Making Skeleton Plots

When skeleton plotting ring-width variation of a core, note that: Narrow rings merit marks on the skeleton plot The narrower the ring, the longer the mark Very wide rings occasionally merit a little "b" mark (for big) Normal or average rings DO NOT merit marks on the skeleton plot For example, compare the core and skeleton plot below: The narrowest ring is connected (blue line) with the longest skeleton mark The widest ring is connected (green line) with a "b" mark (for big) Note the red line: Points to a ring of average width, but it seems narrow compared to the preceding ring Perhaps it merits a small mark because of the large year-to-year difference Good idea: Hit the "Try Again" button to see more examples

How to make marks when you try skeleton plotting for yourself:
	You'll see a panel of circle options, as on the left: You can either draw or erase marks with your mouse Marks may be either: normal lines for narrow rings a "b" for wide rings a mark for the ring-growth anomalies of absent or false rings Practice making normal marks on the right: Align tip of cursor on vertical line of choice Adjust height of cursor in bottom two-thirds of graph Mouse click just once! "Try Again" as necessary If you mark something mistakenly: Just mouse click on the "Erase" circle option Put mouse over the mistake and click it away Don't forget to mouse click back onto "Draw" to continue plotting

Copyright © 1999-2002 Laboratory of Tree-Ring Research, The University of Arizona
Revised – March, 2002
URL: http://tree.ltrr.arizona.edu/skeletonplot/plotting.htm