Updated

A minor earthquake has scientists continuing to closely monitor a New Zealand volcano that erupted for the first time in more than a century this week.

The steam-triggered eruption Monday of Mount Tongariro on New Zealand's North Island sent boulders flying, covered surrounding areas in ash and disrupted domestic flights.

Scientists flew over the area for the first time Wednesday. Volcanologist Steve Sherburn says it appears the eruption blew three new holes in the north side of the mountain, including one about the size of a house. He says it's not yet clear what to expect next from the volcano, which continues to vent steam.

He says the overnight quake, which had a magnitude of less than 3, continues a recent series of temblors in the area.