ENVIRSC 1G03 Lecture Notes - Lecture 15: Mid-Ocean Ridge, Longshore Drift, Abyssal Plain
2 Oct 2017
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Document Summary
15. 1 introduction: coast - region where land meets the sea. 15. 2 landscapes beneath the seaa: distinction between land and sea exists because continental and oceanic lithosphere differ markedly from one another by composition,, thickness. Indicate different bathymetric provinces distingushed by water depth. Submarine canyons - relatively narrow and deep valleys: downcut into continental shelves and slopes, some start off shore of major rivers and for good reason: rivers cut into continental shelf at times. Bathymetry of oceanic plate boundaries: mid ocean ridge -2km high submarine mountain belt, axis of ridge may be bordered by escrapments. Fracture zones can be traced into oceanic plate away from ridge axis where theya re not seismically active but still form boundary between plates of different ages: trench - deep elongate trough bordering a volcanic arc. Blanket consists mostly of plankton shells and fine flakes of clay. Seamounts - hot-spot volcano active or not , those that lie below sea level.
