Geophysics Seminar - Emily Geyman, "Learning from landscapes: The climate sensitivity of glaciers and the mechanics of soil production"

Many processes shaping Earth’s surface unfold over timescales that are too long to observe directly. I will present two vignettes illustrating how space-for-time substitution approaches allow us to leverage observations across space to constrain both rates and mechanisms of change over time. In the Arctic Archipelago of Svalbard, historical reconstructions of 1,594 glaciers reveal how ice loss varies across climate gradients, providing an empirical basis for quantifying the sensitivity of ice loss to warming. Along the San Andreas Fault in central California, lateral plate motion places successive stages of landscape evolution side by side, revealing how rock weakening regulates soil production (the conversion of rock to soil). I will close with a preview of new work with Ching-Yao Lai at Stanford, using optical and radar satellite observations on the Greenland Ice Sheet to quantify meltwater delivery to the bed, infer subglacial drainage efficiency, and constrain how these processes regulate ice motion.

Speaker-suggested reading:

Geyman, E.C., Paige, D.A. & Lamb, M.P. The contribution of rock strength to soil production. Nature 647, 921–927 (2025). https://doi.org/10.1038/s41586-025-09751-z