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Apparently not. They say the ice "is not organized into neat layers", so they have approximated the age based on potassium and argon concentration. Though it d
by diggernet 9y ago
Apparently not. They say the ice "is not organized into neat layers", so they have approximated the age based on potassium and argon concentration.
Though it doesn't mention what potassium and argon have to do with age. Short explanation, anyone?
- sir_kitty 9y agoIsotopes of potassium decay to argon and the amount of accumulated argon - combined with knowledge of the decay rate - allows one to use the system as a clock: https://en.wikipedia.org/wiki/K%E2%80%93Ar_dating https://en.wikipedia.org/wiki/K%E2%80%93Ar_dating
- jhawk28 9y agothat assumes you know how much it started with and what the environment was like then
- nitrogen 9y agoIt's safe to assume that these assumptions have been accounted for by the scientists developing and performing isotopic dating.
- greglindahl 9y agoThe Wikipedia page covers these issues, albeit for crystalized rock instead of ice. The measurement is a ratio, so the key thing is establishing that Argon 40 is normally not present in rain or brand new ice.
- EGreg 9y agoBut are there at least a million layers? I mean, there have to be some amount of well preserved cycles from the compaction of snowfall right? It would be very strange if ALL the ice was not organized!