Munich

An international team is this month scouring the floor of the Black Sea in an effort to gather more information on energy-rich methane hydrate crystals. Resembling ordinary ice, these structures are stuffed with natural gas and have been cited as a potentially massive source of energy.

Hot property: the team aboard the Meteor hopes to capitalize on the huge energy potential of methane hydrate (inset). Credit: G. BOHRMANN/GEOMAR

Methane hydrate can form only at reasonably high pressures and low temperatures, and so is found mainly in the Arctic permafrost and on the sea bed along the edge of continental shelves. The volume of gas it contains gives it great potential as a fossil fuel — the US Department of Energy, for example, estimates that successfully tapping just 1% of existing methane hydrate could yield more energy than the world's entire reserves of natural gas.

Margasch, as the Black Sea expedition is known, is studying the structure and architecture of methane hydrate in sediments just below the sea bed. It plans to map their distribution and hopes to estimate the total quantity of hydrate available. It is also using video-guided tools to retrieve samples of the crystals.

“Its near-surface deposits make the Black Sea a preferable destination for studying hydrates,” says expedition leader Gerhard Bohrmann, a geologist at the GEOMAR research centre in Kiel.

The team, which includes geophysicists, geochemists, biologists, oceanographers and meteorologists from Germany, France, Ukraine and Russia, left Istanbul on 2 January on the German research vessel Meteor.

The expedition has so far made good progress, Bohrmann reports. The scientists have already surveyed an active underwater mud volcano that releases methane, he says, and they hope that the data gathered will help them to test theories of how the hydrates form. They are also studying organisms that flourish at depths where the water contains no oxygen, surviving instead on methane.

Meteorologists, meanwhile, are interested in the influence that the hydrates might have on the composition of the atmosphere. Methane hydrate could be a significant source of atmospheric methane, an important greenhouse gas. Natural releases of the gas into the atmosphere could influence climate change, and German researchers aboard the ship are trying to establish how these releases occur.

The breakdown of the hydrates, triggered by changes in water pressure and temperature, is also thought to be responsible for seafloor landslides and large water waves (tsunamis). But most experts confess to being sceptical of the popular theory that they also sink ships in the foaming waters of the Bermuda Triangle.

→ http://www.gashydrate.de/projekte/omega/margasch