Introduction+to+Oceanography+(chapters+13-15)

=**Unit 7: Introduction to Oceanography (chapters 13-15)**= ==**Big Idea:** **Oceans play a large role in shaping the earth's surface.**==

ES Standards: 1.3, 1.4, 1.5, 1.7, 1.8, 3.8, 3.9, 3.10, 4.2
=Mapping the Seafloor= >>> >>> >>> >> >>> >>> >>
 * General information
 * 71% of earth's surface is covered with water. Of that, 97% is salt water and the remaining 3% is fresh water. Of the fresh water, 85% is frozen in icecaps, glaciers, icebergs and the remaining 15% is liquid but isn't evenly distributed around the world.
 * Pacific Ocean is the largest and deepest ocean.
 * Oceanography is the study of the world's oceans by using several branches of science (geology, chemistry, biology, physics).
 * Geology Review (unit 1)
 * Plate Tectonics is the movement of lithospheric plates via the mantle. Formed by the convergence of the Continental Drift Theory (Wegner) and Seafloor Spreading (Hess).
 * Lithospheric plates are irregular shaped slaps of solid crust and mantle that move in different directions/speeds.
 * Pacific Plate is the largest lithospheric plate.
 * Oceanic crust is made up of basalt rock and is more dense than continental crust, which is made up of granite rock.
 * 3 Types of plate boundaries
 * Convergent-aka. destructive. Plates that collide together and one plate is forced under another plate (Subduction zone). You can have oceanic-oceanic, continental-continental, or oceanic-continental convergent boundaries. These boundaries make trenches, volcanic mountain chains and islands, and mountain chains and plateaus.
 * Divergent-aka. constructive. Plates that move away from each other. These plates create new ocean floor and are located at the Mid-Ocean ridges.
 * Transform-aka. conservative. Plates that move past each other. Create transform faults.
 * [[image:whs-earthscience/TGA261t.jpg width="400" height="300"]]
 * Bathylmetry
 * Measurement of the ocean depths and mapping of the topography of the ocean floor.
 * H.M.S. Challenger was the first commissioned voyage by the British Royal Naval to collect oceanography data. Left London in 1872 and spent 3.5 years circumnavigating the world's oceans (except for the Arctic Ocean). Mapped depths of the ocean floor using a weighted line marked off in meters. Located the Mariana Trench and information used from this voyage was used to lay trans-continental phone lines.
 * SONAR- Sound Navigation and Ranging uses echosounding to pinpoint distant. Originally invited during WW I for finding enemy subs and mines, SONAR ended up providing the first picture of the ocean floor and its features. A signal is sent and is timed to see how long the signal takes to bounce back to the ship that sent the signal. Knowing sound travels 4900 feet per second in water, the equation S= distance/time can be used to determine depth. Only 5% of the ocean floor has been mapped in detailed by using SONAR and other forms of technology.
 * SideScan sonar is a piece of equipment that is towed by a boat (aka towfish) and it sends out signals mapping the sides of the floor from the instrument but it can't provide depth.
 * [[image:whs-earthscience/sidescan.jpg width="366" height="236"]]
 * Multibean sonar uses several frequencies to not only scan the seafloor but also provide depth.
 * [[image:whs-earthscience/multibeam.jpg width="355" height="243"]]
 * Satellites are used also to monitor the ocean. They use radio altimeters that allow for microwaves to bounce off the ocean. LANDSAT is a satellite that provides information on different ocean features/data
 * Topographic Features on the seafloor
 * Continental Margin
 * 2 types
 * Passive margins are not associated with a plate boundary so there is little/no volcanic or earthquake activity. East Coast of the US is a passive margin
 * Active margins are associated with a plate boundary so there is volcanic and earthquake activity. West Coast of the US is an active margin.
 * Features found within continental margins
 * Continental Shelf- located from the shoreline (where the sea meets the land) to the edge of the self. Average width is 50 m and average depth is 2125 feet. East Coast has a wider continental shelf than the west coast. Area where commercial fisheries hunt for fish, also where oil and natural gas platforms are located. Mineral deposits also along this area.
 * Continental Slope- is a gently sloping region of the continent that meets oceanic crust/floor. Turbidity currents move material from the shelf to the slope and if there are no submarine canyons (cuts in the slope/shelf) sediments accumulate at the bottom of the continental slope. West coast has a lot of submarine canyons than the east coast.
 * Continental Rise- accumulation of sediments carried by turbidity currents. Can create deep sea fans. Not located on Active Continental Margins.
 * Deep-Ocean Basins
 * Trenches- created by convergent plate boundaries in regions called Subduction zones. Associated with Volcanic arc. Tons located around the Pacific Ring of Fire. Mariana Trench has the deepest part of the ocean currently known called the Challenger Deep. It is 11,000 m deep. Was explored in the 1960s but hasn't been visited since then.
 * Abyssal Plains- flat areas of sediments. Atlantic ocean has extensive plains.
 * Seamounts- submarine volcanoes that can breach the surface of water and become volcanic islands. Darwin's theory of Atoll (ring of coral) formation states that coral started out as a fringing reef (reef growing alongside an island) and when the island started to submerge, a barrier reef was formed. Once the island totally submerged, the ring of coral (ATOLL) was left.
 * Guyots- also known as table mounts are seamounts that have been eroded.
 * Mid-Ocean Ridges
 * Located at Divergent Plate boundaries. Extensive underwater mountain chain that is 46,600 miles in length around the ocean floor. Rift valleys along side the mid-ocean ridges is where new magma from the mantle solidifies into new basaltic oceanic crust.
 * Sediments
 * sediments found on the seafloor can help give oceanographers clues to sea climate change. They also can form resources that can be harvested to provide economic value.
 * Different types of sediments are based upon their composition.
 * Biogenous sediments are sediments that are the remains of living things like shells and skeletons. Calcareous ooze is made from forams, Siliceous ooze is from diatoms, and Phosphate ooze is from bones.
 * Hydrogenous sediments are sediments that are crystallized minerals from the water. They can be metal sulfides and evaporites. Mn nodules are solidified structures that contain metals. Calcium carbonates create limestone.
 * Terrigenous sediments are mineral grains from weathered rock.
 * Resources
 * There are many resources obtained from the oceans. Resources such as fish, shellfish, natural gas, oil, gas hydrates, sand/gravel, salts, and Mn nodules.

Ocean Water
>>>> pH of ocean water. >>>> dissociation again of a hydrogen ion from bicarbonate ions creates carbonate ion. This allows for the pH of the ocean water to rise and be more basic than acidic.
 * Salinity
 * amount of dissolved material in water. Measured in parts per thousandths (ppt) or 0/00.
 * Average ocean water salinity is 35 ppt.
 * Largest salt in the ocean water is Sodium Chloride (NaCl) but there are other salts in the ocean water, such as KCl, MgCl, CaCl...
 * Dissolved materials that are added to the ocean comes from weathered and eroded rock from land and from the out-gassing of underwater volcanoes and hyrothermal vents.
 * Ocean water isn't getting saltier because there is a balance between material added and material removed which is keeping the salinity of ocean water constant.
 * Changes in salinity can be due to the amount of fresh water added via runoff, precipitation, and glacial ice melting and the amount of fresh water removed via evaporation due to solar radiation and formation of ice. Latitude location will also determine salinity because of the change in solar radiation as you move away from the equator.
 * Polar regions (60-90 North and South of the Equator) have high salinities due to the fresh water removed as ice which leaves behind the dissolved material.
 * Tropical regions (0-30 North and South of the Equator) have high salinities due to evaporation of fresh water.
 * Open Ocean verses close to the Continent would have a higher salinity because there is less fresh water being added to the open ocean whereas the area by thecontinent would be influenced by runoff.
 * Smaller bodies of water will have a higher salinity than bigger bodies of water because as water is evaporated from the smaller body of water, the volume of water is lower.
 * [[image:whs-earthscience/salinity.gif]]
 * Temperature
 * Main cause in variation in water temperature is due to the latitude. As you move from the equator, the amount of solar radiation changes so therefore the water in the Polar area would be extremely cold whereas the water in the Tropics is extremely warm.[[image:whs-earthscience/temp_salinity_fig3.JPG width="590" height="498"]]
 * Thermocline is the area in ocean water in which there is a sudden change in temperature with depth. Polar regions hardly have a thermocline because the ocean water is cold from the surface to the bottom of the oceanfloor. Temperate regions have alternating thermoclines based upon the seasons. Tropical regions have a thermocline but in order to reach it, depth is greater because of all the solar radiation, tropical water is much warmer than temperate and polar regions.[[image:whs-earthscience/thermo_halo_pycnocline.jpg width="551" height="229"]]
 * Density
 * Measurement based upon the mass per unit volume of an object. Units are g/cm3 or g/mL.
 * Density determines ocean water's vertical position (Ocean Layering). Top 2% of ocean water is referred to as Mixed, 12% of water is Transitional, and 80% of water is Deep based upon water density.
 * Factors that can change density and vary with depth are Salinity (as you add/remove material, you change the mass which will change the density) and Temperature (as water warms up, molecules more spread out therefore volume is greater and density is lower).
 * Pycnocline is the sudden change in density with an increase in depth.
 * Ocean Acidification
 * pH Review
 * pH measures the amount of Hydrogen ions in solution. The greater the number of hydrogen ions, the more acidic a solution is.
 * pH scale ranges from 1-14 with 7 being neutral. Anything less than 7 is considered acidic and anything over 7 is considered basic.
 * Buffers are solutions used to prevent a substance from becoming too acidic or too basic.
 * Average pH of ocean water is 8.2
 * Carbonate Buffer
 * Ocean water has a way of dealing with the naturally made Carbonic Acid by removing a Hydrogen ion or two to make either bicarbonate or carbonate ions.
 * [[image:whs-earthscience/carbonatebuffer.jpg]]
 * Water and Carbon Dioxide form carbonic acid which lowers the
 * Water and Carbon Dioxide form carbonic acid which lowers the
 * Dissociation of a hydrogen ion from carbonic acidcreates bicarbonate ions and
 * [[image:whs-earthscience/carbonatebuffer2.jpg width="337" height="216"]]
 * Organisms can use the carbonate ion to form with calcium ions to make calcium carbonate. This compound is used to make limestone rocks and shells of many marine creatures.
 * [[image:whs-earthscience/calciumcarbonate.jpg]]
 * Ocean Acidification is when too much carbon dioxide enters the water creating large quantities of carbonic acid that can't be dissociated quickly by the carbonate buffer so the pH of the water drops. As the pH lowers (becomes more acidic) it prevents creatures from being about to use the carbonate ion to make their shells and deforms shells of organisms.
 * [[image:whs-earthscience/oceanacidification.jpg]]
 * [[image:whs-earthscience/shells_oceanacidification.jpg]]
 * [[image:whs-earthscience/shells_oceanacidification.jpg]]

Marine Life
>>> Such types of creatures that would be in this category are: fish, dolphins, turtles, sharks, whales. >>>>
 * Classification of sea life is based upon their characteristics such as their mobility and where they live (location). Most sea life lives within the **euphotic** and **epipelagic** regions of the ocean.
 * Three categories for sea life.
 * **Plankton-** these are the drifters/floaters found mainly in the **euphotic** and **epipelagic** regions. They are moved from place to place by wind, waves, and current. There are different types of plankton such as **//phytoplankton//** (the photosynthesizers-autotrophs) and the **//zooplankton//** (the consumers-heterotrophs). Not all plankton are microscopic as seen with krill and jellyfish (**//meroplankton//**...only a portion of their life is spent microscopic/small). Microscopic plankton such as diatoms and dinoflagellates are considered //**holoplankton**// because they will stay small/microscopic their entire life. Plankton is what feeds EVERYTHING in the ocean whether directly or indirectly. Such types of creatures that would be in this category: jellyfish, krill, diatoms, fish larvae, crab larvae
 * **Nekton-** these are the swimmers. They are any creatures that actively swims looking for food. They are most abundant near the continent but can also venture into open ocean water.
 * **Benthos**- these are the bottom dwellers, creatures that are mainly on/near the ocean floor or in the ocean floor sediment. Those creatures that are //**epifauna**// are found on the oceanfloor. Such examples would be flounder, sea urchins, lobster, crabs. Those creatures that are found within the oceanfloor sediment are considered **//infauna//.** Such examples would be oysters, polycheat worms, garden eels. 98% of all sea live would fall within this category.
 * [[image:whs-earthscience/lifegroups.jpg width="525" height="521"]]
 * **Marine Life zones** are determined based upon the amount of light present, the distance from shore (land), and the depth of the water.
 * Light Zones are areas where sunlight intensity is found. These zones can be altered based upon the amount of light present, the sediments in the water, and by decay of organisms.
 * Euphotic zone: referred to as the "true light" zone because all wavelengths of light can be found in this region. This region is located from the surface of ocean water to 100 m (330'). This is the area of greatest photosynthesis. Phytoplankton will be abundant in this region.
 * Dysphotic zone: this area is where the intensity of the sunlight starts to diminish. This region goes from 100m to 1000m in depth. Creatures in this region display bioluminescence.
 * Aphotic zone: this area is completely voided of light. This region starts at 1000m and extends to 11000m. This zone is also extremely cold and pressure increases as depth increases so creatures have to be adapted to living in this area. There is little nutrients in this region and most food comes in the form of detritus from regions above.
 * [[image:whs-earthscience/lightzones.jpg width="320" height="228"]]
 * Benthic zones are areas that deal with land and the distance from shore.
 * Supralittoral zone is the region above the high tide line. Here water only reaches during storms (hurricanes, Nor'easters).
 * Littoral zone is the region between the high tide and low tide (intertidal) areas. This area is the area of greatest challenge and change for organisms so organisms have to have adaptations to allow them to survive long periods of no water. Barnacles close to conserve water the same with periwinkle snails. Oysters and crabs will burrow into the sand to wait out low tide.
 * Sublittoral zone is also known as the subneritic zone. This region is from the low tide line to the edge of the continental shelf. Since water is constantly found here creatures do not have to worry about changes in water levels, temperature, etc. This area is the richest in marine biodiversity.
 * Suboceanic deals with any land from the edge of the continental shelf to ocean floor.
 * bathyal region is the land that involves the continental slope and submarine canyons to the continental rise.
 * abbyssal region is the land that involves the abyssal plains and any features on these planes, seamounts, guyots, midoceanic ridges.
 * hadal region is the land within the trenches (6000m+ in depth).
 * [[image:whs-earthscience/lifezones2.jpg width="421" height="298"]]
 * Pelagic zones deal with the water or depth of water.
 * Neritic region is the water that is found from the sublittoral region to the edge of the continental shelf. This area is rich in nutrients therefore is also rich in biodiversity.
 * Open Ocean (oceanic) region is the water from the edge of the continental to deep ocean floor. This area is low in nutrients so nutrients are brought from lower levels to the surface during upwelling events.
 * Epipelagic is the region from 0m to 200m. This is the region in which the euphotic zone is located. This area is high in primary productivity.
 * Mesopelagic is the region from 200m to 1000m. This area has the minimum Oxygen zone, area with the least amount of oxygen present in ocean water. This is mainly due to the fact that there are no photosynthetic creatures located in this region because this area falls within the dysphotic zone.
 * Bathylpelagic region is roughly from 1000m to 4000m.
 * Abyssalpelagic region is roughly from 4000m to 6000m.
 * Hadalpelagic region is roughly from 6000m to 11000m and deals with the water within the trenches.


 * **Productivity**
 * It is the amount of carbon that is fixed by photosynthesis (uses light to make food) or chemosynthesis (doesn't use light but chemicals to make food).
 * Primary Producers: chemotrophic bacteria in hydrothermal vents, phytoplankton, algae, and marine plants are considered primary producers because they fix inorganic carbon into organic molecules such as sugars (food).
 * How much productivity depends upon the amount of nutrients available and the amount of solar radiation.
 * Temperate regions are higher in productivity because of the nutrients available but only seasonal due to the change in the amount of solar radiation received.
 * Tropical regions are lower in productivity because of lack of nutrients and not due to lack of solar radiation.
 * Regions closest to shoreline(Neritic region) are higher in productivity than regions in open ocean (oceanic zones) due to the abundance of nutrients.
 * [[image:whs-earthscience/productivity.jpg width="558" height="328"]]
 * Feeding Relationships
 * Food chains are individual linkage systems showing what is eating what. Food webs are complex systems in which there are many food chains.
 * Trophic levels are levels within a food chain/food web. The bottom level is where the primary producers would be found followed by the primary consumers, than secondary consumers, then tertiary consumers. As energy is moved from trophic level to trophic level only 10% of the energy available at one level moves to the next level. Creatures are using up 90% of the energy they receive to do normal functions such as growth, repair, reproduction.
 * Symbiotic Relationships
 * Symbiosis by definition is the relationship between two organisms. There are different types of symbiotic relationships in which the symbionant and the host interact closely with each other.
 * Mutualism is the type of relationship that both the symbionant and the host benefit from the relationship. For example, cleaning stations are areas on a reef in which creatures can have parasites cleaned off their skin/shell/scales by other creatures. The symbionant is the cleaning creature and the host is the one getting a cleaning. Both creatures benefit from this relationship: symbionant gets food, host has parsites removed.
 * Commensalism is the type of relationship in which only the symbionant benefits from however the host is neither harmed or benefited. For example, Aarow crabs hide amongst the nooks and crannies of coral. They are not providing a service for the coral (the host) but are benefiting form a place to hide from predators.
 * Parastism is the type of relationship in which the symbionant benefits while the host is harmed. Parastic relationships don't always end in death for the host but they do harm the host. For example, the Pinhead Pearlfish is a parasite that uses the body of the sea cucumber for protection and a food source eating the gonads of the sea cucumber. Some speices of Pearlfish are not parasitic some are actually commensalism.
 * Predator/Prey relationships involve autotrophs and heterotrophs. Creatures have developed adaptations to prevent being prey to larger predators.
 * **Competition** is where you have competing species looking for the same resources: mate, home, food.

Circulation

 * Currents are large circulations of water created by the Earth's rotation, density, and wind.
 * **Coriolis Effect** is the apparent shift in the pathway of any fluid above the earth's surface due to the Earth's rotation.
 * Northern Hemisphere- fluids (water, air) are deflected to the right (clockwise)
 * Southern Hemisphere-fluids are deflected to the left (counterclockwise)
 * Further from the equator, more predominant the affect is seen on a fluid.
 * **Gyre** is a large movement of water. There are 5 gyres in the ocean: North Atlantic Gyre, South Atlantic Gyre, North Pacific Gyre, South Pacific Gyre, and Indian Ocean Gyre. All created by surface currents.
 * There are 2 types of ocean currents found on earth.
 * **Surface currents**- These currents are located within the first 200m of ocean water and are created by the global winds (winds that move in one direction over long distances). Currents move in the direction of the wind and can be short or long lived currents. Landmasses will influence if the currents are short or long-lived. Warm surface currents originate at the equator and move to the poles bringing warm water (ie: Gulf Stream Current). Cold surface currents originate at the poles and move to the equator bringing cold water (ie: California Current). Some surface currents can travel around the world and some are localized.
 * **Deep Currents-** These currents are located near the ocean floor and are created by density differences. These currents move in the opposite direction of surface currents. They are responsible for transferring heat from the tropics to the poles and cold water from the poles to the equator. (Giant Conveyor Belt-North Atlantic)
 * **Upwelling events** are created when wind moves warmer surface water offshore allowing for colder deep water to come tot he surface. The colder deep water has more oxygen and this event brings oxygen up to the top layer of water for the creatures.
 * **Localized Currents** are currents found along the coastlines.
 * Longshore currents- currents that moves parallel to the shoreline and is responsible for moving material down a beach.
 * Rip currents- currents that are created due to a break in a sandbar which causes a large amount of water to pass through a short location. These currents are perpendicular to the shoreline and are extremely strong.
 * Tidal currents- currents that are crated by the changing of the tides.

Shoreline

 * Definition of the shoreline is where the land meets the sea. The area that changes with the tides.
 * Coastline is the landward limit/seaward edge. This area is classified based upon the rise/fall of sea level.
 * Emergent coastlines are areas where land that was underwater is now above water due to a drop in sea level. Features predominant with an emergent coast are wave cliffs and platforms.
 * Submergent coastlines are areas where land that was above water is now drowned/below water due to a rise in sea level. Features predominant with a submergent coast are estuaries.

Waves

 * Terminology
 * Wavelength- distance between the top of a wave (crest) and the top of the next consecutive wave.
 * Wave height-distance between the trough (bottom of a wave) and the crest of the same wave.
 * Wave period- time it takes waves to pass a given point. (T=1/f)
 * Wave frequency-number of waves passing a set point in a set period of time. (f=1/T)
 * Wavelength and wave height depends upon the speed of the wind, the fetch, and the duration of the wind.
 * Orbital motion of water molecules change as waves approach the shoreline. As the water becomes shallower, the wave 'feels bottom' causing the circular orbit to become elliptical. Height of the wave rises as it gets closer to the shoreline.
 * Waves help to transport material up and down a beach.
 * Erosion happens along the coastline and caused by wave pressure and abrasion.
 * Wave refraction is when waves bend because the front portion of the wave slows down.
 * Beach Drift is the movement of material down a beach in a zig-zag pattern based on waves.
 * Longshore currents run parallel to the shore and move material down the beach.
 * Features created by wave erosion
 * Wave-cut Cliff- feature found along a shoreline caused by wave erosion
 * Sea Arch (natural bridge)- caused by wave erosion; forms an arch
 * Sea Stack- eroded sea arch; stack of rock within the water
 * Spit-sandbar that is attached to the land; usually has a hook at one end. Created by longshore currents
 * Baymouth Bar-sandbar that cuts off a body of water (ie: bay) from the ocean; created by a longshore current
 * Tombolo- sandbar that connects the land/continent to an island; creatued by a longshore current
 * Longshore Bar-sandbar that is parallel to the shoreline; created by a longshore current
 * Barrier Island-island that was produced by a collection of sand over time; created by longshore currents and are located off the coast of the mainland
 * Stabilization of Shorelines
 * Hard Stabilization-man-made structures constructed to prevent or slow down coastal erosion
 * Groin/Jetty-structures that are built perpendicular to the shore; job is to keep a water way open (ie: river) to the ocean. Prevents longshore current from moving sediments down a beach so a portion of the beach grows with the accumulation of sand (upstream from the jetty) while the other portion of the beach is starved of sand (downstream of the jetty).
 * Breakwater-structures built parallel to the shoreline; job is to slow down or break waves so there isn't a lot of energy hitting the coastline. Causes erosion in areas were breakwaters aren't found.
 * Seawall-structures built right along the shoreline to prevent erosion of land behind the seawall. Causes erosion of sediments at the base of the seawall.
 * Beach Nourishment-way to deal with loss of sediment at the coast dumping sand onto eroded beaches at the beginning of the season.

Tides

 * Regular rise and fall of the ocean due to the gravitational pull of the moon on the earth's water. The sun also exerts a gravitational pull on the waters but it isn't as strong as the moon's pull due to the moon is closer to the Earth than the sun.
 * Different types of tides happen around the world.
 * Diurnal tides are where regions experience 1 high tide and 1 low tide a day. (Caribbean islands)
 * Semidiurnal tides are where regions experience 2 high tides and 2 low tides a day that are at the same height. (Wareham...high tides are 3.5')
 * Mixed tides are where regions experience 2 high tides and 2 low tides a day BUT they are not the same height. (Nova Scotia)
 * Special Tides are caused due to certain phases of the moon.
 * Spring Tides happen when the moon is at New and Full phases. This causes tides to be much higher than they normally are due to the pull of BOTH the sun and moon on the Earth. For example, if regular high tide here in Wareham is 3.5' then during a Spring tide, the high tide could be around 8'.
 * Neap Tides happen when the moon is at First and Last Quarter phases. This causes tides to be much lower than they normally are due to the moon pulling on the earth from one direction and the sun from a different direction. For example, if regular high tide here in Wareham is 3.5' then during a Neap tide, the high tide could be around 1'.