We are heading to an area of exceptionally intense seafloor methane leakage, associated with sea surface oil slicks, first studied during a CAGE cruise last year. We plan to acquire new datasets to help us understand why so much methane is leaking from this area, and if this powerful greenhouse gas is reaching the sea surface and atmosphere.
Text: Monica Winsborrow, cruise leader for Hopendjupet CAGE21-4 cruise
August 4th, 2021.
We are grateful to be able to run cruises during these Covid times. But doing so requires us to be flexible and adaptable with our plans.
This is however my first cruise where we have arrived on board not yet knowing where we will go.
We arrived in Longyearbyen to board Helmer Hanssen with plans for two cruises prepared: (1) NE Greenland continental shelf, hunting for clues about how the Greenland Ice Sheet has behaved here in the past and how this may have influenced the release of carbon, stored beneath the seafloor and (2) an area of exceptionally intense gas seepage in the central Barents Sea, identified during a CAGE cruise last year.
University regulations due to Covid mean that we are restricted to how far we can sail from Tromsø, and this depends on weather and sea-ice conditions.
So, after looking at the sea-ice maps with the captain, it was decided that there was too much ice to allow us to go to Greenland. So, the decision was made. We set sail for the central Barents Sea.
Heading to the Barents Sea (Photo: Mauro Pau)
We are now on our way to the main study area accompanied by calm seas, sunshine and whales. Once we arrive our priorities will be identifying and mapping of seafloor methane release sites and then tracking the path of this powerful greenhouse gas from the subsurface sediments, through the water column and potentially to the atmosphere.
Onboard we are a team of scientists from CAGE and a colleague from the Norwegian Petroleum Directorate, ably supported by engineers Stormer and Truls.
Henry Patton looking for flares in the instrument room (Photo: Mauro Pau)