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Since February, geoscientists using ground penetrating radar (GPR) for everything
from finding lost utilities to inspecting highways and bridges have been waiting
for some assurance from the Federal Communications Commission (FCC). Under a
controversial new set of rules for ultra-wideband technology, the FCC restricted
GPR usage to specific groups: law enforcement, fire and rescue organizations,
scientific research institutions, commercial mining companies and construction
companies (Geotimes, July 2002). Some of the waiting is now over as the FCC
adopted an Order on July 12 that allows GPR users to apply for a blanket waiver
to continue wide usage of GPR devices.
The FCC says that the new waiver procedure will provide an easy process for
old GPR systems to comply with the new regulations. The Order clarifies that
GPR users need not work for one of the groups stated in the original rules,
as long as their purpose falls under one of those categories. For example, an
independent geoscientist could legally use GPR to locate archaeological finds,
even if that geoscientist does not work for a scientific institution. “These
actions will permit the accommodation of existing products while ensuring that
the authorized radio services are protected from harmful interference and that
all new equipment complies with the appropriate standards,” says the FCC
Order.
However, the new Order alleviates only some concerns of the GPR community. “People
have started filing for waivers, but the turnaround time is expected to be 15
working days, so no one has an answer yet,” says Gary Olhoeft, a geophysics
professor at the Colorado School of Mines.
The geoscience community also worries, Olhoeft says, that the FCC and the National
Telecommunications and Information Administration (NTIA), who are handling the
waivers, do not have enough staff to quickly process the requests. Also unclear
is whether or not a waiver carries an expiration date. Moreover, Olhoeft points
out that the waivers do not cover GPR manufacturers and no one knows how long
it will take to develop a certification process that will allow the selling
of equipment again.
While these questions still loom around the GPR controversy, the waiver process
goes on. The application deadline for the FCC waiver is Oct. 15.
Contact the FCC for more. To read more about
the GPR rulings, link to the July story, Narrowing
the radio spectrum for geoscience.
Lisa M. Pinsker
A 110-million-year old pterosaur skull is generating interest in the paleontological
community. Writing in the July 19 Science, Brazilians Alexander Kellner from
the National Museum/Federal University and Diogenes de Almeida Campos from the
Museum of Earth Sciences in Rio de Janeiro say they’ve discovered a pterosaur,
Thalassodromeus Sethi, with the largest crest — three-fourths the size
of the skull — and a unique scissors-like jaw.
“It’s a very unusual skull, even for a pterosaur. There’s a very
large, thin and quite fragile crest. And the unusual jaw suggests specialization.
It just demonstrates how bizarre pterosaurs are,” says Christopher Bennett,
a paleontologist from the University of Connecticut.
Pterosaurs are one of the earliest winged animals. Paleontologists continue
to debate how these creatures lived. “Once we are faced with a distinct
anatomy, we try to compare it with other living and fossil species. In our case,
the only animal that has such a scissors-like bill is the skimmer,” Kellner
says, referring to the modern avian genus, Rynchops. These birds skim over water
as they hunt for pelagic fish and crustaceans.
David Unwin, a paleontologist from the Museum of Natural History in Berlin,
questions this claim. “Skimmers don’t have pointed jaw tips, as shown
for Thalassodromeus, because this doesn’t work when the jaw is skimmed
through water. Skimmers have a rather blunt jaw tip, as also seen in Rhamphorhynchus
[another type of pterosaur, hypothesized to be a skimmer], which helps direct
the water away to either side of the jaw as they skim.” Bennett has seen
the specimen and is also wary. “In cross-section the jaw is not laterally
compressed as is observed in skimmers,” he says.
But Kellner contends that the skull’s anterior is laterally compressed
and maintains the model is a strong one. “All arguments against this interpretation
would have to explain how a flying animal with a scissors-like beak would feed.”
He suggests that the scientific debate will be more on the function of the crest.
Not only is the crest large, but it is also embedded with the impression of
a network of blood vessels. “If this is correct — and there is nothing
else I could make of them — then the crest was extensively irrigated by
blood. Therefore we introduced the hypothesis that at least some pterosaurs
might have used their crest in thermal regulation,” Kellner says.
Unwin doubts this, claiming that in particular species the crest size can vary
from individual to individual: “Consequently, most pterosaur workers are
coming round to the idea that crests often show dimorphism — probably sexual
— and evolved primarily as signaling structures.” They may have had
other secondary functions, such as temperature control, but these are more controversial,
he explains.
While Bennett doubts the pterosaur was a skimmer, he believes that the interpretation
for temperature regulation is plausible.
Salma Monani
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