Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets

Mass loss from marginal glaciers along the Greenland and Antarctic ice sheets is known to be contributing to sea-level rise but the precise magnitude and mechanisms are unclear, making it difficult to predict its potential future contribution to sea level. Surface mass loss is certainly a factor. Ice loss from faster glacier flow — called dynamical thinning — has been more difficult to pin down. High-resolution satellite altimetry measurements now show that dynamical thinning is far more important and extensive than previously thought, especially at ocean margins.