Gas Hydrates Mapped Off Europe

Credit: University of Southampton
Credit: University of Southampton

Published Jan 15, 2020 7:45 PM by The Maritime Executive

A study led by the University of Southampton has mapped several sites in Europe containing gas hydrate including areas off the west coast of Greenland, around Svalbard, off central Norway and west of Ireland.

Vast amounts of natural gas are stored in an ice-like form beneath the seabed, under the deep seafloor, close to the edge of landmasses. This gas hydrate, sometimes known as “ice that burns,” has the potential to play a role as a substitute for coal.

The hydrate can only exist in stable form under the low-temperature, high-pressure conditions of the seabed. It's molecular structure is a cage-like lattice of ice inside which are trapped molecules of methane, the chief constituent of natural gas. When brought to the earth's surface, one cubic meter of gas hydrate releases 164 cubic meters of natural gas. 

Hydrate deposits may be several hundred meters thick, and they have been found around the world. Estimates of worldwide reserves range from 280 trillion cubic meters (10,000 trillion cubic feet) up to 2,800 trillion cubic meters (100,000 trillion cubic feet), according to the U.S. Energy Information Administration. Japan, China, the U.S. and India have research underway on the fuel.

This new inventory of gas hydrate deposits was undertaken as part of MIGRATE (Marine Gas Hydrates: An Indigenous Resource of Natural Gas for Europe), a project funded by the European Commission and led by the GEOMAR Helmholtz Centre for Ocean Research, Kiel.

Professor Tim Minshull of the University of Southampton, who led a 31 strong-team from 14 countries, said: “We found that gas hydrate is particularly widespread around Svalbard, off Norway and in the Black Sea, but the hydrate systems have only been well investigated in a few areas, so there could be much still to discover.

“Exploiting gas hydrate deposits safely and efficiently presents challenges, for example, converting the hydrate to gas without using up too much energy. But several large feasibility projects are exploring these and other factors.”

The study authors note that the inventory has environmental value. If oceans warm due to climate change, hydrate may naturally melt, releasing methane which could change the chemical balance of the oceans. Mapping where this might happen will help scientists monitor progress.