Have you ever looked down on the Utah valley from the Y, or the mountains where you live? Have you ever wondered how the valley was formed? Well...here are some interesting facts to ponder: 1. Where would the big earthquake happen in Utah? During the past 6,000 years, large earthquakes have occurred on the Wasatch fault on the average of once every 400 years, somewhere along the fault’s central active portion between Brigham City and Levan. 2. What would happen if a magnitude 7.5 earthquake shook the Wasatch fault? Strong ground shaking could produce considerable damage up to nearly 50 miles from the earthquake. The strong ground shaking may be increased by factors up to 10 or more on valley fill compared to hard rock. (A house built on a rock will do better than a house built on sand and gravel). Also possible are soil liquefaction, landslides, rock falls, and broad permanent tilting of valley floors possibly causing the Great Salt Lake or Utah Lake to overflow into parts of Salt Lake City or Provo. Closeup of the fault surface breaking through sediments along the Wasatch Mountain Range front, Utah. Notice how the fault breaks through near the bottom of one of the eroded, triangular-shaped slopes that mark the surface of the range-front fault. The above photo shows the fault (or crack) where the valley dropped. 3. How often do we feel earthquakes in Utah? About 700 earthquakes (including aftershocks) are located in the Utah region each year. Approximately 2% of the earthquakes are felt. An average of about 13 earthquakes of magnitude 3.0 or larger occur in the region every year. Earthquakes can occur anywhere in the state of Utah. 4. Is the Wasatch fault the same as the San Andreas fault in California? No. The San Andreas fault slips horizontally with little vertical movement. This is called a strike-slip fault. The Wasatch fault slips in a primarily vertical direction, with the mountains rising relative to the valley floor. The Wasatch fault is a so-called normal fault. Guess what? You get to learn this stuff next year!! How lucky is that? If I were you, I could hardly wait!
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Mrs. TaylorI love science! Everything about the world is interesting and never boring. I love to study plants, animals, insects, and people. My favorite subjects are my students who are the most unique organisms on the planet! Categories |