This lecture has been presented each year since 1981 and is one of the principal events in the British Geophysical Association calendar. The Bullerwell lecture, named after the first Chief Geophysicist of the British Geological Survey, is a prestigious event that has been given by many of those UK geophysicists (see below) who are major international Earth Scientists, receiving honours from a wide range of learned societies, academic and governmental institutions. This years recipient is Dr. Sanne Cottaar of Cambridge University. Dr Sanne Cottaar studies the structure, composition, and dynamics of the deep Earth, and their relationship to surface processes and planet history. Her approach is both data-driven, hunting for clues constraining the deep Earth; and forward-modelling, predicting the possibilities and limitations of seismic data based on recent results in mineral physics and geodynamics. She holds a PhD from the University of California, Berkeley, and an MSc from the University of Utrecht.