Chapter 5: Marine Terraces on Eastern Santa Cruz Island: Sculpting an Island by the Land-sea Intersection

Alisha N. Clark & Jacob A. Selander

Emergent marine terraces are a common landform along the California coastline. Marine terraces record a unique combination of stable sea level high stands preserved by a tectonically uplifting landmass. During a stable sea level period, high energy waves cut into and drive back sea cliffs resulting in a broad slightly seaward dipping wave cut platform. Wave cut platforms are preserved as marine terraces when sea level changes relative to the wave cut platform. Relative sea level change can be achieved by tectonic uplift or eustatic sea level fall. We discuss the processes that create, preserve, and alter marine terraces as well as present evidence for five periods of stable sea stands during the past ~400,000 years which correspond to periods of stable sea level and are superimposed on the tectonically rising Santa Cruz Island.