Similar measurements began at Sperry Glacier, MT in 2005. how glacier mass balance processes impact streamflow, ultimately improving our conceptual understanding of the future evolution of glacier runoff in continental and maritime climates. This figure shows the cumulative mass balance of the three U.S. Geological Survey “benchmark” glaciers since measurements began in the 1950s or 1960s. Analyse the Glacier Mass Balance Over the whole time period, is the average annual mass balance (Ba) positive or negative? The Gulkana Glacier is one of three benchmark glaciers in the United States that the US Geological Survey have been monitoring since 1971. 2Methods 2.1 Site description The USGS began consistent measurements of glacier mass balance, streamflow and meteo-rology at Gulkana and Wolverine glaciers in 1966. Tuesday, August 3, 2010. Results from South Cascade Glacier in Washington and Gulkana and Wolverine glaciers in Alaska provide the longest continuous record of North American glacier mass balance. Examine the map of net mass balance for South Cascade Glacier in 1965. 2016). It is a polythermal glacier (Miner et al., 2018), and the mean annual mass balance during 2011–2016 was −1.6 m w. eq. Since the late 1950s, the USGS has maintained a long-term glacier mass-balance program at three North American glaciers. Mass Balance Factsheet for the Gulkana Glacier, Alaska. K. Echelmeyer, M. Stuefer, and R. Flanders were instrumental in maintaining the mass balance program on Black Rapids Glacier during the 1990s and 2000s. water balance of Gulkana and Woverine Glaciers, Alaska, and South Cascade Glacier, Washington, 1965 and 1966 water years. The “mass balance” of the Gulkana has been calculated at different times in an ongoing study about the effects of our dependence on fossil fuels and the related global warming crisis. From 1980-2008 the mean cumulative mass loss of glaciers reporting mass balance to the World Glacier Monitoring Service is -12 m. This includes 19 consecutive years of negative mass balances. West Gulkana Glacier is located in the eastern Alaska Range, only 8 km east of the Richardson Highway and Isabel Pass. Under the following links you find more information about the reference glaciers, the mass-balance datasets, and detailed assessments of global glacier mass changes.. 2 Mass balance data. Since the late 1950s, the USGS has maintained a long-term glacier mass-balance program at three North American glaciers. Camping trip to Gulkana Glacier. We reanalyzed mass balance records at Taku and Lemon Creek Glaciers to better understand the relative roles of hypsometry, local climate and dynamics as mass balance drivers. team of scientists remapped West Gulkana Glacier and determined its mass-balance changes. 2b, c) with the most notable episode occurring in the late 1970s. Vertical photographs were taken on August 31, 1967, by Austin Post and were used to redefine the margin of Gulkana Glacier and other glaciers and perennial snow fields in the basin. 3 1. [Rod March; Geological Survey (U.S.)] Systematic errors accumulate through time in this method; The net mass balance on Gulkana Glacier, Alaska, U.S.A., has been measured since 1966 by the glaciological method, in which seasonal balances are measured at three index sites and extrapolated over large areas of the glacier. C. Since the late 1950s, USGS has maintained a long-term glacier mass-balance program at three North American glaciers. Systematic errors can accumulate linearly with time in this method. Will the glacier grow, or shrink? Balance index station C (pl. eq.) The net mass balance on Gulkana Glacier has been measured since 1966 by the glaciologi-cal method, in which seasonal balances are measured at three index sites and extrapolated over large areas of the glacier. Mass balance (m w. Systematic errors can accumulate linearly with time in this method. Over the 1946–2018 period, the cumulative mass balances diverged. 3.2. 1). We derive historic ELA sensitivities to climate forcing using data from the U.S. Geological Survey (USGS) Benchmark Glacier program. The net mass balance on Gulkana Glacier, Alaska, U.S.A., has been measured since 1966 by the glaciological method, in which seasonal balances are measured at three index sites and extrapolated over large areas of the glacier. Get this from a library! For each glacier, the mass balance is set at zero for the base year of 1965. S. O'Neel is acknowledged for providing the Gulkana Glacier mass balances, M. Huss for the Black Rapids ice thicknesses, and A. Arendt for computational resources and funding. 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. It is imperative that we understand and quantify how this will affect freshwater river runoff and downstream hydrology in order to better inform local response, policy, and resource management. of the Gulkana Glacier (from USGS database) Balance Year Winter Balance Summer Balance Net Balance 1966 0.93 1.03 -0.1 In 2005, Sperry Glacier in Montana was added to the program, allowing changes in glacier mass in the principal North American climate zones to be tracked. What does this mean for the glacier?  A glacier with a sustained negative balance is out of equilibrium and will retreat, while one with a sustained positive balance is out of equilibrium and will advance. 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. Thus, the balance year beginning in September 2013 and ending in September 2014 is called “balance year 2014.” In 2005, Sperry Glacier in Montana was added to the program, allowing changes in glacier mass in the principal North American climate zones to be tracked. Results from South Cascade Glacier in Washington and Gulkana and Wolverine glaciers in Alaska provide the longest continuous record of North American glacier mass balance. Episodes of positive glacier-wide mass balance (greater than uncertainty) have modulated mass loss at Wolverine Glacier several times since the observations began (Fig. This article summarizes the findings of this survey and reports on the inferences that the data permit for three decades of regional climate. These glaciers have the longest continuous mass-balance records in North America, with winter balance Bw, summer balance Bs, and annual balance … 2.1 Mass Balance Observations. (Liljedahl et al., 2017). Gulkana Glacier is a multi-branched valley glacier located in a continental climate regime on the south flank of the eastern Alaska Range in central Alaska. Mass balance, meteorology, area altitude distribution, glacier-surface altitude, ice motion, terminus position, and runoff at Gulkana Glacier, Alaska, 1996 Balance Year. Direct field measurements are combined with weather data and imagery analyses to estimate the seasonal and annual mass balance at each glacier in both a conventional and reference surface format (Cogley and … At Gulkana Glacier, sustained negative mass balance has been associated with substantial area loss. Since the late 1950s, the USGS has maintained a long-term glacier mass-balance program at three North American glaciers. annual balance was -2.04 m. Gulkana Glacier (lat 63'15' N., 1,700-m mean equilibrium line altitude) had a winter balance of 1.05 m, approximately normal for this glacier; the final annual balance was -0.30 m. INTRODUCTION The purpose of the International Hydrological Decade (1965-74) is to increase the understanding and to promote Mass balance is typically calculated over a balance year, which begins at the onset of snow and ice accumulation. The Jarvis Glacier is located north of the Gulkana Glacier; a drilling project was conducted on the glacier in April 2017 (Miner et al., 2018). 4A) was relocated at 2,020-m altitude in the eastern cirque of Gulkana Glacier. Principal investigators are listed for submitted data of 2018/19. Gulkana Glacier is located on the south side of the Alaska Range about 10 miles north of Paxson, along the Richardson Highway. 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. Ice motion also slowed, which combined with the negative mass balance, resulted in glacier retreat under a warming climate. During 1997-2001, Gulkana Glacier showed a continued and accelerated negative mass balance trend, especially below the equilibrium line altitude where thinning was pronounced. Using data for the last 10 years and the first 10 years of the dataset, calculate the average annual glacier-wide mass balance … Table 2: Reported mass balance values of the observation period 2017/18, 2018/19 as well as *preliminary values for 2019/20. This paper presents a brief review of the glacier mass balance status and their analysis under the changing climate in the Indian Himalayan Region (IHR). Alaska Table 1. Glacier mass balance is the direct and non delayed response against the climate change and hence it is one of the essential variables require to monitor the climate system. Negative values indicate a net loss of ice and snow compared with the base year. change from digital date, west gulkana glacier, alaska l. sam thompson and stephen e. smith ..... 11 determination of 1957-1986 mass balance of west gulkana glacier, alaska, by comparison of topographic maps fred b. chambers ..... 19 two-year mass balance of west gulkana glacier, alaska This map is of the same glacier depicted in the photos attached later in the lesson. USGS began biannual measurements of glacier mass balance and meteorology at Alaska's Wolverine and Gulkana glaciers in … The trends of climate change indicate that glacier melt will continue to increase. Validation of Glacier Mass Balance Modeling Using USGS Measurements  The PTAA model uses the bias-reduced MM5-down-scalings (daily maximum and minimum temperatures and precipitation) as inputs in combination with the area altitude distribution of Gulkana Glacier to simulate the Gulkana Glacier mass balances. These glaciers have the longest continuous mass-balance records in North America, with winter balance B w, summer balance B s, and annual balance B a data available from 1959 to 2011 for South Cascade Glacier (World Glacier Monitoring Service 2012, 2013) and from 1966 to 2015 for Wolverine and Gulkana Glaciers (O’Neel et al. For example, the balance year at Gulkana Glacier starts and ends in September of each year. Explaining mass balance and retreat dichotomies at Taku and Lemon Creek Glaciers, Alaska. ciers: Wolverine Glacier in Alaska’s Kenai Range, Gulkana Glacier in the Alaska Range, and South Cas-cade Glacier in Washington State’s Cascade Range (Fig. The USGS has measured the mass balance on Gulkana Glacier since 1967 as part of a program to document long-term glacier and climate trends. The focus is on modeling mass balance and discharge of the Gulkana Glacier in Alaska and applying a climate change scenario in order to determine the magnitude of the effects of climate change on the Gulkana glacier and how the melt water will contribute to total sea level rise.