>> CAPTIONS WILL APPEAR HERE.
>> GOOD AFTERNOON.
AND WELCOME TO THE LIFELONG
LEARNING PROGRAM FOR FALL 2020.
AND WELCOME TO THE GEOLOGY AND
NATURAL DISASTERS.
AND I'VE BEEN INFORMED THIS IS
THE FIRST TRIAL RUN OF THE NEW
HYBRID FORMAT.
SO WE'RE ALL THE GUNIE PUG
TODAY.
SO HOPEFULLY EVERYTHING WORKS
OUT.
IF IT DOESN'T, IF WE'VE GOT SOME
ISSUES, JUST PLEASE BEAR WITH
US.
SO MY NAME IS HEATHER MERCHANT.
AND I'LL TELL YOU A LITTLE BIT
ABOUT MYSELF BEFORE WE BEGIN.
I HAVE A B.S. IN GEOLOGY FROM
WICHITA STATE UNIVERSITY AND AN
M.S. IN EARTH ENVIRONMENT AND
PHYSICAL SCIENCE FROM WSU
AS WELL.
MY MASTER'S RESEARCH WAS
STRUCTURAL GEOLOGY, ORIGINATING
FROM THE LARAMIDE OROGENY OF THE
BUILDING OF THE ROCKY MOUNTAINS.
I'M STILL A STUDENT AS WELL.
I'M A COUPLE CLASSES AWAY FROM
HAVING MY MBA IN MARKETING DONE.
SO I'LL PROBABLY JUST ALWAYS BE
A STUDENT.
I AM A HUGE FAN OF THE LIFELONG
LEARNING PROGRAM.
I JUST -- I THINK IT'S FANTASTIC
TO JUST ALWAYS KEEP LEARNING AND
NEW THINGS AND KEEPS YOU ACTIVE.
SO I TAUGHT OCEANOGRAPHY FOR THE
PROGRAM LAST YEAR AND I HAD A
FANTASTIC TIME.
SO THIS IS THE SECOND TIME I'M
TEACHING FOR THE PROGRAM.
AND I'M HOPING, ALTHOUGH I CAN'T
REALLY TELL WITH THE MASKS ON,
BUT I'M HOPING A LOT OF YOU ARE
THE SAME STUDENTS THAT I HAD
LAST YEAR, BECAUSE I HAD A BALL
WITH YOU GUYS.
SO LET'S GET STARTED.
OKAY.
SO THIS IS WEEK ONE.
WE'RE GOING TO COVER THE NATURAL
DISASTERS OF VOLCANOS.
I THOUGHT WE'D START OUT WITH
SOMETHING FLASHY AND A LOT OF
FUN.
SO I THINK VOLCANOES WITH THE
MOST FUN OF ALL OF THESE.
SO WE'RE GOING TO COVER SEVERAL
TOPICS.
FIRST WE'RE GOING TO DO A BASIC
OVERVIEW OF PLATE TECTONICS.
NOW, MOST OF YOU, ESPECIALLY IF
YOU'VE TAKEN A GEOLOGY OR EARTH
SCIENCE CLASS BEFORE, YOU'RE
PROBABLY FAMILIAR WITH THE
THEORY OF PLATE TECTONICS IN
SOME WAY.
BUT THIS WILL BE A GOOD, A GOOD
WAY TO BRUSH UP ON THAT.
AND BEFORE WE CAN REALLY
UNDERSTAND NATURAL DISASTERS AND
ESPECIALLY VOLCANOES, WE REALLY
HAVE TO UNDERSTAND HOW THINGS
ARE BEING DRIVEN, WHAT'S
HAPPENING, WHAT'S CAUSING THE
VOLCANOES.
SO NOT ONLY IS IT GOING TO HELP
WITH VOLCANOES, BUT THEN LATER
ON IN THE OTHER CLASSES WE'RE
GOING TO NEED TO KNOW A LITTLE
BIT OF THAT PLATE TECTONICS
AS WELL.
SO I THOUGHT WE'D START WITH
THAT.
WE'RE NOT GOING TO GET TOO
IN-DEPTH WITH IT BECAUSE THAT
COULD BE A WHOLE CLASS IN
ITSELF.
SO WE'RE JUST GOING TO LEARN THE
BASICS OF IT.
AND THEN WE ALL HAVE AN IDEA OF
WHAT VOLCANOES ARE.
YOU KNOW, WE ALL THINK HAWAII
USUALLY.
BUT WE'RE GOING TO FIND OUT
EXACTLY WHAT ARE VOLCANOES.
YOU KNOW, WHAT DEFINES THEM?
AND WE'LL MOVE ON TO THE
DIFFERENT TYPES OF VOLCANOES.
AND HOW TO LIVE WITH VOLCANOES.
HOW DO THEY AFFECT OUR LIVES?
HOW DO -- EVEN WHEN WE'RE FAR
AWAY FROM A VOLCANO, LIKE WE ARE
IN KANSAS, YOU KNOW, ARE
VOLCANOES AFFECTING US RIGHT
NOW?
AND THEN THE FUN PART, WE'RE
GOING TO GO OVER HISTORIC
VOLCANIC CATASTROPHES.
AND THEN WE'LL MOVE INTO
ERUPTION FORECASTING.
SO GEOLOGY AND PHYSICAL SCIENCE,
EARTH SCIENCE, YOU CAN LEARN
ABOUT IT, YOU CAN READ ABOUT IT,
YOU CAN LOOK AT PICTURES OF IT,
BUT IT'S BEST LEARNED WHEN YOU
CAN EXPERIENCE IT.
SO I'VE -- SINCE WE CAN'T GO OUT
AND ACTUALLY GO VISIT A VOLCANO
OF COURSE, SO I'VE PUT IN A FEW
LITTLE SHORT LIKE TWO- TO
THREE-MINUTE VIDEOS THROUGHOUT
SO WE CAN ACTUALLY SEE SOME OF
THE STUFF THAT'S GOING ON.
OKAY, SO WE'RE GOING TO START
WITH OUR OVERVIEW OF PLATE
TECTONICS.
SO BEFORE PLATE TECTONICS WAS A
THEORY, THERE WAS ALFRED
WEGENER.
HE WAS A GERMAN SCIENTIST AND
EXPLORER.
AND HE STARTED NOTICING THAT THE
CONTINENTS LOOKED LIKE PIECES OF
A PUZZLE THAT COULD BE PUSHED
TOGETHER.
HE WASN'T THE FIRST ONE TO
NOTICE THIS.
GOING BACK ABOUT 400 YEARS AGO,
SCIENTISTS STARTED THINKING THAT
THEY COULD HAVE POSSIBLY FIT
TOGETHER AND MAYBE BROKEN APART.
BUT ALTREAD WEGENER WAS THE
FIRST -- ALFRED WEGENER WAS THE
FIRST ONE WHO STARTED PUTTING
LINES OF EVIDENCE AND CREATING
AN ACTUAL THEORY OUT OF THIS.
SO IN ADDITION TO LOOKING LIKE
PUZZLE PIECES THAT COULD BE
PUSHED TOGETHER, HE NOTICED THAT
THERE WERE FOSSIL LINES THAT
WENT ACROSS THE CONTINENTS.
NOT JUST ANIMALS, BUT PLANTS
AS WELL.
AND IF ANY OF YOU ARE GARDENERS,
I LOVE TO GARDEN, BUT IF ANY OF
YOU ARE GARDENERS, YOU KNOW THAT
WE'RE IN ZONE 6B.
NOW, IF WE TAKE A PLANT FROM
ZONE 10 LIKE A TROPICAL HIBISCUS
AND WE PLANT IT IN OUR ZONE,
COME WINTERTIME IT'S GOING TO
FREEZE AND DIE.
SO PLANTS HAVE A VERY, VERY
DEFINED ECOSYSTEM OR ENVIRONMENT
IN WHICH THEY CAN LIVE AND
THRIVE.
WELL, AS YOU CAN SEE FROM THIS
IMAGE, THERE'S A FOSSIL PLANT,
AND HE FOUND IT NOT ONLY IN
ANTARCTICA, THERE WERE FOSSILS
OF IT IN AUSTRALIA, INDIA,
AFRICA, AND SOUTH AMERICA.
AND THESE WERE ALL FOUND IN THE
SAME AGED ROCKS.
SO HOW COULD THE SAME PLANT LIVE
IN SO MANY DIFFERENT CLIMATES?
IT JUST DIDN'T MAKE SENSE!
SO THAT WAS ANOTHER LINE OF
EVIDENCE FOR THE CONTINENTS ALL
BEING TOGETHER IN A SIMILAR
CLIMATE AT ONE POINT IN TIME.
THEN HE ALSO FOUND GLACIAL
SEDIMENTS IN THE TROPICS.
THE TROPICS ARE VERY WARM.
THERE SHOULDN'T BE GLACIAL
SEDIMENTS.
THEY WOULD HAVE MELTED.
SO THESE ALL LED HIM TO BELIEVE
THAT DEFINITELY THE CONTINENTS
WERE TOGETHER AT SOME POINT.
THE PROBLEM WAS, HE DIDN'T KNOW
HOW.
HOW DID THEY GET TOGETHER?
HOW DID THEY BREAK APART?
SO HE LACKED A DRIVER FOR HIS
THEORY.
NOW, EUROPEAN GEOLOGISTS AT THE
TIME, THEY THOUGHT, WELL, THIS
IS GOOD ENOUGH, YOU KNOW, HIS
THEORY LOOKS PRETTY SOUND, YOU
KNOW, MAYBE HE DOESN'T KNOW HOW
THEY MOVE TOGETHER, BUT, YOU
KNOW, IT SOUNDS PRETTY GOOD, I
THINK WE CAN GO FORWARD WITH
THAT AS A THEORY AND THEY PRETTY
MUCH ACCEPTED IT, FOR A WHILE.
AMERICAN GEOLOGISTS, THEY DIDN'T
AGREE WITH THAT.
THEY JUST SAID, NO, YOU HAVE TO
HAVE A WAY THAT IT'S MOVING.
THERE'S JUST NO WAY THAT
CONTINENTAL CRUST CAN MOVE AND
PLOW THROUGH THE HEAVY BASALTIC
OCEAN CRUST.
SO YOU GOTTA HAVE A DRIVER.
SO BETWEEN THE 1910s AND THE
1950s, SCIENCE ULTIMATELY
REJECTED HIS THEORY.
AND HE WAS AN EXPLORER AND LATER
IN LIFE HE WAS EXPLORING AND
SADLY HE FROZE TO DEATH.
AND IT'S VERY SAD BECAUSE HE
FROZE TO DEATH BEFORE HE EVER
SAW HIS THEORY OF CONTINENTAL
DRIFT BEING INCORPORATED INTO
THE THEORY OF PLATE TECTONICS
AND HAVE IT ACCEPTED BY SCIENCE.
SO FAST FORWARD TO WORLD WAR II
AND WE HAVE A GEOLOGIST NAMED
HARRY HESS.
HE WAS ALSO A CAPTAIN IN THE
NAVY AND HE WAS ASSIGNED TO A
SHIP THAT WAS USING NEW
TECHNOLOGY FOR THE TIME.
IT WAS SONAR.
AND HE -- AT THAT TIME IN
HISTORY, IT WAS STILL BELIEVED
PRETTY MUCH THAT THE OCEAN BASIN
WAS TRULY WHAT YOU WOULD THINK
OF AS A BASIN.
VERY SMOOTH, VERY FLAT, YOU
KNOW, NOT MUCH GOING ON, JUST
MAYBE SOME SEDIMENTS
PRECIPITATING OUT OF THE WATER
COLUMN.
AND CREATING A VERY, VERY FLAT,
UNEVENTFUL OCEAN BOTTOM.
WELL, WITH HIS SONAR, HE WAS
NOTICING THAT THE WATER WAS
DIFFERENT DEPTHS.
SO THE BASIN IN SOME POINTS WAS
VERY DEEP, OTHER POINTS IT WAS
VERY SHALLOW WHERE IT SHOULD
HAVE BEEN DEEP.
SO HE ULTIMATELY DISCOVERED A
MOUNTAIN RANGE ON THE BOTTOM OF
THE OCEAN, AND THIS WAS THE
MID-ATLANTIC RIDGE.
NOW, ALREADY BEING A GEOLOGIST,
HE WAS THINKING IN SCIENTIFIC
TERMS AND EARTH SCIENCE TERMS.
SO HE THOUGHT HOW CAN THERE BE A
MOUNTAIN RANGE ON THE BOTTOM OF
THE OCEAN?
IT HAD TO COME FROM SOMEWHERE.
SO HE THOUGHT MAYBE, MAYBE LAVA
IS COMING UP AND BUILDING THESE
MOUNTAINS.
AND AS IT COMES UP, IT WOULD
PUSH, PUSH THE REST OF THE BASIN
OUTWARD.
AND IT WOULD JUST GET BIGGER AND
BIGGER AND BIGGER.
SO HE ALSO UNDERSTOOD THAT IF
YOU'RE CREATING CRUST AND YOU'RE
GETTING BIGGER AND BIGGER, THAT
WOULD MEAN THAT THE EARTH WOULD
BE GETTING BIGGER AND BIGGER.
BUT IT'S NOT.
SO WHERE IS IT GOING?
SO WHERE YOU CREATE SOMETHING,
YOU HAVE TO DESTROY IT IF YOU'RE
GOING TO STAY THE SAME SIZE AND
STAY IN EQUILIBRIUM.
SO HE DISCOVERED THESE TRENCHES
WHERE IT WAS VERY, VERY DEEP,
AND HE DISCOVERED SUBDUCTION.
THAT IS WHERE THE CRUST GETS
SUBDUCTED UNDER ANOTHER PLATE.
SO IT WOULD GO LIKE THAT, DOWN
UNDER.
SO YOU'D HAVE CREATION AT THE
CONTINENTAL RIDGE AND THEN
DESTRUCTION AT THE TRENCH.
AND THIS KEPT THE EARTH THE SAME
SIZE.
AND IT ALSO WAS THE DRIVER FOR
MOVING THE CONTINENTS AROUND THE
GLOBE.
AND SO BEFORE WE GET ANY
FARTHER, I WANTED TO SHOW THE
LAYERS OF THE EARTH.
AND WHERE THE MOVEMENT, WHERE
THIS MOVEMENT IS TAKING PLACE.
SO AT THE DEEPEST POINTS IN THE
MIDDLE OF THE EARTH, WE HAVE THE
INNER CORE.
THE INNER CORE, ALTHOUGH IT'S AT
THE HOTTEST LOCATION, YOU WOULD
THINK IT WOULD BE MELTED.
BUT DUE TO THE PRESSURE ABOVE
IT, IT'S ACTUALLY A SOLID.
IT'S MOSTLY IRON AND NICKEL.
THEN WHEN YOU GET TO THE OUTER
CORE, THE PRESSURE IS FAR LESS,
SO IT'S ABLE TO MELT.
SO IT'S BELIEVED THAT THAT'S
MOLTEN.
AND THEN WE MOVE UP TO THE
MANTLE.
IT'S STILL HOT, BUT NOT HOT
ENOUGH TO BE COMPLETELY LIQUID.
SO IT'S SOFT.
IT'S PLIABLE.
IT CAN MOVE.
AND THAT'S WHERE THE MAGMA IS
COMING FROM IN THE UPPER MANTLE
AND IT BREAKS THROUGH THE CRUST.
SO NOW I'M GOING TO SHOW A
LITTLE ANIMATED FEATURE AND IT
WILL SHOW YOU SEAFLOOR SPREADING
AND HOW IT MOVES OUT.
IT ALSO IS GOING TO DEMONSTRATE
THE SWITCH IN POLARITY, AND THIS
IS ANOTHER FACT THAT HELPED TO
PROVE PLATE TECTONICS.
AT DIFFERENT TIMES IN HISTORY,
AND IT'S NOT KNOWN WHY, IT'S A
MYSTERY, THE POLARITY OF THE
EARTH SWITCHES.
NORTH WILL BECOME SOUTH, AND
SOUTH BECOMES NORTH.
THIS IS RECORDED IN THE ROCK
RECORD, THE POLARITY OF NORTH
VS. SOUTH.
SO AT THE SPREADING CENTERS,
IT'S LIKE ZEBRA STRIPES, BUT
THEY'RE MIRRORED ON BOTH SIDES.
SO THAT DEMONSTRATES THAT
SOMETHING IS COMING UP FROM THE
CENTER AND MOVING OUT BECAUSE
YOU WOULD HAVE ROCKS THAT ARE
FACING NORTH COMING OUT, MOVING
OUT, AND THEN SOUTH, AND THEN
NORTH.
SO YOU GET THESE STRIPING EFFECT
ON EITHER SIDE.
AND THAT'S WHAT THIS ANIMATION
IS GOING TO DEMONSTRATE.
THE INTERNET IS JUST A LITTLE
SLOW IN HERE.
THEY TAKE JUST A FEW SECONDS TO
START.
SO YOU CAN SEE IT'S SPREADING
AND IT'S COMING UP AND THE
COMPASS IS SHOWING YOU WHEN IT
SWITCHES POLARITY.
AND IT GIVES THAT STRIPING
EFFECT.
SO IT'S PUSHING THE CONTINENTS
AWAY AND IT'S BUILDING THIS
OCEAN BASIN.
OKAY.
AND THAT LEADS US TO THE THEORY
OF PLATE TECTONICS.
AND BY DEFINITION, IT IS THE
THEORY THAT EARTH'S OUTER SHELL
IS DIVIDED INTO SEVERAL PLATES
THAT GLIDE OVER THE MANTLE,
DRIVEN BY SEAFLOOR SPREADING.
AND SINCE THE TIME WHEN HARRY
HESS DISCOVERED PLATE TECTONICS,
ALL THE ADVANCES IN TECHNOLOGY
AND SCIENCE, THEY'VE HELPED TO
SUPPORT THIS THEORY.
SO FAR, THERE'S BEEN NOTHING TO
CONTRADICT IT.
SATELLITE IMAGERY HAS BEEN A
HUGE HELP.
IT ACTUALLY DEMONSTRATES HOW
FAST AND WHERE THE PLATES ARE
MOVING, AND THIS IS COINCIDING
WITH WHERE WE BELIEVE THE
SUBDUCTION ZONES ARE.
SO SO FAR, EVERYTHING HAS
SUPPORTED IT.
HERE IS A SHORT LITTLE VIDEO
THAT'S GOING TO SORT OF SUM UP
PLATE TECTONICS, AND YOU CAN GET
A VISUAL OF HOW THINGS ARE
ACTUALLY MOVING AND WHAT'S GOING
ON.
>> DURING WORLD WAR II,
SCIENTISTS AT SEA WERE USING
SOPHISTICATED ECHO TECHNOLOGY TO
TRACK SUBMARINES.
WHEN THEY TURNED UP SURPRISING
INFORMATION ABOUT THE OCEAN
FLOOR.
THERE, THEY FOUND A STRETCH OF
UNDERWATER RIDGES MADE OF
CONTINUALLY ERUPTING VOLCANOES.
>> THE MID-OCEAN RIDGES FORM
WHEN MOLTEN ROCK RISES FROM
INSIDE THE EARTH, AND THEN
PUSHES THE CRUST APART.
>> A VAST SPREADING SEAFLOOR
STRONG ENOUGH TO MOVE THE
CONTINENTS.
NOT ONLY IS NEW CRUST FORMED AT
MID-OCEAN RIDGES, BUT IT DIPS
BACK DOWN AGAIN INTO THE
INTERIOR OF THE EARTH.
>> YOU PUT THIS ALL TOGETHER,
AND WHAT YOU GET IS PLATE
TECTONICS, THE IDEA THAT THE
EARTH'S CRUST CAN BE BROKEN UP
INTO LARGE PIECES, OR PLATES,
THAT CONSIST OF BOTH CONTINENTS
AND ALSO PIECES OF OCEANIC
CRUST, MOVING TOGETHER OVER THE
FACE OF THE EARTH.
>> WHEN TWO PLATES COLLIDE,
SOMETIMES ONE IS PUSHED DOWNWARD
AND MELTS INTO MAGMA.
EVENTUALLY THIS RED-HOT MATERIAL
RISES TO THE SURFACE AND
EXPLODES.
CREATING A VOLCANO.
SO NEW CRUST IS BORN AT
MID-OCEAN RIDGES AND DESTROYED
AT DEEP OCEAN TRENCHES, LIKE A
NEVER-ENDING CONVEYER BELT.
AND TWO PLATES SIMPLY NUDGING
EACH OTHER CAN CAUSE CAT TRAFFIC
RESULTS, LIKE WHEN THE SAN
ANDREAS FAULT SLIPPED IN 1906.
HOW FAST DO THE PLATES MOVE?
IF YOU LIVE IN THE U.S., YOU'RE
PROBABLY STANDING ON THE NORTH
AMERICAN PLATE.
IN THE COURSE OF ONE YEAR, THE
GROUND UNDER YOUR FEET WILL MOVE
ABOUT 2 INCHES.
AND OVER LONG PERIODS OF TIME,
THAT'S ENOUGH TO RE-SHAPE THE
EARTH, BUILD MOUNTAINS, TRIGGER
EARTHQUAKES AND CREATE
VOLCANOES.
HEATHER: HERE WE CAN SEE IT'S A
MAP OF THE GLOBE, AND IT SHOWS
WHERE THE PLATES ARE, THE -- AND
THE PLATE BOUNDARIES AND WHAT
TAPE OF BOUNDARIES THEY ARE.
SO THERE'S DIFFERENT TYPES OF
BOUNDARIES.
AND THE INTERESTING THING IS, WE
TEND TO THINK, WHEN WE THINK OF
A PLATE, IN OUR MIND, WE THINK
OF THE SHAPE OF A CONTINENT, BUT
THE PLATE ENCOMPASSES THE
CONTINENT AND OCEAN BASIN AROUND
IT, OR A PLATE COULD SIMPLY BE
OCEAN BASIN.
AND THE PLATES ARE NOT ALWAYS --
THEY'RE NOT ALWAYS STATIC.
THEY'VE CHANGED THROUGHOUT TIME.
SOME OF THEM ARE VERY OLD INDEED
AND THEN OTHERS ARE FAIRLY NEW.
SO IT JUST DEPENDS HOW THEY'RE
BREAKING APART, WHERE NEW CRUST
IS BEING CREATED.
SO THEY CHANGE OVER TIME.
BUT WE CAN SEE THE NORTH
AMERICAN PLATE AND THERE'S A
LITTLE TINY PIECE OF CALIFORNIA
THAT'S ACTUALLY SITTING ON THE
PACIFIC PLATE.
SO ALL OF OUR COUNTRY IS NOT ON
ONE PLATE, AND THIS IS WHY WE
HAVE EARTHQUAKES IN CALIFORNIA.
THIS IS A TRANSFORM FAULT.
SO WE'LL GET INTO THE DIFFERENT
TYPES OF PLATE BOUNDARIES IN A
MINUTE.
BUT THIS PARTICULAR ONE,
BASICALLY THEY'RE SLIDING PAST
EACH OTHER.
NOTHING IS BEING CREATED,
NOTHING IS BEING DESTROYED AT
THIS POINT, THEY'RE JUST SLIDING
PAST EACH OTHER.
AND THE PACIFIC PLATE IS MOVING
UP WHILE THE NORTH AMERICAN ONE
IS COMING DOWN.
SO WHAT HAPPENS IS CONTINENTS
ARE NOT SMOOTH.
SO THEY'LL GET KIND OF STUCK AND
THEY CAN'T MOVE AND THEN ALL OF
A SUDDEN THE PRESSURE BREAKS
LOOSE AND THEN THAT'S WHEN WE
HAVE AN EARTHQUAKE.
AND THAT CAN BE A SMALL ONE OR
IT CAN BE A GIGANTIC ONE.
IT JUST DEPENDS HOW MUCH
PRESSURE AND HOW MUCH ROCK IS
MOVING AND BEING BROKEN OFF.
SO A FUN FACT IS, AND NONE OF US
WILL EVER SEE IT, BUT AT SOME
POINT IN TIME, LOS ANGELES AND
SAN FRANCISCO WILL BE
SIDE-BY-SIDE, SO THEY'LL
BASICALLY BE THE SAME CITY.
IF THEY'RE STILL AROUND.
SO LET'S SEE.
AND YOU CAN SEE LIKE ON THE
AFRICAN PLATE, IT'S AFRICA, BUT
IT ALSO INCLUDES A LOT OF OCEAN
AROUND IT.
IT'S ACTUALLY IN A SIMILAR SHAPE
TO THE CONTINENT.
BUT IT INCLUDES A LOT OF THAT
OCEAN BASIN.
AND ON THE SOUTH AMERICAN PLATE,
YOU CAN SEE ON THE WESTERN COAST
IT'S SHOWING THAT THERE'S A
SUBDUCTION ZONE RIGHT THERE.
SO THE PLATES ARE COMING
TOGETHER, AND THE NAZCA PLATE IS
GOING UNDERNEATH THE SOUTH
AMERICAN PLATE, AND THAT'S WHERE
WE GET THE ANDES MOUNTAINS.
SURE.
OKAY.
SO THERE'S THREE DIFFERENT TYPES
OF PLATE BOUNDARIES.
AND THE FIRST KIND IS DIVERGENT.
SO THINGS ARE DIVERGING, THEY'RE
SEPARATING, THEY'RE MOVING
APART.
THIS IS WHAT THE MID-ATLANTIC
RIDGE WOULD BE.
THIS IS THE TYPE OF BOUNDARY IT
IS.
SO WE'RE CREATING NEW CRUST,
WE'RE MOVING APART.
THIS USUALLY OCCURS ALONG
SPREADING CENTERS WHERE MAGMA IS
BEING PUSHED UP FROM THE MANTLE.
IT CAN CREATE VOLCANOES,
VOLCANIC ISLANDS, AND IT CAN
ALSO CREATE RIFT VALLEYS.
SO USUALLY IT OCCURS WHERE TWO
OCEAN BASINS ARE COMING
TOGETHER.
BUT IT CAN ALSO OCCUR ON A
CONTINENT, IN BETWEEN TWO
CONTINENTAL CRUSTS.
ONE PLACE WHERE THAT'S HAPPENING
IS IN THE EAST-AFRICAN RIFT
VALLEY, AND A FEW YEARS -- IT'S
IN ETHIOPIA, MOSTLY.
AND A FEW YEARS AGO, THAT WAS ON
THE NEWS BECAUSE THEY HAD A
REMARKABLE MOVEMENT IN JUST A
FEW HOURS, IT MOVED FEET.
SO BASICALLY WHAT'S HAPPENING IS
THE AFRICAN CONTINENT IS BEING
TORN APART IN THAT LOCATION, AND
AS IT'S MOVING OUTWARD, THE
OCEAN IS RUSHING IN.
SO AT SOME POINT IN HISTORY, IN
THE FUTURE, IT'S ACTUALLY GOING
TO BECOME AN OCEAN, A NEW OCEAN.
SO IT'S VERY EXCITING AND THAT'S
PLATE TECTONICS THAT WE CAN
ACTUALLY SEE AND WITNESS RIGHT
NOW.
ANOTHER LOCATION WHERE THAT
OCCURS IS IN ICELAND.
YOU CAN GO DIVING IN ICELAND,
AND YOU CAN BE RIGHT IN BETWEEN
WHERE THE EURASIAN PLATE IS
PULLING AWAY FROM THE NORTH
AMERICAN PLATE.
SO YOU CAN DIVE DOWN AND YOU CAN
TOUCH BOTH -- BOTH PLATES AT
ONCE.
SO YOU CAN BE IN NORTH AMERICA
AND EURASIAN AT THE -- EURASIA
AT THE SAME TIME.
SO IT'S A FUN AREA.
THAT'S ALSO WHY ICELAND IS SO
WARM.
THEY HAVE A LOT OF HOT SPRINGS.
IT'S WARM.
IT'S VERY GREEN.
IT'S FROM THAT VOLCANIC ACTIVITY
IN THE AREA.
AND THEN WE HAVE CONVERGENT
PLATE BOUNDARIES.
THEY'RE A LITTLE MORE
COMPLICATED THAN DIVERGENT.
THERE'S ACTUALLY THREE DIFFERENT
TYPES OF THEM.
SO WHEN THINGS ARE COMING
TOGETHER, YOU COULD HAVE A
CONTINENT COMING TOGETHER WITH
AN OCEAN.
SO YOU HAVE CONTINENTAL CRUST
HITTING UP AGAINST OCEANIC
CRUST.
WELL, WHEN TWO THINGS HIT UP
TOGETHER THAT'S A LOT OF FORCE
AND IT'S GOING TO HAVE TO GO
SOMEWHERE.
IT'S EITHER GOING TO HAVE TO GO
UP OR GO DOWN.
AND CONTINENTAL CRUST IS VERY
LIGHT WEIGHT, IT'S VERY BUOYANT.
AND THAT'S BECAUSE OF THE
MINERALS IN IT.
WE CALL IT FELCIC.
SO THERE'S A LOT OF POTASSIUM
FELDSPAR, THERE'S A LOT OF
SILICA IN IT.
IT'S A LOT OF GRANITE MOSTLY.
IT'S VERY LIGHT, IT'S VERY
BUOYANT.
OCEANIC CRUST IS VERY DARK.
IT'S MAFIC.
SO THAT'S MAGNESIUM AND IRON.
SO IT'S VERY DENSE, IT'S VERY
HEAVY.
SO WHEN YOU HAVE SOMETHING
THAT'S LIGHT COMING UP AGAINST
SOMETHING THAT'S HEAVY, AND ONE
OF THEM HAS TO SINK, THE HEAVY
ONE IS GOING TO SINK.
SO IT GETS PUSHED UNDERNEATH THE
CONTINENTAL CRUST.
SO AS IT'S GOING DOWN, AS IT
SLIDES, YOU CAN SEE FROM THERE
IT'S SLIDING DOWN.
AND AS IT GETS DEEPER AND
DEEPER, IT STARTS TO GET HOTTER
AND HOTTER.
AS SO, THE CRUST STARTS TO MELT.
EVENTUALLY IT BECOMES MAGMA.
AND IT HAS TO COME UP.
SO THAT'S WHERE WE GET VOLCANIC
ARC.
SO LIKE A SERIES OF VOLCANOES ON
THE CONTINENT.
THEN WE CAN HAVE A CONTINENT
COMING UP AGAINST A CONTINENT.
SO THEY'RE BOTH LIGHT, THEY'RE
BOTH GRANITE.
SO JUST FROM PUSHING, MOSTLY
WHAT YOU'RE GOING TO HAVE IS
MOUNTAIN BUILDING.
YOU'RE GOING TO JUST CRUMPLE
UPWARD.
NOW, A LITTLE BIT OF IT'S GOING
TO GET PULLED DOWN UNDERNEATH
THE OTHER ONE.
NOT A WHOLE LOT.
BUT A LITTLE BIT.
AND ONCE IN AWHILE YOU CAN GET A
LITTLE BIT OF VOLCANIC ACTIVITY.
BUT THAT'S PRETTY RARE.
MOSTLY YOU'RE GOING TO JUST GET
MOUNTAIN BUILDING.
AND THEN YOU CAN ALSO HAVE OCEAN
TO OCEAN.
AND THIS IS VERY RARE.
IT DOESN'T HAPPEN THAT OFTEN.
BUT IT CAN HAPPEN.
AND THE OLDER BASIN, WHICHEVER
PLATE IS OLDER, IT'S GOING TO BE
COLDER.
IT'S GOING TO BE COOLER.
AND SO WHEN THINGS ARE COLD AND
COOL, THEY'RE MORE DENSE,
THEY'RE HEAVIER.
SO THE OLDER PLATE IS GOING TO
SUBDUCT UNDER THE YOUNGER PLATE.
AND THIS CAUSES EARTHQUAKES, IT
CAN ALSO CAUSE VOLCANISM.
THIS IS HOW THE ALEUTIAN ISLANDS
WAS CREATED, AN OCEAN COMING UP
AGAINST AN OCEAN.
AND THERE'S A CYCLE TO DIVERGING
AND CONVERGING.
WE OPEN UP OCEAN BASINS AND WE
CAN CLOSE OCEAN BASINS.
SO IF YOU HAVE AN OCEAN COMING
UP AGAINST AN OCEAN AND ONE SIDE
IS GETTING SUBDUCTED, YOU'RE
GOING TO SUBDUCT DOWN UNTIL
THERE'S ALMOST NOTHING LEFT, AND
THEN THEY'RE GOING TO CONTINUE
TO COME TOGETHER UNTIL THE REST
OF THAT OCEAN IS SQUEEZED OUT
AND PRETTY SOON YOU'RE GOING TO
HAVE CONTINENT UP AGAINST
CONTINENT.
AND SO THE SAME GOES FOR WHEN
YOU'RE OPENING UP.
IF YOU OPEN TWO CONTINENTS UP,
YOU'RE EVENTUALLY GOING TO
CREATE AN OCEAN BASIN.
SO THIS WHOLE CYCLE OF OPENING
AND CLOSING OCEAN BASINS IS
CALLED A WILSON CYCLE.
AND THEN THE THIRD KIND IS THE
TRANSFORM PLATE BOUNDARY.
AND THIS IS WHAT WE TALKED OF
BEFORE, LIKE CALIFORNIA, WITH
THE EARTHQUAKES.
SO THE TWO PLATES ARE JUST
SLIDING HORIZONTALLY PAST EACH
OTHER.
SO THIS IS WHAT THE SAN ANDREAS
FAULT IS.
AND THESE DO NOT CAUSE ANY
VOLCANISM, BUT THEY DO CAUSE
EARTHQUAKES.
THEY CAN CAUSE SOME MET MORPHISM
IN ROCKs BECAUSE THE MOVING
PAST EACH OTHER, IT DOES CREATE
HEAT.
IT DOESN'T CREATE ENOUGH HEAT TO
COMPLETELY MELT SOMETHING, BUT
IT CAN JUST WARM UP THE ROCKS TO
CHANGE THEIR SHAPE AND CONVERT
THE MINERALS.
SO BEFORE WE FINISH UP WITH
PLATE TECTONICS, THERE'S JUST A
FEW LITTLE FUN FACTS.
SO IN THAT -- IN THAT VIDEO THAT
WE WATCHED, THEY WERE SHOWING
THAT THE PLATES MOVE ABOUT 1 TO
2 INCHES PER YEAR.
WELL, A MORE FUN WAY OF SAYING
THAT, THAT WE USUALLY USE, IS TO
REMEMBER IT, IS THEY MOVE AT THE
SAME RATE AS YOUR FINGERNAILS
GROW.
SO YOU COULD WATCH YOUR
FINGERNAILS, AND AS THEY GROW,
THAT'S ABOUT HOW FAR YOU'VE
MOVED ON THE PLATE.
THE EURASIAN PLATE IS THE
SLOWEST, AND THE PACIFIC PLATE
IS THE FAST ETC.
SO PLATE -- FASTEST.
SO PLATES DON'T NECESSARILY MOVE
AT THE SAME RATES.
BUT ON AVERAGE, IT'S ABOUT 1 TO
2 INCHES A YEAR.
AND SO IN AN ENTIRE LIFETIME,
YOU'LL BE APPROXIMATELY 6 TO
13 FEET IN A DIFFERENT LOCATION
IF YOU'RE LIVING IN THE SAME
CITY, YOU'LL BE ABOUT 6 TO
13 FEET IN A DIFFERENT DIRECTION
THAN YOU WERE WHEN YOU WERE
BORN.
OAK.
SO NOW WE'RE GOING TO MOVE ON TO
WHAT ARE VOLCANOES.
SO A VOLCANO CAN BE ANYTIME THE
EARTH'S CRUST IS RUPTURED OR
CRACKED AND HOT MAGMA FROM BELOW
IS COMING UP.
THE OFFICIAL DEFINITION IS ANY
HILL OR MOUNTAIN CONSTRUCTED BY
THE EXTRUSION OF LAVA OR ROCK
FRAGMENTS FROM A VENT.
AND SHORT HERE'S A SHORT LITTLE
VIDEO SO WE CAN SEE SOME FUN.
IT WILL SHOW A FEW VOLCANOES
ERUPTING AND SORT OF GIVE US
BRIEF DESCRIPTION.
>> OUR PLANET HAS A VIOLENT
SOUL.
MAJESTIC AND OFTEN DESTRUCTIVE,
VOLCANIC EXPLOSIONS RATTLE OUR
COLLECTIVE IMAGINE MAKE.
KRAKATOA, MT. ST. HELENS, ETNA,
THE IMAGES SIMULTANEOUSLY STRIKE
FEAR AND AWE IN OUR HEARTS.
BUT HOW DID THESE GIANT
MOUNTAINS FORM?
AND WHETHER DOES ALL THAT
DESTRUCTIVE FORCE COME FROM?
AT LET'S 50 ERUPTIONS ROCK THE
EARTH EACH YEAR, MEANING OUR
PLANET IS LITERALLY BURSTING
APART AT THE SEAMS!
THE EARTH'S CRUST IS MADE UP OF
ABOUT 17 SLAPS OF LAND CALLED
TECTONIC PLATES THAT FLOAT ON
THE SUPERHEATED MAGMA THAT MAKES
UP MOST OF THE PLANET'S
INTERIOR.
MAGMA IS THE EARTH'S LIFEBLOOD,
CHURNING REST LIVELESSLY BENEATH
THE CRUST.
AND WHEREVER IT CAN, IT'S TRYING
TO BURST THROUGH.
IT'S AT THESE SPOTS THAT SCROLL
KIND'S FORM.
 -- VOLCANOES FORM.
OUR PLANET IS HOME TO SOME 500
ACTIVE VOLCANOES.
WHILE SOME VOLCANOES, LIKE THOSE
IN HAWAII, BREAK THROUGH A THIN
POINT IN THE CRUST CALLED A HOT
SPOT, THE VAST MAJORITY OF
VOLCANOES OCCUR ON ACTIVE FAULT
LINES WHERE PLATE TECTONICS
MEET.
THE MOST VOLATILE REGION IS THE
RING OF FIRE, A GEOLOGICAL FAULT
THAT RIMS THE PACIFIC OCEAN AND
HOLDS ROUGHLY 75% OF ALL THE
EARTH'S VOLCANOES.
TYPICALLY, VOLCANOES TAKE ONE OF
TWO FORMS, SHIELD VOLCANOES,
WIDE AND BROAD WITH LAVA USUALLY
SLOWLY OOZING OUT OF THEM, AND
COMPOSITE OR STRATOVOLCANOS,
STEEPER AND MORE VIOLENT.
WHEN HOT LIQUID MAGMA REACHES
THE SURFACE, WHETHER IN A
SLITHERING FLOW OR A BOOMING
ERUPTION, WE CALL IT LAVA.
THOUGH MOLTEN LAVA MAY SEEM
THREATENING, IT'S NOT KNOWN TO
MOVE QUICKLY.
A VOLCANO'S PYROCLASTIC FLOW IS
FAR MORE DEADLY.
THIS POISONOUS ASH CLOUD CAN
RACE DOWN THE SLOPE OF A VOLCANO
LIKE A BULLET TRAIN,
OBLITERATING EVERYTHING IN ITS
PATH AT SPEEDS TOPPING 100 MILES
PER HOUR!
IT'S WHAT STOPPED THE RESIDENTS
OF POMPEII DEAD IN THEIR TRACKS.
BUT DESPITE THE VOLCANO'S BRUTAL
DESTRUCTION, IT IS ALSO A FORCE
OF BEAUTY AND REBIRTH FOR THE
PLANET.
LAVA CREATES NEW LANDS WHERE
LIFE CAN FLOURISH, LIKE IT OR
NOT, VOLCANOES ARE PART OF THE
PLANET'S LIFE CYCLE.
AS THE EARTH CONTINUES TO
EXPLODE, GURGLE AND SLITHER ITS
MOLTEN HEART OUT, WE MUST LEARN
TO LIVE SIDE BY SIDE WITH ITS
AWESOME POWER.
HEATHER: AND BEFORE WE GO ANY
FURTHER, SHE DID MENTION THAT
HAWAII WAS FORMED BY A HOT SPOT.
WHAT A HOT SPOT IS, IT'S A
LOCATION WHERE NOBODY KNOWS WHY,
BUT MAGMA CRACKS THROUGH THE
CRUST.
IT'S JUST A SPOT ON THE CRUST
WHERE IT'S A LITTLE THINNER AND
FOR SOME REASON IT'S ABLE TO
COME THROUGH.
AND SO WHAT HAPPENS IS THE HOT
SPOT REMAINS STATIC.
IT STAYS IN ONE PLACE WHERE THE
MAGMA IS COMING UP.
AND THE CONTINENT, OR THE PLATE,
OCEANIC PLATE AS WELL, IT WILL
MOVE OVER IT, AND AS IT MOVES
OVER IT, IT WILL CREATE ONE
ISLAND AFTER THE OTHER.
SO THAT'S HOW HAWAII WAS FORMED.
AND IF YOU LOOK AT THE LOCATION
AND MEASURE THE LOCATION OF LIKE
THE FIRST ISLAND AND THE LAST
ISLAND, YOU CAN CALCULATE HOW
FAST THE PLATE WAS MOVING BASED
ON THE AGES AND ALSO WHICH
DIRECTIONS THE PLATE WAS MOVING.
OKAY.
MAGMA VS. LAVA.
YOU'VE PROBABLY HEARD BOTH TERMS
USED IN REFERENCE TO VOLCANOES.
AND ALTHOUGH SOME PEOPLE THINK
IT'S THE SAME THING, IT'S
ACTUALLY NOT.
THE TERMS, THE ONLY DIFFERENCE
BETWEEN THE TERMS IS LOCATION.
SO THEY'RE REFERRING TO THE
LOCATION OF WHERE THE MELT IS.
MAGMA IS BELOW THE SURFACE.
AND SINCE IT'S BELOW THE
SURFACE, IT'S GENERALLY HOTTER
THAN LAVA BECAUSE IT'S NEAR THE
HEAT SOURCE.
LAVA IS ABOVE THE SURFACE.
SO IT'S A LITTLE BIT COOLER.
BUT THE SAME MELT, IF IT'S -- IF
IT'S AN ACTIVE VOLCANO, IT
SHOULD HAVE BOTH MAGMA AND LAVA.
AND, AGAIN, IT'S THE SAME MELT,
IT'S JUST YOU USE WHICH
DETERMINE DEPENDING ON WHERE
THAT MELT IS, WHETHER IT'S BELOW
THE SURFACE OR ABOVE THE
SURFACE.
IF MAGMA COOLS AND BECOMES ROCK
BEFORE -- BEFORE IT BECOMES
LAVA, WE REFER TO THOSE ROCKS
AS INTRUSIVE ROCKS.
THEY WERE FORMED INSIDE.
INTRUSIVE ROCKS HAVE MUCH LARGER
MINERAL CRYSTALS IN THEM BECAUSE
THEY TOOK SO LONG TO COOL.
SO THE CRYSTALS HAD A LONG TIME
TO GROW.
ROCKS FROM LAVA ARE JUST THE
OPPOSITE.
THEY'RE ABOVE THE SURFACE,
THEY'RE AWAY FROM THEIR HEAT
SOURCE, SO THEY COOL AND LITHIFY
INTO ROCKS VERY QUICKLY.
SO THE CRYSTALS DON'T HAVE MUCH
TIME TO COOL.
SO THAT'S AN INTERESTING WAY
THAT WHEN WE'RE EXAMINING ROCKS
WE CAN TELL IF IT CRYSTALLIZED
OUT OF A MAGMA OR A LAVA.
SO TYPES OF VOLCANOES.
IN THAT VIDEO WE SAW, SHE SPOKE
OF TWO KINDS, THE COMPOSITE AND
THE SHIELD VOLCANO.
GENERALLY, SCIENCE CONSIDERS
THERE TO BE THREE VOLCANOES, BUT
IT DEPENDS WHO YOU'RE TALKING
TO.
SOME INSIST THAT THERE'S FIVE
TYPES OF VOLCANOES.
SOME WILL SAY SIX AND SOME WILL
SAY SEVEN.
AND THE OTHERS ARE NOT
NECESSARILY VOLCANOES IN THE
SENSE OF WHEN WE THINK OF A
VOLCANO, YOU KNOW, WHEN WE'RE
THINKING HAWAII OR MT.
ST. HELENS.
THEY'RE JUST DIFFERENT FORMS AND
DIFFERENT WAYS THAT THAT MAGMA
IS COMING UP TO THE EARTH'S
SURFACE.
SO I'M GOING TO COVER FIVE OF
THEM, AND THESE ARE THE TYPES
THAT YOU GENERALLY THINK OF WHEN
YOU THINK VOLCANO.
SO THE FIRST IS SHIELD VOLCANOS.
PROBABLY ONE OF THE MOST COMMON,
AND WHEN WE THINK OF A VOLCANO.
I MEAN WE ALL THINK HAWAII,
RIGHT?
AND THESE VOLCANOES, THEY'RE
CALLED SHIELD VOLCANOES AFTER
ROMAN SHIELDS.
SO THEY'RE ROUND, THEY DON'T
HAVE A LOT OF RELIEF.
THEY'RE NOT VERY TALL.
THEY HAVE VERY GENTLE SLOPES
BETWEEN 2 AND 10 FEET, AND IN
HAWAII THEY ONLY RIDES ABOUT SO
KILOMETERS FROM THE SEAFLOOR.
SO THEY'RE NOT VERY TALL IN
TERMS OF MOUNTAINS OR OTHER
VOLCANOES, THEY'RE VERY, VERY
SHORT.
THEY HAVE BASALTIC LAVA.
SO IT'S VERY SIMILAR TO WHAT YOU
SAW COMING UP AT THE SPREADING
CENTERS.
SO BASALTIC AGAIN, IT'S VERY
HEAVY, IT'S VERY DARK, A LOT OF
MASS THESE YUM -- MAGNESIUM AND
IRON AND IT HAS A PRETTY LOW
VISCOSITY.
SO IT'S FLUID, BUT IT'S NOT LIKE
WATER.
SO WATER WOULD BE HIGH
VISCOSITY, TOOTHPASTE WOULD BE
LOW VISCOSITY.
AND EVEN THOUGH YOU MIGHT
SQUIRT, IF YOU SQUIRTED
TOOTHPASTE OUT HERE AND YOU LOOK
AT IT, IT WOULDN'T LOOK LIKE
IT'S MOVING AT ALL.
IT WOULDN'T LOOK LIKE IT'S
FLOWING.
BUT LEAVE FOR A DAY AND COME
BACK AND YOU'D FIND THAT IT
SPREAD OUT AND IT FLATTENED.
SO EVEN THOUGH IT'S HIGHLY
VISCOUS, IT STILL HAS SOME
FLUIDITY TO IT, IT CAN STILL
MOVE.
SO THAT'S WHAT BASALTIC LAVA IS
LIKE, IT'S VERY THICK.
IN HAWAII THEY ACTUALLY REFER TO
IT, THEY CALL IT ROPY TEXTURE OR
PA HOW HOW.
 -- PAHOEHOE.
IT'S JUST THESE BIG BLOBS AND
THEY'RE THICK AND THEY KIND OF
TWIST AND ROLL.
AND IN THE PICTURES -- THE
PICTURES ARE OF HAWAII, SO YOU
CAN SEE WHAT THEY LOOK LIKE WHEN
THEY ERUPT AND WHEN IT'S NOT
ERUPTING.
OKAY.
SO THEN THERE'S CINDER CONES.
THEY'RE ALSO CALLED PYROCLASTIC
CONES.
THESE ARE FORMED OF JUST
PYROCLASTS, WHICH ARE LOOSE
FRAGMENTS, ROCKS, MINERALS, ASH
THAT GETS EXPLODED OUT OF THE
VOLCANO.
SO THEY'RE VERY VIOLENT.
BUT IT'S LIKE LOOSE DEBRIS.
SO IT BUILDS UP, BUT THEY'RE
USUALLY ABOUT A SLOPE OF
30 DEGREES.
BECAUSE IT'S LOOSE, IT REALLY,
IT CAN'T BUILD A SLOPE ANY
HIGHER THAN 33 DEGREES SINCE
THERE'S GRAVITY.
IF IT GETS ANY STEEPER THAN,
THAT GRAVITY JUST PULLS IT DOWN.
ALTHOUGH THEY'RE TALL, FEW REACH
OVER 500 METERS HIGH, AND WHAT'S
INTERESTING IS THESE ARE VERY
SMALL THAN THEY'RE COMMON, AND
THEY CAN FORM ON THE THANKS OF
OTHER -- FLANKS OF OTHER
VOLCANOES.
BUT AGAIN, THEY DON'T HAVE A
VERY LONG LIFE SPAN BECAUSE IT'S
MOSTLY LOOSE DEBRIS.
SO WITH WEATHERING, YOU KNOW,
THEY JUST KIND OF CRUMBLE AND
FALL APART.
SO THEY DON'T LAST A WHOLE LONG
TIME.
COMPOSITE VOLCANOES, WHICH ARE
ALSO CALLED STRATOVOLCANOS, ARE
A COMPOSITE OF THE PREVIOUS TWO.
SO YOU HAVE LAYERS THAT
ALTERNATE AND YOU'LL HAVE
EXPLOSIONS, ERUPTIONS THAT
ALTERNATE.
SO IT WILL HAVE A TRUE LAVA FLOW
AND THEN IT WILL HAVE LIKE A
PYROCLASTIC FLOW, OR IT'S
EXPLOSIVE.
AND THESE LAYERS GO ON TOP OF
EACH OTHER.
NOW, THAT LOOSE DEBRIS, IT
DOESN'T FALL OFF OF THESE LIKE
IT DOES ON THE CINDER CONE.
AND THE REASON WHY IS BECAUSE
THE NEXT ERUPTION IS USUALLY A
LAVA FLOW AND IT WILL GO OVER
THE TOP OF IT, AND IT HOLDS IT
DOWN AND IT SOLIDIFIES IT AND IT
HOLDS IT ALL TOGETHER.
SO AS A RESULT, THESE VOLCANOES
GET VERY, VERY LARGE AND THEY
CAN BE VERY STEEP.
THEY CAN RISE TO OVER
5,000 METERS HIGH AND THEY CAN
BE 6 TO 12 MILES ACROSS AT THE
BASE.
THESE TAKE A VERY LONG TIME TO
BUILD.
AND ALMOST ALL THE FAMOUS
VOLCANIC ERUPTIONS THROUGHOUT
HISTORY THAT YOU THINK OF, YOU
KNOW, MT. ETNA, MT. VESUVIUS,
MT. ST. HELENS, THESE ARE ALL
STRATOVOLCANOES.
AND THEY'RE NOT NECESSARILY EVEN
IN COMPOSITION.
SO JUST BECAUSE IT'S A
STRATOVOLCANO DOESN'T MEAN THAT
IT'S GOING TO BE HALF LAVA
FLOWS, HALF PYROCLASTIC FLOWS.
EACH VOLCANO IS UNIQUE, AND THEY
WILL HAVE DIFFERENT PERCENTAGES
OF ERUPTIONS.
SO MT. RANIER IS 90% LAVA FLOWS
AND 10% PYROCLASTICS.
AND MT. ST. HELENS IS ACTUALLY
THE EXACT OPPOSITE OF THAT.
SO WHAT MAKES THE DIFFERENCE N
AND DETERMINES THOSE TYPES OF
FLOWS, A MAIN CULPRIT IS THE
GAS, WHICH TYPE OF GAS IS BEING
DISSOLVED AND HOW MUCH OF IT AND
HOW EASILY IT CAN ESCAPE.
NOW WE'LL MOVE ON TO A CALDERA,
WHICH IS ALSO CALLED A CRATER
LAKE.
AND THIS IS AN IMAGE FROM CRATER
LAKE IN OREGON.
SO WHEN YOU HAVE A FAIRLY LARGE
VOLCANO, AND IT EMPTIES OUT THE
MAGMA CHAMBER FAIRLY QUICKLY IN
EITHER A LARGE EXPLOSION OR A
SERIES OF LARGE EXPLOSIONS AND
ERUPTIONS, YOU NOW HAVE THIS
VOID IN THE VOLCANO AND YOU HAVE
ALL THIS WEIGHT UP ON TOP OF IT.
SO YOU HAVE A STRUCTURAL
PROBLEM.
AND IT CAN'T SUPPORT ITSELF.
SO IT EVENTUALLY CRASHES IN ON
ITSELF.
AND THEN YOU GET THIS HOLLOW,
AND IT WILL FILL WITH -- OVER
YEARS IT WILL FILL WITH
RAINWATER OR EVEN GLACIAL WATER,
DEPENDING ON WHERE IT'S AT, AND
SO YOU HAVE THIS LAKE IN THE
DEPRESSION.
NOW, IF THE VOLCANO HAS GONE
EXTINCT, MEANING THERE'S NO MORE
MAGMA, IT'S NEVER GOING TO
ERUPT, IT'S NEAR PROBABLY A
SUBDUCTION ZONE THAT DOESN'T
EXIST ANYMORE, THEN IT'S JUST
GOING TO REMAIN A LAKE AND, YOU
KNOW, NOTHING IS EVER GOING TO
ERUPT AGAIN.
BUT A LOT OF THESE FORM ON
VOLCANOS THAT ARE STILL ACTIVE.
SO WHEN THAT HAPPENS, THE
ERUPTION OCCURS UNDERNEATH IT
AND IT'S -- THE WATER, THE WATER
ACTUALLY MIXES WITH WHAT'S BEING
ERUPTED AND IT MAKES IT VERY
FLUID AND IT ALLOWS IT TO MOVE
FASTER AND MORE VIOLENTLY.
NOW, A LAVA DOME, THESE ARE KIND
OF CUTE.
THEY'RE -- THEY'RE VERY BULBOUS,
THEY'RE VERY ROUND.
THEY LOOK LIKE IF YOU TOOK LIKE
A BASKETBALL AND CUT IT IN HALF
AND SET IT ON THE GROUND, IT'S
JUST THIS ROUND THING.
SO IT'S NOT CLASSIC VOLCANO
SHAPE.
AND WHAT HAPPENS IS IN THE
ERUPTION, THE LAVA IS VERY, VERY
THICK.
IT'S SO THICK THAT IT CAN'T
REALLY FLOW.
SO IT JUST KIND OF PUSHES OUT
AND STICKS, AND THEN SOME MORE
COMES OUT.
AND AS IT COOLS AND BECOMES
ROCK, MORE IS PUSHING UP
UNDERNEATH IT, STARTS TO CRACK
AND CRUMBLE AND SORT OF ROLL
DOWN AND THEN IT MAKES WAY FOR
MORE.
SO IT FORMS THIS VERY ROUND
SHAPE.
THESE CAN FORM IN THE CRATER OF
COMPOSITE CONES.
SO A LOT OF THESE SMALLER
VOLCANIC FEATURES CAN FORM
WITHIN A LARGER VOLCANO ON THE
FLANKS OR ON THE SIDES.
IN THE MAGMA CHAMBER, WE HAVE A
VENT, A MAIN VENT THAT USUALLY
COMES STRAIGHT UP.
BUT PENDING ON THE VOLCANO, THEY
CAN HAVE VENTS COMING OFF ON ALL
THE SIDESSING, AND THESE CAN
FORM SMALLER VOLCANOES ON TOP OF
THE LARGE VOLCANO.
AND ABOUT 6% OF ERUPTIONS
ACTUALLY FORM THESE LAVA DOMES.
AND THE PICTURE OF THIS ONE IS
FROM AN ERUPTION IN CHILE OF A
LAVA DOME IN 2008 TO 2010.
SO TYPES OF ERUPTIONS.
SO THERE'S TWO DIFFERENT TYPES.
THERE'S THE HAWAIIAN TYPE, VERY
SLOW, DOESN'T SEEM TOO DANGEROUS
IF YOU STAY AWAY FROM IT.
AND THEN THERE'S THE TYPE LIKE
MT. ST. HELENS IN 1980.
VERY VIOLENT, A LOT OF GAS, A
LOT OF ASH.
SO THOSE TWO DIFFERENT TYPES ARE
EFFUSIVE AND EXPLOSIVE.
EFFUSIVE ARE OUR SHIELD
VOLCANOES.
SO IT'S JUST A GENTLE
OUTPOURING, THE BASALTIC LAVA,
IT DOESN'T HAVE MUCH SILICA IN
IT.
IT DOESN'T HAVE A LOT OF GAS IN
IT.
BUT WHAT THERE IS CAN COME OUT
EASILY.
SO IT'S VERY LIQUID, THE GAS CAN
JUST COME ON OUT.
IT DOESN'T CAUSE A LOT OF
EXPLOSIONS.
AND IT'S VERY HOT.
IT'S ABOUT 1200 DEGREES CELSIUS.
SO ALTHOUGH IT DOESN'T SEEM THAT
DANGEROUS, IF YOU GET IN ITS
WAY, IT'S OBVIOUSLY GOING TO
MELT, BURN, AND COVER ANYTHING
IN ITS PATH.
AND HERE'S A LITTLE VIDEO.
THIS IS JUST GOING TO SHOW YOU
IN HAWAII AN ERUPTION, AN
EFFUSIVE ERUPTION.
HEATHER: AND THIS IS THE SAME
TYPE OF LAVA THAT'S CREATING
MORE OCEAN CRUST.
ALTHOUGH YOU WOULDN'T WANT TO
GET CLOSE TO IT, IT'S ACTUALLY
AN ERUPTION THAT'S KIND OF
SOOTHING WHEN YOU WATCH IT.
IT'S NOT -- IT'S NOT VIOLENT.
THE OPPOSITE OF THAT IS THE
EXPLOSIVE ERUPTION.
SO COMPOSITE VOLCANOES, CINDER
CONES, AND LAVA DOMES ERUPT
EXPLOSIVELY.
SO IT'S A COOLER MAGMA, IT'S
MUCH MORE VISCOUS, IT'S MUCH
THICKER, MUCH MORE DENSE.
OH.
AND DISSOLVED GASES CAN'T ESCAPE
THIS TYPE OF MAGMA VERY EASILY.
SO WHAT HAPPENS IS THE PRESSURE
FROM THAT GAS JUST BUILDS AND
BUILDS AND BUILDS UNTIL IT
FINALLY HAS TO COME OUT.
AND WHEN IT DOES, YOU HAVE AN
EXPLOSIVE ERUPTION.
WHEN THAT HAPPENS, IT BLASTS
THIS ROCK AND THE MINERALS AND
LAVA INTO THE AIR AND A LOT OF
ASH, SO YOU'LL HAVE ANYTHING
FROM LARGE, LARGE COBBLE AND
BOULDERSIDE SIZE DOWN TO LIKE
POWDERY ASH.
AND IT BLASTS IT INTO THE AIR.
SO BEFORE WE TAKE OUR BREAK,
LET'S WATCH THIS SHORT LITTLE
VIDEO AND WE'LL SEE AN EXPLOSIVE
VOLCANIC ERUPTION IN JAPAN.
[ EXPLOSION ]
>> Heather: OKAY, NOW WE'LL
TAKE OUR LITTLE BREAK SINCE
WE'RE ABOUT HALFWAY THROUGH.
>> Heather: OKAY.
SO NOW LET'S MOVE ON TO VOLCANIC
GASES.
THE GASES THAT ARE BELCHING OUT
OF THESE VOLCANOES.
SO ROUGHLY -- EACH VOLCANO IS
UNIQUE, BUT ROUGHLY IT'S MOSTLY
WATER VAPOR AT ABOUT 78%, BUT
12% CARBON DIOXIDE, 7% SULFUR
DIOXIDE, AND THEN 3% OTHER
GASES.
NOW, WHERE THE PROBLEMS COME IN
IS WITH THE SULFUR DIOXIDE THAT
IT SPEWS INTO THE ATMOSPHERE.
IT -- WHEN IT MIXES WITH
RAINWATER, IT BECOMES SULFUR I
ACID -- SULFURIC ACID.
SULFURIC ACID, IT'S HIGHLY
REACTIVE, IT CHEMICALLY WEATHERS
THINGS VERY QUICKLY.
SO IT DISSOLVES THINGS.
THERE'S BEEN EXAMPLES OF PEOPLE
LIVING NEAR VOLCANIC REGIONS
WHERE THE HINGES ON THEIR DOORS
JUST GET MELTED OFF.
SO DEPENDING ON HOW MUCH HAS
BEEN SPEWED OUT, IT COULD BECOME
A REAL -- A REAL WEATHERING
PROBLEM.
SO THIS IS A LITTLE SNIPPET OF
THE PAPANDAYAN VOLCANO IN
INDONESIA, WHICH AGAIN IS A
STRATOVOLCANO.
AND YOU CAN SEE THEM GO UP AND
THEY'RE GOING TO LOOK AT THE
GAS.
AND YOU CAN SEE THAT IT'S VERY
YELLOW.
THAT'S THAT SULFUR DIOXIDE.
>> THIS IS STEEP HERE, ISN'T IT?
IT'S NOT JUST STEEP.
>> SUPER BLOODY MAXIMUM STEEP.
>> YOU SEE, DONNIE LEARNED
MOST-HIS EDGE -- MOST OF HIS
ENGLISH FROM EDDIE MURPHY
MOVIES.
>> WOW!
>> DONNY LEADS ME TO THE GAS
BEDS.
FANTASTIC DISPLAY OF THE POWER
THAT'S JUST BELOW OUR FEET.
>> NOW THAT SOUNDS LIKE A ROCKET
ENGINE!
[ MUSIC ]
>> HERE AT PAPANDAYAN, POWERFUL
VOLCANIC STEAM BLASTS THE SULFUR
TO THE SURFACE.
CREATING THIS EXQUISITE DISPLAY
OF COLOR.
NOW I WANT TO GET RIGHT UP IN
THE GAS FIELD.
>> LET'S GO TAKE A LOOK!
THAT'S SO AMAZING.
THERE'S SO MUCH LIQUID SULFUR IN
THAT ONE SPOT.
IT'S JUST BUBBLING AWAY.
INSIDE THESE VENTS IS A POND OF
LIQUID SULFUR, AND IN ITS LIQUID
FORM IT'S ORANGE.
WHEN IT COMES UP THROUGH THE
GAS, IT CRYSTALLIZES AND FORMS
THESE YELLOW DEPOSITS THAT YOU
SEE EVERYWHERE HERE.
BUT THE GAS IS SO -- COUGHS ]
TOXIC.
ONE OF THE EDGES COLLAPSED.
I PUT MY FOOT ON IT AND IT
SHOWERED ME WITH SULFUR
CRYSTALS.
AND IT BLEW RIGHT UP INTO MY
FACE.
OH WOW.
[ LAUGHS ]
IT'S A GOOD THING I WAS WEARING
THESE.
>> Heather: YEAH.
HE PROBABLY SHOULD HAVE BEEN
WEARING GOGGLES GOING INTO AN
AREA LIKE THAT.
[ LAUGHS ]
OKAY.
NOW, IT'S NOT WIDELY KNOWN, BUT
VOLCANOES HAVE THEIR OWN INDEX.
IT'S THE VOLCANIC EXPLOSIVITY
INDEX.
AND IT'S JUST LIKE THE RICHTER
SCALE FOR EARTHQUAKES.
SO IT'S A SCALE OF 0 TO 8, AND
IT TAKES INTO CONSIDERATION MANY
FACTORS OF A VOLCANO.
SO THE VOLUME OF THE ERUPTION,
SO HOW MUCH MAGMA AND
PYROCLASTICS HAVE ACTUALLY COME
OUT, THE HEIGHT OF THE ERUPTION
COLUMN, SO HOW HIGH UP IS IT
SHOOTING THE MAGMA AND
PYROCLASTICS?
SO THAT WOULD BE HOW MUCH POWER
THERE IS.
AND THEN HOW LONG THE ERUPTION
LASTS.
SO ERUPTIONS CAN LAST ANYWHERE
FROM A VERY SHORT TIME MEASURED
IN MINUTES AND HOURS TO ALL THE
WAY UP TO YEARS AND YEARS.
SO IT'S A LOGARITHMIC SCALE AND
THAT'S THE SAME AS THE RICHTER
SCALE.
SO WHEN YOU GO FROM LIKE 2 TO 3,
A 3 WOULD BE 10 TIMES MORE
INTENSE THAN A 2.
AND THE SAME FOR IF YOU GO FROM
A 3 TO A 4, IT WOULD BE ANOTHER
TEN-FOLD INCREASE.
SO THIS IS JUST AN EXAMPLE OF
THE INDEX.
YOU CAN FIND IT ONLINE QUITE
EASILY.
AND IT JUST DESCRIBES HOW MUCH
VOLUME AND WHAT TYPE OF AN
ERUPTION AND HOW BIG THE PLUME
IS AND HOW LONG IT ERUPTED FOR.
AND THEN IT GIVES YOU A FEW
EXAMPLES OF SOME HISTORICAL
ERUPTIONS.
OKAY, SO NOW WE'RE GOING TO GO
ON TO LIVING WITH VOLCANOES, HOW
VOLCANOES AFFECT US.
SO ENERGY AND CLIMATE.
THE HEAT FROM THE VOLCANOES CAN
ACTUALLY BE HARNESSED
AS GEOTHERMAL ENERGY.
SO IT'S POSSIBLY AN ALTERNATIVE
ENERGY SOURCE.
WHAT THEY DO IS THEY DRILL DOWN
SO THAT THEY CAN TRAP AND
COLLECT THE STEAM, AND THEN THEY
PIPE IT TO AN AREA THAT HAS
TURBINES.
THE STEAM TURNS THESE TURBINES
AND PRODUCES ELECTRICITY.
THE UNITED STATES IS ONE OF THE
LEADERS IN GEOTHERMAL ENERGY.
THERE'S MORE LOCATIONS WHERE
WE'RE DOING THAT THAN OTHER
NATIONS.
BUT IT IS -- IT IS SOMETHING
THAT'S STILL BEING LOOKED AT
AS A MAJOR POSSIBILITY.
I MEAN YOU HAVE THIS HEAT YOU
CAN HARNESS IT, YOU KNOW, MAYBE
IT'S WORTH A SHOT.
BUT ALL FORMS OF ENERGY
PRODUCTION, WHETHER ALTERNATIVE
OR NOT, THEY ALL HAVE THEIR PROS
AND THEIR CONS, AND ANYTIME YOU
GO DRILLING DOWN INTO SOMETHING
AND AFFECTING NATURE, THERE'S
ALWAYS REPERCUSSIONS OF SOME
KIND.
SO IT'S STILL FAIRLY NEW.
AND THEN OF COURSE THERE'S DUST
AND GAS FROM THE ERUPTIONS THAT
CAN REMAIN IN THE ATMOSPHERE FOR
YEARS, AND THEY CAN ACTUALLY
AFFECT THE ENTIRE PLANET
WORLDWIDE DEPENDING ON HOW GREAT
THE ERUPTION WAS, HOW LONG IT
LASTED, AND WIND PATTERNS.
SO, FOR EXAMPLE, IN 1991 IN THE
PHILIPPINES, MT. PINATUBO
ERUPTED, AND THE ASH THAT IT PUT
INTO THE ATMOSPHERE TRAVELED THE
ENTIRE WORLD.
AND IT CREATED THESE GORGEOUS
SUNSETS EVERYWHERE FOR A WHILE.
WHICH IS GREAT.
IT WAS PRETTY.
BUT THAT ASH ALSO, IT BLOCKED
SOLAR ENERGY.
SO IT BLOCKS THE SUN'S RAYS FROM
COMING IN, AND IT MIGHT BE SUCH
A SMALL AMOUNT THAT WE DON'T
EVEN REALLY NOTICE IT WITH OUR
EYES, BUT IT'S ENOUGH THAT IT
CAN LOWER OUR TEMPERATURE.
SO IT'S NICE BECAUSE IT COULD
COOL THE PLANET FOR A WHILE AND
MAYBE STAVE OFF RIEGZ
TEMPERATURES -- RISING
TEMPERATURES, BUT AT THE SAME
TIME YOU DON'T WANT SOMETHING SO
CATACLYSMIC THAT IT COOLS THE
PLANET FOR A LONG TIME.
AND MT. PINATUBO ACTUALLY
LOWERED THE WORLD AVERAGE
TEMPERATURE BY 1 DEGREE CELSIUS
FOR SEVERAL YEARS.
AND IN 1815, ANOTHER VOLCANO IN
INDONESIA ERUPTED, AND IT PUT SO
MUCH ASH INTO THE ATMOSPHERE
THAT THE YEAR 1816 AROUND THE
ENTIRE WORLD WAS KNOWN AS THE
YEAR WITHOUT A SUMMER.
IN NEW ENGLAND THEY ACTUALLY HAD
SNOW IN JUNE.
SO IF YOU DON'T LIKE HOT
WEATHER, THAT MIGHT SOUND GREAT.
BUT THE OTHER SIDE OF THAT IS,
WE NEED THOSE WARMER
TEMPERATURES, WE NEED THAT SOLAR
RADIATION, WE NEED THAT FOR
PRODUCING FOOD AND AGRICULTURE.
SO IT CAN REALLY LEAD TO FAMINE
AND POSSIBLY EVEN WORLDWIDE
FAMINE IF IT WAS ON A GREAT
ENOUGH SCALE.
SO DIFFERENT HAZARDS FROM
VOLCANOES.
SO LAVA FLOWS IS PROBABLY WHAT
WE MOST COMMONLY THINK OF, YOU
KNOW, THAT HOT LAVA, YOU KNOW,
IT BURNING AND BURYING
EVERYTHING IN ITS PATH.
OF COURSE IF YOU STAY OUT OF ITS
WAY, YOU'LL BE OKAY.
AND THEN THERE'S ASHFALLS.
SO PARTICLES FALLING ON YOU.
NOW, THESE CAN BE LARGE ENOUGH
THEY CAN HIT SOMEBODY IN THE
HEAD AND KNOCK THEM OUT.
THEY CAN BREAK THINGS.
THEY COULD BE FINE, SAND-LIKE
ASH.
BUT THAT CAN CAUSE ATMOSPHERIC
AND AIR QUALITY ISSUES.
IT CAN CLOSE AIRPORTS.
IT CAN CAUSE DAMAGE.
PYROCLASTIC FLOWS, THERE'S
EXPLOSIONS, YOU CAN GET BURIED
FROM THE DEBRIS.
LAHARS.
THAT'S WHEN THE VOLCANO MIXES
WITH RAINFALL OR IT CAN QUICKLY
IT MELT GLACIAL WATERS.
THESE WATERS MIX WITH THE LAVA,
MAKING THINGS MUCH MORE FLUID.
THEY CAN MOVE FASTER.
IT LUBRICATES THE LAVA, MAKING
THINGS MORE DANGEROUS.
AND ALTHOUGH WE USUALLY THINK OF
TSUNAMIS BEING CAUSED BY AN
EARTHQUAKE DEEP IN THE OCEAN,
THEY CAN ACTUALLY BE ASSOCIATED
WITH VOLCANOES AS WELL.
IF YOU HAVE A VOLCANIC ERUPTION
IN THE OCEAN BASIN DEEP IN THE
SEA AND IT'S GREAT ENOUGH THAT
IT DISPLACES A LOT OF WATER,
THAT WATER CAN RISE UP AND MOVE
WARDS LAND AS A TSUNAMI.
SO TSUNAMIS CAUSED BY VOLCANOES
ARE MUCH MORE RARE THAN CAUSED
BY EARTHQUAKES.
BUT IT IS A RISK WITH VOLCANOES.
AND THEN AS WE'VE SAID BEFORE,
WEATHER AND CLIMATE, YOU CAN
HAVE COOLER TEMPERATURES,
SHORTER GROWING SEASONS AND
POSSIBLY EVEN FAMINE.
AND THEN AIR QUALITY, POLLUTION,
THE SULFUR DIOXIDE THAT CAN
CHEMICALLY WEATHER THINGS.
SO THERE'S A LOT OF HAZARDS.
BUT IT ALSO CREATES NEW CRUST,
NEW LAND, YOU KNOW, FRESH
BEGINNINGS.
IT CAN ADD MINERAL CONTENTS AND
NUTRIENTS TO THE SOIL.
IT CAN MAKE THE SOIL RICHER.
I MEAN THINK OF HOW BEAUTIFUL
HAWAII IS WITH ALL THOSE RICH,
LUSH PLANTS.
THEY'RE FEEDING OFF ALL OF THAT
MINERAL CONTENT FROM THE
SOLIDIFIED LAVA.
SO THERE'S GOOD AND THERE'S BAD
WITH VOLCANOES.
SO NOW WE'LL GET ON TO THE
FUNNEST PART OF THE LECTURE, IN
MY OPINION, THE HISTORIC
VOLCANIC CATASTROPHES.
SO I'M GOING TO GO OVER -- WELL,
I'VE GOT A SHORT VIDEO FIRST
THAT'S GOING TO COVER THE FIVE
WORST VOLCANOES IN HISTORY.
AND THEN AFTER THAT, I'M GOING
TO COVER A FEW MORE.
SO WE'RE GOING TO LOOK AT WHAT
CAUSED THEM, WHEN THEY OCCURRED,
WHERE THEY OCCURRED, WHAT TYPE
OF VOLCANO.
OKAY, SO THESE ARE THE FIVE MOST
DEADLY ERUPTIONS THAT EVER
OCCURRED.
1902, MT. PELEE IN THE
CARIBBEAN.
IT WAS VERY QUICK.
IT WAS AN EXPLOSIVE ERUPTION.
AND IT KILLED EVERYONE ON THE
ENTIRE ISLAND.
IT JUST COVERED EVERYTHING.
AND THEN 1883 IN KRAKATOA,
INDONESIA.
1815 IN MT. TAMBORA, INDONESIA.
1600, AND I'M NOT EVEN GOING TO
TRY TO PRONOUNCE THAT ONE IN
PERU.
AND 1783 IN LAKI, ICELAND, WAS
THE ABSOLUTE WORST.
SO HERE'S THE LITTLE VIDEO
THAT'S GOING TO SHOW YOU A
LITTLE BIT MORE ABOUT EACH ONE.
[ MUSIC ]
>> Heather: OKAY.
SO HERE'S ONE THAT WE'VE ALL
HEARD OF BEFORE, MT. VESUVIUS.
AND IT ERUPTED IN THE YEAR 79.
SO IT'S IN ITALY.
IT WAS A 5 ON THE VOLCANIC
EXPLOSIVITY INDEX.
THAT'S PRETTY HIGH.
SO IT WAS A MAJOR EXPLOSION.
IT WAS A STRATOVOLCANO.
SO IT WOULD HAVE BEEN AN
EXPLOSIVE ERUPTION.
IT KILLED 3,000 PEOPLE
ESTIMATED, AND IT BASICALLY
COVERED THE CITIES OF POMPEII
AND HERCULANEUM COMPLETELY IN 5
TO 8 METERS OF HOT ASH.
AND WE'VE ALL SEEN THOSE TOURING
LIKE MUSEUM SHOWS FROM POMPEII
WHERE THEY HAVE THE PEOPLE THAT
WERE PRESERVED BASICALLY
SOLIDIFIED IN THE HOT ASH THAT
COVERED THEM.
SO IT WAS ALSO, IT'S STILL
ACTIVE.
AND SOME PEOPLE SAY THAT IT WAS
ERUPTING FROM 1631 ALL THE WAY
THROUGH 1944, AND IT REMAINS
SOMEWHAT ACTIVE.
BUT THE ACTUAL ERUPTIONS WERE
19 -- BIG ERUPTIONS WERE 1906,
1929, AND 1944.
NOW, THE SCARY PART IN THIS, AND
THE PART I DON'T UNDERSTAND, IS
IT'S ONE OF THE MOST DANGEROUS
VOLCANOES IN THE WORLD AND THE
CITY OF NAPLES SITS RIGHT AT THE
BASE OF MT. SHE SIEWFS AND --
VESUVIUS AND IT'S STILL ACTIVE.
SO IT'S VERY SCARY TO THINK WHAT
COULD HAPPEN.
I WOULDN'T WANT TO LIVE THERE.
I DON'T WANT TO LIVE NEAR A
VOLCANO.
BUT, YEAH.
SO IT'S THE -- IT'S ALSO THE
ONLY ACTIVE VOLCANO ON MAINLAND
EUROPE.
THERE'S ALSO MT. ETNA, BUT
THAT'S IN SICILY.
SO THIS IS A SHORT LITTLE VIDEO
ABOUT MT. VESUVIUS AND THE
ERUPTION IN 79.
>> MOUNT DE VESUVIUS ERUPTS IN
1879, DESTROYS THE CITY OF
POMPEII, ALL THE FARMLAND AROUND
IT, AND ALL THE PEOPLE IN IT.
AND WE HAVE IN THE EXHIBITION A
REAL PERSON FROM POMPEII WHO
DIED IN AD 79.
WE CALL HER THE RESIN LADY, BUT
IT'S VERY SOBERING WHEN YOU
THINK THAT THIS POOR WOMAN
ACTUALLY LIVED THE DAY OF THE
ERUPTION.
AND SHE WOULD HAVE BEENER THE
FIDE.
SHE RAN WITH 60 OR SO OTHER
PEOPLE INTO A BIG STORE ROOM AND
THERE THEY DIED.
>> Heather: OKAY.
NOW MT. KILAUEA IN HAWAII
ERUPTED IN 1959 AND IT WAS AN
EFFUSIVE ERUPTION.
SO VERY SLOW-MOVING, HEAVY,
THICK, BASALTIC LAVA.
SO IT WAS ONLY A 2 ON THE
VOLCANIC EXPLOSIVITY INDEX.
AND IT WAS VERY SHORT-LIVED.
IT DIDN'T LAST TOO LONG.
BUT THE AMAZING THING IS, IT
FORMED A LAKE OF LAVA AND WE'RE
LIKE WHAT, 61 YEARS LATER, IT IS
STILL COOLING.
IT WAS THAT HOT.
SO NOW WE'RE GOING TO SEE THAT
ONE EXPLODE.
SO THE GASES ARE CAUSING THE
LAVA TO COME UP INTO THE AIR
LIKE THAT.
BUT SINCE THIS LAVA IS, EVEN
THOUGH IT'S THICK, IT'S NOT
AS HARD AS THE PYROCLASTIC
FLOWS, THE GAS CAN EASILY COME
OUT OF IT, SO YOU DON'T HAVE
THOSE MASSIVE EXPLOSIONS LIKE
THE OTHERS.
[ MUSIC, DRUM BEATS ]
[ DRAMATIC MUSIC ]
>> Heather: AS THAT LAVA COOLS
AND SOLIDIFIES AND LITHIFIES,
IT'S CREATING MORE OF HAWAII, SO
IT'S GETTING BIGGER.
AND IT'S ALL COMING UP FROM ONE
HOT SPOT.
[ INSTRUMENTAL MUSIC ]
>> Heather: AND THE ERUPTION
OF MT. ST. HELENS IN 1980, IT
WAS VERY EXPLOSIVE, AND OF
COURSE THAT WAS IN WASHINGTON IN
THE U.S.
IT WAS A 4 TO A 5 ON THE
VOLCANIC EXPLOSIVITY INDEX, SO
DEFINITELY ONE OF THE MOST
EXPLOSIVE, AT LEAST IN MODERN
TIMES.
AND, AGAIN, IT'S ANOTHER
STRATOVOLCANO, HAVE VERY VIOLENT
WHEN IT ECK PROBABLIES AND IT
PRODUCED A MONUMENTAL BLAST THAT
WAS SO GREAT THAT WITHIN 10
SECONDS IT STRIPPED -- IT
STRIPPED AN AREA THAT WAS
10 KILOMETERS OF ALL THE SOIL
AND ALL THE VEGETATION.
IT JUST BLEW IT OUT.
AND UNFORTUNATELY THERE WERE 63
PEOPLE KILLED, INCLUDING A
GRADUATE STUDENT WHO WAS
STUDYING VOLCANISM AND HE WAS
TAKING MEASUREMENTS OF THE
VOLCANO.
SO EVEN THOUGH THEY EVACUATED,
BECAUSE THEY KNEW IT WAS GOING
TO EXPLODE, SO THEY EVACUATED,
BUT THEY JUST -- THERE WAS STILL
A FEW PEOPLE THERE THAT GOT
KILLED.
SO ITS DE MATED -- DECIMATED A
600 SQUARE KILOMETERS.
IT'S STILL ACTIVE RIGHT NOW, BUT
THERE'S NO SIGNS AND NO
INDICATIONS THAT IT'S GOING TO
ERUPT ANYTIME SOON.
SO MOST OF THESE ACTIVE
VOLCANOES, THEY'RE MONITORED AND
WATCHED.
BUT PREDICTIONS HAVE GOTTEN MUCH
BETTER IN RECENT TIMES THAN THEY
USED TO BE.
BUT THEY CAN'T SAY FOR 100 --
YOU KNOW, 100% SURE IT'S GOING
TO EXPLODE ON THIS DATE.
JUST DON'T KNOW.
SO IT'S STILL ACTIVE.
BUT BEFORE 1980, THE LAST TIME
IT ERUPTED WAS 1857.
SO IT DOESN'T -- IT'S NOT A
FREQUENT ERUPTER, BUT, YOU NEVER
KNOW.
AND IT WAS FORMED BY -- AND IT'S
KEPT ACT I BY THE SUBDUCTION OF
THE JUAN DEFUCA PLATE GOING
UNDERNEATH THE NORTH AMERICAN
PLATE AT WASHINGTON.
SO THE PLATE IS BEING SUBDUCTED
UNDER AND AS IT GETS DEEPER, IT
GETS HOTTER, SO IT'S STARTING TO
MELT THE JUAN DE FUCA PLATE AND
IT MELTS IT INTO MAGMA AND THEN
IT'S COMING UP INTO MT.
ST. HELENS.
AND HERE'S SOME FOOTAGE OF THE
ACTUAL 1980 ERUPTION OF MT.
ST. HELENS.
>> ALMOST 10,000 FEET TALL, MT.
ST. HELENS IS ONE OF SEVERAL
ACTIVE VOLCANOS IN WASHINGTON'S
CASCADES MOUNTAIN RANGE.
>> Heather: AND MT. PINATUBO
IN THE PHILIPPINES ERUPTED IN
1991.
IT WAS THE SECOND LARGEST
ERUPTION OF THE 20th CENTURY.
AND IT WAS A 5 TO 6 ON THE VEI.
SO IT WAS A VERY, VERY VIOLENT,
VERY POWER 68 E -- POWERFUL
ERUSSIAN.
AND AGAIN, WE HAVE ANOTHER
STRATOVOLCANO.
THEY EVACUATED, SO THEY ESTIMATE
THAT THEY SAVED ABOUT FOR
THOUSAND LIVES -- SAVED ABOUT
5,000 LIVES.
THIS PARTICULAR VOLCANO PUT
FORTH LARGE AMOUNTS OF SULFUR
DIOXIDE, POLLUTING THE
ATMOSPHERE, AND THE AIRLINES IN
THE AREA, THE ASH CAUSED THEM
$100 MILLION IN DAMAGE FROM THE
PLANES SUCKING IN THE ASH.
AND IT -- THE LAST TIME IT
ERUPTED WAS OVER 400 YEARS AGO.
SO IT DOESN'T ERUPT THAT OFTEN,
BUT IT'S VERY VIOLENT WHEN IT
DOES.
AND SO THIS IS A LITTLE NEWS
PIECE, A BRITISH NEWS PIECE
SHOWING THE DEVASTATION IN THE
AREA AFTERWARDS.
>> A DESOLATE EERIE LANDSCAPE IN
THE NORTHERN PHILIPPINES.
IT LOOKS LIKE THE
AFTERATMOSPHERE OF A NUCLEAR
HOLOCAUST.
INSTEAD IT'S THE ERUPT -- WRATH
OF MT. PINATUBO, KILLING MORE
THAN 300 PEOPLE, LEAVING
THOUSANDS MORE HOMELESS, CASTING
A SHADOW OVER THE FUTURE ROLE OF
THE U.S. ON THE ISLAND NATION.
THE ANGRY GIANT AWOKE ON
JUNE 9th AFTER A 611-YEAR
SLUMMER.
A MUSHROOM CLOUD OF STEAM, ASH
AND SMOKE ROSE 30 KILOMETERS
INTO THE SKY.
THOUSANDS OF ERUPTIONS ROCKED
THE REGION.
AS IT SETTLED, THE DEBRIS
BLOTTED OUT THE SUN AND COATED
HUNDREDS OF KILOMETERS OF
PHILIPPINE COUNTRYSIDE WITH WHAT
LOOKED LIKE SNOW.
MANY LOCALS STAYED IN THEIR
HOMES AROUND THE BASIN SLOPES OF
THE VOLCANO IN SPITE OF WARNINGS
TO LEAVE.
[ SCREAMS ]
OTHERS FLED FOR THEIR LIVES
AS PINATUBO REAWAKENED.
[ YELLING ]
FRIGHTENED AND HELPLESS,
VILLAGERS FLED TO NEARBY TOWNS
AND INTO THE CAPITAL, MANILA,
LEAVING THEY'RE HOMES TO THE
MERCY OF THE MOUNTAIN.
THEY LEFT HOWEVER THEY COULD,
TAKING WHAT LITTLE THEY COULD
CARRY.
THIS IS THE CITY OF A LONGER FOE
AT 9:00 IN THE MORNING.
IT'S 25 MILES FROM THE VOLCANO.
THE POWER HAS BEEN CUT, PEOPLE
CUE FOR FEW, LAMPS AND
GENERATORS.
IN THE SHADOW OF THE MOUNTAIN
IT'S RAINING MUD, WET ASH COVERS
EVERYTHING.
THE RIVERS ARE BROWN, FLOWING
UNDER RELICS OF A PREVIOUS
NATURAL DISASTER, THE EARTHQUAKE
A YEAR AGO.
UNDER THREAT FROM THE MUD FLOW
AND ASH CLOUD, HILLSIDE VILLAGES
ARE EVACUATED.
A NUMBER OF TRIBESMEN ARE
REPORTED BURIED UNDER THE
MUDSLIDES, OTHERS ARRIVE AT
EVACUATION CENTERS TO BE
REUNITED WITH LOST RELATIVES.
NATURE IS CONSPIRING ONCE MORE
AGAINST THE PEOPLE OF THIS
COUNTRY.
>> Heather: NOW MT. ETNA,
WHICH SITS ON SICILY.
IT ERUPTED CONTINUOUSLY FROM
1991 UNTIL 1993, AND THEN IT
STARTED ERUPTING AGAIN IN 2013
AND IT'S STILL ERUPTING TODAY.
SO IT'S ONLY A 1 TO 2 ON THE
VOLCANIC EXPLOSIVITY INDEX.
SO IT'S NOT ALL THAT VIOLENT.
BUT WHAT MAKES IT SO NOTEWORTHY
IS HOW LONG IT ERUPTS.
AND AGAIN, IT'S A STRATOVOLCANO.
IT'S VIOLENT, BUT IT'S NOT AS
VIOLENT AS THE OTHER ONES THAT
WE'VE SEEN.
IT'S CALMER.
BUT IT'S ONE OF THE WORLD'S MOST
ACACTIVE VPS AND -- ACTIVE
VOLCANOES AND IT ACTUALLY
ERUPTED FOR 473 DAYS STRAIGHT
ONE TIME AND THAT WAS BETWEEN
'91 AND '93.
AND WHEN IT DID SO, IT EXTRUDED
OVER 300 MILLION CUBIC METERS OF
LAVA.
SO THAT IS A LOT.
AND IT'S FORMED BETWEEN TWO
PLATES, THE AFRICAN PLATE IS
SUBDUCTING UNDERNEATH THE
EURASIAN PLATE NEAR SICILY.
AND SO THE AFRICAN PLATE IS
MELTING WHERE IT SUBDUCTS, AND
IT'S COMING UP AS MT. ETNA.
SO THIS IS A SHORT ABC NEWS
VIDEO SHOWING THE ACTUAL
ERUPTION IN '91 TO '93.
[ ERUPTION ]
[ EXPLOSION SOUNDS ]
>> Heather: AND YOU CAN SEE,
EVEN THOUGH IT'S EXPLODING, IT'S
NOT AS POWERFUL AS MT. PINATUBO
OR MT. ST. HELENS THAT WE JUST
SAW.
AND IT'S NOT FLOWING LIKE THE
SHIELD VOLCANOS OF HAWAII THAT
WE SAW.
IT'S MUCH THICKER, THE LAVA
THAT'S COMING OUT, IT'S VERY
THICK.
IT SOLIDIFIES QUICKER.
>> Heather: THIS PARTICULAR
SLIDE, IT GOT A LITTLE EXCITED
AND THOUGHT THAT IT WAS GOING TO
BE IN NEXT WEEK AND IT SAYS
EARTHQUAKES IN 2020.
SO JUST PRETEND THAT THAT SAYS
VOLCANOES.
SO A LOT OF PEOPLE ARE SHOCKED
TO FIND OUT THAT IN 2020 THERE
WERE 55 VOLCANIC ERUPTIONS
ALREADY.
I MEAN WE DON'T NECESSARILY SEE
IT EVERY DAY ON THE NEWS OR
THINK ABOUT IT.
BUT THERE'S VOLCANOES ERUPTING
EVERY DAY.
AND IN 2020 SO FAR, THERE'S BEEN
11 NEW ERUPTIONS.
SO THOSE WERE COMING OUT OF
VOLCANOES THAT HAVE NEVER
ERUPTED BEFORE OR NEW VOLCANOES
OR SOMETIMES EVEN VOLCANOES THAT
ARE THOUGHT TO BE EXTINCT CAN
RENEW IN THEIR VOLCANISM.
SO RIGHT NOW IN THE UNITED
STATES WE HAVE THREE VOLCANOES
ERUPTING RIGHT NOW TODAY, AND
THEY'RE ALL THREE IN ALASKA.
SO THESE AREN'T HUGE ERUPTIONS,
THEY'RE NOT ALL THAT EXCITING,
BUT THEY ARE ERUPTING RIGHT NOW.
AND SO I WANT TO SHOW YOU A
WEBSITE THAT YOU CAN GO ON AND
IT'S FROM THE SMITHSONIAN THEIR
STIEWG ON GLOBAL VOLCANISM, AND
YOU LOOK UP ANY VOLCANO IN THE
WORLD, YOU CAN LOOK UP WHAT'S
ERUPTING TODAY IN THE U.S., YOU
CAN LOOK UP WHAT WAS ERUPTING
THE YEAR YOU WERE BORN, YOU CAN
LOOK UP ALL KINDS OF DIFFERENT
FACTS ABOUT THESE VOLCANOES.
AND WHAT MAKES THIS WEBSITE SO
FANTASTIC AND FUN IS THAT YOU
CAN CLICK ON THE NAME OF THE
VOLCANO AND IT WILL TAKE YOU TO
GOOGLE EARTH AND IT SHOWS YOU
THE VOLCANO RIGHT NOW.
SO YOU CAN HAVE A LOOK AT IT.
AND IT ALSO GIVES YOU ALL KINDS
OF FACTS ABOUT IT.
SO HOPEFULLY THIS LINK WILL WORK
RIGHT NOW.
GOOD, LET'S HOPE.
IS IT GOING TO OPEN?
OKAY.
SO AT THE TOP, IT SAYS THIS IS
MT. ST. HELENS' 40th
ANNIVERSARY.
SO I WAS ON THE PAGE OF WHAT WAS
ERUPTING THIS YEAR, AND THIS IS
A LIST OF ALL THE VOLCANOES THAT
ARE ERUPTING.
AND IF IT SAYS CONTINUING, THAT
MEANS THAT IT'S STILL ERUPTING.
AND SO YOU CAN JUST CLICK ON THE
NAME AND THEN WHEN YOU GO DOWN
HERE, THERE'S A LIST OF
QUESTIONS.
AND IF YOU CLICK ON THEM, IT
WILL TAKE YOU TO THE INFORMATION
OR THE VOLCANOES THAT ANSWER THE
QUESTION.
SO LIKE LONGEST ERUPTIONS, HOW
MANY ACTIVE VOLCANOES ARE THERE
RIGHT NOW, IS VOLCANIC ACTIVITY
INCREASING, THINGS OF THAT SORT.
AND WHAT WAS ERUPTING IN THE
YEAR, SO YOU CAN ENTER ANY YEAR
AND SEE WHAT WAS ERUPTING.
SO LET'S HAVE A LOOK AT -- LET'S
HAVE A LOOK AT CLEVELAND
VOLCANO.
THIS IS ONE THAT'S ERUPTING
RIGHT NOW IN ALASKA.
SO AS YOU CAN SEE, IT'S NOT REAL
EXCITING RIGHT NOW.
BUT THAT IS IT.
AND IT IS ERUPTING.
AND IT WILL TELL YOU THE
VOLCANIC REGION, THE TYPE OF
VOLCANO, THE LAST KNOWN ERUPTION
DATE, WHERE IT'S LOCATED, HOW
TALL IT IS.
YOU CAN GO DOWN HERE AND YOU CAN
CLICK ON MORE INFORMATION ABOUT
THE VOLCANOES.
SO IF YOUR LOOKING UP VOLCANOES,
THIS IS THE BEST WEBSITE THERE
IS, SO YOU CAN HAVE SOME FUN
WITH THAT ONE.
OKAY, NOW WE'RE GOING TO GO ON
TO ERUPTION FORECASTING AND SOME
LOCAL CONCERNS FOR US ABOUT
VOLCANOES.
SO ERUPTION FORECASTING, IT
DIDN'T USED TO BE ALL THAT
GREAT.
RIGHT NOW THERE'S A HANDFUL OF
OBSERVETORIES AROUND THE WORLD.
OH, WHAT IS THAT?
JUST -- SO THERE'S A HANDFUL OF
OBSERVETORIES AROUND THE WORLD.
THEY MONITOR THE VOLCANIC
BEHAVIOR.
AND THEY DO SO BY MEASURING THE
SLOPE OF THE MOUNTAIN.
WHEN THE MAGMA STARTS TO BUILD
AND GET HOTTER, IT KIND OF
BULGES OUT A LITTLE, SO THE
SLOPE CHANGES.
SO THEY TAKE A LOT OF
MEASUREMENTS OF THE SLOPE.
EARTHQUAKE ACTIVITY, WHEN THINGS
START TO RUMBLE AND MOVE DOWN
THERE AND START TO SHAKE A
LITTLE BIT, THAT CAN BE A TIPOFF
THAT IT'S GETTING A LITTLE
UPSET, SOME GASES ARE MOVING
AROUND, YOU KNOW, IT'S GETTING
CLOSER TO ERUPTING.
THEY MEASURE THE GAS CONTENT
THAT'S COMING OUT OF THE
VOLCANO.
AND THEY CAN ALSO MEASURE THE
1WE8ING WITH SATELLITE --
SWELLING WITH SATELLITE AM
ANGRY -- IMAGERY.
AND SO FAR TO DATE, THE
SATELLITE IMAGERY HAS BEEN THE
BEST TOOL FOR PREDICTING THESE
AND THEY CAN DO PRETTY WELL WITH
THEM AND IN MOST CASES THEY CAN
EVACUATE BEFORE A CATASTROPHE
OCCURS.
BUT FORECASTING OF ANYTHING,
WHETHER IT BE WEATHER OR
EARTHQUAKES, VOLCANOES, IT'S NOT
PERFECT AND THEY'RE JUST
EDUCATED GUESSES BASED ON THE
TOOLS AND THE DATA THAT THEY
HAVE.
BUT THEY'RE DEFINITELY GETTING
BETTER AND MORE ACCURATE.
SO WE'RE IN KANSAS.
SO IT DOESN'T SEEM LIKE WE'D BE
AT ANY RISK OR HAVE VOLCANOES
AFFECT OUR LIFE IN ANY WAY.
BUT THEY ACTUALLY COULD IN SOME
OF THE WAYS WE'VE SEEN BEFORE,
ATMOSPHERE, AGRICULTURE, IN
THOSE WAYS.
BUT WHAT'S INTERESTING IS IN
1999, SOME RESEARCHERS FROM THE
KANSAS GEOLOGICAL SURVEY WERE
TAKING MEASUREMENTS AND DOING
RESEARCH IN RILEY AND MARSHALL
COUNTIES AND THEY DISCOVERED
THREE ANCIENT VOLCANIC FEATURES.
SO THEY'RE NOT ACTIVE BY ANY
MEANS.
THEY WERE EXTINCT MANY, MANY
MILLIONS OF YEARS AGO.
BUT THEY DISCOVERED THREE
KIMBERLITE PIPES.
KIMBERLITE PIPES ARE NAMED FOR
AN AREA IN AFRICA CALLED
KIMBERLY, WHICH IS WHERE A LOT
OF DIAMONDS ARE FOUND.
KIMBERLITE PIPES ARE BASICALLY A
PIPE WHERE MAGMA IS COMING UP.
SO THEY'RE A LITTLE DIFFERENT
THAN A TRADITIONAL VOLCANO, BUT
THEY ARE A VOLCANIC FEATURE.
AND THEY'RE USUALLY BRINGING
MAGMA FROM AN EXTREMELY DEEP
LOCATION, DEEPER THAN YOUR
AVERAGE VOLCANO.
AND THAT'S WHY THEY BRING UP A
LOT OF DIAMONDS, BECAUSE, YOU
KNOW, DIEMSD NEED THAT PRESSURE,
THEY'RE -- DIAMONDS NEED THAT
PRESSURE, THEY'RE FOUND VERY
DEEP.
AND SO THEY FOUND THREE OF THESE
PIPES.
UNFORTUNATELY, NO DIAMONDS.
SO ALL THE DIAMONDS FROM THE
KIMBERLITE PIPES ARE STILL IN
AFRICA, WE DIDN'T GET ANY.
BUT SO WE DID HAVE SOME VOLCANIC
ACTIVITY AT SOME POINT.
WE DON'T HAVE ANY RIGHT NOW.
BUT WE ARE CLOSE TO COLORADO,
AND COLORADO HAS SEVERAL ACTIVE
VOLCANOES RIGHT NOW, AND THEY
HAVE ONE, THE DOTSERO VOLCANIC
CENTER, IT'S ACTIVE, BUT THE
LAST TIME IT ERUPTED WAS 4,100
YEARS AGO, IT'S NOT BELIEVED
THAT IT COULD ERUPT ANYTIME
SOON.
BUT THINGS DO CHANGE.
THINGS HAPPEN.
THAT'S OUR CLOSEST VOLCANIC
RISK.
IT'S ABOUT A THREE-HOUR DRIVE
FROM DENVER.
SO... I'VE NEVER BEEN THERE, BUT
I HOPE TO AT SOME POINT.
SO THAT WRAPS UP THE LECTURE ON
VOLCANOES, AND NEXT WEEK WE'RE
GOING TO TALK ABOUT EARTHQUAKES.
AND THOUSAND WE'RE READY FOR
QUESTIONS.
 -- AND NOW WE'RE READY FOR
QUESTIONS.
OH.
YES?
[ OFF MIC ]
>> Heather: YEAH ACTUALLY
YELLOWSTONE WAS -- IT WAS A
VERY, VERY BIG CATASTROPHIC
VOLCANO, VOLCANIC EXPLOSION AT
THE TIME WHEN IT WAS CREATED.
IT HAS A LOT OF ACTIVITY GOING
ON.
I MEAN THE GEYSERS, THE HEAT
FROM IT, AND A LOT OF SCIENTISTS
DO BELIEVE THAT AT SOME POINT IT
COULD EXPLODE.
IT'S BEEN GETTING A LITTLE MORE
ACTIVE LATELY.
SO THAT IS A RISK.
I MEAN WE'RE NOT THAT FAR IN
TERMS OF VOLCANIC EXPLOSIONS,
WE'RE NOT THAT FAR AWAY.
SO THAT WOULD -- THAT WOULD
DEFINITELY BE A CATASTROPHE IF
THAT HAPPENED.
YES?
[ OFF MIC ]
OH SURE.
LET ME GO BACK TO IT.
YEAH.
IT'S VOLCANO.S I.EDU.
VOLCANO.SI.EDU.
I'M SORRY.
I DIDN'T HEAR THE QUESTION.
OH.
SHE ASKED WHERE ARE THE
VOLCANOES IN ALASKA.
WELL, THEY ARE IN DIFFERENT
LOCATIONS, BUT THEY'RE ALL IN
ONE, IN ONE MOUNTAIN BELT.
AND IT'S ANOTHER SUBDUCTION
ZONE.
SO IT'S INLAND FROM THE
SUBDUCTION ZONE.
AND IF YOU -- YEAH, IF YOU GO TO
THAT WEBSITE, IT WILL TELL YOU
LIKE EXACT LATITUDE AND
LONGITUDE WHERE EACH OF THEM
ARE.
DID WE HAVE ANY ONLINE
QUESTIONS, PAT?
OKAY.
ARE THERE ANY OTHER QUESTIONS?
OKAY, WELL, IN THAT CASE, I'D
LIKE TO THANK YOU ALL VERY MUCH.
AND NEXT WEEK WE'RE GOING TO DO
EARTHQUAKES.
AND I THINK YOU HAVE AN
ANNOUNCEMENT FOR THEM FOR
LOCATION.
- I JUST WANT TO REMIND
EVERYBODY THAT NEXT WEEK WE WILL
BE MEETING IN ROOM 180.
AND SO THAT'S ON THE OTHER SIDE
OF THE BUILDING AND YOU WILL
ENTER AT DOORS D OR N.
SO YOU'LL LOOK FOR THE D OR THE
N AND THAT'S WHERE YOU WILL
ENTER THE BUILDING.
THIS WEEK WE HAD TO MOVE YOU
BECAUSE WE HAVE -- THIS IS A
POLLING SITE TOMORROW.
AND SO ROOM 180 IS FULL OF
VOTING MACHINES RIGHT NOW.
AND PEOPLE GETTING READY FOR THE
ELECTION TOMORROW.
SO WE APPRECIATE YOU BEARING
WITH US TODAY AND BEING A PART
OF OUR VERY FIRST CLASS WHERE
WE'VE DONE HYBRID, WHERE WE'VE
BEEN STREAMING AND HAVING PEOPLE
HERE IN PERSON, AND WE LOOK
FORWARD TO SEEING YOU NEXT WEEK.
SO THANK YOU!
