EESA06H3 Chapter Notes - Chapter 2: Bedform, Magnetite, Echo Sounding
Document Summary
Plate tectonic theory: suggests that surface of earth is divided into several large plates that change in position + size: intense geologic activity (volcanic eruptions, earthquakes) occur @ plate boundaries. Tectonics: the study of the origin/ arrangement of the broad structural features of the earth"s surface (mountain belts, continents, earthquake belts) Plate tectonics explains earthquake distribution, origins of mountain belts, origins of sea floor topography, distribution and composition of volcanos etc. Concept of plate tectonic was developed by combining ideas of continental drift and sea-floor spreading. Continental drift: idea that continents move freely over earth"s surface, changing its position relative to one another. Sea-floor spreading: hypothesis that sea floor forms at crest @ mid ocean ridges, then moves horizontally away from ridge crest towards an oceanic trench both sides of ridge move in opposite directions (like conveyor belt) 1990s: alfred wegener made a strong case for continental drift noted s. america, africa, india,
