How much of Antarctica is covered by ice? Its kind of like a bank accountwhen youve withdrawn all the water, there isnt any more, said Kargel. Historical data, as well as periodic reports andmeasurements of the reference glaciers, are availableat: https://alaska.usgs.gov/products/data.php?dataid=79 and https://wgms.ch. These fourglaciers were chosen because they have been studied extensively for many years and because they are thought to be representative of other glaciers nearby. The figure below, from NASA, shows the glacier extent in 1986. mass balance Baker has begun to . The Cryosphere 7, 141-151, (2013). Digital IDs were given to residents in East Palestine, Ohio, to track long term health problems like difficulty breathing before the Feb. 3 train derailment. For consistency, measurements are . A recent Facebook post seems to play on that film title with a claim about glaciers. 3 Kargel, J. S. et al. greenland Retreat of southeastern Alaska's Muir Glacier between August 1941 and August 2004. Glaciers are. (USGS), there were eighteen glaciers atop Mount Kenya in 1900, and by 1986 only eleven remained. "Today, only 130,000 remain.". Iceland However, this is a misleading statement, according to three experts who spoke to Reuters, as glaciers tend to split into several smaller glaciers when they melt - and the exact number of glaciers in 1948 is not known. The research about glaciers tells us about their physics and chemistry, but it doesnt tell us what happens to people as they melt. While current melting trends cant be slowed or reversed, the information collected through the GLIMS project will enable researchers to better understand the relationship between climate and glaciers, and to better predict areas of future glacier changes. It is not burdened by ideology and carries no political baggage as it crosses the threshold from solid to liquid. Between ad 1690 and 1710 the Vatnajokull outlet glaciers advanced rapidly. www.ipcc.ch/report/ar5/wg1. This project was funded in part by the USGS Climate and Landuse Change Research and Development Program. What percent of freshwater is in glaciers? In order for all of us to realistically move forward with needed mitigation, adaptation and transformation strategies to engage with our world and to get diverse peoples worldwide to understand climatic changes and participate, it is critical to begin paying attention to the nuanced stories people tell about their environments. He said glaciers in mountain ranges throughout the United States and the world have been shrinking for decades. "Awkward," wrote the Facebook account that published the post on March 11. Remote Sensing of Environment 78, 163-179, (2001). What is another name for continental glaciers? Journal of Glaciology 60, 537, (2014). Most of those glaciers were still there when the park was established in 1910. Although currently glaciers make a large contribution to global sea level rise, their total contributions are eventually limited by their relatively small area. The recently published U.S.G.S. doi:10.5066/F7HD7SRF. We can't even say for certainty how many exist today (estimates place the known glaciers at around 198,000, with up to 200,000 possible unknown ones) and we have access to satellites to help us study remote areas. At lower elevations, the "river" of ice naturally loses mass because of melting and ice breaking off and floating away (iceberg calving) if the glacier ends in a lake or the ocean. "The changes are so great with land ice, its like the poster child of climate change," Colgan said. We dont know how many glaciers there were in 1948, Ben Marzeion, a climate scientist and professor at the University of Bremen, said. Would like to have your comments about the Glaciers in the Himalayas with regard to the parameters you mentioned. Year-to-year trends vary, with some glaciers gaining mass in certain years (for example, Wolverine Glacier during the 1980s), but the measurements clearly indicate a loss of glacier mass over time. But starting in the mid-1980s, the glacier's front began retreating rapidly, and by 2019 was 12.4 miles (20 kilometers) upstream. Today, only 130,000 remain., Many others shared similar statements, including one Twitter user who suggests there are now 68,000 more glaciers in 2021 (here). Each glacier is exceptionally diverse, each fluctuating in multitudes of ways to local, regional and global environmental dynamics. Glacier-wide mass balance and compiled data inputs: USGS benchmark glaciers (ver. 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. How many glaciers are there on the Antarctic Peninsula? Maps of the glaciers in 1968surveyed by airplane by the USGScounted 83 ice-and-snow bodies with areas greater than 0.1 square kilometers. Recommendations for the compilation of glacier inventory data from digital sources. In Iceland, where Ive lived and worked for nine years, the glaciers are noticeably receding, but this does not necessarily mean theyre melting. Climate Dynamics 42, 37-58, (2014). They found that 10 had lost more than half their area over. Stewart, and T.K. All quotes delayed a minimum of 15 minutes. There are two main types of glaciers: continental glaciers and alpine glaciers. Heres why thats a big deal,", Official govt docs expose Michelle Obamas 14 year history as a man., BREAKING Trump preps Marines to stop presidential coup.. Juneau Individual glaciers also vary in their structure, flow, and response to climate. For example, while most glaciers in Glacier National Park are retreating, some are advancing. Jackson is the recipient of many grants and awards, including three US Fulbright grants and a US Fulbright Ambassadorship, and currently serves as an Arctic Expert for the National Geographic Society. Rather, the important questions center on how, and to what effect. If you continue to use this site we will assume that you are happy with it. It was 20 to 30 feet high at the edge, Dr. Fagre said. But by 2015, there were 26 remaining glaciers larger than 25 acres. So when I say a glacier has melted X amount, Im also saying climate change has altered something X amount. The total area covered by glaciers was 1.6 km 2 (0.62 sq mi) in 1900, however by the year 2000 only about 25%, . 9 How many glaciers are there in Washington State? Older Icelanders tell stories of immense destruction at the hands of surging glaciers, and they speak of feelings of safety and relief that the ice is now receding and can no longer harm them. About the Glaciers in Glacier National Park. GLIMS also compile all the mapped glacier outlines as ESRI shapefiles, which are freely downloadable by anyone from their website. The GLIMS team uses high-resolution satellite images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument and the Landsat Enhanced Thematic Mapper Plus (ETM+), archived at the Land Processes Distributed Active Archive Center (LP DAAC), to track the size and movement of glaciers. They bolster perceptions that all a glacier can be is its melt. antarctica This is a fascinating time to study and inventory the worlds glaciers because of the recent dramatic changes., I think a hundred years from now, the GLIMS effort to study the worlds glaciers will still be going strong, said Kargel. A negative mass balance indicates that a glacier has lost ice or snow. Accessed December 2020. https://alaska.usgs.gov/products/data.php?dataid=79. Now it comes only up to your shins.. How have glaciers changed over the decades? Columbia Glacier is Alaska s fastest-moving glacier. The park-wide loss of ice can have ecological effects on aquatic species by changing stream water volume, water temperature and run-off timing in the higher elevations of the park, said lead USGS scientist Dr. Daniel Fagre. ), and the two have been interacting for the entirety of human history. What is the difference between glaciers and icebergs? The time has come for new ways of telling stories about glaciers and for listening to the stories glaciers tell us. That is because there was no satellite imagery at. ", National Snow and Ice Data Center, Glaciers and climate change, visited March 29, 2019, Email interview with Jim White, interim dean, College of Arts and Sciences, University of Colorado Boulder, March 28, 2019, Email interview with Walt Meier, research scientist, National Snow and Ice Data Center, March 28, 2019, Interview with William Colgan, senior researcher, Geological Survey of Denmark and Greenland, March 29, 2019, Durham University, "The Randolph Inventory: a globally complete inventory of glaciers," 2014, Nature, "Twentieth-century contribution to sea-level rise from uncharted glaciers," Nov. 21, 2018, U.S. Geological Survey, "Retreat of glaciers in Glacier National Park," visited March 29, 2019, Science, "Argentine scientist indicted over design of glacier inventory," Dec. 5, 2017, The Nobel Prize, Al Gore Facts, visited March 29, 2019, National Oceanic and Atmospheric Administration, "Adapting to sea level rise in Miami-Dade County, Florida," visited March 29, 2019, The Washington Post, "Obama just explained what a gigaton is. How much has the Pine Island Glacier shrunk? According to research compiled by the U.S. Geological Survey (USGS), there were eighteen glaciers atop Mount Kenya in 1900, and by 1986 only eleven remained. In many areas, glaciers provide communities and ecosystems with a reliable source of streamflow and drinking water, particularly in times of extended drought and late in the summer, when seasonal snowpack has melted away. It flows through the Chugach Mountains to Prince William Sound. Last year, 2.9 million visitors came to the park. In response to climate fluctuations, glaciers grow and shrink in length, width, and depth. How many glaciers were there in 1950? Some glacier measurements have not yet been finalized for the last few years, hence the smaller number of sites. The Global Land Ice Measurements from Space (GLIMS) programme defines guidelines and rules for conducting glacier inventories3-10. What is the global volume of land ice and how is it changing? 10 Raup, B. According to research compiled by the U.S. Geological Survey (USGS), there were eighteen glaciers atop Mount Kenya in 1900, and by 1986 only eleven remained. Since we dont know how many glaciers there were in 1948, we dont know whether there are now more or fewer.. Gem Glacier is the smallest named glacier in Glacier National Park (U.S.). Today, only 130,000 remain. Ahntastic Adventures in Silicon Valley Others have . With binoculars and a map you can get a good view of Sperry Glacier's headwall from the Hidden Lake Overlook. Also, recent glacial melt has resulted in some dramatic glacial changes; for example, some large Y-shaped glaciers that are numbered and described in the older World Glacier Inventory have recently shrunk into two separate ice masses. It's impossible to say exactly how many glaciers existed in 1950. Global and Planetary Change 56, 101-110, (2007). Washington, DC This vanishing ice holds staggering consequences. Today the number of ice bodies is 25. Glaciers are dynamic. 1 Mountain glaciers 2 Valley glaciers 3 Tidewater glaciers 4 Piedmont glaciers 5 Hanging glaciers 6 Cirque glaciers 7 Ice Aprons 8 Rock Glaciers 9 Ice shelves 10 Icefields. And Ive come to realize its vital we begin understanding these deep connections between people and ice. But what qualifies as a glacier depends on who you ask. (The coastal city is vulnerable to sea level rise.). dating Glaciers carve out the surface of the Earth, leaving behind valleys and lakes. Gem is positioned at the top of a cliff, in a small area on a ledge, which means it never had much room to spread out. Together, these glaciers cover 726,000 km2. (Image by Earth Observatory Team, based on data provided by the ASTER Science Team). How much would the sea level rise if West Antarctica melted? It tells us about the mechanics of glaciers but cannot tell us much about everything else. Maycock, (eds.). This figure shows the cumulative mass balance of four U.S. reference glaciers since measurements began in the 1950s or 1960s. The multispectral scanner (MSS) of Landsat 7 and the Operational Land Imager (OLI) of Landsat 8, the most recently launched satellite, is 30 m. This means that you can only pick out individual features larger than this, but its ideal for analysing glacier size, glacier characteristics, and for mapping glacier change2. 16 Gardner, A. S. et al. in Climate Change 2013: The Physical Science Basis. They found that all regions of the world were losing mass, with the largest losses from Arctic Canada North, Alaska, coastal Greenland, the southern Andes and high-mountain Asia. I think well have some interesting data that will be publicly accessible within the coming year, said Raup. The regions currently losing mass fastest are Arctic Canada North, Alaska, and glaciers around the periphery of the Greenland Ice Sheet. We need your help. However, more data on global rates of glacier change are needed to improve these estimates of global glacier mass balance. The U.S. Geological Survey Benchmark Glacier Program provided the data for the four glaciers inFigure 2. Glaciers are profoundly entangled with people, and glaciers influence human societies as much as human societies influence glaciers. Your email address will not be published. The Landsat programme, for example, has provided four decades of Earth imaging, meaning that we can analyse glaciers from 1972 to the present day. In total, 44% of the Worlds glacierised area is in the Arctic regions, and 18% is in the Antarctic and Subantarctic. Stocker et al.) I am a Senior Lecturer at Newcastle Univeristy, specialising in glaciology and glacial geology. Today, we have over 400,000 glaciers and ice caps scattered across Earth, over 5.8 million square miles of ice. How many glaciers are there in Washington State? Dr. Fagre noted that even under natural conditions, these small, vulnerable mountain glaciers would have lost ground over the past 50 years but they would have eventually stabilized at a reduced size. Levermann et al., 2013, argue that, over thousands of years, the Antarctic ice sheets will contribute 1.2 m of sea level rise per degree of warming. Firstly, it is problematic to suggest that a comparison between glacier numbers in 2021 and Al Gores birth could disprove climate change, three experts told Reuters. They are currently contributing about one third of currently observed sea level rise, and are more important than the Antarctic and Greenland ice sheets on decadal timescales. Land Processes DAAC How to Market Your Business with Webinars? Scientists use satellites to map glaciers and reliable satellite monitoring didnt start until the mid 1980s. What percent of Iceland is covered by glaciers? Theyre a type of natural reservoir with a temper, in some cases. Despite their comparatively small area, glaciers contribute significantly to global sea level rise1. How many canyons are in the Rocky Mountains? But, Kemp said, its not globally complete. Based on database version: doi:10.5904/wgms-fog-2019-12. The estimate of glacier volume depends strongly on the method used, and more data are urgently required to improve the uncertainties on this estimate. Glaciers are profoundly entangled with people, with individual and community lifeways and glaciers influence human societies as much as human societies influence glaciers. How much ice is melting each year in Antarctica? Cambridge, United Kingdom: Cambridge University Press. Post, A. and Portland State University. However, this is a slightly arbitrary quantity, as it depends on the quality of the digital elevation model used, mapping resolution, and the minimum-area threshold used. Historical evidence suggests that Vatnajokull was quite large by the end of the seventeenth century, causing damage to farms and pastures. The four U.S. referenceglaciers have shown an overall decline in mass balance since the 1950s and 1960s and an accelerated rate of decline in recent years (see Figure 2). Substantial evidence tells us that human-made climatic changes are to blame, and the unhappy marriage between immense ice loss and climate change has led glaciers to be increasingly recognized as one of the most visible icons of global environmental changes. The glacier formed by accumulating ice upward, becoming thicker. A .gov website belongs to an official government organization in the United States. Reuters has previously addressed instances of misinformation shared in tandem with the Glasgow event, which vary in topic from the talks themselves, to general claims about climate change (here , here , here , here and here). As Nigerian writer Chimamanda Ngozi Adichie thoughtfully observed in a TED Talk, The single story creates stereotypes, and the problem with stereotypes is not that they are untrue, but that they are incomplete. Climate change What kind of glaciers are found in Montana? There will still be glaciers to study, although far fewer than there are today. Radi et al., 2014, use the RGI to estimate global glacier volume at 405 mm sea-level equivalent (SLE) (146,949 Gt or 163,276 km3 ice)14. What are the different types of glaciers in the world? 20006, Florida Working Group I contribution to the IPCC Fifth Assessment Report. Glacier National Park is losing its glaciers. How much snow per year is there on Thwaites Glacier? As the data become available in the database, users will be able to do online searches and see the resulting data in multiple formats, including views of glacier extent and elevation superimposed on ASTER images., This composite ASTER image shows how the Gangotri Glacier terminus has retracted since 1780. Snow and Ice, Land Although these adjacent glaciers come from the same ice cap, they have different surface character because they are flowing at different rates. 1958. It wont be global coverage yet, but there should be some good snapshots of glacier health within a few regions. By mid-century, it, too, will be gone. The analogy here is, think of the shoreline where the water is shallow and the slope of the beach is flat, and we have a small drop in sea level, which immediately reveals a whole lot of beach. What do glaciers leave behind when they melt and recede? 5,000 foot elevation gain to reach a view of Sperry Glacier. During the interval between photographs, Muir Glacier ceased to have a tidewater terminus. Occasionally people are included in this story, but it is usually within the context of melt and a specific, predicted outcome that melting glaciers might entail for communities: destruction. Studies by Marzeion (here) and Vargo (here) suggest that glacier loss is largely caused by human activity affecting the climate system. 2017. A lock () or https:// means youve safely connected to the .gov website. The line on the upper graph represents the average of all the glaciers that were measured. Ice shelves The number of glaciers had not greatly increased - it was simply that they had never been systematically counted before. But I have researched glaciers for decades worldwide, and I can tell you glaciers are not just thermometers, and ice does not just melt. As glaciers are more and more iconized with climate change, everything else about a glacier seems to fall away their immense diversity and their complexity. This figure shows the cumulative change in mass balance of a set of reference glaciers worldwide beginning in 1956. How much precipitation does the Arctic tundra get? And, USGS notes, "worldwide glacial glacier recession is well documented. 4. Latitude, topography, and global and regional climate patterns are important controls on the distribution and size of these glaciers. But they retreat when melting outpaces the accumulation of new snow. An official website of the United States government. ", "Early park visitors and scientists noted that glaciers were retreating as early as 1914," according to the post. According to Colgan, we dont know what the global number of glaciers was in 1948, the year Al Gore was born. Please upgrade your browser. The GLIMS database will store detailed information for the entire outline of each glacier, providing more complete spatial data, said Bruce Raup, technical lead for the GLIMS project at NSIDC. The distribution of glacier area with altitude is important, as it means that different areas will respond to climate change in different ways. Thats also incorrect. 317-382 (Cambridge University Press, 2013). This information is part of a larger, ongoing USGS glacier study of glaciers in Montana, Alaska and Washington to document mass balance measurements that estimate whether the total amount of ice is increasing or decreasing at a particular glacier. The 2006 movie "An Inconvenient Truth," for example, follows Gore as he discusses the dangers of global warming. Vargo pointed to a 2015 paper from the World Glacier Monitoring Service (WGMS) (here), which indicated that glacial mass loss rates are "without precedent according to observations since 1850. My yes! is supported by the belief that in order for all of us and our environments to make it through this time of immense transformation, we need to begin thinking with our glaciers, our rivers, our local landscapes and our environments. All rights reserved. How many ice shelves does Greenland have? For example, glacier melt is threatening the livelihoods and lifeways of 1.5 billion people in the Himalaya region. A meme featuring a photo of Gore (here, here, here), shared tens of thousands of times on Facebook, reads: The day Al Gore was born there were 130,000 glaciers on Earth. Younger Dryas, Introduction | Remote sensing of glaciers | Glacier inventories | The Randolph Glacier Inventory | Glacier contributions to sea level rise | Summary | References | Comments |. The data for Glacier National Parks named glaciers are available at the USGS ScienceBase website. Peer-reviewed studies show both have been reducing since the 1950s (here and here). Today, as anthropogenic climatic changes intensify throughout the troposphere the layer of atmosphere where you and I live, and where climate happens I suspect that the questions of critical importance will no longer center on whether the planets glaciers are transforming. who wins student body president riverdale. Theres Hoffellsjkull, a glacier pivotal to the Icelandic history of glaciology and demonstrative of the connections between Icelanders and ice; Flajkull, which has historically released many devastating glacier floods on the community; Heinabergsjkull, a chimera glacier that is receding in a much less visible way and has propelled diverse interpretations of glacier change; Sklafellsjkull, a glacier that embodies different perceptions of livingness to the people who live near it; and Breiamerkurjkull, a glacier not visible from Hfn but that, through tourism, has had profound economic impacts on the village and region. A glacier is a large mass of snow and ice that has accumulated over many years and is present year-round. What color is the roof of your mouth supposed to be? Ice extent for every glacier in Glacier National Park in 1966 and 2015, One of the reasons we study glaciers is because they have a simple, visual and easily understood response to climate, said Daniel Fagre, a U.S.G.S. The numbers are wrong, but that's not all. Calculating glacier ice volumes and sea level equivalents, Antarctic supraglacial lakes and ice-shelf collapse, An introduction to the Greenland Ice Sheet, Glacier recession around the Greenland Ice Sheet, Supraglacial hydrology of the Greenland Ice Sheet, Plateau Icefields: Glacial geomorphology of Juneau Icefield, Dealing with uncertainty: predicting future sea level rise, Degree day models: Modelling glacier melt, A introduction to the hierarchy of ice-sheet models, Differences between Arctic and Antarctic sea ice, The role of debris cover on glacier ablation, Introduction to glaciated valley landsystems, Cirque glaciation landsystem of upland Britain, Subpolar landsystems of James Ross Island, Alpine icefield landsystem of upland Britain, Plateau icefield landsystem of upland Britain, Quantifying ice sheet thinning using cosmogenic nuclide ages, In situ 14C exposure age dating in Antarctica, Precision and accuracy in glacial geology, Ice stream initiation on the northern Antarctic Peninsula, Geophysical Surveys: The Gamburtsev Mountains, Glacial geomorphology of the Patagonian Ice Sheet, The westerly winds and the Patagonian Ice Sheet, Glaciolacustrine Landforms in Patagonia, Chile, Introduction to the Glaciation of Britain, The LGM British-Irish Ice Sheet: an introduction, Shelf-edge margins of the British-Irish Ice Sheet, Unlocking ice-flow pathways using glacial erratics, Introduction to the Glacial Landsystems of the Younger Dryas glaciation of Britain, Younger Dryas glacial moraines (Lake District), Teaching resources on the last British-Irish Ice Sheet, Post-16 education and A-Level content on AntarcticGlaciers, Deplete and Retreat: future of the Andes Water Towers, Science in Extreme Environments: Juneau Icefield, Alaska, Safety on Glaciers and Icefields: Juneau Icefield, Alaska, Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License, The Global Land Ice Measurements from Space (GLIMS). How many miles is the Antarctica Ice Shelf? Ive returned to glaciers Ive researched for years to find them unrecognizable and withered, and this breaks me. Multispectral imaging contributions to global land ice measurements from space. Years ago, Canadian anthropologist Julie Cruikshank asked, after decades researching indigenous people and glaciers in Alaska and Western Canada, if glaciers were good to think with.. Mountain glaciers. (You can see photos showing how the Shepard Glacier in the park has changed from 1913 to 2005.). Marzeion directed Reuters to the Randolph Glacier inventory (www.glims.org/RGI/), the first estimate of how many glaciers exist, initially published in 2012. Title graphic image: South Cascade Glacier in the Washington Cascade Mountains, in 1928, 1979, and 2000 (Images courtesy of the National Snow and Ice Data Center). In the United States, glaciers can be found in the Rocky Mountains, the Sierra Nevada, the Cascades, and throughout Alaska. Get access to this video and our entire Q&A library, Global Warming: Atmospheric Causes and Effect on Climate. After the end of the Little Ice Age, glaciers across the Western United States, Canada and Europe lost ice as temperatures rebounded. Deplete and Retreat Publications and Outputs, An introduction to the Physical Geography of Antarctica StoryMap, Not so humbly Humboldt: the queer relationships of a German explorer. Wikipedia lists over 500 of named glaciers. The mapped measurements of glaciers complement ground surveys of glaciers using GPS along with repeat photography that involves re-photographing historic photos of glaciers taken early last century when there were an estimated 150 glaciers larger than 25 acres in Glacier National Park. A glacier flows naturally like a river, only much more slowly. As glaciologist Helgi Bjrnsson wrote, Nowhere in Iceland has the proximity and relationship between man and glacier and its rivers been so intimate and difficult than along the coastline south of Vatnajkull. A local man told me, My father used to sweep the glacier from his door each morning.. And in the Alps, glaciers are retreating and disappearing every year, much to the dismay of mountain climbers, tourist agencies, and environmental researchers. How many waterfalls are in the Rocky Mountains? Scientists collect detailed measurements to determine glacier mass balance, which is the net gain or loss of snow and ice over the course of the year. Just as no two people in the world are ever the same, neither are two glaciers. In context, that means that by 2100 AD, about half of all the Worlds glaciers will be gone unless strong mitigation strategies are employed. USGS (U.S. Geological Survey). That's how much ice Earth's glaciers lost in the 55 years between 1961 and 2016. Hibbard, D.J. 1. A .gov website belongs to an official government organization in the United States. It ensures that inventories carried out in different places by different people are comparable. Romain Hugonnet, a research assistant and PhD student at the Laboratory of Space Geophysical and Oceanographic Studies (LEGOS), University of Toulouse, said a more accurate climate change indicator would be a measurement of the surface or volume of glaciers. how many glaciers were there in 1948 how many glaciers were there in 1948. google mountain view charge cash app; wect news bladen county; how many glaciers were there in 1948; how many glaciers were there in 1948. danville jail mugshots; marlin 1898 stock; 39 miles hunan impression . That technology did not exist in 1950. From the RGI, we can learn that there are 198,000 glaciers in the World. Sources: Post, 1958;2Nolan, 20033Web update: August2016. WAIS Former vice president Al Gore has used his celebrity to try to curb the worst consequences of climate change. Our experts can answer your tough homework and study questions. The data include scientific information for the 37 named glaciers in Glacier National Park and two glaciers on U.S. Forest Service land. For consistency, measurements are in meters of water equivalent, which represent changes in the average thickness of a glacier. We use cookies to ensure that we give you the best experience on our website. How many cinder cone volcanoes are there in the world? While the shrinkage in Montana is more severe than some other places in the U.S., it is in line with trends that have been happening on a global scale, Fountain said. This indicator describes the change in glacier mass balance, which is measured as the average change in thickness across the surface of a glacier. Share sensitive information only on official, secure websites. Web update: August 2016. Today there are 198,000 glaciers.. Reston, VA 20192 Previous glacier databases stored information such as location, length, orientation, type, and altitude for one point near the center of each glacier.