Unit 5: Oceanography

General Information 70% of the world is covered by water Types of research –Core Samples –Mini Submarines –Satellites

Properties of Water Density –Cold water is more dense than warm –Ice is less dense than liquid water BP= 100 C FP = 0 C Polarity –Water molecules have a (+ and — ) charge –Water molecules attract substances with ionic bonds –Water with dissolved ions is called a solution

Properties of Ocean Water Dissolved Ions –Chlorine and Sodium –Salinity refers to the amount of dissolved salt –Salinity increases the density of water Salinity varies slightly from place to place –Evaporation increases salinity –Freshwater decreases salinity

Temperature Profile Surface –Water is mixed by wind –Temperature is relatively uniform Middle Zone –Thermocline: a rapid drop in temperature Deep Water –Cold near freezing

Ocean Life Phytoplankton : single celled plants Zooplankton: single celled animals

Ocean Floor Ocean Floor : Methods of Study –Sonar: Bounce sound waves off bottom –Core Sample: study of ocean floor –Satellites: detect changes in the surface of ocean water

Ocean Floor Continental Margin –Continental Shelf: extension of continent –Continental Slope: where shelf drops into ocean basin –Continental Rise: sediment buildup at the bottom of the basin –Submarine Canyon: eroded into slope by turbidity currents

Active and Passive Margin

Submarine Canyon

Ocean Floor Ocean Basin –Abyssal Plain ; flattest area of ocean floor –Deep sea trench: formed at subduction boundary –Seamounts and Guyots: mountains that rise from the ocean floor –Mid-Ocean Ridge- center of seafloor spreading

Transform faults

Formation of an Atoll

Ocean Floor sediments Terrigenous: (nonliving) sand, mud and clay Biogenious: (living) made up of microscopic shells Hydrogenous: formed by a chemical reaction causing sediment to precipitate out of water

The Movement of Ocean Water Ocean current: any continuous flow of ocean water Winds drive Surface Currents –Clockwise in the Northern Hemisphere –Counterclockwise in the Southern Hemisphere –Warm Currents originate at the equator –Cold currents originate at the poles –Countercurrents flow in opposite direction from windblown currents

The Movement of Ocean Water Currents Under The surface –Density Currents Move slowly Caused by: temperature, sediments(turbidity) and evaporation –Cold waters from the poles create density currents –Evaporation in the Mediterranean creates density currents –Upwelling: caused by winds parallel to shore

Tides Created by the pull of gravity from the moon and sun Spring tide: highest tide Neap tide: lowest tide