Your Journey Begins!

Web Search

Undersea tsunami threat

SEAFLOOR SLIP: The steep 300-metre-deep walls of Nicholson Canyon show signs of a massive tsunami-causing rockslide.

Breaking Earth News

New Zealand
Evidence of a massive undersea landslide has been found less than 15 kilometres from Wellington airport, raising fears another slip could trigger a devastating tsunami. Niwa scientists found signs of a huge submarine rockslide in the Nicholson Canyon, which lies in Cook Strait, south of Wellington Heads. Using underwater scanning equipment, they found a giant scar on one of the canyon's 300-metre- high walls. The amount of rock that had collapsed into the canyon was huge - a billion cubic metres. That's four times the size of Wellington's Mt Victoria. There was no way of telling how old the landslide was, as the debris had now washed away. Evidence of smaller rockslides was also found in the nearby Cook Strait canyon. An underwater landslide could cause a tsunami, depending how fast the slip moves and the ocean depth. "Obviously Wellington airport is only a few metres above sea level, so it's vulnerable, but I couldn't say what the damage would be." A tsunami triggered by the 1855 Wairarapa earthquake might have been helped along by an underwater landslide. That tsunami sent waves between Lyall Bay and Evans Bay. Submarine landslides tend to cause more localised tsunamis than those sparked by earthquakes. A tsunami from the Nicholson Canyon would hit within Wellington "within minutes". "It's potentially one of the most devastating tsunami events you can have."

Multi-Media Information

Multi-Media Information

Video Newsflash

Website Disclaimer