[ MUSIC ]
>> HELLO AND WELCOME TO
"NASA SCIENCE LIVE".
TODAY, WE'RE DISCUSSING
IMPORTANT SCIENCE
AROUND EARTH'S ICY REGIONS
AND HOW IT CAN IMPACT
THOSE LIVING IN WARMER REGIONS
AROUND OUR PLANET.
YOU MIGHT HAVE HEARD IN THE NEWS
THAT ENOUGH ICE HAS MELTED
FROM ANTARCTICA
AND GREENLAND
TO RISE SEA LEVELS
ABOUT HALF AN INCH
OVER THE PAST 16 YEARS.
WE HAVE THE SCIENTISTS
BEHIND THAT NASA STUDY
TO TALK TO US MORE ABOUT
WHAT WE'VE LEARNED
AND WHAT IT MEANS
FOR OUR PLANET.
WE'LL ALSO TAKE YOU
TO THE COAST OF VIRGINIA
TO SEE THE REAL-WORLD IMPACTS
OF EARTH'S MELTING ICE.
BEFORE WE GET STARTED,
LET'S TAKE A STEP BACK
AND LEARN ABOUT
THE CRYOSPHERE.
THAT'S THE FROZEN WATER PARTS
ON EARTH'S SYSTEM.
>> HERE AT THE END OF THE EARTH
IT STILL FEELS LIKE A PLACE
FOR RAW EXPLORATION
AND ADVENTURE.
IT'S VAST IN ALL DIRECTIONS
AND GROUND ZERO FOR
SOME OF THE BIGGEST QUESTIONS
WE HAVE ABOUT THE CLIMATE.
BUT WHEN WE DECIDED TO
MAKE A SHOW ABOUT
THE FROZEN PLACES ON EARTH,
WE KNEW THERE WOULD BE
ONE HURDLE WE WOULD NEED TO
JUMP OVER FIRST.
>> UHH.
>> THE WHAT?
>> UMM.
>> OH.
>> I HAVE NO IDEA.
>> WHILE I'M AWARE OF
THE CRYOSPHERE,
I DON'T ACTUALLY KNOW
WHAT IT IS.
>> IT HAS SOMETHING TO DO
WITH ICE.
ALL RIGHT, THAT'S ALL I GOT.
[ MUSIC ]
>> HEY!
SO, HERE WE ARE
IN WASHINGTON, DC,
STANDING ON THE ROOF
OF NASA HEADQUARTERS.
THAT'S THE CAPITOL BUILDING
RIGHT BEHIND ME.
AND WHAT HEADQUARTERS DOES
IS KIND OF SERVE AS
THE FOCAL POINT
TO CONNECT THE DOTS.
THE CRYOSPHERE IS EVERYTHING
FROM THE SNOW THAT FALLS
BY YOUR HOUSE
TO THE ICY REACHES
OF THE HIMALAYAS
TO THE BIG, BIG, BIG ICE SHEETS
OF ANTARCTICA,
ALL THE WAY UP THE SOUTH POLE
AND ALSO THE FROZEN GROUND
OF THE ARCTIC
AND EVEN SOME OF
THAT FROZEN GROUND
THAT'S CURRENTLY
UNDER THE OCEAN.
>> IF YOU HAD TO BREAK IT DOWN,
YOU'D HAVE A MIX OF ...
>> RIGHT NOW,
OUR BEST PREDICTIONS
ARE THAT SEA LEVELS WILL RISE
ANYWHERE FROM ONE TO THREE FEET
WITHIN THE NEXT HUNDRED YEARS.
THREE FEET OF SEA LEVEL RISE
HAS THE POTENTIAL TO DISPLACE
ABOUT 100 MILLION PEOPLE,
WHICH IS A LOT OF PEOPLE
THAT NEED TO FIND NEW HOMES.
>> OUR CURRENT REALITY PLACES US
AT A NEAR TIPPING POINT
AND THE CRYOSPHERE
IS PLAYING A HUGE PART
IN THAT DELICATE BALANCE.
>> SO, ONE OF THE THINGS
PEOPLE DON'T KNOW ABOUT NASA
IS THAT WE STUDY THE EARTH.
AND WE'VE BEEN DOING THAT
SINCE NASA'S INCEPTION
BACK IN THE 1950'S.
AND WE STUDY
THE FROZEN PART OF THE EARTH
IN A VARIETY OF WAYS.
>> MISSIONS LIKE SNOWEX,
AIRBORNE SNOW OBSERVATORY,
OCEANS MELTING GREENLAND,
OPERATION ICEBRIDGE,
ARCTIC-BOREAL
VULNERABILITY EXPERIMENT
AND COUNTLESS OTHER LABS
AND INDIVIDUAL RESEARCHERS
STAND AT THE FOREFRONT
OF MONITORING THE CRYOSPHERE.
WE'RE TAKING YOU WITH US
AS WE FOLLOW NASA EXPLORERS
ON THEIR JOURNEY
TO THE FROZEN ENDS OF THE EARTH
AS THEY STUDY
OUR RAPIDLY CHANGING WORLD
FROM SATELLITES, PLANES
AND BOOTS ON THE GROUND.
>> WOW!
SO, IT SOUNDS LIKE
THE CRYOSPHERE IS PLACE
WE ALL DEPEND ON
BUT MANY OF US WILL NEVER GO TO.
I'M JOINED TODAY
BY ALEX GARDNER,
NASA GLACIOLOGIST.
ALEX, CAN YOU TELL US MORE ABOUT
WHY NASA STUDIES EARTH'S ICE?
>> YEAH, ABSOLUTELY.
NASA STUDIES EARTH'S ICE BECAUSE
IT'S INCREDIBLY IMPORTANT
FOR THE REST OF
THE EARTH'S SYSTEM.
THE POLES COVER A LARGE REGION
OF THE EARTH
AND THEY INTERACT WITH
THE EARTH'S SYSTEM IN WAYS
THAT CAUSE LARGE GLOBAL CHANGES.
THE MELTING OF THE ICE SHEETS
ARE RESPONSIBLE FOR
CHANGES IN SEA LEVEL RISE,
THE FORMATION OF SEA ICE DRIVES
THE THERMOHALINE CIRCULATION,
OR THE CIRCULATION
OF THE OCEAN.
YOU KNOW, CHANGES IN SNOW COVER
YEAR-TO-YEAR CAUSE
LARGE CHANGES
IN THE EARTH'S ENERGY BUDGET.
AND SO, IF WE WANT TO
UNDERSTAND THE EARTH,
WE NEED TO UNDERSTAND THE POLES.
>> SO, HOW DOES NASA
STUDY EARTH'S ICY REGIONS?
>> YEAH, GREAT QUESTION.
THERE'S A LOT OF DIFFERENT WAYS
THAT NASA STUDIES
THE POLAR REGIONS.
AND NASA IS REALLY WELL-EQUIPPED
TO DO THIS BECAUSE THESE ARE
VERY HARSH ENVIRONMENTS
THAT ARE DARK FOR
UP TO SIX MONTHS OF THE YEAR.
AND SO, NASA HAS A SUITE
OF SATELLITES
IN AIRBORNE MISSIONS
THAT ARE DESIGNED TO
STUDY THE POLAR REGIONS.
WE HAVE A SATELLITE
THAT LAUNCHED IN 2018, ICESAT-2,
THAT'S A VERY ADVANCED
LASER ALTIMETER THAT
COUNTS INDIVIDUAL PHOTONS
THAT BOUNCE OFF OF THE EARTH
TO MEASURE HEIGHT CHANGES.
WE HAVE ANOTHER SATELLITE
THAT LAUNCHED IN 2018,
THE GRACE FOLLOW-ON MISSION
AND THIS IS
A FASCINATING MISSION
THAT'S ABLE TO ACTUALLY MEASURE
SUBTLE CHANGES
IN THE EARTH'S GRAVITY.
SO, AS THE ICE SHEETS
GROW OR SHRINK,
WE CAN ACTUALLY SEE
GRAVITY CHANGE
IN RESPONSE TO THOSE CHANGES.
AND WE ALSO HAVE
THE AIRBORNE MISSION.
SO, WE HAVE A MISSION CALLED
THE OCEAN'S MELTING GREENLAND
THAT SURVEYS THE PERIPHERY
OF THE GREENLAND ICE SHEET
TO MEASURE CHANGES IN OCEANS
AND SEE HOW THAT'S IMPACTING
THE ICE SHEET.
>> WHAT ARE SOME OF
THE DISCOVERIES
THAT YOUR COLLEAGUES
HAVE BEEN MAKING
ABOUT THESE REGIONS?
>> YEAH.
SO, A FEW --
IT WASN'T VERY LONG AGO,
ONLY A FEW DECADES AGO,
WE ASSUMED THAT THE ICE SHEETS
WOULD RESPOND FAIRLY SLOWLY
TO CHANGES IN CLIMATE.
AND WHAT WE'VE DISCOVERED
OVER THE LAST FEW DECADES
IS THAT'S FAR FROM THE TRUTH.
THERE ARE ALL THESE REALLY
INTERESTING FEEDBACKS THAT OCCUR
THAT CAUSE THE ICE SHEETS
TO RESPOND MUCH MORE RAPIDLY
THAN WE HAD ANTICIPATED.
SO, THE OCEANS ARE ABLE TO
EAT AWAY AT THE EDGE
OF THE ICE SHEETS VERY QUICKLY,
WHICH CAUSES THE ICE
TO FLOW MORE RAPIDLY
INTO THE OCEAN.
WE'VE DISCOVERED
THAT WATER FROM THE SURFACE
CAN EASILY REACH THE BED
OF THE GLACIER,
RAISING THE PRESSURE
AT THE BED OF THE GLACIER
AND REDUCING THE FRICTION
THAT CAUSES IT TO --
THAT RESISTS THE FLOW
INTO THE OCEAN.
AND IN SOME PLACES
WE'VE DISCOVERED THAT
THE GEOMETRY OF THE BED
OF THE GLACIER
CAN CAUSE GLACIERS
TO RETREAT IRREVERSIBLY
ONCE THEY START TO RETREAT.
AND SO, THERE'S THESE LARGE
ONE-WAY FEEDBACKS IN SOME PLACES
THAT CAN CAUSE RAPID CHANGES
IN SEA LEVEL RISE.
>> IT IS SUCH
AN INTERESTING REGION.
WE'VE GOT SOME QUESTIONS
FROM SOCIAL MEDIA,
SO WE HAVE TWITTER,
"WHAT KIND OF INFORMATION,
CAN WE GET FROM ICE
AND HOW CAN THAT INFORMATION
BE USEFUL TO US?"
>> YEAH, SO THERE'S LOTS OF
DIFFERENT INFORMATION
WE CAN GET.
SOME OF THE MOST INTERESTING
INFORMATION IS ACTUALLY
COMING FROM ICE CORES
THAT GIVE US THESE LONG,
DETAILED RECORDS OF --
OF EARTH'S CLIMATE HISTORY
BECAUSE IT ACTUALLY TRAPS
LITTLE POCKETS OF AIR
IN THE ICE CORES.
NASA IS NOT COLLECTING
THE ICE CORES,
BUT WHAT WE ARE MEASURING IS
THE CHANGES IN THE ICE SHEETS.
AND SO WHAT WE CAN SEE IS
IF WE WARM THE TEMPERATURE
OF THE OCEAN
BY ONE OR TWO DEGREES,
WHAT DOES THAT MEAN FOR
HOW QUICKLY
THE ICE SHELVES MELT?
AND IF WE GENERATE WATER ON
THE SURFACE OF THE ICE SHEETS,
WHAT DOES THAT MEAN FOR
HOW FAST THAT
THEY CAN SLIDE INTO THE OCEAN?
AND SO, IT'S REALLY ABOUT
DEVELOPING UNDERSTANDING
SO THAT WE CAN PROVIDE
PROJECTIONS INTO THE FUTURE
OF WHAT THE RESPONSE
TO FUTURE CHANGES WILL BE.
>> WOW!
THAT'S FASCINATING!
SO, THANK YOU SO MUCH
FOR THIS INSIGHT, ALEX.
AS WE MENTIONED
AT THE BEGINNING OF THE SHOW,
NASA HAS JUST RELEASED
BRAND NEW SCIENCE RESULTS
ABOUT ACCELERATED ICE MELT.
LET'S TAKE A LOOK ABOUT
SOME OF THOSE DETAILS
ABOUT HOW EARTH'S ICE
IS CHANGING.
>> USING THE MOST ADVANCED
EARTH-OBSERVING LASER INSTRUMENT
NASA HAS EVER FLOWN IN SPACE,
SCIENTISTS HAVE MADE PRECISE
DETAILED MEASUREMENTS
OF HOW THE ELEVATION
OF ICE SHEETS IN GREENLAND
AND ANTARCTICA
HAVE CHANGED OVER 16 YEARS.
>> WE CAN ACTUALLY SEE
SOME PROCESSES AT A SCALE
THAT'S ALMOST LONG ENOUGH
TO TELL US ABOUT THE CLIMATE
IN THOSE TWO PLACES.
>> SCIENTISTS TOOK
ICE SHEET ELEVATION
MEASUREMENTS FROM 2003,
OVERLAID DATA FROM 2019
AND ANALYZED
WHERE THE DATASETS INTERSECTED
IN ORDER TO SEE
WHERE ICE WAS LOST OR GAINED.
FOR EXAMPLE,
THE STUDY DEFINITIVELY SHOWS
THAT THE EAST ANTARCTIC
ICE SHEET,
THE LARGEST
OF ALL THE ICE SHEETS,
IS GROWING.
>> BUT MORE IMPORTANTLY,
WHAT WE FIND IS THAT GROWING
IS MORE THAN OFFSET
BY INCREASED LOSSES COMING FROM
THE WEST ANTARCTIC ICE SHEET
WHICH IS THINNING VERY RAPIDLY
AS IT RESPONDS TO
WARMER OCEAN TEMPERATURES,
SPECIFICALLY IN THE AMANSON SEA
AND BAUMAN AREA.
>> THE WEST ANTARCTIC SIDE
WE ARE SEEING STRONG THINNING
ON THE ICE SHELVES
WHICH IS CAUSING DRAWDOWN
ON THE INLAND ICE,
ON THE GROUNDED ICE UPSTREAM.
MOST OF THAT IS BEING CAUSED
BECAUSE OF CHANGES
IN OCEAN HEAT FLUX
UNDERNEATH THE ICE SHELVES
WHICH IS CAUSING THEM TO THIN
AND THEN CONSEQUENTLY
THE BUTTRESSING FORCE
IS BEING LOST
AGAINST THE GROUNDED ICE
AND THE GROUNDED ICE
IS THEN FLOWING FASTER
INTO THE OCEAN
AND CAUSING SEA LEVEL RISE.
IN GREENLAND WE'RE SEEING
DIFFERENT SIGNATURES.
AGAIN, IN THE CENTER OF
THE ICE SHEET IN THE PLATEAU
WE'RE SEEING
INCREASED ACCUMULATION.
SO, THERE IS A SLIGHT INCREASE
IN MASS IN THE CENTER,
BUT THE OVERALL SIGNAL
FOR GREENLAND
IS ONE OF THINNING,
AND THAT IS BEING CAUSED BY
OCEAN AND ATMOSPHERIC SIGNALS
ACTING ALL AROUND
THE EDGES OF GREENLAND.
>> SO, WE'RE SEEING 200 GIGATONS
PER YEAR OF ICE
FLOWING INTO THE OCEANS,
WHICH IS ENOUGH
TO RAISE SEA LEVEL
BY ABOUT TWO-THIRDS
OF A MILLIMETER PER YEAR.
>> COMBINE THAT WITH
THE ALMOST 118-GIGATONS
LOST IN ANTARCTICA,
AND SEA LEVEL HAS RISEN
A TOTAL OF 14 MILLIMETERS
OVER THE 16-YEAR PERIOD
DUE TO ICE SHEET MELT.
IT MAY SEEM SMALL,
BUT THE SMALL CHANGES ADD UP.
>> WHAT WE EXPECT
BY THE END OF THE CENTURY IS,
YOU KNOW, ON THE ORDER OF TWO,
THREE, MAYBE FOUR FEET
OF SEA LEVEL RISE.
AND BECAUSE WE HAVE
ALL OF OUR INFRASTRUCTURE
THAT IS BUILT AROUND THE COASTS,
WE HAVE A LOT OF VULNERABILITY
TO A METER CHANGE
IN SEA LEVEL RISE.
>> THE POTENTIAL IMPACT
FROM SEA LEVEL RISE
IS ONE CRITICAL MOTIVATION
FOR THE CONTINUED STUDY
OF THE MECHANICS
DRIVING THE CHANGES
IN THE ICE SHEETS.
>> IF WE CAN UNDERSTAND
THOSE MECHANISMS
AND HOW THEY'VE PLAYED OUT
OVER THE LAST 30 YEARS,
WELL THEN WE CAN START TO LOOK
AND THINK ABOUT
HOW WILL THOSE ICE SHEETS
RESPOND TO
WHAT WE PROJECT THE CLIMATE
TO BE INTO THE FUTURE.
>> THAT IS JUST INCREDIBLE.
IT SOUNDS LIKE WITH THESE TOOLS,
SCIENTISTS ARE ABLE TO
BE MORE CONFIDENT THAT
THE CHANGES WE'RE SEEING
IN THE ICE
HAVE TO DO WITH
THE LONG-TERM CHANGES
IN THE CLIMATE.
LET'S LEARN SOME MORE
ABOUT THAT SCIENCE.
I'M JOINED BY BEN SMITH,
LEAD AUTHOR
OF THE ICESAT-2 STUDY.
BEN, CAN YOU TAKE US THROUGH
THESE RESULTS WE JUST LEARNED?
>> SO, WE ARE MAKING
OUR FIRST SET OF MEASUREMENTS
WITH ICESAT-2.
AND WHAT'S EXCITING ABOUT THESE
IS THAT THEY CONTINUE
A SET OF MEASUREMENTS
THAT WERE FIRST TAKEN
IN MOSTLY THE EARLY 2000'S.
SO, THOSE MEASUREMENTS ARE --
WERE DONE WITH ICESAT-1.
THEY WERE
LASER ALTIMETRY MEASUREMENTS
OF BOTH ICE SHEETS AND THEY --
THE DIFFERENCES
BETWEEN THOSE TWO LET US SEE
HOW THE ICE IS CHANGING
OVER THE 16-YEAR PERIOD
BETWEEN THE START OF
THE ICESAT-1 MISSION
AND THE BEGINNING
OF THE ICESAT-2 MISSION.
SO, WITH THOSE MEASUREMENTS
WE CAN SEE A LOT OF
SORT OF EXCITING THINGS.
WE CAN SEE AROUND THE EDGES
OF GREENLAND
AND THE EDGES
OF PARTS OF ANTARCTICA
THAT THE ICE IS THINNING
VERY QUICKLY.
THERE ARE AREAS
WHERE THE ICE SHEET SURFACE
IS DROPPING BY
MORE THAN SEVERAL METERS
PER YEAR.
SO, TENS OF FEET PER YEAR.
AS YOU GO FARTHER INLAND
FROM THERE,
YOU SEE LESS AND LESS THINNING,
IN GENERAL,
UNTIL IN THE VERY INTERIOR
OF THE ICE SHEETS
WE ACTUALLY SEE
SMALL AMOUNTS OF THICKENING.
SO, WHAT THIS MEANS TO US
IS THAT THERE ARE
RAPID THINNING PROCESSES
THAT ARE HAPPENING
IN ASSOCIATION WITH CHANGES
THAT ARE HAPPENING IN THE OCEAN
AND THE CLIMATE.
AND THOSE ARE AFFECTING
THE LOW ELEVATION PARTS
OF THE ICE SHEET
THAT ARE CLOSEST TO THE OCEAN.
FARTHER INLAND,
THERE'S MORE SNOW FALLING
THAN CAN BE TAKEN AWAY
BY ICE FLOW.
AND SO, THE ICE SHEET
IS THICKENING A LITTLE BIT.
THE MISSION ALSO LET'S US
ADD UP THOSE DIFFERENCES.
SO, WE CAN ADD UP
HOW MUCH THICKENING WE SEE
AND HOW MUCH THINNING WE SEE.
AND WE FIND THAT THE THICKENING,
IT IS, AT THIS POINT,
VERY, VERY SMALL
COMPARED TO
THE THINNING THAT WE SEE.
SO, THE RAPID THINNING
THAT WE SEE AROUND THE COAST
DOMINATES THE THICKENING
THAT WE SEE IN THE INTERIOR.
AND SO, BOTH ICE SHEETS
ARE LOSING
QUITE A BIT OF MASS.
>> AND WHY ARE THESE RESULTS
SO SIGNIFICANT?
>> SO, THIS IS KIND OF
A DEFINITIVE STUDY.
SO, WE'RE MAKING
LASER ALTIMETRY MEASUREMENTS.
WE KNOW THAT THESE MEASUREMENTS
ARE MEASURING EXACTLY
THE SURFACE OF THE SNOW.
WE HAVE VERY HIGH PRECISION
SO WE CAN MEASURE
AT THE SORT OF INCH LEVEL
HOW MUCH THE ICE SHEET
HAS CHANGED.
AND WE HAVE A LONG TIME PERIOD,
SO WE HAVE
A 16-YEAR TIME PERIOD,
SO IT'S NOT JUST THAT
WE HAD A SNOWY YEAR ONE YEAR
OR WE JUST HAD A LITTLE BIT
OF EXTRA MELT ONE YEAR,
WE'RE SEEING PROCESSES
THAT HAVE BEEN GOING ON
CONSISTENTLY FOR A LONG TIME
AND WE CAN SEE
THE EFFECT OF THAT
ADDED UP OVER A NUMBER OF YEARS.
>> AND WHY IS THE ICE MELTING?
>> SO, WE'RE SEEING
TWO DIFFERENT EFFECTS HERE
IN COMBINATION WITH
ONE ANOTHER.
WE MEASURE THE NET EFFECT
OF THESE TWO THINGS.
WE'RE SEEING
AROUND THE EDGE OF ANTARCTICA
AND THE EDGE OF GREENLAND
THAT THE OCEAN IS WARMER
AND THAT'S MELTING ICE DIRECTLY.
SO, THE ICE SHELVES
AROUND ANTARCTICA,
WHICH ARE FLOATING ICE,
ARE THINNING QUITE A BIT.
AND THE ICE
AT THE DOWNSTREAM ENDS OF
THE OUTLYING GLACIERS
IN GREENLAND
ARE MELTING QUITE A BIT.
THAT LETS THE ICE FLOW FASTER
BECAUSE THERE'S LESS RESISTANCE
TO ITS FLOW.
AND SO, AS THE ICE
FLOWS FASTER,
THE GLACIERS GO FASTER
AND ICE CAN FLOW
FROM THE ICE SHEETS
INTO THE OCEAN MORE QUICKLY.
SO, AT THE SAME TIME,
IN GREENLAND
WE'RE ALSO SEEING THE EFFECTS
OF SURFACE MELT.
SO, THE WEATHER
HAS GOTTEN WARMER IN GREENLAND
BY QUITE A BIT
AND A LOT LARGER PART
OF THE ICE SHEET IS MELTING.
AND IT'S MELTING MORE
EVERY SUMMER.
SO, WE'RE SEEING MELT --
SURFACE MELT
AND FASTER ICE FLOW IN GREENLAND
AND WE'RE SEEING FASTER ICE FLOW
AND ICE SHELF MELT
IN ANTARCTICA.
>> THANK YOU.
SO, I THINK WE HAVE TIME FOR
ONE QUESTION
FROM SOCIAL MEDIA.
OUR QUESTION FROM TUMBLR IS
"HOW DO YOU GUYS HELP
WITH CLIMATE CHANGE?"
>> SO, WE ARE OBSERVING
THE EFFECTS OF CLIMATE CHANGE.
WE ARE PRESENTING THE FACT
THAT WE'RE SEEING THESE CHANGES
AND WE ARE SHOWING THAT
THEY ARE PRETTY SIGNIFICANT.
WHAT ACTUALLY HELPS IS
WHAT PEOPLE DO
IN RESPONSE TO THIS.
SO, WHEN PEOPLE SEE THAT
WE'VE PRODUCED
ABOUT 14-MILLIMETERS
OF SEA LEVEL RISE
BETWEEN THESE TWO MISSIONS,
WE MIGHT THINK ABOUT
WHAT WE NEED TO DO
IN RESPONSE TO THAT.
>> WELL, THANK YOU SO MUCH
FOR JOINING US TODAY, BEN,
AND WALKING US THROUGH
THESE AMAZING SCIENCE RESULTS
ON EARTH'S ICE.
FOR THOSE OF YOU
JUST JOINING US,
WE'RE LEARNING ABOUT
JUST RELEASED FINDINGS
ABOUT EARTH'S ICE.
ONE OF THE THINGS
WE'VE HEARD OUR EXPERTS MENTION
A FEW TIMES IS SEA LEVEL RISE.
I'M JOINED BY DR. HELEN FRICKER,
GLACIOLOGIST,
WHO IS GOING TO GIVE US
A BETTER IDEA
OF HOW SEA LEVEL RISE WORKS.
HELEN, THANK YOU FOR JOINING US.
>> YOU'RE WELCOME.
THANK YOU FOR HAVING ME.
>> SO, I UNDERSTAND
IT'S NOT JUST
WARMER AIR TEMPERATURES
THAT ARE MELTING ICE,
BUT WARMER OCEAN TEMPERATURES
AS WELL.
HOW DOES THE OCEAN
HAVE AN IMPACT ON ANTARCTIC ICE?
>> THAT'S RIGHT.
SO, ALL AROUND
THE EDGES OF ANTARCTICA
THERE ARE PARTS OF THE ICE SHEET
THAT REACH THE OCEAN.
AND IN THESE PLACES,
WE HAVE VERY LARGE AREAS
OF THICK ICE
THAT'S FLOATING ON TOP OF
THE OCEAN.
WE CALL THESE ICE SHELVES.
NOW SOME OF THESE ICE SHELVES
ARE SO BIG
THAT THEY'RE THE SIZE OF TEXAS
OR FRANCE.
SOME OF THEM ARE MUCH SMALLER.
BUT WHAT THEY DO IS
THEY HOLD BACK THE ICE,
THE GROUNDED ICE ON --
SITTING ON THE MAIN PART
OF THE CONTINENT.
AND SO, IT'S KIND OF LIKE
A BUFFER REGION
WHERE IF THIS ICE SHELF
WASN'T THERE,
THE ICE WOULD FLOW MUCH FASTER
INTO THE OCEAN.
YOU COULD THINK OF THEM
LIKE A BUTTRESS,
AN ARCHITECTURAL BUTTRESS
SITTING THERE
HOLDING THE GROUNDED ICE
BACK ONTO THE ICE SHEET.
>> SO, WHEN ICE THAT IS
ALREADY FLOATING MELTS,
HOW DOES THAT RAISE SEA LEVELS?
>> RIGHT.
SO, THE ICE THAT'S FLOATING
THE ICE SHELVES,
WHEN IT MELTS
IT DOESN'T RAISE SEA LEVEL
STRAIGHTAWAY BECAUSE
THAT ICE IS ALREADY FLOATING.
YOU CAN THINK OF IT
A BIT LIKE YOUR GLASS OF WATER.
I HAVE A DEMONSTRATION HERE.
THIS IS A GLASS WHICH HAPPENS
TO HAVE ANTARCTICA ON IT.
IF I PUT ICE CUBES IN THE GLASS,
IF YOU WATCH
THE LEVEL OF THE WATER,
IT WILL GO UP.
THIS IS BECAUSE
I'M ADDING MORE ICE TO MY GLASS.
AND SO, THE LEVEL
HAS GONE UP ABOVE,
SO NOW YOU CAN'T SEE
ANTARCTICA ANYMORE.
BUT IF THIS ICE MELTS,
THEN THE LEVEL OF THE LIQUID
IN THE GLASS STAYS THE SAME.
AND THIS IS LIKE AN ICE SHELF.
WHEN AN ICE SHELF MELTS,
THE LEVEL STAYS THE SAME;
HOWEVER, WHAT IT'S DOING IS
IT'S REDUCING
THIS BUTTRESSING FORCE
THAT I JUST TALKED ABOUT
THAT THE ICE SHELVES PLAY
IN THE ICE SHEET.
AND IF YOU REDUCE THAT
BUTTRESSING FORCE AND MAKE --
IF THE ICE SHELF
BECOMES THINNER,
ITS BUTTRESSING FORCE IS LESS
AND THE GROUNDED ICE BEHIND IT
WILL BE ADDED TO THE OCEAN.
AND THAT'S JUST LIKE THE ICE
THAT I ADDED TO THE GLASS.
>> THAT'S A GREAT
DEMONSTRATION.
SO, WHAT IS THAT MADE YOU
WANT TO STUDY ICE?
>> I WANTED TO STUDY ICE
AND, IN PARTICULAR ANTARCTICA,
WHEN I STARTED MY PH.D.
I JUST FOUND IT SO FASCINATING
TO THINK ABOUT THIS.
FIRST OF ALL,
THIS CONTINENT
AT THE BOTTOM OF THE EARTH
THAT'S SO FAR AWAY
FROM EVERYWHERE ELSE
BUT IT'S SO IMPORTANT TO US ALL.
THIS INTERCONNECTION OF
THE ENTIRE EARTH SYSTEM
WITH THESE DIFFERENT FORCINGS,
THE ATMOSPHERE, THE OCEAN
AND JUST ALSO THE THRILL
OF ANTARCTIC EXPLORATION.
AND THEN LATER IN MY CAREER,
I'VE ALSO GOT INTERESTED
IN GREENLAND.
THE ICE SHEET
IN THE NORTHERN HEMISPHERE,
VERY SIMILAR PROCESSES
ACTING THERE,
BUT IN DIFFERENT-
DIFFERENT AMOUNTS.
SO TOGETHER,
ALL OF THE ICE SHEETS
ARE JUST SO FASCINATING TO ME.
I MEAN, I THINK WE SIT HERE IN,
WELL, AT HOME AT THE MOMENT,
BUT IN OUR, YOU KNOW,
INHABITED PLACES THAT WE LIVE
AND WE DON'T REALLY THINK
THAT THESE CONTINENTS
THAT ARE SO FAR AWAY
ARE GOING TO AFFECT US.
BUT ACTUALLY, THEY DO
BECAUSE SEA LEVEL
IS GOING TO AFFECT MANY,
MANY PEOPLE
ALL AROUND THE WORLD.
>> YEAH.
THANK YOU SO MUCH FOR
EXPLAINING THAT TO US, HELEN.
I KNOW IT REALLY HELPED ME
GRASP THE CONCEPT OF
HOW SEA LEVEL RISE WORKS
AND HOW ALL OF THESE THINGS
ARE INTERCONNECTED.
THANK YOU SO MUCH
FOR JOINING US.
>> OH, YOU'RE WELCOME.
>> SO, ANOTHER WAY TO UNDERSTAND
SEA LEVEL RISE
IS TO GO INTO
SOME OF THE COMMUNITIES
THAT ARE BEING IMPACTED
BY RISING WATERS.
RECENTLY, OUR TEAM VISITED
THE CITY OF NORFOLK
AND THE VIRGINIA INSTITUTE
OF MARINE SCIENCE TO SEE
HOW THE HAMPTON ROADS REGION
IS RESPONDING TO SEA LEVEL RISE
AND THE EFFECTS
OF CLIMATE CHANGE.
LET'S TAKE A LOOK.
>> SEA LEVEL RISE IS
A MEASUREABLE DIFFERENCE
IN WATER LEVEL OVER TIME.
AND DIRECTLY CONTRIBUTING
TO THAT IS, OF COURSE,
CLIMATE CHANGE.
SO, AS THE TEMPERATURES RISE,
POLAR ICECAPS MELT AND
SLOWLY THE WATER LEVEL RISES
THROUGHOUT THE GLOBE.
AND THERE ARE LOCALIZED IMPACTS
OF SEA LEVEL RISE.
>> IN HAMPTON ROADS
WE ARE PARTICULARLY VULNERABLE
TO COASTAL FLOODING.
>> THE HAMPTON ROADS REGION
OF VIRGINIA IS THE SECOND MOST
HEAVILY-IMPACTED REGION
IN THE UNITED STATES
WHEN WE TALK ABOUT
SEA LEVEL RISE AFTER,
OF COURSE, NEW ORLEANS.
>> WE'RE STANDING HERE
AT THE HAGUE,
PART OF NORFOLK, VIRGINIA,
WHICH IS IN THE MOUTH
OF THE CHESAPEAKE BAY
IN SOUTHEAST VIRGINIA.
THIS AREA WILL SEE
WHAT WE CALL BLUE SKY FLOODING
QUITE REGULARLY
WHERE THERE'S NO STORM EVENT.
AND SO, THIS WATER COMES UP
OVER ONTO THIS SIDE,
WATER BREACHES THE BULKHEAD,
FLOODS THE AREA AROUND IT
AND THE ROAD BEHIND ME, AS WELL.
>> A LOT OF MY RESEARCH
AT THE VIRGINIA INSTITUTE
OF MARINE SCIENCE
INVOLVES THE DEVELOPMENT
OF PHYSICS-BASED
HYDRODYNAMIC MODELS.
THESE MODELS TELL US
WHERE FLOODING
IS GOING TO HAPPEN
BEFORE IT DOES,
WHEN, AND FOR HOW LONG.
BUT YOU'LL SEE ALL OF THESE
INDIVIDUAL STRUCTURES HERE,
MOST OF THEM NEAR THE WATERFRONT
ARE INUNDATED.
INFORMATION PROVIDED BY
NASA SATELLITES
MOSTLY ALLOWS US
TO VALIDATE THE ACCURACY
OF OUR MODEL
IN TERMS OF TELLING US
WHERE THE FLOODING
ACTUALLY HAPPENED FROM SPACE.
>> THE MAPS THAT COME OUT
OF THE MODELS ARE REALLY USEFUL
AT SHOWING THE DEPTH OF WATER
THROUGHOUT THE CITY
AT THE STREET LEVEL
SO THAT WE CAN, YOU KNOW,
JUST MAKE BETTER
DATA-DRIVEN DECISIONS
AROUND THE CITY.
>> THESE ARE TWO STANDARD
ACTIVE REMOTE SENSORS.
>> THIS IS AN EXAMPLE OF
A PRESSURE TRANSDUCER
WATER SENSOR.
AND WHAT WE'VE BEEN TRYING TO DO
IS COMPARE DATA
LIKE NASA SATELLITE IMAGERY
TO SEE HOW IT COMPARES TO
THE ACCURACY
THAT WE'RE GETTING
AT THE STREET LEVEL.
SO, WHEN YOU
PUT IT ALL TOGETHER,
IT'S VERY VALUABLE.
>> ONE OF THE MAIN APPLICATIONS,
LIKE IT'S REALLY TRYING TO SEE,
BEFORE THESE EVENTS HAPPEN,
WHERE IS GOING TO BE
THE PROBLEM AREAS
IN OUR COMMUNITIES.
>> DETERMINE WHAT ROADS
NEED TO BE CLOSED
OR INTERSECTIONS
NEED TO BE CLOSED WHEN.
>> WHERE THESE PROJECTS
SHOULD BE PERMITTED.
WILL THIS BUILDING LAST
THE 30-YEAR LIFE
OF THE STANDARD MORTGAGE?
OUR MODELS, AS A REPRESENTATION
OF REALITY,
HAVE TO BE AS ACCURATE
AS POSSIBLE.
THE ADDITIONAL INFORMATION
FROM THE NASA SATELLITES
LANDSAT, NISTAR AND [INDISTINCT]
REALLY HELPS US
CALIBRATE OUR MODEL.
>> HAVING THAT REGIONAL
WATER-DEPTH MAP
REALLY HELPS US
HAVE AN UNDERSTANDING
WHAT THE FUTURE DAY-TO-DAY
LOOKS LIKE IN NORFOLK
WITH SEA LEVEL RISE.
>> AND SO,
A BETTER UNDERSTANDING
OF SEA LEVEL RISE
WILL HELP YOU DECIDE THE PLACES
WHERE YOU MAY WISH TO WORK
OR LIVE IN THE NEAR FUTURE.
IT ALSO HELPS
TO BETTER UNDERSTAND
SPECIFICALLY WHAT YOUR RISK IS
INHERIT NOT JUST WITH FLOODING,
BUT ALSO WITH THE CHANGES
TO OUR CLIMATE AS
OUR WORLD CONTINUES TO CHANGE,
EITHER FOR THE BETTER
OR WORSE.
>> THAT WAS AN INFORMATIVE
LOOK AT HOW COMMUNITIES
IN THE HAMPTON ROADS REGION
ARE DEALING WITH
THE IMPACT OF SEA LEVELS RISING
ALONG THEIR COAST.
THANK YOU TO
THE CITY OF NORFOLK
AND THE VIRGINIA INSTITUTE
OF MARINE SCIENCE
FOR SHOWING US
HOW THEY USE NASA DATA
IN THESE SITUATIONS.
SPEAKING OF NASA DATA,
WE'VE TALKED A LOT ABOUT
HOW THE NEW INFORMATION
GATHERED FROM ICESAT-2
WILL HELP US.
I BET YOU DIDN'T KNOW THAT
IN ADDITION TO
THE DATA GATHERED FROM SPACE,
WE HAVE RESEARCHERS
TRAVELING INTO THE FIELD
TO CONDUCT GROUND OBSERVATIONS
THAT VALIDATE WHAT WE'RE SEEING
FROM THE VANTAGE OF SPACE.
LET'S TAKE A LOOK AT
THE FOOTAGE TAKEN
FROM SOME OF
THOSE FIELD CAMPAIGNS TO
GET A SENSE OF WHAT IT'S LIKE.
>> HI, THERE.
I'M [INDISTINCT] FROM NASA
AND WE ARE ON PENNY BAY
DOING ICESAT-2 VALIDATION WORK
ON SEA ICE
I'M MEASURING SEA ICE THICKNESS
WITH AN EM31.
>> AND I'M MEASURING SNOW DEPTH
WITH A MAGNAPROBE.
>> WHAT YA DOIN', KELLY?
>> TRYING TO BREATHE?
WHAT'S THE PROBLEM
WITH YOUR BREATHING?
>> SO, IT'S REALLY COOL
TO BE RIGHT NEXT TO ONE.
YOU CAN SEE ALL THE STRUCTURE
IN THE GLACIER.
YOU KNOW, THESE GLACIERS FORM
AS SNOW FROM YEAR AFTER YEAR
PACKS ON TOP AND
COMPRESSES DOWN INTO ICE.
AND SO, THEY PROVIDE
A HISTORY OF THE CLIMATE
AS WELL AS BEING
REALLY BEAUTIFUL.
>> WOW!
WHAT AN INCREDIBLE PERSPECTIVE
TO SEE HOW RESEARCHERS WORK
IN THESE EXTREME ENVIRONMENTS.
IT'S REALLY AMAZING.
TO TELL US MORE ABOUT
SOME OF OUR OWN EXPERIENCES
WORKING IN ANTARCTICA,
I'M JOINED BY BROOKE MEDLEY.
THANK YOU FOR BEING HERE TODAY.
>> THANK YOU FOR HAVING ME ON.
>> SO, BROOKE,
YOU'RE THE DEPUTY
PROJECT SCIENTIST
FOR OPERATION ICEBRIDGE.
COULD YOU EXPLAIN WHERE AND WHY
YOU GO INTO THE FIELD
TO STUDY ICE?
WHY DID YOU GO INTO THE FIELD
WHEN WE CAN JUST FLY OVER IT?
>> THAT'S A REALLY GREAT
QUESTION.
SO, I'VE HAD
THE FORTUNATE OPPORTUNITY
TO BE ABLE TO GO TO
BOTH GREENLAND TWICE LAST YEAR
AND ANTARCTICA, AS WELL,
MOST RECENTLY ANTARCTICA.
I JUST GOT BACK A FEW MONTHS AGO
FROM ANTARCTICA
WHERE WE ACTUALLY WERE
ON THE GROUND, ON THE ICE
TAKING MEASUREMENTS
BOTH OF SURFACE ELEVATION,
WHICH IS WHAT WE SEE
WITH ICESAT-2,
BUT ALSO OTHER SORT
OF MEASUREMENTS
OF HOW MUCH SNOW THERE WAS
ON THE GROUND,
HOW THICK IS THE ICE,
DIFFERENT SORT OF MEASUREMENTS
THAT HELP US BETTER INTERPRET
WHAT WE CAN SEE
FROM SATELLITE --
FROM ONLY
JUST THE SATELLITE DATA.
BUT WHILE WE WERE IN THE FIELD
IN ANTARCTICA,
WE HAD THE UNIQUE OPPORTUNITY
OF ALSO BEING
IN THE SAME LOCATION
AS OPERATION ICEBRIDGE,
WHICH IS AN AIRBORNE
NASA MISSION.
AND SO, OPERATION ICEBRIDGE
ACTUALLY IS A MORE THAN
TEN-YEAR-LONG MISSION
THAT WAS TASKED TO ACTUALLY
BRIDGE THE GAP BETWEEN ICESAT,
OUR ORIGINAL LASER
ALTIMETER MISSION, AND ICESAT-2.
IT'S THIS REALLY AMAZING CHANCE
TO HAVE THE HIGH SATELLITE
IN THE SKY MEASURING THE EARTH,
THEN WE HAVE
OUR AIRBORNE CAMPAIGN
THAT HAS LOTS OF
DIFFERENT INSTRUMENTS
INCLUDING ONE THAT IS THE SAME,
EFFECTIVELY,
AS WHAT ICESAT-2 HAS ONBOARD.
AND THEN WE'RE ON THE GROUND.
SO, WHAT THAT DOES IS
IT REALLY GIVES US
THE BEST PICTURE
OF HOW THE ICE IS CHANGING
AND WE CAN THEN HAVE THE --
HAVE THE MOST CONFIDENCE
IN OUR MEASUREMENTS
BECAUSE WE SEE IT
AT EVERY SINGLE LEVEL.
>> SO, WHEN YOU'RE
OUT IN THE FIELD,
WHAT DOES A NORMAL DAY
LOOK LIKE FOR YOU?
>> SO, WHEN YOU'RE --
SAY IF YOU'RE ON
OPERATION ICEBRIDGE,
WHICH IS THE AIRBORNE CAMPAIGN,
IT'S-IT'S, UM--
WE BASE TYPICALLY
NOT ON THE ICE SHEET
FOR ANTARCTICA.
SO, WE'LL BE BASED OUT OF
SOUTH AMERICA OR AUSTRALIA,
AND WE DO VERY LONG FLIGHTS.
SO, IMAGINE YOU'RE ON A PLANE
FOR 12 HOURS A DAY,
FIVE DAYS A WEEK.
SO, IT CAN BE VERY GRUELING
AND VERY DIFFICULT,
BUT YOU GET TO SEE
SOME OF THE MOST FANTASTIC
SCENERY I'VE EVER
BEEN ABLE TO SEE.
WHEN YOU'RE ON THE GROUND,
IT'S MUCH DIFFERENT.
SO, YOU'RE ACTUALLY IN THE COLD
TRYING TO COLLECT MEASUREMENTS
AND DOING THE BEST THAT YOU CAN,
EVEN THOUGH YOU'RE IN HUGE GEAR,
IT'S WINDY
AND YOU JUST WANT TO
KIND OF CRAWL BACK INSIDE
AND GET WARM AGAIN.
SO, A LITTLE BIT
DIFFERENT, UM, PERSPECTIVES,
BUT AT THE END OF THE DAY,
WE'RE TRYING TO ANSWER
THE SAME SCIENCE QUESTIONS,
WHICH IS, UM --
AND COMPLEMENT ONE ANOTHER,
AS WELL.
>> THAT SOUNDS INCREDIBLE.
WHAT IS IT THAT MADE YOU
DECIDE TO STUDY ICE?
>> THAT'S A GREAT QUESTION.
SO, I NEVER EVEN REALLY KNEW
WHAT A GLACIER WAS
PROBABLY UNTIL I WAS IN COLLEGE.
AND I'D NEVER SEEN ONE,
YOU KNOW, WITH MY OWN EYES.
AND SO, I HAD THE OPPORTUNITY
TO MOVE TO OREGON
AFTER UNDERGRADUATE,
AND WHEN I DID,
I SAW MY FIRST GLACIER AND I --
I HATE TO SOUND CLICHÉ,
BUT I ABSOLUTELY FELL IN LOVE.
AND SO, AFTER THAT,
I COMPLETELY CHANGED
MY CAREER PATH
TO FOCUS ON RESEARCH,
AND SPECIFICALLY RESEARCH
REGARDING GLACIERS
AND ICE SHEETS.
AND I COULDN'T BE HAPPIER, SO--
>> WOW!
WHAT AN EXPERIENCE.
THANK YOU SO MUCH
FOR JOINING US TODAY
AND TAKING US INTO
THE FIELD WITH YOU.
>> ABSOLUTELY.
IT WAS MY PLEASURE.
>> AND THANK YOU
FOR EVERYONE WATCHING AT HOME
AS WE EXPLORED
EARTH'S ICY REGIONS.
AND EXAMINE SOME OF
THE LATEST SCIENCE ABOUT
HOW OUR PLANET IS CHANGING.
YOU CAN CONTINUE
LEARNING ABOUT EARTH
AND THE WAYS NASA STUDIES IT
BY VISITING NASA.GOV/EARTH
OR FOLLOWING @NASA_ICE
ON FACEBOOK AND TWITTER.
SEE YOU NEXT TIME.
