Earth Sciences 1023A/B Lecture 15: Earth Sci Plate Boundaries
18 Apr 2019
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Document Summary
Earth"s surface is divided into rigid lithospheric plates. Ocean lithosphere is destroyed at deep sea trenches (subduction zone) The processes explain the global distribution of earthquakes and volcanoes. Consists of the outer part of the earth. Large plates (north american, south american, eurasian, african, australian, antarctic, Small plates (arabian, indian, scotia, carribbean, nazca, cocos, juan de fuca, In support of hess" sea oor spreading model (mantle convection) Proposed transform plate boundary to explain linear fracture zones in oceans. Transform faults= compensate for earth"s curvature > plates move past one another (at fracture zones) Describe action of material after the rise has been offset. Can only be associated with mid ocean ridges. Offset segments of spreading ridges in sea oor. Originate from the core-mantle boundary (2900km below the surface of the earth) Hawaiian islands were formed by a single hotspot. Another island is being formed (seamount) called luihi.
