Volcanic alert status on Mt Ruapehu moved to 2 last week - the last level before an eruption.

The shift from 1 to 2 happened on Tuesday, GNS Science volcanologist Geoff Kilgour said.

While the mountain is being watched closely, an earthquake 15km northeast of Ohakune on Saturday wasn't a signal an eruption is imminent.

The earthquake of magnitude 3 happened at 2.32am. It was 14km deep. There was another smaller one nearby yesterday at 4.07pm.

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The first was on a well known fault, Mr Kilgour said, and there were usually at least two shakes there every week. On some nearby faults there could be 10 earthquakes a day.

"There doesn't seem to be any clear relationship between those earthquakes and what's happening at the volcano."

If magma is coming to the surface within the volcano you would expect a lot of earthquakes pretty much below the volcanic cone, he said.

He expected Ruapehu's volcanic alert situation to be re-evaluated today.