The RVO says there was a large blast towards the south on Friday, January 12.
“Big rocks were blasted out and there was a significant amount of material involved,” reports the Observatory.
“The rocks were glowing red. People on Ruprup Island, 15km to the north, could see red glow coming from the area of the summit, or from the hidden southern flank.
“Only one blast has been reported to date.”
The sleeping volcano, which erupted on January 5, is now emitting significant amounts of sulfur dioxide (SO2).