William Bidlake, Hydrologist (wbidlake@usgs.gov) Measurements began on South Cascade Glacier, WA in 1958, expanding to Gulkana and Wolverine glaciers, AK in 1966, and later Sperry Glacier, MT in 2005. The opposite trends for these two maritime glaciers were the result of a shift in the winter storm tracks coming from the northeast Pacific Ocean. The mean annual balance from 1984 to 2009 on North Cascade glaciers is −0.51 m/y ().The cumulative balance is −13.26 m, equal to an ice thickness loss of nearly 15 m ().This is comparable to the mean annual balance on South Cascade Glacier of −0.78 m/y (Bidlake et al., 2007). Accessibility Start studying Case Study of Glacier Retreat: South Cascade Glacier, USA. A third way to explore the mass balance history of these three glaciers is by examining mass turnover, which describes the amount of water moving through the glacier system and the intensity of the local hydrologic cycle. Densities of snow and ice differ considerably and before glacier-average thickness changes in each material can be summed to the net balance, the changes must be converted to a common basis. /fs/2009/3046/index.html South Cascade Glacier located in a north-northwest facing valley near the crest of the Cascade Range in northwest Washington state. The USGS has been monitoring the mass balance of three glaciers in the Pacific Northwest and in Alaska for nearly 50 years. South Cascade Glacier (lat 48°22' N., long 121°03' W., fig. Pelto's research team has recorded the mass balance of numerous glaciers, all of which are retreating due to global warming, which has raised temperatures; which in turn has increased melting and increased the frequency of winter rain and melt events that reduce winter accumulation on North Cascade glaciers. It spans 1300 m of elevation, from 1160 to 2470 m. The glacier is in a 31.5 km 2 basin and in 2016 it had an area of 16.0 km 2 (O'Neel et al, 2019). 2). All three glaciers have lost mass since USGS monitoring began more than four decades ago. A shrinking glacier thins faster near the terminus (the lowest part of the glacier) than near the head (the highest part of the glacier), which is why the terminus retreats up-valley while the glacier head remains in place (fig. Photos courtesy USGS. These stake measurements, along with local temperature and precipitation data, allow USGS scientists to estimate the glacier net balance, as well as the seasonal winter (total accumulation) and summer (total ablation) balances that sum to the net balance. Figure 4. By looking at this photo it's clear to see how quickly the glaciers are retreating in the modern world. 1928 to 2000 comparison: These photos of the South Cascade Glacier in the Washington Cascade Mountains show dramatic retreat between 1928 and 2000. Meier, M.F., Tangborn, W.V., Mayo, L.R., and Post, A., 1971, Combined ice and water balances of Gulkana and Wolverine Glaciers, Alaska, and South Cascade Glacier, Washington, 1965 and 1966 Hydrologic Years: U.S. Geological Survey Professional Paper 715-A, 23 p., 4 pl. URL: http:// Since 1989, the cumulative net balances of all three glaciers show trends of rapid and sustained mass loss. Time series of winter balance (net accumulation—blue), summer balance (net ablation—red), and net balance (yellow) for the three benchmark glaciers (Josberger and others, 2007). The cumulative net balance is the total loss or gain of glacier mass since the beginning of the study period and is presented as spatially averaged thickness change (fig. pubs.usgs.gov The glacier is located at the head of the Cascade River, which drains into the Skagit River and Puget Sound. South Cascade glacier shows alarming rate of melt The world's melting glaciers Glaciers around the world are retreating at unprecedented rates as temperatures rise due to climate change. The researchers also compare the satellite images with historical maps and information to determine a glacier’s advance or retreat over the past few decades. Note how far the glacier has retreated since the 1965 photo below. Figure 7. Mass turnover of the three benchmark glaciers. During climate changes, coastal glaciers are more sensitive to changes in precipitation (or the storm tracks that bring precipitation), whereas interior glaciers are more sensitive to changes in temperature. Mass loss has accelerated during the last 15 years, coincident with the highest melt years on record. Wolverine Glacier since 1966 Lemon Creek Glacier since 193 South Cascade Glacier since 198. A glacier that is out of balance with the current climate will grow (advance) or shrink (retreat) depending on how the climate is changing (colder or wetter climate will cause advance, warmer or drier climate will cause retreat). Glaciers in continental or interior climates (for example, Gulkana Glacier) exist primarily because cold temperatures result in low ablation. Glaciers that terminate in a lake or the ocean also lose mass through iceberg calving. 2007-5055:70. Meltwater from the glacier flows directly into South Cascade Lake, which feeds the South Fork Cascade River, which is a tributary of the Skagit River. The cumulative net mass balance describes long-term trends in the glacier shape and size, that is, whether the glacier is growing or shrinking. It is bordered on the east by 8,261-foot (2,518 m) Sentinel Peak, and is about 17 mi (27 km) north of Glacier Peak in the Glacier Peak Wilderness. Figure 2 shows trends for three “benchmark” glaciers: South Cascade Glacier in Washington state, Wolverine Glacier near Alaska’s southern coast, and Gulkana Glacier in Alaska’s interior. Melting increased over past 20 years -> glacier shrinks and retreats uphill (melting happens fastest at the snout than at the head); bigger reductions since 2005. Despite increasingly negative summer balances in the 1980s and 1990s, South Cascade Glacier did have a few years of positive mass balance; the most significant occurred in 1999, following the record 1998–99 winter snowfall. Anchorage, AK 99508. Edward Josberger, Research Oceanographer (ejosberg@usgs.gov) 3400 Shell Street The main trunk of the glacier has a southerly aspect, and is fed by four cirques with west, south, and east aspects. Glacier retreat in Glacier National Park, Montana, U.S.A., is one example of land ice loss and glacier change. The well-studied South Cascade Glacier shrank by 22% during this time period (USGS), while the Blue Glacier in Olympic National Park saw a terminus retreat of 2% between 1957 and 1997 (Conway et al., 1999). The USGS measures accumulation and ablation using a network of stakes distributed over the glacier (fig. 6) resulting from record high temperatures and low precipitation, also set the stage for large, intense wildfires that burned in Alaska. To see if a glacier is growing or shrinking, glaciologists check the condition of snow and ice at several locations on the glacier at the end of the melt season. The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use, mountain recreation, animals and plants that depend on glacier-melt, and, in the longer term, the level of the … Mass turnover has increased throughout monitoring and the trend of increase has become stronger during the last two decades. At the same time that South Cascade Glacier was gaining mass in the early 1970s, Wolverine Glacier was losing mass. What have we learned so far? Photos courtesy USGS. Since the late 1950s, the USGS has maintained a long-term glacier mass-balance program at three North American glaciers. The net balance is the average mass balance over the entire glacier for one glaciological year, the time between the end of the summer ablation season from one year to the next. The net balance of Wolverine Glacier (yellow bars) tracks the winter balance (blue bars) more closely than the summer balance (red bars), in accordance with its location in a coastal climate. A glacier that is in balance with the current climate will have zero net balance and a steady size. The 50-year mass balance records for these three USGS Benchmark Glaciers show annual and interannual fluctuations that reflect the controlling climatic conditions. The glacier retreat was slow up to 1987 a total of 25 m. By 2015 the total retreat has amounted to 520 m. The lower section of the glacier below the lowest icefall is stagnant and will be lost. Page Last Modified: Tuesday, 29-Nov-2016 17:33:37 EST, Download the latest version of Adobe Reader, free of charge. In its warm phase, the PDO tends to be associated with more northerly storm tracks, which in the past provided moisture for the growth of Wolverine Glacier at the expense of South Cascade Glacier. 6) can reveal whether variations in temperature or precipitation are primary factors for observed changes. This valley glacier occupies roughly one-half of a 6.11-km 2 basin. The most direct way to quantitatively observe changes in a glacier is to measure its mass balance: the difference between the amount of snowfall, or accumulation, on the glacier, and the amount of snow and ice that melts and runs off or is lost as icebergs or water vapor, collectively termed ablation (fig. USGS scientists visit each site in spring and autumn (sometimes more often) to keep a running tally of accumulation and ablation for each stake. South Cascade Glacier, October 2000. Sperry Glacier since 200. 4210 University Drive Regional climate exhibits strong control on glacier mass balance, and over decadal time scales mass balances correlate with regional climate change. CANADA. One interpretation of the trend towards increasing summer melt at the Benchmark Glaciers is that climate changes that are larger in scale and intensity than periodic shifts in ocean conditions (PDO) are underway. Mass balance of the coastal South Cascade and Wolverine Glaciers correlate well with the PDO during the first few decades of the period of record, showing the effects of ocean-condition periodicity on glacier health. 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) Scientists track glacial change by measuring individual glaciers and comparing their size over time with records of … This synchronous decline could be the result of recent climate changes that are stronger than the PDO-induced variations of the earlier periods of record. Retreat of South Cascade Glacier, Washington, during the 20th Century The results confirm stake measurements at South Cascade Glacier in the North Cascades, showing significant loss over the past 60 years. Today, the federal benchmark glacier program extends beyond Alaska and includes research at the South Cascade Glacier in Washington state and the Sperry Glacier in Montana. This change, when coupled with a reduction in accumulation (thin snowpacks), has resulted in very negative net balances. Four less active glaciers (Lynch, White Chuck, South Cascade, and "Banded") have continued to retreat, and six stagnant, relict ice masses have undergone considerable losses. Josberger, E.G., Bidlake, W.R., March, R.S., and Kennedy, B.W., 2007, Glacier mass-balance fluctuations in the Pacific Northwest and Alaska, USA: Annals of Glaciology, v. 46, p. 291-296. A qualitative method for observing these changes is through repeat photography—taking photographs from the same position through time (fig. The project has grown steadily since then to include more glaciers every year. and the beginning of the 21st Century. Mountain glaciers occur on all continents except Australia. Play media. These long periods of record provide clues to the climate shifts that may be driving glacier change. CS1 maint: multiple names: authors list (, https://en.wikipedia.org/w/index.php?title=South_Cascade_Glacier&oldid=754096807, Creative Commons Attribution-ShareAlike License, This page was last edited on 10 December 2016, at 21:10. At the same time that South Cascade Glacier was gaining mass in the early 1970s, Wolverine Glacier … For example, several years of unusually high snowfall during the late 1970s and early 1980s caused the subsequent growth of Wolverine Glacier. U.S. Geological Survey Figure 3. Despite drought conditions, the warm weather caused excessive melting of glaciers in Alaska and consequent flooding of many glacier-fed rivers. Since higher elevations are cooler, the disappearance of the lowest portion of the glacier reduces overall ablation, thereby ... South Cascade Easton. This study documents historic BC and dust deposition as well as their effect on albedo on South Cascade Glacier (SCG) in Washington State (USA) through the analysis of a 158‐m (139.5‐m water equivalent [w.e.]) Meltwater from the glacier flows directly into South Cascade Lake, which feeds the South Fork Cascade River, which is a tributary of the Skagit River. The net mass balance of a glacier is the difference between the mass gain through accumulation of snow and the mass loss through ablation. The cumulative balance trend for North Cascade glaciers indicates an increasing trend of negative mass balance. This correlation has weakened during the last two decades, as global average temperature has increased. By custom, the common basis is "meters water equivalent" (MWEQ), which is the thickness of water that would result from melting a given thickness of snow or ice. The USGS Benchmark Glacier Program began in 1957 as a result of research efforts during the International Geophysical Year (Meier and others, 1971). 3) is located in the North Cascades of Washington. Download the latest version of Adobe Reader, free of charge. On the other hand, seasonal balances (fig. The least significant retreats among the glaciers studied were for Rabots Glacier in northern Sweden, and South Cascade Glacier in Washington state, with probabilities of 11 and 6 … This was prompted by the National Academy of Sciences listing this as a high priority and a personal … Glaciers in coastal, maritime locations (such as Wolverine Glacier) exist primarily because of high snowfall rates, despite warm low-elevation temperatures. The South Cascade Glacier has been closely monitored by glaciologists studying the effects of climate on glaciers. South Cascade Glacier is a large alpine glacier in the North Cascades of Washington, USA. This shift most likely was due to a shift in the phase of the Pacific Decadal Oscillation (PDO), which is an ocean-climate oscillation (similar to the El Niño Southern Oscillation) in which the pattern of ocean surface temperatures and atmospheric pressures in the North Pacific Ocean oscillates on about a multi-decadal timescale. In accordance with these concepts, figure 7 shows that higher turnover rates occur at South Cascade and Wolverine Glaciers than at Gulkana Glacier. 5). Data for South Cascade Glacier are available beginning in 1959 (relative to conditions in 1958) and for Gulkana and Wolverine Glaciers beginning in 1966 (relative to conditions in 1965). Fairbanks, AK 99701, Shad O’Neel, Glaciologist (soneel@usgs.gov) [2] It is bordered on the east by 8,261-foot (2,518 m) Sentinel Peak, and is about 17 mi (27 km) north of Glacier Peak in the Glacier Peak Wilderness. Policies and Notices, U.S. Department of the Interior | Privacy Part 1 Glacial “retreat" You will be working with data from South Cascade Glacier, WA, which has been monitored in detail by the USGS since 1959. South Cascade Glacier is a large alpine glacier in the North Cascades of Washington, USA. The USGS Benchmark Glaciers each exhibit a long-term trend of increasing mass turnover, which have become more well-defined and stronger from 1985 to 2005. U.S. Geological Survey, Alaska Science Center The PDO cold phase tends to be associated with more southerly storm tracks directed at the Washington coast; South Cascade Glacier has tended to gain mass from this moisture at the expense of Wolverine Glacier. Evidence of retreat 1) USGS periodically measure South Cascade Glacier using photographic surveys and measurement stakes (take the same photo over a period of time to observe the changes) Gulkana Glacier since 1966. Glaciers average changes in climate over space and time and provide a picture of climate trends in remote mountainous regions. This mass balance record is now sufficient to interpret glacier responses to short- and long-term climate changes in the Pacific Northwest, the Alaska Coast, and the Alaska interior. Page Contact Information: GS Pubs Web Contact Glacier Cumulative Annual Balance: The negative trend has This kind of retreating is the result of climate change which has significantly increased due to … Dominated by a maritime climate, the glacier receives heavy annual precipitation, exceeding 4.5 m in places ( PRISM Climate Group, 2006 ) and is heavily influenced by climate conditions in the Pacific Ocean ( Walters and Meier, 1989 ). 4). Between 1958 and 2009 South Cascade Glacier lost nearly a half of its volume.[3]. U.S. Geological Survey, Alaska Science Center Glaciers respond to climate changes by thickening and advancing down-valley towards warmer lower altitudes or by thinning and retreating up-valley to higher altitudes. The mean ELA is 1,900 m. Water from the basin flows into the Cascade River then the Skagit River. Conversely, the net balance of Gulkana Glacier is best correlated with summer balance as expected because of the drier, continental climate of interior Alaska. Diagram of a glacier showing components of mass balance. South Cascade Glacier lost mass at an almost constant rate during the late 1950s to the late 1960s, then gained mass until 1976, and has been losing mass at a fairly constant and rapid rate since 1977. Abstract U.S. Geological Survey, Washington Water Science Center Large mass turnover is typical of coastal, maritime glaciers where winter precipitation and snow accumulation are large. Fifty years of U.S. Geological Survey (USGS) research on glacier change shows recent dramatic shrinkage of glaciers in three climatic regions of the United States. (5-year Cumulative net balance of South Cascade, Wolverine, and Gulkana Glaciers (Josberger and others, 2007). The first such map of a Mount St. Helens glacier was obtained in 2012, and the first for Mount Rainier in 2014. South Cascade Glacier lost mass at an almost constant rate during the late 1950s to the late 1960s, then gained mass until 1976, and has been losing mass at a fairly constant and rapid rate since 1977. Figure 2. Gulkana Glacier is inland and relatively isolated from maritime influences; therefore, the glacier has not responded distinctively to shifts in the PDO and to positions of winter storm tracks. Snowy winters would have to occur much more frequently in the future to reduce or reverse mass loss from the glacier. N. 0 400 800 KILOMETERS 0 400 800 MILES. This is exemplified by 2004, when strongly negative summer balances (fig. The retreat of … Figure 5. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The least significant retreats among the glaciers studied were for Rabots Glacier in northern Sweden, and South Cascade Glacier in Washington state, with probabilities of 11 and 6 percent, respectively, that their retreats might be natural variability. The North Cascade Glacier Climate Project (NCGCP) was founded in 1983 to identify the response of North Cascade glaciers to regional climate change, particularly changes in mass balance, glacier runoff and terminus behavior. Annual data collection occurs at three glaciers that represent three climatic regions in the United States: South Cascade Glacier in the Cascade Mountains of Washington State; Wolverine Glacier on the Kenai Peninsula near Anchorage, Alaska; and Gulkana Glacier in the interior of Alaska (fig. Conversely, sustained periods of negative mass balance, where accumulation is less than ablation, results in glacier shrinkage. 1). Currently, the volume of land ice on Earth is decreasing, driving consequential changes to global sea level and local stream habitat. “South Cascade is at the end of the Pacific storm track, and it experiences a high degree of wintertime variability. This has led to the retreat of all 47 glaciers we monitor, with four of those glaciers having disappeared. FOIA PACIFIC OCEAN. 934 Broadway, Suite 300 Canada WA Pacific Ocean Cascade Range South Cascade Glacier Seattle 50 100 200 km The map below shows the extent of the glacier in 1958 and in 2013. UNITED STATES UNITED STATES. The accelerating loss of mass, the weakening correlation with the PDO, and increasing mass turnover likely are the result of changes to warmer and (or) drier climate conditions that are affecting all three regions. Figure 6 shows the strong influence of regional climate. The U.S. Geological Survey monitors only four of our nation’s glaciers on an annual basis, two of which are in the Lower 48: South Cascade Glacier in Washington and Sperry Glacier in Montana. The glacier retreated 1.9 kilometres (1.2 mi) in 33 years. 3). South Cascade Glacier in Washington documented from 1928 to 2003 showing the recent rapid glacier retreating. moving averages are plotted as lines). Mass turnover is estimated by averaging the absolute values of winter and summer balances. Positive mass balance occurs when accumulation is greater than ablation and if maintained over long periods results in glacier growth. U.S. Geological Survey Scientific Investigations Report. ice core extracted in 1994 and spanning the period 1840–1991. Setting a measurement stake at South Cascade Glacier, Washington. For all three glaciers, the summer balance records show that consistently more ablation took place during the period from 1987 to 2004 than did prior to 1987. 2). Water, Ice, and Meteorological Measurements at South Cascade Glacier, Washington, Balance Years 2004 and 2005. The glacier advanced m more than any other on Mount Baker by 1975. With low total snowfall, glaciers in these areas melt before they extend far down valley. Aside from the last two groups, most of the glaciers of the North Cascades appear to have been in equilibrium with climatic conditions during the past decades. (Josberger and others, 2007). Glaciers gain mass through snowfall and lose mass through melting and sublimation (when water evaporates directly from solid ice). In drier climates, such as the Rocky Mountains or interior Alaska, glaciers typically have relatively small mass turnover. G lacier monitoring methodology has evolved over time based on scientific reanalysis, and cumulative net mass balance Excessive melting of glaciers is our region 's way of tracking the rapid advance of global warming storm,. 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