Evidence for the long-term sedimentary environment in an Antarctic subglacial lake
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Lakes beneath the Antarctic Ice Sheet are of fundamental scientific interest for their ability to contain unique records of ice sheet history and microbial life in their sediments. However, no records of subglacial lake sedimentation have yet been acquired from beneath the interior of the ice sheet, and understanding of sediment pathways, processes and structure in subglacial lake environments remains uncertain. Here we present an analysis of seismic data from Subglacial Lake Ellsworth, showing that the lake bed comprises very fine-grained sediments deposited in a low energy environment, with low water- and sediment-fluxes. Minimum sediment thickness is 6 m, the result of prolonged low sedimentation rates. Based on the few available analogues, we speculate this sediment age range is a minimum of 150 ka, and possibly >1 Ma. Sediment mass movements have occurred, but they are rare and have been buried by subsequent sedimentation. We present a new conceptual model of subglacial lake sedimentation, allowing a framework for evaluating processes in subglacial lake environments, and for determining future lake access locations and interpreting subglacial lake samples.
Date Issued
2018-12-15
Date Acceptance
2018-10-07
Citation
Earth and Planetary Science Letters, 2018, 504, pp.139-151
ISSN
0012-821X
Publisher
Elsevier
Start Page
139
End Page
151
Journal / Book Title
Earth and Planetary Science Letters
Volume
504
Copyright Statement
© 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Sponsor
Natural Environment Research Council (NERC)
Grant Number
NE/G00465X/3
Subjects
Science & Technology
Physical Sciences
Geochemistry & Geophysics
Subglacial Lake Ellsworth
glaciology
active-source seismology
sedimentary environment
ice sheet
Antarctica
WEST ANTARCTICA
ICE-SHEET
SEISMIC OBSERVATIONS
MARINE-SEDIMENTS
EAST ANTARCTICA
STABILITY
ELLSWORTH
WHILLANS
HOLOCENE
STREAM
02 Physical Sciences
04 Earth Sciences
Publication Status
Published
Date Publish Online
2018-10-18