Natural methane (CH4) leaks at the surroundings
of Marambio (Seymour ) island
Spanish version here
Antarctic Scientists of the Instituto Antártico Argentino/Dirección Nacional del Antártico and Universidad del Salvador, Argentina, in a recently published scientific paper (1), report the significant presence of gaseous hydrocarbons, from methane (CH4) to penthane (C5H12), in sediments at the NW Weddell Sea (Antarctica), together with copious bubblings of methane. The latter phenomenon has been studied by the Argentine scientists at the surroundings of Marambio Island, since 1995, suggesting the existence of significant accumulations of methane in the marine substrate of this region of Antarctica. Methane is one of the major greenhouse gases responsible for global warming.
The release of methane from the frozen oceanic substrate in the vicinity of Marambio Island would be linked to climatic instability during Late Cenozoic, when vast areas of the Antarctic continental shelf were flooded by the sea during the marine transgression that occurred some 18,000 years ago, after the Last Glacial Maximum, when the climate began to improve and the ice began to melt, contributing with large amounts of water to the sea.
As the ice melted, the sea returned to occupy the regions it had left during the glaciation.
As the sea invasion was relatively rapid, the frozen ground at very low temperature, called "permafrost", was suddenly flooded and remained intact for some time, until the heat flow from the sea began to destabilize it, triggering the remarkable bubbling of methane, which is shown in the supplemental video:
Check video here: http://marambio.aq/video/gasmetano.html
This video shows the coastal environment at the Lopez de Bertodano Bay (NW of Marambio Island), during the low tide. Likewise, copious natural bubblings of methane are shown, at places where the water depth was approximately 1.5 m and its temperature was - 1.6 °C. The images were obtained during the 2012 austral summer, when the density of the leaks of methane was estimated as 1 escape every 20 m2 .
This process affects frozen accumulations of methane gas, originally formed within the subaerial permafrost during the Late Glacial Maximum, much as it does in the Arctic.
(1) R. A. del Valle (A) - E. Yermolin (A) - J. Chiarandini (B) - A. Sanchez Granel (C) - J. C. Lusky (B)
A) Instituto Antártico Argentino, 25 de Mayo 1143, San Martín, Provincia de Buenos Aires, Argentina
B) Dirección Nacional del Antártico, Balcarce 290, 2° Piso, C1064ABR Ciudad Autónoma de Buenos Aires, Argentina
C) Universidad del Salvador, Av. Callao y Córdoba, C1023AAB Ciudad Autónoma de Buenos Aires, Argentina
Original article: Methane at the NW of Weddell Sea, Antarctica. Hindawi Publishing Corporation, Journal of Geological Research, Volume 2017, Article ID 5952916, 8 pages.