Recent Earthquakes Raise Concerns in Metro Vancouver: What to Expect Next
On October 4, 2023, a magnitude 3.5 earthquake struck Metro Vancouver, following a 3.8 magnitude quake on September 26. Experts, including Simon Fraser University’s John Clague, caution that while minor earthquakes are common, the region’s seismic activity could indicate the potential for more significant incidents in the future, stressing the importance of preparation.
Residents of Metro Vancouver experienced a minor earthquake on October 4, 2023, measuring a magnitude of 3.5. This tremor occurred at approximately 2 a.m. and was located 18 kilometers west of Delta and east of Ladysmith, B.C., at a depth of 65 kilometers. Notably, just days earlier, a slightly larger earthquake with a magnitude of 3.8 struck Haro Strait. This quake was reported around 4 a.m. on September 26 and was deep enough at 55 kilometers that it affected individuals across a broad region, from Nanaimo to Washington State. Professor Emeritus John Clague from Simon Fraser University highlights that, while minor earthquakes of lower magnitudes are routine in British Columbia, the recent locations of these seismic events have raised concerns. “We have known for quite some time that these earthquakes occur beneath Puget Sound,” Clague remarked, emphasizing the proximity of the recent quakes to the Lower Mainland. The possibility of a more significant earthquake occurring closer to Vancouver cannot be dismissed. Although earthquakes verging on magnitude 3 or 4 are generally not harmful, those reaching a magnitude of 5 can cause damage near the epicenter. An example cited was the 1975 tremor beneath Pender Island, which resulted in noticeable swaying in high-rises across Vancouver. Concerns linger about the ‘Big One,’ a potential cataclysmic event characterized by a significant slip between the Juan de Fuca Plate and the North American Plate in the Cascadia subduction zone. Clague notes, however, that although such a magnitude 8 or 9 earthquake may be inevitable, it happens only once every 400 to 500 years. In contrast, experts consider smaller earthquakes more probable in the near term. Such seismic adjustments along the fault lines may lead to significant local quakes; indeed, Clague emphasizes, “It does not mean that we are approaching a magnitude 7 or higher earthquake.” Factors influencing the damage of any future quakes include magnitude, epicenter location, and depth. Highly damaging earthquakes are typically those that are shallow and located near populated areas. The occurrence of earthquakes is not contingent upon the time of day. They can take place at any hour and are often underreported at night, particularly if their severity is low. Clague elaborates that smaller quakes often feel like minor sensations, such as someone bumping against a chair, and their effects diminish significantly depending on their depth before reaching the surface. In summary, while numerous small earthquakes are common in British Columbia, the recent quakes near Metro Vancouver serve as a reminder of the region’s seismic nature and the potential for more significant events in the future.
Metro Vancouver lies within a seismically active zone due to the proximity of the Juan de Fuca Plate and the North American Plate. Earthquakes occur frequently in this region, with many being of lower magnitude and largely unnoticed. Generally, these minor tremors do not pose a threat; however, concerns arise when patterns of recent activity suggest the potential for more significant quakes. Geologists and earth science experts continuously monitor seismic data to assess risks and prepare for possible large-scale events, including the anticipated ‘Big One.’
In conclusion, while Metro Vancouver frequently experiences minor seismic activity, the occurrence of two recent earthquakes raises valid concerns regarding the likelihood of future tremors. Although a catastrophic event like the ‘Big One’ is not imminent, the data suggests the potential for a smaller, damaging earthquake is plausible, particularly given the conditions of the region’s geological makeup. Residents are reminded of the importance of earthquake preparedness regardless of the time or magnitude of tremors experienced.
Original Source: www.delta-optimist.com
