January 6, 2011

Sand Structures at Nobska Beach

Posted by Evelyn Mervine

Nobska sands 1, Woods Hole, December 2010.

Last week my fiance and I went for a long walk around Woods Hole, the village on Cape Cod where I live. On this walk, we stopped at Nobska Beach, a pretty little beach with a view of Martha’s Vineyard. There were footprints everywhere, so clearly others (two-legged humans and four-legged canines) had recently taken a winter beach stroll at Nobska. In the summertime, the beach is usually packed with locals and tourists. When we visited the beach last week, however, it was deserted. We walked along looking at the pretty views of the lighthouse and Vineyard. Soon, however, we became more interested in the sands at our feet than the views above.

This is because we noticed some interesting structures in the beach sands. Wherever little tufts of vegetation grew out of the sand, miniature sand deposits built up. These structures are formed by the wind, as the diagram below shows. Note that I took the diagram below from this site about sediment transport by wind.

Figure taken from here.

In the Nobska Beach structures, the vegetation is acting as the barrier. The wind (blowing primarily to the southeast, I believe) creates little mini sand structures all over Nobska Beach.

Nobska sands 2, Cape Cod, December 2010.
Nobska sands 3, Cape Cod, December 2010.

I never noticed these structures during my summer visits to Nobska Beach. Perhaps the winter winds make them more predominant or– more likely– they are trodden down by hundreds of summer visitors.

Here’s a picture of pretty Nobska Lighthouse, all decked out for the holidays:

Nobska Lighthouse, Cape Cod, December 2010.

And here are some Google Earth images showing you where Nobska Beach (yellow pushpin) and Nobska Lighthouse (red pushpin) are located. Click on the images below for a larger version.