Note: This is a locationless geocache. Instead of finding a box, you're going on a quest to locate a meromictic lake. You'll have to do a little research to find out exactly where, and how many, there are. We hope you'll learn a bit of earth science along the way.
Please begin your journey by reading the following description of meromictic lakes from The Geology Guide at About.com. He uses Round Lake as an example, which is where we began our own journey to create this locationless geocache for you:
"Round Lake, near Syracuse, New York, is an example of a meromictic lake, a lake whose waters do not mix. Because the rocks around it contain beds of salt, its bottom waters are a layer of strong brine. Its surface waters are devoid of fish, instead supporting an unusual community of bacteria and algae that give the water a peculiar milky blue-green color. Because its bottom is so stable, the sediments that accumulate on the floor of Round Lake are exceptionally well-preserved records of the plant species growing in the region as well as the changing aquatic community in the surface layers. Geographically, it sits on the border between two great weather systems separated by a jet stream in the upper atmosphere. This makes it very sensitive to subtle climate changes that have occurred during the last 10,000 years since the glaciers left. Round Lake is preserved in Green Lakes State Park. Most lakes in the temperate zone turn their waters over every winter as the water cools. Water reaches its greatest density at 4 degrees above freezing, so it sinks when it cools to that temperature. The sinking water displaces the water below, no matter what temperature it's at, and the result is a complete mixing of the lake. The freshly oxygenated deep water sustains fish throughout the winter even when the surface is frozen over.
Three local students wrote a report on the geological aspects of Green Lakes State Park, highlighting the two meromictic lakes. Let's give them a big round of applause!
"During the last glacial retreat about 10,000 years ago, lakes were formed from melt water plunge pools. Green Lakes is 195 feet deep and Round Lakes is 180 feet deep. Both Green and Round Lakes are meromictic lakes. Most lakes experience seasonal turnovers, where the bottom and top waters mix. In a meromictic lake the water on the top doesn't sink to the bottom and mix. The bottom waters always stay the same. Because of this the bottom waters become poisonous. When the seasons change, the waters still stay the same. There are only 11 meromictic lakes in the United States. In 1975 Round Lake, so named because of its unique round shape, was designated a National Natural Landmark by the U.S. Department of the Interior." - by Stephanie H., Zachary C. & Jessica O.
You can read about Soap Lake,
an extreme example of a meromictic lake, to learn more about this unique geological system. Soap Lake is located in the center of Washington State, twenty miles north of Interstate-90, between Seattle and Spokane.
Ballston Lake, north of Albany, New York, was missed during a USGS attempt to identify meromictic lakes. Here's a clip from the Ballston Lake Initiative program at the Environmental Studies Program at Union Colllege:
"Meromictic Lakes are ideal for paleolimnological (ancient history of lakes) studies because of lack of bioturbation (churning of sediment by bottom-dwelling organisms) in sediments and highly predictable deposition characteristics (Anderson, et al., 1985). Meromictic lakes are chemically interesting for the study of speciation of redox-sensitive elements across the chemocline (e.g., Viollier, et al., 1995) and biologically interesting because intense bacterial blooms can occur at the chemocline (Overmann, et al., 1996) and biologic zonation results from the stratification, including prey, such as freshwater shrimp, that use the chemocline as a defense against predation. Meromictic lakes are most notorious, however, for abrupt releases of dissolved carbon dioxide, methane, and other gasses. This abrupt release occurred recently in Lake Nyos in Africa, but in this case, the lake sits atop a volcanic vent (Kling, et al., 1994). In an attempt to survey all meromictic lakes in North America, the U.S. Geological Survey (Anderson, et al., 1985) was only able to identify about 160 lakes - and overlooked Ballston Lake."
Click here for more information about Green Lakes State Park. If you'd like to visit two of the three meromictic lakes that can be found in Central New York, you can start at the Green Lakes State Park office at N43 3.503, W75 58.277. Pick up a free trail map there.
Please follow these rules to log this locationless geocache:
1. Use your GPS receiver to mark the location of a meromictic lake. Round Lake & Green Lake at Green Lakes State Park were used as the cache model, so consider them to be logged. Soap Lake and Ballston Lake may still be logged. With a little research, you'll find other meromictic lakes all over the world. You must be able to show that your lake has been officially determined to be meromictic. That fact may be confirmed with a photo of a sign, or with a link to a website. The coordinates used in your log must be for a specific and significant location at the lake, such as an official sign, park office, or some other physically permanent structure. In other words, a visitor should be able to find that object with a GPS receiver on any day of the year. Please don't use a common or moveable item like a tree or a rock.
2. Take a photo of the site that shows you and your GPS receiver at the spot where you mark the coordinates for your log report. One or two additional photos showing the surroundings will greatly enhance your report! The photos linked below will serve as examples.
3. Submit a log report that includes the coordinates and some descriptive information. Describe the actual location, naming the nearest city, as well as the state and country. The goal here is to share information about meromictic lakes, so take time to do a little research. Give us a paragraph or two that describes your visit, as well as the lake itself. Try to find at least one website with information about your lake, and include the link in your log report.
4. Then immediately upload the required confirmation photo in order to log this cache as found. The usual locationless cache rules apply: one log per geocacher, and each location may be logged only once. Please read all the logs to be sure your lake hasn't already been reported. All photos must be originals, and logs without GPS photos will be deleted.