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The glacial geology community has developed digital reconstructions of Pleistocene glaciers in the western U.S. through decades of regionally focused research and interpretations of geologic maps. These paleoglacier reconstructions afford an opportunity to develop paleoclimate reconstructions for the Late Quaternary in the western U.S., especially when combined with cosmogenic chronologies and other paleoclimate proxies and model output. Here, we present a geospatial database of Late Pleistocene mountain glaciers for the conterminous western U.S. based on compilations of paleoglacier reconstructions spanning glaciated mountains in the region. The database consists of paleoglacier outlines as georeferenced polygons drawn at scales ranging from 1:24,000 to 1:100,000, reflecting differences in available mapping data and degrees of confidence in identifying glacial deposits and landforms used to identify paleoglacier limits. The database is available as a web feature service designed to be easily represented in a geographic information system or web mapping application to enable visualization of the pattern of Late Pleistocene mountain glaciation and analysis of paleoglacier outlines and derivative products, such as equilibrium-line altitudes and boundaries of modeled paleoglaciers. We illustrate potential applications of the database for visualization and data assimilation with an example from mountains neighboring the Lake Bonneville basin, where paleoglacier outlines are based on 1:24,000 scale mapping of glacial deposits and landforms and cosmogenic chronologies of moraines are abundant. For this research, the database enables an analysis of the pattern of glaciation in the region and, through assimilation with chronological data, an assessment of the relative timing of glacier maxima and the time when Lake Bonneville overflowed. While the database can be easily shared among users and represented in a geographic information system, development of the database requires community input to maximize its utility for users across disciplines. A goal of this presentation is to encourage interested users to share ideas for developing an accessible, scalable, and community-supported database of paleoglaciers.
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This content will become publicly available on June 28, 2026
PG-Tools: A framework and an ArcGIS toolbox to standardize paleoglacier outlines and attributes
The Pleistocene Epoch was characterized by extensive glacier systems in numerous mountain ranges around the world. Mapping glacial landforms and deposits over many decades of prior work has afforded reconstructions of mountain glaciers, chiefly during the last Pleistocene glaciation and subsequent deglaciation. The availability of high-resolution satellite imagery, digital terrain models, and numerical chronologies of glacial deposits and landforms provides opportunities for mapping paleoglacier outlines and reconstructing ice thickness and volume during specific periods across glaciated regions at different spatial scales. Most paleoglacier reconstructions require outlines corresponding to a specific valley and terminus. However, various formats of digital paleoglacier outlines exist in the literature, some of which encompass entire glacier complexes or ice caps without differentiating between individual valleys and outlet glaciers. Also, unlike inventories of present-day glaciers such as the Randolph Glacier Inventory, digitized paleoglacier outlines lack standardized attributes. In this study, we developed an ArcGIS toolbox to subdivide paleoglacier outlines into individual polygons constrained within watershed boundaries (drainage basins) and to derive a consistent set of attributes related to the geometry, topography, and ice thickness of paleoglaciers. We demonstrate the applications of this toolbox in glaciated mountain areas in Costa Rica, the western U.S., and the central Tibetan Plateau. Although some manual adjustments are still necessary, this toolbox provides an efficient means to standardize the format and derive attributes for paleoglacier outlines. Our proposed framework and newly developed ArcGIS toolbox for standardizing paleoglacier outline formats and attributes improve the value, accuracy, and utility of paleoglacier mapping and paleoclimate reconstruction, and facilitate consistency and comparability among model simulations of glacier and climate changes from the past to present and into the future.
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- Award ID(s):
- 2223354
- PAR ID:
- 10644062
- Publisher / Repository:
- Geomorphology
- Date Published:
- Journal Name:
- Geomorphology
- ISSN:
- 1872-695X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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