Big shake's 'unlikely' as quake swarm rattles on

A swarm of about two dozen earthquakes which have been rocking parts of the Western Bay and Eastern Waikato continued today with another shake at 1.43am.
The latest tremor was within 5km of Te Aroha, measured 2.9 on the Richter scale and was 6km deep. It shook the town.
Scientists say the shake is the latest in a series of up to 20 earthquakes centred near Te Aroha which have also rattled homes in the Katikati and Waihi area since last Friday.
In an unrelated tremor, an earthquake measuring 3.8 on the Richter scale also shook Wanganui at 12.37am this morning.
But vulcanologists believe the Bay/Waikato quakes are not the forerunners of a larger one.
Brad Scott, vulcanologist with the Institute of Geological and Nuclear Science at Wairakei, said frequent earthquakes, like those felt over the past few days, were not uncommon in volcanic areas such as Te Aroha and are unlikely to mean the now extinct volcano is about to erupt or that there will be bigger earthquakes.
"Swarms of earthquakes are common in the volcanic region. In 1972 a magnitude 5.2 event occurred in this area damaging some homes," he said.
"Most swarms last only hours or a few days. From historical trends we would expect the swarm to gradually settle down and not trigger a larger event but we cannot rule out that possibility."
The recent swarm of quakes started at 2:48 pm on Friday with a magnitude 3.0 event at 15 km depth and Mr Scott said while the institute's equipment recorded the quake, no reports were received from people who felt it.
That tremor was followed at 6:41 pm by a 3.1 event, and then a 3.3 event at 1:22 am on Saturday morning.
During the next 10 hours instruments recorded at least 14 further tremors. Only four small quakes were recorded during the next four hours, before the largest earthquake so far, a magnitude 3.7 occurred at 4:46 pm on Saturday.
"This event was felt in Te Aroha, Katikati and Waihi, and has been followed by several mainly small aftershocks, with the largest being one of 3.5 at 6:29 pm. These latter events have been at 4 to 6 km depth," he said.
Mr Scott and the team at the Institute provide regular updates on earthquakes on the website -www.geonet.org.nz- through the New Zealand GeoNet Project.
It provides real-time monitoring and data collection for civil defence response and research into earthquake, volcano, landslide and tsunami hazards.
The GeoNet project is a collaboration between the Earthquake Commission, the Institute of Geological & Nuclear Sciences and the Foundation for Research, Science & Technology.
The public can report their experiences of earthquakes on the site where regularly updated photos from cameras on Taranaki (Mt Egmont) Ruapehu, Ngauruhoe and White Island can also be viewed.