APES | unit 4 vocab

• a horizon


  Frequently the top layer of soil, a zone of organic material and minerals that have been mixed together. Also known as topsoil.
• albedo


  The percentage of incoming sunlight reflected from a surface.
• b horizon


  A soil horizon composed primarily of mineral material with very little organic matter.
• c horizon


  The least-weathered soil horizon, which always occurs beneath the B horizon and is similar to the parent material.
• convergent plate boundary


  An area where plates move toward one another and collide.
• divergent plate boundary


  An area beneath the ocean where tectonic plates move away from each other.
• el nino southern oscillation


  A reversal of wind and water currents in the South Pacific.
• erosion


  The physical removal of rock fragments from a landscape or ecosystem.
• humus


  The most fully decomposed organic matter in the lowest section of the O horizon.
• o horizon


  The organic horizon at the surface of many soils, composed of organic detritus in various stages of decomposition.
• physical weathering


  The mechanical breakdown of rocks and minerals.
• rain shadow


  A region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean causing precipitation on the windward side.
• stratosphere


  The layer of the atmosphere above the troposphere, extending roughly 16 to 50 km (10–31 miles) above the surface of Earth.
• transform fault boundary


  An area where tectonic plates move sideways past each other.
• troposphere


  A layer of the atmosphere closest to the surface of Earth, extending up to approximately 16 km (10 miles).
• upwelling


  The upward movement of ocean water toward the surface as a result of diverging currents.
• watershed


  All land in a given landscape that drains into a particular stream, river, lake, or wetland.
• coriolis effect


  The deflection of an object’s path due to the rotation of Earth.