"In January this year we saw more of that raised activity although the island has been pretty quiet since then."
While admitting to not being a scientist, Mr O'Sullivan said he believed the bouts of raised activity to be like a pressure cooker.
"The island lets of a bit of steam and then returns to its usual quiet self for a bit longer. I remember as a youngster White Island was always letting off steam."
He said it would be business as usual for White Island Tours tomorrow unless GeoNet instructed otherwise.
Clinton Naude, Regional Manager appointed for Bay Civil Defence, said activity on the island was being monitored by staff.
"What we normally do in these situations is get in touch with the tour operators then keep a close eye on what the island is trying to do," Mr Naude said.
"At this stage there is nothing causing us too much concern."