Canary in a Coalmine

I simply love to walk along the seashore in winter.

The Great Blue Hole is a large underwater sinkhole off the coast of Belize that’s more than 1,000 feet wide and 400 feet deep. It formed as a limestone cave system during the last ice age when sea levels were lower, and the caves flooded as the planet warmed and sea levels rose. Jacques-Yves Cousteau made the site famous in 1971 when he declared it one of the top 10 scuba diving sites in the world, and today it is a World Heritage Site.
13 amazing sinkholes

 (source mothernaturenetwork)