Ocean

Do NowWhat is the difference between an ocean & a sea?List 2 oceans & list 2 seasOceanChapters 23 & 24Ch. 23 sec 1Global Ocean - body of salt water that covers nearly three-fourths of Earths surfacecontains more than 97% of all of the water on Earthdivided into five major oceans:1. Pacific Ocean Largest2. Atlantic Ocean 3. Indian Ocean 4. Southern Ocean5. Arctic Ocean Smallest

SeasSea - large, commonly saline body of water that is smaller than an ocean & that may be partially or completely surrounded by landEx. Mediterranean Sea, Caribbean Sea, & South China Sea

OceanographyOceanography - scientific study of the ocean, including the properties & movement of ocean water, the characteristics of the ocean floor, & organisms that live in the ocean

Studying the Ocean DepthsSonar (sound navigation and ranging)- a system that uses acoustic signals & returned echoes to determine the location of objects or to communicateused to make maps & profiles of the ocean floor

Studying the Ocean DepthsSubmersibles - underwater research vesselsBathysphere - remains connected to the research ship for communications & life supportBathyscaph - is a self-propelled, free-moving submarine

Ch. 23 sec 2The ocean floor can be divided into two major areas:1. Continental margin shallow sea floor located between the shoreline & the deep-ocean bottom2. Deep-ocean basin - part of the ocean floor that is under deep water beyond the continental margin

Deep- ocean basinFeatures of the Ocean FloorTrenches - long, narrow, & steep depression that forms on the ocean floor

Abyssal plain - large, flat, almost level area of the deep-ocean basin

Mid-ocean ridges - form underwater mountain ranges that run along the floors of all oceans

Seamounts - submerged volcanic mountains that are taller than 1 km. They form in areas of increased volcanic activity called hot spots.

Sea Floor Topography

Do NowWhat does sonar stand for & what is it used for?Ch. 24 sec 1Ocean water is a complex mixture of chemicals that sustains a variety of plant & animal life.The main gases dissolved in ocean water = O2 & N2Gases can enter the ocean from streams, volcanoes, organisms, & the atmosphere.Ocean water is 96.5% pure water, or H2ODissolved solids, commonly called sea salts, give the ocean its salty taste.

Salinity & The ThermoclineSalinity - measure of the amount of dissolved salts in a given amount of liquidThermocline - layer in a body of water in which water temperature drops with increased depth faster than it does in other layers

Ocean ColorThe color of ocean water is determined by the way it absorbs or reflects sunlight.Much of the sunlight is absorbed by the waterOnly the blue wavelength tends to be reflectedThe reflection makes ocean water appear blue

Do NowWhat are three classifications of marine life?What do we base these groups on?Ch. 24 sec 2Marine organisms help maintain the chemical balance of ocean water.removing nutrients & gasesnutrients are eventually returned to the water when the organism dies

UpwellingElements are then released back into the ocean water when organisms die, sink to lower depths, & decay. So, deep water is a storage area for nutrients needed for life.Upwelling - movement of deep, cold, and nutrient-rich water to the surface

Three Groups of Marine LifeOrganisms are placed in groups based on where they live and how they move

Plankton Nekton Benthos

PLANKTONOrganisms that float or drift freely near oceans surfaceMicroscopicFood for many organisms

Phytoplankton plant likeProvides most of Earths oxygen2. Zooplankton animal like

NEKTONSwim actively in open ocean mammals like whales, dolphins, & sea lionsfish

BENTHOSLive on or in ocean floor

Crabs, starfish, worms, coral, sponges, seaweed, and clams

Ocean EnvironmentsBenthic (BOTTOM) zone - bottom region of oceans & bodies of fresh waterPelagic zone - region of an ocean or body of fresh water above the benthic zone

The amount of sunlight, the water temperature, & the water pressure determines the distribution of marine life within these zones.

Benthic (BOTTOM) ZonesIntertidal zone - shallowest, between the low-tide and high-tide linesSublittoral zone - most organisms live hereBathyal zone - begins at continental slope - 4,000 m.Abyssal zone - no sunlight , 4,000 m - 6,000 m.Hadal zone - ocean trenches, deeper than 6,000 m

Pelagic ZonesNeritic zone - area of the pelagic zone above the continental shelveOceanic zone - extends into the deep waters & divided into four zones, based on depth:Epipelagic SHALLOWMesopelagicBathypelagicAbyssopelagic DEEPEST

Zones

Ch. 24 sec 3Food from the OceanBecause fish are a significant food source for people around the world, fishing has become an important industry.When the ocean is overfished, or overharvested, over a long period of time, fish populations can collapse.

Fresh Water from Salt Water?Desalination extraction of fresh water from salt waterDistillationOcean water is heated to remove saltFreezingFreezing water to remove saltReverse Osmosis DesalinationUses special membranes to filter salt

All methods are time consuming & costly!Minerals & ResourcesSalt Petroleum most valuable (oil) of the worlds oil comes from offshore wellsNodules potato-shaped lumps of minerals (manganese, iron, copper, nickel, cobalt, & phosphates) from ocean floor Expensive & dangerous to obtainMagnesiumBromineFoodAquaculture - raising of aquatic plants and animals for human use or consumptionProblem: ocean farms are susceptible to pollution