>>> PRESENTATION OF SCIENCE TREK
ON IDAHO PUBLIC TELEVISION IS
MADE POSSIBLE THROUGH THE
GENEROUS SUPPORT OF THE LAURA
MOORE CUNNINGHAM FOUNDATION,
COMMITTED TO FULFILLING THE
MOORE FAMILY LEGACY OF BUILDING
THE GREAT STATE OF IDAHO.
>>> THE EARTH IS OUR HOME, BUT
IT'S MADE UP OF MANY COMPLEX
SYSTEMS WORKING TOGETHER TO KEEP
US ALIVE.
FIND OUT MORE ABOUT THE EARTH.
STAY TUNED.
SCIENCE TREK IS NEXT.
>>> HI, I'M JOAN CARTAN-HANSEN,
AND WELCOME TO SCIENCE TREK, AND
WELCOME TO BOISE STATE
UNIVERSITY'S EARTH, SCIENCE,
RESEARCH LAB.
WE'RE HERE TO ANSWER YOUR
QUESTIONS ABOUT THE EARTH, BUT
BEFORE WE DO, LET'S LEARN A BIT
MORE.
>> LET'S SEE IF WE CAN KEEP IT
UP IN THE AIR, AND WHO FOR THE
LONGEST.
>> OK.
>> DID YOU KNOW THE EARTH IS
93 MILLION MILES FROM THE SUN?
THE EARTH IS THE THIRD PLANET
FROM THE SUN.
THE EARTH'S ORBIT IS MORE LIKE
AN ELLIPSE RATHER THAN A PERFECT
CIRCLE.
THE EARTH SPINS ON AN AXIS, AND
AN IMAGINARY LINE THAT GOES FROM
POLE TO POLE.
THE EARTH IS AT A TILT, IT'S THE
TILT THAT GIVES US OUR SEASONS
AS THE EARTH TRAVELS AROUND THE
SUN.
WHEN THE NORTHERN HEMISPHERE
TILTS AWAY FROM THE SUN, YOU
HAVE WINTER.
AND AS THE NORTHERN HEMISPHERE
TILTS TOWARDS THE SUN, WE GET
SUMMER.
AND BECAUSE THE EARTH IS
SPINNING ON ITS AXIS, ONE SIDE
OF THE PLANET FACES THE SUN AND
THE OTHER IS IN THE SHAD OV,
THAT'S WHAT GIVES US DAY AND
NIGHT.
>> DID YOU KNOW THAT OXYGEN ONLY
MAKES UP 20% OF OUR AIR?
>> THE EARTH IS COVERED BY A
BLANKET OF GASES KNOWN AS THE
SPHERE.
THE TROPOSPHERE IS THE LOWEST
LEVEL, THAT'S WHERE YOU WILL
FIND THE AIR WE BREATHE.
THE AIR IS 20% OXYGEN AND 70%
NITROGEN, AND THE REST IS MADE
UP OF OTHER GASES.
ALL OF THE EARTH'S WEATHER
HAPPENS IN THE TROPOSPHERE.
THE NEXT LAYER IS THE
STRATOSPHERE.
THIS LAYER CONTAINS OZONE, A GAS
THAT PROTECTS US FROM THE
HARMFUL ULTRAVIOLET RAYS OF THE
SUN.
AFTER THAT, IS THE MESOSPHERE.
THIS IS THE LAYER WHERE
METEORITES USUALLY BURN UP FROM
SPACE CREATING SHOOTING STARS.
THEN THERE IS THE THERMO SPHERE,
AND FINALLY THE EXOSPHERE.
THIS IS THE OUTO MOST LAYER AT
THE EDGE OF SPACE.
>> LET ME PLAY!
>> NO WAY.
>> SO, DID YOU KNOW THAT THE
EARTH'S CRUST IS ALWAYS MOVING?
>> THE EARTH HAS FOUR MAIN
LAYERS.
AT THE CENTER IS AN EXTREMELY
HOT CORE.
THE CORE IS MADE UP OF TWO
REGIONS.
THE INNER CORE IS MADE UP OF
SOLID, IRON, AND NICKEL.
THE OUTER CORE IS MADE UP OF
LIQUID IRON.
THEY THINK THAT THE CIRCULATION
OF THAT LIQUID CAUSES THE
MAGNETIC FIELD AROUND THE EARTH.
THE NEXT LAYER IS THE MANTLE,
AND THEN THE OUTER LAYER, THE
LAYER WE LIVE ON, IS KNOWN AS
THE CRUST.
THE CRUST IS ABOUT FOUR TO
40 MILES THICK AND MAKES UP LESS
THAN 1% OF THE EARTH'S MASS.
IT'S BROKEN UP INTO PIECES KNOWN
AS TECTONIC PLATES.
TECTONIC PLATES ARE PUSHED AND
PULLED AROUND BY THE SLOW AND
STEADY MOVEMENT OF THE
UNDERLYING ROCK.
AS THE PLATES MOVE, STRESSES
BUILD UP.
EARTHQUAKES HAPPEN WHEN THE
STRESSES GROW BIG ENOUGH THAT
THE PLATES SLIDE PAST ONE
ANOTHER QUICKLY, AND WE FEEL
THAT SHAKING.
MOST VOLCANOS APPEAR ALONG PLATE
BOUNDARIES.
LOTS OF THINGS CAN CHANGE THE
EARTH'S SURFACE.
SOME HAPPENS QUICKLY FROM STRONG
THINGS LIKE EARTHQUAKES AND
VOLCANOES.
OTHERS HAPPEN OVER PERIODS OF
TIME BECAUSE OF PROCESSES LIKE
EROSION FROM WIND OR WATER.
YOU CAN SEE PATTERNS IN ROCK
FORMATIONS AND FOSSILS IN ROCK
LAYERS THAT SHOW CHANGES IN THE
EARTH'S SURFACE OVER TIME.
HUMANS CHANGE THE LOOK OF
EARTH'S SURFACE, TOO.
BUILDINGS, FARMS, AND MINES ARE
A FEW WAYS WE HAVE CHANGED THE
LOOK OF THE EARTH.
DID YOU KNOW THAT MOST OF THE
EARTH'S SURFACE IS COVERED WITH
WATER?
>> 70% OF THE EARTH'S SURFACE IS
COVERED BY OCEAN.
ONLY .008% OF THE EARTH'S FRESH
WATER IS FOUND IN LAKES, RIVERS,
AND STREAMS.
THAT'S THE WATER THAT WE NEED TO
LIVE.
SO, WHEN YOU THINK ABOUT THE
EARTH, THINK ABOUT THE SYSTEMS
THAT MAKE UP THE PLANET.
THE GEOSPHERE, THE SOIL,
SEDIMENTS AND SOLID AND MOLTEN
ROCK.
THE HYDROSPHERE, THE WATER ON
EARTH.
THE ATMOSPHERE, THE LEVELS OF
AIR AND GASES AROUND THE EARTH,
AND THE BIOSPHERE, ALL THE
ECO-SYSTEMS AND LIVING THINGS ON
EARTH.
>> THAT'S A LOT TO THINK ABOUT.
>> PLEASE LET ME PLAY!
>> YOU WILL GET YOUR, GO AND GET
YOUR OWN BALL.
>> OK.
YOU ARE GOING TO PLAY THAT LOOKS
LIKE THIS, I AM GOING TO PLAY
WITH ONE THAT LOOKS LIKE THE
SUN.
>> WHAT IS THAT ALL ABOUT?
YOU KNOW.
>> AND JOINING ME NOW TO ANSWER
YOUR QUESTIONS ABOUT THE EARTH
ARE VIRGINIA GILLERMAN, A
GEOLOGIST WITH THE IDAHO
GEOLOGICAL SURVEY, AND JEFFERY
JOHNSON, ASSISTANT RESEARCH
PROFESSOR OF GEOPHYSICS AT BOISE
STATE UNIVERSITY.
THANK YOU FOR JOINING US.
>> THANK YOU VERY MUCH.
>> THANK YOU.
>> THIS IS GOING TO BE FUN.
>> LET'S GO TO YOUR QUESTIONS.
>> HI, MY NAME IS JEFF, AND I GO
TO KAMIAH ELEMENTARY SCHOOL IN
KAMIAH, IDAHO, AND MY QUESTION
IS -- WHAT MAKES THE EARTH
ROTATE?
>> THE EARTH ROTATES BECAUSE
IT'S ALWAYS ROTATED, AND THAT'S,
THAT'S REALLY A PRETTY POOR
ANSWER.
BUT, IT IS INTERESTING TO NOTE
THAT THE EARTH IS ROTATING ABOUT
THE SAME RATE THAT IT IS NOW, AS
IT DID WHEN THE EARTH FORMED
4.6 BILLION YEARS AGO.
THE FACT OF THE MATTER IS, IT'S
SPINNING LIKE A TOP, AND THERE
IS NOTHING OUT THERE, NO
FRICTION THAT'S SLOWING IT DOWN,
AND IT WILL CONTINUE TO SPIN
UNTIL THE EARTH MAY BE BILLIONS,
TRILLIONS OF YEARS FROM NOW,
IMPACTS WITH ANOTHER BODY.
>> HI, I AM BILLY, AND I AM FROM
[INAUDIBLE] CHARTER SCHOOL, AND
MY QUESTION IS -- WHAT ARE
TECTONIC PLATES?
>> TECTONIC PLATES, BILLY, ARE
WHAT GEOLOGISTS CALL THE RIGID
LAYERS OF ROCK, WHICH FLOAT ON A
HOTTER AND MORE FLUID
SEMI-LIQUID ROCK UNDERNEATH.
THE TECTONIC PLATES ARE
CONSTANTLY IN MOTION, AND WHEN
ONE OF THEM DIVES UNDER THE
OTHER, LIKE ON, ON THE, THE
EASTERN, OR WESTERN COAST OF
SOUTH AMERICA, THEY CAN FORM
MOUNTAIN RANGES LIKE THE ANDES
AND VOLCANOES LIKE ECUADOR OR
SIMILAR THINGS ARE HAPPENING IN
JAPAN.
SO, IT'S, IT'S THE BOUNDARIES
BETWEEN THESE TECTONIC PLATES
THAT CREATES SOME OF OUR MOST
INTERESTING GEOLOGY.
>> AND ONE OF THE COOL THINGS
ABOUT TECTONIC PLATES IS JUST
HOW FAST THAT THEY MOVE.
TECTONIC PLATES ARE MOVING
CONSTANTLY, BUT YOU AND I, WE
CANNOT FEEL THEM.
THEY MOVE AT THE SAME SPEED AS
YOUR FINGERNAILS GROW.
>> JAMISON WOULD LIKE TO KNOW,
HOW BIG IS THE EARTH?
>> THE EARTH HAS A RADIUS OF
6,371 KILOMETERS ON AVERAGE.
THIS IS SOME 4,000 MILES IN
TERMS OF THE RADIUS.
HOW FAR IS THAT?
THAT'S ABOUT THE DISTANCE FROM
IDAHO TO NEW YORK AND BACK, AND
SO IT'S A CONSIDERABLE SIZE.
ONE THING THAT YOU MAY NOT BE
AWARE OF IS THAT THE EARTH HAS A
RADIUS THAT IS, THAT IS A LITTLE
BIT BIGGER AT THE EQUATORS THAN
AT THE POLES SO, OF THE EARTH AS
BEING A SPHERE THAT'S SLIGHTLY
SQUASHED.
>> I AM ADDISON, AND MY QUESTION
IS, WILL THE EARTH CONTINENTS
EVER MEET AGAIN?
>> THE EDGES OF THE CONTINENTS
MEET, THEY MEET THE OCEAN
PLATES, AND SOMETIMES, THEY MEET
OTHER CONTINENTAL PLATES LIKE IN
THE HIMALAYAS, BUT OVER THE LAST
COUPLE OF BILLION YEARS,
GEOLOGISTS ARE FINDING OUT, THE
EARTH'S CONTINENTS AND PLATES
HAVE MOVED TOGETHER AND THEN
BEEN DRIVEN APART SEVERAL TIMES.
SO, WE FORMED SUPER CONTINENTS
LIKE RODINIA AND PANCIA, WHERE
THE CONTINENTAL MASSES, THE LAND
THAT YOU SEE THAT HAS ROCKS THAT
HAVE MORE SILICON AND ALUMINUM
AND SANDSTONE AREAS, THOSE
CONTINENTAL AREAS HAVE BEEN
PUSHED TOGETHER INTO THE SUPER
COULD NOT NENTSZ, AND OVER TIME
THOSE WILL BREAK APART AGAIN,
SORT OF LIKE BILLIARD BALLS, YOU
KNOW.
HITTING EACH OTHER AND THEN
BOUNCING OFF EACH OTHER.
SO, THEY WILL MEET AGAIN, AND
THEY WILL BREAK APART AGAIN.
IT MAY TAKE A FEW MILLION YEARS.
>> AND IN INDIA AND ASIA RIGHT
NOW ARE COLLIDING WITH ONE
ANOTHER, BUT IT'S A SLOW MOTION
COLLISION.
THOSE TWO CONTINENTS ARE COMING
TOGETHER AT A RATE OF ONLY A FEW
INCHES A YEAR, AND THEY ARE
CAUSING THE CONTINUING UPLIFT IN
GROWTH OF THE HIMALAYA
MOUNTAINS.
>> HARRIS WOULD LIKE TO KNOW,
HOW WAS THE EARTH FORMED?
>> HARRIS, THE EARTH WAS FORMED
A LONG, LONG TIME AGO,
4.6 BILLION YEARS AGO, THE EARTH
ACCUMULATED FROM INTERSTELLAR
GASES AND DEBRIS AND ACCUMULATED
AND GREW INTO THE BLOB THAT WE
LIVE ON TODAY.
>> ALLEY WOULD LIKE TO KNOW, HOW
DID GRAVITY GET TO EARTH AND WHO
OR WHAT CREATED IT?
>> GRAVITY IS A FUNDAMENTAL
FORCE THAT EXISTS ANY TIME THAT
YOU HAVE MASS.
SO, WE HAVE GRAVITY ASSOCIATED
WITH OUR OWN HUMAN BODIES, BUT
THE EARTH'S MASS IS SO MUCH
LARGER, THAT THE GRAVITATIONAL
FORCE IS VERY MUCH NOTICEABLE.
THIS IS WHY WE DON'T FLOAT OFF
INTO SPACE.
SO, WE HAVE GRAVITY BECAUSE THE
EARTH IS VERY BIG AND MASSIVE.
OTHER PLANETS ALSO HAVE GRAVITY,
AND GRAVITY CAN EITHER BE
GREATER OR SMALLER, DEPENDING
UPON HOW BIG THE PLANETS ARE.
SO, IF YOU LIVE ON ANOTHER
PLANET THAT'S BIGGER, YOU WILL
HAVE A GREATER FORCE OF GRAVITY,
AND YOU WILL WEIGH HEAVIER.
>> HI, I'M KELLEN, AND MY
QUESTION IS -- WHAT PURPOSE DO
THE LAYERS OF THE ATMOSPHERE
SERVE?
>> WELL, KELLEN, THE ATMOSPHERE
IS REALLY CRITICAL FOR US HUMAN
BEINGS BECAUSE IT PROVIDES THE
OXYGEN THAT WE NEED TO BREATHE
AND TO LIVE FROM, AND IT ALSO
PROVIDES CARBON DIOXIDE, WHICH
PLANTS BREATHE AND USE IN PHOTO
SYNTHESIS, AND IT HAS OZONE,
THAT HELP TO PROTECT US FROM THE
SUN'S HARMFUL RADIATION.
SO, WE WOULD NOT BE HERE WITHOUT
THE ATMOSPHERE.
>> I WAS GOING TO ADD THAT THE
WEATHER IS HAPPENING IN OUR
ATMOSPHERE, AS WELL.
>> WEATHER, OF COURSE.
THAT'S A REALLY IMPORTANT
FUNCTION.
>> YOU MAY FEEL LIKE YOU ARE
STANDING STILL, BUT AS THE EARTH
SPINS, YOU ARE MOVING FAST,
DEPENDING ON WHERE YOU ARE ON
THE GLOBE, YOU COULD BE SPINNING
AT OVER 1,000 MILES PER HOUR,
AND WE ALL TRAVEL AT 67,000
MILES PER HOUR AS THE EARTH
MOVES AROUND THE SUN.
>> HI, MY NAME IS ZOE, AND MY
QUESTION IS -- HOW DOES THE
EARTH'S ATMOSPHERE COMPARE TO
OTHER PLANETS?
>> EARTH'S ATMOSPHERE IS THE
BEST ATMOSPHERE THAT WE KNOW OF
FOR SUSTAINING LIFE.
NOW, OTHER PLANETS WITHIN OUR
SOLAR SYSTEM ALSO HAVE
ATMOSPHERES.
MOST OF THEM ARE MUCH, MUCH
THINNER THAN THE EARTH'S
ATMOSPHERE, AND NONE OF THEM
HAVE OXYGEN, WHICH IS NECESSARY
FOR LIFE.
ONE OF THE SOLAR SYSTEMS PLANETS
THAT HAS A THICK ATMOSPHERE IS
VENUS, AND VENUS HAS LOTS AND
LOTS OF CARBON DIOXIDE, AND AS
FAR AS WE KNOW, THIS IS NOT A
GAS THAT'S VERY GOOD FOR MOST
TYPES OF LIFE FORMS.
>> KYLE WOULD LIKE TO KNOW IS IT
POSSIBLE TO LIVE ON ANOTHER
PLANET?
>> IT'S NOT POSSIBLE FOR HUMANS,
LIKE WE ARE, TO LIVE ON ANY OF
THE OTHER PLANETS THAT WE KNOW
ABOUT.
CERTAINLY NOT IN THIS SOLAR
SYSTEM.
THEY DON'T HAVE THE RIGHT AMOUNT
OF OXYGEN IN THE ATMOSPHERE.
SOME OF THEM ARE WAY TOO HOT.
SEVERAL HUNDRED DEGREES EVERY
DAY.
OR WAY TOO COLD.
AND, AND OUR LIFE, OUR, OUR
HUMANS AND OUR ANIMALS AND OUR
PLANTS HAVE EVOLVED UNDER THE
SPECIAL CIRCUMSTANCES ON EARTH.
SO, WITHOUT EXTRAORDINARY
MEASURES AS IN A SPACE STATION
OR SUITS, WE CANNOT LIVE ON
OTHER PLANETS IN THE SOLAR
SYSTEM.
>> I AM INDY, AND MY QUESTION IS
-- HOW DOES THE ATMOSPHERE KEEP
IN OXYGEN?
>> WELL, INDY, THE SPHERE HAS A
VERY IMPORTANT ROLE IN KEEPING
IN THE OXYGEN.
SOME OF THAT IS DUE TO CARBON
DIOXIDE AND OTHER GASES IN THE
ATMOSPHERE.
AND, AND I BELIEVE THAT SOME OF
IT IS SIMPLY DUE TO GRAVITY
BECAUSE GRAVITY STILL WOULD
EXERT SOME PULL ON, ON EVEN
GASES, IS THAT CORRECT, JEFF?
>> GRAVITY, ULTIMATELY, KEEPS
THE ATMOSPHERE NEXT TO THE
EARTH, BUT, IT'S IMPORTANT TO
NOTE THAT WE ARE LOSING OXYGEN
TO, TO, DUE TO, DUE TO TRAVEL
OUTSIDE OF OUR ATMOSPHERE.
AND, AND AS WELL AS BY
ABSORPTION OF OXYGEN IN OUR
ROCKS.
SO, THERE IS A CONSTANT BALANCE
BETWEEN PRODUCTION OF OXYGEN
FROM PLANTS AND LOSS OF OXYGEN
DUE TO ESCAPE FROM THE PLANET,
AS WELL AS THE PROCESSES WHICH
LOCK UP THAT OXYGEN IN OUR
ROCKS.
>> AND HI.
MY NAME IS CHLOE, AND I GO TO
HILLCREST ELEMENTARY SCHOOL.
HOW DOES THE VOLCANO SHOOT OUT
LAVA?
>> OH, I GET THIS ONE, CHLOE.
I LOVE TO STUDY VOLCANOES, AND I
STUDY HOW VOLCANOES PRODUCE LAVA
AND HOW THAT LAVA GETS EJECTED
FROM A VOLCANIC VENT.
SO, REALLY, THERE IS ONE QUICK
ANSWER, AND THAT IS VOLCANIC
GASES DRIVE EXPLOSIONS, AND
THOSE GASES CAN BE STEAM, CARBON
DIOXIDE, OR SULFUR DIOXIDE, BUT
PRESSURIZED GASES BLOW MATERIAL
OUT OF A VOLCANIC VENT WITH MORE
ENERGY AND MORE POWER THAN YOU
CAN EVEN IMAGINE.
>> MY NAME IS SOPHIE AND MY
QUESTION IS, HOW DO HOT SPOTS
MOVE?
>> SOPHIE HOT SPOTS DON'T REALLY
MOVE.
IT'S, ACTUALLY, THE TECTONIC
PLATES THAT MOVE OVER THE HOT
SPOTS, SO A HOT SPOT LOOKS LIKE
A PENCIL, THAT EXTENDS DEEP INTO
THE EARTH.
AND AS THE PLATE MOVES OVER IT,
IT CREATES AN APPARENT HOT SPOT
TRACK.
AND FOR EXAMPLE, THE YELLOWSTONE
HOT SPOT IS CURRENTLY UNDER
YELLOWSTONE NATIONAL PARK.
BUT 15 MILLION YEARS AGO, THE
CONTINENT WAS SITUATED SUCH THAT
HOT SPOT WAS ABOUT WHERE THE
JUNCTION OF OREGON, IDAHO, AND
NEVADA IS, IS TODAY.
WE CAN TRACK THE MOVEMENT OF THE
PLATE OVER THAT HOT SPOT BY
LOOKING AT AGES OF ROCKS, THE
PARTICULAR TYPE OF VOLCANIC
ROCK, ALONG THAT, THAT, THAT HOT
SPOT TRACK.
>> HI, I AM OSCAR, AND I WAS
WONDERING HOW COME YELLOWSTONE
IS SO GEE LOGICALLY ACTIVE AND
WHY THERE IS NO OTHER PLACE IN
THE WORLD LIKE IT.
>> YELLOWSTONE IS VERY ACTIVE.
WE THINK IT'S ACTIVE BECAUSE WE
CAN SEE IT TODAY.
BUT, THERE ARE OTHER PLACES IN
THE EARTH THAT ARE SIMILAR TO
YELLOWSTONE THAT HAVE SIMILAR
ROCKS, FOR EXAMPLE, THE, THE
VOLCANIC ZONE IN NEW ZEALAND,
WHICH IS ALSO UNDER LANE BY WHAT
GEOLOGISTS WHERE THERE IS A
LARGE MASS OF LIQUID ROCK OR
MAGMA THAT IS HIGH IN SILICON
AND ALUMINUM.
AND, AND IN THAT CASE, ALSO,
LIKE YELLOWSTONE, THE, THE HOT
MAGMA CHAMBER HAS HEATED THE
GROUNDWATER AND PRODUCED
GEYSERS, HOT POOLS, MUD POTS,
AND SIMILAR FEATURES THAT IF YOU
VISIT NEW ZEALAND, YOU CAN WALK
THROUGH.
SO, YELLOWSTONE IS ONE OF THE
PLACES THAT IS VOLCANOICALLY AND
GEOTHEY REMEMBERALLY ACTIVE
RIGHT NOW.
THERE HAVE BEEN OTHER PLACES
LIKE IT IN THE PAST, AND THERE
IS A FEW OTHER PLACES LIKE IT IN
THE WORLD TODAY.
>> I JUST LIKE TO ADD THAT
YELLOWSTONE IS SPECIAL IN THAT
IT HAS THE MOST GEYSERS IN THE
ENTIRE WORLD.
IN FACT, 50% OF EARTH'S GEYSERS
HAPPEN TO BE IN YELLOWSTONE.
IT IS WONDERFUL.
IT'S IN OUR BACKYARD, AND I AM
VERY PROUD TO BE LIVING NOT SO
FAR AWAY FROM YELLOWSTONE.
>> THE FIELD OF STUDY THAT DEALS
WITH THE REPRESENTATION AND
MEASUREMENT OF THE EARTH IS
GEOCITY.
IT IS A SCIENCE THAT GOES WAY
BACK.
>> A LONG TIME AGO IN EGYPT, A
MAN FIGURE OUT WHEN THE SUN WAS
ABOVE ONE CITY, YOU COULD STAND
AT A NEARBY CITY TO THE NORTH
AND MEASURE THE ANGLE OF THE
SHADOW SAYS AND MULTIPLY THAT BY
THE DISTANCE TO GET THE DISTANCE
AROUND THE ENTIRE EARTH.
WITH THAT, THE SCIENCE OF
GEODESY WAS BORN.
IT DEALS WITH THE MEASUREMENT
AND REPRESENTATION OF THE EARTH,
OR TO PUT IT MORE SIMPLY, THE
SCIENCE OF WHERE THINGS ARE AND
JUST AS IMPORTANTLY, WHERE THEY
HAVE BEEN AND WHERE THEY ARE
GOING.
6 THROUGH GEODESY, WE LEARN THE
SIZE AND SHAPE OF THE EARTH, THE
DIRECTION OF THE ROTATION, AND
THE DISTANCE FROM THE SUN, AND
MORE.
WE THROUGH TRIANGULATION, WE CAN
CREATE MAPS OF COUNTRIES, AND
EVEN FIGURED OUT THE EARTH IS
NOT A PERFECT SPHERE, AND AFTER
SOME ARGUMENTS AND EXPEDITIONS
TO PERU, WE MEASURED THAT IT'S
JUST A BIT THICKER IN THE
MIDDLE.
BUILDING ON THIS INFORMATION, WE
FOUND TONS OF PRACTICAL USES FOR
GEODESY.
USUALLY STARS AS A REFERENCE
POINT, AND ACCURATE WATCHES, WE
COULD RELIABLY DETERMINE
LATITUDE AND LONGITUDE SO SHIPS
COULD CROSS OCEANS TO GET TO
WHERE THEY NEEDED.
THE EXPLORERS VISITED
UNCHARTERED REGIONS, AND MAPPED
THEM AND FOUND THE TALLEST
MOUNTAIN IN THE WORLD.
LATER, ENGINEERS BUILT RAILROADS
TO GET US TO THESE PLACES.
WITH THE SAME REFERENCE SURFACE,
RAIL TUNNELS COULD BE STARTED ON
BOTH SIDES OF THE MOUNTAIN, AND
SOMEHOW MEET IN THE MIDDLE.
LIFE WAS GOOD.
ONCE WE INVENTED RADIO
TELESCOPES AND SATELLITES,
THINGS GOT EVEN BETTER.
WHEN SCIENTISTS USED A BUNCH OF
SMALL RADIO DISHES LIKE ONE BIG
ONE TO LOOK, SOMEBODY GOT THE
IDEA YOU COULD USE THESE
MEASUREMENTS TO DETERMINE VERY
ACCURATELY THE DISTANCE BETWEEN
THE TELESCOPES, AND NOW WE CAN
LOOK AT THE MOVEMENT OF THE
EARTH'S CHANGES, AND HOW THE
EARTH TRAVELS ON ITS AXIS.
SATELLITES BECAME VERY IMPORTANT
BY ANALYZING THEIR ORBITS, WE
CAN LEARN ABOUT OUR PLANET'S
CHANGING SIZE AND SHAPE AND
GRAVITY, AND BY MAKING LASER
MEASUREMENTS, WE CAN LOOK AT
CHANGES IN THE HEIGHT OF THE
OCEANS AND ICE SHEETS TO HOW THE
TIETH -- TIETS -- TIDES WORK, IS
A GEODESY HAS A HUGE IMPACT ON
OUR LIVES AND ALL BECAUSE
SOMEBODY A LONG TIME AGO DECIDED
TO LOOK DOWN A WELL.
>> I AM FENA, AND MY QUESTION IS
-- WHY WAS THERE VOLCANIC
ACTIVITY IN IDAHO'S GEOLOGIC
HISTORY BUT THERE ARE NOT ANY
VOLCANOES IN IDAHO NOW?
>> THERE HAVE BEEN PERIODS IN
THE PAST, NOTABLY, ABOUT
2 MILLION YEARS AGO, WHEN THE
VOLCANOES OF THE SNAKE RIVER
PLAIN WERE POPPING UP ALL OVER
THE PLACE.
15 MILLION YEARS AGO, WHEN THE
COLUMBIA RIVER, BASALTS POURED
OUT AND FLOWED TO THE PACIFIC
OCEAN, AND ABOUT 45 MILLION
YEARS AGO, WHEN THE CHALLIS
VOLCANIC EPISODE OCCURRED.
SO, THERE'S BEEN TIMES WHEN IT'S
BEEN MUCH MORE ACTIVE THAN IT IS
RIGHT NOW.
BUT, YOU NEVER KNOW.
MAYBE WE'LL GET A, A BIG
VOLCANIC ERUPTION TOMORROW.
>> YOU KNOW, I WOULD NOT LOSE
SLEEP OVER THE IDEA OF A BIG
VOLCANIC ERUPTION TOMORROW.
BUT, IT IS IMPORTANT TO NOTE
THAT IDAHO DOES HAVE RECENT
VOLCANIC ACTIVITY, AS EARLY AS,
AS RECENT AS 2000 YEARS AGO,
THERE WERE LAVAS THAT ERUPTED
FROM CRATERS OF THE MOON
NATIONAL MONUMENT THAT HAS VERY,
VERY FRESH LAVA FLOWS.
AND 2000 YEARS AGO IS REALLY A
BLINK OF THE EYE IN TERMS OF THE
GEOLOGIC HISTORY.
>> GABBY WOULD LIKE TO KNOW HOW
DO WE GET EARTHQUAKES?
>> EARTHQUAKES HAPPEN WHEN ROCKS
BREAK VERY, VERY QUICKLY.
WHEN THAT HAPPENS, THE EARTH
MOVES VERY RAPIDLY, AND
GENERATES SEISMIC WAVES, WHICH
WE CAN RECORD WITH, WITH
DELICATE AND HIGH FIDELITY
INSTRUMENTATION CALLED
SIZEOMETERS.
THAT IS NOTHING MORE THAN AN
INSTRUMENT THAT RECORDS THE
SHAKING OF THE GROUND WITH MUCH
MORE SENSITIVITY THAN HUMANS
CAN.
>> I AM AALIYAH AND I HAVE A
QUESTION, WHY DOES CALIFORNIA
HAVE SO MANY EARTHQUAKES AND
IDAHO HAS SO FEW.
>> YOU ARE ASKING WHY DOES IDAHO
NOT HAVE MANNY EARTHQUAKES AS
CALIFORNIA.
IT'S FOR THE SIMPLE REASON THAT
IDAHO IS LOCATED IN THE INTERIOR
OF A CONTINENT.
CALIFORNIA IS RIGHT ON THE VERY
EDGE OF WHERE NORTH AMERICA AND
PACIFIC TECTONIC PLATES MEET.
AND IT JUST SO HAPPENS THAT MOST
OF EARTH'S EARTHQUAKES HAPPEN
ALONG THESE BOUNDARIES.
THAT IS NOT TO SAY THAT IDAHO
DOESN'T HAVE ANY EARTHQUAKES OR
WON'T HAVE EARTHQUAKES IN THE
FUTURE, BUT THE NUMBER OF
EARTHQUAKES IN IDAHO IS FAR LESS
THAN IT IS IN, SAY, CALIFORNIA,
AND THE SIZE OF THE EARTHQUAKES
THAT OCCUR HERE, ARE GENERALLY
MUCH SMALLER.
THE MOST RECENT, LARGEST
EARTHQUAKES TO HAVE OCCURRED IN
IDAHO HAPPENED IN 1983.
AND IT WAS A MAGNITUDE OF 7.3
EARTHQUAKE.
BUT THEY HAPPEN VERY
INFREQUENTLY.
>> CARA ASKS, WHY DOES THE EARTH
MOVE BUT WE DON'T FEEL IT MOVE?
>> THE EARTH MOVES, AND IT MOVES
OVER ALL SORTS OF TIME SCALES,
AND IT MOVES IN VERY INTERESTING
FASHIONS.
WE DO EXPERIENCE EARTH MOVEMENTS
WHEN EARTHQUAKES OCCUR, AND THAT
IS WHEN, WHEN SUDDEN BREAKAGE OF
ROCKS CAUSE A SEISMIC WAVE TO
PROPGATE AND SHAKE IT, BUILDINGS
CAN BE KNOCKED OVER, AND THOSE
MOVEMENTS CAN BE VERY, VERY
INTENSE.
NOW, THE EARTH ALSO MOVES VERY
SLOWLY DUE TO PLATE TECTONIC
MOVEMENTS.
THOSE MOVEMENTS ARE SO VERY
SLOW, THAT MOST OF US WILL NEVER
SENSE THEM.
THOSE PLATE TECTONIC MOVEMENTS
OCCUR AT RATES OF ONLY A FEW
INCHES PER YEAR.
VERY, VERY SLOW.
>> AND, OF COURSE, THE EARTH IS
MOVING, SIMPLY BY ROTATING EACH
DAY.
BUT, IT HAPPENS ON SUCH A LARGE
MASS, AND AT SUCH A, A SLOW RATE
THAT WE DON'T FEEL IT.
>> HI, I AM JENNA, AND I AM PART
OF ANSWER -- ANTHONY CHARTER
SCHOOL, AND MY QUESTION IS WHY
IS THE SKY BLUE?
>> THE SKY IS THE BLUE BECAUSE
THE SUN WHEN RADIATES OUR
SUNLIGHT IN THE FORM OF LIGHT,
WHICH COMPRISES ALL COLORS OF
THE RAINBOW, INTERACTS WITH THE
SPHERE.
OUR ATMOSPHERE HAS OXYGEN IN IT
WHEN SCATTERS THE BLUE PORTION
OF THE VISIBLE LIGHT, AND THAT
THAT SCATTERED ENERGY COMES
DOWN, AND WE CAN SEE IT WITH OUR
EYES.
IF YOU WERE TO LOOK AT THE SUN
OUTSIDE OF THE SPHERE, IT WOULD
LOOK WHITE.
>> DEVON ASKS, HOW DID THE EARTH
GET ITS NAME?
>> I HAD TO LOOK THIS ONE UP.
AND FROM WHAT I COULD READ, THE
NAME COMES FROM AN OLD ENGLISH
WORD, CLOSE TO EARTHA, I'M NOT
SURE I'M PRONOUNCING IT RIGHT,
BUT THE TERM GOES BACK AT LEAST
OVER 1,000 YEARS, PROBABLY AT
LEAST 1500 YEARS THAT WE CAN
TRACE IT THROUGH THE LANGUAGES,
INCLUDING OLD AND MIDDLE ENGLISH
FROM SIMILAR SOUNDING WORDS.
THERE WAS, I BELIEVE, A, A
MYTHOLOGICAL GOD OF THE EARTH,
WITH A SOMEWHAT SIMILAR NAME,
BUT, EARLIER THAN THAT, I'M NOT
REAL SURE.
IT IS A GOOD QUESTION FOR A
LINGUISTICS' EXPERT.
>> AND THE EARTH IS, INDEED, THE
ONLY PLANET IN THE SOLAR SYSTEM
THAT HAS A NAME THAT DOES NOT
COME FROM GREEK OR ROMAN
MYTHOLOGY.
>> MY QUESTION IS, HOW DOES THE
MAGNETIC FIELD CHANGE FROM NORTH
TO SOUTH?
>> THIS QUESTION IS A
FUNDAMENTALLY IMPORTANT QUESTION
FOR WHICH THERE IS NO CONSENSUS
ANSWER.
WHAT WE DO KNOW IS THAT THE
EARTH'S MAGNETIC FIELD REVERSES
ITSELF.
LAST REVERSED ITSELF 700,000
YEARS AGO, AND WHEN THIS
HAPPENS, COMPASS DIRECTIONS WILL
SLIP FROM NORTH TO SOUTH, AND
THE MAY GETTIZATION WILL CHANGE
OF THE EARTH, SUCH THAT MOLTEN
ROCKS WHICH FREEZE CAN RECORD
THE HISTORY OF THE EARTH'S
MAGNIFICENTIC -- MAGNITUDIC
FIELD, AND THIS IS HOW WE KNOW
ABOUT THE BLAST TAKE TECTONIC
MOVEMENTS, AND WE CAN RECORD THE
CHANGING EARTH'S MAGNETIC FIELD.
>> VIRGINIA, BEFORE WE RUN OUT
OF TIME LET ME ASK YOU, WHY DID
YOU PICK A JOB THAT DEALS WITH
GEOLOGY?
>> I JUST LIKE ROCKS.
I LIKE BEING OUTDOORS.
AND I LIKE USING MY MIND IN
SOLVING PROBLEMS.
AND I FOUND THAT GEOLOGY WAS A
PLACE WHERE I COULD BE OUTDOORS,
AND I COULD OBSERVE THINGS, AND
I WAS USING MY MIND AT THE SAME
TIME THAT I WAS ENJOYING BEING
OUTDOORS.
SO, I JUST LIKED IT.
AND I'M LUCKY THAT I FOUND A JOB
WHERE I CAN, ACTUALLY, GET PAID
FOR DOING GEOLOGY.
>> JEFF, IF SOMEONE IS
INTERESTED IN FINDING A JOB IN
EARTH SCIENCE, WHAT SHOULD HE OR
SHE STUDY IN SCHOOL?
>> SCIENCE IS ONE OF THE CAREERS
THAT IS JUST SO EXCITING FOR A
NUMBER OF REASONS.
YOU HAVE ENTIRE FREEDOM TO
EXPLORE NEW AREAS OF RESEARCH
THAT NO ONE ELSE KNOWS ABOUT.
IN ORDER TO BECOME A SCIENTIST,
THE BEST SKILLS TO LEARN IN
SCHOOL ARE ALL SKILLS, INCLUDING
MATH, INCLUDING SCIENCE, AND
BELIEVE IT OR NOT, INCLUDING
WRITING SKILLS.
EVEN SCIENTISTS, WHO ARE THE
MARTYRS IN TERMS OF THE MATH AND
SCIENCE, NEED TO BE ABLE TO
CONVEY THEIR IDEAS TO OTHER
PEOPLE AND TELL THEIR STORY TO
THE WORLD.
>> THANK YOU, VIRGINIA AND JEFF
FOR ANSWERING QUESTIONS.
I APPRECIATE YOU TAKING THE TIME
TODAY.
>> THANK YOU, JOAN AND TO ALL
THE STUDENTS WHO SUBMITTED GREAT
QUESTIONS TODAY.
>> GREAT QUESTIONS.
KEEP STUDYING SCIENCE.
>> YES.
>> OUR THANKS, ALSO, TO THE
FOLKS HERE AT BOISE STATE
UNIVERSITY'S EARTH SCIENCE
RESEARCH LAB FOR HOSTING US.
YOU CAN LEARN LOTS MORE ABOUT
THE EARTH AND LOTS OF OTHER
SCIENCE TOPICS ON THE SCIENCE
TREK WEBSITE.
WE'LL ANSWER MORE QUESTIONS
ABOUT THE EARTH ON SCIENCE TREK
THE WEB SHOW.
IF YOU WANT TO SUBMIT A QUESTION
FOR SCIENCE TREK, IT'S EASY.
YOU AND YOUR CLASS CAN WIN
PRIZES.
YOU CAN SEND US AN EMAIL OR A
VIDEO QUESTION AND RECORD IT ON
YOUR WEB CAM OR CELL PHONE, AND
IF YOU ARE AN EDUCATOR, WE'LL
LEND YOU A CAMERA.
THE LAST PRIZE WINNER WAS DILLON
IN MRS. JACOB'S CLASS AT KAMIAH
ELEMENTARY.
SO TO FIND OUT ABOUT THE EARTH
AND HOW TO SEND IN QUESTIONS AND
WIN, GO TO THE SCIENCE TREK
WEBSITE.
EACH WEEK, CHECK OUT MY BLOG FOR
THE LATEST SCIENCE NEWS FOR
KIDS.
YOU WILL FIND IT ALL AT
IDAHOPV.ORG/SCIENCETREK.
THANKS FOR JOINING US.
WE'LL SEE YOU NEXT TIME ON
SCIENCE TREK.
>>> PRESENTATION OF SOIRG ON
IDAHO PUBLIC TELEVISION IS MADE
POSSIBLE THROUGH THE GENEROUS
SUPPORT OF THE LAURA MOORE
CUNNINGHAM FOUNDATION.
COMMITTED TO FULFILLING THE
MOORE FAMILY LEGACY OF BUILDING
THE GREAT STATE OF IDAHO.
>>> IF YOU WANT TO LEARN MORE
ABOUT THIS TOPIC OR WATCH OUR
VIDEOS, CHECK OUT THE SCIENCE
TREK WEBSITE AT