EESA06H3 Chapter 2: Chapter 2 (beginning)
Document Summary
Tectonics is the study of the origin and arrangement of the broad structural features of earth"s surface. Plate tectonics: earth"s surface divided into a few large, thick plates that move slowly and change in size. Intense geologic activity occurs at plate boundaries. Where plates move away from one another, past one another, or toward one another. Continents move freely over the earth"s surface, changing their positions relative to one another. Sea floor forms at the crest of mid-oceanic ridges, then moves horizontally away from the ridge crest toward an oceanic trench. Two sides of ridge move in opposite directions like conveyor belts. Wegener proposed that continents ploughed through the oceanic crust, perhaps crumpling up mountain ranges on the leading edges of the continents where they pushed against the sea floor. Sidescan sonar: measures the intensity of sound reflected from the ocean floor and provides detailed images and information about sediments and bedforms on the sea floor.
