Recent research published in the Proceedings of the National Academy of Sciences (PNAS) has highlighted an alarming trend concerning increased flood exposure in the Pacific Northwest following potential earthquakes and rising sea levels. The study focuses on the coasts of Washington, Oregon, and northern California, which are at risk of experiencing significant coastal subsidence of up to two meters due to an anticipated earthquake along the Cascadia subduction zone. This sudden change in elevation could dramatically alter sea levels, expand floodplains, and heighten flood risks for nearby communities.
A team of more than a dozen researchers contributed to the study, including Harvey Kelsey, a research associate at Cal Poly Humboldt. Kelsey explained that the coastal region is susceptible to subduction zone earthquakes, wherein the oceanic plate is forced beneath the continental plate, resulting in significant geological activity.
Kelsey noted, “This area experiences what are known as subduction zone earthquakes, caused by the interaction between the oceanic and continental plates.” The movement can be gradual or abrupt, leading to substantial seismic events. According to Kelsey, such earthquakes typically occur every 300 to 800 years, making their prediction inherently uncertain but highlighting the historical pattern of seismic activity in the region.
While the last notable subduction zone earthquake took place about 300 years ago, researchers foresee not just the immediate impacts of earthquakes but also a long-term gradual rise in sea levels. “Within the next century, we expect the sea level along these coasts to rise by approximately one and a half to two and a half feet, which is a considerable increase,” Kelsey added.
This study serves as an important reminder of the ongoing geological dynamics at play and the need for preparedness in coastal communities. The rising sea levels combined with the risk of sudden earthquakes underscore the necessity for research and proactive measures to mitigate the impact of potential flooding and enhance community resilience.
Overall, while the information may seem concerning, it emphasizes the importance of scientific research and community awareness to address and prepare for such natural threats.