4 ms·
Isotopes 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:
by sir_kitty 9y ago
Isotopes 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.