Seven volcanic earthquakes in Bulusan Volcano in Sorsogon were recorded in the past 24 hours, the Philippine Institute of Volcanology and Seismology (Phivolcs) said in its bulletin on Tuesday, June 7.

In its 8 a.m. bulletin, Phivolcs had also detected a 150-meter-high “voluminous” emission from the volcano.

Following its phreatic eruption, Bulusan Volcano’s alert status was raised to Level 1 on Sunday, June 5, which means there was a “slight increase” in volcanic earthquake and steam or gas activity.

Bulusan Volcano’s phreatic eruption in 2017 was similar to the eruption that transpired on Sunday, said Science and Technology Undersecretary and Phivolcs OIC Renato Solidum Jr.

He added that no magmatic eruption had been recorded over Bulusan Volcano since early 1900s.

Under Alert Level 1, Phivolcs also noted that there is a continuing threat of “sporadic explosions from existing or new vents.”

Likewise, there is a notable increase in the temperature of hot springs surrounding the volcano and slight inflation or swelling of the volcano’s edifice.

Phivolcs reminded the public that entry into the four-kilometer permanent danger zone is strictly prohibited because of possible sudden steam-driven or phreatic eruptions.

Meanwhile, the public is advised to remain vigilant when entering the two-kilometer extended danger zone, which is on the southeast sector of Bulusan Volcano.

Furthermore, people living within valleys and along river/stream channels especially on the southeast, southwest and northwest sector of the edifice were advised to be vigilant against sediment-laden stream flows and lahars in the event of heavy and prolonged rainfall should another phreatic eruption occurs.