The+History+of+Sea+Level+Changes

Your topic is past events that have changed the sea level on Earth, the causes and consequences of these events. Clarissa Enes Sara Geriak Eric Lewis Project Grade- Organization 4 /5 -Looks a bit like a bunch of indivdual thoughts stuck on a page but works. Climate change explanation 8 /10 -Effects of sea level change in past? causes (you give one) Oceanography explanation 12 /15 -Thermal expansion?! Diagram/connection to text 8 /10 -Some good diagrams (some don't work?) Could use a bit more explanation and relation to text.

====      You got the ball rolling. Now look into how has sea level changed over time. Could you find a graph of sea level over the past few million years? Why did sea level change? What effect did this have on organisms of the ocean? What do they think a sea level change might do this time? -Swanson Okay, we got the diagram (and two others that are not working?) Take a look at some of the questions and see what you can come up with for some explanations for your topic to go with them. Sea Level change is clearly a problem. A huge reason for the sea level change though is caused from human beings.We are creating the problem, and that problem is putting us in danger. Global warming has a huge affect on the changing of the sea level. The change is very significant along the U.S. coast. Because of the land subsiding, the sea level has risen 5 to 6 inches higher than the average sea level in the last century. (http://www.epa.gov/climatechange/effects/coastal/index.html) The melting of ice caps also has a huge impact on the rise of sea level. From the last ice age, the sea level raised 120 meters. Imagine what another ice age could do to the planet. The weather as well, will affect the level of the sea, because the volume of water is affected from the temperature. The average sea level change range was 1.8 mm per year for the past century. It has now increased to 2.1 mm per year. (http://en.wikipedia.org/wiki/Sea_level_rise) media type="youtube" key="bffp7Sr5IBc" height="344" width="425" Melting ice bring changes to freshwater resource and wildlife habitat. Sea water occur due to warming ocean temperature. The last time the sea level change it was higher and the sea level change it was 4-6 metres higher at the time the arctic was 3-5 degrees hotter. Increasing acidity can make life diffcult for the corals and other marine organisms. Scientists fear that it will slow the growth of these organisms and cause calicum carbonate structure to dissolve. Source: www.nasa.gov (http://www.nasa.gov/vision/earth/environment/sealevel_multimedia.html) The Chart above shows the change in sea level through the past few decades due to ocean warming. Rising temperatures causes ice/glaciers to melt, which causes the sea level to rise. Sea levels can also rise due to shifts in surface plates. A shift in Surface plates can also cause the rock's mineral-makeup to change, and thus affect the survival of marine animals. It is thought that rising sea levels have been somewhat responsible to mass extinctions in the past. "//different marine groups have strong affinities for contrasting habitats — Paleozoic animals prefer calcium-rich limestone, whereas “modern�? critters opt for sandy, erosive sediments. Because limestone is more common when sea levels rise and sandstone is more common when sea levels drop, Peters concluded that historical changes in water levels altered the sea floor. This caused drastic die-offs in the marine communities.//" -[|ELIE DOLGIN] As rising/falling sea levels affect the minerals in the ocean, certain species who rely on the minerals rise and fall as well. Species that rely on one mineral that becomes rare will also become rare, and they may even become extinct. Species that rely on another mineral that becomes common will also become more common. In today's world, sea levels seem to be rising in a very quick rate. The sea level has risen about 15mm from 1990 to 2000 alone (above graph) -which is believed to be caused by climate change- and it is predicted that sea levels will rise another 10-15 inches by 2025. Rising sea levels could pose many more problems (to humans) than in past changes because of the way humans live. Encroaching salt water could contaminate groundwater and landfills, and the the rising oceans could increase pollution, coastal erosion, and it could also threaten man-made creations such as bridges and docks. This is especially dangerous when you consider that many people prefer to live near coasts - about 75% of Americans live within 50 miles of coastal areas. ([|Ken Oberrecht])====