![Two scientists collecting rocks in Antarctica with GPS device](http://static.sciencelearn.org.nz/images/images/000/005/442/full/TheConversation_ART_RockClock_ShaunAndJamey.jpg?1715814067)
Dr Shaun Eaves and Dr Jamey Stutz collect rock samples at Byrd Glacier.
The yellow GPS device in the foreground records the precise location of samples – for example, latitude, longitude and elevation above sea level. Elevation is a key observation for the method as cosmogenic nuclide production rates increase with height (roughly 2 times for every 1 km).
Photo by Steve Grimes.