Iceberg off Miami? Did icebergs drift off Florida coast?
A new scientific study suggests that 50 meters wide and 5 meters troughs found in the sea floor off the central Florida Keys were made by drifting icebergs.
As the last ice age waned and climate warmed, immense lakes of glacial meltwater that accumulated behind natural ice dams occasionally burst forth from the mouth of Canada’s Hudson Bay and the Gulf of St. Lawrence.
When those iceberg-laden outburst floods—some of them carrying more than 1 million cubic meters of water per second and lasting several months—reached the open sea, they took a right turn and flowed south along the coast as far as the Florida Keys, a new study suggests.
The torrent-driven icebergs, some of them hundreds of meters thick, plowed troughs in the sea floor all along the continental shelf. Some have already been discovered off the coast of South Carolina (from lower left to top center of the image).
Whereas the troughs off South Carolina measure up to 100 meters across and 20 meters deep, those off the central Florida Keys typically are no more than 50 meters wide and 5 meters deep and lie less than 12 kilometers offshore.
This is as expected, because the icebergs would have melted to smaller size as they drifted south.