Tsunami? Not today thankfully

So I was enjoying a bit of a sleep-in on Friday before heading out to the final day of the Joint Centre for Disaster Research's Emeregency management Summer Institute when my phone wakes me up to tell me that there's a National Advisory - Tsunami: Potential threat to NZ.

I woke up in a hurry, let me tell you!

An earthquake measuring 7.7 on the Richter Scale had occurred at 7.18am NZDST, at a depth of 48km, in the region of the Tongan islands. 23.0 South, 174.8 West.

An earthquake of this size automatically generates a tsunami warning from the Pacifc Tsunami Warning Centre, because such earthquakes often generate destructive tsunamis that can strike coastlines near the epicenter within minutes or hours, so any warning is better than none. The centre then monitors sea level gauges nearest the region and reports if any tsunami activity was observed.

GNS Science convened the tsunami expert panel and all the available NZ and international data about the earthquake and sea levels was being closely monitored and analysed.

The only tsunami wave activity reported was from Niue at 8.11am NZDST, where they had waves 4cm higher than usual every 6 minutes, so the warning was cancelled and we could all relax and get on with our day.

Certainly caused a bit of a flurry of activity - there is nothing more frustrating than waiting for your computer to start up in the morning when there is something time-critical that you need to look at.