The earthquake generated a regional tsunami with wave heights of up to 6 metres reported in American Samoa. Estimates of earthquake magnitude and depth have been released by the United States Geological Survey (magnitude 8.0, depth 18 km) and the Pacific Tsunami Warning Center (magnitude 8.3, fixed depth of 33km).
New Zealand Tsunami Gauge Network snapshot as at 09:55:06 NZDT 01/10/2009. Note the Raoul Island plots in particular.
Based on the location, magnitude and depth estimates, the Ministry of Civil Defence and Emergency Management (MCDEM) issued a Tsunami Warning - Threat to New Zealand bulletin at 7:15 am. GNS Science, via the Tsunami Experts Panel, is providing ongoing technical advice to MCDEM. The public is being advised to stay away from the sea and beaches in Northland, Coromandel, Bay of Plenty, along the East Coast of the North Island north of Gisborne, and on the Chatham Islands with run-ups predicted to reach up to one metre at the coast. Strong currents in the sea are likely in these areas. Data from the GNS Science tsunami gauges on Raoul Island show that the initial arrivals are not the largest, and it is likely that this will be the case in the other areas.