Ongoing earthquake sequence continues
The current earthquake sequence beneath the Bay of Plenty in a location 100 km to the east of Whitianga, has now reached over 230 quakes in the last 7 days and continues tonight. At this stage the main shock in the sequence was a magnitude 5.2 at 3:47 am on Saturday 29th August. There has also been five quakes above M 4.0 all which have been felt across parts of the Coromandel peninsula, Gulf Islands and Auckland in the last 2 days.
The region where the earthquake sequence is currently underway, is further north than the majority of past events which has meant areas around the Hauraki Gulf are feeling the seismic activity. Until the current event subsides, it won’t be known if the M 5.2 quake is the main shock but hopefully it is.
GeoNet provided an update on the weekend which can be referenced on the following link. https://www.geonet.org.nz/news/7uTSDwuCTY1OELFjJl8dDH
After reviewing historical events, there is a comparable earthquake sequence location which dates back to late December 1984 when a series of moderate earthquakes were followed by a stronger earthquake. Between 27th to 31st December 1984, there were 17 fore-shocks between M 5.0 to M 5.7 before a main shock of M 6.7 occurred at 10:36 am on 31st December, 1984.
Images courtesy of GeoNet, with descriptions included by HGW.