULUSAN VOLCANO ADVISORY 22 February, 2016 18:00 P.M.

At 5:01 today, the Bulusan volcano (12 ° 46.2’N, 124 ° 03’E) has ejected a column of steam and gray ash that drifted into the West-East direction. Two successive minor eruptive events occurred on a crack in the west-northwest of the summit of Bulusan, which produced a grayish ash plume followed by a plume of steam and ash about 500 meters high. Based on seismic records, the signal of the eruption was composed of two (2) earthquake events, a rock fracturing event, followed a few seconds later by an earthquake explosion type , of a total duration of four minutes and twenty-one seconds. Before the ejection of ash, Bulusan seismic network detected a total of twelve (12) volcanic earthquakes.

Alert Level 1 remains in effect over Bulusan Volcano. The public is reminded not to venture inside the 4-kilometer radius Permanent Danger Zone (PDZ) because the area is at risk to sudden steam and ash explosions. Due to the prevailing wind direction, residents located in the northwest and southwest sectors of the volcano are advised to take precautions against ashfalls. Civil aviation authorities must also warn pilots to avoid flying close to the volcano’s summit as ejected ash and volcanic fragments from sudden explosions may pose hazards to aircrafts. Furthermore, residents near valleys and river/stream channels should be watchful against sediment-laden stream flows and lahars because ash and other loose volcanic materials may be remobilized during heavy and prolonged rainfall. DOST-PHIVOLCS is closely monitoring Bulusan Volcano’s activity and any new significant development will be immediately relayed to all concerned.

BULUSAN VOLCANO BULLETIN 23 February 2016 8:00 A.M.

Bulusan Volcano’s seismic monitoring network recorded six (6) volcanic earthquakes during the past 24 hours that included a minor eruption at 5:01 P.M. yesterday. The eruption generated a short steam and ash column approximately 500 meters high from the west-northwest fissure vent of the volcano summit and was recorded as a high frequency earthquake followed by a low frequency earthquake lasting four minutes twenty-one seconds. The explosions were accompanied by a rumbling sound reportedly heard at Puting Sapa, Juban and Bolos, Irosin. Prior to the eruption, the Bulusan seismic network detected no volcanic earthquake, although increased seismicity was recorded on 20-21 February. Traces of volcanic ash were reported in Brgys. Puting Sapa, Sagkayon, and Caladgao in Juban and Brgy. Bolos in Irosin. Presently, moderate emission of 50 meter-high white steam plumes towards southwest occurs at the west-northwest vent while weak emission of steam from southwest summit vent can be observed. Precise leveling survey results from December 2-7, 2015 indicated slight inflationary changes of the volcano’s edifice relative to September 2015, consistent with ground deformation measurements from continuous GPS data since August 2015.

February 23 , 2016. Bulusan, Philippines :

Source : Phivolcs.

Photo : Thoni Huang ,

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