>> HELLO, BUDDY AND TINY.

YOU SEEM VERY EXCITED TODAY.

>> WE ARE!

>> CAN YOU GUESS WHERE WE'RE GOING?

>> WE'LL GIVE YOU A HINT.

IT'S SHAPED LIKE THIS.

>> AND DAD SAYS THAT HOT, MELTED ROCKS CAN SHOOT OUT OF ITS TOP.

>> HMM.

I DON'T SUPPOSE YOU'RE GOING TO SEE A...VOLCANO?

>> YES!

YOU'RE ALWAYS RIGHT.

WE ARE GOING TO A VOLCANO.

>> I'LL BET YOU KNOW A LOT ABOUT THEM.

>> I KNOW A THING OR TWO.

MY GUESS IS YOU'RE GOING TO SEE OUR LOCAL VOLCANO, OLD SMOKY, THE ONE WE CAN SEE FROM THIS VERY TRAIN.

>> THAT'S THE ONE.

RIGHT, DAD?

>> THAT'S RIGHT, TINY.

I WAS TELLING THE KIDS THAT OLD SMOKY'S BEEN SMOKING MORE THAN USUAL LATELY.

>> GOOD OBSERVATION.

>> I'VE NOTICED THAT, TOO, MR. PTERANODON.

I THINK MORE THAN SMOKE IS GOING TO COME OUT OF OLD SMOKY, AND VERY SOON.

>> WHAT DOES COME OUT OF A VOLCANO?

>> WHY DOES ANYTHING COME OUT OF A VOLCANO?

>> EXCELLENT QUESTIONS.

YOU SEE, DEEP UNDER THE SURFACE OF THE EARTH, IT'S REALLY, REALLY HOT.

>> SO HOT THAT IT MELTS ROCKS?

>> EXACTLY, AND THE HEAT PUSHES THOSE MELTED ROCKS, CALLED LAVA, UP, UP UNTIL THEY ERUPT OUT OF THE TOP OF THE VOLCANO.

HUZZAH!

>> ERUPT?

>> YEP.

ERUPT MEANS TO SHOOT UP AND OUT, LIKE WHEN THE LAVA BLASTS OUT OF THE VOLCANO.

IT ERUPTS.

HEH!

>> AHEM!

OH, YOUR DAD IS, UH, ONE SMART PTERANODON.

HEH HEH!

YOU KNOW, I'VE TRAVELED THIS TRAIN LINE EVERY DAY PAST OLD SMOKY, AND FOR YEARS IT'S JUST MADE SMOKE.

BUT I THINK IT'S ABOUT TO ERUPT, AND TODAY COULD BE THE DAY.

>> [GASPS] OOH!

I HOPE WE GET TO SEE IT ERUPT.

>> IT COULD HAPPEN, TINY.

WE COULD GET LUCKY AND OLD SMOKY MIGHT SHOW US MORE THAN SMOKE.

>> WE WANT LAVA!

WE WANT LAVA... >> WELL, BRUSH MY PAWS AND TRIM MY CLAWS!

THERE'S OLD SMOKY NOW.

>> WHOA!

>> NEXT STOP, VOLCANO VALLEY!

VOLCANO VALLEY STATION, FOLKS!

[BRAKES CREAK, STEAM HISSES] THERE'S THE PATH UP TO THE VOLCANO VALLEY VIEWING POINT, FOLKS.

>> THANKS, MR.

CONDUCTOR.

>> WE'LL TELL YOU ALL ABOUT IT ON THE WAY BACK!

WHOA.

IT'S BEAUTIFUL.

>> IT'S AMAZING.

>> IT'S PRETTY SPECIAL, KIDS, LIKE NOTHING I'VE EVER SEEN BEFORE.

>> YOU KNOW WHO ELSE HAS NEVER SEEN ANYTHING LIKE THIS BEFORE?

>> MOM AND SHINY AND DON?

>> THAT'S EXACTLY WHAT I WAS THINKING.

I BET THEY'D LOVE TO SEE THIS.

>> I AGREE, KIDS.

THIS IS A ONCE-IN-A-LIFETIME CHANCE TO SEE OLD SMOKY ERUPT.

I BET W WE STIL HAVE TIME.

LET'S HURRY BACK TO THE NEST AND GET THE REST OF TEAM PTERANODON.

>> H HOORAY!TH SHAKE, TOO?

>> YEAH.

>> WE ALL DID, DON.

>> AND LOOK.

WOW.

IT'S MAKING MORE SMOKE THAN EVER.

>> THERE'S A RUMBLING NOISE.

THE GROUND IS SHAKING.

THE VOLCANO IS LOOKING HOTTER AND HOTTER.

OLD SMOKY LOOKS LIKE IT REALLY WANTS TO ERUPT.

>> LOOK!

IT'S--IT'S-- >> IT'S ERUPTING!

>> WHOA!

OOH!

AHH!

>> [SQUAWKS] IT'S SPECTACULAR!

>> YEAH, THE MOST AMAZING THING I'VE EVER SEEN.

>> BLESS MY SCALES AND FEATHERS!

WHAT A MAGNIFICENT SIGHT!

>> THE BEST VOLCANO EVER.

>> LET'S HEAR IT FOR THE VOLCANO!

>> VOLCANO!

VOLCANO!

VOLCANO!

>> HI THERE.

I'M DR. SCOTT, THE PALEONTOLOGIST, AND THIS IS A VOLCANO.

>> VOLCANO.

>> VOLCANOES HAPPEN WHEN MELTED ROCKS DEEP UNDERGROUND BURST THROUGH THE EARTH'S SURFACE, CAUSING AN ERUPTION.

AFTER THAT MELTED ROCK ERUPTS OUT OF THE EARTH, WE CALL IT LAVA.

>> KABOOM!

>> NOW, MANY VOLCANOES FORM CONE-SHAPED MOUNTAINS LIKE THIS ONE, WITH A HUGE CRATER AT THE TOP WHERE THE LAVA COMES OUT.

ONCE THE LAVA COOLS OFF, IT LOOKS LIKE THIS.

>> WOW!

>> VOLCANOES ARE FOUND ALL OVER THE WORLD, EVEN UNDERWATER.

SOME ISLANDS, LIKE THE HAWAIIAN ISLANDS, ARE ACTUALLY MADE FROM LAVA THAT ERUPTED FROM VOLCANOES AT THE BOTTOM OF THE OCEAN.

YOU CAN STILL SEE LOTS OF OLD LAVA TODAY ALL OVER HAWAII.

WELL, THAT'S ALL FOR NOW.

REMEMBER, GET OUTSIDE, GET INTO NATURE, AND MAKE YOUR OWN DISCOVERIES.

>> VOLCANO!