Using optical and electron microscopes, scientists can detect how crystals within rocks change their sizes, shapes, and orientations when the rocks are subjected to heat and stress. These atomic-scale changes can ultimately lead to earthquakes and volcanoes. Large crystals are evident in a photo of “undeformed” rock from the Indian Ocean seafloor (top). But (bottom), the crystals are broken and ground up in similar rock subjected to stress. (Photo by Greg Hirth,Woods Hole Oceanographic Institution)[back]
|
