Gas hydrates: a warning from the past
The pockmark area where more than 7000 pockmarks that have been mapped. Indicated are the Troll A platform. Inset map: offshore Norway
A group of Norwegian researchers led by CEED`s Adriano Mazzini have studied the numerous randomly distributed elliptical pits (pockmarks) in the seabed above the Troll gas field in the northern North Sea off western Norway. Their work show that the pockmarks were formed during the initial Holocene, at approximately 11,700 years ago, and this implies that the pockmarks formed as a consequence of the rapid climatic changes following the Younger Dryas. The Younger Dryas is a climatic event from c. 12,900 to c. 11,700 calendar years ago, with a sharp decline in temperature over most of the Northern Hemisphere.
Gas hydrates are thought to be present beneath shallow seas today, wherever sea-floor sediments have a significant organic carbon content. Mazzini et al.’s analysis of the Troll pockmark field clearly has profound implications for the possible behaviour of gas hydrates at a time of global climatic warming, with a their destabilisation adding the green house gas methane to the atmosphere.
The report from Earth Pages - Research News from the Earth Sciences can be found here,
The Scientific basis for the report is the article mwhrere the Norwegian geoscientists have studied part of the field in considerable detail, analysing carbonate-rich blocks and foraminifera in the pits : A climatic trigger for the giant Troll pockmark Field in the Northern North Sea, Mazzini et al., 2017. Earth and Plantary Science Letters, 464, 24-34.