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Unformatted text preview: Climatic Influences on Coasts Climatic I.. Composition of Beaches I Shell content Sand and Gravel glacial deposits Sand Sand rivers Sand Sand and Shells rivers and organisms Sand
(shells increase from North to South) CaCO3 coral and organisms Glaciated Coasts: contain sand and gravel deposits Mid-Atlantic: rivers delivered sand to the coast Florida: warmer water is more conducive to creatures living in the nearshore; Creatures have shells II. River Discharge Qs II. Northern Rivers bedload sand produced by physical weathering Southern Rivers suspended load mud due to chemical weathering III. Warm-Water Environments III. Coral Reefs: composed of CaCO3 Polyps: have a symbiotic relationship with Zooxanthellae (Blue-Green Algae) Hermatypic corals contain Zooxanthellae and are reef-producing Environmental Requirements Environme Substrate—something to grow on Warm Water—live in warm water Salt Water—34-35%0 Shallow Water—sunlight Non-Turbid Water—drown in mud Wave Action—food nutrients, reproduction, remove wastes B.. Oolite Shoals (CaCO3 sand) B Intense heat in Tropics produces extreme evaporation rates Concentrates Salt in water Calcium Carbonate is precipitated in concentric shells around a nucleus C. Mangroves Type of tree or large bush that grows in salt water Low energy conditions Much of the root structure is above water; Pneumataphores and Prop Roots Roots baffle currents causing sedimentation D. Beach Rock Part of a sandy beach that becomes rock Salt spray or storm waves wet upper beach sand with salt water High evaporation leads to CaCO3 cementing sand grains Common to arid, high temperature settings Beach Rock Beach Rock Formation Time 1: Storm waves/salt spray infiltrates upper beach, water evaporates, salts get left behind Time 2: Calcium Carbonate, CaCO3 cements sand grains Time 3: Beach rock IV. Barrier Formation in Arctic North slope of Alaska has unique horse-shoe shaped barriers They form due to ice processes During ice break-up, ice blocks are pushed onshore by the wind Ice blocks bull-doze sand from inner shelf onshore WIND ICE Sand and Gravel ICE PUSH ICE Sediment piled up by ice Wind Wind Represents Sun’s energy Due to pressure gradients Differential heating by Sun Global Atmospheric Circulation
Horse Latitudes (convection cells) Sun’s rays (radiation) preferentially heats Equatorial region • Heat air rises and is replaced by air flow toward the Equator from north and south • The hot rising at the Equator cools as it rises and eventually flows away from the Equator the north & south • The cool air descends back toward the Earth’s surface at 30 degrees Climatic Effects
Precipitation Deserts Global Atmospheric Circulation
Sun’s rays (radiation) preferentially heats Equatorial region Heat air rises and is replaced by air flow toward the Equator from north and south The hot rising at the Equator cools as it rises and eventually flows away from the Equator to the north & south The cool air descends back toward the Earth’s surface at 30 degrees Coriolis Effect Causes all moving objects in the Northern Hemisphere to be deflected to the right ...
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- Spring '11