Welcome to Seal Beach
Located along the northern edge of Orange County’s coastline, the Seal Beach coastal dunes represent one of the few remaining natural dune ecosystems in Southern California. These sandy ridges form a crucial barrier between the Pacific Ocean and the city behind them. This EarthCache invites you to explore how wind, waves, vegetation, and coastal processes combine to shape and protect this rare habitat.
What Are Coastal Dunes?
Coastal dunes form when wind transports dry sand from the beach and deposits it inland. The sand begins to accumulate wherever something interrupts the wind, often shells, driftwood, or the first hardy plants able to survive here. Once vegetation takes hold, its roots stabilize the sand, which allows dunes to grow taller and wider. Dunes usually develop in a series of ridges that can shift over time as storms, seasonal winds, and changes in sea level reshape the coastline.
These dunes serve as a natural defense system. They absorb the impact of storm waves and help prevent flooding of inland communities. Vegetation plays a major role in trapping and holding sand. Plants like beach evening primrose and sand verbena tolerate salty winds and dry conditions, creating habitat for birds, insects, and other wildlife. Without these plants, the sand would blow away, leaving the coast more vulnerable to erosion and storm surge.
Seal Beach’s dunes are especially important because much of Southern California’s dune habitat has been destroyed by development. Although human activity has reduced the size and mobility of the dunes, conservation efforts help protect the habitat that remains. When you explore this site, you are walking through a dynamic geological feature that continuously responds to wind, tides, and the forces of the ocean
.
Tasks for This EarthCache
To log this EarthCache, visit the site and complete the following tasks. Send your answers via Geocaching or email.
-
Include "Coastal Dunes - Seal Beach - GCBEGHN" on the first line of your message.
-
Estimate the average height of the dunes and describe how steep their sides appear. Based on your observations, do these dunes seem mature and well-established or smaller and still developing?
-
Observe the shape of the dunes. Are they arranged as long ridges parallel to the shoreline or more irregularly? Based on what you see, what do you think is the primary natural force moving and shaping the sand in this area?
-
Look closely at the plants growing on the dunes. How do you think the vegetation helps hold the sand in place? What evidence can you find of roots or plants trapping sand?
-
Examine the dunes for footprints, tire tracks, fences, or signs of vegetation loss. How might human traffic affect dune stability?
-
In your log, attach a photo of yourself or a personal item with the dunes in the background. (Note: photos predating the publication of this EarthCache are not accepted.)