Friday, December 01, 2006

Just because you cannot see it does not mean it is not there

An interesting phenomena that is not often seen or mentioned in climate studies is the underwater volcanic arcs of the pacific plate.With around 90% of the volcanic activity underwater there is some interesting discussion on this.What quantification of the energy budget to ocean currents and the SST and coupling may produce some interesting discussion.

Pictured View of the caldera of Macauley submarine volcano, from the northwest looking to the southeast. The caldera size varies from 6 to 10 kilometers across. Depths range from < 200 meters (~650 feet) at the rim to > 1000 meters (~3300 feet) at its deepest point.

"A normal hydrothermal vent might produce something like 500 megawatts, while this is producing 100,000 megawatts. It's like an atom bomb down there."

Recent studies have attempted to factor the heat from the world's known hydrothermal ridges into ocean circulation models. "Some studies estimate that for the Pacific, background thermal heating might increase ocean circulation by up to 50 percent," Murton said.

Regular hydrothermal fields stir the water for only a few hundred meters (about a thousand feet) above the ocean floor. "But these megaplumes can reach a column of 1,000 to 1,500 meters [3,280 to 4,920 feet], so it reaches right up into the midwater," he said.

But even the Indian Ocean megaplume may be small compared to larger underwater eruptions that have as yet gone undetected.

The Kermadec Arc is located in the southwestern Pacific, north of New Zealand. Over the past several years, international expeditions to the Kermadec Arc have found that over half of the submarine volcanoes surveyed are hydrothermally active. This year we will make dives to the seafloor to explore seafloor hotsprings on some of these active submarine volcanoes.


Post a Comment

<< Home

Web Counters