#dendrochronology

[mindblowingscience]

Bryan Black, an associate professor of dendrochronology at the University of Arizona Laboratory of Tree-Ring Research, has been applying the tree-ring dating techniques to so-called “fish rings” to understand how environmental variability is affecting fish growth and productivity over decades.

Continue Reading.

[mixotrophics]

time layers

tree rings tree-time / dendrochronology. Look at a cut log, look at its rings. growth in trees occurs near the bark, while the deeper-in core layers are preserved rings of past growth.

The seasons / environment affect the growth rate of the tree , creating generally a visual difference between spring / summer+autumn ring growth in temperate regions, hence 1 ring = 1 seasonal cycle. Generally, spring is associated with less-dense, rapid growth, while summer (sometimes into autumn) growth is denser.

width of rings can also be used more finely, wider rings = more growth that year, so probably better conditions... overlapping ring-dates between trees can lead to a long, multi-tree chronology for the area.

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ice cores layers are built by annual snow, compacted into ice underneath the layers forming above. Ice traps atmosphere , how we can know the rough % oxygen/carbon dioxide/etc of past atmosphere circumstances. Heat doesn't flow well through ice, so even past temperatures can be trapped in large sheets.

dust and marine salt-ions can be trapped within, giving further depth to past ecologies.

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lake cores mud at the bottom of the lake builds up in undisturbed layers, trapping things that land in the lake and sink.

Trapped pollen can be observed under a microscope & can identify what plant it is from, helping the understanding of how plants spread ; such techniques have been used to find out when some crops were domesticated & cultivated (1).

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sedimentary & metamorphic rocks an iconic time-layering. sediment builds up in layers, compresses under the weight of the layers above and becomes stone. Traps things in there, and they may become coal, fossils, etc. Other things are trapped: the ripples in sediment formed by waves, so that we may know past sand-beaches.

with enough time, these layers become distorted by geological processes, becoming Wiggly (should they move downwards), getting turned non-horizontal, getting weathered (should they be exposed to air/water/etc), so on.

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scutes scutes: plates of a tortoise/turtle's carapace. They grow more quickly in warm seasons than cold ones, forming a ring much like a tree's, even mirroring that same seasonality. elderly animals may have worn-down scutes so particularly-old animals are difficult to age exactly (2).

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otoliths inner-ear-bones. in fish, the large otoliths also form rings with age, so fish-ages can be counted. Again, they are seasonal, growing faster in the summer and slower in the winter.

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stromatolites bacterial fossils / fortresses. on the sea-floor, bacteria can grow into a mat, which is sticky... sand and such gets stuck, forming a layer, and the bacteria then migrates to the top of that layer. repeat. sometimes, more than sediment is stuck : microfossils, for example (3).

stromatolites used to be commonplace, but they do not form without enough of a bacterial mat: in modern times, the mat struggles to form under grazing pressure from things such as snails, shrimp, and so on. Modern stromatolites -- their mats formed of different bacteria than the ancient ones -- can be found in places too harsh for their predators to inhabit.

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baleen whale baleen, the filter-teeth they have, grows in a sturdy sheet. The filter-bristles are formed by the rubbing of baleen-on-baleen, breaking the sheet's ends apart. To compensate for continual wear, the baleen grows.

hormones, which can indicate stress, pregnancy, etc , and isotopes, which indicate different water conditions and therefore different locations / food, are stored in the baleen (4). while the growth/wearing means it is not a complete record of a whale's life, it is still an invaluable and rich slice.

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sources:

Åkesson, C. M., McMichael, C. N. H., Bush, M. B., Late-Holocene maize cultivation, fire, and forest change at Lake Ayauch, Amazonian Ecuador, Sage Journal

Attenborough, D., Life in Cold Blood

Microbal Mats

Holland, J. S., A whale's baleen bristles reveal the story of its life, Smithsonian Magazine

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if you know others, feel free to add :]

[the-cricket-chirps]

Bryan Nash Gill

Red Ash

2007

(© Bryan Nash Gill)

[lindahall]

Andrew E. Douglass – Scientist of the Day

Andrew Ellicott Douglass, an American astronomer, was born July 5, 1867.

Learn more

[spatheandspadix]

Thick Trunk Tuesday: me and a very large oak stump at Ridley Creek, pointing out how much it grew in its last 36 years

[eddie-roo]

Visual Inspiration

Stemian Natu

The stump Pokemon

STEM topic: Dendrochronology

The Natu of Stema have been found to make psych connections to trees dead and alive.

It is said that if you look through a Natu’s perforation while it sleeps on a stump you’ll be able to get a glimpse of the past.

Stemian Xatu

The orbital Pokémon

STEM topic: Carbon 14 dating

Unlike the Xatu of Johto, Stemian Xatu can look far into the past instead of predicting the future, some speculate they actually experience time in reverse.

When the sun shines through Xatu’s perforation a projection of a past event will play for a brief moment, this has made them an invaluable companion for Stemian historians.

Uatu

The crystalline Pokémon

STEM topic: U-Pb dating, isotope decay

Almost like a living computer, Uatu have one of the most complex brains amongst Pokémon, being able to effortlessly make lengthy calculations in the blink of an eye or three.

Uatu are reclusive beings, almost never interacting with other creatures be it Pokémon or human making them quite difficult to train. It is said that when a Uatu has found a trustworthy partner, it’ll share some of its vast knowledge with them as a sign of respect.

Layout inspired (cough cough, copied, cough cough) from @n0rtist, because it is his challenge and I wanted it to look on brand.

[wtfearth123]

Tree rings reveal the secrets of the past and the present. They can show us the age of a tree, the climate conditions it experienced, and even the history of human civilizations that used its wood.

[ancientstuff]

Dendrochronology - reading tree rings. Interesting source for ancient climate study.

[thepastisalreadywritten]

[ahb-writes]

[jayther]

Dendrochronology

Subtext: "These anomalies are known as Miyake events, named for the pioneering scientist who discovered them and was tragically devoured by a carnivorous tree."

[informativesisters]

How to determine the age of a tree by counting its rings #shorts #ytshorts

[amanonthecorner]

Who figured out you can count in the rings in a tree to find out how old they were? Who was out there counting how old trees were and checking the results?

[the-cricket-chirps]

Bryan Nash Gill

Honey Locust

2010

(© Bryan Nash Gill)

[anglerflsh]

>"write about the contribuition of a female archeologist" >picks out someone from the 30s whose internet presence is almost nonexistant except for a few articles all in russian with a 2005 kind of website graphic that I then have to painstakingly translate in order to understand, and whose work revolves around a tecnique of dating that preceeded carbon-dating and that isn't even used at all anymore >you can't even find her most popular book in english at all. There is one anglophone article on one random journal that even mentions her.