Aug 012011
 
Haloclines in Olwolgin Cave

About the site I’ve already talked about a couple of photos I’ve taken of unique features in the Roe Plains caves, including the Black and White Raft Room and the hanging roots. Cave diving in the Roe Plains provided the biggest photographic challenge I’ve experienced thus far – taking clear pictures in a graduated halocline. Haloclines occur where salty and freshwater meet, creating a mixing layer. Unlike the Mexican caves on the Yucatan Peninsula, the halocline in the Roe Plains caves runs at every level of the water. This means it isn’t possible to swim above it, and any diver movement through the cave mixes water of different levels of salinity. For those who haven’t dived in these conditions before, [read more…]

Jun 272011
 
Hanging Roots in Olwolgin Cave

  About the dive Olwolgin Cave is located on the Roe Plain, Western Australia, not far from Burnabbie Cave. As I posted previously, the Roe Plains caves are quite different from the white walled, blue water, big tunnels of the better known Nullarbor Plain caves. The first thing you notice is the yellowish tint to the water (but not to the walls) and the narrow, twisting, multilevel nature of the cave. With the water level close to the surface, tree roots from the desert above intrude into areas of the cave. However, the Roe Plains cave also have unique salinity characteristics. Instead of a single halocline with a distinct mixing zone between layers of fresh and salty water, like might [read more…]