USGS Benchmark Glacier Mass Balance and Project Data

Abstract

Since the late 1950s, the USGS has maintained a long-term glacier mass-balance program at three North American glaciers. 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. Additional measurements have been made on Lemon Creek and Taku glaciers, AK to compliment data collected by the Juneau Icefield Research Program (JIRP; Pelto et al., 2013). Direct field measurements of point glaciological data are combined with weather and geodetic data to derive glacier-wide seasonal and annual surface mass balance solutions of each glacier in conventional and reference surface formats (Cogley et al., 2011). Additional details on the calculation of glacier-wide surface mass balance are described in Van Beusekom et al. (2010). Mass balance is calculated at both a seasonal and annual time-step at each glacier in both a conventional and reference surface format (Cogley and others, 2011). The analysis framework (Van Beusekom and others, 2010; O’Neel and others, 2014) is identical at each glacier to enable cross-comparison between output time series. Vocabulary used follows Cogley and others (2011) Glossary of glacier mass balance. Mass balance is calculated from direct field measurements of surface mass balance in combination with weather data and imagery analyses.