May 15, 2017

Mass transport waves amplified by intense Greenland melt and detected in solid Earth deformation

Adhikari, S., Ivins, E. R., Larour, E.
Geophysical Research Letters
  • States that the annual cycle and secular trend of Greenland mass loading are well recorded in measurements of solid Earth deformation
  • States that horizontal crustal displacements can potentially track the spatiotemporal detail of mass changes with great fidelity
  • Analyzes Greenland crustal motion data, which reveals that a significant excitation of horizontal amplitudes occurs during the intense melt years
  • Discovers that solitary seasonal waves of substantial mass transport (1.67 ± 0.54 Gt/month) traveled at a maximum speed of 7.1 km/month through Rink Glacier in 2012
  • Deduces that intense surface melting enhanced either basal lubrication or softening of shear margins, or both, causing the glacier to thin dynamically in summer
  • Finds that the newly routed upstream subglacial water was likely to be both retarded and inefficient, thus providing a causal mechanism for the prolonged ice transport to continue well into the winter months
  • Concludes that as the climate continues to produce increasingly warmer spring and summer, amplified seasonal waves of mass transport may become ever more present with important ramifications for the future sea level rise