Purpose: How do we use dendrochronology?

Warmup: Finish each item

Meteorologists discover ancient climate conditions by many ways:

1) Glaciers shrinking tells us…2) Sakura occuring late tells us…3) Analyzing ice layers tells us…4) Thin tree rings tell us…

5) .6) .

Dendrochronology is the dating and study of annual rings in trees.The word comes from these roots:ology = the study ofchronos = time; more specifically, events

and processes in the pastdendros = using trees; more specifically,

the growth rings of trees

Climate is the amount of ______ and ______ measured over a LONG period of time.Tree ring thickness tells us old climate information, both the ______ and the _______ of old years.

Tree rings are striped because…

A single tree ring

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Tree rings are striped because…

Three completely different ways to look at this set of rings…

This picture of a conifer wood sample shows . The rings display much variation:

A fire scarred spruce tree

Narrow rings mean…They occur in…

http://www.yukonenvirothon.com/dendrochronology.html

Buried by a glacier circa 1120 AD

http://www.flickr.com/photos/98204544@N05/9241618498

Rings of trees show insect outbreaks

What Tree-Ring Reconstruction Tells Us about Conifer Defoliator OutbreaksAnn M. Lynch

Environ. Res. Lett. 6 (October-December 2011) 045503doi:10.1088/1748-9326/6/4/045503Varying boreal forest response to Arctic environmental change at the Firth River, AlaskaLaia Andreu-Hayles1,2, Rosanne D'Arrigo1, Kevin J Anchukaitis1, Pieter S A Beck3, David Frank4,5 and Scott Goetz3

http://iopscience.iop.org/1748-9326/6/4/045503/fulltext/

http://www.cpat.org.uk/educate/leaflets/archaeol/archaeol.htm

http://www.wageningenur.nl/en/Expertise-Services/Chair-groups/Environmental-Sciences/Forest-Ecology-and-Forest-Management-Group/DendroLab/Research/Dating-Dendroprovenancing.htm

False Bands/Rings

. trees, ice core, pollen, sediment ocean, season onset from sakura and lake ice, food, images, oxygen isotopes

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Locally Absent Rings

Locally Absent RingsTop part of this photo has 3 full rings.Lower part of this photo has 4 full rings.The wedge that is the 4th ring is "locally absent" from part of this tree.This sample is dateable, but NOT by mere ring counting.

I’m Melting!

Global WarmingCorrelation Between CO2 and

Temperature

13. Making a Clinometer      15 PointsIf you want to know how tall a chair or your desk at school is, you can take a meter stick and measure it. But what if you want to know the height of something really tall like a tree in your schoolyard? Can you think of a way to measure the height of tall things?Here is a method that uses the geometry of right-angled triangle to measure the height of tall objects.•Follow the directions and construct a clinometer.•Use the clinometer to measure the height of 10 trees.Making a Clinometer found at: http://educ.queensu.ca/~fmc/march2004/tree5_01.html  14. Reading the Rings      5 PointsTo help figure out what climate the tree grew in and what the environment was like, look at each ring:•ThicknessHow wide a ring is can tell you if the environment was good or bad for the tree to grow in. In years when the amount of rain and temperature were good a tree's rings are wider. In bad years a tree's rings are thinner. •ShapeIf rings become thinner on one side than the other it means the tree is leaning over to one side. High winds or a big storm can cause a tree to lean. •Strange MarksDr. Fir also looks for strange marks, like scars, and other "pieces of evidence." Scars can be left by insects or disease. A forest fire can leave burnt marks.•Describe dendrochronology. What is it? How is it done? How is it used to calibrate the C-14 Radioisotopes dating method? Illustrate with a picture.

It is _____________________________________________________It is done by ______________________________________________________________________________________________________________________________________________________________It is used to calibrate the C-14 radioisotopes dating method by ______________________________________________________________________________________________________________________

Illustration of dendrochronology

How Old is Old?1. What are the two types of dating used by archaeologists?

1.Relative2.Absolute

10. What is dendrochronology?

Dendrochronology is a scientific dating method using the rings in trees.11. Describe how “dendrochronology” is used by archaeologists.

Rings change according to climate—scientists match similar rings on artifacts and trees with known ages. It works just like grocery store scanners.12. What are some advantages and disadvantages of using tree ring dating?Advantages: very accurate—gives exact dateDisadvantages: only good for a few thousand years and only in certain places

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