Sea level

The Great Wave Off Kanagawa, a wood cut by Katsushika Hokusai (1760-1849).

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  • Observed Changes in Sea Level Featured Article Observed Changes in Sea Level Observed Changes in Sea Level

    Global sea levels rise and fall depending on the volume of the ocean basins versus that of the water in them. Changes in the volume of ocean basins occur over millions of years... More »

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Sea Level Rise and Coastal Flooding Impacts Viewer Last Updated on 2012-07-25 00:00:00 Sea Level Rise and Coastal Flooding Impacts Viewer Being able to visualize potential impacts from sea level rise is a powerful teaching and planning tool, and the Sea Level Rise Viewer brings this capability to coastal communities. A slider bar is used to show how various levels of sea level rise will impact coastal communities. Completed areas include Mississippi, Alabama, Texas, Florida, and Georgia, with additional coastal counties to be added in the near future. Visuals and the accompanying data and information cover sea level rise inundation, uncertainty, flood frequency, marsh impacts, and socioeconomics. Features of the Sea Level Rise Viewer include: Displaying potential future sea levels Providing simulations of sea level rise at local landmarks Communicating the spatial uncertainty of mapped sea levels Modeling potential marsh migration due... More »
Greenland glaciers and rising sea level Last Updated on 2012-05-08 00:00:00 Researchers determine that although glaciers continue to increase in velocity, the rate at which they can dump ice into the ocean is limited. Analysis of Speed of Greenland Glaciers Gives New Insight for Rising Sea Level Changes in the speed that ice travels in more than 200 outlet glaciers indicates that Greenland's contribution to rising sea level in the 21st century could be significantly less than the upper limits some scientists thought possible. The finding comes from a paper funded by the National Science Foundation (NSF) and NASA and published in the May 4, 2012, issue of the journal Science. While the study indicates that a melting Greenland's contributions to rising sea levels could be less than expected, researchers concede that more work needs to be done before any definitive trend can be identified. Studies like this one are designed to examine... More »
Module: Recent Climate Change Last Updated on 2011-08-04 00:00:00 Summary   This is a data-driven module designed to address key questions about the stability of the Earth’s climate in the past and the factors that drive climate change. This information is essential for students who want to study current climate change using NASA data, and interprets this in a correct historical context Goals   ·       Students will investigate how land surface and ocean surface temperatures have changed since 1840. ·       This exercise asks students to consider two contrasting interpretations of climate change over the last 2,000 years. ·       Both interpretations use a range of proxy data, but the Loehle data specifically excludes tree ring data. Investigate how the level of CO2 level in the... More »
Observed Changes in Sea Level Last Updated on 2010-12-16 00:00:00 Global sea levels rise and fall depending on the volume of the ocean basins versus that of the water in them. Changes in the volume of ocean basins occur over millions of years and are not directly responsive to climate, whereas changes in water volume may occur relatively rapidly and depend on global temperatures. Temperature directly changes the volume of water in the oceans. When ice melts to a liquid at 0°C, water decreases in volume by 9% (which is why icebergs float with about 9% of their volume above the surface), reaching a minimum at 4°C and then expands with temperature. Continental ice sheets sequester water that would otherwise be found in the oceans. In particular, the ice sheets of Antarctica and Greenland contain, respectively, about 2% and 0.2% of the water on Earth, and their accretion or attrition alters sea levels. Warmer global temperatures and the... More »