|
|
|
|
|
UpwellingUpwelling is an oceanographic phenomenon that occurs when strong, usually seasonal, winds push water away from the coast, bringing cold, nutrient-rich deep waters up to the surface. Deep water nutrients consist of nutritional salts such as nitrates and phosphates, themselves the result of decomposition of the sea snow. When brought to the surface, these nutrients are processed by phytoplankton and combined with organic compounds such as dissolved CO2, using the energy of the sun through photosynthesis. Upwellings therefore cause very high levels of productivity in phytoplankton compared to other areas of the ocean, and phytoplancton being the basic nutrient of most sea animals, these effects are propagated up the food chain. Currently known regions of upwelling include coastal Peru, Arabian Sea, western South Africa, eastern New Zealand and the California coast, all very rich fishing grounds. Localized upwelling may be due to deflection of deep currents by a seamount providing a nutrient rich island in otherwise low productivity ocean areas. These provide islands of life in such areas and are important to migrating species and human fishing. Upwelling can also occur when tropical cyclones stall over an area, moving at speeds of less than 5 mi/h (8 km/h). The churning of a cyclone eventually draws up cooler water from lower layers of the ocean. This causes the cyclone to weaken. Upwellings also occur in other fluid environments, such as the magma in Earth's mantle or the plasma within a star. They are often a result of convection.
|  | pelican, alaska
skagway, alaska
tenakee springs, alaska
whitestone logging camp, alaska
alcan border, alaska
big delta, alaska
chicken, alaska
delta junction, alaska
deltana, alaska
dot lake, alaska
dot lake village, alaska
| dry creek, alaska
eagle, alaska
eagle village, alaska
fort greely, alaska
healy lake, alaska
northway, alaska
northway junction, alaska
northway village, alaska
tanacross, alaska
tetlin, alaska
tok, alaska
| william sealey gosset
music of spain
eric frank russell
pyrophosphate
rudy weidoeft
chenega, alaska
chisana, alaska
chistochina, alaska
chitina, alaska
copper center, alaska
copperville, alaska
| cordova, alaska
gakona, alaska
glennallen, alaska
gulkana, alaska
kenny lake, alaska
mccarthy, alaska
mendeltna, alaska
mentasta lake, alaska
nelchina, alaska
paxson, alaska
silver springs, alaska
|
|
|
| |
|
|