Geosystems Terms, Oceanography – Flashcards
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El Nino
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An irregularly occurring and complex series of climatic changes affecting the equatorial Pacific region and beyond every few years, characterized by the appearance of unusually warm, nutrient-poor water off northern Peru and Ecuador, typically in late December.
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Estuary
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Region where the sea and a river meet; usually protected area of brackish waterl essential to life in the ocean as these regions are used as spawning grounds.
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Oceanography
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The scientific study of the sea.
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Salinity
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Measure of disolved salts in water.
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Sedimentation
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deposit: the phenomenon of sediment or gravel accumulating
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Thermocline
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A transitional layer between the mixed layer of the surface and the deep water layer.
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Abyssal Plain
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Flat seafloor area at a depth of 10,000-20,000 ft (3,000-6,000 m), generally adjacent to a continent
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Continental Shelf
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the area of seabed around a large landmass where the sea is relatively shallow compared with the open ocean.
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Continental Margin
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the offshore zone, consisting of the continental shelf, slope, and rise, that separates the dry-land portion of a continent from the deep ocean floor.
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Continental Slope
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seaward border of the continental shelf. The world's combined continental slope has a total length of approximately 300,000 km (200,000 miles) and descends at an average angle in excess of 4° from the shelf break at the edge of the continental shelf to the beginning of the ocean basins at depths of 100 to 3,200 metres (330 to 10,500 feet).
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Continental Rise
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wide, gentle incline from an ocean bottom to a continental slope.
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Ridge
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Any section of the narrow, largely continuous range of submarine mountains that extends into all the major oceans and at which new oceanic lithosphere is created by the rise of magma from the earth's interior.
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Seamount
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An undersea mountain.
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Trench
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a long narrow steep-sided depression in the earth's oceanic crust, usually lying above a subduction zone
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Surface Current
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Horizontal motion of the upper 1000 meters of the sea; primatily driven by global wind patterns.
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Thermohaline Current
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Motion of the sea driven by density (temperature and salinity); causes deep currents which connect the global conveyor belt.
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Tidal Range
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The difference between high and low tide- varies by moon phase and bay shape, amongst other reasons.
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Tides
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Periodic rise and fall of the ocean surface due to the gravitational pull of the moon and sun.
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Upwelling
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Vertical movement of deep ocean water, cold and nutrient rich, toward the surface; due to either surface divergence or bathymetry, usually; creates regions of high productivity at the surface.
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Glacier
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a slowly moving mass or river of ice formed by the accumulation and compaction of snow on mountains or near the poles.
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Ice Age
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A glacial period in which the entire earth freezes over.
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Ice Cap
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A covering of ice over a large area for instance the polar regions of our planet.
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Longshore Current
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Water movement parallel to the shoreline; the reason you end up a mile down-beach from your towel when you swim in the ocean.
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Tsunami
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A moving wall of water caused by some sort of large scale under water disturbance such as underwater earthquake, landslide, or volcanic eruption, creating a full-column ripple effect in the ocean.
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Waves (ocean)
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A long body of water curled into an arched form. In actuallity it is actually energy pushing the water up around and back down right where it was before.
