Page 28 - aruba-today-20180915

A28 SCIENCE
Saturday 15 September 2018

AP Explains: How hurricanes unleash lethal storm surges

By SETH BORENSTEIN the right-front quadrant of
WASHINGTON (AP) — a storm because the sys-
Behold the awesome tem's counterclockwise
power of water. Already motion pushes more wa-
the ocean is swallowing ter inland, Masters said.
beaches, roads and any- Sometimes in the opposite
thing else in the way of Hur- quadrant there's a reverse
ricane Florence's monstrous storm surge that makes
storm surge. Storm surges the ocean retreat. That's
aren't walls of water, like particularly dangerous be-
a tsunami, as commonly cause the ocean comes
thought. Caused by a hur- back quickly with 6 feet (2
ricane's winds pushing re- meters) or more of water.
lentlessly on the shore, they Storm surge is higher when
are more like domes of the water just off the beach
high water that form as the is shallower, Needham
ocean spreads inland. The Waves slam the Oceana Pier & Pier House Restaurant in Atlantic Beach, N.C., Thursday, Sept. 13, said. Think of it like a giant
high water has destructive 2018 as Hurricane Florence approaches the area. aquarium filled to the brim.
waves on top, and it comes Associated Press If a large rock in thrown
in addition to normal tides. in, it spills over. But if the
"You are taking the ocean "These bays, these rivers the National Oceanic and ment aid, he said. aquarium is not full, it's only
and raising it," said storm and these inlets, there's so Atmospheric Administra- Needham, who drove all a ripple.
surge expert Hal Need- much storm surge the wa- tion announced . It was the night from Miami to North Tides are another factor.
ham, director of Marine ter is being literally forced first year that the hurricane Myrtle Beach, South Caro- The surge is highest when
Weather and Climate in to flow the opposite direc- center had started new lina, to watch and record the tides are high. The
Miami. "It's not a wave the tion," Graham said. "You storm surge warnings. Most- the storm surge from the coast of the Carolinas is
surfer rides. It's actually rais- can get storm surge even ly people are getting better relative safety of a park- about middle of the road
ing the ocean. That's why several miles inland." at evacuating, with three- ing garage, said the storm with about 4 to 5 feet of
it's so scary." While hurricane-force quarters of the Florida Keys surge had "already gob- difference (1.2 to 1.5 me-
Florence's storm surge will winds can rip the roofs off fleeing before Irma, Mas- bled up the beach" there. ters) between high and low
probably be 7 to 11 feet houses, it is the water — ters said. "It's just going to be an inter- tides.
(more than 2 to 3 meters) storm surge, inland flood- Storm surge is also the esting ride," Needham said. The shape of the coast-
above ground in parts of ing, surf and drowning at source of vast amounts "I could not sit home and line is another factor. If it is
North Carolina, according sea — that kills nearly 9 out of damage. Masters es- watch it on TV. I had to be bowl-shaped, like in Geor-
to the National Hurricane of 10 people in hurricanes timated that storm surge there." gia and South Carolina, the
Center. Other areas can like Florence. caused at least $3 billion in The worst storm surge surge is deeper, but when it
expect the surge to be tall- And of all those, storm damage, compared with comes in with a hurricane's is the opposite shape, like
er than the average person surge is the deadliest. From maybe $1 billion for wind eye, and it arrives "with a lot the Outer Banks, it's less so,
— nearly 6 feet (2 meters) 1963 to 2012, 49 percent of damage. Damaged or de- of debris to batter you, and Needham said.
or higher. U.S. hurricane deaths were stroyed buildings are often it's not particularly surviv- Seas have risen from global
Even if a house is elevated from storm surge, 27 per- rebuilt in the same surge- able," Masters said. warming, making all of this
10 feet (3 meters), with that cent from rain, 8 percent prone areas, with govern- Storm surge is higher in even worse. q
kind of storm surge, "there's from wind, 6 percent from
a good chance there's go- surf, 6 percent were off-
ing to be water inside of it," shore and 3 percent from Truly deep: Florence to dump
Needham said. tornadoes, according to a
With Florence moving slow- National Hurricane Center
ly and stalling, the storm study . 18 trillion gallons of rain
surge is going to be a big- The deadliest hurricanes
ger, longer-term factor to hit the U.S. mainland
than normal because the killed most of their victims By SETH BORENSTEIN year's Harvey in Texas and 3,800 feet (1.1 kilometers)
water "just keeps piling up," with storm surge, includ- WASHINGTON (AP) — Flor- Louisiana because the 2017 of water, more than twice
Needham said. ing 2005's Katrina, said Jeff ence's rain total will likely storm stalled longer and as high as the island's tallest
It's not just beach areas Masters, meteorology di- be staggeringly huge. stayed closer to the Gulf of building, One World Trade
that are at risk. Storm surge rector at Weather Under- Meteorologist Ryan Maue Mexico for more moisture. Center.
invades rivers and estuar- ground. of weathermodels.com Florence still should swamp North Carolina alone is
ies, too. And National Hur- But last year, even with hur- calculates that Hurricane the 5.2 trillion gallons that forecast to get 9.6 trillion
ricane Center Director Ken ricanes Harvey, Irma and Florence is forecast to fell 19 years ago when gallons of rain, enough to
Graham said that's a par- Maria, no one in the United dump about 18 trillion gal- Floyd was the last scary cover the Tar Heel state in
ticular worry with Florence. States died of storm surge, lons of rain over a week storm to hit the Carolinas. about 10 inches (25 centi-
over the North Carolina, Florence's 18 trillion gallons meters) of rain.
South Carolinas, Virginia, is as much water as there is Maue calculates that 34
Georgia, Tennessee, Ken- in the entire Chesapeake million people in the U.S.
tucky and Maryland. It Bay. It's also enough to cov- are forecast to get at least
doesn't include rain after it er the entire state of Texas 3 inches (7.6 centimeters)
dissipates and its remnants with nearly four inches (10 of rain from Florence, with
circle back to the north- centimeters) of water. more than 5.7 million prob-
east. That much rain is 2.4 trillion ably getting at least a foot,
Those numbers still don't cubic feet (68 billion cubic and about 1.5 million get-
quite measure up to the meters). It's enough to cov- ting 20 inches (51 centime-
25 trillion gallons from last er Manhattan with nearly ters) or more.q