3 ms·
> occurring precisely 14,300 years ago. …precisely? Really?
by greggsy 3y ago
> occurring precisely 14,300 years ago.
…precisely? Really?
- PaulHoule 3y agoYou can count individual tree rings, so yeah.
- medstrom 3y agoThe oldest living tree has seen 9,565 birthdays (https://en.wikipedia.org/wiki/Old_Tjikko https://en.wikipedia.org/wiki/Old_Tjikko), but it doesn't have 9,565 rings. Even if it did, there's a gap of at least a few thousand years ;-) I'm impressed they got it exact, but wasn't by ring-counting (only).
- thejoneser 3y agoNot necessarily. You can compare dead trees in the same vicinity that were alive at overlapping time intervals. Patterns in the width of the rings will reveal the period over which their lives overlapped. With enough dead trees, if they are preserved well enough, you could go back significantly further and age trees that are long dead.
- schrectacular 3y agoIt's called "Dendrochronology" and this is exactly how it is done. In the Northern Hemisphere they can date back at least 13,910 years.
- chrisco255 3y agoTrees turn into fossils too sometimes.
- medstrom 3y agoYou still have to figure out when it did. If there's a tree with 800 rings, but it died 100,000 years ago, then there's 100,000 years you have to date by some other method, and add 800 on top.
- greggsy 3y agoThat’s not how they got to that figure, which is 50% greater than the oldest known tree… (and I don’t think they even counted the rings for that one)
- Zitrax 3y agoFrom the abstract: "The resulting Δ14C record exhibits an abrupt spike occurring in a single year at 14 300–14 299 cal yr BP and a century-long event between 14 and 13.9 cal kyr BP."
- chrisco255 3y agoTree rings are pretty precise.