Some Wellington residents were woken by the first of two earthquakes which occurred in the Wellington region this morning.
A light magnitude 4.1 earthquake, 30 km deep and centred 10 km West of Porirua occurred at 5:24 a.m. and Geonet reports that it was felt in Porirua, Tawa and elsewhere in the Wellington region. The tremor rattled doors and windows in Tawa, but no damage reports have yet been made.
A smaller event 125 minutes later at 7:31 a.m. was notable for the associated sonic boom which was heard at the southern end of the Tawa Valley. This earthquake has not been detailed on the Geonet website, but clearly shows on the seismometers at Karori and Mangatainoka. It was probably centred somewhere in the Tawa-Porirua basin area, and was probably shallow which allowed some of the released energy to be transferred into the air and heard as a “boom” sound.
Last month, on December 13th, a magnitude 4.5 earthquake, 30 km deep with an epicentre 10 km north-east of Porirua was felt throughout the Wellington region, and caused minor damage.