During the history of the Earth, sea levels have varied dramatically from present conditions. During the peak of the last ice age 18,000-20,000 years ago, sea level is estimated to have been about 120 meters (400 feet) lower than it is now. If the vast ice sheets covering Greenland and Antarctica were to melt completely, sea level would rise approximately 80 meters (260 feet) higher than the current value.
Today’s concerns about rising carbon dioxide concentrations in the atmosphere and the resulting warming of the world are tied closely to rises in the height of the oceans. In the past, higher atmospheric carbon dioxide levels correlated to elevated global temperatures. Temperature changes of only a few degrees have resulted in dramatic expansion and shrinkage of polar ice and glaciers, leading to pronounced sea level changes.
Sea Level Deluxe for World Wind allows you to explore the range of sea levels from distant prehistory to potential future scenarios. It is a greatly expanded version of the popular free Sea Level Standard add-on. It contains many added new features, including higher resolution, more maps, contours, flood zones and at-risk cities.
Sea Level Deluxe includes almost 3 GB of shaded relief maps of sea levels at 10 meter intervals from 80 meters above to 120 meters below the current position (1). These maps are based on the best available global bathymetry datasets and all have a maximum resolution of approximately 2 km (1.25 miles, or 1 arc min). Elevations from -11,000 to 9,000 meters (-35,000 to 30,000 feet) are displayed.
Sea Level Deluxe also displays contour lines of all the sea levels to match the relief maps at 10 meter intervals from 80 meters above to 120 meters below the current position. The contours may be combined with the relief maps and other layers or overlayed on existing World Wind image layers.
Sea Level Deluxe also provides maps of coastal flood zones for land areas 5 meters and 10 meters above present-day sea level. These masks facilitate the identification of locations that are at greatest risk of inundation by rising oceans and are susceptible to storm surges, flooding and tidal effects.
Sea Level Deluxe includes labels and a variety of icons for low-lying and coastal cities. Over half of the world’s cities with one million or more residents lie less than 80 meters above sea level. The low-lying city component contains the geographic locations and brief descriptions of these cities. They may be displayed as names, icons or flags.
A simple, high resolution political map and a set of vector-based international borders are also included for ease of use and to expand the map making options available. Sea Level Deluxe layers may be combined with the default World Wind layers, plugins and other compatible features as desired.
Visit our SeaSTA for NASA World Wind page.