![]() Glacial changes can also have a more immediate impact on communities that rely on glaciers for their water supply, or on regions susceptible to floods, avalanches, or landslides triggered by abrupt glacial melt. Tracking and comparing recent and historical changes in the worlds glaciers can help researchers understand global warming and its causes (such as natural fluctuations and human activities). Because glaciers are sensitive to the temperature and precipitation changes that accompany climate change, the rate of their growth or decline can serve as an indicator of regional and global climate change. In response to climate fluctuations, glaciers grow and shrink in length, width, and depth. Kargel is part of a research team thats developing an inventory of the worlds glaciers, combining current information on size and movement with historical data, maps, and photos. Receding and wasting glaciers are a telltale sign of global climate change, said Jeff Kargel, head of the Global Land Ice Measurements from Space (GLIMS) Coordination Center at the United States Geological Survey (USGS) in Flagstaff, Arizona. And in the Alps, glaciers are retreating and disappearing every year, much to the dismay of mountain climbers, tourist agencies, and environmental researchers. Half a world away on the African equator, Hemingways snows of Kilimanjaro are steadily melting and could completely disappear in the next 20 years. More than 110 glaciers have disappeared from Montanas Glacier National Park over the past 150 years, and researchers estimate that the parks remaining 37 glaciers may be gone in another 25 years. Visit the worlds high mountain ranges and youll probably see less ice and snow today than you would have a few decades ago. At the time of publication, it represented the best available science. As of August, 2013, the GLIMS Glacier Database contains approximately 70% of the contents of the RGI, by both glacier count and area.This page contains archived content and is no longer being updated. This contribution discusses the status of the GLIMS Glacier Database and the merge of RGI data into GLIMS, showing how the merge is carried out. More data from the RGI, such as from Arctic Canada and the periphery of Greenland, are expected to be merged into GLIMS as resources at NSIDC allow and as sufficient metadata can be obtained. The New Zealand outlines came from the Randolph Glacier Inventory (RGI), a data set created with the express purpose of filling the geographic gaps in GLIMS to produce a globally complete map of glaciers. These outlines had significant overlap with existing outlines in the GLIMS database, necessitating new approaches to the merging process. New sets of glacier outlines, including 12000 outlines from the Western Himalaya and 3500 outlines from New Zealand, have recently been merged into GLIMS. Otherwise, outlines that are supposed to pertain to the same glacier will appear to be different glaciers, causing errors in summary statistics of the database, such as glacier count or area. As new glacier outlines are produced for glaciers which have already been mapped within GLIMS, we must ensure that each new outline is assigned the same GLIMS glacier ID as its previous outline. GLIMS is one of the most popular data sets at NSIDC, and a web-based map interface and web map services allow users to obtain the data at no cost. The Global Land Ice Measurements from Space (GLIMS) glacier database was built at the National Snow and Ice Data Center (NSIDC) in 2005, and now contains outlines and metadata for 120,000 glaciers.
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