Jürgen Ehlers studied Geography at the University of Hamburg. In 1978 he did his PhD with a study in glacial geomorphology. Since then Ehlers worked at the Geological Survey of Hamburg, where he was in charge of the geological mapping until his retirement in 2013. He organised the INQUA project Extent and Chronology of Quaternary Glaciations with both Phil Gibbard and Phil Hughes and this global compilation was published in 2011.   Philip Hughes is Reader in Physical Geography at The University of Manchester, UK. He studied for his first degree reading geography at the University of Exeter graduating in 1999. This was followed by a Masters in Quaternary Science, then a PhD in Geography, both at the University of Cambridge (Darwin College). He is Subject Editor in Geomorphology and Quaternary Geology for the Journal of the Geological Society.   Philip Gibbard is Professor of Quaternary Palaeoenvironments at the University of Cambridge, UK, and a Dosent in the University of Helsinki, Finland. He is past-chair of the International Commission on Stratigraphy's Quaternary Subcommission. He is currently President, and was formally Secretary and member, of the Stratigraphy and Geochronology Commission of INQUA, and is a member of the INQUA Subcommission of European Quaternary Stratigraphy and the Geological Society of London's Stratigraphy Commission. His research is focused on Quaternary and late Tertiary terrestrial and shallow marine sedimentation, stratigraphy and palaeoenvironmental evolution throughout Europe, but he has also worked in the Arctic, North America, India and South-East Asia.