News - May 2002
NSF PR 02-36
Dispatch 5, The coastal waters of Charcot Island
May 8, 2002 / the coastal waters of Charcot Island
-- A sense of accomplishment and anticipation pervaded
the Nathaniel B. Palmer as she steamed toward the
end of the SO GLOBEC survey grid this week, creeping
south below the 69th parallel.
With cold temperatures and good visibility, voyagers
got a lesson in the life cycle of ice. Moving from
open ocean toward Charcot Island, the Palmer passed
through several stages of new ice -- grease ice, nilas,
and pancake ice, then year-old pack ice, then finally,
today, into a garden of ice floes, icebergs, and scrappy
brash ice. The rapidly changing scenery told the story
of sea ice like time-lapse photography.
The sun peeked out at 10:20am this morning, revealing
a clear, beautiful day. Snow-covered ice in all shapes
and sizes, separated by rivers and pools of water,
glistened to the horizon, swathed in the sky's soft
"This is great for people like me who like to sleep
in," said Ana Sirovic, a graduate student from Scripps
Institution of Oceanography in La Jolla, Calif. "I
don't get to see so many sunrises when I'm home."
As the Palmer got closer to Charcot Island, the landscape
grew more and more spectacular. Passengers on the
bridge felt like they were on a museum tour or an
iceberg safari as they stared out the glass at a changing
wonderland of giant, chiseled ice sculptures. An iceberg
taller and thicker than the ship passed close by her
starboard side, looming over onlookers.
Even Palmer Captain Joe Borkowski, on his 56th voyage
to the Antarctic, said the scenery was unlike any
he'd ever seen. "Ice is a complex subject. You could
read all the books you want to learn about ice, but
every trip seems different."
By 2pm, the sun was already retreating from its short
journey, repainting the view with a new pattern of
striking shadows. By 4:30pm, the sky was just a low
wash of orange as the sun sped away and the moon appeared.
A view from the top of the food web
Deb Glasgow enjoyed the day's views from the ship's
ice tower, where she is observing marine mammals for
the International Whaling Commission (IWC).
"The bird boys think they've got the best spot on the
ship, but I think I've topped it," quipped Glasgow,
who climbs three ladders every morning to her tiny,
unheated room above the bridge. From her vantage point,
she can see the heads of seabird researchers Matt
Becker and Erik Chapman's in the "bird box," their
observation station, below her.
Glasgow is mapping the distribution of whales and seals
along the Palmer's survey grid. At the top of the
Antarctic food web, whales and seals are important
indicators of what's happening with animals lower
down, including krill.
"Where I am seeing large groups of whales, they're
also seeing krill on the BIOMAPER," Glasgow said.
"The information is tying up really well."
Glasgow spends a lot of time scraping ice and frost
off the ice tower windows. Visibility is critical
as she scans the ocean for whale blows.
"It's like a little puff of air coming from the ocean,
and from that I need to identify what kind of species
it is," she said. Whales have distinguishing blows;
for example, southern right whales make a V-shaped
blow and sperm whales blow along a 45-degree diagonal.
Glasgow is also an artist and photographer. Her visual
training allows her to pick out these tiny events
from the vast ocean. Artists and scientists share
the same keen powers of observation, she noted.
Glasgow is also trying to get photo ID's of individual
whales when they surface.
"Humpbacks have a white coloring on the underside of
the flukes that's quite individual, almost like the
fingerprints we have," Glasgow said. Southern right
whales can be identified by the unique pattern of
callosities -- rough, large, wart-like growths --
that they have on their heads.
By matching a photo ID taken in Antarctica with one
taken, for example, in Costa Rica, scientists can
track whale migration routes. During Antarctic summers,
whales migrate to the productive Southern Ocean to
feed. During the winter, they head north to warmer
climates to breed and raise their calves. Few whale
surveys have been done in Antarctica this late in
the year, Glasgow said. Sightings may be infrequent,
making for slow days in the observation tower.
"It takes an enormous amount of patience and commitment,
or you've got to be an extremely stubborn person,"
The singular sounds of cetaceans
Accustomed to working in a team of at least four observers
during busy summer cruises, Glasgow is still adjusting
to being the lone marine mammal observer on the Palmer.
"It's a bit like solitary confinement up here. That's
why I talk so much when I go downstairs," said Glasgow
with her marked Australian accent. Glasgow offers
her rare visitors tea from a thermos. "It's quite
civilized up here," she said.
Glasgow also gets help from a Palmer scientist who
is listening for whales. Down in the dry lab, where
the only views are through small portholes, Scripps
graduate student Ana Sirovic scans the ocean with
her ears. Sirovic uses "sonobuoys," single-use instruments
with a hydrophone, radiotransmitter, and antenna,
that she throws into the water periodically. Sonobuoys
capture underwater sounds which they relay to a receiver
on the Palmer and finally to a computer where Sirovic
is listening through headphones. She often hears the
elaborate songs of humpback whales.
At the same time, Sirovic can "watch" the sound on
her computer screen. Colorful pictures called spectrograms
display the frequency and intensity of the ocean sounds.
Different sounds have distinctive patterns. Sirovic
can visually distinguish earthquakes -- which she
picks up from all over the world -- from ship noises
from ice cracking from biological noises like seals
and whales. Moreover, she can tell what types of whales
are out there.
"Every species has a different type of call," Sirovic
said. "The frequency characteristics and the duration
of the call will tell you what species it is. You
can tell a blue whale from a fin whale from a humpback
from a killer whale." Many whale calls are too low
in frequency or too short to be heard by the human
ear, but can still be seen on the spectrogram.
"Then within each species' language there are also
dialects," Sirovic continued. Antarctic blue whales
sound differently than Pacific blue whales, for example.
Sirovic's goal is to learn enough about specific Antarctic
calls to make sense of two years worth of sound data
that she's been collecting from the bottom of the
Sirovic took part in an earlier SO GLOBEC cruise that
deployed eight "bottom instruments," more sophisticated
sonobuoys that record all the ocean's sounds for a
"Basically, we get to location, drop them in, and 11
months later it's got 27 gigabytes of data," Sirovic
said. The long-term sound data will help scientists
estimate the distribution, seasonality, and even population
sizes of Antarctic-going whales. Scientists are particularly
interested in how whale populations have changed since
Antarctic whaling moratoriums were established in
the Southern Ocean in the 1960's and 70's.
Working together to capture 'the big picture'
While Palmer scientists anxiously scanned the horizon
and listened to the seas for signs of life, scientists
on the Laurence M. Gould were in the thick of the
marine mammal action deep in Marguerite Bay.
"There was a conveyor belt of whales the whole day,"
said Ari Friedlaender of the IWC, describing one day
during which he saw more than 60 whales. Friedlaender,
like Glasgow, is counting whales, but along the Gould's
variable path instead of on a formal grid.
"We've seen more seals on a single floe this year than
we saw the whole time last year. We're very happy,"
said Mark Hindell of the University of Tasmania, Australia,
who is working with the Gould's seal group tagging
crabeater seals and collecting blood and scat samples.
Gould scientists hope to learn about the winter-feeding
strategies of crabeaters, which -- despite their name
-- feed chiefly on krill.
Data from last year's satellite tags showed the seals
to be diving unexpectedly deep in the winter. This
may mean they're supplementing their krill diet with
fish, said Jen Burns of the University of Alaska,
Anchorage. One tagged seal also gave birth to a pup,
allowing scientists to record a mother seal's foraging
The seal biologists climb right up on ice floes to
tag seals. "It's a lot of fun. You get to sit on the
ice floe, look around, and pet minke whales that swim
up next to the floe," Burns said.
The Gould scientists proudly show off close-up videos
of playing seals and breaching whales that they've
taken in the field.
Only slightly envious of their colleagues' exploits
on the Gould, scientists on the Palmer will leave
the cruise with a different, but complementary, account
of the Southern Ocean. While the Gould has captured
a dynamic and eye-catching excerpt of the Antarctic
ecosystem, the Palmer has methodically and patiently
pieced together an intricate and wide-ranging portrait.
"I think it's amazing that, in a few days, we'll have
a whole picture of what the area looks like," Sirovic
remarked. "Not just in whale distribution, but in
current structure, phytoplankton, nutrients, and everything."