Page 28 - AT

A28 SCIENCE
Friday 7 September 2018

In this July 2, 2018, photo, traffic moves on the old Gerald Desmond Bridge next to its replacement
bridge under construction in Long Beach, Calif.
Associated Press
New California bridge gets sensors

Researchers use DNA to gather earthquake data

to ID shark tooth CHRISTOPHER WEBER The eastern span replace- California. Cable-stayed
bridges are distinct from
LONG BEACH, Calif. (AP) ment of the San Francisco-
taken from boy's leg — A replacement bridge Oakland Bay Bridge that more common suspen-
under construction at the opened in 2013 has more sion bridges in that the
main span deck is entirely
second-busiest port in the than 200.
U.S. isn't just a crucial route But the building of the new supported by cables con-
ISLIP, N.Y. (AP) — A tooth ten. Both children were for cargo trucks and South- Long Beach span, south nected to the twin 515-
taken from the leg of a treated and released ern California commuters of Los Angeles, marks the foot (157-meter) towers.
boy bitten at New York's from a hospital. The girl re- — it's a concrete-and-steel first time the sensors have It makes for a particularly
Fire Island National Sea- ported seeing an orange- science experiment for en- been incorporated into sturdy design that's been
shore has been identified brown fish 3 feet to 4 feet gineers and seismologists. the design of a California tested to withstand power-
as that of a sand tiger long with a dorsal fin. The new bridge, which will bridge from Day One, said ful earthquakes or a terror-
shark, after a DNA com- Lindsay French, program stretch 8,800 feet (2,680 Duane L. Kenagy, an engi- ist bombing.
parison, researchers an- manager for the shark re- meters) over the Port of neer and the port's interim "You just can't knock one
nounced Wednesday. search center, arranged Long Beach, is being built deputy executive director. of these things down by
University of Florida re- for the tooth to be sent to with about 75 seismic sen- The original bridge has tak- knocking out one or two
searchers compared DNA the researchers for DNA sors that will measure the en a "pretty good beating" cables," Parrish said. The
from the tooth to a genet- analysis. Naylor believes forces imparted on the since it was built in 1968, Ke- design, popular in Asia and
ic dataset of sharks to de- both bites were acciden- span when one of several nagy said. Evidence of that parts of Europe, is catching
termine its species. Gavin tal, from juvenile sharks nearby faults set off an is the netting — called "dia- on in the U.S. as larger con-
Naylor, director of the following schools of fish. earthquake. It will replace pers" — recently placed un- struction machinery and
Florida Program for Shark "Perhaps incorrectly, I'm the Gerald Desmond derneath to capture hunks new high-tech materials
Research at the Florida putting these in the bin Bridge, though it's unclear if of concrete that regularly make them cheaper and
Museum of Natural History of naive young sharks," it will retain that name. break away. The roadway easier to build.
in Gainesville, said it's the Naylor said. "I'm sure the The new bridge is due to is "reaching the end of its Designed to last 100 years,
first time a shark involved children who were bit- open next year. natural life" but is consid- the new bridge has a high-
in a bite has been identi- ten were petrified, but "New bridges don't come ered safe for traffic until the er clearance for larger car-
fied using DNA. the sharks probably were, along very often, so it's ex- new bridge opens, he said. go ships and elastic "points
Beaches were closed at too." He said sand ti- citing," said Dr. John Par- About 15 percent of all of isolation" that enable
Fire Island in mid-July after gers can grow up to 500 rish, head of the Califor- containerized cargo enter- segments to move inde-
the 13-year-old boy and a pounds (226 kilograms) nia Geological Survey. His ing the U.S. travels over the pendently without damag-
12-year-old girl were bit- but rarely bite humans. q agency's Strong Motion In- span daily, and it's a key ing other sections. Joints
strumentation Program will artery for motorists travel- and bearings are designed
be among those crunching ing between the city of to break under stress and
the information the sensors Long Beach and San Pe- are easily replaceable to
capture. The data will be dro, a working-class wa- get the bridge reopened
added to the state's data- terfront neighborhood on quickly after a violent shak-
base of earthquake knowl- the southern edge of Los ing shuts it down.
edge. Angeles. The old bridge will be torn
California's bridges and Its nearly $1.5 billion re- down. It had no sensors,
other infrastructure have placement is historic for so seismologists and engi-
been outfitted with quake the built-in seismology and neers are eager for the in-
sensors called acceler- because it's the first cable- formation the new span will
ometers since the 1970s. stayed vehicle bridge in provide.q