Elective GEo Exam
· Distribution of oceans
· 70% of the earth’s surface is water and only 30% is land.
· Climate in the Southern Hemisphere is often more moderate than similar places in the Northern Hemisphere This is because the presence of large amounts of heat energy stored in the oceans.
· Physical Features on ocean floor
· Under the world oceans there are many things such as rugged mountains, active volcanoes, vast plateaus and almost bottomless trenches.
· Around most continents there are shallow seas that cover gently sloping areas called continental shelves. These can reach depths of 200m. The shelves end at the steeper continental slops which lead down to the deepest parts of the oceans.
- Link between Ocean current + Climate
· The worlds ocean is extremely important for heating the planet.
· The majority of the sun’s radiation is absorbed by the ocean this happens particularly in the tropical waters around the equator and the ocean acts as a massive heat retaining solar panel.
· The ocean helps distribute heat around the world when water molecules are heated they exchange freely with the air this is called evaporation.
· Ocean water is always evaporating increasing the temperature and humidity of the surrounding air to form rain and storms that are then carried by trade winds.
· Almost all rain that falls on land started in the water.
· Tropics are particularly rainy because heat absorption and as a result ocean evaporation is higher in these areas.
· Outside of the earths equatorial areas weather patterns are driven largely by the oceans currents.
· Currents are movements of the oceans water in a continuous flow.
· Major current systems typically flow clockwise in the northern hemisphere and counterclockwise in the southern hemisphere in circular patterns that often trace the coastlines.
· Ocean currents act just like a massive conveyer belt transporting warm water and precipitation from the equator towards poles and cold water from the poles back to the tropics. Without currents regional temperatures would be more extreme super-hot at the equator and frigid towards the poles and much less of earths land would be habitable.
· El Nino vs La Nina
· EL Nino
· This term refers to the large-scale ocean atmospheric climate interaction linked to a periodic warming in sea surface temperatures across the central and east central Equatorial pacific.
· Typical El Nino effects are likely to develop over North America during the upcoming winter season. Those include warmer-than-average temperatures over western and central Canada, and over the western and northern United States.
· Wetter-than-average conditions are likely over portions of the U.S. Gulf Coast and Florida while drier-than-average conditions can be expected in the Ohio Valley and the Pacific Northwest.
· The presence of El Nino can significantly influence weather patterns, ocean conditions, and marine fisheries across large portions of the globe for an extended period...