Scuba divers have discovered a primeval underwater forest off the coast of Alabama.
The Bald Cypress forest
was buried under ocean sediments, protected in an oxygen-free
environment for more than 50,000 years, but was likely uncovered by Hurricane Katrina
in 2005, said Ben Raines, one of the first divers to explore the
underwater forest and the executive director of the nonprofit Weeks Bay
Foundation, which researches estuaries.
The forest contains trees so well-preserved that when they are cut, they still smell like fresh Cypress sap, Raines said.
The stumps of the Cypress trees span an area of at least 0.5 square
miles (0.8 kilometers), several miles from the coast of Mobile, Ala.,
and sit about 60 feet (18 meters) below the surface of the Gulf of
Mexico.
Despite its discovery only recently, the underwater landscape has just a
few years to be explored, before wood-burrowing marine animals destroy
the ancient forest. [8 of the World's Most Endangered Places]
Closely guarded secret
Raines was talking with a friend who owned a dive shop about a year
after Hurricane Katrina. The dive shop owner confided that a local
fisherman had found a site teeming with fish and wildlife and suspected
that something big was hidden below. The diver went down to explore and
found a forest of trees, then told Raines about his stunning find.
But because scuba divers often take artifacts from shipwrecks and other
sites, the dive shop owner refused to disclose the location for many
years, Raines said.
In 2012, the owner finally revealed the site's location after swearing
Raines to secrecy. Raines then did his own dive and discovered a
primeval Cypress swamp in pristine condition. The forest had become an
artificial reef, attracting fish, crustaceans, sea anemones and other
underwater life burrowing between the roots of dislodged stumps. [Images: Mysterious Underwater Stone Structure]
Some of the trees were truly massive, and many logs had fallen over
before being covered by ocean sediment. Raines swam the length of the
logs.
"Swimming around amidst these stumps and logs, you just feel like
you're in this fairy world," Raines told LiveScience's OurAmazingPlanet.
Primeval forest
Raines reached out to several scientists to learn more about the
forest. One of those scientists was Grant Harley, a dendrochronologist
(someone who studies tree rings) at the University of Southern
Mississippi.
Harley was intrigued, and together with geographer Kristine DeLong of
Louisiana State University, set out to discover the site's secrets.
The research team created a sonar map of the area and analyzed two
samples Raines took from trees. DeLong is planning her own dive at the
site later this year. Because of the forest depth, scuba divers can only
stay below for about 40 minutes before coming up.
Carbon isotopes (atoms of the same element that have different
molecular weights) revealed that the trees were about 52,000 years old.
The trees' growth rings
could reveal secrets about the climate of the Gulf of Mexico thousands
of years ago, during a period known as the Wisconsin Glacial period,
when sea levels were much lower than they are today. [World's Weirdest Geological Formations]
In addition, because Bald Cypress trees can live a thousand years, and there are so many of them, the trees could contain thousands of years of climate history for the region, Harley said.
"These stumps are so big, they're upwards of two meters in diameter —
the size of trucks," Harley told OurAmazingPlanet. "They probably
contain thousands of growth rings."
The team, which has not yet published their results in a peer-reviewed
journal, is currently applying for grants to explore the site more
thoroughly.
Harley estimates they have just two years.
"The longer this wood sits on the bottom of the ocean, the more marine
organisms burrow into the wood, which can create hurdles when we are
trying to get radiocarbon dates," Harley said. "It can really make the
sample undatable, unusable."
No comments:
Post a Comment