UNIT 2 Set

  • Core: The innermost, dense sphere of the Earth, composed of iron and nickel.

  • Mantle: The layer between the core and the crust, composed of hot, semi-solid, molten rock capable of slow movement.

  • Crust: The outermost layer of the Earth, a solid rock shell.

  • Lithosphere: The rigid outer part of the Earth, consisting of the crust and upper solid mantle.

  • Asthenosphere: The upper layer of the Earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

  • Tectonic Plates: Large sections of the Earth's lithosphere that float on the asthenosphere.

  • Plate Tectonics: The theory that the Earth's lithosphere is divided into tectonic plates that move relative to each other.

  • Seafloor Spreading: The process by which new oceanic crust is formed through volcanic activity at mid-ocean ridges and then moves away from the ridge.

  • Paleomagnetic Striping: Alternating bands of normal and reversed magnetic polarity in rocks on either side of a mid-ocean ridge, indicating reversals in Earth's magnetic field over time.

  • Convergent Boundary: A plate boundary where two tectonic plates move towards each other.

  • Subduction Zone: An area where one tectonic plate slides beneath another.

  • Divergent Boundary: A plate boundary where two tectonic plates move away from each other.

  • Mid-Ocean Ridge: An underwater mountain range formed by plate tectonics, typically at a divergent boundary.

  • Hydrothermal Vent: An opening in the seabed where superheated water, rich in dissolved minerals, is released.

  • Transform Boundary: A plate boundary where two tectonic plates slide past each other horizontally.

  • Weathering: The gradual breakdown of rocks and minerals into smaller pieces.

  • Erosion: The process by which weathered material is transported from one place to another.

  • Sedimentation: The deposition of suspended particles (sediments) in a new location.

  • Littoral Zone: The area along a shoreline that is affected by tides and waves; the intertidal zone.

  • Tides: The periodic rise and fall of the surface of large bodies of water, caused by the gravitational pull of the Moon and Sun.

  • Spring Tide: A tide with the greatest difference between high and low water, occurring during a new or full moon when the Earth, Moon, and Sun are aligned.

  • Neap Tide: A tide with the least difference between high and low water, occurring during the first and third quarter moons when the Earth, Moon, and Sun are at right angles.

  • Ocean Currents: Continuous, directed movement of seawater.

  • Thermohaline Circulation: Deep ocean currents driven by differences in temperature and salinity.

  • Upwelling: The upward movement of cold, nutrient-rich water from the deep ocean to the surface.

  • Downwelling: The downward movement of surface water into the deeper ocean.

  • Coriolis Effect: An apparent deflection of moving objects (like air and water) caused by the Earth's rotation.

  • El Niño: The warm phase of the El Niño Southern Oscillation (ENSO), characterized by warmer than average sea surface temperatures in the central and eastern tropical Pacific Ocean.

  • La Niña: The cool phase of the El Niño Southern Oscillation (ENSO), characterized by cooler than average sea surface temperatures in the central and eastern tropical Pacific Ocean.

  • ENSO (El Niño Southern Oscillation): A climate pattern that occurs across the tropical Pacific Ocean, characterized by fluctuating ocean temperatures and atmospheric pressure.