Diving Between Continental Plates - Silfra Canyon, Iceland
The cathedral at Silfra canyon is a deep fault filled with fresh water in the rift valley between the Eurasian and North American tectonic plates at Thingvellir National Park, Iceland. The left side of the photo is the North American plate and the Eurasian plate is on the right. This “Earth void” combines fresh and salt water, hot springs, and uneven rock formations as a result of the plates constantly pulling apart from each other at a rate of one inch per year.
Photo by marine biologist and author Dr. Alexander Mustard