Loss of land-based ice, like on Antarctica, is one of the driving factors behind sea level rise
Climate is the driver of sea level change. The Earth has alternated between Glacial and Interglacial Periods for millions of years. During a Glacial Period, or Ice Age, much of the water on Earth is trapped in ice sheets and, consequently, sea level drops. Interglacial Periods, on the other hand, are times of warmer temperatures which cause ice sheets to melt. When the ice becomes liquid water, it eventually finds its way to the oceans and raises the sea level. In addition, because the oceans are warmer during interglacial periods, the water expands (known as thermal expansion), which also adds to the sea level rising.
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| This animation from NOAA shows evidence of loss of ice in the North Pole. |
Sea level has steadily risen 1-2.5 millimeters a year since 1900, and it is expected to continue to rise throughout the 21st century. Although there is no perfect model to absolutely predict the future, it is possible to investigate "What If?"
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| Models based on elevation data can predict what areas could be vulnerable due to rising sea levels. |
The Department of Geosciences Environmental Studies Laboratory at the University of Arizona has a web tool that does just that. They have developed a Geographic Information System (GIS) that uses Digital Elevation Models (DEM) to show what areas are potentially vulnerable to sea level change. This web visualization, developed with ESRI's ArcViewer for Flex, allows users to set the amount of sea level rise in one meter increments with a range from no change to six meters.
