#rockinreview  #platetectonics

*Who is Alfred Wegener? Describe what he is known for and what it is.

         Alfred Lothar Wegener was a German polar researcher, geophysicist and meteorologist. During his lifetime he was primarily known for his achievements in meteorology and as a pioneer of polar research, but today he is most remembered for advancing the theory of continental drift in 1912, which hypothesized that the continents were slowly drifting around the Earth.

Meteorology- weather science.

*Define convergent, divergent and transform boundaries.

             In plate tectonics, a convergent boundary, also known as a destructive plate boundary (because of subduction), is an actively deforming region where two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide.

             In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or anextensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other.

             A transform fault or transform boundary, also known as conservative plate boundary since these faults neither create nor destroy lithosphere, is a type of fault whose relative motion is predominantly horizontal in either sinistral or dextral direction.

*Find a picture example that shows each boundary type.

*What tectonic plate is just off the coast of Washington?

           The Juan de Fuca Plate

*What role does that tectonic plate have on the formation of the Cascades? Be very specific how it affects the Cascades. The more detail, the better.

            The Cascade Volcanoes were formed by the subduction of the Juan de Fuca, Explorer and the Gorda Plate (remnants of the much larger Farallon Plate) under the North American Plate along the Cascadia subduction zone.

*Describe convection currents and the role they play in plate tectonics.

            Large convection currents in the aesthenosphere transfer heat to the surface, where plumes of less dense magma break apart the plates at the spreading centers, creating divergent plate boundaries.

As the plates move away from the spreading centers, they cool, and the higher density basalt rocks that make up ocean crust get consumed at the ocean trenches/subduction zones. The crust is recycled back into the aesthenosphere.

*Define rift zone

            A rift zone is a feature of some volcanoes, especially shield volcanoes, in which a linear series of fissures in the volcanic edifice allows lava to be erupted from the volcano's flank instead of from its summit.

*Define subduction zone

            In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate and sinks into the mantle as the plates converge.

*Find out how the "Channeled Scablands" were formed. Be very detailed in your answer! You are living in them!

              The Channeled Scablands are a barren, relatively soil-free landscape in eastern Washington, scoured clean by a flood unleashed when a large glacial lake drained.[1] They are a geologically unique erosional feature in the U.S. state of Washington. They were created by the cataclysmic Missoula Floods that swept periodically across eastern Washington and down the Columbia River Plateau during the Pleistocene epoch.