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Title: Global Change: Logs of Straw; Dendrochronology

Journal Article · · California Geology
OSTI ID:273998

The U.S. Geological Survey has produced a teacher`s packet targeted for grades 4 through 6 entitled Global Change. Each Global Change packet contains the following inserts: (1) A color poster depicting the earth as a fragile planet on one side, and examples of visible global change on the reverse. (2) Three activities addressing {open_quotes}Time and Cycles,{close_quotes} {open_quotes}Change and Cycles,{close_quotes} and {open_quotes}Earth as Home{close_quotes} (3) A teacher guide (4) An evaluation questionnaire. Trees are some of nature`s most accurate time-keepers. Their growth layers, appearing as rings in the cross section of the tree trunk, record evidence of floods, droughts, insect attacks, lightning strikes, and even earthquakes. Tree growth depends on local conditions, which include the availability of water. Because the water cycle, or hydrologic cycle, is uneven-that is, the amount of water in the environment varies from year to year-scientist use tree-ring patterns to reconstruct regional patterns of drought and climatic change. This field of study, known as dendrochronology, was begun in the early 1900s by an American astronomer named Andrew Ellicott Douglass.

OSTI ID:
273998
Journal Information:
California Geology, Vol. 47, Issue 5; Other Information: PBD: Sep-Oct 1994
Country of Publication:
United States
Language:
English