Scary Tsunamis


Narrator:
DECEMBER 26, 2004 — A MASSIVE TSUNAMI
IS SET ON A COLLISION COURSE ACROSS THE INDIAN OCEAN. WHEN IT SLAMS
INTO THE COASTLINE, THE FORCE OF THE WAVE WIPES ENTIRE COMMUNITIES
OFF THE MAP. EVEN TODAY,
IT’S HARD TO COMPREHEND THE SHEER DEVASTATION. Jaffe: IN INDONESIA, 150,000 OR SO PEOPLE
LOST THEIR LIVES. EVEN IN SRI LANKA, WHICH WAS MORE THAN
1,000 MILES AWAY, THERE WERE 36,000 PEOPLE
THAT LOST THEIR LIFE. ALL TOLD, ALMOST
A QUARTER OF A MILLION PEOPLE. Narrator: BRUCE JAFFE
IS A TSUNAMI EXPERT AT THE U.S. GEOLOGICAL SURVEY
IN SANTA CRUZ, CALIFORNIA. SOON AFTER THE WATERS RECEDED, JAFFE AND HIS TEAM
TRAVELED TO INDONESIA TO STUDY THE AFTERMATH WITH THE HOPE
OF BETTER UNDERSTANDING WHEN AND WHERE
OTHER BIG TSUNAMIS MAY OCCUR. TSUNAMIS ARE WAVES GENERATED BY ABRUPT, VERTICAL MOVEMENT
OF THE SEAFLOOR CAUSED BY EARTHQUAKES,
VOLCANIC ERUPTIONS, LANDSLIDES,
OR EVEN AN ASTEROID IMPACT. THIS ANIMATION SHOWS THE BIRTH
OF THE 2004 TSUNAMI WITH A MAGNITUDE 9.1 EARTHQUAKE DEEP WITHIN THE OCEAN FLOOR
OFF INDONESIA. Jaffe: HERE,
THE EARTHQUAKE IS PROPAGATING. AND THEN WHEN YOU PUT
THE WATER ON IT, ALL THE WATER DOES IS MIMIC
THE DEFORMATION ON THE SEAFLOOR. THAT CREATES THE TSUNAMI WAVE. Narrator: IN SOME PLACES,
THE RESULTING WAVE REACHES 100 FEET HIGH
WHEN IT STRIKES LAND. Jaffe: THIS VIDEO WAS TAKEN
IN BANDA ACEH, THE CAPITAL OF THE ACEH PROVINCE
OF SUMATRA. THE TSUNAMI
WAS MAYBE 30 FEET HIGH. IN THE OTHER PARTS OF SUMATRA
TO THE SOUTH, THE TSUNAMI WAS 100 FEET HIGH. Narrator:
SINCE THE SUMATRA TSUNAMI, SEVERAL OTHERS
HAVE WREAKED HAVOC. THIS DRAMATIC FOOTAGE
GRAPHICALLY ILLUSTRATES THE DEVASTATING POWER
OF THE TSUNAMI THAT HIT AFTER
THE 2011 JAPAN EARTHQUAKE. THE TSUNAMI KILLED 16,000 PEOPLE AND CAUSED A MELTDOWN AT THE
FUKUSHIMA NUCLEAR POWER PLANT. TSUNAMI WAVES RACED
ACROSS THE PACIFIC OCEAN AND HIT CALIFORNIA’S COAST
NINE HOURS LATER. THE SURGING WATER CAUSED
MORE THAN $50 MILLION OF DAMAGE TO SIX COUNTIES,
INCLUDING SANTA CRUZ, WHERE THE FORCE OF THE WAVES
SMASHED DOCKS AND BOATS. IN RESPONSE TO RECENT TSUNAMIS, THE CALIFORNIA GEOLOGICAL SURVEY AND STATE OFFICE
OF EMERGENCY SERVICES PARTNERED
WITH THE FEDERAL GOVERNMENT TO CREATE NEW MAPS THAT MODEL
THE POTENTIAL STRENGTH AND FLOODING FROM TSUNAMIS. THESE PLAYBOOKS
MAY HELP MINIMIZE DAMAGE TO CALIFORNIA HARBORS AND HELP COASTAL COMMUNITIES
UPDATE THEIR EVACUATION PLANS. TO PREPARE FOR TSUNAMIS, IT ALSO HELPS TO STUDY
THE CLUES THEY LEAVE BEHIND, WHICH SCIENTISTS CAN USE
TO TRACE THEIR ORIGINS AND ESTIMATE
WHEN THEY MAY STRIKE AGAIN. Jaffe:
AFTER THE WATER’S GONE AWAY, THE SAND IS LEFT BEHIND, AND SO IT’S A RECORD — IT’S A CALLING CARD,
IF YOU WILL, OF THE TSUNAMI. Narrator: BIG TSUNAMIS THROW
TONS OF SEDIMENT ONTO SHORE. THE LARGER GRAINS OF SAND
SETTLE FIRST WITH THE LIGHTER SEDIMENT
COMING TO REST AFTER. THIS CREATES A SAND LAYER THAT LEAVES
A TELLTALE TSUNAMI FINGERPRINT. Jaffe:
WHEN YOU FIND MULTIPLE DEPOSITS THAT WERE FORMED
MANY YEARS APART, YOU CAN START LOOKING AT
WHAT THE HAZARD IS IN AN AREA, ESTIMATING ON WHEN THAT AREA
MIGHT BE HIT AGAIN. Narrator:
SINCE A MAJOR TSUNAMI MAY ONLY STRIKE AN AREA
EVERY FEW HUNDRED YEARS, STUDYING THESE SAND DEPOSITS CAN HELP SPOT
POSSIBLE HAZARD AREAS WITH LITTLE OR NO RECORDED
TSUNAMI HISTORY. GOOD PLACES TO INVESTIGATE ARE
GEOLOGICALLY ACTIVE REGIONS, SUCH AS THE PACIFIC COAST
OF NORTH AMERICA. Griggs: THE PACIFIC IS SORT OF
ONE BIG HOT SPOT. WE’VE GOT TRENCHES ALMOST
COMPLETELY AROUND THE PACIFIC, AND IT HAS TO DO WITH
PLATE BOUNDARIES. Narrator: FOR HUNDREDS
OF MILLIONS OF YEARS, THE PLATES, OR ROCKY SLABS THAT MAKE UP
THE EARTH’S OUTER CRUST KNOWN AS THE LITHOSPHERE, HAVE MOVED AROUND THE GLOBE IN A PROCESS CALLED
PLATE TECTONICS. OVER TIME, THE PULLING APART
AND CRASHING TOGETHER OF PLATES FORMED THE CONTINENTS
AND OCEANS, AS WELL AS ISLAND CHAINS,
MOUNTAIN RANGES, AND OTHER FEATURES
AROUND THE GLOBE. SOMETIMES,
WHEN TWO PLATES COLLIDE, ONE IS PUSHED
UNDER THE OTHER, CREATING AREAS CALLED
“SUBDUCTION ZONES.” NORMALLY, PLATES MOVE
JUST CENTIMETERS PER YEAR. BUT OCCASIONALLY, THEY MOVE
RAPIDLY IN ONE LARGE SNAP. THIS VIOLENT MOVEMENT
CREATES BIG EARTHQUAKES. Griggs: IF YOU LOOK AT WHAT
HAPPENED IN THE INDIAN OCEAN, IT WAS 600 MILES LONG
AND 200 MILES DEEP. THAT WHOLE SLAB
HAS TO RIP AND BREAK. ONE SLAB
PULLING THE OTHER SLAB DOWN, AND IT REBOUNDS —
HUGE AMOUNT OF ENERGY. THAT’S A LOT OF WATER
TO DISPLACE. Narrator:
IT’S HARD TO PLAN FOR AN EVENT THAT MAY ONLY HAPPEN
ONCE EVERY 300 YEARS. BUT THE STATE OFFICE
OF EMERGENCY SERVICES AND NOAA, THE NATIONAL OCEANIC
AND ATMOSPHERIC ADMINISTRATION, HAVE ESTABLISHED
TSUNAMI HAZARD ZONES ALONG THE CALIFORNIA COAST. MORE THAN 6,000
TSUNAMI HAZARD SIGNS POSTED IN COASTAL AREAS HELP DIRECT RESIDENTS
TO HIGHER GROUND. Evans: TSUNAMIS DO OCCUR
ALONG THE COAST HERE. SAN FRANCISCO —
WE’VE HAD THEM IN THE BAY. SO YES, THEY ARE A REAL THREAT. THEY ARE RARE
TO HAVE DAMAGING TSUNAMIS, BUT WHEN THEY DO OCCUR, THOSE DAMAGING TSUNAMIS
CAN BE DEVASTATING. SO A WARNING SYSTEM IN PLACE
IS VERY NECESSARY. Narrator:
THE WARNING SYSTEM STARTS WITH NOAA’S
DEEP-OCEAN ASSESSMENT AND REPORTING
OF TSUNAMIS PROGRAM, OR D.A.R.T. Evans: WHAT WE HAVE HERE
IS THE D.A.R.T. SYSTEM — THE BUOY THAT SITS
ON TOP OF THE WATER. YOU HAVE THE PRESSURE SENSOR THAT WILL MEASURE THE PRESSURE
OF THE WATER ABOVE IT. IF IT PICKS UP
A LONG-PERIOD WAVE, BEING A POSSIBLE TSUNAMI, IT WILL THEN TRANSMIT
THE INFORMATION TO THIS BUOY, THE BUOY WILL THEN SEND IT
TO A SATELLITE, AND THEN THE SATELLITE SENDS IT
TO THE WARNING CENTERS. Narrator:
AFTER THE 2004 SUMATRA TSUNAMI, NOAA EXPANDED
THE D.A.R.T. PROGRAM FROM 6 TO 39 BUOY STATIONS IN
THE ATLANTIC AND PACIFIC OCEANS. ALTHOUGH THE SYSTEM HAS BEEN HAMPERED AT TIMES
BY MALFUNCTIONS, IT’S DESIGNED TO MEASURE
SIGNS OF TSUNAMI WAVES AND RELAY THE DATA TO WARNING
CENTERS IN HAWAII AND ALASKA. Evans: NOW,
A TSUNAMI WILL ACTUALLY TRAVEL AT HUNDREDS OF MILES PER HOUR. WHEN A WARNING IS ISSUED, OR IF YOU FEEL AN EARTHQUAKE
THAT KNOCKS YOU OFF YOUR FEET, YOU NEED TO GET AWAY
FROM THE COAST. YOU NEED TO GO INLAND
AND TO HIGHER GROUND. Narrator:
EVEN IF MAJOR TSUNAMIS OFF THE COAST OF CALIFORNIA
ARE RARE, THE DAMAGE THEY CAN CAUSE
REQUIRES CONSTANT VIGILANCE. Evans:
NATURE IS VERY POWERFUL, AND WE HAVE TO RESPECT IT. IF WE DON’T RESPECT IT, THAT’S
WHEN IT COMES AND GETS US.

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