ANTARCTICA ON THE MOVE #5

from Tim Page

on the Australian Icebreaker "Aurora Australis", in the fast ice off Mawson

Station

January 5, 2000, 7:00pm (that's noon in Greenwich, England & 7am in New

England)

Hello there to the students and staff of Doyon, Winthrop and Block Island

Schools!

PRESENT POSITION: 67 degrees South Latitude, 62 degrees East Longitude

DIRECTION HEADING: -

SHIP SPEED: -

DISTANCE FROM TASMANIA: 3260 nautical miles

DISTANCE TO MAWSON STATION, ANTARCTICA: 10 nautical miles

AIR TEMPERATURE: - 1.3 degrees Celsius

WATER TEMPERATURE: - 1.1 degrees Celsius

WIND SPEED: 7.5 knots

HUMIDITY: 85%

Happy New Year/Century/Millennium!! Well, some people say that it's not

really a new century or millennium, but I think that it is, and since I'm

writing this, I guess I'm right. Actually we had an amazing New Year's Eve.

The ship was in really thick ice, so the Captain, Tony, decided to park it

there, just like a car. He pushed the ship into the ice, and lowered a rope

ladder, so we could go and play on the ice. The ice had many small hills

and pressure ridges, which are made when wind and water currents push sea

ice together. Now these little hills are very good for hiding behind when

you want to bean somebody with a snowball, which I did to my boss, Colin!

We decided the ice would be a magic place to spend New Year's Eve, so we

built some tables out of ice and snow to put our drinks and food on.

Melissa, one of the sealos, made some amazing snow sculptures of seals. She

made a life sized Crabeater, Leopard and Ross Seal! We even had some

party-crashers; lots of Adelie penguins wandered around having a look. They

were, of course, dressed very formally, but they didn't bring any of their

own drinks! Just as it neared midnight, the ship blew five loud blasts from

its horn, and someone rang a bell that was suspended over the side of the

ship from a crane. Because it is summer in the Southern Hemisphere and

because we are so far south, it was completely light at midnight, in fact I

got a bit sunburned from the light reflecting off the snow. Also, because

we are further east than you, we celebrated the New Year 12 hours before you

did, so when we were toasting the year 2000 on the ice with champagne, it

was still only noon where you were!

So you see, where you are on the globe effects what time it is and even what

season it is. Have you ever noticed that when you look at the globe that

some of the continents seem to fit together a bit like a giant jigsaw

puzzle? Especially the west coast of Africa and the east coast of South

America. Well guess what, it's no coincidence. You see the continents are

actually on giant plates that move, only an inch or two every year, but over

millions of years they go all over the globe. This is called Continental

Drift. You know how there are seven continents now? Well this hasn't

always been the case. A very long time ago there were only two, a northern

one called Laurasia and a southern one called Gondwana. Laurasia contained

what later became North America, Europe and Asia.

And importantly for this story, Gondwana contained Antarctica, Australasia,

South America, Africa and India. Geologists (people who study rocks) can

compare the type of rock in Antarctica and the other Gondwanan continents to

show that they are the same. Palaeontologists (people who study animal

fossils) can also tell they were once joined because there are fossils of

the same animals on what are now different continents, like a reptile called

Lystrosaurus that couldn't cross oceans. Palaeobotanists (people who study

fossilised plants and pollen) can also show fossils of the same plants. In

fact you can even see the relationship in plants and animals alive today,

like the Antarctic Beech Tree, which is in Australia, New Zealand, southern

Chile and in fossils in Antarctica.

Another interesting thing that has changed is the climate. In the past

Antarctica was not a cold place, in fact it was warmer than New England is

today, both on land and at sea. We can tell this by the fossils of warmth

loving plants and animals that we find in the Antarctic rock, like dolphins,

and even trees high up in the mountains, when now there are no trees

anywhere on the continent. There is coal in Antarctica, and since coal is

made from very old trees all smushed up, there must have been forests here.

The temperatures have changed many times, but Antarctica finally became a

cold place when the old continent of Gondwana began to come apart.

South America, Africa, Arabia and India all broke off and went there own way

thanks to the tectonic plates moving. India crashed into the bottom of Asia

and formed the high Himalaya Mountains. Australia was the last to break

off. It was attached along the Antarctic coastline that we have been past

on this voyage. If you look at the south coast of Australia, you can see

how it fits together.

When Australia moved away, it opened up a strait between it and Antarctica,

and since there was now no land attached, a strong water current formed

around the continent (called the Circumpolar Current). The cold water

helped to keep the continent separate from warm water near the equator and

so the water started to freeze, huge ice caps formed on the land, and

animals had to adapt to the new conditions or go extinct. Scientists can

tell more recent temperature changes by drilling very deep holes (called ice

cores) in the ice cap and bringing up a huge pillar of ice (like a giant

lollypop), with the oldest ice at the bottom. By studying the gases and

compounds dissolved in the ice, they can show how the climate changed.

OK, OK, I hear you say, enough about rocks, tell us something about animals!

Fair enough. A few days ago we stopped off at Davis Station, which is an

Australian base on the continent. We parked up in the fast ice, which, by

the way, is thick ice that is stuck fast to land. We jumped over the side

and went for a 'jolly' (an Antarctic term meaning 'a fun trip'). We

There are thousands upon thousands of these little guys there. Last year I

was there a little earlier in the season and so the birds were sitting on

eggs. Well this year there are chicks, lots and lots of them. They are

incredibly cute little grey fluff balls that hide under their parents and

keep warm. The parents alternate in walking across the ice to the open

water and catching some food to bring back to feed junior. Skuas fly

overhead looking for any stray chicks to eat, but they didn't have any luck

while I was there.

We were parked in the ice for a few days around New Year's Eve. We had some

good jollies there. A bunch of us flew in a helicopter to Sansom Island to

help restock a fuel depot. It was great to finally get there, because last

year we were stuck in the ice for a month right near here, but we never got

to see the island. This high, rocky island is completely surrounded by sea

ice, and you get a great view over the polar ice cap and Amery Ice Shelf,

which is an enormous flat, white expanse of ice. An ice shelf is where a

glacier flows out over the sea, so the whole thing is actually floating on

water! Some people flew onto the Amery itself, where they drill ice cores.

Some important people (and one important clam) even got to go to the Russian

Progress II Base and the Chinese Base, Zhong Shan.

We saw another amazing thing while parked in the ice. An enormous pod of

Killer Whales (Orcas) swam right past the stern of the ship. There were big

black fins everywhere and little white puffs of air and water when they

breathed. The Whalos (whale experts) onboard figured there may have been as

many as 60 whales at once!! Three very sensible Emperor Penguins, two

adults and one juvenile, popped out of the water just as the whales went

past and had a bit of a rest on the ice. I think the penguins must've

realised that 60 whales can get pretty hungry.

In fact, we've seen piles of whales this year, even great big Sperm Whales.

The head whalo onboard, Ari, is from Connecticut. He even used to work at

the Mystic Aquarium. He now lives in North Carolina, but comes down to

Antarctica to help the Australian Antarctic Division with whale surveys.

Here's what he has to say about his work:

'One of the scientific endeavors taking place on Voyage 4 is whale

observation. Known as WHALOS, these 4 people keep watch and record all

whale and dolphin sightings throughout the trip. They record exactly where

and when, what type, how many, the animal's behavior, and specific remarks

about the habitat (amount and type of ice cover). They also photograph and

take video footage when possible to have a better record of what they have

seen. All of these bits of data are used in a large-scale ecosystem

monitoring program being conduced in the Southern Ocean.

'Whales are one part of the Antarctic ecosystem, and by monitoring their

abundance, distribution, and population trends, we can better understand or

detect perturbations (disruptions), mostly man-made, to the system. In this

way, whales are a good indicator of the 'health' of the ecosystem. A second

aim of this particular cruise was to get a better understanding of what

types and how many whales were spending time in the summer pack ice. To

date, most summer work has been done around the ice edge, so this transect

through the pack ice offers a unique opportunity to understand summer whale

distribution in the pack ice. These data can then be used by managers

(International Whaling Commission) to generate more accurate population

estimates, and therefore more educated decisions about how these animals

should be managed or conserved.

'Most of the large, baleen whales in the Southern Hemisphere migrate to

Antarctica in the Austral (southern) summer to feed. These whales include

the blue, fin, humpback, right, sei, and minke. While the blue whale is the

largest of all whales (and all animals ever, for that matter), the minke

whale is the most abundant, and the most commonly seen on surveys. All of

these whales feed on krill, which occur in huge swarms around the continent

in the summer, when the conditions are favorable. Along with minke whales,

killer whales (orcas) are the only whales that spend the entire year in

Antarctica. The killer whales feed mostly on seals and penguins, and can

commonly be seen cruising around the ice looking for a meal.

'So far on Voyage 4, we have seen almost 200 whales. Most of the sightings

have been of minke whales. We have seen several orcas, including a

spectacular group of 60 animals while we were in the fast ice at the Amery

Ice Shelf. We have also seen humpback, sei, fin, and sperm whales.'

Thanks Ari, that was great. So you see, there are many surveys happening

from our ship, not just our seal survey. There are also a couple people

doing a bird survey (guess what they are called,  birdos!).

RESEARCH QUESTION

---------------------------------

To continue the whale theme, can you find out what kind of whales there are

in the waters near you? Do you know what season they are there? Where do

they migrate to when they aren't off the coast of New England? Why do they

migrate?

Hey guess what, the Antarctic Division now have a small website devoted to

our voyage. You can find it at this incredibly long address:

http://www.antdiv.gov.au/s/f.plx?/resources/eyewitness/V4_9900/Index.html

There will be new stuff added every week or so. Bye now.

TIM PAGE