20 ms·

Tree rings

by inemesitaffia 11mo ago

Tree rings

onionisafruit 11mo ago
Indeed, but the headline evoked the other image in my flu addled brain.
- pfannkuchen 11mo ago
  New marijuana euphemism just dropped.
kabdib 11mo ago
I was hoping for a secret society of volcano watchers, handing down carefully guarded records from generation to generation . . . ("There's nothing written in here, Dad")
- stonecharioteer 11mo ago
  Robert Langdon intensifies.
sfn42 11mo ago
I doubt there are any 12000 year old trees near the volcano.
- defrost 11mo ago
  How about 12,000 years of overlapping ring patterns from paleo trees? Live trees, dead trees in buildings, bogs, tidal zones, etc. There's also sedimentation layers from multiple scattered bore samples that will reveal more about patterns of particle fall from the skies and layered flows from years past.
  - sfn42 11mo ago
    I specifically meant live trees, didn't really occur to me that dead trees could be relevant. Not sure how common it is to find 12000 year old dead trees either but I guess it's more common than live ones. And of course geological surveys would definitely tell you something about the past
    - defrost 11mo ago
      Oak and other trees, felled several thousand years ago and used as trackway posts, in buildings, etc are the bread and butter of * https://en.wikipedia.org/wiki/Dendroarchaeology https://en.wikipedia.org/wiki/Dendroarchaeology Art historians often look at the wood panels of paintings that are 400 years or more old. You might enjoy reading the general overview: https://en.wikipedia.org/wiki/Dendrochronology https://en.wikipedia.org/wiki/Dendrochronology and, ahh, drilling deeper into the onion rings. The real problem with tree rings here in this specific case is ... Ethiopia .. not a lot of big trees now, nor in the recent past when it was grasslands - but not really my field - there's likely to be very slow growing unassuming trees that are surprisingly old there .. and remains of older trees that have overlapping ring sequences. But yes - geological / geophysical clues are likely more relevant here.
  - bit1993 11mo ago
    Literally reverse engineering.
  - SideburnsOfDoom 11mo ago
    > How about 12,000 years of overlapping ring patterns from paleo trees? Near this specific volcano? In a dry, "sparsely vegetated" region (1). Not a chance. https://en.wikipedia.org/wiki/Afar_Region#Land_features https://en.wikipedia.org/wiki/Afar_Region#Land_features
    - defrost 11mo ago
      Thank you for your thoughts. I addressed this an hour or so prior to your comment here: https://news.ycombinator.com/item?id=46146345 https://news.ycombinator.com/item?id=46146345 and would point out that Ethiopa (which I've visited, along with many other countries as part of my work in geophysical surveying) is famous for its Acacia trees: https://www.alamy.com/typical-ethiopian-landscape-with-acacia-trees-image353085193.html https://www.alamy.com/typical-ethiopian-landscape-with-acaci... This particular fact somewhat undercuts your strong assertion: > Not a chance. as there are actual well documented trees in the region that do form annual rings. The Afar isn't solely vegetated by Dracaena ombet which lack annual rings. https://en.wikipedia.org/wiki/Dracaena_ombet https://en.wikipedia.org/wiki/Dracaena_ombet
      - SideburnsOfDoom 11mo ago
        > This particular fact somewhat undercuts your strong assertion: My strong assertion, was not "there are no trees". Of course there are some trees of some size in some places. Not the same as an oak forest, but still. My strong assertion was regarding how very unlikely "12,000 years of overlapping ring patterns" would be from the sparser and smaller and less long-lived vegetation.
        defrost 11mo ago
        You might want to look deeper into the links I provided re: dendrochronology. There's no necessity for 12K years of volcano adjacent tree ring sources, any more than there's a requirement that the current immediate vicinity have many trees. I can leave that for you to ponder, it's not hard to fathom why. The scope of volcano eruption also comes into play, of course, there's a bunch of papers about tree rings and evidence of volcanic eruption wrt: The Black Death (1347 - 1353) in Europe with a wide separation between volcano and tree ring sites. On a tangential note, of all the trees in all the arid places about the globe, these are some of my favourites: https://www.snexplores.org/article/carvings-australia-boab-trees-lost-history-first-nation https://www.snexplores.org/article/carvings-australia-boab-t... and https://theconversation.com/the-boab-trees-of-the-remote-tanami-desert-are-carved-with-centuries-of-indigenous-history-and-theyre-under-threat-191676 https://theconversation.com/the-boab-trees-of-the-remote-tan.... The Tanami's tough country, it's where the last people (known) to first encounter "western" civilisation walked out from. It's where several of them returned after a few years of exposure.( https://www.bbc.com/news/magazine-30500591 https://www.bbc.com/news/magazine-30500591 ) Do you have any stories of your time in the Ethiopian Afar that provide first hand field experience for your strong assertion? Getachew Eshete and Göran Ståhl did some work there in 1999 in the Rift Valley part of the Afar region that indicated Acacia growth rings can be used as climate indicators for the 30 year life span periods of the wood studied.
- SideburnsOfDoom 11mo ago
  I doubt there are any trees near the volcano, full stop. Do the basics: go to google maps, find the "Hayli Gubbi volcano", click for the satellite image. Not a forested area at all. I can see some light greenery near Lake Bakili. But not much. "The Afar Region as a whole is sparsely vegetated" - https://en.wikipedia.org/wiki/Afar_Region#Land_features https://en.wikipedia.org/wiki/Afar_Region#Land_features
SideburnsOfDoom 11mo ago
What trees? Near this specific volcano, not in a forest but in a dry, "sparsely vegetated" region (1). I don't expect any substantial trees at all. Google maps has the satellite imagery, it's pretty rocky and barren. https://en.wikipedia.org/wiki/Afar_Region#Land_features https://en.wikipedia.org/wiki/Afar_Region#Land_features

Tree rings

onionisafruit 11mo ago

Indeed, but the headline evoked the other image in my flu addled brain.

pfannkuchen 11mo ago
New marijuana euphemism just dropped.

kabdib 11mo ago

I was hoping for a secret society of volcano watchers, handing down carefully guarded records from generation to generation . . . ("There's nothing written in here, Dad")

stonecharioteer 11mo ago
Robert Langdon intensifies.

sfn42 11mo ago

I doubt there are any 12000 year old trees near the volcano.

defrost 11mo ago
How about 12,000 years of overlapping ring patterns from paleo trees? Live trees, dead trees in buildings, bogs, tidal zones, etc. There's also sedimentation layers from multiple scattered bore samples that will reveal more about patterns of particle fall from the skies and layered flows from years past.
- sfn42 11mo ago
  I specifically meant live trees, didn't really occur to me that dead trees could be relevant. Not sure how common it is to find 12000 year old dead trees either but I guess it's more common than live ones. And of course geological surveys would definitely tell you something about the past
  - defrost 11mo ago
    Oak and other trees, felled several thousand years ago and used as trackway posts, in buildings, etc are the bread and butter of * https://en.wikipedia.org/wiki/Dendroarchaeology https://en.wikipedia.org/wiki/Dendroarchaeology Art historians often look at the wood panels of paintings that are 400 years or more old. You might enjoy reading the general overview: https://en.wikipedia.org/wiki/Dendrochronology https://en.wikipedia.org/wiki/Dendrochronology and, ahh, drilling deeper into the onion rings. The real problem with tree rings here in this specific case is ... Ethiopia .. not a lot of big trees now, nor in the recent past when it was grasslands - but not really my field - there's likely to be very slow growing unassuming trees that are surprisingly old there .. and remains of older trees that have overlapping ring sequences. But yes - geological / geophysical clues are likely more relevant here.
- bit1993 11mo ago
  Literally reverse engineering.
- SideburnsOfDoom 11mo ago
  > How about 12,000 years of overlapping ring patterns from paleo trees? Near this specific volcano? In a dry, "sparsely vegetated" region (1). Not a chance. https://en.wikipedia.org/wiki/Afar_Region#Land_features https://en.wikipedia.org/wiki/Afar_Region#Land_features
  - defrost 11mo ago
    Thank you for your thoughts. I addressed this an hour or so prior to your comment here: https://news.ycombinator.com/item?id=46146345 https://news.ycombinator.com/item?id=46146345 and would point out that Ethiopa (which I've visited, along with many other countries as part of my work in geophysical surveying) is famous for its Acacia trees: https://www.alamy.com/typical-ethiopian-landscape-with-acacia-trees-image353085193.html https://www.alamy.com/typical-ethiopian-landscape-with-acaci... This particular fact somewhat undercuts your strong assertion: > Not a chance. as there are actual well documented trees in the region that do form annual rings. The Afar isn't solely vegetated by Dracaena ombet which lack annual rings. https://en.wikipedia.org/wiki/Dracaena_ombet https://en.wikipedia.org/wiki/Dracaena_ombet
    - SideburnsOfDoom 11mo ago
      > This particular fact somewhat undercuts your strong assertion: My strong assertion, was not "there are no trees". Of course there are some trees of some size in some places. Not the same as an oak forest, but still. My strong assertion was regarding how very unlikely "12,000 years of overlapping ring patterns" would be from the sparser and smaller and less long-lived vegetation.
      - defrost 11mo ago
        You might want to look deeper into the links I provided re: dendrochronology. There's no necessity for 12K years of volcano adjacent tree ring sources, any more than there's a requirement that the current immediate vicinity have many trees. I can leave that for you to ponder, it's not hard to fathom why. The scope of volcano eruption also comes into play, of course, there's a bunch of papers about tree rings and evidence of volcanic eruption wrt: The Black Death (1347 - 1353) in Europe with a wide separation between volcano and tree ring sites. On a tangential note, of all the trees in all the arid places about the globe, these are some of my favourites: https://www.snexplores.org/article/carvings-australia-boab-trees-lost-history-first-nation https://www.snexplores.org/article/carvings-australia-boab-t... and https://theconversation.com/the-boab-trees-of-the-remote-tanami-desert-are-carved-with-centuries-of-indigenous-history-and-theyre-under-threat-191676 https://theconversation.com/the-boab-trees-of-the-remote-tan.... The Tanami's tough country, it's where the last people (known) to first encounter "western" civilisation walked out from. It's where several of them returned after a few years of exposure.( https://www.bbc.com/news/magazine-30500591 https://www.bbc.com/news/magazine-30500591 ) Do you have any stories of your time in the Ethiopian Afar that provide first hand field experience for your strong assertion? Getachew Eshete and Göran Ståhl did some work there in 1999 in the Rift Valley part of the Afar region that indicated Acacia growth rings can be used as climate indicators for the 30 year life span periods of the wood studied.
SideburnsOfDoom 11mo ago
I doubt there are any trees near the volcano, full stop. Do the basics: go to google maps, find the "Hayli Gubbi volcano", click for the satellite image. Not a forested area at all. I can see some light greenery near Lake Bakili. But not much. "The Afar Region as a whole is sparsely vegetated" - https://en.wikipedia.org/wiki/Afar_Region#Land_features https://en.wikipedia.org/wiki/Afar_Region#Land_features

SideburnsOfDoom 11mo ago

What trees? Near this specific volcano, not in a forest but in a dry, "sparsely vegetated" region (1). I don't expect any substantial trees at all. Google maps has the satellite imagery, it's pretty rocky and barren. https://en.wikipedia.org/wiki/Afar_Region#Land_features https://en.wikipedia.org/wiki/Afar_Region#Land_features