Glims definition11/6/2023 ![]() The Randolph Glacier inventory is not currently accessible through NSIDC but is available from the GLIMS project website. It includes detailed outlines of the extent of each glacier, with images in the inventory spanning from 1999 to 2010. The Randolph Glacier Inventory, which is a global catalogue of glacier outlines, supplements GLIMS Glacier Database. The GLIMS Glacier Database enables scientists to map how glaciers have changed over time, allowing them to better understand the impacts these changes will have on water resources, downstream hazards, ecosystem changes, and global sea level rise. Since its inception, over 60 institutions in 28 nations worldwide have contributed to the GLIMS Glacier Database.īecause glaciers advance and retreat in response to environmental cues, including changes in temperature and precipitation, they are strong indicators of climate change. It is a collection of worldwide cooperative networks (Regional Centers) that map and analyze glacier fluctuations in their geographic region of expertise. The GLIMS initiative was established in 1999 by the joint U.S./Japan ASTER Science Team. These additional sources include other satellite observations, such as observations from Satellite Pour l’Observation de la Terre (SPOT) and EMI+, as well as maps, aerial photographs, and historical observations dating back to 1850.Ī sample image of Alaskan glaciers from the GLIMS glacier viewer application. Data are primarily derived from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument aboard the Terra satellite and the Landsat Enhanced Thematic Mapper Plus (ETM+), but other sources are also used. The collection includes data from approximately 70 percent of the world's 200,000 glaciers, and new glaciers are continually added. The glacier database includes measurements of glacier geometry, glacier area, snowlines, supraglacial lakes and rock debris, and other glacial attributes, as well as browse images. This data collection’s primary data product is the GLIMS Glacier Database. ![]() GLIMS is an international project to inventory the world’s glaciers and to create a comprehensive, global database of land ice through repeat surveys. The NSIDC DAAC GLIMS data collection includes data from the Global Land Ice Measurements from Space (GLIMS) initiative. Exchange for Observations and Local Knowledge of the Arctic (ELOKA).NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC).Greenland Today & Antarctic Ice Sheet Today.This should facilitate a more consistent approach to identifying and mapping very small glaciers on high-resolution imagery, helping to produce more comprehensive and accurate glacier inventories. For these cases, we develop a set of criteria to enable the identification of very small glaciers and classify them as certain, probable or possible. However, when mapping on high-resolution imagery (<1 m) with minimal seasonal snow cover, glaciers <0.05 km2 and even <0.01 km2 are readily identifiable and using a minimum threshold may be inappropriate. Based on this analysis, we support the use of a minimum size-threshold of 0.01 km2 for imagery with coarse to medium spatial resolution (30–10 m). Here, we compare the ability of different remote-sensing approaches to identify and map very small glaciers on imagery of varying spatial resolutions (30–0.25 m) and investigate how operator subjectivity influences the results. For this reason, most scientists implement minimum size-thresholds (typically 0.01–0.05 km2). Historically, mapping very small glaciers (generally considered to be <0.5 km2) using satellite imagery has often been subjective due to the difficulty in differentiating them from perennial snowpatches. Small mountain glaciers are an important part of the cryosphere and tend to respond rapidly to climate warming.
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