ClimaTea Journal Club

Date: 

Tuesday, February 16, 2016, 3:00pm

Location: 

HUCE Seminar Room

This week GS Colin Meyer leads the discussion on the attached paper "Flow variability and ongoing margin shifts on Bindschadler and MacAyeal Ice Streams, West Antarctica" by Hulbe et. al. 2016. Here are Colin's thoughts on the paper:

Narrow bands of fast-flowing ice, called ice streams, drain the majority of the grounded ice from the interior of both Greenland and Antarctica to the coast. The ice streams on the Siple Coast of the West Antartic Ice Sheet drain into the Ross Sea. In this region there is a net accumulation of ice mass due to a stagnation of Kamb Ice Steam about 150 years ago. Some open questions on ice streaming are:

1. How, why, and where do they form?
2. What sets the width of an ice stream if it is not laterally constrained?
3. Do the margins migrate? How fast are they migrating?
4. Why do they shut down and reactivate?

As ice streams are the most significant components in the mass loss from the ice sheet, these questions are important for understanding the stability of the West Antarctic Ice Sheet in a warming world. Hulbe et al. (2016) present new evidence for short-time flow variability in Siple Coast Ice Streams. Moreover, they have a nice presentation that overviews observational evidence for margin locations and the historic stagnation of Siple Ice Stream. Through the paper, Hulbe et al. also review much of the terminology, e.g. margins, sticky spots, stagnation, reactivation etc. as well as a description of the bed processes. They include technical details on the errors induced by their methods, which I will no focus on. Overall, the paper achieves its aim of demonstrating decadal variability in ice stream flow but, in my opinion, neglects connections to some of the larger unanswered questions.
hulbe_et_al-2016-journal_of_geophysical_research_earth_surface.pdf16.13 MB