Climate Fact: Local Sea-Level Rise (Gulf Coast)
While global sea-level is rising at a rate of about 1.2 inches per decade due to an influx of glacial melt water and thermal expansion of the oceans, the relative sea-level rise or fall that each coastal location experiences is dependent on several factors. Local sea-level can rise faster than the global average due to subsidence of the land. It can rise slower than the global average or even fall if uplift of the land occurs at a sufficient pace. Along parts of Alaska’s coast, for example, sea-levels are falling as land that was pushed down by the weight of glaciers has “rebounded” as ice has melted. Changes in ocean circulation, which can shift wind and wave patterns, can also cause relative changes in sea-level. The Gulf Coast has witnessed some of the fastest rates of sea-level rise in the country. Here, 27 percent of roads, nine percent of railways and 72 percent of ports are built on land less than four feet above sea-level.
For the accompanying visual, visit http://www.earthgauge.net/climate-facts-image-library#6. This image is featured in the “Global Climate Change Impacts in the United States“report recently published by the U.S. Global Change Research Program. The image is in the public domain.
Seasons: Winter, Spring, Summer, Fall
Source: Global Climate Change Impacts in the United States, Thomas R. Karl, Jerry M. Melillo, and Thomas C. Peterson,(eds.). Cambridge University Press, 2009.
