Tsunami threaten New Zealand
New Zealand is in a tectonically active part of the roaring forties and is vulnerable to a wide range of natural
hazards. Yet, the threats of a tsunami in New Zealand are underrated, according to the latest report from the Natural
Over 40 years have passed since the last major tsunami hit New Zealand, and there is little awareness of the damage a
tsunami could cause or how to respond to warnings, reports Natural Hazards Update, the Centre’s new newsletter, which
was published today.
On 23 May 1960 a magnitude 8.5 earthquake in southern Chile generated a tsunami that swept across the Pacific, causing a
major loss of life in Chile, Hawaii, and Japan. Although no deaths or injuries were recorded in New Zealand, there was
widespread damage to coastal facilities and small boats. Thousands of people were evacuated, making it the largest ever
evacuation in New Zealand history.
At the time there were widespread reports of people ignoring the warnings and going to the coast to get a better view of
the approaching tsunami. This could have been disastrous.
“After the event there was much discussion in the newspapers of the need to improve the warnings and public awareness of
the threat. These issues are still relevant today,” the report said.
Tsunami are just one of the natural hazards we face. Others being identified by the Natural Hazards Centre include
storms, floods, droughts, landslides, earthquakes, volcanic eruptions, and coastal erosion.
The Institute of Geological and Nuclear Sciences (GNS) and the National Institute of Water & Atmospheric Research (NIWA) established the Natural Hazards Centre to inform New Zealanders of the extent of these
“We want to strengthen the links between scientists, policy makers, planners, and emergency managers by providing a
focal point for science-based information on natural hazards,” the report said.
The scientists’ knowledge is supported by a nationwide monitoring network recording sea level, seismic and volcanic
activity, climate, and hydrology.
Large tsunami – like the ones that struck Papua New Guinea recently – may be infrequent, but they are usually
catastrophic, which means the risk of damage and loss of life is substantial for low-lying coastal areas. Smaller
tsunami of about 1 m are more frequent, occurring somewhere in New Zealand about once every 10 years, but if they
coincide with a high spring tide or a local storm, they can cause significant damage.
Recent marine geological research by GNS and NIWA on New Zealand’s east coast continental shelf and north of the Bay of
Plenty has produced some spectacular images of the seafloor and provided the means to identify potential local tsunami
threats from submarine landslides, fault ruptures, and volcanoes.