GEOS 212 1st Edition Lecture 1Outline of Last LectureN/A Outline of Current Lecture 1. Course logistics IntroductionsCourse web page: (link from D2L)Course organization and grading policyExtra credit opportunities2. Ocean BasinsBasics of oceans, solid earth, and atmospherePresent-day ocean basin characteristicsOcean basins thru geologic time plate tectonicsPlate tectonics on a short time scaleGeologic Time Current LectureThe surface if our globe is 70% ocean. Most oceans are roughly 3 miles deep (5km) with the exception of continental shelves (area submerged in water around continent). This means that all that volume of ocean is available for life (though a lot is found in continental shelves)! As a result of all this area available for life, 99% of all livable earth space is found in the ocean. *Compare all the volume of the ocean to the mere few hundred meters above and below land that is inhabited by life.Know this figure:In particular know that the Atenoshpere (red) is NOT molten. It is weak and it flows allowing tectonic plates (which are very strong) to slide of it. Think of slippery silly puddy!These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Subduction zone: collision between two of Earth's tectonic plates, where one plate sinks into the mantle underneath the other plate.Text accompanying subduction animation: Tsunamis are caused when one plate subducts and the adjacent plate starts to get pulled under with it by the frictional forces holding them together. Eventually, the tension is too great and the second plate overcomes the friction, snaps upwards, and pushes the whole column of water in that portion of the ocean straight up! That's a column of water roughly 600 miles deep (very heavy!). The water then "runs away" on the ocean's surface in a wave traveling at 500miles/hr (very
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