Amy Leventer and Emily Constantine '03 on a more recent cruise
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From January 30 to March 29 2001, a team of 25 scientists, including Charlie McClennen
and Amy Leventer (Chief Scientist), and Colgate undergraduate geology majors
Natalie McLenaghan, Meredith Metcalf, and Caroline Olson, explored the East Antarctic
Margin on cruise NBP0101 of the RVIB Nathaniel B. Palmer. The Palmer is one of two
icebreakers leased by the National Science Foundation and is dedicated almost entirely
to conducting scientific research in the Southern Ocean. This 58-day cruise left from
Hobart Tasmania and returned to port in Capetown South Africa, after transiting nearly
a quarter of the way around the perimeter of Antarctica. Along the way, nearly a quarter
mile of sediment core was recovered from seven deep shelf basins, with the goal of
developing a record of climate and oceanographic change during the Quaternary. Although
the pace of recent climate change appears to be more rapid and of a larger scale in
Antarctica compared to other areas of the globe, the factors forcing climate change
in Antarctica are not well understood, due to the relative inaccessibility of the
southernmost continent and the inhospitable working conditions. In order to address
this scarcity of samples, particularly from the eastern side of the continent, we devoted
our two months of ship time to acquiring as much data as possible. Most of the sediment
core material was recovered with the "Jumbo Piston Corer," a 90-foot long, 5" diameter,
assembly of steel barrels, plastic core liner, and lead weights. Core sites were
selected based on a combination of sub-bottom profiling and seafloor bathymetric
mapping of well stratified and undisturbed acoustic reflectors. Back in the lab,
our group has been responsible for two lines of investigation. First, we develop
paleoenvironmental reconstructions based on microscopic analysis of diatoms, single
celled algae with a hard silica skeleton that serves as a permanent record of past
climate. Second, we work with the sea floor maps to decipher the geologic processes
that have shaped the seabed. Natalie, Caroline and Meredith worked with both Charlie
and Amy as well as with our colleagues from other institutions, on senior projects
based on the data collected during the cruise. Their contribution to the success of
this cruise has been invaluable. Geology undergrads will continue the detailed analysis
for the next few years as we extract the clearest indicators of Antarctic margin climate
change from the core samples.
Amy Leventer
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