Properties of Ocean Water Chapter 17

Oceanography The scientific study of the oceans and the life within the oceans.

4 Oceans Pacific Atlantic Indian Arctic

The Physical Geography of the Sea Book written by Matthew Fontaine Maury in 1855 from logbooks of sea captains. Contained charts of winds and currents. First scientific book written in English about the oceans.

Challenger 1872, 4 year voyage resulting in a 50 volumes of reports as to depths, water and sediment samples, temperatures, plant and animal specimens and ocean currents.

JOIDES Resolution Seagoing drilling platform. Designed to sample rocks and sediments of seafloor. Can remain in the same spot while drilling into the seafloor by help of computers.

Alvin Tiny, battery powered submarine. Can ascend to depths of 4000 meters with 3 people. Can collect samples, take temperature readings, electric conductivity, and dissolved oxygen readings.

Argo Undersea sled that carries powerful lights, undersea radar and cameras. Towed behind a ship.

HMS Titanic Dubbed the “unsinkable”, hit an iceberg and sank on its maiden voyage from England to the U.S in 1912.

Jason, Jr. or J.J Small robot submarine carried by Alvin. Lights and cameras onboard.

Salinity The measure of dissolved solids found in seawater. Mostly sodium chloride. (NaCI)

Electrical Conductivity A method of determining salinity in ocean water. The higher the salinity, the greater the current.

Water Masses The mass of a body of water is determined by its source region. When both temperature and salinity are known, density can be determined.

Mixed Layer Also known as the surface layer, thickness depends on latitude. At high latitudes and the equator about 100 meters, mid-latitudes as thick as 300 meters. Winds and waves mix the heat evenly throughout the zone. Only present where sunlight is abundant enough to grow phytoplankton.

Thermocline Area of rapid temperature change at around 1000 meters in the ocean. Water temperature can drop to as low as 2oC.

Phytoplankton Most important group of microscopic plants in the mixed layer that float and drift with the waves and currents. Basic food source for the ocean, make food through photosynthesis.

Diatoms Most abundant type of phytoplankton. One celled organisms that build thick shells made of silica.

Zooplankton Microscopic animals that eat phytoplankton and in turn are eaten by everything from tiny fish to the great whales.

Nekton “Swimmers” an ocean animal that can propel itself to escape predation, catch food and reproduce.

Benthos “Attachers” Animals that attach to other organisms or solid surfaces to survive.

Black Smokers Ocean floor vents, hot water mixes with the iron sulifade (hydrogen) surrounding the vent to turn black in color. 380 degrees Celsius. Temperatures occur when water comes in contact with hot basaltic rock and dissolves minerals and gases into the water.

Mining of Sea Water There are 55 known elements in sea water including gold, silver, copper and uranium. All are found in extremely small amounts, less than 4 parts per trillion. Mining of these would not be profitable. Magnesium is the exception. Mg can be extracted from ocean water more easily than the process on land. (Evaporation of sea water)