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Oceans and their Coastal margins
Index
Introduction to Oceans
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Where are the world's Oceans?
Oceans of the world
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Currents of the world
Warm Currents (red)
Cold Currents (blue)
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| introduction_to_oceans_-_handout.docx |
Ocean Floor Morphology
Go through the PowerPoint on the Structure of the Earth as a reminder of how plates move. You do not need to know this for the IB syllabus but it is important to have an understanding of how tectonics have influenced the sea floor.
| plates.ppt |
Ocean floor morphology
| oceanmorphology-110913233631-phpapp02.ppt |
Oceanic Water
Averages
- Temperature: Below 1000m there is a uniform average of 2°C
- Salinity: 35 parts per thousand (ppt)
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Using the next three diagrams.
Ocean temperature related to depth - Thermocline
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Global ocean surface temperatures
Global ocean salinity
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Oceans and Climate
The Oceanic Conveyor Belts
Ocean conveyor belt
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Stage 1:
Cold, salty, dense water sinks at the Earth's northern polar region and heads south along the western Atlantic basin. 
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Stage 2:
The current is "recharged" as it travels along the coast of Antarctica and picks up more cold, salty, dense water. 
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Stage 3:
The main current splits into two sections, one traveling northward into the Indian Ocean, while the other heads up into the western Pacific. 
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Stage 4:
The two branches of the current warm and rise as they travel northward, then loop back around southward and westward. 
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Stage 5:
The now-warmed surface waters continue circulating around the globe. They eventually return to the North Atlantic where the cycle begins again. 
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3D perspective of the thermohaline flow
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Sea surface density (salinity)
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Sea Currents (surface)
(www.noaa.gov/)
Coastal currents are affected by local winds. Surface ocean currents, which occur on the open ocean, are driven by a complex global wind system.
(www.noaa.gov/)
Coastal currents are affected by local winds. Surface ocean currents, which occur on the open ocean, are driven by a complex global wind system.
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If the Earth did not rotate and remained stationary, the atmosphere would circulate between the poles (high pressure areas) and the equator (a low pressure area) in a simple back-and-forth pattern. But because the Earth rotates, circulating air is deflected. Instead of circulating in a straight pattern, the air deflects toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere, resulting in curved paths. This deflection is called the Coriolis effect. It is named after the French mathematician Gaspard Gustave de Coriolis (1792-1843), who studied the transfer of energy in rotating systems like waterwheels. (Ross, 1995).
Global winds drag on the water’s surface, causing it to move and build up in the direction that the wind is blowing. And just as the Coriolis effect deflects winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, it also results in the deflection of major surface ocean currents to the right in the Northern Hemisphere (in a clockwise spiral) and to the left in the Southern Hemisphere (in a counter-clockwise spiral). These major spirals of ocean-circling currents are called “gyres” and occur north and south of the equator. They do not occur at the equator, where the Coriolis effect is not present (Ross, 1995). Ekman spiral The Ekman spiral, named after Swedish scientist Vagn Walfrid Ekman (1874-1954) who first theorized it in 1902, is a consequence of the Coriolis effect. When surface water molecules move by the force of the wind, they, in turn, drag deeper layers of water molecules below them. Each layer of water molecules is moved by friction from the shallower layer, and each deeper layer moves more slowly than the layer above it, until the movement ceases at a depth of about 100 meters (330 feet). Like the surface water, however, the deeper water is deflected by the Coriolis effect—to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. As a result, each successively deeper layer of water moves more slowly to the right or left, creating a spiral effect. Because the deeper layers of water move more slowly than the shallower layers, they tend to “twist around” and flow opposite to the surface current. |
Atmospheric circulation without the Coriolis effect.
Impact of the Coriolis effect.
Ekman spiral
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El Nino and La Nina
| el_nino.ppt |
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Examine the sea temperature anomalies on the following animation. How can we tell that there was an El Nino event. Recognize the evidence: NOAA sea temperatures Pacific
Case Study: 1997/1998 El Nino
Using the Geofactfile below explain what El Nino and La Nina is as well as identifying some of the impacts that it might have on the world. Make specific reference to precise events and areas (these will be needed in any essay).
Case Study: 1997/1998 El Nino
Using the Geofactfile below explain what El Nino and La Nina is as well as identifying some of the impacts that it might have on the world. Make specific reference to precise events and areas (these will be needed in any essay).
| 61_ei_nino.pdf |
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Carbon Dioxide
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The ocean dominates the earth's carbon cycle. Half the photosynthesis (primary productivity) on earth takes place in the sunlit layers of the ocean and the ocean absorbs half of all carbon dioxide added to the atmosphere.
The ocean is what we call a carbon sink - actually the largest carbon sink on earth! That means it stores carbon. How important are the oceans on regulating world carbon dioxide levels. |
Ocean Carbon Cycle
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The Value of Oceans
Resource base
The ocean is one of Earth's most valuable natural resources. It provides food in the form of fish and shellfish—about 200 billion pounds are caught each year. It's used for transportation—both travel and shipping. It provides a treasured source of recreation for humans. It is mined for minerals (salt, sand, gravel, and some manganese, copper, nickel, iron, and cobalt can be found in the deep sea) and drilled for crude oil.
The ocean plays a critical role in removing carbon from the atmosphere and providing oxygen. It regulates Earth's climate. The ocean is an increasingly important source of biomedical organisms with enormous potential for fighting disease. These are just a few examples of the importance of the ocean to life on land.
The ocean plays a critical role in removing carbon from the atmosphere and providing oxygen. It regulates Earth's climate. The ocean is an increasingly important source of biomedical organisms with enormous potential for fighting disease. These are just a few examples of the importance of the ocean to life on land.
Info-graphic on our Oceans
Fishing
Create a reports on Over fishing:
- What is over fishing?
- Where is it occurring?
- Why is it a problem?
- What things can we do to prevent it? Identify and explain a variety of methods.
How overfishing impacts the ecosystem
Global overfishing
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World fisheries and aquaculture production
Areas most at risk of overfishing
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Success of marine conservation areas in increasing fish biomass
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Case Study: Conservation Policy: Sustainable Fishing
This case study can also be used for used for Core 3 Unit: Sustainability and the Environment
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Pollution in our oceans
| pollution_in_the_oceans.ppt |
Radioactive Waste
Case Study: Fukushima |
Examples available
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Satellite image of Fukushima radiation
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Major fishing areas contaminated after Fukushima
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Waste - Plastic
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Toxic Pollution
http://see-the-sea.org/topics/pollution/toxic/ToxPol.htm#eutrophication
http://www.seaweb.org/resources/briefings/toxic.php
Mercury Pollution
http://www.seaweb.org/resources/briefings/toxic.php
Mercury Pollution
The Pollutants Entering the Oceans
Oil Pollution
Oil spills from Steven Heath
| oil_spills.ppt |
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Create a set of case study notes on the Deepwater Horizon Oil spill. |
Examples available
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Coastal Margins
This section of the unit is extremely important for your Internal Assessment.
Pay extra attention to the coastal processes, features and management strategies.
Pay extra attention to the coastal processes, features and management strategies.
How do waves interact with the coast?
Examine:
- What are waves?
- What factors affect them?
- How do they interact with the coast?
Example of depth change near a headland
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Wave refraction
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| Coastal Processes and Landforms - Revision |
Examine how cliff structure impacts cliff retreat and coastal landforms
| sand_dunes.ppt |
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Explain the concept of advancing and retreating coasts. |
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Click on the image on the left to access an animation of how sea level change will impact Europe. |
| sea-level-change-as1866.ppt |
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Management Strategies
| Coastal Conflicts - Overview |
Case Study: Holderness Coast
Using the following documents create an A3 case study report on the management of the Holderness Coast
Using the following documents create an A3 case study report on the management of the Holderness Coast
| holderness_ks4_presentation.ppt |
| outline_map_of_holderness_coast.docx |
| a141_hodderness.pdf |
Geopolitics of Oceans
Economic Exclusive Zone (EEZ)
A maritime zone adjacent to the territorial sea that may not extend beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured. Within the exclusive economic zone (EEZ), the coastal state has sovereign rights for the purpose of exploring, exploiting, conserving, and managing natural resources, both living and nonliving, of the seabed, subsoil, and the subjacent waters and, with regard to other activities, for the economic exploitation and exploration of the zone (e.g., the production of energy from the water, currents, and winds).
A maritime zone adjacent to the territorial sea that may not extend beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured. Within the exclusive economic zone (EEZ), the coastal state has sovereign rights for the purpose of exploring, exploiting, conserving, and managing natural resources, both living and nonliving, of the seabed, subsoil, and the subjacent waters and, with regard to other activities, for the economic exploitation and exploration of the zone (e.g., the production of energy from the water, currents, and winds).
EEZ and Conflict (Wikipedia links)
The exact extent of exclusive economic zones is a common source of conflicts between states over marine waters.
Extended Reading
The exact extent of exclusive economic zones is a common source of conflicts between states over marine waters.
- One well-known example of such dispute was the Cod Wars between the United Kingdom and Iceland.
- Norway and Russia dispute both territorial sea and EEZ with regard to the Svalbard archipelago as it affects Russia's EEZ due to its unique treaty status. A treaty was agreed in principle in April 2010 between the two states and subsequently ratified, resolving this demarcation dispute.[7] The agreement was signed in Murmansk on September 15, 2010.[8]
- The dispute over Rockall is mainly due to its effect on EEZ, not on its resources or strategic benefits.
- The South China Sea (and the Spratly Islands) is the site of an ongoing dispute between several neighboring nations.
- Croatia's ZERP (Ecological and Fisheries Protection Zone) in the Adriatic Sea caused friction with Italy and Slovenia, and caused problems during Croatia's accession to the European Union.
- A wedge-shaped section of the Beaufort Sea is disputed between Canada and the United States, as the area reportedly contains substantial oil reserves.
- France claims a portion of Canada's EEZ for Saint-Pierre-et-Miquelon based on a new definition of the continental shelf and EEZ between the two countries. Saint-Pierre-et-Miquelon is entirely surrounded by Canada's EEZ.
- Mauritius claims EEZ for Tromelin from France and EEZ for British Indian Ocean Territory from the UK.
- Northern Cyprus claims a portion of Cyprus' EEZ overlaps with that of Northern Cyprus in the south/southeastern part of the Cyprus island.[9]
- Cyprus claims a portion of Turkey's EEZ overlaps with its own EEZ.[10]
- Lebanon claims that the agreement between Cyprus and Israel overlapped its own EEZ.
Extended Reading
EEZ Conflicts: Case Studies
You will need to research a particular resource found in the oceans and how different countries have come into conflict over this resource. I would strongly suggest looking at Fossil fuels as this is not only one of the most sought after resources but has many examples of conflicts.
Possible regions that you could look at:
IB Essay Questions:
“With reference to a named resource examine the extent to which countries disagree over geopolitical boundaries in the world’s oceans”
You will need to research a particular resource found in the oceans and how different countries have come into conflict over this resource. I would strongly suggest looking at Fossil fuels as this is not only one of the most sought after resources but has many examples of conflicts.
Possible regions that you could look at:
- South China seas conflict (use this as your main example)
- Senkaku islands dispute
- The Barents Sea Conflict
IB Essay Questions:
“With reference to a named resource examine the extent to which countries disagree over geopolitical boundaries in the world’s oceans”
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Coral Reefs and Mangroves
Divide the class into two groups (one to look at Coral Reefs and the other to look at Mangrove Forests). Each group is to create a Presentation outlining:
Points 4-9 should also include a case study example/s
You will also need to create a Case Study hand out of no more than 2 pages long.
- What are Mangrove Forests or Coral Reefs?
- Where do they occur? (Describe their distribution)
- What conditions do they require to form?
- How are they important to the environment?
- What is their economic value (both to the country they are located in and internationally)
- How and why are they being damaged?
- What impact is this damage having on the economy and environment?
- How can we protect them?
- How successful has this been?
Points 4-9 should also include a case study example/s
You will also need to create a Case Study hand out of no more than 2 pages long.
Coral Reefs
| coral_reefs_information_pack.doc |
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Mangrove Forests
