'Normal' to get lots of quakes

23:44, Dec 17 2013

The spate of small earthquakes near Seddon during the past few weeks were an expected part of the aftershocks from the July and August earthquakes, seismologists say.

Geological and Nuclear Science duty seismologist Caroline Little said yesterday that with aftershock sequences, people could expect to have not much noticeable for a while and then a little flurry of shakes.

Geonet sends out a tweet on social media tool Twitter, using the twitter handle @geonet, whenever there is an earthquake, saying where it was centred and how strong it was.

The twitter feed lists about 10 shakes over the past fortnight, most under magnitude 3.

Mrs Little said the twitter feed would definitely make people more aware of the shakes than they might otherwise.

"After I spent a lot of time in Christchurch, I felt a lot of imaginary earthquakes. Having the Twitter account to tell you about an earthquake means you can check whether it was a quake or just the wind or your partner rolling over in bed."


Seismologists would definitely expect more shakes for some time, she said. Predictions were that for the next year, an average of 20 4.0 to 4.9 strength earthquakes and about five earthquakes of about 5.0 to 5.9 magnitude could be expected.

That was around three times greater than what would normally be expected, she said.

"Everyone has pretty short memories. The last big big quake in Marlborough was in the 1800s. Unless your grandparents or their parents were around then, it's usually forgotten about."

Mrs Little said GNS collected the last portable monitoring stations at the end of November.

That data had just been extracted and was yet to be looked at. When analysed, it would refine where the aftershocks were.

"The aftershock sequence is now going on as we would expect."

The Marlborough Express