Why should I be aware of this?
The oceans contain most of the Earth's water and carbon and surface heat, and much of its biomass. Together with the atmosphere, continents and ice-cover (the cryosphere), the oceans form a working machine, driven mostly by energy from the sun. Lesser amounts of energy derive from tides raised by the moon and sun and planets, and heat from the Earth’s interior.
All about Oceanography
Modern oceanography began in the 1760s and uses insights from biology, chemistry, geology, meteorology, and physics to analyze ocean currents, marine ecosystems, ocean storms, waves, ocean plate tectonics, and features of the ocean floor, including exotic biomes such as cold seeps and hydrothermal vents
Four categories of Oceanography
Oceanography is divided into four general categories:
- Biological oceanography (marine oceanography)
Studies of biological oceanography involve the ecology of phytoplankton, zooplankton and fish populations and the oceanographic determinants of biological production in the world's oceans. The physical and chemical factors that affect the distribution and abundance of estuarine and marine plankton is being investigated.
- Chemical oceanography (marine chemistry)
Studies of trace metals in sea water are aimed at understanding the global biogeochemical cycles that control the distribution of elements in the oceans. The geochemists are well equipped with specialized sampling gear for the contamination-free collection of sea water and sediments.
- Geological oceanography (marine geology)
The focus of marine geological and geophysical work is deep seismic exploration and is carried out at sea using sea-floor seismometers, and large-volume air gun sources are used for continuous seismic profiling. The petrology and chemistry of dredged rocks are studied in order to identify the compositional variability of the magma chambers and to locate possible mantle plumes of hot spots.
- Physical oceanography (marine physics)
This is the study of the physics of the oceans, including the complex ways that light, sound, and radio waves traverse the ocean. Research in Physical Oceanography and Atmospheric Science may be pursued in many areas, including elucidation of the influence of tides, winds and freshwater runoff.
Oceanography is also heavily used in ocean engineering, commercial or scientific ventures involving the construction of oil platforms, ships, harbors, and maybe in the future, floating cities.
- The oceans cover 71% of the Earth's surface and contain 97% of the Earth's water. Less than 1% is fresh water, and 2-3% is contained in glaciers and ice caps.
- Average depth of the oceans is 2.5 miles (4km). The deepest point lies in the Mariana Trench, 6.8 miles (10.9km) down. Mount Everest is only 5.5 miles (8.8km) high.
- The temperature of almost the entire deep ocean is only a few degrees above freezing, 39F (4C).
- Humans can barely see light below 1600 ft. (500m), at about one-millionth of the intensity at the surface.
- The majority of the deep ocean is under 3000 to 9000 pounds of pressure per square inch (or around the equivalent of 100 to 300 times the air pressure in automobiles tires).
- Deep sea waters (depending on depth and pressure) can force the air pockets out of, and shrink a Polystyrene cup (the research sub and divers are protected by the materials the sub is constructed of, metals, etc.)
The study of the oceans is intimately linked to understanding global climate changes, potential global warming and related biosphere concerns. The atmosphere and ocean are linked because of evaporation and precipitation as well as thermal flux (and solar insolation). Wind stress is a major driver of ocean currents while the ocean is a sink for atmospheric carbon dioxide.
- What is Oceanography?
- What is Oceanography?
- ↑ Absolute Astronomy