Variations in Alaska tidewater glacier frontal ablation, 1985-2013

Robert W McNabb, Regine Hock, Matthias Huss

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Our incomplete knowledge of the proportion of mass loss due to frontal ablation (the sum of ice loss through calving and submarine melt) from tidewater glaciers outside of the Greenland and Antarctic ice sheets has been cited as a major hindrance to accurate predictions of global sea level rise. We present a 28 year record (1985–2013) of frontal ablation for 27 Alaska tidewater glaciers (representing 96% of the total tidewater glacier area in the region), calculated from satellite‐derived ice velocities and modeled estimates of glacier ice thickness. We account for cross‐sectional ice thickness variation, long‐term thickness changes, mass lost between an upstream fluxgate and the terminus, and mass change due to changes in terminus position. The total mean rate of frontal ablation for these 27 glaciers over the period 1985–2013 is 15.11 ± 3.63Gta−1. Two glaciers, Hubbard and Columbia, account for approximately 50% of these losses. The regional total ablation has decreased at a rate of 0.14Gta−1 over this time period, likely due to the slowing and thinning of many of the glaciers in the study area. Frontal ablation constitutes only ∼4% of the total annual regional ablation, but roughly 20% of net mass loss. Comparing several commonly used approximations in the calculation of frontal ablation, we find that neglecting cross‐sectional thickness variations severely underestimates frontal ablation.
Original languageEnglish
Pages (from-to)120-136
Number of pages17
JournalJournal of Geophysical Research: Earth Surface
Volume120
Issue number1
Early online date26 Jan 2015
DOIs
Publication statusPublished - 16 Feb 2015

Keywords

  • glacier dynamics
  • frontal ablation
  • ice thickness

Fingerprint Dive into the research topics of 'Variations in Alaska tidewater glacier frontal ablation, 1985-2013'. Together they form a unique fingerprint.

  • Profiles

    No photo of Robert McNabb

    Robert McNabb

    Person: Academic

    Cite this