Lake Rotoaira Earthquake Swarm

A series of light earthquakes felt at Turangi (south of Lake Taupo volcano) overnight, has drawn attention to an earthquake swarm occurring on the northern shore of nearby Lake Rotoaira.

Monday 1st June 2009

Residents of the ski resort of Turangi felt a short series of earthquakes around midnight and early this morning. The magnitude 3 quakes were the larger members of an earthquake swarm located on the northern shore of Lake Rotoaira, 10 km south-west of the town.

The burst of activity appears to have started just after 4 p.m. on Sunday afternoon when the first of the shallow quakes struck on-shore between the central North Island lakes Rotoaira and Rotopounamu. Since then, some 34 events have been recorded in the area by GeoNet.

Preliminary analysis of the events listed in GeoNet’s database shows that there have been 7 quakes of magnitude 3, 22 of magnitude 2 and 5 of magnitude 1. Most of the earthquakes are occurring at depths of less than 10 km, the deepest being at 12.8 km.

The larger members of the swarm have been a magnitude 3.1 quake at 10:33 p.m. Sunday night, followed by a magnitude 3.3 at 11:02 p.m., a magnitude 3.2 at 11:08 p.m., a magnitude 3.3 at 11:54 p.m. and the largest of the series, a magnitude 3.8 earthquake at 2:31 this morning. This was followed by a magnitude 3.2 event at 2:37 and a magnitude 3.5 quake at 3:17 a.m.

Seismic drums indicate that the activity ceased after a magnitude 2.8 earthquake struck at 5:17 this morning.

[Compiled from data provided by the GeoNet project and its sponsors EQC, GNS Science and FRST.]

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