complete attached answer sheet
Unit 12 Lab Exercise: Weathering and Mass Wasting Instruction and Answer Sheet You need to open in Google Earth the Unit12_Weathering_karst.kmz for this exercise. Exploration 1: Weathering Double click on the Weathering placemark and make sure that its box is checked. This series of placemarks will introduce you to weathering processes. 1. Half Dome is an excellent example of the rounded domes produced by pressure-release jointing and exfoliation. There are at least four more similar domes within five miles of Half Dome. Explore the national park and watch out for domes. Have you ever wondered why there’s only half of the dome? It was a work by Glaciers. Notice the wide valley by the half dome? That was the pathway of glaciers. How wide is the main valley?(Answer in space below) Now go to Grand Canyon National Park and adjust your view angle, zoom level, and perspective to be able to measure the width of the canyon bottom. How wide is it? (Answer in space below) The valley created by glaciers are U-shaped valleys that are often much wider than those V-shaped valleys created by rivers. 2. Double click on the Mt. Whitney and the Alabama Hills placemark. You will fly to the east side of the Sierra Nevadas. In the foreground are the Alabama Hills, on the horizon you can see the crest of Mt. Whitney, the highest point in the lower 48 states. Both the Alabama Hills and Mt. Whitney are made from the same granite, but they look quite different. Describe the differences in their appearances. (Answer in space below) You can learn more about the geologic processes and weathering forces that shaped the rugged mountain peaks including Mt. Whitney and Alabama Hills by reading this blog post: https://blogs.agu.org/mountainbeltway/2018/02/08/spectacular-display-earth-science-alabama-hills/ 3. Double click on the Mt. Whitney placemark and explore the mountain peaks and valleys around it. How wide is the valley to the west of Mt. Whitney (for example, the valley at 36.573N, 118.409W, adjust your view to a perspective view instead of birds-eye view to measure)? (Answer in space below) How wide is the valley downhill, say, at Whitney Portal (again, adjust your view to take a perspective viewing angle before you measure)? (Answer in space below) Recall from question 1, what accounts for the difference in the width of the valleys? (Answer in space below) 4. Double click on the Alabama Hills placemark. Explore the Alabama Hills region. Pay attention to the overall shape of the hills and their patterns. Do you see the presence of many joints (cracks)? What would this suggest about the weathering rates? (Answer in space below) 5. What are the specific weathering processes that might have been in operation to shape the Alabama Hills? (Answer in space below) Exploration 2: Karst Landscapes Double click on the Oolitic, IN placemark and make sure that its box is checked. This overlay is a topographic map overlay of the karst topography around Oolitic, Indiana. 6. How would you characterize the topography of the area with the high concentration of sinkholes? (You may have to turn up the elevation exaggeration to 3 times the original and use a perspective view in order to see it clearly: Google Earth Pro ->preferences->3D view). (Answer in space below) 7. Compare the lakes in the sinkholes on the map overlay with the Google Earth imagery. Does it look like the landscape has become wetter or drier since the map was made? (Answer in space below) 8. What economic activity do you notice around Patton Hill? What type of rock would be involved, given that this is a typical karst region? (Answer in space below) 9. Double click on the Arecibo, PR, placemark. What type of karst feature is the radio telescope in? This used to be the world’s largest radio telescope until 2016, when China built a larger one. Search “FAST telescope” on Google Earth’s search panel. Guess what type of landscape it is located on? Explore around, you will see quite a few similar features. (Answer in space below) Exploration 3: Mass Movement Double click on the Mass Movement placemark and make sure that its box is checked. This series will introduce you to some examples of the main types of mass movement. You will need to expand the folder to check each placemark on in turn to examine the individual placemarks. 10. The Gros Ventre mass movement event involved a Shale rock layer that lost its resistance to shear stress after it was moistened. Refer back to the lecture, what type of mass movement was this? (Answer in space below) You may read about this event here: https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5340454.pdf 11. Check and double click on the Chaos Jumbles placemark. The Chaos Jumbles and the Devastated Area were formed by the collapse of one of the plug domes of the Chaos Crags approximately 300 years ago. The resulting rockfall-avalanche trapped air, creating an air cushion avalanche. The mass of tumbling rock travelled at 160 kmh (100 mph) down the slope, across the plain, and up the side of Table Mountain. Measure the elevation from the lowest spot you can find on the slide surface up to the Toe of Slide placemark. The elevation of the ground under your cursor is shown at the bottom of your screen. How far did the slide travel horizontally? How far did it travel vertically up the slope of Table Mountain? (Answer in space below) 12. Check and double click on the La Conchita placemark. This is the site of two slides. The first was in 1995, and the second was in 2005. Click on the clock icon on the toolbar to show historical imagery. If you slide back to 2002 you can see the hillside before the 2005 slide, which killed 10 people. How many meters did the debris travel from the base of the hill shown in 2002 to the toe of the 2005 slide? (Answer in space below) 13. Zoom out to an altitude of 3 or 4 kilometers. What evidence do you see of other slides in this area? (Answer in space below)