by Professor John Clague
Emeritus Professor at Simon Fraser University
Geologists and geophysicists working along west coast of North America from northern California to southwest British Columbia have demonstrated that giant (magnitude-9) earthquakes occur along the Cascadia subduction zone, where the oceanic Juan de Fuca plate moves down beneath the edge of North America.
The most recent of these earthquakes happened in January 1700. Satellite GPS data extending back to the mid-1990s shows a pattern of surface deformation consistent with locking of the megathrust fault separating the Juan de Fuca and North America plates in the build-up to the next giant earthquake. Although the next of these earthquakes will damage all cities along the length of the subduction zone, the possible damage from far more frequent, magnitude 6 and 7 crustal earthquakes is greater than that of much larger plate-boundary events.
John Clague is Emeritus Professor at Simon Fraser University. He was educated at Occidental College (BA), the University of California Berkeley (MA), and the University of British Columbia (PhD). Clague worked as a Research Scientist with the Geological Survey of Canada from 1975 until 1998. In 1998 he accepted a faculty position in Department of Earth Sciences at Simon Fraser University, where he worked until 2016. Clague is a geologist with research specializations in glacial geology, geomorphology, natural hazards, and climate change.