A Geospatial Analysis of Glacier Volume Change

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This project will provide a data-driven, global assessment of glacier volume changes with objectively quantified uncertainties. Ocean thermal expansion (due to increasing ocean temperatures) and mountain glacier ice loss (due to increased glacier melt rates) have contributed most to global mean sea level rise (SLR) and are expected to continue to dominate SLR over at least the coming century. Unfortunately, the uncertainties in recent glacier contributions to SLR and current volume of glacier ice remain high due, in part, to limited data on glacier volume changes. The improved estimates of historical glacier changes and current glacier volume from this project will provide a critical step towards assessing changes in SLR, quantifying glacier sensitivity to environmental variability, and providing accurate projections of future SLR and its associated societal impacts. This project will involve undergraduate and graduate students and will also develop educational lab kits for K-12 classrooms. These kits will communicate the results of this research to school teachers and students, while simultaneously providing hands-on, real world, geographical and spatial science exercises. The proposed work will quantify regional glacier volume/mass changes over the past approximately 150 years to significantly improve the spatial and temporal estimates of glacier changes and the associated contributions to SLR. Investigators will include all mountain glaciers and ice caps across the globe in their analysis. The investigators will also quantify the current spatial distribution of volume of glacier ice using observations from the initial phase of the research to constrain a glacier model. This will be accomplished using a combination of techniques (automated cloud characterization schemes, NDSI, photogrammetry, photoclinometry) applied to a suite of remotely sensed data and historical imagery to map glacier area and volume changes over the past several decades. The investigators will use this information to constrain spatially-varying scale factors for a glacier volume-area scaling model. This work will extend back in time to the Little Ice Age (LIA) by compiling reliable moraine dates and maps, and automated mapping of LIA moraines. The volume of ice around the end of the LIA will be calculated, which will permit placing the spatial and temporal patterns in glacier volume change into context relevant to assess anthropogenic changes. These new glacier volume and volume change estimates will be used to estimate regional patterns of past and future contributions of glaciers to SLR and identify specific regions where glacier changes and contributions to future SLR are likely to be significant. Thus, this research project will focus on glacier contribution to SLR globally and will provide new insights estimating the impacts of SLR in many countries, including the United States.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.