203
Surprising Discovery
As the results of the analyses filtered in, a picture of the past began to unfold. Think
of it as translating text from a foreign language – the meaning of the text isn’t understood right away but is revealed as words and sentences are deciphered. This is
always an exciting phase of the work but this time the early results from our island
cores surprised us. A major shift in the coastal environment appeared to happen in
less than 200 years! What do I mean by major? If you had been standing at the locations of our four islands about 3500 years ago, you would have been in the mangrove forest of southern mainland Florida. The coastline extended much farther out
than it does today. This information was not new because many previous researchers
have reported on these changes in the position of the shoreline. What surprised us
was the rate and timing of the change. The land had turned into an estuary in less
than two hundred years, but here is the part that really got our attention – between
about 4200 and 2800 years ago when this change took place, the rates of relative
Fig. 12.11 Collecting
cores on Buttonwood Key,
Florida Bay, one of the
four islands we studied, in
April 2014. (Image by
G.L. Wingard)
12 Climate, Sea Level, and People – Changing South Florida’s Mangrove Coast
Surprising Discovery
As the results of the analyses filtered in, a picture of the past began to unfold. Think
of it as translating text from a foreign language – the meaning of the text isn’t understood right away but is revealed as words and sentences are deciphered. This is
always an exciting phase of the work but this time the early results from our island
cores surprised us. A major shift in the coastal environment appeared to happen in
less than 200 years! What do I mean by major? If you had been standing at the locations of our four islands about 3500 years ago, you would have been in the mangrove forest of southern mainland Florida. The coastline extended much farther out
than it does today. This information was not new because many previous researchers
have reported on these changes in the position of the shoreline. What surprised us
was the rate and timing of the change. The land had turned into an estuary in less
than two hundred years, but here is the part that really got our attention – between
about 4200 and 2800 years ago when this change took place, the rates of relative
Fig. 12.11 Collecting
cores on Buttonwood Key,
Florida Bay, one of the
four islands we studied, in
April 2014. (Image by
G.L. Wingard)
12 Climate, Sea Level, and People – Changing South Florida’s Mangrove Coast