The Icy Fire Beneath Norway’s Seabed
Trapped by deep ocean pressure and cold temperatures along continental shelves, methane hydrates could be an energy windfall or a looming disaster. Norway is spending millions to discover whether this ice-like form of natural gas will prove boon or bane.
The landers lashed to the aft deck of the R/V Helmer Hanssen held firm as waves crashed into the ship. The two golf-cart-sized crafts, stocked with scientific instruments, appeared ready for planetary exploration, but in a few hours, they would be winched down to the seafloor off the coast of Svalbard, about 1,300 kilometers (800 miles) from the North Pole. If all went well, the landers would stay there for a year, powered by half a tonne of lithium batteries, monitoring the methane bubbles seeping from the seabed.
As a greenhouse gas, methane is 25 times more potent than carbon dioxide (CO2). Scientists have found that oceans absorb much of the methane bubbling up from seafloor seeps, but they don’t quite know how much. And their real worry is the 10,000 gigatonnes of methane trapped worldwide as a solid beneath the seafloor in the form of methane hydrate. With ocean temperatures on the rise, methane hydrates pose a threat far greater than the seeps. Although hydrates also exist on land beneath permafrost, 99 percent of known reserves are buried beneath the seafloor. Some of Norway’s largest reservoirs lie right along the continental shelf, where a slight rise in temperature could thaw the methane hydrates — and unleash vast quantities of the gas, slowly over time — or possibly quite quickly.
“Methane hydrates serve as a kind of cement of the sediments. Our fear is that if the cement gets dissolved, sediment might slide down the [continental shelf] slope,” Peter Linke told me in the instrument room of the Hanssen. Linke, a marine biologist —> Read More