Cook Strait Canyon

New Photos Show Deep Canyons

Stretching Through Cook Strait

Kapiti Independent News
18th September 2009
Images Kindly supplied by Niwa and are copyrighted.

Cook Strait Bathy - CopyNew scientific pictures have revealed massive undersea canyons stretching though Cook Strait.

NIWA (the National Institute of Water and Atmospheric Research) says its latest research will help warn Wellington of potential tsunamis, which would be set off by landslides in the canyons.

It says its new high definition underwater imagery reveals just about everything on the sea floors.

It says the days when we all wondered or guessed what the sea floor area of Cook Strait and other areas might look like have now gone forever.

The stunning pictures in high definition of the Cook Strait show vast and complex features.

The Strait is renowned for being one of the world’s stormiest stretches of water — with strong winds, strong tides and seas that scour and move sediment on the sea floor.

Steep canyons, some more than 2000 metres deep, extend almost to Wellington’s harbour entrance. The pictures reveal huge, almost vertical flanks which are prone to landslides.

The tectonic faults that cross the strait cause earthquake and tsunami hazards. Occasionally, they produce large earthquakes — the last in 1855, according to Niwa.

With such a complex area, there are major challenges for engineers dealing with power cables and telecommunications. Any attempts to harness the tides for energy will be problematic.

Niwa’s new imagery — better known as “The Digital Elevation Model” — was developed by water depth data, including high resolution multibeam soundings, and was acquired from the deepwater research ship “Tangaroa” on five voyages between 2001 and 2005.

Cook Strait seabed - CopyWith this data, scientists will be able to work out whether predicted landslides could trigger a tsunami and threaten Wellington.

The data will also be used to study Wellington’s new marine reserve and will be shared with other organizations.