Weather, Earthquakes, Water and Ground Control  
engineering solutions for monitoring the environment
NZ Tsunamigenic Earthquake
16 July 2009

NZ Earthquake


The images to the left are waveforms of the tsunamigenic earthquake that occurred in New Zealand on Wednesday evening, as recorded by the Seismology Research Centre in eastern Australia. Data is collected from Australian made Kelunji Seismic Recorders and displayed using our eqWave Analysis Software.

Image 1 shows the earthquake being recorded at our seismic stations, with the seismic waves arriving earlier at closer stations. The earthquake origin time was 0922 UTC (7:22pm AEST) so the seismic waves took about 3 minutes to reach Australia. The tsunami waves generated by this event took over two hours to reach Australian shores.

Image 2 shows one of these waveforms in more detail. Note that the time scale shows minutes in UTC time. Our broadband seismic stations continued to show the earth shaking from this event for over three hours.

Image 3 shows the automatic earthquake bulletin that was generated by our eqWatch alerting system, which was issued less than 4 minutes after the earthquake waves hit the ES&S seismic monitoring network. Our seismic network is designed to monitor earthquakes within the network, so the automatic location of this NZ event is a reasonable effort given that the stations are over 1500km away from the epicentre.