Fingerprinting ice sheet meltwater sources with transient rheology#
The last 3 months have been a busy time at Brown University. Allie Coonin, a PhD student with PI Harriet Lau, submitted a paper (with co-author Sophie Coulson, University of New Hampshire) that explores how transient rheology might improve our constraints on which major ice sheets contributed to Meltwater Pulse 1A. This paleoclimate event, ~ 14,000 years BP, involved a catastrophic 10-20 m rise in global mean sea level, within only 500 years. When ice sheets melt, Earth’s surface mass is redistributed across the globe causing the solid Earth to deform. Due to the “short” duration of this event, previous geophysical studies have treated the Earth as an elastic solid. However, our understanding of broadband rheology implies that even at these fast timescales, deformation is far from elastic. Transient rheology not only improves our estimates of the ice budget, but constrains the chronology of the melt – providing valuable lessons for ice sheet collapse today. Look out for Coonin et al. in the near future!