Discovery of relict subglacial lakes and their geometry and mechanism of drainage


Autoria(s): Livingstone, Stephen J.; Utting, Daniel J.; Ruffell, Alastair; Clark, Chris D.; Pawley, Steven; Atkinson, Nigel; Fowler, Andrew C.
Data(s)

01/06/2016

Resumo

Recent proxy measurements reveal that subglacial lakes beneath modern ice sheets periodically store and release large volumes of water, providing an important but poorly understood influence on contemporary ice dynamics and mass balance. This is because direct observations of how lake drainage initiates and proceeds are lacking. Here we present physical evidence of the mechanism and geometry of lake drainage from the discovery of relict subglacial lakes formed during the last glaciation in Canada. These palaeo-subglacial lakes comprised shallow (<10 m) lenses of water perched behind ridges orientated transverse to ice flow. We show that lakes periodically drained through channels incised into bed substrate (canals). Canals sometimes trend into eskers that represent the depositional imprint of the last high-magnitude lake outburst. The subglacial lakes and channels are preserved on top of glacial lineations, indicating long-term re-organization of the subglacial drainage system and coupling to ice flow.

Formato

application/pdf

Identificador

http://pure.qub.ac.uk/portal/en/publications/discovery-of-relict-subglacial-lakes-and-their-geometry-and-mechanism-of-drainage(c0f78ae1-4d6a-4adf-9780-c42b4aed76f5).html

http://dx.doi.org/10.1038/ncomms11767

http://pure.qub.ac.uk/ws/files/73093329/Discovery_of_relict_subglacial_lakes_and_their_geometry_and_mechanism_of_drainage.pdf

Idioma(s)

eng

Direitos

info:eu-repo/semantics/openAccess

Fonte

Livingstone , S J , Utting , D J , Ruffell , A , Clark , C D , Pawley , S , Atkinson , N & Fowler , A C 2016 , ' Discovery of relict subglacial lakes and their geometry and mechanism of drainage ' Nature geoscience , vol 7 , 11767 . DOI: 10.1038/ncomms11767

Tipo

article