Supplementary material to "Subglacial drainage characterization from eight years of continuous borehole data on a small glacier in the Yukon Territory, Canada"

Abstract

Understanding the physical processes that control the growth and decline of glaciers is vital to create models capable of forecasting how changing glaciers will affect the geography, biosphere and climate. This PhD thesis investigates basal sliding, which corresponds to the increase in speed a glacier experience by sliding downhill over the underlying terrain. We have studied a glacier in the Yukon Territory, Canada, installing over 300 pressure sensors at the base of the glacier to understand how water can create there a subglacial drainage system and accelerate or slowdown the glacier. Contrary to the predictions of current subglacial hydrology models, we found that different regions of the bed are typically either hydraulically well-connected or disconnected, and the transition between these two regimes is generally abrupt. Also, we found that the extent of areas hydraulically disconnected from the surface seems to have a very significant role in controlling basal sliding. v Preface This PhD thesis is based on multiple datasets acquired over nine consecutive years starting on 2008 by a group from the University of British Columbia led by Professor Christian Schoof, and a group from Simon Fraser University led by professor Gwen Flowers. I actively participated in fieldwork preparation, design, and execution between the years 2012 and 2016. During this period, I collaborated in the drilling of boreholes, and the installation and maintenance of pressure sensors, data loggers, GPS towers, and repeat photography cameras. I designed and built the repeat photography cameras, the digital sensors, and their associated data loggers. I conducted all of the borehole data analysis and wrote the manuscript with the close collaboration of my supervisor Christian Schoof, who provided numerous corrections and suggestions. A version of Chapter 2 has been published: Camilo Rada & Christian Schoof "Channelised, distributed, and disconnected: subglacial drainage under a valley glacier in the Yukon", The