Message-Id: <3.0.32.19970929085340.00701fc0@icefog.polarnet.com>
Date: Mon, 29 Sep 1997 08:53:47 -0800
To: geoffr@eastside.org
From: "J. Lahr" <jlahr@polarnet.com>
Subject: Plate Tectonics
Hello Ruth,
I think your pudding idea sounds good, but I haven't tried anything like
that. Sometimes plate tectonics is described as a soup with dumplings.
The dumplings are like the continents and always float on the top while the
soup comes up, cools, and goes back down. However soup doesn't form a crust
like pudding and magma does.
I've made a wooden model of plate tectonics with sliding ocean floor
represented by a plastic place mat. The place mat(s) emerge from a slot (an
ocean ridge), travel horizontally (creating strike-slip faulting motion),
and sink at a trench (subduction and thrust faulting). Volcanoes are
located above the zone where the plate is 100 km below the surface of the
earth (small bumps on the surface of the model.)
John Lahr
USGS Seismologist, Fairbanks, Alaska
>Date: 28 Sep 1997 11:27:59 U
>From: geoff ruth <geoffr@eastside.org>
>Subject: Plate tectonics
>Does anyone have any suggestions for good labs or in-class demonstrations
>to do about plate tectonics? I'm toying with the idea of demonstrating how
>the plates move by making pudding and letting a skin develop on the top,
>which I can them move around. But I'm not sure how well that would actually
>work in class. Any proven activities to make this cool idea more concrete?
>Geoff Ruth
>Eastside School
>2101 Pulgas Avenue
>East Palo Alto, CA 94303
>(650) 323-5898
-- * John C. and Jan H. Lahr * * jlahr@polarnet.com * * P.O. Box 83245, Fairbanks, AK 99708 * * (907) 474-7997 * * http://www2.polarnet.com/~jlahr * * http://giseis.alaska.edu/Input/lahr *