UW-Oshkosh students explore caves and island hydrology:
The group swimming in Grotto Bay cave. The water is fresh and cold at the surface, but warm and salty below. The cold water is a fresh water lens supplied by rain that floats on seawater fed by passages to the ocean. Our water tests showed high phosphorus and nitrogen levels in this cave. |
Jodi bravely stepping into the cave water; she found that it was cooler (about 60 degrees F) than the seawater outside. |
Joe following Jodi into the cave water. He found that the water was warmer--perhaps due to mixing of the fresh water and seawater--or does it have something to do with that high nitrogen concentration that we found later? |
The group swimming in a large room within Walsingham Cave. We had a tour of Walsingham Park and swam in a large sinkhole nearby. |
Stalactites and red iron-oxide-stained terra rossa paleo-soil in Fantasy Cave. You can see stalagmites under the seawater here where they represent a "fossil" vadose zone. The tidal range in the cave is about 1.0 meters! |
Massive stalagmites in Fantasy Cave. These are on their way to joining up with the overlying stalactites and will form pillars eventually. |