Linking Oregon Salt Marsh Horizontal & Vertical Sediment Accumulation Rates


Background: Previous research of vertical sediment accretion rates suggests that most Oregon salt marshes have survived 20th century relative sea level rise by accumulating sediment at a pace similar to or exceeding the rate of sea level rise, except Salmon River Estuary and Alsea Bay (Peck et al. 2020). Additionally, though we predict that salt marsh growth can only occur under rising sea level and is limited by the rate of relative sea level rise, Nehalem Bay salt marshes are growing much faster than the local pace of sea level rise and salt marshes in the Coquille River estuary are growing vertically despite experiencing relative sea level fall. Are these vertical patterns of sediment accumulation also reflected in the patterns of horizonal growth of the salt marshes?

Status: I'm currently analyzing aerial photographs from a number of estuaries along the Oregon coast from the late 1930s to the present and comparing these rates of salt marsh expansion and contraction with rates of vertical growth measured previously in sediment cores. I plan on presenting this research at AGU 2020.