 Welcome to Geosciences 10. I'm Richard Alley and I'll be your tour guide to the geology of the national parks. In the course of the semester we're going to visit some of the most beautiful and interesting places in the world. We're going to ask some big questions. Why are there mountains and volcanoes and earthquakes? Why are the mountains torn down by rivers by glaciers? What's the history of this planet? How do we live on the planet? How do we stay happy and healthy and terrific with the planet? And while we're doing it we are going to visit some of the most beautiful wonderful places on the planet. At the end of the semester we're all going to know a lot more about the national parks and you're going to be so excited that next summer you're going to be off to visit one because they're such wonderful places. Have a great semester. I'm going to jump on my bicycle and head into school and get to it.