Relative sea- and land- level change in Port Alberni, British Columbia over the last 700 years

Sea-level change in Northern Cascadia is influenced by eustatic and tectonic processes. Tectonic processes from the Cascadia Subduction Zone are a major driving force of instantaneous and gradual sea-level change along Vancouver Island due to coseismic/interseismic (subsidence/uplift) periods. In this thesis, I use marsh stratigraphy, microfossils, and a Bayesian framework to reconstruct a 700-year-long record of relative sea-level change at Port Alberni, British Columbia, Canada. Results of a Bayesian Transfer function show that relative sea-level rose by 0.59  0.35 mm/year over the past 700 years. Captured within this temporal range is the 1700 C.E. earthquake, and a second event between 1340 and 1402 C.E. which is only correlatable across Northern Cascadia, and that contributed to 42 ± 22 cm of coseismic and, or interseismic subsidence. These findings provide further evidence that Northern Cascadia is susceptible to both full-margin and partial ruptures, and shorter seismic reoccurrence intervals than previously estimated.