EESA06H3 Lecture Notes - Lecture 4: Plate Tectonics, Seismic Gap, Triple Junction
Document Summary
Eesa06h3: lecture 4: how oceans form: the east african rift. Key words, terms and concepts: uniformitarianism: looking at modern examples and then looking at rocks that are billions of years old. Toronto, new york and other places are built on ancient failed rifts: those failed rifts are still moving and creating earthquakes. (cid:858)aa(cid:859) and (cid:858)pahoehoe(cid:859) lavas, cascading ea(cid:396)th(cid:395)uakes(cid:859, seismic gaps. Fig 2. 38 in textbook: the plume is coming out of the outer core, it reacts with the bottom of the plate, then uplifts the plate, then a hot spot volcano forms. But the plate is always moving: thus, plate movement carries the volcano away. The volcano dies because it is removed from its source of magma: seamount: a little bump on the oceans floor, but its growing. An underwater mountain formed from volcanic activity: as the rock cools, the density increases, the rocks get heavier. The rocks want to sink: guyot: are flat topped seamounts.
