January 2010 Earth Science Week Calendar Activity: Ice Core Clues.

Download Ice Core Clue card photographs here:

• Radioactivity

• Air Pollution

• Sodium

• Snowfall Layers

• Oxygen and Hydrogen Isotopes

• Vocanic Sulfate

• Carbon Dioxide and Methane

* “Sodium” graph adapted from Kreutz, K.J., Mayewski, P.A., Meeker, L.D., Twickler, M.S., Whitlow, S.I. and Pittalwala, I.I., in press 1997, Bipolar changes in atmospheric circulation during the Little Ice Age, Science. All other photographs and graphs are public domain.