February 2002 - Nr. 2
Fire and Ice
German Geologists Study Undersea Fuel Source
TWIG - German scientists are exploring the power of a potential new energy source: flammable ice buried beneath the sea floor. About 12 trillion tons of the undersea substance called methane hydrate can be found at the bottom of the ocean. The material is snow-white and ice-cold, but according to Erwin Suess of the Research Center for Marine Geosciences (GEOMAR) in Kiel, it harbours more burnable carbon than all the world’s fossil fuels combined. In 1999, Seuss and his research team recovered more than 100 pounds of the carbon compound from a vast deposit off the coast of Oregon. "It was almost like transporting an ice cube through a desert," says Suess, who won the 2001 Philip Morris Research Prize for his work on methane hydrate.
The substance is formed from the decayed remains of plankton, fish and algae in extreme cold and under high pressure, and begins to dissolve when temperatures rise or pressure subsides even slightly. Seuss and other scientists on board the German research ship Sonne used a video-guided grab sampler to break off and lift sizzling blocks of it to the surface. Chunks of the volatile material have been preserved in liquid nitrogen at –200° C and are being studied by chemists, biologists and geophysicists at GEOMAR.
Natural gases such as methane burn cleaner than oil or coal, says Gerhard Bohrmann, a member of Seuss’s research team. But transporting the substance remains a problem. Companies eager to harness its energy might do better to melt it on the spot and store the methane in gas form instead. India and Japan are already planning such projects, Bohrmann says.
Yet methane hydrate poses dangers, too. Methane is a powerful "greenhouse gas" – about 30 times stronger than carbon dioxide in its capacity to cause global warming. As the seas are warmed by the greenhouse effect, methane hydrate deposits could begin to melt on their own, thereby accelerating global warming. If the chain reaction continues and the deposits supporting the continental shelf collapse, the result could be tidal waves and massive flooding along the world’s coastlines. Some scientists hold methane hydrate responsible for other catastrophes as well. When pieces of the compound decompose, the methane gas they release rises to the surface in a storm of bubbles. The action can reduce the buoyancy of the water and even cause ships to sink. That may be the reason vessels sometimes "disappear" in areas like the Bermuda Triangle, some experts believe.
As destructive as methane hydrate can be, it may offer a solution to global warming as well. If scientists learn to make a similar gas hydrate from excess carbon dioxide, the ubiquitous greenhouse gas could be pumped into the ocean and disposed of safely on the sea floor. But for now the goal is to make sure current methane hydrate deposits stay as stable as possible. With support from the German Federal Ministry of Education and Research and the U.S. National Science Foundation, Seuss and his team at GEOMAR are about to join scientists from Oregon State University for a six-month study off the coast of Oregon, monitoring a "burnable ice" field some 1,500 feet under the sea.
