Ocean Properties

This power point is a compilation of some of the best power point

presentations given by students in class.

El Nino

El Niño?• El Nino was first discovered as a oscillation

by Gregory T. Cushman

• a periodic change in the currents of the Pacific Ocean that occurs every five to eight years and brings unusually warm water to the coast of northern South America.

El Niño Effects

• Eastern pacific water warms up

• Higher surface air pressure

• 6-8 degrees Celsius warmer

• Warmer eastern pacific waters cause the ecosystem to change dramatically

• Can cause droughts and food shortages,

El Niño Negative Effects

• Sea surface temperature in the equatorial

pacific ocean • El Nino is characterized by unusually warm

temperatures• La Nina by unusually cool temperatures in the

equatorial Pacific. • El Nino is characterized by unusually warm

temperatures• Sea surface temperature in the equatorial

pacific ocean

Anomalies represent deviations from normal temperature values, with unusually warm temperatures shown in red and unusually cold anomalies shown in blue.

• Rise in surface pressure over the Indian Ocean, Indonesia, and Australia

• Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean

• Trade winds in the south Pacific weaken or head east

• Warm air rises near Peru, causing rain in the northern Peruvian deserts

• Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific.

How often does it occur?

About every 2-7 years for 6 months

• Are all el Nino’s the same ?

• They are somewhat different in magnitude and in duration

• http://youtu.be/IvmeUStFvz8

• http://youtu.be/SR5VPAqVQBw

Ocean Currents

SURFACE CURRENTSSURFACE CURRENTSCORIOLIS EFFECT: THE APPARENT DEFLECTION OF A BODY IN MOTION WITH RESPECT TO THE EARTH.

GYRES: ANY LARGE SYSYTEM OF A ROTATING OCEAN CURRENT, PARTICULARLY THOSE INVOLVED WITH LARGE WIND MOVEMENTS. THEY ARE CAUSED BY THE CORIOLIS EFFECT.

CLASSIFICATIONS OF CLASSIFICATIONS OF CURRENTSCURRENTS WESTERN BOUNDARY CURRENTS

•SURFACE CURRENTS ARE LOCATED ON THE WESTERN SIDE OF THE SUBTROPICAL GYRES.•WESTERN BOUNDARY CURRENTS TYPICALLY MOVE 40 TO 120 KM/ DAY

EASTERN BOUNDARY CURRENTS•EASTERN BOUNDARY CURRENTS, SUCH AS THE CALIFORNIA CURRENT AND THE CANARY CURRENT, ARE SLOWER, SHALLOWER, AND WIDER THAN WESTERN BOUNDARIES.•FOUND IN THE EASTERN SIDE OF OCEANIC BASINS.• RELATIVELY SHALLOW, BROAD, AND SLOW FLOWING.

TWO TYPES OF CURRENTS… SURFACE CURRENTS: MAKE UP ABOUT 10% OF THE WATER IN THE OCEAN. DEEP OCEAN CURRENTS: MAKE UP 90% OF ALL WATERS.

CLASSIFICATIONS CLASSIFICATIONS CONTINUE…CONTINUE…TRANSVERSE CURRENT: A CURRENT

THAT FLOWS EITHER EAST OR WEST. THE STRONGEST TRANSVERSE CURRENTS ARE EQUATORIAL CURRENTS WHICH ARE DRIVEN BY THE TRADE WINDS.

BIOLOGICAL IMPACT: •OCEAN CURRENTS CARRY WARMER WATER FROM THE TROPICS INTO COLDER REGIONS. •CURRENTS THAT UPWELL PLAY A HUGE ROLE IN MARINE PRODUCTIVITY.•WHEN CURRENTS UPWELL THEY SWEEP VITAL NUTRIENTS BACK WERE THEY ARE NEEDED MOST.•DOWNWELLING PROVIDES OXYGEN FOR THE ORGANISMS AT THE BOTTOM OF THE OCEAN.

Ocean Layers

Characteristics of Ocean Layers• Scientists have divided the ocean into five

main layers. These layers known as deep zones

• The deeper into these unknown places the temperatures decrease and the pressure increases.

• Some of the most strange and interesting creatures in the sea can be found.

Deep Water Circulation

• Deep waters are "formed" where the air temperatures are cold and where the salinity of the surface waters are relatively high. The combinations of salinity and cold temperatures make the water denser and cause it to sink to the bottom.

• Deep water circulation in the oceans, referred to as the thermohaline circulation, or sometimes the "Oceanic Conveyer Belt".

Upwelling and downwellingUpwelling

• Our currents are costal and ocean phenomenons that keep the ocean ecosystems going

• Upwelling current deep water is pulled up as the surface water moves away from the land

downwelling

• Down welling currents winds blow surface water toward a coast line where the water accumulates and sinks

• Three types of current systems are equarotal, costal and seasonal

UPWELLING DOWN WELLING

Waves and Tides

Why do Tides Occur?

• Tides occur due to the gravitational force of the moon, and the sun, and due to the rotation of the Earth. The gravity pulls the water up toward up as far as it can, creating high tide. When the moon or sun is not on the same side, it creates low tides

Spring Tides

• Happens when the moon is either full or new. Also the gravitational force of the sun is combined with the moon to create a really high tide. It only occurs when the Earth, Sun and Moon are aligned.

Neap Tides• Happens when the moon is in its quarter phase and the moon and sun work at right angles. This creates little difference between high and low tides. They occur when the gravitational force of the moon and sun are perpendicular to one another.

Things to Know About Tides• Tidal Range- The Vertical difference between the high tide and the low tide.

• Diurnal tides- they have a single high tide and a single low tide per day.

• Semidiurnal Tides- they have many daily inequity where the high tides have different heights. You can predict these tides due to a long length of time after the moon as passed overhead.

Things to know Etc.

• Other factors influence tides such as underwater Bathymetry( the depth of the water), and the coast line shape.

• Each location on earth is affected by tides differently

• There is a delay between the phases of the Moon and the effect on the tide.

• Springs and neaps in the North Sea for example, are two days behind the new/full moon and first/third quarter moon. This is called the tide's age.

Salinity

Composition of Salt Water- Salinity is the measurement of all total salts that are dissolved in the water.

-Worlds oceans usually have 35% (one liter per volume)-Salinity of salt water is usually measured in 35 parts per thousand ( also written o/oo) in most marine areas. - The majority of salt in the ocean is Sodium Chloride (table salt)

-Other elements include :-Sulfate -Calcium-Magnesium -Potassium-Bicarbonate -Bromide-Borate -Strontium-Flouride -and many more

Evaporites

• Areas where minerals precipitate out of salt water because of both the reasons that high concentrations of minerals in the water and higher rates of evaporation than water input

• Graben: depressed block of land surrounded by parallel faults. German for ditch.

– Graben areas in continental rift environments are fed by limited ravine drainage. Usually found in sub tropical or tropical environments

– In oceanic rift environments they are fed by limited oceanic input, which will eventually lead to isolation and then evaporation. I.e. Red Sea

• The internal drainage basin tend to be in arid to semi-arid temperate to the tropical environments which are fed by ephemeral drainage.

-The Great Salt Lake in Utah•Non-basin areas are supplied water through by ground water seepage (artesian waters)

-The seep mounds in the Victoria Desert which is fed by the Artesian Basin, Australia

How They are Formed

• Not only composed of halite salt, but most formations do not contain more than a few percent of evaporite minerals, the remainder being composed of the more typical detrital clastic rocks and carbonates.

• Major groups of evaporites – Halides- halite sylvite (KCl), calcite, and flourite

– Sulfates- gypsum, barite, and anhydrite

– Nitrates- nitrate (soda niter) and niter

– Borates – typically found in arid-salt-lake deposits which are bountiful in the southwestern U.S.