From Tim Page
      stuck in the pack ice
      onboard RSV Aurora Australis
      Antarctica
      3rd December 1998, 2pm
 

Hello to everyone at Winthrop school, and of course to Ms Kelly in the Far East!
 

PRESENT POSITION:   69 degrees South Latitude, 75 degrees East Longtitude
DIRECTION HEADING:   None (stationary)
SPEED HEADING:   None (stationary)
DISTANCE FROM TASMANIA:  2889 nautical miles (3328 miles)
DISTANCE TO MAWSON STATION: 288 nautical miles (331 miles)
AIR TEMPERATURE:   -7 degrees Celsius (19 degrees Fahrenheit)
WATER TEMPERATURE:  -1.6 degrees Celsius (29 degrees Fahrenheit)
WATER DEPTH:   746 metres (2446 feet)
WIND SPEED:    11 knots (12.5 miles per hour)
 

Hi there everybody.  As you can probably tell from my latitude and longtitude, we have barely moved!  Hmmmm, well, many things are happening here at the moment.  We have had a teeny, tiny problem with the ship.  Well, actually, it's a great big problem!  The propeller is broken.  The propeller is in the water at the back of the ship and looks like a great big fan.  It pushes the ship through the water.  Well it is supposed to push the ship, at the moment it is doing nothing.  The engineers are trying to fix it.  If they can't, then we have to find another way of getting home!  There is a chance that we will be able to hitch-hike on a passing Chinese, Japanese or Russian ship, but we don't really know at the moment.  If we do, at least we will get to try some interesting new food!

There is some open water off the stern (back) of the ship, where we we able to break a passage through the ice.  Since there is very little open water around here, some animals have taken advantage of the fact that we have made a channel and use it get into and out of the water.  So they are happy that we are here.  A couple days ago there were dozens of little Adelie penguins swimming just off our stern, fishing for krill.  They all moved together like little dolphins "porposing" through the water.  There were also a few bigger Emperor penguins fishing with them.  They all jumped out of the water onto the ice and were standing right next to the ship.  Then we saw a great big reptile-like head stick out of the water, look carefully around, and sink back in.  It was a Leopard seal looking for a meal!  It jumped out of the water near the penguins, but since Leopard seals don't move very fast on land, it didn't catch anything.  It slithered back into the water, chased by some very annoyed penguins!  Later on we saw some penguins in the distance shoot out of the water like mini rockets!  We guessed the seal was after them, and so it turned out as we then saw a seal flinging a penguin into the air.  Poor penguin, but a seal has to eat too.

We have also seen another type of seal here, called a Weddell seal.  They are big and fat, and are dark with white spots.  They have a small face that looks a bit like a smiling Cheshire cat.  They tend to live very deep in the ice, near land.  We saw one up close on the ice near Davis Station.  It made a beautiful trill bird-like sound when we were close, which is its way of saying "back off, buddy", which we did.  They also make sounds underwater.  Males defend a certain patch of water under the ice, and use the sounds to tell the other male seals "this is my territory, buzz off" and to tell the female seals "come over to my place, baby".

In fact sound is a great way to communicate under water, since seeing underwater can be a problem.  Another animal that uses sound underwater a lot is the humpback whale, which sings "songs".  My friend, Mike, is a researcher from Sydney University who studies the songs that whales sing, and is an expert on sound underwater.  Here's what he has to say about it:

"Sound in the ocean

Sound in water travels five times as quickly as it does in air. It also travels much further and some loud sounds can travel for hundreds or even thousands of miles. Light though does not travel very well in water at all. If you put on some goggles in the sea you can only see things a short distance away compared to seeing things in air. Because sound travels further in water than light does, many animals that live in the ocean use sound to 'see' rather than light.

Whales and dolphins are mammals that live in the ocean. Some whales, like the humpback whale, can tell what is around them by listening to sounds. They can hear waves crashing on the beach and noisy shrimp that live on reefs. They also make sounds of their own. These sounds are long beautiful songs that the males sing to show off to the females. Other whales can hear the song even though they are many miles away from the singer and cannot see them.

Dolphins and some other whales use sound in a different way. They make their own short clicking sounds which travel through the water and bounce off underwater objects like echoes bouncing off a cliff. The dolphin can hear these echoes and tell how far away the object is. It also tells the dolphin what shape the object is and so the dolphin can 'see' the object using sound. This is called 'echolocation' or 'sonar'."

Do you remember the that the Sperm Whale I mentioned a few letters ago also uses echolocation?  Thanks for the Mike, that was interesting!

Looks like we could be here for a while!  I'll let you know what happens.

Have fun!
 

Tim Page