Dune Day!

The best part about Hatfield was Dune Day, which we have been waiting for since day 1. Dune day started with a 3 hour drive out past Florence and a two mile hike across the dunes. The weather was awesome, but sand was still biting at our heels the entire way! For most of the trek we goofed around by jumping off of the crests of the dunes. This is also a great photo because you can see a lot of the changes that Oregon dunes gone through in recent years. Dunes used to be fairly fluid, with constantly moving sands, until the introduction of European dune grass. European dune grass was introduced on the Oregon coast to prevent sand from blocking river channels and roads. Unfortunately, it spread further than intended and disrupted sand movement across the Oregon Coast. At first it seems like it wouldn't be that important if the sand were not in motion, but because the movement of the sand was stopped, plants in addition to the dune grass were able to take hold. Today the forest and plants encroaching on the dunes invade an additional 22 feet of dune per year and with them bring a multitude of other organisms that wouldn't regularly be found in the dunes.

On our way to the coastline, we were still able to study the some of the original features of the dunes as well as some of the new ones. We saw these backwards, but it would probably make more sense if I described them to you from the coast to the forest. The first dune you come across when leaving the ocean is called a foredune, this is a low dune parallel to the water's edge. The dune is usually 20-30 feet high and is made of driftwood and sand. Today it is topped with dune grass (stabilizing it, remember?), which eliminates the ability of the dune to allow a natural sand source for the dunes behind it.


The next feature behind this dune is a series of hummocks, which are small mounds of sand formed around vegetation. Because sand is no longer supplied by the foredune and wind blows away the sand behind it, the next feature is a flat plain behind the foredune. This plain is called the deflation plain, where the sand has been stripped down to the wet sand underneath, and where even more vegetation thrives! Northwestern winds create a series of transverse dunes behind these which are formed perpendicular to the wind and typically crest at 5-20 feet high.


Once we got to the coastline we all dove into the Pacific, which was insanely cold!! Even though it is summer, this time of year we have upwelling on the Oregon coast so all the cold water from the bottom of the ocean is brought up to the surface. We dove under a few waves and then raced for the beach to get our core temperatures back up. Wren's fingers were white a lot longer than they should have been, but we got her warmed back up before we headed back over the dunes. Here is a picture of us huddling together to get warmed back up again.