Characteristics of the sticky spot of Kamb Ice Stream, West Antarctica

Tarun Luthra, Leo E. Peters, Sridhar Anandakrishnan, Richard B. Alley, Nicholas Holschuh, Andrew M. Smith

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Amplitude analysis of reflection seismic data reveals the presence of highly variable bed conditions under the main sticky spot and adjacent regions of the Kamb Ice Stream (formerly ice stream C). The sticky spot, which is a zone of bed that imparts high basal resistance to ice flow, is situated on a local topographic high composed of consolidated sediments or sedimentary rock. Any meltwater draining from upglacier along the base of the ice is routed around the sticky spot. The ice over the sticky spot includes, in at least some places, a seismically detectable basal layer containing a low concentration of debris, which locally thickens to 40 m over a topographic low in the bed. The ice-contact basal material ranges from dilated and highly porous to more-compacted and stiff, and perhaps locally frozen. The softer material is preferentially in topographic lows, but there is not a one-to-one correspondence between basal character and basal topography. We speculate that the 40 m thick frozen-on debris layer formed by glaciohydraulic supercooling of lake-drainage events along a basal channel during the former, active phase of the ice stream. We also speculate that loss of lubricating water, perhaps from piracy upstream, contributed to the slowdown of the ice stream, with drag from the sticky spot playing an important role, and with the basal heterogeneity greatly increasing after the slowdown of the ice stream.

Original languageEnglish (US)
Pages (from-to)641-653
Number of pages13
JournalJournal of Geophysical Research: Earth Surface
Volume122
Issue number3
DOIs
StatePublished - Mar 1 2017

Fingerprint

ice stream
Ice
Antarctic regions
Antarctica
ice
beds
piracy
supercooling
drainage
ice flow
debris
Debris
meltwater
drag
sedimentary rock
seismic data
topography
sedimentary rocks
Sedimentary rocks
Supercooling

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Space and Planetary Science
  • Earth and Planetary Sciences (miscellaneous)
  • Palaeontology

Cite this

Luthra, Tarun ; Peters, Leo E. ; Anandakrishnan, Sridhar ; Alley, Richard B. ; Holschuh, Nicholas ; Smith, Andrew M. / Characteristics of the sticky spot of Kamb Ice Stream, West Antarctica. In: Journal of Geophysical Research: Earth Surface. 2017 ; Vol. 122, No. 3. pp. 641-653.
@article{c01f690d91d1490eac91541a538325dd,
title = "Characteristics of the sticky spot of Kamb Ice Stream, West Antarctica",
abstract = "Amplitude analysis of reflection seismic data reveals the presence of highly variable bed conditions under the main sticky spot and adjacent regions of the Kamb Ice Stream (formerly ice stream C). The sticky spot, which is a zone of bed that imparts high basal resistance to ice flow, is situated on a local topographic high composed of consolidated sediments or sedimentary rock. Any meltwater draining from upglacier along the base of the ice is routed around the sticky spot. The ice over the sticky spot includes, in at least some places, a seismically detectable basal layer containing a low concentration of debris, which locally thickens to 40 m over a topographic low in the bed. The ice-contact basal material ranges from dilated and highly porous to more-compacted and stiff, and perhaps locally frozen. The softer material is preferentially in topographic lows, but there is not a one-to-one correspondence between basal character and basal topography. We speculate that the 40 m thick frozen-on debris layer formed by glaciohydraulic supercooling of lake-drainage events along a basal channel during the former, active phase of the ice stream. We also speculate that loss of lubricating water, perhaps from piracy upstream, contributed to the slowdown of the ice stream, with drag from the sticky spot playing an important role, and with the basal heterogeneity greatly increasing after the slowdown of the ice stream.",
author = "Tarun Luthra and Peters, {Leo E.} and Sridhar Anandakrishnan and Alley, {Richard B.} and Nicholas Holschuh and Smith, {Andrew M.}",
year = "2017",
month = "3",
day = "1",
doi = "10.1002/2016JF004181",
language = "English (US)",
volume = "122",
pages = "641--653",
journal = "Journal of Geophysical Research",
issn = "0148-0227",
publisher = "American Geophysical Union",
number = "3",

}

Characteristics of the sticky spot of Kamb Ice Stream, West Antarctica. / Luthra, Tarun; Peters, Leo E.; Anandakrishnan, Sridhar; Alley, Richard B.; Holschuh, Nicholas; Smith, Andrew M.

In: Journal of Geophysical Research: Earth Surface, Vol. 122, No. 3, 01.03.2017, p. 641-653.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Characteristics of the sticky spot of Kamb Ice Stream, West Antarctica

AU - Luthra, Tarun

AU - Peters, Leo E.

AU - Anandakrishnan, Sridhar

AU - Alley, Richard B.

AU - Holschuh, Nicholas

AU - Smith, Andrew M.

PY - 2017/3/1

Y1 - 2017/3/1

N2 - Amplitude analysis of reflection seismic data reveals the presence of highly variable bed conditions under the main sticky spot and adjacent regions of the Kamb Ice Stream (formerly ice stream C). The sticky spot, which is a zone of bed that imparts high basal resistance to ice flow, is situated on a local topographic high composed of consolidated sediments or sedimentary rock. Any meltwater draining from upglacier along the base of the ice is routed around the sticky spot. The ice over the sticky spot includes, in at least some places, a seismically detectable basal layer containing a low concentration of debris, which locally thickens to 40 m over a topographic low in the bed. The ice-contact basal material ranges from dilated and highly porous to more-compacted and stiff, and perhaps locally frozen. The softer material is preferentially in topographic lows, but there is not a one-to-one correspondence between basal character and basal topography. We speculate that the 40 m thick frozen-on debris layer formed by glaciohydraulic supercooling of lake-drainage events along a basal channel during the former, active phase of the ice stream. We also speculate that loss of lubricating water, perhaps from piracy upstream, contributed to the slowdown of the ice stream, with drag from the sticky spot playing an important role, and with the basal heterogeneity greatly increasing after the slowdown of the ice stream.

AB - Amplitude analysis of reflection seismic data reveals the presence of highly variable bed conditions under the main sticky spot and adjacent regions of the Kamb Ice Stream (formerly ice stream C). The sticky spot, which is a zone of bed that imparts high basal resistance to ice flow, is situated on a local topographic high composed of consolidated sediments or sedimentary rock. Any meltwater draining from upglacier along the base of the ice is routed around the sticky spot. The ice over the sticky spot includes, in at least some places, a seismically detectable basal layer containing a low concentration of debris, which locally thickens to 40 m over a topographic low in the bed. The ice-contact basal material ranges from dilated and highly porous to more-compacted and stiff, and perhaps locally frozen. The softer material is preferentially in topographic lows, but there is not a one-to-one correspondence between basal character and basal topography. We speculate that the 40 m thick frozen-on debris layer formed by glaciohydraulic supercooling of lake-drainage events along a basal channel during the former, active phase of the ice stream. We also speculate that loss of lubricating water, perhaps from piracy upstream, contributed to the slowdown of the ice stream, with drag from the sticky spot playing an important role, and with the basal heterogeneity greatly increasing after the slowdown of the ice stream.

UR - http://www.scopus.com/inward/record.url?scp=85017135000&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85017135000&partnerID=8YFLogxK

U2 - 10.1002/2016JF004181

DO - 10.1002/2016JF004181

M3 - Article

AN - SCOPUS:85017135000

VL - 122

SP - 641

EP - 653

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

SN - 0148-0227

IS - 3

ER -