Source: Earth Sciences New Zealand
New methane seeps are being discovered at an astonishing rate in Antarctic waters.
Methane is a greenhouse gas, so scientists are investigating how these sources of methane may be connected to our warming climate.
Earth Sciences New Zealand marine scientist Dr Sarah Seabrook says these seeps are recently formed, indicating a fundamental shift in regional methane release around the continent.
“Methane seeps are areas of the seafloor where methane and other chemicals escape from reservoirs underneath the seabed and dissolve in the water, often having streams of bubbles that extend all the way up to the surface.
“The first was discovered by chance in 2012 and since then they’ve been cropping up at a remarkable rate. A similar phenomenon has also been observed in the Arctic,” said Dr Seabrook.
“Every time we discover or hear of a new one, we feel immediate excitement, but that excitement is quickly replaced with anxiety and concern about what it all means. If they follow the behaviour of other global seep systems, there is the potential for rapid transfer of methane to the atmosphere from a source that is not currently factored into future climate change scenarios,” said Dr Seabrook.
The Earth Sciences NZ team have been using remotely operated vehicles and divers under the ice to search for new seeps, sampling sites ranging from approximately five to 240 meters deep.
“Last year, we went to Cape Evans to look at one small area where gas bubbles had been discovered and were hoping to find that one site still bubbling. Instead, we found dozens more. If these seeps keep emerging at the areas we are working in, it really begs the question of what the shallow coastal environment of Antarctica may look like five or 10 years from now. This system is rapidly changing before our eyes from one year to the next.”
Dr Seabrook and her team will be returning this season to investigate more seep sites. However, some areas from last season such as Cape Evans are inaccessible because of disappearing sea ice.
This work is funded by a Royal Society of New Zealand Marsden Grant and the Antarctic Science Platform.
