George Kvoner, age 11, of Brookfield, Ohio, for his question:

What does diastrophism mean?

A diastrophe is a deformed area of the earth's crust. The word diastrophism suggests action, some sort of operating system of action. This is correct. Dias¬trophism happens to be the mammoth granddaddy of all the earth's dramatic activities. It is a planet wide system of crustal upheavals that has operated since the earth began and is likely to continue until the end of earthly time. However, the mammoth operation usually is a gentle giant. Most of its massive motions happen too slowly to disrupt the short lived populations that inhabit the seas and surface of the earth.

Earth scientists use the term diastrophism to cover any and all of the large scale changes in the earth's crust. These changes may heave up mountains, sever and deform immense crustal slabs to form faults and volcanoes. They may model and remodel continents and ocean basins. These immense operations are triggered by forces within the crust, by deeper forces below it and to some extent, by weathering activities on the surface. The interaction of global forces is immense and earth scientists still are probing to explain all the details of diastrophism.