In 1999 Barclay was appointed to the University of East Anglia. Her research combines geological investigations into the dynamic processes of volcanoes with analysis of the social and cultural landscapes in which they erupt in. She served as Principal Investigator on Strengthening Resilience to Volcanic Hazards (STREVA), looking to develop a practical volcanic risk assessment framework, which was supported by the Natural Environment Research Council and Economic and Social Research Council. During STREVA Barclay worked with people from Saint Vincent and the Grenadines to document the historical and culture record of the 1902 and 1979 La Soufrière eruptions. As part of the programme, the researchers worked with the University of the West Indies to create a portable exhibit that toured the Caribbean. She combined historical archives, field measurements and meteorological modelling to reconstruct the La Soufrière eruptions. This allowed her to understand how the wind flow around volcanoes controls the movement of ash plumes through the atmosphere, depositing ash both close to the volcano and far away. In her work with communities in Ecuador Barclay showed that volcanic risk can be improved with collaborative monitoring. This work has inspired her latest project, Tomorrow's Cities, which looks at urban disaster risk in cities including Quito. Barclay has argued that the deaths that occur due to pulses of gas and solids after a volcano are avoidable.