Original subtitles

THE TRAGIC ANNIHILATION OF POMPEII IS LEGENDARY.

NOW, 2,000 YEARS LATER, BENEATH THE SAME ITALIAN COASTLINE,

A TICKING TIME BOMB IS BREWING

THAT COULD DWARF THE POMPEII ERUPTION.

IT'S GOING FASTER NOW!

THIS LONG-DORMANT SUPERVOLCANO

IS CONSIDERED THE MOST DANGEROUS IN THE WORLD...

HOLY MOLY.

...AND IT'S POISED TO SHROUD THE EARTH IN A VOLCANIC WINTER

THE LIKES OF WHICH WE'VE NEVER SEEN.

IF CAMPI FLEGREI EXPLODES,

IT COULD CHANGE THE COURSE OF HISTORY FOREVER.

WE'LL DEPLOY CUTTING EDGE TECH...

THAT'S INCREDIBLE, STEPHAN.

...IN A QUEST TO DETERMINE HOW MUCH TIME WE'VE GOT LEFT.

THIS IS LEAKING HEAT EVERYWHERE.

THIS IS SCARY.

BURIED DEEP BELOW THE EARTH'S SURFACE,

THERE ARE COUNTLESS UNSOLVED MYSTERIES.

AND, TODAY, WE FINALLY HAVE THE TOOLS TO UNLOCK THEM.

THAT'S AMAZING.

IT'S SUPER DEEP!

I'M ROB NELSON,

A SCIENTIST AND EXPLORER

INVESTIGATING OUR PLANET'S HIDDEN DEPTHS.

HUH, GETTING DEEPER.

HOLY MOLY, STEFAN!

... AND HELPING ME UNCOVER THESE SUBTERRANEAN SECRETS

IS TECH SPECIALIST, STEFAN BURNS.

OH, MY GOD. LOOK AT THAT!

TOGETHER...

I'VE GOT SOMETHING!

...WE ARE UNCOVERING NEW LEADS IN OUR QUEST TO SOLVE

EARTH'S MOST ENDURING MYSTERIES.

OH!THERE WE GO! WOO!

THESE ARE THE "SECRETS OF THE UNDERGROUND."

Captions by VITAC-- www.vitac.com

CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS

NAPLES, ITALY--

ONE OF THE MOST HEAVILY POPULATED AREAS IN EUROPE.

IT'S A CROWDED CITY THAT'S THE MOST DENSELY POPULATED IN ITALY,

AND A MAJOR TOURIST ATTRACTION FOR MILLIONS MORE,

INCLUDING ME AND STEPHAN.

WHY DID YOU RENT A CLOWN CAR?

I MEAN, TWO OF US IN HERE?

I FIGURED WE COULD USE SOMETHING TO LAUGH ABOUT

IN THE FACE OF IMPENDING DOOM

BECAUSE, AS BEAUTIFUL AS IT MAY BE,

NAPLES IS SITTING ON A SLEEPING MONSTER--

A HUGE VOLCANIC CALDERA, OR COLLAPSED CRATER,

THAT HAS GENERATED SOME OF THE DEADLIEST ERUPTIONS

IN HUMAN HISTORY.

OKAY, CHECK THAT OUT, VESUVIUS!

WOW.

79 A.D. THAT THING BLEW UP,

SENT CLOUDS OF ASH AND HOT CINDERS

21 MILES INTO THE SKY.

IT CHANGED THE COURSE OF HUMAN HISTORY...

OF COURSE. ...FOREVER.

IT RANKS UP THERE WITH ONE OF THE WORST HUMAN DISASTERS

OF ALL TIME.

THE ERUPTION THAT BURIED POMPEII MAY BE THE AREA'S MOST INFAMOUS,

BUT GEOLOGISTS FEAR THERE IS A FAR BIGGER VOLCANIC THREAT

LURKING BENEATH THE SURFACE HERE

THAT WILL DWARF ANYTHING WE'VE EVER SEEN IN THE HISTORY BOOKS.

AND HERE'S WHAT'S

THIS WHOLE REGION, FULL OF VOLCANOES,

BUT THE BIGGEST ONE OF ALL TIME IS CAMPI FLEGREI.

CAMPI FLEGREI, WHICH MEANS "BURNING FIELDS,"

IS AN 8-MILE-WIDE CALDERA

AND IS THE WORLD'S MOST DANGEROUS VOLCANO.

AND THIS LOOMING DISASTER ISN'T ONLY A THREAT TO ITALY.

IT COULD BE CATASTROPHIC FOR THE ENTIRE PLANET.

WHEN THIS SUPERVOLCANO ERUPTS, IT COULD COVER EUROPE

IN ASH INCHES DEEP,

PLUNGE THE WORLD INTO A VOLCANIC WINTER,

AND UNLEASH A CHAIN OF EVENTS THAT PUTS MILLIONS,

IF NOT BILLIONS, OF LIVES AT RISK.

SEVERE DROUGHT, GLOBAL FOOD SHORTAGES,

ECONOMIC MELTDOWN,

AND WIDESPREAD ANNIHILATION OF WILDLIFE--

WITH SO MUCH AT RISK FOR THE ENTIRE PLANET,

THE BURNING QUESTION IS NOT

IF BUT WHEN WILL THIS SUPERVOLCANO WILL BLOW?

THERE ARE ALARMING SIGNS THAT SUGGEST

WE'RE RUNNING OUT OF TIME.

SCIENTISTS RECENTLY FOUND EVIDENCE

OF INTENSE VOLCANIC ACTIVITY

IN THE HEART OF CAMPI FLEGREI.

THE THING IS, WITH THESE VOLCANOES,

YOU NEVER KNOW WHERE THEY'RE GOING TO GO.

BUT PEOPLE THINK CAMPI FLEGREI,

IT'S COMING BACK TO LIFE.

YEAH. AND IF IT EXPLODES,

IT COULD CHANGE THE COURSE OF HISTORY FOREVER.

SCIENTISTS ARE STILL UNSURE IF CAMPI FLEGREI

IS PART OF THE SAME VOLCANIC SYSTEM

AS ITS MORE FAMOUS NEIGHBOR TO THE EAST, MOUNT VESUVIUS.

BUT SOME THEORIZE THAT WHEN ONE VOLCANO IS QUIET,

THE OTHER BEGINS TO STIR.

THE MOST RECENT ERUPTION AT MOUNT VESUVIUS OCCURRED IN 1944,

A BLINK OF AN EYE IN GEOLOGIC TIME.

IT'S STILL CONSIDERED ACTIVE TODAY.

I CAN'T BELIEVE WE'RE HEADING TO THE TOP OF MOUNT VESUVIUS.

YOU LOOK OUT AND YOU CAN SEE MILLIONS OF PEOPLE DOWN THERE.

THIS IS COMPLETELY DEVELOPED.

THE ERUPTION IN 79 A.D. TOOK THE PROSPEROUS CITY OF POMPEII

BY SURPRISE.

MANY OF IT'S RESIDENTS HAD, IRONICALLY,

ATTENDED A FESTIVAL CELEBRATING THE GOD OF FIRE, VULCAN,

THE PREVIOUS DAY.

AT NOON ON THE 24th OF AUGUST, WHILE SLAVES PREPARED LUNCH

AND THE RESIDENTS OF POMPEII RELAXED IN BATHS AND LIBRARIES,

THEY SAW THE FIRST SIGN OF IMPENDING DOOM--

A CLOUD OF ASH IN THE DISTANCE.

BUT THINGS QUICKLY ESCALATED.

BUILDINGS BEGAN TO SHAKE, AND THE DAY MORPHED INTO NIGHT

AS BLACK CLOUDS DESCENDED ON THE CITY.

MOUNT VESUVIUS RELENTLESSLY BEGAN TO RAIN DOWN

SCORCHING HOT VOLCANIC ASH, GAS, AND ROCKS ONTO POMPEII.

THIS ONSLAUGHT LASTED FOR 12 HOURS STRAIGHT.

THE TOWNSPEOPLE ATTEMPTED TO RUN,

BUT MANY WERE HELPLESS

AGAINST THIS ALL-POWERFUL MONSTER.

ALTHOUGH THE PEOPLE OF POMPEII HAD NO IDEA

THAT A DISASTER WAS IMMINENT, THERE WERE SOME WARNING SIGNS.

SIXTEEN YEARS BEFORE THE ERUPTION,

A MASSIVE EARTHQUAKE SHOOK POMPEII.

IN FACT, DAMAGE TO THE TOWN WAS STILL BEING REPAIRED

WHEN VESUVIUS ERUPTED.

AND, ALARMINGLY, OVER THE PAST FEW YEARS,

ITALY HAS BEEN ROCKED BY SIMILAR DEADLY EARTHQUAKES.

COULD THEY BE A SIGN OF TROUBLE

BREWING IN THE VOLCANIC CHAIN BENEATH US?

TO FIND OUT, STEFAN AND I ARE GOING TO DEPLOY A SERIES

OF SEISMIC TOOLS ACROSS THE REGION

AND HUNT FOR SIGNS THAT SOMETHING DANGEROUS

IS BREWING BENEATH THE SURFACE.

HERE WE GO, STEFAN.

WHAT AN INCREDIBLE VIEW.

I THINK THIS IS A GOOD SPOT ON THE CALDERA

TO TAKE MEASUREMENTS.

YOU'RE ON HARD ROCK. YEAH.

THAT'S GOING TO CARRY SEISMIC SIGNALS REALLY WELL.

OKAY, HERE, LET ME BURY THIS SEISMOMETER.

OUR FIRST TEST WILL GAUGE GROUND STABILITY

ON THE LIP OF ITALY'S MOST NOTORIOUS VOLCANO

TO SEE IF THERE'S ACTIVITY THAT COULD INDICATE

POMPEII'S TELLTALE TREMORS ARE HAPPENING AGAIN.

OUR PORTABLE SEISMOMETER CONSISTS OF A LARGE GEOPHONE

THAT'S HOOKED UP TO A LAPTOP.

IT WILL MEASURE SEISMIC ACTIVITY OCCURRING UNDER VESUVIUS,

INCLUDING MICROTREMORS

WHICH OFTEN SIGNAL AN EARTHQUAKE

OR ERUPTION IS IMMINENT.

THIS IS ONE OF THE BEST PIECES OF TECHNOLOGY YOU CAN USE

FOR WHAT WE'RE TRYING TO ACCOMPLISH HERE.

AND I THINK IT'S IMPORTANT TO START HERE

BECAUSE WE CAN KIND OF UNDERSTAND

THE HISTORY OF THIS VOLCANO.

AND, HOPEFULLY, PREDICT WHAT'S GOING TO HAPPEN IN THE FUTURE.

GREAT.IT LOOKS LIKE WE'RE RECORDING,

AND EVERY 5 SECONDS

IT'S TAKING THE AVERAGE

OF EVERYTHING THAT IT'S EXPERIENCING.

SO IF YOU WOULD TAP IT FOR 5 SECONDS,

THEN YOU WOULD SEE A BIG SPIKE

BECAUSE A LITTLE SOURCE HERE IS EQUIVALENT

TO A BIG SOURCE UNDERGROUND.

SO WE NEED TO RUN IT FOR A PERIOD OF TIME

THAT'S LONG ENOUGH FOR US TO,

HOPEFULLY, COLLECT SOME OF THESE MICROTREMORS.

BUT AFTER A WEEK, YOU KNOW, WE CAN COME BACK,

GRAB THE UNIT, ANALYZE THE DATA AND SEE WHAT WE FIND.

WHICH IS FANTASTIC BECAUSE THIS WILL HELP US UNDERSTAND

HOW ACTIVE THIS VOLCANO IS RIGHT NOW.

YEAH. ALL RIGHT.

LET'S PACK IT UP AND GET OUT OF HERE.

ALL RIGHT.

"WIRED" MAGAZINE RECENTLY RANKED MOUNT VESUVIUS

THE FIFTH MOST DANGEROUS VOLCANO ON EARTH.

AND THE MOST LIKELY TO RELEASE THE BIGGEST ERUPTION

AND AFFECT THE GREATEST NUMBER OF PEOPLE--

IT'S LESSER-KNOWN SIBLING, CAMPI FLEGREI.

SO NEXT, STEFAN AND I ARE HEADING TO ITALY'S VOLCANIC

GROUND ZERO,

10 MILES TO THE WEST.

LOOK AT THAT!UH, OH!

OH, MY GOODNESS!

IT'S AN AREA OF STEAMING MUD POOLS

AT THE HEART OF CAMPI FLEGREI

CALLED THE SOLFATARA, MEANING "LAND OF SULFUR."

THIS IS ABSOLUTELY NUTS!

THIS PLACE IS LITERALLY MYTHICAL.

IT'S THE TRADITIONAL HOME OF VULCAN, THE ROMAN GOD OF FIRE,

AND IT'S EASY TO SEE WHY ANCIENT ROMANS

VIEWED THIS PLACE AS HELL ON EARTH.

SOUNDS LIKE A BIG STEAM ENGINE.

YEAH. DO YOU SMELL THE SULFUR?

I CAN.

SOLFATARA IS JUST ONE OF 24 CRATERS

THAT MAKE UP THE CAMPI FLEGREI SYSTEM,

AND IT'S POCKMARKED WITH STEAMING VENTS

KNOWN AS FUMAROLES,

WHICH ARE CREATED BY VOLCANIC GASES

SPEWING OUT FROM DEEP UNDERGROUND.

YOU CAN FEEL THE HEAT EMANATING FROM THE GROUND.

YOU FEEL THAT?

OH, IT'S HOT.

IN FACT, THE SOLFATARA CRATER RECENTLY

CLAIMED THE LIVES OF THREE PEOPLE

WHO FELL INTO ONE OF IT'S STEAMING HOT PITS,

BEGGING THE QUESTION,

IS THIS PLACE GETTING EVEN MORE DANGEROUS?

OUR FIRST STEP IS TO COMPARE THE CURRENT TEMPERATURE

DOWN INSIDE THE FUMAROLE AGAINST PREVIOUS READINGS.

SO IF WE CAN BE IN THE THERMOCOUPLE,

DON'T GET TOO CLOSE.

IF YOU FALL IN, I DON'T WANT TO FISH OUT

YOUR DE-SKINNED BODY.

WELL, I THOUGHT YOU WE'RE GOING TO BE THE ONE TO THROW IT IN.

YOU'RE NOT GOING TO LIKE THIS, STEFAN,

BUT I'M BETTER AT READING THE TEMPERATURE.

TO GET A PRECISE MEASUREMENT OF THE WATER TEMPERATURE

WE'LL USE A HIGH-TECH THERMOMETER THAT CAN EXTEND

INTO HARD-TO-REACH AND DANGEROUS SPOTS.

A DECADE AGO, THE HIGH TEMPERATURE

RECORDED IN THESE FUMAROLES

WAS 203 DEGREES FAHRENHEIT.

IF OUR READING IS LOWER OR ABOUT EVEN WITH THAT,

IT WOULD SUGGEST CONDITIONS UNDERGROUND HERE

HAVEN'T CHANGED ALL THAT MUCH,

BUT, IF THE TEMPERATURE COMES BACK SIGNIFICANTLY HIGHER,

THAT COULD BE A SIGN OF SERIOUS TROUBLE.

OKAY, BE REALLY CAREFUL OVER THERE!

ANYWHERE RIGHT UP HERE.

AH!

I CAN'T EVEN HEAR MYSELF TALK!

IT'S SO FREAKING LOUD.

ARE WE READY?

IS THE WORLD'S MOST DANGEROUS SUPERVOLCANO

WARMING UP TO UNLEASH CARNAGE ON A MONSTROUS SCALE,

AND WILL THE PEOPLE OF NAPLES BE CAUGHT OFF GUARD

LIKE THEIR PREDECESSORS IN POMPEII?

IT'S GOING UP NOW.YEAH, IT'S GOING UP.

155 AND RISING.

IT'S GOING UP QUICK.

AND LATER, OUR QUEST TO CRACK THE CODE OF ITALY'S SUPERVOLCANO

TAKES US INTO THE ANCIENT TUNNEL TO HELL.

OH, BROTHER.

HOLY MOLY, LOOK AT THIS.

WE'RE ON ITALY'S WEST COAST

STANDING ON TOP OF THE WORLD'S MOST DANGEROUS SUPERVOLCANO.

IF THIS VOLCANO BLOWS, IT COULD BE MORE DEVASTATING

THAN THE ERUPTION THAT DECIMATED POMPEII.

TO GET A BETTER IDEA OF WHAT'S BREWING BELOW,

WE'RE MEASURING THE WATER TEMPERATURE

INSIDE A STEAMING HOT FUMAROLE.

A DECADE AGO, IT CLOCKED IN AT A SCORCHING

203 DEGREES FAHRENHEIT,

JUST 9 DEGREES SHY OF THE BOILING POINT.

IF OUR READINGS ARE MUCH HIGHER, THAT COULD SPELL DISASTER

FOR ITALY, EUROPE, OR EVEN THE ENTIRE PLANET.

IT'S GOING UP NOW.YEAH, IT'S GOING UP.

155 AND RISING.

IT'S GOING UP QUICK.

161. OH, WOW.

163.

JUST THE FACT THAT THIS THING IS SO INTENSE,

IT MAKES IT VERY CLEAR

THAT THERE IT HOT MAGMA

VERY CLOSE TO THE SURFACE RIGHT HERE.

SCIENTISTS BELIEVE THE MAGMA CHAMBER

UNDER CAMPI FLEGREI COULD BE MASSIVE,

AND IN THE PAST, EMITTED MORE MAGMA THAN MOUNT VESUVIUS.

NO WONDER THE TEMPERATURE READINGS HERE ARE SO HIGH.

173. OH, MY GOSH.

JUST SITTING HERE ON THESE ROCKS, IT'S SUPER HOT.

YEAH.

IT'S OVER 200, AND IT'S STILL GOING UP!

UNBELIEVABLE.

HOLY CRAP.

IF YOU FELL IN, YOU WOULDN'T LAST, LIKE, TEN SECONDS.

205.

WE'RE 7 DEGREES AWAY FROM BOILING.

THE BOILING POINT IS 212 DEGREES FAHRENHEIT.

IT'S GOING TO HIT IT.

YEAH.

TWO DEGREES AWAY NOW.

I DON'T KNOW WHY I'M SO EXCITED. I WANT IT TO GET

HOTTER AND HOTTER. POINT ONE.

212! 212!

WAY TO GO. WHOO!

INCREDIBLE.

ACCORDING TO OUR READINGS,

THE WATER BUBBLING IN THESE MUD POOLS

IS LITERALLY BOILING HOT.

WATCHING THE NUMBERS RISE FEELS EXCITING,

BUT IT SUDDENLY DAWNS ON US WHAT THIS ACTUALLY MEANS.

THIS IS ONE PIECE OF A TERRIFYING PUZZLE

THAT IS TELL US THIS MONSTER MIGHT BE WAKING UP.

AND IT DOESN'T STOP THERE.

IT'S MOVING FASTER NOW.

HOLY CRAP!

THE FACT THAT WE HAVE WATER AND STEAM

COMING OUT HERE AT A TEMPERATURE GREATER THAN BOILING,

YOU KNOW, THIS HAS RISEN ALL THE WAY FROM THE MANTLE PLUME

AND IT'S STILL THAT HOT.

IT TAKES A LOT OF ENERGY TO MAKE WATER TURN INTO GAS.

I DON'T THINK IT'S GOING TO GO ABOVE 220.

SO 219, WELL GIVE OR TAKE A FEW DEGREES,

I THINK THAT'S THE TEMPERATURE WE GOT.

SEVERAL DEGREES ABOVE BOILING.

AND 16 DEGREES HOTTER THAN THE READINGS TAKEN HERE

A DECADE AGO.

SCIENTISTS HAVE PREVIOUSLY SEEN

THIS KIND OF DRAMATIC RISE IN TEMPERATURE

JUST BEFORE AN ERUPTION.

SO IS THIS A SIGN OF IMPENDING DOOM?

IT'S CRAZY THAT PEOPLE AREN'T AWARE

THAT THIS COULD POTENTIALLY EXPLODE.

AND EVEN CRAZIER THAT THERE'S HOUSES ALL OVER THIS REGION.

YEAH, ALL ON THE RIM OF THIS CRATER HERE.

AROUND 40,000 YEARS AGO, THE CALDERA HERE WAS FORMED

BY ONE OF THE MOST POWERFUL ERUPTIONS OF ALL TIME.

THE BLAST EXPELLED ALMOST A TRILLION GALLONS OF MOLTEN ROCK

AND UNLEASHED JUST AS MUCH SULFUR INTO THE ATMOSPHERE,

DARKENING THE SKIES ACROSS EUROPE

AND TRIGGERING A GLOBAL VOLCANIC WINTER.

IT MAY HAVE COMPLETELY WIPED OUT THE EUROPEAN NEANDERTHALS.

OVER THE CENTURIES, CAMPI FLEGREI

HAS REMAINED ACTIVE

WITH MORE ERUPTIONS OCCURRING ROUGHLY

12,000, 8,000, AND 4,000 YEARS AGO.

THE MOST RECENT ERUPTION OCCURRED

LESS THAN 500 YEARS AGO,

IN 1538, LASTING 8 STRAIGHT DAYS

AND SENDING ASH ALL ACROSS SOUTHERN ITALY.

I THINK THE THING THAT'S REALLY DECEIVING

ABOUT THIS WHOLE SYSTEM, TOO,

IS THAT PEOPLE ARE PROBABLY USED TO GIANT VOLCANOES

ERUPTING FROM THE TOP,

WHAT THEY'RE NOT USED TO ARE THESE FLATTENED CRATERS

ESSENTIALLY, LIKE, ERUPTING AGAIN.

OR ARGUABLY...I MEAN, IT COULD ERUPT ANYWHERE.

...IT WOULD JUST BE LIKE A BOMB GOING OFF.

IT SEEMS CLEAR THAT THE VOLCANIC ACTIVITY UNDER THIS CRATER

IS INCREASING, AND FAST.

BUT IS THE ENTIRE VOLCANO HEATING UP

AND GETTING READY TO UNLEASH CARNAGE

AS DEADLY AS THE DESTRUCTION OF POMPEII?

DURING THE ERUPTION IN 79 A.D.,

IT'S REPORTED THAT SURGES OF SUPERHEATED GAS

SPEWED OUT OF VESUVIUS AT 100 MILES AN HOUR.

TEMPERATURES IN POMPEII SOARED TO 570 DEGREES.

HEAT FROM THESE WAVES OF TOXIC ASH AND GASES,

KNOWN AS PYROCLASTIC FLOWS, KILLED EVERYONE IN IT'S PATH--

THEY'RE BODIES ETERNALLY FROZEN IN HORRIFYING, CONTORTED POSES.

TO FIGURE OUT WHEN CAMPI FLEGREI MIGHT BLOW,

WE NEED TO FIND OUT IF THE HEAT AT THE SOLFATARA CRATER

IS JUST A FREAK OCCURRENCE,

OR IF THIS SLEEPING GIANT IS HEATING UP ANYWHERE ELSE.

WE'LL USE THE HANDHELD THERMAL CAMERA TO GET EVEN CLOSER

TO THE HEART OF THE VOLCANO, THE RIM OF THE CRATER,

TO DETERMINE WHAT'S GOING ON INSIDE CAMPI FLEGREI.

WALK OVER TO THAT FUMAROLE, SEE WHAT READING YOU GET.

PUTTING ME IN DANGER AGAIN, ROB.

OH, YEAH.

80, 89 DEGREES.

89 CELSIUS, RIGHT?

93-- YEAH, THIS IS ALL CELSIUS.

105.

THAT'S 221 DEGREES FAHRENHEIT.

THAT'S GOT TO BE SOME SORT OF RECORD.

YOU'RE POINTING IT RIGHT AT THAT, RIGHT THERE?

I JUST GOT 135.

I'M FOCUSED SPECIFICALLY ON THE FUMAROLE RIGHT THERE.

135 CELSIUS IS 275 DEGREES FAHRENHEIT,

OUR HOTTEST READING YET.

THIS IS GETTING SCARY.

THE WHOLE GROUND IS STEAMING.

OH, MAN. IT'S LIKE THERE'S A FIRE

LIT UNDERNEATH IT.OH, MY GOD.

I MEAN, LOOK AT THE TEXTURE THERE TOO,

JUST THE WAY THE THERMAL IMAGE IS DIFFUSING ACROSS THE ROCK.

THE TEMPERATURE READINGS OF THIS FUMAROLE ARE OFF THE CHARTS

AND SEEM TO BE RISING FAST.

THAT'S TROUBLING NEWS FOR ANYONE PLANNING

TO RETIRE TO THE AMALFI COAST,

BUT THIS FUMAROLE IS JUST ONE SMALL FLICKER

IN A RAGING INFERNO.

WE HAVE A WHOLE CRATER BEHIND US.

IF YOU TURN AROUND HERE AND LOOK AT THE THERMAL IMAGE

FOR THE WHOLE CRATER.

OH!

THIS IS COMPLETELY RED.

IS THIS FIELD OF FIRE A GIANT GEOLOGICAL RED FLAG?

THIS IS PRETTY SCARY.

AND, IF SO, WHAT IS IT TRYING TO TELL US?

IS ITALY'S COLOSSAL SUPERVOLCANO ABOUT TO BLOW?

IF IT DOES, IT WOULDN'T BE THE FIRST TIME.

THIS CALDERA SHROUDED EUROPE IN A CLOUD OF ASH AT LEAST

ONCE IN THE DISTANT PAST.

AND NOW, WITH 6 MILLION PEOPLE LIVING CLOSEBY

AND 700 MILLION ACROSS EUROPE,

THE STAKES HAVE NEVER BEEN HIGHER.

SO STEFAN AND I ARE IN A PLACE

THE MIDDLE OF THE SOLFATARA CRATER,

LOOKING FOR SIGNS OF AN IMMINENT ERUPTION.

IF YOU LOOK AT THE THERMAL IMAGE FOR THE WHOLE CRATER...

OH! LOOK AT THIS!

THIS IS COMPLETELY RED, PURPLE, YELLOW.

OH, MY GOODNESS.

I MEAN, IT'S... THAT MOUND OVER THERE

WE WERE WALKING ON EARLIER, THAT THING IS LIKE A BEACON.

IT LOOKS LIKE WE'RE ON A LAVA FIELD OR SOMETHING.

THERE'S A LAVA FIELD BELOW US.

I MEAN, THIS IS PRETTY SCARY.

THIS IS A GREAT INDICATION

THAT THERE'S A LOT OF VOLCANIC ACTIVITY HERE IN ITALY.

YEAH, AND I THINK WE'VE GOT TO MOVE

BECAUSE I'M BURNING MY PANT LEGS RIGHT AT THE MOMENT.

CLEARLY, THIS SPOT IS HIGHLY ACTIVE,

BUT THIS IS JUST ONE OF 24 CRATERS

SPREAD OVER CAMPI FLEGREI'S 8-MILE DIAMETER.

TO GET A BETTER SENSE OF HOW EXTENSIVE

AND IMMEDIATE THE DANGER IS,

WE NEED TO EXPAND OUR SEARCH TO OTHER HOT SPOTS IN THE REGION,

SO STEFAN AND I WILL DIVIDE AND CONQUER.

WHILE THE CITY OF POMPEII WAS BURIED ALIVE,

VOLCANIC ACTIVITY HERE CAUSED THE TOWN OF BAIA

TO PLUNGE DEEP BENEATH THE WAVES

ROUGHLY 1,500 YEARS AGO.

WE'RE GOING RIGHT NOW TO BAIA.

IT'S AN UNDERGROUND ARCHAEOLOGICAL SITE.

ESSENTIALLY, THIS WAS LIKE THE LAS VEGAS OF ANCIENT TIMES.

THE ROMANS WOULD COME HERE, HAVE SPAS.

BUT RIGHT NOW, IT'S COMPLETELY UNDERWATER.

THIS ONCE-THRIVING RESORT WAS A GETAWAY

FOR THE RICH WITH VISITORS RUMORED

TO HAVE INCLUDED JULIUS CAESAR AND CLEOPATRA.

WITH CASINOS, OUTDOOR SWIMMING POOLS, AND GRAND VILLAS,

BAIA WAS KNOWN AS A PLACE OF EXTREME LUXURY AS WELL AS VICE.

BUT NOW, SUNKEN DEEP UNDERWATER,

THIS STUNNING ARCHAEOLOGICAL SITE

IS A TERRIFYING REMINDER OF THE POWER

AND FORCE OF A SUPERVOLCANO.

I'LL BE LOOKING FOR EVIDENCE OF ONGOING VOLCANIC ACTIVITY,

CLUES THAT MIGHT INDICATE WHETHER CAMPI FLEGREI

IS ABOUT TO ROAR BACK TO LIFE.

HERE WE GO.

IT'S UNBELIEVABLE, BUT THIS TOWN IS NOW

AT LEAST 15 FEET BELOW SEA LEVEL.

BAIA SANK BECAUSE OF THE EMPTYING OF MAGMA CHAMBERS

DEEP BENEATH THE EARTH'S CRUST.

SCIENTISTS CALL THE RISE AND FALL OF EARTH'S SURFACE

CAUSED BY THE MOVEMENT OF MAGMA CHAMBERS "BRADYSEISM."

THIS DRAMATIC DROP IN GROUND LEVEL

SHOWS THE TREMENDOUS FLUCTUATION OF MAGMA CHAMBERS UNDERGROUND.

RIGHT AWAY, I'M STUCK BY HOW WELL PRESERVED THE RUINS ARE.

A QUICK DUSTING AWAY OF ROCKS AND SHELLS

REVEALS AN ELABORATE TILE FLOOR.

JUST A FEW FEET AWAY, I SPOT AN INCREDIBLE

SET OF LIFE-SIZE STATUES.

SCULPTURES LIKE THESE WERE ONCE A SIGN OF PROSPERITY AND LEISURE

BEFORE THEY ENDED UP IN A WATERY GRAVE.

COULD OTHER PARTS OF THE ITALIAN COAST

SOON FALL VICTIM TO A SIMILAR FATE?

AT FIRST, I DON'T SEE ANY EVIDENCE

OF GEOTHERMAL ACTIVITY HERE.

IT ALL SEEMS SO CALM AND PEACEFUL.

BUT THE TRUTH IS, THERE'S A DANGEROUS MAGMATIC MONSTER

STILL LURKING BENEATH THE SURFACE,

AND IT MAY BE ABOUT TO REVEAL ITSELF.

I SPOT BUBBLES CHURNING UP FROM UNDER THE ROCKS

ON THE SEA FLOOR, HUNDREDS OF THEM.

AND WHAT'S EVEN MORE CURIOUS, THEY'RE WARM TO THE TOUCH.

THEN, I SPOT A MASSIVE VENT

SPEWING OUT BOILING HOT LIQUID INTO THE SEA.

THE WATER ABOVE THIS AREA IS SO HOT,

I CAN'T KEEP MY HAND IN PLACE VERY LONG.

WOW.

AH!

THE WHOLE GROUND WAS BUBBLING--

HUNDREDS AND HUNDREDS OF LITTLE SMALL BUBBLES

COMING OUT ALL OVER THIS GIANT FIELD.

AND EVERY ONCE IN A WHILE, I WOULD PUT MY HAND DOWN

ON A ROCK,

AND IT WAS HOT.

YOU COULDN'T GET YOUR HAND BUT MAYBE THIS FAR FROM IT.

SO THERE'S NO DOUBT IN MY MIND

THAT THIS ENTIRE AREA

IS EXTREMELY ACTIVE.

ARE THE PEOPLE OF NAPLES IN DANGER

OF HAVING ANOTHER SEISMIC ERUPTION?

I THINK THAT'S WHAT WE'VE GOT TO FIGURE OUT.

WHILE I'VE BEEN INVESTIGATING AN ABANDONED CITY,

STEFAN HAS HEARD SCIENTISTS HAVE JUST DISCOVERED

A DANGEROUS HOT SPOT

UNDERNEATH THE BUSY TOWN OF POZZUOLI.

DOES THIS TERRIFYING DISCOVERY SIGNAL DISASTER

FOR THIS ANCIENT TOWN?

STEFAN AND I ARE SEARCHING FOR CLUES

THAT VOLCANIC ACTIVITY UNDER NAPLES

IS ON THE RISE AGAIN--

A TERRIFYING PROSPECT FOR THE MILLIONS OF PEOPLE

LIVING IN CAMPI FLEGREI'S LINE OF FIRE.

THIS ANCIENT MARKETPLACE FROM THE SECOND CENTURY A.D.

IS IN THE HEART OF POZZUOLI AND WAS ONCE UNDERWATER

JUST LIKE THE CITY OF BAIA.

LOOK AT THE SEASHELLS ON HERE.

YOU CAN SEE HERE THAT THESE COLUMNS USED TO BE UNDERWATER.

BUT, DUE TO EXTRAORDINARY SEISMIC SHIFTS,

IT HAS RISEN BACK ABOVE GROUND.

STEFAN IS INVESTIGATING THE MAGMA CHAMBERS DEEP UNDERGROUND

TO FIGURE OUT IF POZZUOLI WILL BE TRANSFORMED,

YET AGAIN, INTO AN UNDERWATER CITY.

AND, HE'S HEARD WORRYING NEWS THAT SCIENTISTS HAVE JUST FOUND

A GIANT HOT SPOT OF BOILING LIQUID

BENEATH THIS BUSTLING TOWN.

SO I HAVE THIS G.P.S. ANTENNA HERE

AND WE'RE GOING TO TRY AND SEE

AND TRACK THE ELEVATION CHANGE AT THIS SITE

OVER THE COURSE OF THE NEXT FEW DAYS.

MONITORING THE GROUND MOVEMENT HERE HELPS US UNDERSTAND

THE RISE AND FALL OF MAGMA BELOW GROUND.

WHEN MAGMA MOVES UPWARD, IT CAN INDICATE THAT A VOLCANO

IS READY TO BLOW,

AND A SEISMIC CATASTROPHE IS IMMINENT.

WE WILL BE ABLE TO SEE WHETHER THE GROUND INCREASES

IN ELEVATION

OR DECREASES IN ELEVATION OVER THE NEXT FEW DAYS.

AND IF WE GET A SIZABLE INCREASE, THEN WE KNOW

THAT THERE IS SOME SERIOUS VOLCANIC ACTIVITY

HAPPENING UNDERNEATH OUR FEET RIGHT NOW.

LOOKING AROUND THIS MARKETPLACE,

POZZUOLI'S HAUNTING PAST COMES TO LIFE.

GEOLOGISTS WERE STUMPED BY THESE THREE ICONIC COLUMNS

FOR DECADES.

THEY HAD NO IDEA HOW THESE COLUMNS

COULD HAVE EROSION FROM THE SEA.

IT WASN'T UNTIL SCIENTISTS FIGURED OUT THAT GROUND LEVEL

IS AFFECTED BY THE RISE AND FALL OF MAGMA BENEATH IT

THAT THIS MYSTERY WAS SOLVED.

IT MUST HAVE BEEN HORRIFIC FOR THE PEOPLE OF POZZUOLI,

WATCHING THEIR TOWN SINK 22 FEET INTO THE SEA.

AND, HOPEFULLY, IT'S AN EVENT THAT WON'T BE REPEATED.

WE'VE GOT SOME WATER BUBBLING OUT.

THIS PLACE IS STILL VERY, VERY GEOLOGICALLY ACTIVE.

THIS MARKETPLACE IS A HAUNTING REMINDER

OF THE DESTRUCTIVE POWER OF MOTHER NATURE,

AND THAT POWER HAS INFLUENCED HUMAN CIVILIZATION

IN THIS REGION SINCE THE DAWN OF RECORDED HISTORY.

THERE'S ANOTHER SITE NEARBY THAT SHOWS JUST HOW DEEPLY

ITALY'S VOLCANIC DANGERS ARE WOVEN INTO HUMAN MYTH.

THE GROTTA DELLA SIBILLA, OR "SIBYL'S CAVE,"

IS A MASSIVE SERIES OF ANCIENT TUNNELS

THAT SITS RIGHT IN THE HEART OF CAMPI FLEGREI.

IT'S KNOWN TO THE LOCALS AS THE TUNNEL TO HELL...

BUONGIORNO.

HI. BUONGIORNO.

...AND THESE GENTLEMAN HOLD THE ONLY KEY.

GOOD TO MEET YOU GUYS.

SO, YOU GUYS GOING TO SHOW US TO THE ENTRANCE OF HELL?

SURE. OKAY.

LET'S DO IT.

ACCORDING TO FOLKLORE, THERE'S A RIVER DEEP INSIDE THE TUNNELS

THAT BOILS LIKE A CAULDRON.

SOME SAY IT'S THE LEGENDARY RIVER STYX,

WHICH, ACCORDING TO GREEK MYTHOLOGY,

LEADS FROM THE LAND OF THE LIVING TO THE LAND OF THE DEAD.

BUT IS THAT JUST A MYTH,

OR COULD THERE ACTUALLY BE A BOILING RIVER

HIDDEN INSIDE THESE TUNNELS?

AND, IF THERE IS, WILL IT'S TEMPERATURE BE THE CRYSTAL BALL

THAT FORETELLS AN ERUPTION DEADLIER THAN POMPEII?

BUENA FORTUNA.

OKAY. GRAZI.

PREGO.YEAH.

THESE GUYS MAY ALREADY KNOW THE ANSWER,

AND IT SEEMS THEY AREN'T JOINING US.

ALL RIGHT. BEFORE WE GO IN,

EVERY SINGLE ARCHAEOLOGIST

HAS A DIFFERENT THEORY ABOUT THIS PLACE.

ALL OF IT KIND OF LEADS BACK TO THIS IDEA

OF AN ENTRANCE TO HELL.

THIS IDEA THAT IT CAME FROM, SAY, DANTE'S "INFERNO"--

HE WRITES ABOUT THE RIVER OF FIRE,

ESSENTIALLY A RIVER THAT WOULD BOIL THE SOULS OF THE DEPARTED.

SOUNDS PRETTY SPOOKY, BUT IT SOUNDS LIKE

THERE'S DEFINITELY GOING TO BE WATER DOWN THERE,

ACCORDING TO THESE LEGENDS.

ALL RIGHT. LET'S DO THIS.

OH, BOY.

THIS IS A MASSIVE UNDERTAKING TO DIG THIS THING.

THE ESTIMATES GO BACK TO 500 B.C.

A LONG TIME AGO.IT'S LIKE THE FOUNDING

OF THE ROMAN EMPIRE.WELL, BEFORE THAT.

ACCORDING TO GRECO-ROMAN MYTHOLOGY,

THIS IS WHERE THE TROJAN HERO AENEAS

EMBARKED ON HIS JOURNEY INTO HADES WITH THE SIBYL,

OR FORTUNE TELLER, AT HIS SIDE.

CHECK THIS OUT. YEAH.

THERE'S ALL OF THESE LITTLE HOLES.

YOU THINK THEY COULD HAVE PUT CANDLES

OR SOMETHING IN HERE?

YEAH.

THIS WAS POTENTIALLY USED AS SOME SORT OF...

ACTUALLY, THAT MAKES SENSE....RELIGIOUS PURPOSE.

YEAH, THAT MAKES SENSE.YOU KNOW, I MEAN,

THEY'RE ALL... EVENLY SPACED.

THE LIGHT WOULD CAST UPWARDS.

THE SIBYL THAT LURKED IN THESE CAVES WAS SAID

TO BE SO STRIKINGLY BEAUTIFUL THAT THE SUN GOD,

APOLLO, FELL IN LOVE WITH HER

AND OFFERED HER ONE WISH FOR HER VIRGINITY.

THE STORY GOES THAT SHE ASKED TO LIVE FOREVER,

BUT SHE FORGOT TO ASK FOR ETERNAL YOUTH.

TRUE TO HER WISH, THE SIBYL LIVED TO BE OVER 700 YEARS OLD

BUT BECAME A TROUBLED WOMAN, AGING, BUT SHE COULD NOT DIE.

DESCRIBED AS A MAD PROPHET, IT'S SAID SHE COULD BE FOUND

EITHER RECLINED ON A ROCK SINGING,

OR SCRIBBLING PROPHECIES ON LEAVES.

THE SIBYL PLACED THESE PREDICTIONS

AT THE ENTRANCE TO HER CAVE.

BUT THESE PRECIOUS PROPHECIES WOULD OFTEN BE BLOWN AWAY

BY VAPORS BEFORE HER FOLLOWERS COULD READ THEIR FATE.

AND THE LIKELY SOURCE OF THOSE VAPORS?

STEAM FROM VOLCANIC ACTIVITY.

IF CAMPI FLEGREI, WHICH IS DIRECTLY UNDERNEATH RIGHT NOW,

WAS MORE VOLCANICALLY ACTIVE NEAR THE SURFACE IN THIS AREA,

YOU KNOW, THERE COULD HAVE BEEN SUPERHEATED WATER,

SULFUROUS GASES, ET CETERA.

THERE HAD TO HAVE BEEN AN INDICATOR

AS TO WHY THEY SHOULD DIG DOWN HERE.

DO YOU SEE ANY WATER MARKS ON THE WALLS, THOUGH?

YOU SEE RIGHT HERE, ESPECIALLY.

THAT WOULD HAPPEN WITH WATER.

IT LOOK LIKE THERE MIGHT HAVE BEEN WATER, AT ONE POINT,

6, 7 FEET HIGH,

AND THEN WITH THIS HUGE TUNNEL HERE YOU STILL HAVE

ANOTHER 6, 7 FEET ABOVE YOU.

OH. YOU SEE THAT?

YEAH, IT'S LIKE A SYMBOL.

IT'S LIKE ANCIENT GRAFFITI, IS WHAT THAT LOOKS LIKE TO ME.

THIS DOESN'T LOOK RECENT AT ALL.

YEAH. YOU CAN TELL

IT'S NOT MODERN BASED OFF THE FACT THAT

IF THIS WAS NEW, THAT WOULD BE FRESH ROCK ON THE INSIDE.

IN THEIR EFFORT TO MAKE SENSE OF THIS

ALL-POWERFUL VOLCANIC FORCE,

ANCIENT PEOPLE WOVE IT INTO MYTH

AND TURNED THIS CAVE INTO A SACRED SITE.

IT'S ALSO GETTING QUITE A BIT HOTTER IN HERE, DON'T YOU THINK?

YEAH.IT WAS COOL BACK THERE.

THE TEMPERATURE AND HUMIDITY IN CAVES

TENDS TO STAY THE SAME YEAR-ROUND

BECAUSE THEY'RE NOT AFFECTED BY SURFACE WEATHER PATTERNS,

BUT NOT HERE.

IT'S HOT NOW.I'D SAY HOTTER AND MORE HUMID.

IT IS MORE HUMID.

TYPICALLY, THE OPPOSITE IN A CAVE SYSTEM.

WHICH MAKES ME WONDER IF THERE COULD BE SOME TRUTH

TO THIS LEGEND OF THE BOILING RIVER.

OH, BROTHER.

HOLY MOLY! LOOK AT THIS.

I'LL GO IN FIRST.

YEAH, GOOD.

THAT'S WHAT I WAS WANTING YOU TO DO.

IT'S GETTING WARMER.

I'M COMING IN WITH YOU.

DO YOU SMELL ANY GASES OR ANYTHING?

NO, BUT DEFINITELY AM STARTING TO SWEAT.

IT'S PRETTY STEEP COMING DOWN HERE.

IT STARTS GOING DOWN REALLY QUICK.

REALLY?

LIKE, I UNDERSTAND WHY THIS IS A JOURNEY INTO HELL.

AS WE DESCEND FURTHER, THE TEMPERATURE KEEPS RISING

AND THE PASSAGE NARROWS EVEN MORE.

IT FEELS LIKE IT MIGHT BE A DEAD END.

HOLY MOLY.

WE'RE JUST OUTSIDE OF NAPLES, ITALY

INVESTIGATING A SERIES OF SIGNS THAT CAMPI FLEGREI,

WHICH HAS BEEN CALLED THE MOST DANGEROUS VOLCANO ON EARTH,

IS COMING BACK TO LIFE.

STEFAN AND I ARE EXPLORING UNDERGROUND PASSAGES

THE ANCIENT GREEKS BELIEVED WERE A PORTAL TO THE UNDERWORLD.

I CAN UNDERSTAND WHY THIS IS A JOURNEY INTO HELL.

LEGEND HAS IT, THERE'S A BOILING RIVER DOWN HERE,

AND WE MAY HAVE JUST FOUND IT.

HOLY MOLY.

WOW. LOOK AT THAT.

THIS CONTINUES BACK, TOO.

DOES IT? YEAH.

SO THE LEGENDS OF AN UNDERGROUND RIVER HERE ARE TRUE.

NOW THE QUESTION IS, HOW HOT IS IT?

I THINK WE CAN JUST START WITH THE THERMAL CAMERA,

SEE IF WE CAN SEE A HOT SPOT IN HERE

INDICATING VOLCANIC ACTIVITY.

FIRST, WE'LL USE A PORTABLE ATTACHMENT

THAT TRANSFORMS AN ORDINARY SMARTPHONE

INTO A MOBILE THERMAL CAMERA.

ALL RIGHT. LET'S HOPE THIS THING WORKS.

THE DISPLAY CAN NOW GIVE US A VISUAL INDICATION

OF TEMPERATURE DIFFERENCES THROUGHOUT THE TUNNEL.

BLUE MEANS COOL, RED MEANS WARM, AND WHITE IS WHITE HOT.

WELL, THE WATER IS DEFINITELY HOTTER

THAN THE REST OF THE TUNNEL.

AND THAT ACTUALLY LOOKS LIKE A LAVA LAKE.

THE WATER TEMPERATURE IN A CAVE

WOULD NORMALLY BE AT OR BELOW AIR TEMPERATURE,

WHICH IN HERE IS 67 DEGREES FAHRENHEIT.

UNLESS, OF COURSE, SOMETHING ELSE IS HEATING THE WATER

FROM BELOW.

READY?

HOLD ON, HOLD ON. THERE IT GOES, IT'S READING.

IT'S DETECTING THE WATER.

IT'S DEFINITELY GOING UP.

IT WAS AT 70 DEGREES FAHRENHEIT AND IT'S GOING UP TO 74,

75, 75.9.

76.

I WOULD EXPECT THIS TO BE MUCH COOLER

FOR AN UNDERGROUND TUNNEL, YOU KNOW?

THIS WATER IS ACTUALLY ALMOST 10 DEGREES HOTTER THAN THE AIR.

YEAH. THIS IS UNUSUAL.

CLEARLY, THERE'S SOME GEOTHERMAL ACTIVITY DOWN HERE.

YEAH, I AGREE.

IT MAY NOT BE BOILING AT THE MOMENT,

BUT THE WARM WATER IN THIS SO-CALLED TUNNEL TO HELL

IS ANOTHER WORRYING SIGNAL THAT CAMPI FLEGREI

IS PREPARING FOR AN ENCORE PERFORMANCE.

BUT THE QUESTION IS, WILL IT ERUPT ANYTIME SOON?

WE'RE STILL RUNNING TESTS AT MOUNT VESUVIUS AND IN POZZUOLI

THAT MIGHT HELP US ANSWER THAT QUESTION,

BUT WE NEED TO MONITOR THIS SUPERVOLCANO

FOR A FEW MORE DAYS.

SO IN THE MEANTIME, WE'RE MAKING THE TREK

TO THE MOTHER OF ALL ITALIAN VOLCANOES,

SICILY'S MOUNT ETNA,

WHERE A TEAM OF SCIENTISTS ARE USING CUTTING-EDGE ROBOTICS

TO REVOLUTIONIZE THE WAY WE MONITOR VOLCANOES.

LAVA FLOW RIGHT IN FRONT OF US.

GEOLOGISTS FEAR A RECENT STRING OF ERUPTIONS HERE

COULD BE THE OMINOUS PRELUDE OF A MUCH BIGGER BANG.

I DID NOT THINK THIS VOLCANO WOULD BE THIS BIG, STEFAN.

LIKE, I THOUGHT WE WOULD BE TO THE TOP FAIRLY QUICKLY.

IT JUST KEEPS GOING.

WELL, IT'S TWO AND A HALF TIMES THE HEIGHT OF VESUVIUS,

AND THAT'S A TALL VOLCANO.

THEY'VE BEEN DOCUMENTING THIS VOLCANO

ALL THE WAY BACK TO VIRGIL.

YEAH, THE ROMANS KEPT TRACK OF ALL THESE THINGS,

AND VERY FEW OF THESE OTHER VOLCANOES

HAVE THIS HUMAN-RECORDED HISTORY.

ETNA IS KNOWN IN ARABIC AS THE MOUNTAIN OF FIRE,

AND IT HAS BEEN CONSISTENTLY ACTIVE

FOR THE PAST HALF MILLION YEARS,

KILLING 15,000 PEOPLE

DURING IT'S MOST VIOLENT ERUPTION IN 1669.

THESE DAYS, ETNA SEEMS TO BE GETTING MORE ACTIVE AGAIN.

SINCE 1998, THE CONE OF THE SOUTHEAST CRATER

HAS GROWN BY 300 FEET, AND JUST LAST YEAR,

A NEWS CREW WAS CAUGHT IN AN UNEXPECTED ERUPTION ON ETNA.

THEY RAN FOR THEIR LIVES AS BOILING HOT ROCKS

RAINED DOWN FROM THE SKY.

CLEARLY, MOUNT ETNA IS STILL A MAJOR THREAT

TO EVERYONE AND EVERYTHING AROUND IT.

SICILY AND NAPLES ARE SITUATED ALONG THE SAME FAULT LINE

BETWEEN THE AFRICAN PLATE TO THE SOUTH

AND THE EURASIAN PLATE TO THE NORTH.

SO VOLCANIC ACTIVITY IN ONE AREA

COULD SIGNAL INCREASING DANGER IN THE OTHER,

WHICH IS WHY STEFAN AND I ARE ANXIOUS TO SEE IT UP CLOSE.

HAVEN'T BEEN ON A GONDOLA IN A WHILE.

WE'RE HEADING TO AN AREA JUST BELOW THE SUMMIT TO MEET UP

WITH A TEAM OF ROBOTICS ENGINEERS

WHO ARE CONDUCTING GROUNDBREAKING SURVEYS

AT MOUNT ETNA.

WE'RE ACTUALLY GOING TO A PLACE THAT TOURISTS

ARE NOT ALLOWED TO GO,

SO THERE IS A LITTLE BIT OF EXTRA DANGER

BECAUSE WE'RE KIND OF GOING ABOVE AND BEYOND...

CLOSER, YEAH....THE SAFE LEVEL,

AND IT'S TOTALLY FORBIDDEN TO GO TO THE TOP.

IS IT? YEAH.

END OF THE ROAD.

YEAH?

YEAH.

OUR FIRST UP-CLOSE GLIMPSE OF MOUNT ETNA

IS BREATHTAKING.

THE RUGGED TERRAIN, EXTREME WIND,

AND DARK, EXPANSIVE ASH EXTEND AS FAR AS THE EYE CAN SEE.

IT MAKES YOU WONDER IF THIS IS WHAT

POMPEII WOULD HAVE LOOKED LIKE AFTER MOUNT VESUVIUS

FINISHED SPEWING A SEA OF ASH AND MUD ONTO THE CITY.

IN FACT, POMPEII WAS BURIED SO DEEP UNDERGROUND

THAT IT WAS LOST FOR OVER 1,500 YEARS.

BUT THERE WERE SOME PEOPLE WHO MANAGED TO LIVE

TO TELL THE TALE.

WITH THE FUTURE OF ITALY, EUROPE,

AND BEYOND HANGING IN THE BALANCE,

WE NEED TO ENSURE MORE PEOPLE MAKE IT TO SAFETY

IF CAMPI FLEGREI'S SUPERVOLCANO BLOWS.

THIS PUTS THE WHOLE THING IN PERSPECTIVE, YOU KNOW?

THIS IS THE MOST ACTIVE VOLCANO RIGHT NOW IN ALL OF EUROPE.

YEAH.

BUT THE ONLY HOPE OF SURVIVING

A MASSIVE DISASTER LIKE THIS

IS BEING ABLE TO PREDICT IT AHEAD OF TIME.

THAT'S SOMETHING RESEARCHERS ARE WORKING HARD TO DO BETTER,

AND NOW THEY'VE GOT ROBOTS ON THE CASE.

CAN THIS LITTLE DROID SAVE THE WORLD?

IS ITALY AND ALL OF EUROPE LIVING ON BORROWED TIME?

WE'RE ON TOP OF MOUNT ETNA

INVESTIGATING INCREASED GEOTHERMAL ACTIVITY UNDER ITALY,

AND MEETING WITH A TEAM OF SCIENTISTS

WHO ARE WORKING ON A NEW PROJECT

THEY CALL ROBOTIC EXPLORATION OF EXTREME ENVIRONMENTS,

OR ROBEX.

AIR IS PRETTY THIN UP HERE.

ROBEX DEVELOPS NEW WAYS

TO EXPLORE HIGHLY INACCESSIBLE TERRAIN

LIKE MOUNT ETNA,

AND ONE DAY SOON, MAYBE EVEN THE MOON AND OTHER PLANETS.

TODAY, WE'RE GETTING AN EXCLUSIVE SNEAK PEAK

AS THEY TEST OUT A BRAND-NEW,

STATE-OF-THE-ART, LIGHTWEIGHT ROVER UNIT

ENGINEERED TO GO WHERE HUMANS CAN'T.

CHECK IT OUT, IT'S RIGHT THERE.

THIS IS SO COOL.

THE ROBEX ROVER CAN WITHSTAND THE HARSHEST OF CLIMATES,

ENABLING IT TO PLACE AND RETRIEVE SEISMOMETERS

NEAR LAVA FLOWS AND INSIDE FUMAROLES.

IT'S MAPPING THE AREA WITH TWO STEREO CAMERAS.

SO IT'S DRIVING AUTONOMOUSLY RIGHT NOW.

YEAH, ABSOLUTELY, YEAH.THAT'S AMAZING. VERY COOL.

KIND OF SHUFFLES IT IN?

YEAH, I WAS CURIOUS ABOUT THAT.

THIS IS SUPER COOL.

WOW, LOOK AT THAT.

THIS IS THE FUTURE OF SEISMOLOGY RIGHT HERE.

YEAH.

GEOPHYSICIST FRANK SOHL

IS A KEY MEMBER OF THE ROBEX TEAM.

CAN YOU TELL US A LITTLE BIT ABOUT WHAT'S GOING ON HERE?

TEN PERCENT?Burns: FOR THE WORLD?

YES, FOR THE WORLD... WOW.

DOCTOR SOHL HOPES THAT ONCE THE ROBEX ROVER

EARNS IT'S STRIPES ON ETNA,

IT WILL BE ADOPTED IN VOLCANIC HOT SPOTS

AROUND THE WORLD AS A NEW WEAPON IN THE BATTLE

TO PROTECT MANKIND FROM MOTHER NATURE.

PREDICTING WHEN A VOLCANIC ERUPTION HAPPENS IS DIFFICULT.

ARE WE GETTING CLOSER, THOUGH?

THE IDEA OF FIGHTING VOLCANOES WITH ROBOTS IS TOTALLY FAR OUT,

BUT WE'VE GOT SOME GADGETS OF OUR OWN ON THE CASE TOO,

AND IT'S TIME WE SEE WHAT THEY HAVE TO TELL US.

ALL RIGHT. LET'S HEAD TO NAPLES.

I'M HUNGRY FOR SOME PIZZA.

ME, TOO.

THE NEXT DAY, BACK IN NAPLES,

STEFAN AND I COLLECT OUR SEISMOMETER

FROM THE TOP OF VESUVIUS

AND THE G.P.S. ANTENNA FROM THE MARKETPLACE AT POZZUOLI.

NOW IT'S TIME TO SEE WHETHER CAMPI FLEGREI

IS GEARING UP TO EXPLODE.

ALL RIGHT. SO, WHAT DO WE HAVE, STEFAN?

SO, ACCORDING TO THE DATA FROM VESUVIUS,

WE JUST RECORDED ORDINARY MICROTREMORS

FOR A VOLCANO.REALLY?

IT LOOKS LIKE THERE HAVE BEEN A TON OF MICROTREMORS

SINCE WE'VE BEEN HERE, BUT BELIEVE IT OR NOT,

THAT'S PAR FOR FOR THE COURSE AROUND NAPLES.

IT HAPPENS ALL THE TIME.

SO THERE'S NOTHING IN THE SEISMOMETER READINGS

THAT SUGGEST THIS IS THE WEEK THE VOLCANIC WINTER ARRIVES,

AT LEAST THROUGH MOUNT VESUVIUS.

NOW WITH THE G.P.S. ANTENNA AT POZZUOLI,

WE JUST GOT SOME DATA WHICH IS EXTRAORDINARY.

NOW THIS IS LESS COMFORTING.

WITH THE HELP OF A NUMBER OF SATELLITES,

WE USED A G.P.S. UNIT TO TRACK GROUND MOVEMENT.

AND IN JUST ONE WEEK, WE'VE CAUGHT EVIDENCE

OF AN UPLIFT IN THE EARTH'S CRUST.

OUR FINDINGS ARE CONFIRMED BY ANOTHER RECENT STUDY.

THE OVERALL REGION HAS EXPERIENCED AN UPLIFT

OF OVER 3 INCHES IN THE PAST FEW MONTHS.

INCHES? YEAH, 3 INCHES

DOESN'T SOUND LIKE MUCH, YOU KNOW, IT'S JUST THIS.

BUT IF IT CONTINUES AT THIS RATE,

WE'LL SEE A RISE OF 10 FEET IN JUST 10 YEARS.

THAT'S THE AVERAGE HEIGHT OF A ONE-STORY HOUSE,

WHICH IS MIND-BLOWING.

THE GROUND IS LITERALLY RISING UP BELOW OUR FEET

DUE TO MAGMA CHAMBERS FILLING AND SWELLING BELOW US.

THAT'S INCREDIBLE.

THIS DISCOVERY COMBINED WITH THE BUBBLING FUMAROLES AT BAIA,

THE OMINOUS HOT WATER IN THE TUNNEL TO HELL,

AND THE DRAMATIC TEMPERATURE RISE AT SOLFATARA

ARE ALL CRITICAL CLUES THAT SUGGEST THIS SUPERVOLCANO

IS GETTING SET TO UNLEASH CARNAGE ON A TERRIFYING SCALE.

THIS IS REALLY INCREDIBLE,

AND I FEEL LIKE WE'RE SEEING GEOLOGIC HISTORY

BEING WRITTEN RIGHT IN FRONT OF US.

IN A NIGHTMARE SCENARIO, THE DEATH AND DESTRUCTION

UNLEASHED ON THOSE LIVING IN THE SHADOW OF CAMPI FLEGREI

COULD BE MUCH WORSE THAN WHAT WAS SEEN IN POMPEII.

WHETHER ITALY WILL FALL VICTIM TO MORE DEADLY EARTHQUAKES

OR AN EVEN DEADLIER VOLCANIC ERUPTION

IS STILL ANYBODY'S GUESS.

BUT WHAT ISN'T IN DOUBT IS THAT MILLIONS OF LIVES ARE AT RISK,

WHICH IS WHY SEISMIC TECHNOLOGIES

LIKE THE ROBEX ROVER WE SAW ON MOUNT ETNA

ARE KEY TO UNDERSTANDING MORE ABOUT HOW VOLCANOES WORK

AND WHEN THEY WILL ERUPT.

WE'LL NEVER BE ABLE TO PREVENT A CATACLYSMIC ERUPTION,

BUT HOPEFULLY, ONE DAY, WE'LL AT LEAST BE ABLE TO PREDICT ONE

WITH ENOUGH LEAD TIME TO GET PEOPLE OUT OF HARM'S WAY.

FOR NOW, THE WORLD WILL HAVE TO WAIT AND HOPE

THAT THE CAMPI FLEGREI SUPERVOLCANO

STAYS QUIET,

AND THAT THEY STORY OF POMPEII

DOESN'T HAVE AN EVEN MORE CATASTROPHIC SEQUEL.