Understanding Antarctic Ice

Amundsen-Scott South Pole station

South PoleDome

Summer camp

road to work

Amundson-Scott South Pole

Questions about the ice

A. How cold the ice isB. How old the ice isC. How the ice movesD. How clean the ice is

Light traveling through ice

Object is blurred

Object isdimmer

scattering

absorption

What causes light scattering in ice?

1. Bubbles (trapped air) Q: As we go deeper, scattering by bubbles

A.gets stronger (worse)

B.gets weaker (better)

C.does not change

Why?

What causes light scattering in ice?

2. Dust particles

Q: As we go deeper, scattering by dust

Ans. varies wildly

What causes light absorption in ice?

3. Volcanic Ash

How do we know how much dust is in the ice?

Old school approach: take ice cores

How do we know how much dust is in the ice?

Measure twice, melt once

How old is the ice?(We don’t really need to know, but we can measure it.)

Ice flow at the South Pole

“South Pole” is marked every Jan 1

The ice surface moves byone inch per day = 9 m/yr

CNN

Nobody knows (yet) if bottom of ice sheet is dry (frozen) or wet (melted)