Original subtitles

female narrator: ITALY.

IT'S A PLACE THAT MEANS SO MUCH TO SO MANY.

THE ART,

THE CULTURE,

THE BEACHES,

THE MOUNTAINS.

ITALY IS A SKINNY BOOT

THRUST INTO THE BLUE OF THE SPARKLING MEDITERRANEAN

WITH THE ISLAND OF SICILY

LIKE A BALL BALANCING AT ITS TOE.

BUT ITALY HASN'T ALWAYS LOOKED LIKE THIS.

IT IS A TURBULENT LAND GEOLOGICALLY

AND HAS CHANGED TREMENDOUSLY OVER TIME.

SINCE THE DAYS OF LEONARDO DA VINCI,

SCIENTISTS HAVE STRUGGLED TO LEARN

WHAT MAKES THIS LAND SO DRAMATIC,

SO UNUSUAL,

SO VIOLENT.

[siren wailing]

THIS IS THE LAND THAT GAVE BIRTH TO THE SCIENCE OF GEOLOGY

IN THE 17TH CENTURY.

EVER SINCE THEN,

GEOLOGIC DISCOVERIES MADE IN ITALY

HAVE ROCKED OUR THINKING ABOUT OUR PLANET.

- [speaks Italian]

narrator: IT'S A SUNNY DAY IN EARLY SPRING.

- [speaking Italian]

narrator: AMERICAN GEOMORPHOLOGIST

FRANK PAZZAGLIA IS WORKING ON THE MUSONE RIVER

IN THE APENNINE MOUNTAINS.

WITH HIM IS AN ITALIAN STUDENT, SANDRO MARIANI.

- [speaking Italian]

- [speaking Italian]

- SI, SI. PERFECTO.

narrator: THE GRANDSON OF ITALIAN IMMIGRANTS TO THE U.S.,

FRANK IS INTRIGUED

BY THE COMPLEXITIES OF ITALIAN GEOLOGY.

HE'S WORKING IN ITALY AS PART

OF AN INTERNATIONAL TEAM OF EARTH SCIENTISTS,

HOPING TO ADD SOME NEW PAGES

TO ITALY'S FASCINATING, UNFINISHED GEOLOGIC TALE.

SPECIFICALLY, THEY WOULD LIKE TO ANSWER A QUESTION

THAT HAS BEEN NAGGING AT GEOLOGISTS FOR YEARS.

ARE THE APENNINES STILL GROWING,

OR ARE PARTS OF THEM NO LONGER ACTIVE?

- THERE IS AN OPINION AMONG MANY GEOSCIENTISTS

THAT THE FRONT OF THE APENNINES ARE DEAD,

THAT THEY ARE NO LONGER GROWING TECTONICALLY.

NOW THIS IS NOT SHARED BY ALL GEOLOGISTS.

SO WE'VE DEFINED FOR OURSELVES HERE

A VERY AMBITIOUS PROJECT TRYING TO UNDERSTAND

THE GROWTH AND THE EVOLUTION OF THE APENNINE MOUNTAINS.

AND IN DOING THIS AND TRYING

TO UNDERSTAND THIS PARTICULAR MOUNTAIN RANGE,

WE HOPE TO BE ABLE TO SAY SOMETHING MORE GENERAL

ABOUT HOW MOUNTAINS ARE BUILT THROUGHOUT THE WORLD

AND HOW THE LESSONS THAT WE LEARNED HERE TIE IN

TO THE GENERAL THEORY OF PLATE TECTONICS

AND THE CONSTRUCTION OF GREAT MOUNTAIN RANGES.

narrator: THE GROUNDWORK FOR UNDERSTANDING ITALY'S MOUNTAINS

HAD ALREADY BEEN LAID CENTURIES AGO

BY SCIENTIFIC PIONEERS.

IT WAS HERE IN THE APENNINES DURING THE RENAISSANCE

THAT LEONARDO DA VINCI AND LATER, NICOLAUS STENO,

STUDIED FOSSILIZED SEA SHELLS.

THEY REALIZED THAT THESE WERE THE KEY

TO UNDERSTANDING THE GROWTH OF THESE MOUNTAINS.

THE WORD "GEOLOGY" ITSELF WAS INVENTED IN ITALY

IN 1603 BY ULISSE ALDROVANDI.

FOR FRANK PAZZAGLIA AND HIS PREDECESSORS,

ITALY IS A MOST REWARDING PLACE TO STUDY MOUNTAINS.

SOME 75% OF THE LAND IS MOUNTAINOUS.

IN THE NORTH ARE THE HIGHEST MOUNTAINS,

THE ITALIAN ALPS.

HEADING SOUTH, THE APENNINES FORM THE BACKBONE OF ITALY.

THEY RUN DOWN THE ENTIRE LENGTH OF THE PENINSULA

AND INTO NORTHERN SICILY.

WHERE THE MOUNTAINS REACH TO THE COAST,

LIMESTONE CLIFFS RISE STEEPLY FROM THE SEA.

THE COLORFUL TOWNS OF CINQUE TERRE

IN NORTHERN ITALY

ARE STACKED AMONG THESE CLIFFS.

THE APENNINES MEET THE SEA AGAIN IN SOUTHERN ITALY,

MAKING FOR STUNNING SCENERY ON THE AMALFI COAST.

FROM SICILY TO THE ALPS,

ITALY'S MOUNTAINS ARE A STEADY PRESENCE,

AND FOR THE MOST PART,

IT'S OBVIOUS TO GEOLOGISTS THAT THE BULK OF THE MOUNTAINS

ARE ACTIVELY GROWING.

IN FACT, IN SOME PLACES,

AS FRANK PAZZAGLIA AND HIS COLLEAGUES WELL KNOW,

THEY ARE GROWING UNUSUALLY QUICKLY.

ONE OF THE FASTEST-RISING MOUNTAIN RANGES

IS CLOSE TO A CITY KNOWN ALL AROUND THE WORLD

FOR ITS LEANING TOWER, WHICH DATES FROM 1173.

PISA IS ALSO A VIBRANT CENTER OF LEARNING

AND HAS BEEN FOR HUNDREDS OF YEARS.

JUST DOWN THE ROAD FROM THE LEANING TOWER,

GIANCARLO MOLLI IS A GEOLOGY PROFESSOR

AT THE UNIVERSITY OF PISA,

WHERE GALILEO TAUGHT IN THE 16TH CENTURY.

TODAY GIANCARLO AND HIS STUDENTS ARE DISCUSSING

THE NEARBY MOUNTAINS THAT ARE RISING SO QUICKLY.

THEY ARE CALLED THE ALPI APUANE.

- [speaking Italian]

narrator: MUCH OF THE GEOLOGIC STORY

OF THE ALPI APUANE HAS BEEN PIECED TOGETHER

BY ITALIAN GEOLOGISTS OVER THE YEARS.

- [speaking Italian]

narrator: BUT GIANCARLO IS DETERMINED

TO FILL IN THE BLANKS.

MYSTERIES REMAIN AS TO HOW FAST THESE MOUNTAINS HAVE RISEN.

GIANCARLO WANTS TO KNOW EXACTLY HOW FAST AND WHY.

THESE ARE THE MOUNTAINS THAT BROUGHT UP FROM THE DEPTHS

A VERY RARE AND EXCEEDINGLY BEAUTIFUL ROCK.

THAT ROCK IS THE FAMOUS ITALIAN MARBLE

SHAPED CENTURIES AGO

BY THE SCULPTORS OF THE RENAISSANCE.

IN FLORENCE,

MARBLE ADORNS THE ORNATE CAMPANILE AND DUOMO.

IT WAS HERE IN FLORENCE THAT MICHELANGELO BUONARROTI

BROUGHT TO LIFE HIS UNFORGETTABLE STATUE

OF THE YOUNG DAVID.

THE DAVID STANDS NEXT TO UNFINISHED SCULPTURES

KNOWN AS THE PRISONERS.

THEY ARE STILL STRUGGLING TO COME OUT OF THE ROCK.

MICHELANGELO'S SUBLIME SCULPTURES

ALSO GUARD THE TOMBS OF THE POWERFUL MEDICI FAMILY.

HE FOUND THE PURE MARBLE THAT HE NEEDED FOR HIS WORK

IN THE ALPI APUANE MOUNTAINS NEAR THE TOWN OF CARRARA.

THE ALPI APUANE ARE SO NAMED

FOR THEIR CRAGGY, ALPINE-LOOKING PEAKS.

THEIR DAZZLING WHITENESS CAN EASILY BE MISTAKEN

FOR SNOW FROM A DISTANCE.

BUT THE WHITE IS NOT SNOW.

IT'S MARBLE.

ALL OVER THESE MOUNTAINS ARE QUARRIES,

WHERE HUGE CHUNKS OF MARBLE HAVE BEEN EXTRACTED.

THESE QUARRIES REMAIN

THE WORLD'S LARGEST PRODUCER OF MARBLE.

- [speaking Italian]

narrator: FOR GEOLOGISTS LIKE GIANCARLO MOLLI,

A QUARRY CAN BE AN EXCELLENT PLACE

TO STUDY THE INSIDES OF MOUNTAINS.

THE ROCK LAYERS HAVE BEEN EXPOSED,

MAKING IT EASIER TO TELL HOW THEY'VE BEEN LAID DOWN,

SQUASHED, AND FOLDED.

THE HARD MARBLES WERE CREATED FROM SOFTER LIMESTONE.

IT WAS IN THE LIMESTONE HILLS OF TUSCANY AROUND FLORENCE

THAT LEONARDO DA VINCI FOUND FOSSILIZED SEASHELLS.

THIS WAS IN THE EARLY 1500s,

RIGHT AT THE TIME MICHELANGELO

WAS LABORING OVER HIS SCULPTURES.

WHEN LEONARDO FOUND THE SEASHELLS,

IT WAS NOT UNDERSTOOD HOW THEY HAD GOTTEN OUT OF THE SEA

AND INTO THE MOUNTAINS.

BUT OVER THE YEARS,

SCIENTISTS DEVELOPED AN IMPRESSIVE EXPLANATION.

MILLIONS OF YEARS AGO, THERE WAS NO ITALY HERE.

INSTEAD, THERE WAS A SHALLOW OCEAN

CALLED THE TETHYS.

- THE GEOLOGIC STORY OF ITALY IS REALLY FASCINATING

BECAUSE YOU HAVE TO GO BACK TO SET THE STAGE.

BEFORE THERE WAS ANYTHING THAT WE WOULD RECOGNIZE

AS THE APENNINE MOUNTAINS,

THERE WAS THE SEPARATION OR THE BREAKUP

OF A LARGE SUPERCONTINENT CALLED PANGAEA.

AND IN THE BREAKUP OF THIS CONTINENT,

A NEW OCEAN BASIN WAS CREATED.

WE CALL THIS OCEAN BASIN TETHYS.

narrator: TINY SEA CREATURES LIVED

IN THE ANCIENT TETHYS OCEAN.

OVER TIME, AS THEY LIVED AND THEN DIED,

THEIR REMAINS DRIFTED TO THE OCEAN FLOOR.

THESE DEPOSITS BUILT UP LAYERS OF SEDIMENT MILES THICK

AT THE BOTTOM OF THIS SEA.

EVENTUALLY, THE LAYERS HARDENED INTO LIMESTONE.

IN THE CASE OF THE CARRARA MARBLES,

THE LIMESTONE WAS THEN BURIED DEEPLY

BY TECTONIC FORCES OVER MILLIONS OF YEARS.

EXTREME HEAT AND PRESSURE BAKED IT INTO MARBLE.

- THIS CUT OF MARBLE IS SPECIAL, A PURE WHITE MARBLE.

THAT IS A--THAT IS THE REASON WHY IT WAS USED BY THE ROMAN

AND THEN DURING RENAISSANCE, FOR EXAMPLE BY MICHELANGELO,

UP TO NOW FOR MONUMENTS

AS WELL AS FOR BUILDING STONE.

AND THE FACT THAT IT IS SO PURE IS DUE TO THE FACT

THAT THE ORIGINAL SEDIMENT OF THE ENVIRONMENT WAS SPECIAL.

narrator: THAT SPECIAL ENVIRONMENT WAS

A WARM, CALM, SHALLOW OCEAN,

SOMETHING LIKE THE CARIBBEAN SEA OF TODAY.

BUT TO PRODUCE MARBLE THAT IS SO PURE AND WHITE,

THE ORIGINAL SEA FLOOR

HAD TO BE WELL AWAY FROM BEACHES AND SAND.

BUT HOW DID ITALY'S LIMESTONES, FORMED IN THE SEA,

END UP AS RUGGED MOUNTAINS,

RISING FAR ABOVE SEA LEVEL TODAY?

THIS QUESTION PUZZLED GEOLOGISTS FOR CENTURIES.

THE PLACE WHERE THE PUZZLE FINALLY BEGAN TO FIT TOGETHER

WAS IN ONE OF THE WORLD'S GREAT MOUNTAIN RANGES,

THE ALPS.

A PARTICULARLY DRAMATIC PART OF THIS MAJESTIC RANGE

GUARDS ITALY'S NORTHERNMOST BORDER.

PIECING TOGETHER THE STORY OF THE ALPS

WAS EXTREMELY DIFFICULT

PARTLY BECAUSE OF THE VERTICAL TERRAIN

AND PARTLY BECAUSE THE ROCKS OF THE ALPS SEEMED ALL WRONG.

THEY WERE TOPSY-TURVY.

IT WASN'T UNTIL THE 1960s

AND THE ADVENT OF THE THEORY OF PLATE TECTONICS

THAT THE ALPS BEGAN TO MAKE SENSE.

ABOUT 80 MILLION YEARS AGO,

GLOBAL TECTONIC FORCES CAUSED

THE CONTINENTS OF AFRICA AND EUROPE

TO APPROACH EACH OTHER.

IN BETWEEN THEM, THE SEA FLOOR OF THE TETHYS,

INCLUDING A SPECIAL PIECE OF CRUST, OR MICROPLATE,

CALLED ADRIA,

DOVE OR SUBDUCTED BENEATH EUROPE.

AS THIS HAPPENED,

GREAT SLABS OF THE EARTH'S CRUST

AND SEDIMENTS FROM THE SEA FLOOR

WERE PILED UP INTO MOUNTAINS

AT THE EDGE OF THE EUROPEAN CONTINENT.

IN SOME PLACES,

OLDER ROCKS WERE SHOVED OVER YOUNGER ONES,

OBSCURING THEIR ORIGINS.

GEOLOGISTS CLIMBING HIGH IN THE MOUNTAINS

EVEN FOUND A PIECE OF THE EARTH'S MANTLE,

WHICH IS NORMALLY BURIED

20 MILES BENEATH THE EARTH'S CRUST.

THE ALPS WERE A GEOLOGICAL MESS, BUT A BEAUTIFUL ONE.

AND FROM THE UNRAVELING OF THIS MESS,

GEOLOGISTS ANSWERED THE QUESTION OF HOW SEASHELL FOSSILS

COULD END UP IN MOUNTAINS.

WHEN THE CONTINENTS COLLIDED,

ANCIENT LIMESTONES FROM THE TETHYS OCEAN

WERE THRUST HIGH IN THE AIR.

ONE OF THE MOST DRAMATIC EXAMPLES OF THIS ACTION

CAN BE SEEN IN ITALY'S DOLOMITES.

HERE, HUGE LAYERS OF LIMESTONE,

ONCE RESTING FAR BELOW THE SURFACE OF THE SEA,

ARE NOW STANDING AT GREAT HEIGHTS

DRAPED IN HIGH MOUNTAIN GLACIERS.

GLACIERS ALSO CARVED OUT SPECTACULAR LAKES,

LIKE LAKE COMO DURING THE ICE AGES.

ARMED WITH THE STORY

OF THE CATACLYSMIC BIRTH OF THE ALPS,

GEOLOGISTS BEGAN TO EXPLORE WHETHER THIS FANTASTIC TALE

COULD ALSO EXPLAIN THE BIRTH

OF ITALY'S OTHER GREAT MOUNTAIN RANGE,

THE APENNINES.

WERE THESE ALSO PUSHED UP BY COLLIDING PLATES?

THE STORY FIT IN MANY PLACES,

BUT IN SOME, IT DIDN'T.

THE ALPI APUANE RANGE

WAS ONE OF THOSE PLACES WHERE IT DIDN'T.

GEOLOGISTS COULD SEE THAT SOMETHING FAR DIFFERENT

MUST HAVE MADE THESE MOUNTAINS.

BUT WHAT WAS IT?

IT WASN'T UNTIL MANY YEARS LATER

THAT THIS MYSTERY WOULD BE SOLVED.

THERE WAS ANOTHER PLACE IN ITALY

THAT LOOKED VERY STRANGE TO GEOLOGISTS.

IN THE MOUNTAINS OF CALABRIA AT THE TOE OF THE BOOT,

STRUCTURAL GEOLOGIST NANO SEEBER IS EXPLORING

HOW THIS GEOLOGICALLY PERPLEXING AREA CAME TO BE.

ON THE MAP, CALABRIA FORMS A LINK

BETWEEN THE APENNINES

AND THE MOUNTAINS TO THE SOUTH IN SICILY.

BUT THE APENNINES AND THE MOUNTAINS OF SICILY

ARE MOSTLY COMPOSED OF LIMESTONE AND OTHER SEDIMENTARY ROCKS.

IN CONTRAST, CALABRIA'S MOUNTAINS ARE MADE

OF GRANITE AND METAMORPHIC ROCK,

TOTALLY DIFFERENT FROM LIMESTONE.

OVER THE YEARS, ITALIAN GEOLOGISTS PUZZLED

OVER THE STRANGE ROCKS OF CALABRIA,

MUCH AS NANO SEEBER IS DOING TODAY.

- IN GEOLOGY, THAT'S WHAT YOU NEED TO DO.

YOU NEED TO LOOK AT A MOUNTAIN AND THINK OF WHAT'S IN IT.

AND NOT ONLY THAT, BUT THINK HOW IT CHANGES

THE SHAPE OF THE ROCKS INSIDE THE MOUNTAIN.

narrator: IT SOON BECAME APPARENT TO ITALIAN GEOLOGISTS

THAT THE ODD ROCKS OF CALABRIA EXTENDED INTO SICILY.

- IT'S CONTROLLED BY THIS FORCE.

narrator: THERE WAS A PART OF SICILY,

THE NORTHEASTERN CORNER,

THAT WAS VERY DIFFERENT FROM THE REST OF THE ISLAND.

HERE AT MESSINA,

THE ROCKS ARE MORE LIKE CALABRIA'S ROCKS

AND NOTHING LIKE THE REST OF THE APENNINES.

CLOSE BY, THE SICILIAN COASTAL RESORT OF TAORMINA

IS ALSO BUILT ON ROCKS LIKE CALABRIA'S.

THE ROCKS OF THE REST OF SICILY

FIT WITH THE APENNINES ON THE MAINLAND.

WHAT COULD EXPLAIN THESE DIFFERENCES?

IT TOOK A NEW TWIST TO THE THEORY OF PLATE TECTONICS

FOR GEOLOGISTS TO FIGURE OUT WHERE THESE ROCKS HAD COME FROM.

AND WITH THAT TWIST

CAME A DRAMATIC NEW UNDERSTANDING

OF ALL OF ITALY.

IT TURNS OUT THAT THE ROCKS OF CALABRIA AND NORTHERN SICILY

STRONGLY RESEMBLED THOSE OF THE ALPS.

AND IN FACT, AS FRANK PAZZAGLIA LEARNED

FROM HIS ITALIAN COLLEAGUES,

THESE ROCKS HAD ONCE BEEN PART OF FRANCE.

- ITALY AT ONE TIME WAS ACTUALLY CONNECTED TO FRANCE.

AND OVER THE PAST SEVERAL TENS OF MILLIONS OF YEARS,

IT HAS BEEN SWINGING TO THE EAST.

narrator: CHUNKS OF ROCK THAT WOULD BECOME ITALY

ALONG WITH CORSICA AND SARDINIA

SEPARATED FROM FRANCE ABOUT 30 MILLION YEARS AGO.

ITALY, STILL UNDERWATER,

PLOWED INTO THE ADRIA MICROPLATE,

WHICH SUBDUCTED BENEATH IT.

IN THE PROCESS, PIECES OF ADRIA WERE SCRAPED OFF

AND A NEW MOUNTAIN RANGE BEGAN TO GROW.

THE APENNINES WERE BORN.

INITIALLY THE MOUNTAINS WERE BELOW SEA LEVEL.

FINALLY, BETWEEN 5 AND 10 MILLION YEARS AGO,

ITALY EMERGED FROM THE SEA.

THE SUBDUCTION PROCESS CAUSED A GROWING WEDGE OF MATERIAL

THAT RAN DOWN THE WHOLE LENGTH OF THE ITALIAN PENINSULA.

- SO ITALY LOOKS LIKE A BOOT

POSITIONED TO KICK TO THE WEST,

BUT IN FACT, IT IS MOVING BACK TOWARDS THE EAST

SWINGING AND CONSUMING THE ADRIA MICROPLATE

IN ITS WAKE.

narrator: THE SWINGING ITALIAN BOOT THAT EMERGED FROM THE SEA

SOLVES LEONARDO DA VINCI'S MYSTERY

ABOUT HOW THE FOSSILIZED SEASHELLS

GOT INTO THE APENNINES.

BUT THIS FASCINATING TALE

OF THE BIRTH OF ITALY AND THE APENNINES

WAS NOT YET THE WHOLE STORY.

THERE WERE SOME VERY FAMOUS MOUNTAINS IN THE SOUTH

THAT DID NOT FIT THIS PICTURE AT ALL.

OR DID THEY?

IN SOUTHERN ITALY

ABOVE THE FAST-MOVING FOOT OF THE ITALIAN BOOT

LOOMS THE LEGENDARY MOUNT VESUVIUS.

MOUNT VESUVIUS IS THE ONLY ACTIVE VOLCANO

ON MAINLAND EUROPE.

PEOPLE COME TO SEE IT FROM ALL OVER THE WORLD.

DURING RECORDED HISTORY,

VESUVIUS HAS BEEN KNOWN TO ERUPT HUNDREDS OF TIMES.

THE MOST FAMOUS ERUPTION

BURIED THE PROSPEROUS ROMAN TRADING CITY,

POMPEII, IN 79 A.D.

VESUVIUS IS STILL ACTIVE AND COULD ERUPT AT ANY TIME.

FARTHER SOUTH ON SICILY, AT THE TOE OF THE BOOT,

IS THE MASSIVE MOUNT ETNA.

LIKE MOUNT VESUVIUS,

ETNA IS A VERY ACTIVE AND FAMOUSLY DESTRUCTIVE VOLCANO.

FOR YEARS, GEOLOGISTS COULD NOT EXPLAIN

WHAT THE TWO VOLCANOES WERE DOING HERE.

BUT AROUND THE TIME PLATE TECTONICS THEORY

WAS ESTABLISHED IN THE 1960s,

GEOLOGISTS CAME TO A SURPRISING CONCLUSION

ABOUT MOUNT VESUVIUS AND MOUNT ETNA.

THEY ARE VOLCANOES AND COMPLETELY DIFFERENT

FROM THE APENNINES OR THE ALPS.

BUT THEY ARE ACTUALLY CAUSED BY THE SAME PROCESS,

SUBDUCTION.

AS THE SUBDUCTING PLATE SINKS DOWN,

IT SLIDES UNDER THE OTHER AND HEATS UP.

THIS HEATED MATERIAL BECOMES MAGMA,

WHICH RISES UP THROUGH THE TOP PLATE

TO BUILD ACTIVE VOLCANOES.

THE ITALIAN VOLCANOES FIT THIS PICTURE WELL.

IN FACT, GEOLOGISTS COULD TRACE A VOLCANIC ARC

THAT FOLLOWS THE SUBDUCTING PLATE.

STARTING AROUND ROME,

WHERE THERE ARE SOME DORMANT VOLCANOES,

AND CURVING DOWN PAST STROMBOLI

AND THE VOLCANIC AEOLIAN ISLANDS

AND CONTINUING PAST ETNA FARTHER SOUTH.

BUT THERE WAS SOMETHING PECULIAR ABOUT ETNA.

[all speaking Italian]

ON A BRIGHT JUNE MORNING,

NANO SEEBER AND GRADUATE STUDENT MARGARET REITZ

HAVE COME DOWN FROM CALABRIA

TO GET TO THE BOTTOM OF THIS PECULIAR FEATURE.

- [speaking Italian]

- YEAH, THERE ARE-- THERE ARE A NUMBER OF FAULTS.

ACTUALLY WE'VE GOT A NORTH, NORTHEAST TREND

FROM THE STRAIT OF MESSINA.

narrator: ETNA'S ERUPTIONS CONTAIN

A RARELY SEEN MIXTURE OF LAVA AND ASH.

USUALLY, A VOLCANO PRODUCES ONE OR THE OTHER.

WHY DOES ETNA PRODUCE BOTH?

NANO AND MEG HAVE A NEW TECHNIQUE FOR FINDING OUT,

BUT THEY MOST GET THE PERFECT LAVA SAMPLE.

THEY HAVE TO WORK FAST.

THE VOLCANO HAS BEEN ERUPTING FREQUENTLY,

AND THE SCIENTISTS ARE SEIZING THIS RARE OPPORTUNITY

TO FIND A SAMPLE BEFORE IT ERUPTS AGAIN.

THE GOING IS DIFFICULT AND EVEN DANGEROUS.

LEADING THE WAY IS BORIS BEHNCKE OF THE I.N.G.V.,

ITALY'S NATIONAL INSTITUTE OF GEOPHYSICS AND VULCANOLOGY.

- A PART OF THIS VENT ERUPTED ON THE TENTH OF MAY.

narrator: BORIS KNOWS ETNA AS WELL AS ANYONE ALIVE.

- THE MOUNTAIN IS QUITE A LARGE VOLCANO

AND ALSO ONE OF THE MOST ACTIVE VOLCANOES ON EARTH.

IT'S CURRENTLY 3,330 METERS TALL.

THAT'S A LITTLE BIT LESS THAN 11,000 FEET.

IT'S ONE OF THE MOST ACTIVE VOLCANOES ON EARTH,

MAYBE THE SECOND MOST ACTIVE AFTER KILAUEA ON HAWAII.

- IT'S ONE OF THE MOST ACTIVE VOLCANOES

ON THE PLANET.

AND IT'S VERY YOUNG, ACTUALLY.

IT'S ONLY HALF A MILLION YEARS OLD.

narrator: HOW IT GOT SO BIG SO FAST

IS PART OF THE RIDDLE OF ETNA.

HOW DID SO MUCH LAVA ACCUMULATE SO QUICKLY?

- ETNA SITS IN A PLACE WHERE THERE ARE LOTS OF FAULTS

AND CRACKS RUNNING THROUGH THE CRUST OF THIS PLANET.

IN THIS VERY AREA,

MANY OF THESE FAULT SYSTEMS INTERSECT IN THAT PLACE.

SO IT'S A PLACE OF PARTICULAR INSTABILITY,

AND THUS IT IS MUCH EASIER

FOR THE MAGMA TO COME IN THAT PLACE.

THERE SEEMS TO BE NO OTHER VOLCANOES ON EARTH

WHERE WE HAVE A SIMILAR GEODYNAMIC SITUATION.

- THAT LOOKS GOOD.

BEAUTIFUL.

- NOW WE CAN BREAK THAT DOWN FURTHER.

- YEAH, YEAH.

narrator: FINALLY THE TEAM FINDS THE PERFECT SAMPLE.

- YUP.

THERE. - IT'S HARD ROCK.

narrator: THEY WILL TAKE IT TO THE LAB FOR ANALYSIS

AND FIND OUT THAT, INDEED, ETNA'S LAVA IS HIGHLY UNUSUAL.

IT OFTEN COMES FROM VERY DEEP IN THE EARTH,

WORKING ITS WAY UP THROUGH CRACKS.

NANO'S TEAM TIME THEIR EXPEDITION PERFECTLY.

SHORTLY AFTER THEIR CLIMB, ETNA EXPLODED.

IT'S BECAUSE ETNA IS SO ACTIVE

THAT A HUGE NETWORK OF SEISMIC STATIONS,

GAS-MONITORING DEVICES,

AND OTHER HIGH-TECH MONITORING INSTRUMENTS

HAS BEEN SET UP TO WARN OF IMPENDING ERUPTIONS.

THIS WARNING SYSTEM,

ONE OF THE WORLD'S MOST ADVANCED,

KEEPS THE MILLION PEOPLE LIVING CLOSE BY SAFER.

THERE ARE SO MANY PEOPLE LIVING HERE BECAUSE,

AS IT TURNS OUT,

THERE ARE MULTIPLE ADVANTAGES TO LIVING ON A VOLCANO.

- THERE ARE LOTS OF BENEFITS TO LIFE ON A VOLCANO

BECAUSE WE'VE GOT VERY FERTILE SOILS

DUE TO THE WEALTH OF MINERALS IN THE VOLCANIC PRODUCT,

ESPECIALLY IN THE ASH.

AND EVERYTHING THAT GROWS ON ETNA

IS A LITTLE BIT BIGGER AND A LITTLE BIT MORE TASTY.

THERE ARE IMPORTANT RESOURCES LIKE TOURISM.

THEN THE VOLCANO PROVIDES BUILDING MATERIAL

BECAUSE LAVA IS VERY RESISTANT ROCK,

MUCH BETTER THAN CONCRETE.

AND FINALLY, ALSO,

THE VOLCANO STORES INCREDIBLE QUANTITIES OF WATER

BECAUSE IT'S ALL POROUS ROCK,

AND THAT IS CERTAINLY AN IMPORTANT ELEMENT

IN A PLACE LIKE SICILY

WHERE THERE ARE ELSEWHERE PROBLEMS WITH DROUGHT.

IF THE SOUTHEAST QUAKE ERUPTS AGAIN,

IT'LL THROW OUT A LOT OF OLD MATERIAL.

narrator: AS THESE SCIENTISTS LEARN MORE

ABOUT MOUNT ETNA AND VOLCANOES,

THEY'RE ALSO GETTING INSIGHTS

INTO AN INTIMATELY RELATED GEOLOGIC PROCESS

ALSO CAUSED BY PLATE MOVEMENTS AND SUBDUCTION:

EARTHQUAKES.

PEOPLE HERE HAVE NOT FORGOTTEN

THE MASSIVE MESSINA EARTHQUAKE OF 1908,

WHICH CAUSED WIDESPREAD DESTRUCTION

IN BOTH SICILY AND CALABRIA.

- THERE'S BEEN TERRIBLE EARTHQUAKES

IN THIS PART OF THE WORLD.

AND UNDERSTANDING HOW CALABRIA WORKS TECTONICALLY

IS GONNA HELP TO UNDERSTAND

WHAT KIND OF EARTHQUAKES WE CAN EXPECT.

narrator: THE PEOPLE OF CALABRIA AND THE REST OF SOUTHERN ITALY

ARE WELL AWARE THAT EARTHQUAKES AND VOLCANOES

ARE THE GEOLOGIC SIGNATURES OF THEIR LAND.

BOTH ARE DRIVEN BY THE CRUSHING TECTONIC FORCE OF SUBDUCTION.

BUT IS SUBDUCTION AT WORK FARTHER TO THE NORTH?

IS IT A MAJOR FORCE THERE?

- ENTIRE BLOCKS OF BUILDINGS COLLAPSED

AS A POWERFUL EARTHQUAKE STRUCK CENTRAL ITALY

IN THE MIDDLE OF THE NIGHT.

U.S. GEOLOGICAL SURVEY SAYS

THE QUAKE MEASURED 6.3 ON THE RICHTER SCALE.

narrator: IN 2009, A LARGE EARTHQUAKE

STRUCK THE CENTRAL ITALIAN TOWN OF L'AQUILA,

KILLING MORE THAN 300 PEOPLE.

ABOUT 100 MILES AWAY IN THE REGION OF UMBRIA,

THE 13TH CENTURY BASILICA OF ST. FRANCIS OF ASSISI

WAS SEVERELY DAMAGED

AND FOUR PEOPLE PERISHED

WHEN AN EARTHQUAKE STRUCK IN 1997.

OBVIOUSLY THE EARTH'S CRUST IS VERY ACTIVE IN CENTRAL ITALY.

REGIONS LIKE UMBRIA AND TUSCANY

ARE FREQUENTLY JOLTED BY EARTHQUAKES.

BUT UNLIKE THE SOUTH, CENTRAL ITALY HAS NO VOLCANOES.

THE LINE OF SUBDUCTION-DRIVEN VOLCANOES ENDS NORTH OF ROME.

IS A PROCESS OTHER THAN SUBDUCTION

BUILDING THE MOUNTAINS

AND TRIGGERING THE EARTHQUAKES IN CENTRAL ITALY?

UNTIL RECENTLY, GEOLOGISTS THOUGHT THAT SUBDUCTION

WAS LONG DEAD TO THE NORTH OF ROME.

APPARENTLY, ANOTHER PROCESS,

THE STRETCHING OF THE EARTH'S CRUST,

HAD TAKEN OVER--

OR SO THEY THOUGHT.

BUT EARTH SCIENTISTS WORKING IN CENTRAL AND NORTHERN ITALY

HAVE BEGUN TO WONDER.

ONE OF THEM IS MARK BRANDON,

AN OLD FRIEND AND ADVISOR OF FRANK PAZZAGLIA.

THEY ARE MEETING IN THE MEDIEVAL TOWN OF ELCITO,

FROM WHICH THEY CAN SEE A LONG WAY OFF.

- SO WE'RE LOOKING ALONG THE ENTIRE ADRIATIC COAST HERE.

- EXACTLY, WE'RE LOOKING OUT OVER THE TOP OF CINGOLI RIDGE,

AND FROM CINGOLI RIDGE,

THERE'S ONLY ONE MORE LIMESTONE RIDGE.

narrator: MARK HAS BEEN TRAVELING AROUND TUSCANY,

WHERE SIGNS OF THE STRETCHING OF THE EARTH'S CRUST

ARE MUCH IN EVIDENCE TO GEOLOGISTS.

- WE SEE THE ROCKS AT THE SURFACE PULLING APART.

AND A GOOD EXAMPLE OF THAT IS THAT IF WE GO

INTO VARIOUS PARTS OF THE LANDSCAPE

LIKE AROUND FLORENCE,

WHAT WE SEE ARE THERE ARE BIG GRABENS OR STRETCH MARKS

WHERE THE EARTH IS PULLING APART AT THE SURFACE.

IN FACT, MANY OF THE EARTHQUAKES WE SEE

ARE DUE TO A LARGE PART OF THE CRUST AT THE SURFACE

BEING STRETCHED APART.

narrator: THE LOVELY LANDSCAPE OF TUSCANY NEAR FLORENCE

IS A FAMILIAR ONE,

OFTEN USED AS THE BACKGROUND IN RENAISSANCE PAINTINGS.

ONLY A CLOSER LOOK BY GEOLOGISTS REVEALS THE WRENCHING APART

OF THIS GENTLE LANDSCAPE.

- SO, I MEAN, WE THINK MASSA COULD GO UNDER HERE.

narrator: TRAVELING ONWARD FROM CENTRAL ITALY

AND HEADING TO THE NORTHWEST,

MARK BRANDON AND HIS COLLEAGUE DARRYL COWEN

CAN TELL THAT MUCH MORE THAN STRETCHING

IS OPERATING TO BUILD ITALY'S MOUNTAINS.

ONE PLACE WHERE THEY'RE HOPING TO FIND THE MISSING LINK

IS IN MICHELANGELO'S MARBLE QUARRIES

IN THE ALPI APUANE MOUNTAINS.

WAITING FOR HIS AMERICAN COLLEAGUES

AT THE STATION IN CARRARA

IS GIANCARLO MOLLI WITH STUDENT GABRIEL CAZALLI.

- HOW ARE YOU? - CIAO.

narrator: GIANCARLO IS TAKING THE GROUP

TO HIS RUGGED, MOUNTAINOUS FIELD AREA.

GEOLOGISTS HAVE WORKED OUT THAT THE FAMOUS MARBLES HERE

HAVE RISEN UP VERY QUICKLY FROM DEEP IN THE EARTH.

AND THE ONLY WAY THEY COULD'VE RISEN UP SO RAPIDLY

IS IF THE ROCKS AROUND THEM WERE BEING STRETCHED APART

BY A VERY POWERFUL AND MYSTERIOUS FORCE.

THAT STRETCHING WOULD HAVE OPENED A GAP FOR THE ALPI APUANE

TO RISE QUICKLY TO THE SURFACE.

- THE ALPI APUANE EXPOSES THE DEEPEST METAMORPHIC ROCKS

IN THE APENNINES.

WHAT WE MEAN BY THIS,

THESE ARE ROCKS THAT HAVE BEEN TAKEN DEEP INTO THE CRUST

AND HAVE BEEN TRANSFORMED

BY HIGH TEMPERATURES AND HIGH PRESSURES

INTO ENTIRELY NEW ROCKS.

AND FOR MANY YEARS NOW,

THERE'S BEEN THE RECOGNITION THAT THE APUANE AREA

AND THE METAMORPHIC ROCKS THAT UNDERLIE IT

HAVE BEEN BROUGHT UP TO THE SURFACE

BY THIS OVERALL STRETCHING PROCESS.

SO IT'S A MANIFESTATION OF THIS EXTENSION OR STRETCHING PROCESS,

THE DEEPEST OR MOST PRONOUNCED MANIFESTATION OF THAT.

narrator: WITH THE FAMOUS MARBLES

OF THE ALPI APUANE FRESH IN HIS MIND,

MARK IS IMPRESSED

BY WHAT THE STRETCHING OF THE EARTH'S CRUST CAN DO.

BUT WHAT IS THE FORCE BEHIND THE RAPID STRETCHING APART

OF TONS OF ROCK IN THE ALPI APUANE?

AND WHY IS IT THAT THE EARTH'S CRUST IN ITALY

IS BEING PULLED APART IN SOME AREAS

WHILE AT THE SAME TIME,

IT'S BEING SQUEEZED UP IN OTHER AREAS?

FORTUNATELY, MARK HAS STUDIED MOUNTAIN BELTS AROUND THE WORLD,

AND ONE THEORY HAS EMERGED THAT MAKES SENSE TO HIM.

IT'S CALLED ROLLBACK.

IN THIS SCENARIO,

THE APENNINES ARE BEING SQUEEZED UP INTO MOUNTAINS

ABOVE THE DOWN-GOING SUBDUCTING PLATE.

MEANWHILE, THE SUBDUCTING PLATE DRAWS BACKWARD

AT THE POINT WHERE IT CURVES DOWNWARD.

THIS IS CALLED ROLLBACK OF THE PLATE.

AS IT ROLLS BACK,

THE SUBDUCTING PLATE

SUCKS THE COLLIDING PLATE TOWARDS IT,

STRETCHING IT APART.

ON TOP OF THAT PLATE,

THE CRUST ALSO STRETCHES AND DEFORMS,

RISING UP IN SOME PLACES AND SINKING DOWN IN OTHERS,

CREATING A LANDSCAPE OF HILLS AND VALLEYS,

AS IN TUSCANY.

BUT ROLLBACK HAS BEEN HARD TO PROVE,

AND THERE ARE OTHER THEORIES THAT MIGHT EXPLAIN

THE OBSERVATIONS ON THE SURFACE.

THIS DEBATE IS WHAT HAS BROUGHT MARK BRANDON TO ITALY.

- ITALY IS AN EXCEPTIONAL PLACE

TO STUDY THIS PROCESS OF COLLISION OF PLATES

AND OVERALL STRETCHING AT THE SURFACE.

WE SEE THIS GOING ON IN DIFFERENT MOUNTAIN BELTS,

SUCH AS THE HIMALAYA, THE ANDES.

WE ALSO SEE IT GOING ON IN SUBMARINE SUBDUCTION ZONES,

LIKE THE MARIANA IN THE WESTERN PACIFIC.

BUT MANY OF THOSE SETTINGS,

EITHER THE PROCESS HAS BEEN ARRESTED

OR IT'S DIFFICULT TO STUDY DIRECTLY

BECAUSE THE TOPOGRAPHY IS TOO HIGH

OR WE CAN'T GET DIRECTLY TO THOSE AREAS.

narrator: THE ACCESSIBLE TOPOGRAPHY

OF ITALY'S APENNINES WITH ITS NETWORK OF GOOD ROADS

OFFERS ONE OF THE BEST HOPES

OF SOLVING THIS IMPORTANT GEOLOGIC MYSTERY.

GEOLOGISTS GENERALLY AGREE THAT THE COLLISION OF THE PLATES

FOLLOWED BY THE SUBDUCTION OF THE ADRIA MICROPLATE

PUSHED UP THE APENNINES SOME 5 TO 10 MILLION YEARS AGO.

BUT IN ONE PART OF THE APENNINES AROUND THE CITY OF BOLOGNA,

MANY GEOLOGISTS WERE CLAIMING

THAT THE MOUNTAINS WERE NOW DEAD;

THEY WERE NO LONGER BEING PUSHED UP BY SUBDUCTION.

IF THAT WERE TRUE, THEN THE ROLLBACK THEORY,

WHICH HINGED IN PART

ON SUBDUCTION STILL BEING ACTIVE IN NORTHERN ITALY,

WAS ALSO DEAD.

- 40,000 OR SOMETHING.

AND RIGHT HERE IT SAYS THAT--

- HEY, HEY, WHAT'S GOING ON?

- WELL, SHE'S GOT THESE REALLY,

REALLY INTERESTING OFFSETS IN THE TERRACES.

- YOU GUYS ARE WORRYING TOO MUCH ABOUT THE GEOLOGY.

TODAY'S--TODAY'S THE FEAST OF SAN GIUSEPPE

AND IT'S VERY--IT'S TRADITIONAL IN MANY PARTS OF ITALY

TO HAVE BREADS MADE ON THE FEAST OF SAN GIUSEPPE.

- BELLISSIMA.

- FESTE DEL PAPA.

AND THIS IS A SERPENTONI.

WE STUFFED IT WITH APPLES.

AND THIS IS JUST A REGULAR BRAID BREAD.

- DID YOU MAKE THAT TOO?

narrator: FRANK AND MARK HAVE ENLISTED EXPERTS

FROM VARIOUS FIELDS OF EARTH SCIENCE

TO FIND OUT IF THE APENNINES ARE STILL ALIVE OR NOT.

- WE'RE DIPPING TOWARDS THE BASE...

narrator: THIS IS PERHAPS THE BIGGEST GEOLOGICAL MYSTERY

REMAINING IN ITALY

AND SOLVING IT WILL NOT BE EASY.

THE SCIENTISTS ARE MEETING TO STRATEGIZE

AT THE GEOLOGIC OBSERVATORY OF COLDIOGIOCO,

A TINY VILLAGE IN THE NORTHERN APENNINES.

A NUMBER OF THE SCIENTISTS ARE CONDUCTING EXPERIMENTS

AT THE EARTH'S SURFACE

TO DETERMINE IF IT'S LIFTING UP AND DEFORMING.

OTHERS ARE IMAGING THE DEEP INTERIOR OF THE EARTH.

STILL OTHERS ARE MAPPING THE BENDS AND TURNS

IN ROCK LAYERS BROUGHT UP FROM FAR BELOW.

- THAT IS THE PROBLEM WITH THE...

narrator: ONE MEMBER OF THE COLLABORATION

IS GEOLOGIST VINCENZO PICOTTI.

VINCENZO HAS BEEN WORKING ON THE RENO RIVER

AT A TOWN CALLED MARZABOTTO, NOT FAR FROM BOLOGNA.

HERE A NOVEL TECHNIQUE HAS BEEN USED

TO CALCULATE THE AGES OF THE TERRACES ABOVE THE RIVER.

ON TOP OF THESE TERRACES

ARE ARTIFACTS OF THE ANCIENT ETRUSCANS

THAT ONCE LIVED HERE.

ON ONE WIDE, FLAT RIVER TERRACE

ARE THE RUINS OF AN ANCIENT ETRUSCAN TOWN.

SINCE ARCHAEOLOGISTS KNOW EXACTLY

WHEN THE ETRUSCANS LIVED ON THIS TERRACE,

VINCENZO CAN USE THAT DATE TO ESTABLISH

THAT THE RIVER TERRACE IS AT LEAST THAT OLD.

THIS WILL HELP HIM SEE

IF THE MOUNTAINS ARE STILL GROWING.

- THIS IS A VILLAGE OF ETRUSCAN AGE.

AND THOSE WALLS WE CAN SEE NOW

ARE THE FOUNDATIONS OF THE HOUSES

OF THIS HIGHLY-CIVILIZED PEOPLE.

THE AGE OF THIS VILLAGE

IS MORE OR LESS 2,500 YEARS.

AND SO WE CAN HAVE A MINIMUM AGE

FOR THE RIVER TERRACE.

narrator: SOIL GEOMORPHOLOGIST MISSY EPPES

IS USING A DIFFERENT TECHNIQUE.

SHE IS ESTABLISHING THE AGES OF RIVER TERRACES

THAT MAY BE HUNDREDS OF THOUSANDS OF YEARS OLD

BY LOOKING AT THE SOIL ON TOP OF THEM.

- SOILS WORK MUCH LIKE PEOPLE WORK

IN TERMS OF THE OLDER THEY GET,

THEY HAVE CERTAIN CHARACTERISTICS

THAT ENABLE YOU TO UNDERSTAND HOW OLD THEY ARE,

JUST LIKE A MOM MIGHT BE ABLE TO LOOK AT ANY CHILD

AND KNOW THAT IT'S, YOU KNOW, 15 WEEKS OR A YEAR AND A HALF,

OR, YOU KNOW, THREE YEARS,

AND YOU USE THE CHARACTERISTICS OF THAT CHILD

TO SAY HOW OLD IT IS.

WE DO THE SAME THING WITH SOILS.

THE OLDER SOILS GET, THE REDDER THEY GET,

THE DEEPER THEY GET, THE MORE CLAY THEY HAVE IN THEM.

WELL, ACTUALLY, I MEAN--

SO THAT I CAN GO UP TO AN OUTCROP

AND LOOK AT A NICE EXPOSURE OF A SOIL AND SAY,

"YOU KNOW, THIS MUCH REDDENING, THIS MUCH CLAY,

"IT MUST BE 10,000 YEARS OLD.

"THIS SOIL IS REALLY THICK. IT HAS A LOT OF CLAY.

IT MUST BE 100,000 YEARS OLD."

THIS IS WHERE I WAS HAVING ALL THAT TROUBLE.

IF THIS WERE THE QT-6 DRAFT, THEN THEY'RE BE A LOT OF OFFSET.

SO IF WE COULD FIND A SOIL RIGHT THERE,

THEN WE WOULD REALLY KNOW.

ONCE MISSY AND GRADUATE STUDENT RYAN BEERMA

FIND AGES FOR THE RIVER TERRACES,

THEY CAN LOOK TO SEE IF THERE ARE TERRACES OF THE SAME AGE

BUT OF DIFFERENT ELEVATIONS.

IF THEY FIND THOSE MISMATCHED TERRACES,

IT MEANS THE EARTH'S SURFACE IS DEFORMING HERE.

OR IN OTHER WORDS, THE APENNINES ARE STILL ALIVE AND GROWING.

- YEAH, YEAH, YEAH. - OKAY, WOW.

narrator: MEANWHILE, THE SCIENTISTS HAVE FOUND

YET ANOTHER WAY TO LEARN FROM THE RIVERS

IF THE MOUNTAINS ARE RISING OR ARE NOW DEAD.

- ONE VERY CRITICAL DATA SET THAT WE ARE COLLECTING

IS RELATED TO THE RATE AT WHICH RIVERS

ARE CARVING THEIR VALLEYS

AND VERTICALLY INCISING INTO THE APENNINES.

BECAUSE THE RATE THAT RIVERS INCISE INTO MOUNTAINS

IS RELATED TO THE RATE THAT THE ROCKS ARE COMING UP.

narrator: THAT IS, IF THEY ARE COMING UP.

WHILE FRANK IS WORKING ON UNDERSTANDING VERTICAL MOTIONS,

ELSEWHERE HORIZONTAL MOTIONS ARE BEING MEASURED.

IN THE TINY INDEPENDENT REPUBLIC OF SAN MARINO,

SCIENTISTS ARE MEASURING HOW THE EARTH'S TECTONIC PLATES

ARE MOVING IN NORTHERN ITALY.

- YOU CAN'T BE AFRAID OF HEIGHTS AND RUN THIS NETWORK.

- NO.

narrator: HERE GEODESIST RICK BENNETT

AND HIS ITALIAN COLLEAGUES

HAVE INSTALLED ONE OF THEIR GPS ANTENNAS.

- IN THIS PROJECT, WE'RE INSTALLING ANTENNAS,

SUCH AS THIS ONE,

IN AS MANY LOCATIONS AS WE CAN FIND

THROUGHOUT NORTHERN ITALY.

THE IDEA IS THAT WE'LL BE ABLE TO DETERMINE

THE MOTION OF ALL OF THESE INSTRUMENTS.

AND FROM THAT INFORMATION WE'LL BE ABLE TO LEARN

ABOUT HOW THE ITALIAN PENINSULA

IS RESPONDING TO THE RELATIVE MOTION

BETWEEN THE AFRICA PLATE, THE EURASIA PLATE,

AND THE ADRIATIC PLATE.

narrator: IN THE COURSE OF A YEAR OR TWO,

THE GPS ANTENNAS SHOULD DETECT MOVEMENT,

EVEN A TINY MOVEMENT,

IF THE MOUNTAINS OF NORTHERN ITALY

ARE STILL GROWING AND PULLING APART.

IT MAY EVEN BE POSSIBLE TO TELL IF THE ENTIRE PENINSULA,

THE BOOT, IS STILL SWINGING BACK,

GETTING READY TO KICK.

- SHALL WE TRY? - TRY, YEAH, SURE.

- JUST TAKE UP.

narrator: BUT IT'S NOT ALWAYS EASY TO FIND THE BEST SPOT

TO INSTALL THESE ANTENNAS.

FORTUNATELY FOR THIS ONE,

A COLLEAGUE HAS VOLUNTEERED HIS ROOF.

- SURVEY ANTENNA, SEE?

- IT'S BEEN VERY DIFFICULT TO FIND GOOD LOCATIONS

TO PUT THESE INSTRUMENTS.

THEY REQUIRE SKY VISIBILITY

SO THAT THEY CAN ACTUALLY SEE THE SATELLITES.

THEY REQUIRE SOLID BEDROCK SO THAT WE CAN BE CONFIDENT

THAT THEY'RE FIRMLY ATTACHED TO THE EARTH'S SURFACE.

AND THERE ARE NOT MANY PLACES IN NORTHERN ITALY

WITH THOSE CHARACTERISTICS.

SO WE'VE HAD TO RESORT TO SOME RATHER UNCONVENTIONAL WAYS

OF ATTACHING THE ANTENNAS TO THE EARTH.

IN SOME INSTANCES,

WE'VE ACTUALLY PUT THE ANTENNAS ON ANCIENT CASTLES

THAT HAVE BEEN AROUND FOR 800 YEARS OR SO

WHICH ARE NOW POSSIBLY PART OF THE EARTH'S SURFACE.

narrator: ALL OF THESE GEOLOGIC STUDIES

GENERATE HUGE AMOUNTS OF DATA.

MOST OF IT IS A PILE OF NUMBERS

HIDDEN IN COMPUTERS AND NEVER SEEN,

EVEN BY THE SCIENTISTS WORKING ON THEM.

BUT THAT DATA WILL FORM

THE BASIS OF IMPORTANT NEW SCIENTIFIC DISCOVERIES

AND OCCASIONALLY SOMETHING ELSE:

MUSIC.

[both speaking Italian]

AT COLDIOGIOCO, SANDRO MONTANARI,

THE DIRECTOR OF THE GEOLOGICAL OBSERVATORY,

HAS BUILT A RECORDING STUDIO

WITH THE HELP OF COMPOSER GABRIELE ROSSETTI.

THE TWO COLLEAGUES ARE TAKING GEOLOGIC DATA

AND TURNING THEM INTO NOTES AND MUSIC.

ONE OF THEIR COMPOSITIONS IS BASED ON DATA

FROM A WORLD-SHATTERING EVENT DISCOVERED IN SOME ROCKS

NOT FAR FROM COLDIOGIOCO.

HERE A THIN LAYER IN THE ROCKS GAVE SCIENTISTS THE FIRST CLUE

THAT IT WAS A GIANT METEOR STRIKING THE EARTH

THAT SPELLED THE END FOR THE DINOSAURS.

[both speaking Italian]

TODAY SANDRO AND GABRIELE ARE WORKING ON ANOTHER PIECE

CALLED GOCCE DE TEMPO, DROPS OF TIME.

- THIS IS OUR PLOTS OF CARBON AND OXYGEN ISOTOPES.

THEY'RE BEING TAKEN FROM THE FRASASSI GORGE.

AND THE VARIATION OF THESE VALUES

TELL US HOW THE ENVIRONMENT WAS CHANGING THROUGH TIME

FOR THE PAST 100,000 YEARS.

narrator: THIS MUSIC REFLECTS THE CHEMISTRY OF FORMATIONS

IN A SERIES OF MAGNIFICENT CAVES,

THE FRASASSI CAVES.

THESE CAVES ARE MADE OF LIMESTONE

WHICH WAS BORN 100 MILLION YEARS AGO

IN THE TETHYS OCEAN.

TINY DROPS OF WATER HAVE DISSOLVED AWAY THE LIMESTONE

TO SCULPT MORE THAN 100 CAVES AT FRASASSI.

BESIDES BEING A WONDERFUL SOURCE OF MUSICAL COMPOSITION,

THE FRASASSI CAVES HOLD IMPORTANT GEOLOGICAL CLUES

ABOUT THE GROWTH OF THE APENNINES.

SANDRO MARIANI,

WHO'S BEEN WORKING WITH FRANK PAZZAGLIA

AT THE MUSONE RIVER,

IS AN ACCOMPLISHED CAVE EXPLORER.

HIS NICKNAME IS SPIDERMAN.

SANDRO IS USING A LEVELING INSTRUMENT

TO SEE IF THE ROCK LAYERS IN THE CAVE HAVE BEEN TILTED.

TILTING WOULD MEAN THAT THE ROCKS WERE BENT

AS THE MOUNTAINS GREW.

AND SURE ENOUGH, SANDRO FINDS BENT ROCKS IN THE CAVES.

THIS IS EVIDENCE THAT THE MOUNTAINS

HAVE BEEN SLOWLY GROWING THROUGH THE EONS.

GOING DEEPER STILL,

SCIENTISTS ARE INTERESTED IN KNOWING WHAT'S HAPPENING

FAR BELOW THE EARTH'S SURFACE.

TO SEE MANY MILES DOWN INTO THE EARTH,

SEISMOLOGIST SILVIA PONDRELLI AND JEFFREY PARK

ARE INSTALLING SEISMIC INSTRUMENTS IN THE MOUNTAINS.

- I THINK THAT SEISMOLOGY IS GOING TO BE PIVOTAL

IN DETERMINING THE BEST EXPLANATION

FOR THE NORTHERN APENNINES

BECAUSE IT'S SEISMOLOGY THAT ALLOWS US

TO SEE BENEATH THE SURFACE, BENEATH THE CRUST,

AND INTO THE MANTLE WHERE THE ACTION IS.

narrator: THEIR BIGGEST QUESTION IS THIS:

IS THE ADRIA MICROPLATE STILL SUBDUCTING,

CAUSING THE APENNINES TO GROW?

OR ARE OTHER PROCESSES INVOLVED

IN BUILDING THE APENNINES?

JEFF AND SILVIA WILL USE WAVES GENERATED BY EARTHQUAKES

TO SEE IF THEY CAN FIND THE ANSWER

IN THE DEEPEST ROOTS OF THE MOUNTAINS.

WHILE SILVIA, JEFF, AND THEIR COLLEAGUES

WORK TO FIND OUT WHETHER NORTHERN ITALY

IS STILL ALIVE GEOLOGICALLY,

IN THE SOUTH THERE IS NO DOUBT.

STRIKING EVIDENCE FOR THIS IS FOUND AT THE ADRIATIC COAST

IN AN AREA CALLED APULIA.

HERE AT THE HEEL OF THE ITALIAN BOOT,

INSTEAD OF MOUNTAINS,

THERE IS A MOSTLY FLAT LEVEL COASTLINE.

SEASIDE RESORT TOWNS LIKE TRANI

LINE THE LONG CURVING BAYS OF THE COAST

AND LOOK OUT UPON THE GENTLE WAVES

OF THE ADRIATIC SEA.

DOTTING THE COUNTRYSIDE

ARE ROUND STONE HUTS CALLED TRULLI.

THERE IS A CONCENTRATION OF TRULLI

IN THE TOWN OF ALBEROBELLO,

A UNESCO WORLD HERITAGE SITE.

THESE WHITEWASHED HUTS ARE BUILT OF LIMESTONE,

WHICH FORMS THE BEDROCK OF THIS UNUSUAL PART OF ITALY.

LIMESTONE HAS BEEN MORE

THAN THE STUFF OF BUILDING BLOCKS IN APULIA.

IN THE TOWN OF MATERA,

PEOPLE ONCE ACTUALLY LIVED INSIDE THE LIMESTONE,

CARVING THEIR DWELLINGS

INTO THE LIMESTONE CLIFFS RUNNING BELOW THE CITY.

THESE DWELLINGS, DATING FROM MEDIEVAL TIMES,

ARE KNOWN AS SASSI.

BUT WHY IS APULIA SO DIFFERENT FROM MOUNTAINOUS CALABRIA?

IT TURNS OUT THAT IN THE COMPLEX GEOLOGY

OF SOUTHERN ITALY,

APULIA IS YET ANOTHER MICROPLATE

THAT WAS ONCE A PART OF AFRICA.

- ABOUT 10 MILLION YEARS AGO,

CALABRIA AND SARDINIA WERE TOGETHER,

AND CALABRIA DECIDED TO GO ALONE,

SO IT TOOK OFF FROM SARDINIA AND MOVED SOUTHEAST.

AND IN DOING SO, IT CREATED THE TYRRHENIAN SEA

AND COLLIDED WITH AN OLD PIECE OF AFRICA

WHICH IS CALLED APULIA.

narrator: ORIGINALLY APULIA WAS UNDER THE SEA,

A GENTLE SEA FLOOR MADE OF LIMESTONE.

IT WAS PUSHED UP ABOVE SEA LEVEL

BY ITS COLLISION WITH CALABRIA.

APULIA AND CALABRIA SIT ON OPPOSITE SIDES

OF THE GREAT SUBDUCTION ZONE THAT CREATED ITALY

WHERE THE AFRICAN AND EUROPEAN PLATES COLLIDE.

THE COLLISION ZONE SWEEPS RIGHT THROUGH THE HEART OF SICILY.

- SEE THERE, ANOTHER VOLCANIC...

narrator: MARK BRANDON AND HIS COLLEAGUE KARL WEGMANN

HAVE COME DOWN TO SICILY TO SEE IF THE SUBDUCTION ZONE HERE

CAN TELL THEM SOMETHING ABOUT SUBDUCTION IN THE NORTH.

THEY ARE GUIDED BY ONE OF THE LEADERS

OF SICILIAN GEOLOGY, FABIO LENTINI.

- INTERESTING. - YOU SEE HERE.

- YEAH. - OH, LOOK AT THOSE CORALS.

- THESE ARE COLONIAL CORALS.

[speaks Italian]

narrator: THEY START THEIR RECONNAISSANCE

IN NORTHERN SICILY.

THIS PART OF THE ISLAND IS DEFINED BY MOUNTAINS.

THEY HUG THE COAST AND PROTECT ANCIENT CITIES

LIKE CEFALU AND THE SICILIAN CAPITAL PALERMO,

ONCE THE GREATEST CITY IN EUROPE.

THE GEOLOGISTS STOP FREQUENTLY TO STUDY THE LIMESTONE MOUNTAINS

PUSHED UP BY THE POWER OF SUBDUCTION.

AS MARK AND HIS COLLEAGUES REACH CENTRAL SICILY,

THE MOUNTAINS THIN OUT,

BECOMING ISOLATED SKY ISLANDS TOPPED BY TOWNS

LIKE ENNA AND IT'S MEDIEVAL RIVAL ACROSS THE VALLEY,

CALASCIBETTA.

- I DON'T, UH-- ENNA IS THE PLACE.

narrator: A LITTLE FURTHER SOUTH,

THE LANDSCAPE FLATTENS SUDDENLY.

THIS IS THE AFRICAN PLATE,

AND HALF OF SICILY SITS ON THIS PLATE.

THE SOILS AND BEDROCK OF SOUTHERN SICILY

ARE BEST SEEN ALONG ITS BREATHTAKING COAST.

THEY COME IN SHADES OF WHITE.

RAGGED LIMESTONE TERRACES MAKE

FOR COZY ALCOVES AND SECRET HARBORS.

THIS ONE, NORTH OF SYRACUSE, WAS ONCE A PIRATE HANGOUT.

SALT AND GYPSUM MINES ARE EVERYWHERE.

THESE MINERALS SPEAK OF A REMARKABLE TIME

ABOUT 6 MILLION YEARS AGO

WHEN TECTONIC FORCES BLOCKED THE STRAIT OF GIBRALTAR.

THE ANCIENT MEDITERRANEAN SEA

WAS CUT OFF FROM THE WATERS OF THE ATLANTIC,

LEADING TO WHAT GEOLOGISTS CALLED

THE MESSINIAN SALINITY CRISIS.

- THE WHOLE MEDITERRANEAN DRIED UP.

IT WAS A BIG DEEP HOLE WHERE WE NOW HAVE WATER.

AND AS IT DRIED UP,

ALL OF THE SALT AND OTHER DISSOLVED CONSTITUENTS

CAME OUT AS THICK, EVAPORITE UNITS.

narrator: THE DEPOSITS PILED UP ON THE DRIED-OUT SEABED.

LATER, OCEAN WATER FLOODED BACK IN AGAIN

AND COVERED THEM UP.

NOW AS THE AFRICAN AND EUROPEAN PLATES CONTINUE TO COLLIDE,

THOSE SEABED DEPOSITS ARE SLOWLY RISING OUT OF THE SEA.

FARTHER SOUTH,

AT THE SOUTHERNMOST PART OF SICILY,

STAND THE SPECTACULAR GREEK TEMPLES

OF AGRIGENTO.

NEAR AGRIGENTO, THE COASTAL ROCKS CLEARLY SHOW

THE EFFECTS OF THE INCOMING AFRICAN PLATE.

THERE IS NO DOUBT THAT THIS PART OF ITALY

IS GEOLOGICALLY ALIVE AND KICKING.

- YOU CAN SEE THE OCEAN OUT TO THE SOUTH OF US,

AND FURTHER ON IS AFRICA-- IN FACT, TUNISIA.

AND IN THIS AREA, WE'RE LOOKING AT

THE VERY BEGINNING OF THE COLLISION

BETWEEN ITALY AND AFRICA.

AND IN THIS COLLISION ZONE,

THERE ARE A BUNCH OF ROCKS THAT ARE CRUMPLED UP.

YOU CAN SEE THEM FOLDED IN THE BACKGROUND OVER HERE.

AND THEY REPRESENT MARINE SEDIMENTS IN PART

THAT WERE ORIGINALLY IN THE OCEAN TO THE SOUTH OF US

AND HAVE BEEN SQUISHED

AS ITALY HAS COME COLLIDING WITH AFRICA.

narrator: TUNISIA IS CLOSE TO SICILY,

ONLY 60 MILES AWAY.

SO MARK AND KARL HAVE COME DOWN TO EXPLORE THE COLLISION ZONE

FROM THE AFRICAN SIDE.

TUNISIAN GEOLOGIST SAMI KHOMSI TAKES THEM ON A TOUR

OF THE MOUNTAINOUS COUNTRYSIDE.

GEOLOGISTS HAVE WORKED OUT THAT THESE ROCKS IN NORTHERN TUNISIA

ARE ACTUALLY AN EXTENSION OF THE APENNINES.

THEY WERE CREATED BY THE SAME SUBDUCTION ZONE

THAT CREATED ITALY.

THE SUBDUCTION ZONE CURVES DOWN FROM SICILY

TO BUNCH UP THE ATLAS MOUNTAINS IN TUNISIA.

THE ROCKS HERE ANNOUNCE THE COLLISION SITUATION

LOUD AND CLEAR.

THEY ARE TIGHTLY FOLDED AND BROKEN UP IN MANY PLACES.

BUT IN NORTHERN ITALY, IN FRANK PAZZAGLIA'S FIELD AREA,

THERE ARE NO SUCH OBVIOUS CLUES.

[both speaking Italian]

SO SCIENTISTS ARE PATIENTLY PLYING THEIR TRADE,

GATHERING DATA.

- BRIAN, IF YOU NEED A HAND GETTING THAT--THAT...

narrator: FINALLY A BREAKTHROUGH COMES NEAR BOLOGNA.

- THEY'RE ALL FASTENED DOWN THERE.

narrator: IT COMES UNEXPECTEDLY FROM THE DETAILED MAPPING

OF THE RIVER TERRACES AND THE SOILS ON TOP OF THEM.

THE SCIENTISTS FIND FAULTS

CAUSED BY EARTH MOVEMENTS BREAKING UP THE TERRACES.

FINDING FRESH, ACTIVE FAULTS HELPS PROVE THAT THE APENNINES

ARE INDEED STILL ALIVE AND GROWING.

FRANK'S NAGGING QUESTION HAS BEEN ANSWERED.

- IT'S DOWNSTREAM, ACTUALLY STRATIFIED...

- A VERY EXCITING RESULT

THAT'S EMERGING FROM OUR COLLABORATION

IS THAT IN FACT THE MOUNTAIN FRONT AT BOLOGNA

IS TECTONICALLY ACTIVE AND IS CONTINUING TO GROW.

- OH, LOOKIT THERE.

- THE DATA ARE VERY COMPELLING,

AND WE'RE VERY EXCITED BY THIS CONCLUSION.

narrator: OTHER RESULTS TAKE A FEW YEARS LONGER.

ROCK SAMPLES FROM THE ALPI APUANE

REVEAL THAT HERE THE MOUNTAINS HAVE RISEN UP FROM THE DEPTHS

WITH UNUSUAL RAPIDITY,

ABOUT 1/3 OF AN INCH PER YEAR.

THIS IS VERY FAST GEOLOGICALLY

AND PROBABLY COULD NOT HAVE HAPPENED

IF THE CRUST WERE NOT BEING PULLED APART SO STRONGLY

IN NORTHERN ITALY.

TO TOP OFF THESE FINDINGS,

GPS STUDIES ALSO SHOW THAT THE APENNINES ARE INDEED ALIVE

AND MOVING HORIZONTALLY IN SOME AREAS.

THE DATA INDICATE THAT IN SOME PARTS OF TUSCANY,

THE EARTH'S SURFACE IS SPLITTING APART

ABOUT A 1/6 OF AN INCH PER YEAR.

THE DATA ALSO SHOW THAT THE ITALIAN BOOT

IS STILL SWINGING BACK AS IF TO KICK.

- EMERGING DOWNSTREAM HERE?

- YEAH, I THINK THAT IT COMES THROUGH WHERE THIS FAULT RUNS.

narrator: ALL OF THIS EVIDENCE FITS WELL WITH THE THEORY

THAT ROLLBACK IS OCCURRING IN ITALY.

THE SEISMIC STUDIES CLEARLY SHOW THAT THE ADRIA MICROPLATE

HAS SUNK DEEP INTO THE MANTLE.

THIS HAS HAPPENED OVER MILLIONS OF YEARS,

BOTH SQUEEZING THE APENNINES UPWARD

AND PULLING THEM APART.

IT'S A PROCESS THAT BALANCES TWO OPPOSING FORCES,

AND LIKEWISE, ITS IMPACT ON PEOPLE

CAN BE SEEN AS BOTH BENEFICIAL AND HARMFUL.

EARTHQUAKES AND VOLCANOES CAN CAUSE TREMENDOUS DAMAGE,

BUT THEY ALSO MAKE FOR A BEAUTIFUL BOUNTIFUL LAND.

WITHOUT TECTONICALLY ACTIVE GROWING MOUNTAINS,

THE GREAT MARBLE OF CARRARA

WOULD NEVER HAVE SEEN THE LIGHT OF DAY

AND THE ART OF THE RENAISSANCE

MIGHT HAVE TURNED OUT VERY DIFFERENTLY.

- STREAM THIS POINT OF ROCK COMES RIGHT OUT HERE...

narrator: MEANWHILE, FRANK PAZZAGLIA

AND HIS COLLEAGUES

HAVE BEEN ADDING THEIR OWN BRUSHSTROKES

TO ITALY'S COMPLEX GEOLOGIC PORTRAIT.

IT'S AN ELEGANT AND UNUSUAL PORTRAIT,

AND LIKE MICHELANGELO'S UNFINISHED PRISONERS,

IT'S NOT YET COMPLETE.

[gentle orchestral music playing]

WORKING ON ITALIAN GEOLOGY IS A CHALLENGE, CERTAINLY,

BUT DELIGHTFUL, LIKE SO MUCH ELSE IN ITALY.

- I ALWAYS LAUGH BECAUSE NO ONE EVER FEELS SORRY FOR YOU

WHEN YOU TELL THEM THAT YOU HAVE TO GO DO WORK IN ITALY.

- IT'S A WONDERFUL PLACE TO WORK.

IT'S GOT BEAUTIFUL WEATHER, BEAUTIFUL SCENERY.

- IT'S VERY FERTILE BECAUSE IT'S ACTIVE.

IT'S VERY BEAUTIFUL BECAUSE IT'S ACTIVE.

THE REASON THAT ITALY IS WHAT IT IS

IS BECAUSE TECTONICALLY IT'S AN ACTIVE PLACE.

female announcer: ITALY'S MYSTERY MOUNTAINS

IS AVAILABLE ON DVD.

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