Hydrogen and oxygen isotope composition of precipitation and stream water on sub-Antarctic Marion Island. Issue 2 (22nd December 2017)

• Record Type: Journal Article
• Authors: Stowe, M-J.; Harris, Chris; Hedding, David; Eckardt, Frank; Nel, Werner
• Is Part Of: Antarctic science. Volume 30:Issue 2(2018)
• Page Start: 83
• Page End: 92
• Publication Date: 2017-12-22
• Subjects: amount effect, -- isotope hydrology, -- local meteoric water line, -- maritime island; Science -- Antarctica -- Periodicals; 509.989
• DOI: 10.1017/S0954102017000475
• Languages: English
• ISSNs: 0954-1020

Abstract

Abstract: We measured the hydrogen and oxygen isotope composition (δ 2 H and δ 18 O) of precipitation and stream water from the Soft Plume River at multiple spatiotemporal scales on sub-Antarctic Marion Island, Indian sector of the Southern Ocean. Monthly precipitation δ 2 H and δ 18 O values ranged from -43.7‰ to -14.7‰ and from -7.0‰ to -3.3‰ ( n =13), respectively. Stream water values ranged from -48.0‰ to -25.4‰ for δ 2 H and from -7.6‰ to -4.0‰ for δ 18 O ( n =92). The monthly precipitation data yielded a local meteoric water line with the equation δ 2 H=8.4δ 18 O+11.4. There was no clear seasonality in isotope composition present in precipitation and stream water. Along the stream, no significant difference was observed between sites. However, δ 2 H and δ 18 O values were lower and more variable at the highest site. This is probably the result of the 'amount effect', where more precipitation fell at a higher elevation compared with a downstream site in the catchment. The findings illustrate spatiotemporal patterns in precipitation and stream water isotopes and provide insight into mechanisms affecting their composition on sub-Antarctic Marion Island.