The effects of climate change are far reaching - what changes can you see today?
While you’re here, there are some key observations we ask that you submit before logging the site. Please submit these in the message center or to: nps_ever_science_comms@nps.gov. Read the text below for more information.
- Look at the photo provided in the cache images and below, then look out to the southeast at “south beach”. Has the shape of the beach changed? If so, in what way?
- Is there a way that wave energy could help protect Fort Jefferson and the surrounding historical structures?
- Please take a photo from the EarthCache roughly in each of the 4 cardinal directions (North, East, South, West) and submit these.
Wind-driven ocean waves can create islands by moving sand, rubble, and mud. The islands of the Dry Tortugas were created this way. But this wave energy can also destroy. Water slapping into an object day in and day out will eventually wear it down. This is what causes coastal erosion. The bigger the waves, the more energy they transfer to the shoreline, and the more erosion occurs. During storms, especially strong storms like hurricanes, wave energy can completely change a shoreline.
In undeveloped areas, there are often natural features that protect shorelines from damaging waves. These include sand dune vegetation, mangrove trees, and even offshore coral reefs. Unfortunately, if no natural features like this exist, human developments close to the shore are vulnerable to succumbing to coastal erosion.
Back in the mid-1800s, when Fort Jefferson was being constructed, engineers devised a way to protect the fort itself from the ravages of the sea. That engineering feature is the moat wall you are standing on now. The moat wall, also called the counterscarp, takes the beating so the fort doesn’t need to. Of course, during severe storms, the moat wall can be breached and it has been damaged and repaired many times.
Unfortunately, South Florida and the Florida Keys are at a heightened risk for the strongest storms there are, hurricanes. The region juts out into the warming ocean waters of the Atlantic, Caribbean, and Gulf of Mexico making it extremely vulnerable to the effects of climate change on these storms, which include damaging winds and storm surges from increasingly frequent and/or more intense tropical storms and hurricanes.
People have lived in and put their mark on this region for thousands of years, including in Dry Tortugas National Park, which is bursting with historical structures and artifacts. Unfortunately, sea level rise and climate change are threatening or even damaging these historical structures and artifacts at increasingly destructive rates.
The sandy keys of the Dry Tortugas have always been shaped by the waves. However, normal erosion has been accelerated by sea level rise and more frequent or more intense storms. If you look at the end of the South Coaling Dock to the south, you can see the effect of shoreline erosion collapsing the dock walls.
Information on getting to Dry Tortugas National Park can be found on the park website. Please be aware that there is no cell phone signal or public wifi available in Dry Tortugas National Park and players should plan accordingly.
Please Note: this EarthCache has been developed by Everglades National Park for the enjoyment of visitors. The placement of caches on lands managed by the National Park Service and the U.S. Fish and Wildlife Service remains generally prohibited. The placement of any new cache requires advance written approval from the park.