A powerful 9.0 magnitude earthquake hits off the coast of Vancouver Island, resulting in widespread devastation with thousands of casualties and injuries. The ensuing tsunami, aftershocks, and ensuing chaos only add to the unfolding tragedy.
Survivors, desperate to find their loved ones, flood overwhelmed hospitals. The earthquake damages road and rail connections, which are then further impacted by tsunami flooding. This catastrophic “megathrust” earthquake scenario, detailed in a B.C. government risk assessment, predicts over 3,400 fatalities and more than 10,000 injuries on the main shock day.
The report outlines staggering costs of $128 billion, the destruction of 18,000 buildings, and significant damage to 10,000 more structures. Economic growth is halved, with GDP and job losses extending over the next decade, surpassing the collective impact of all previous disasters in B.C. over two centuries.
The most severe damage is anticipated on Vancouver Island and a 20-kilometer coastal stretch from the U.S. border to the Sunshine Coast, including Vancouver. This analysis is part of the B.C. disaster and climate risk assessment, dated October 2025, which also covers other extreme event scenarios like severe flooding in the Fraser Valley and urban interface fires.
Edwin Nissen, a professor of earth and ocean sciences at the University of Victoria, notes that the report’s estimates are based on simulations of earthquake impact and building resilience. Different factors such as building materials, location, and building codes play a crucial role in determining structural integrity during earthquakes.
Nissen emphasizes the importance of regular updates to emergency reports due to rapidly evolving scientific and engineering advancements. The last comparable earthquake in the region occurred in 1700, with the report indicating a two to ten percent likelihood of a similar event in the next three decades.
While the Cascadia fault zone poses a significant seismic threat, the unpredictability of earthquakes underscores the need for constant preparedness. Nissen highlights the lack of moderate earthquakes in the Cascadia subduction zone, emphasizing the need for vigilance despite the zone’s relative quietness in terms of seismic activity.