Brief Communication: Twelve-year cyclic surging episodes at Donjek Glacier in Yukon, Canada

Takahiro Abe,Daiki Sakakibara,Masato Furuya

doi:10.5194/tc-10-1427-2016

Abstract

Abstract. Surge-type glaciers repeat their short active phase and their much longer quiescent phase usually every several decades or longer, but detailed observations of the evolution cycles have been limited to only a few glaciers. Here we report three surging episodes in 1989, 2001, and 2013 at Donjek Glacier in the Yukon, Canada, indicating remarkably regular and short repeat cycles of 12 years. The surging area is limited within the ∼ 20 km section from the terminus, originating in an area where the flow width significantly narrows downstream, suggesting a strong control of the valley constriction on the surge dynamics.

Highlights

During their short (1–15 years) active phase, surge-type glaciers typically speed up severalfold to over an order of magnitude, resulting in significant thickness changes and kilometre-scale terminus advance (Meier and Post, 1969; Raymond, 1987; Harrison and Post, 2003)
Because of the lower spatial resolution of the images prior to 1986, we could not derive the velocities between 1973 and 1985, but the images were helpful to examine the terminus changes even in the 1970s. These images were acquired by the Landsat 1–5 Multi-Spectral Scanner (MSS), the Landsat 4–5 Thematic Mapper (TM), the Landsat 7 Enhanced Thematic Mapper Plus (ETM+), and the Landsat 8 Operational Land Imager (OLI), all of which are distributed by the USGS
During the three active phases, the speed-up regions are mostly limited to the ∼ 20 km section from the terminus, which we associate below with the shape of the glacier

Summary

Introduction

During their short (1–15 years) active phase, surge-type glaciers typically speed up severalfold to over an order of magnitude, resulting in significant thickness changes and kilometre-scale terminus advance (Meier and Post, 1969; Raymond, 1987; Harrison and Post, 2003). In their quiescent phase (tens to hundreds of years), they flow slowly or become stagnant. In Svalbard polythermal glaciers, the speed-up is gradual, leading to years-long active surging For these glaciers, the active-phase duration and the recurrence interval are much longer than those in the temperate Alaskan-type. Here we report our findings of three surging events as well as a likely surging event pre-1985

Donjek Glacier

Data and method

Results

Discussion and conclusion