Continent Study: Antarctica – How do animals survive the sub-zero temperatures?

antarctic-button

Antarctica doesn’t have the diversity of wildlife that other continents have.  Those animals which are able to survive the sub-zero temperatures do so because they have adapted to this environment to reduce heat loss, often developing warm windproof coats and layers of blubber.  We did an experiment to investigate how blubber helps to keep an animal warm.

What is blubber?

Elephant Sealblubber

 Picture Credit

Blubber is a thick layer of fat or adipose tissue found directly underneath the skin of all marine mammals, covering their entire body except for fins and flippers.  It has three main functions.  It keeps in the body heat of the mammal; it helps to make the mammal more buoyant and it stores up energy for the months when food is hard to come by.

Blubber as an insulating material works because it contains a network of blood vessels which constrict when the mammal is in cold water.  This means the mammal’s circulating blood remains on the inside of the blubber and is therefore protected from the coldness of the water.

An experiment to investigate the insulating properties of blubber

What did we do?

T13, who opted to lead this experiment, gathered together icy cold water, latex gloves and Vaseline.  The Vaseline was used to mimic the effects of blubber.  He explained to his young scientists what they were going to do.  He helped them on with a glove each and asked them to hold the gloved hand in the icy water for as long as they could:

Ribbet collageblubber1

The girls did as they were bid.  To protect their lab coats T pulled the gloves up and over their sleeves:

Ribbet collageblubber2

The time was recorded on the white board:

DSC_0413blubber

T then smothered their gloved hands thickly in Vaseline….

DSC_0411blubber

…..and they then repeated the experiment by holding their gloved and Vaselined hands in the water for as long as they could:

Ribbet collageblubber3

What did the girls think would happen?

The girls both predicted they would be able to hold their hand in the water for longer with the Vaseline on.  A6 stated that wearing the Vaseline would be like wearing a warm glove in cold weather.

What actually happened?

The girls held their hands in the icy water for 27 seconds without the Vaseline.

The girls held their hands in the icy water for 42 seconds with the Vaseline.

Why did this happen?

A6 commented that the Vaseline stopped the icy water from touching her hands.  T wondered did the Vaseline prevent loss of heat from the hand to the icy water, therefore making the hand comfortable in the icy water.

The Vaseline actually formed an insulating layer over the hand, preventing the icy water from cooling the circulating blood in the hand.  This meant the hand did not feel the icy water in the same way it did without the Vaseline, allowing the hands to be held in the water for longer.

13 comments

  1. We tried something similar with sandwich bags and shortening- it’s such a great hands on experiment to learn about blubber! (I miss those days 🙂 ) Fun to see T working with the girls for this – they really are so cute in their lab coats!

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