[1] Foulger plays a major role in coordinating the global debate in the category of Earth Science, on whether or not deep mantle thermal plumes exist and create “hot spot” volcanism.
[5] Challenging the mantle plume hypothesis, Foulger has posited that there is no chemical or isotopic data that require deep-plume origins nor are there anomalously elevated temperatures indicating the existence of such.
Plumes, in her estimation, cannot therefore account for the eruption rates of the largest flood basalts, which she suggests could be explained alternatively by rapidly draining reservoirs of molten rock that have accumulated over time.
[8] From 1996 to 2004 Gillian Foulger, along with others such as Bruce Julian, Keith Richards-Dinger, and Francis Monastero monitored seismic activity using the arrival times of the U.S. Navy's seismometer network in the Coso Volcanic Field's geothermal area in California, in order to calculate the local-earthquake topography images.
[10] In June 2021, Foulger reported that under her leadership experts from the Department of Earth Sciences at Durham University believed they had discovered a submerged continent stretching from Greenland to Europe.