Huge seabed methane find off Canada's west coast
Date: 10-Sep-02
Country: CANADA
Author: Paul Willcocks
A remote controlled submarine discovered "glaciers" of frozen methane hydrates, which can be used to produce methane gas, on the sea floor about 130 km (85 miles) west of Vancouver Island, according to University of Victoria geophysicist Ross Chapman.
The technology needed to recover seabed methane is still in the development stage, but Chapman said researchers hoped the discovery of such a large deposit would spur more research.
"This is a very big discovery for us. It is important for (the industry) to know that there is hydrate right on the sea floor," Chapman said, noting that frozen hydrate is usually found several hundred metres (yards) beneath the seabed.
The researchers said seismic studies indicate the reserves in the undersea Barkley Canyon cover about 4 square kilometres (1.5 square miles) and could descend another 250 metres (820 feet) beneath the surface.
The methane, which freezes at higher temperatures under pressure, is trapped in frozen water molecules. Officials were alerted the deposit two years ago when a fishing trawler dragged up a one-tonne chunk of the ice.
The frightened crew hauled the hissing, melting mass on to their ship before shoveling it back into the sea. Chapman said the crew was lucky not to have been poisoned as the methane gas escaped from the melting ice.
The hydrates could also be an indicator of conventional oil and gas deposits beneath the sea floor. Their composition is similar to finds from the Gulf of Mexico associated with major oil and gas reserves, Chapman said.
When the submersible craft poked the seafloor, both oil and gas emerged and floated slowly to the surface.
The discovery comes as British Columbia and Ottawa are looking at lifting a 30-year ban on offshore drilling on the Pacific Coast. The province has launched a C$4 million ($2.6 million) review of the moratorium and hopes for a decision within 12 months.
Attention has been focused on conventional reserves north of Vancouver Island near the southern end of the Alaska panhandle, and any effort to allow drilling is expected to meet heavy opposition from environmentalists.
Chapman said scientists are also interested in the impact of such frozen methane deposits on global warming. Methane is a greenhouse gas and, as the ice melts. it could be released into the atmosphere.
The area off Vancouver Island is an active earthquake zone and Chapman said scientists also believe that earthquakes could break the ice free, releasing large amounts of methane into the atmosphere.
