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Donjek Glacier in the Saint Elias Range, Yukon Territory, Canada. 1985. — Credit: Natural Resources Canada . Photograph by Douglas Hodgson. Copyright Terrain Sciences Division, Geological Survey of Canada.
See more pictures of natural disasters . When it comes to natural disasters, the tornadoes and tsunamis of the world tend to get all of the attention. Rarely do landslides seize as many headlines as the volcanoes and earthquakes that can cause them. But when the ground literally rips downhill, the effect is often more damaging than the trigger.
Click the play button to start the earthquake. When P and S waves reach the earth's surface, they form L waves. The most intense L waves radiate out from the epicenter. When you toss a pebble into a pond, it creates radiating waves in the water .
The three types of rocks—igneous, sedimentary, and metamorphic—are all subject to processes that change one rock type into another. The images below show several types of rocks undergoing these processes. Just as evaporation and precipitation are processes that move water through the water cycle, igneous, sedimentary, and metamorphic rock-forming processes move rocks through the rock cycle. In this investigation, you’ll examine a detailed example of a rock traveling through the rock cycle. <p style="text-align:right;color:#A8A8A8"></p>
You will be learning about the structure, history, and geologic principles that are the basis for the Geologic Time Chart. The Geologic Time Chart is one of the most important tools you will use as a Docent at the Idaho Museum of Natural History. Consequently, understanding the geologic principles and history of the chart will definitely be a great assistance to you as you work with groups of school children in the museum's galleries. So what is the Geologic Time Chart?