Antarctic Glaciologists Honored by ACAN
At its January 2003 meeting, the Advisory Committee for
Antarctic Names (ACAN) honored eleven glaciologists who have long been
associated with studies of ice streams entering the Ross Ice Shelf from
the West Antarctic Ice Sheet. The name changes are as follows.
OLD NAME/ NEW NAME
Ice Stream A / Mercer Ice Stream
Ice Ridge AB / Conway Ice Ridge
Ice Stream B1 / Van der Veen Ice Stream
Ice Ridge BC / Engelhardt Ice Ridge
Ice Stream C / Kamb Ice Stream
Ice Ridge CD / Raymond Ice Ridge
Ice Stream D / Bindschadler Ice Stream
Ice Ridge DE / Shabtaie Ice Ridge
Ice Stream E / MacAyeal Ice Stream
Ice Ridge EF / Harrison Ice Ridge
Ice Stream F / Echelmeyer Ice Stream
Click here for a MAP with the new names
The ACAN action followed a decision it made in 2001 to
have Ice Stream B renamed Whillans Ice Stream, in honor of Ian M.
Whillans, who died on 9 May 2001 at the height of his distinguished
glaciological career. Ian was among the first to study these West
Antarctic ice streams and he made major contributions to understanding
their dynamics thereafter, most notably on Whillans Ice Stream.
Shortly after radio-echo sounding was introduced in
Antarctica, radio-echo flights during the 1969-1970 austral summer
identified five ice streams that entered the Ross Ice Shelf from the
West Antarctic Ice Sheet. These were named ice streams A through E by
the investigators, all from the Scott Polar Research Institute in
Cambridge, England (1). Landsat satellite imagery soon disclosed the
location of another ice stream north of ice stream E, which was called
ice stream F (2). These discoveries closely followed the discovery by
John Mercer that the West Antarctic Ice Sheet had been much larger in
the past, a conclusion he reached after mapping lateral moraines up to
2000m above the foot of Reedy Glacier (3). Reedy Glacier is the main
East Antarctic tributary of old ice stream A, which mostly drains West
Antarctic ice, so the high moraines had to result from thicker West
Antarctic ice. Then, in 1972, Ian Whillans re-surveyed the Byrd Station
Strain Network, which went from old Byrd Station to the West Antarctic
ice divide. Ian found that the ice surface was lowering, with lowering
increasing downslope (4). This indicated that the surface lowering
reported by Mercer was still going on.
The l970s was the decade of the Ross Ice Shelf Project
(RISP). Under that umbrella, the University of Wisconsin under the
direction of Charles Bentley conducted the Ross Ice Shelf Geophysical
and Glaciological Survey (RIGGS). When RISP was complete, much of the
RIGGS team extended the same measurements, notably seismic and radar
mapping, across the grounding line of the Ross Ice Shelf and onto the
West Antarctic Ice Sheet. Sion Shabtaie was a major part of that team.
His collaboration with Bentley led to many seminal papers, among which
was mapping the surface and thickness of ice streams A through C, and
intervening ice ridges AB and BC (5). Their work was done under the
umbrella of the Siple Coast Project (SCP) in the 1980s, which became
the West Antarctic Ice Sheet Initiative (WAIS) in the l990s, largely
under the direction of Robert Bindschadler at the NASA/Goddard Space
Flight Center. He chaired the working group that produced the WAIS
Science and Implementation Plan for the National Science Foundation
(6), and he has chaired the annual WAIS workshops ever since.
A critical component of the WAIS Science and
Implementation Plan was drilling through some of the West Antarctic ice
streams. This was done by Barclay Kamb and Hermann Engelhardt, from the
California Institute of Technology, who focused attention on ice
streams B and C. Their studies included developing new drilling
technology and instrumentation of boreholes (7) and led to a new
understanding of the role of subglacial till in the fast motion of ice
streams (8). Drilling was also conducted through Siple Dome, which was
at the end of ice ridge CD. Charles Raymond correctly interpreted
radio-echo stratigraphy of Siple Dome and, perhaps more importantly,
developed a theoretical model for heat flow in and migration of shear
zones between ice ridges and ice streams (9). Modeling has always been
an important WAIS objective. Cornelis van der Veen, often in
collaboration with Ian Whillans, has been a major presence in modeling
West Antarctic ice streams. Their original approach to the force
balance in ice streams is gaining wide acceptance (10). Douglas
MacAyeal has also made major contributions to ice-stream modeling,
first for stream B, but most significantly for ice stream E. In
modeling ice stream E, MacAyeal used control methods to determine the
effect of a "sticky spot" on the ice velocity (11). Sticky
spots are viewed as exerting a major control on the flow and stability
of West Antarctic ice streams. Keith Echelmeyer and Wiliam Harrison
have also focused their field and theoretical research on the stability
of West Antarctic shear margins between ice streams and ice ridges,
with application to the migration of the shear margin of ice stream B
(12). They brought to their research on West Antarctic ice streams, a
knowledge of fast glacier flow from their collaboration on Jakobshavns
Isbrae in Greenland, and on surging Alaskan glaciers.
The first comprehensive study of an ice ridge is being
conducted by Howard Conway on ice ridge AB. His study is nearing
completion and will be our first insight into the long-term stability
if ice ridges between West Antarctic ice streams.
This brief overview can only give a flavor of the size
and scope of research that has been conducted on West Antarctic ice
streams and ice ridges by the glaciologists honored by ACAN. They are
representative of a very large group of scientists who have worked in
this part of West Antarctica, all of whom are deserving of recognition
by ACAN. Most of them are young and that recognition will come as WAIS
research moves into the Amundsen Sea sector of the West Antarctic Ice
.1. G.deQ. Robin, S. Evans, D.J. Drewry, C.H. Harrison, and D.L.
Petrie, 1970. Radio-Echo Sounding of the Antarctic Ice Sheet, Antarctic
Journal of the United States, vol. 5, no. 6, p. 229-232.
2. T. Hughes, 1973. Is the West Antarctic Ice Sheet Disintegrating?
Journal of Geophysical Research, vol. 78, no. 33, p.7884-7910.
3. J.H. Mercer, l968. Glacial geology of he Reedy glacier area,
Antarctica. Bulletin of the Geological Society of America, vol. 79, p.
4. I.M. Whillans, 1973. State of equilibrium of the West Antarctic
inland ice sheet. Science, vol. 182, p. 476-479.
5. S. Shabtaie and C.R. Bentley, 1988. Ice-thickness map of the West
Antarctic ice streams by radar sounding. Annals of Glaciology, vol. 11,
6. R.A. Bindschadler (editor), 1995. West Antarctic Ice Sheet Science
and Implementation Plan. U.S. National Science Foundation, 75 pages.
7. H. Engelhardt, B. Kamb, and R. Bolsey, 2000. A hot-water ice-coring
drill. Journal of Glaciology, vol. 46, no. l53, p. 341-345.
8. B. Kamb, 2001. Basal Zone of the West Antarctic Ice Streams and its
Role in Lubrication of Their Rapid Motion. The West Antarctic Ice
Sheet: Behavior and Environment, edited by R.B. Alley and R.A.
Bindschadler, Washington, DC, American Geophysical Union, Antarctic
Reseaerch Series, vol. 77, p. l57-l99.
9. C.F. Raymond, 1996. Shear margins in glaciers and ice sheets.
Journal of Glaciology, vol. 42, no. 140, p. 90-102.
10. C.J. van der Veen and I.M. Whillans, 1989. Force budget: I. Theory
and numerical methods. Journal of Glaciology, vol. 35, no. 119, p.
11. D.R. MacAyeal, 1992. The basal stress distribution of ice stream E,
Antarctica, inferred by control methods, Journal of Geophysical
Research, vol. 97, series B1, p. 595-603.
12. K.A. Echelmeyer and W.D. Harison, 1999. Ongoing margin migration of
Ice Stream B, Antarctica. Journal of Glaciology, vol. 45, no. 150, p.
Thanks to Terry Hughes for the above write-up.