(hit on image to enlarge it)Someone asked the blog if Key Biscayne was on bedrock and about flooding (see Post 10/05). I asked John Van Leer Sc.D., a member of the Miami-Dade Climate Change Advisory Task Force - Science Committee, and here is the Geology lesson:
Most of the City of Miami (Ft. Lauderdale and Palm Beach) is located on a coastal ridge made of oolitic limestone which is a soft and extremely porous rock laid down during the last interglacial period about 125,000 years before present when sea level was about 25' higher than present. Thus the highest parts of this ridge are about 25' above present sea level. There are channels through the ridge which were called glades in the old days which gives the Everglades its name and have drainage canals dug in them. These glades were tidal channels through the sand bank which became solidified as the coastal ridge.
Once sea level dropped during the subsequent ice age, the ooids cemented together to form oolitic limestone we see today. Flagler's FEC Railroad was built down the highest part of the coastal ridge so it will be least likely to flood and the cities which grew up along his railroad are also on the highest ground.
4 comments:
The Sea Level was 25 feet higher 125,000 years ago. Those frikin' Cave Men and their damn Hummers must of caused it.
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You must mean "must have caused it"...
We are overbuilt in the coastal ridge, that is why they are building out West in neighborhoods that are sure to flood.
Swamp + cement that hardens under water = Western Dade County
That is all the commission needs to know on their planning documents.
Of course, it would really help the commissioners and their friends if the SFWMD would stop pumping water into the county/Everglades. We would be happy to bath in our swimming pools and drink bottled water, as long as we get more houses built.
Don't forget to thank Mario Diaz Balart and certain commissioners who love to help West Kendall with transit issues.
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