As glaciologist I study the mass balance of the polar cryosphere with focus on sea ice – ocean – ice shelf interaction. I discovered the instability of Antarctic outlet glaciers following the Larsen-A ice shelf collapse, and lead a research group pioneering the satellite based measurement of grounding line ice thickness in Antarctica. As a research tool for mapping ice dynamics and thickness I make use of satellite remote sensing (Synthetic Aperture Radar – SAR; interferometric SAR - InSAR). An essential part of my research is satellite validation using airborne measurements (electromagnetic induction sounding of sea ice), ground based geophysics (phase sensitive radar for detecting basal melting of ice shelves; GPS and tiltmeters for ice shelf tidal bending), amongst other glaciological research tools. I spent 15 field seasons in Antarctica, and participated in ground validation and airborne geophysical work in the Arctic (Greenland, Svalbard), Patagonia, and the Alps (Europe and New Zealand). More recently, I lead a team for developing a drone system to measure snow depth on sea ice, and participated in airborne sea ice thickness measurements in the Ross Sea.