Correlations of suspended sediment size with bedrock lithology and glacier dynamics

• Published in: Annals of Glaciology
• Main Authors: Jeff W. Crompton, Gwenn E. Flowers
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2016
• Subjects: glacier surges; subglacial processes; subglacial sediment; grain size distribution; St. Elias Mountains; Meteorology. Climatology; QC851-999; Annals of Glaciology
• Online Access: https://doi.org/10.1017/aog.2016.6; https://doaj.org/article/20f47f80d4ce43cf9c00c160dafa5857

The hypothesized link between glacier surging and bedrock geology motivates this study of the suspended sediment size distributions (SSSD) from surge-type and non-surge-type glaciers. We analyze SSSDs from proglacial streams in 20 individual basins comprising various fractions of metasedimentary (MS) and felsic plutonic rocks. We compare the size distributions by performing tests of significance on the distribution statistics, and a principal component analysis on discrete grain sizes. We find that surge-type and non-surge-type glaciers underlain solely by MS rocks have significantly different SSSDs, while surge-type glaciers as a whole have remarkably similar SSSDs, regardless of the underlying bedrock geology. These observations hint at a relationship between sediment characteristics and glacier surging, though causation in either direction cannot be established without additional data.