Document Type

Article

Publication Title

Journal of Glaciology

Publication Date

2005

First Page

407

Last Page

422

Issue Number

174

Volume Number

51

Abstract/ Summary

We investigate causes of the stratigraphic variation revealed in a 177 km, 400 MHz short-pulse radar profile of firn from West Antarctica. The profile covers 56 m depth, and its direction was close to those of the ice flow and mean wind. The average, near-surface accumulation rates calculated from the time delays of one radar horizon consistently show minima on leeward slopes and maxima on windward slopes, confirming an earlier study based on stake observations. The stratigraphic variation includes up to 30 m depth variation in individual horizons over tens of km, fold limbs that become progressively steeper with depth, and fold-hinge loci that change direction or propagate down-ice with depth over distances far less than predicted by the ice speeds. We use an accumulation rate model to show how local rate anomalies and the effect of ice speed upon a periodic variation in accumulation rate cause these phenomena, and we reproduce two key features seen in the stratigraphic variations. We conclude that the model provides an explanation of changes in spatial stratigraphy and local measures of accumulation history given the constraints of surface topography, ice and wind velocities, and a general accumulation rate for an area.

Citation/Publisher Attribution

Arcone, SA, Spikes, VB, and Hamilton, GS, 2005, Stratigraphic Variation Within Polar Firn Caused By Differential Accumulation and Ice Flow: Interpretation of a 400 Mhz Short-Pulse Radar Profile from West Antarctica: Journal of Glaciology, v. 51, p. 407-422. Available on publisher's site at: http://www.ingentaconnect.com/content/igsoc/jog/2005/00000051/00000174/art00009

Publisher Statement

© Copyright 2005 by the International Glaciological Society

DOI

10.3189/172756505781829151

Version

publisher's version of the published document

Share