St. Helens: Out of the Ash

DEVELOPMENT OF THE OTHER ANIMALS AND PLANTS THERE. THIS, IN TURN, HAS AN IMPACT ON THEM. THEY CAN hit the wall, if you will, against the available food supply that they have in the capacity of that lake to sustain them. SO IT IS NOT CLEAR THAT A FISH POPULATION OF THAT SIZE AND LARGE IS ABLE TO SUSTAIN ITSELF. Kartevold: NO MATTER WHAT THE RESULT IS, IT WILL BE ONE DICTATED BY NATURE. SPIRIT LAKE AND THE CORE OF THE MONUMENT, THE AREA AND VALLEY DIRECTLY TO THE NORTH AND WEST OF THE VOLCANO, ARE WITHIN AN AREA DEDICATED TO RESEARCH, AND THAT AREA IS RESERVED FOR LONG-TERM STUDIES OF THE NATURE THAT FOLLOWS ITS COURSE.

So basically SPIRIT Lake is being left to recover on its own, and those fish in the lake that we're watching and the biologists are watching and basically watching the natural environment progress on its own. Kartevold: THE MOUNTAIN AND ITS SURROUNDINGS WERE DECLARED A NATIONAL MONUMENT IN 1982, AND HAVING A LARGE PART OF LAND UNDER EXCLUSIVE FEDERAL CONTROL HAS PROVEN TO BE ADVANTAGE DURING MORE RECENT ACTIVITY. ONE OF THE CHALLENGES OF VOLCANOES IS THAT THEY DISTURB LARGE AREAS, ESPECIALLY WITH THINGS LIKE MUD FLOWS WHICH CAN TRAVEL MANY MILES FROM THE VOLCANO. IT'S CERTAINLY MUCH EASIER WHEN THE AREA AROUND THE VOLCANO IS ENTIRELY WITHIN FEDERAL OWNERSHIP, AND WE CAN ESTABLISH THINGS LIKE THE FIVE MILE RADIUS CIRCLE AROUND THE VOLCANO AND ACTUALLY GET PEOPLE TO COME BACK BEYOND THAT.

SO IT'S MUCH EASIER TO DRIVE AND ALSO SEE WHAT'S GOING ON AROUND THE VOLCANO. Kartevold: BY STUDYING AT THE MONUMENT, GEOLOGISTS CAN SEE HOW MOUNT ST. HELENS IS CONNECTED TO A HISTORY DATING BACK TO MILLIONS OF YEARS. BELOW THIS LEVEL, BETWEEN HERE AND MY FEET, WE ARE DEALING WITH A PERIOD OF TIME THAT EXTENDS FROM 1480 AD. UP TO APPROXIMATELY 3300 YEARS BEFORE THE PRESENT. Kartevold: WHAT YOU LEARN HERE CAN HELP PROVIDE INFORMATION TO THE REST OF THE CASCADE RANGE AND OTHER VOLCANOES AROUND THE WORLD. THE MOST UNIQUE LEARNING OPPORTUNITIES THAT RESULTED FROM THE EVENTS OF 1980 HAD TO DO WITH THE AVALANCHE AND DEBRIS EXPLOSION.

IMAGES AND WITNESSES INFORMATION PROVIDED BY PEOPLE LIKE GARY ROSENQUIST AND DOROTHY STOFFEL GAVE SCIENTISTS THE OPPORTUNITY TO UNDERSTAND A PHENOMENON THEY HAD NEVER PRESENTED BEFORE. DUE TO OBSERVATIONS ON MOUNT ST. HELENS OF THE EVENT AND THEN THE DEPOSITS IT PRODUCED, WE HAVE REALIZED THAT EVENTS LIKE THAT SECTOR COLLAPSE WITH ITS GREAT SLIDE HAVE OCCURRED MANY TIMES IN EXPLOSIVE VOLCANOES AROUND THE WORLD. SO IT'S A COMMON EVENT BUT ONE THAT WE WERE NEVER REALLY PREPARED TO APPRECIATE BEFORE. Kartevold: YOU CAN ALSO SEE CLOSE UP HOW THE VOLCANO IS RECONSTRUCTED. AFTER THE ERUPTION ON MAY 18, THE CRATER FLOOR WAS RELATIVELY FLAT.

IN FACT THERE WAS A KIND OF DImple OR DEPRESSION WHERE THE FAN WAS BELOW WHERE THE CURRENT DOME IS, AND SEVERAL TIMES DURING THE SUMMER OF 1980 A SMALL INcipient DOME STARTED TO GROW ON THAT FAN, BUT EACH TIME A LATER, SMALLER EXPLOSIVE ERUPTION THAT ON MAY 18TH DESTROYED THE SMALL DOME AND THE DOME HAD TO START AGAIN. AFTER THAT SUMMER WAS OVER, THEN THE DOME BEGAN TO BE ABLE TO GROW WITHOUT BEING DESTROYED, AND IT GROWED IN A SERIES OF ABOUT 17 EPISODES OF DOME BUILDING THAT OCCURRED FROM THE END OF 1980 THROUGH OCTOBER 1986 AND THEN THEY FAN OFF.

THE DOME STOPPED GROWING AT THAT MOMENT. Kartevold: THE 1980 DOME IS APPROXIMATELY 3,000 FEET WIDE AT THE BASE AND OVER 800 FEET HIGH. IT IS THE RESULT OF THE MAGMA DEPLETED IN GAS THAT REMAINED FROM THE ERUPTION ON MAY 18. THE SERIES OF SMALL ERUPTIONS THAT BUILT THIS DOME LAST OVER MORE THAN HALF A DECADE. AFTER THAT, MOUNT ST. HELENS STAY SILENT. IT WAS A SILENCE THAT WOULD KEEP FOR 18 YEARS. THEN, IN OCTOBER 2004, THE MOUNTAIN CLEARED ITS THROAT AND BEGAN TO REBUILD ITSELF ONCE AGAIN. IN A RELATIVELY SHORT PERIOD OF TIME WE ACCUMULATED A LARGE NUMBER OF MAGNITUDE 2 EARTHQUAKES, WHICH WAS VERY UNCOMMON ON MOUNT ST.

HELENA. ON APPROXIMATELY SEPTEMBER 28TH, WE STARTED TO SEE THIS AREA BEHIND THE OLD LAVA DOME AND THE GLACIER LIFT AND CRACK. OBVIOUSLY SOMETHING WAS MOVING NEAR THE SURFACE AND DISTURBING THE GROUND. SHORTLY AFTER WE DETECTED THE FIRST TRACES OF VOLCANIC GAS AND, OF COURSE, ON OCTOBER 1 WE HAD THE FIRST EXPLOSION. SEVERAL MORE FOLLOWED IN THE FOLLOWING DAYS. AND WE PASSED VERY QUICKLY FROM SLEEPY MOUNT ST. HELENS TO AN ERUPTION IN PROGRESS. Kartevold: THE NEW DOME STARTED TO APPEAR BETWEEN THE 1980'S DOME AND THE CRATER WALL, SPLITTING AND PUSHING AWAY THE GLACIER THAT WAS GROWING IN A HORSESHOE SHAPE AROUND THE CRATER RIM SINCE 1986.

THIS CAME OUT AT AN ANGLE , AND SO IT'S BASICALLY A RECLINING COLUMN THAT KEEPS PUSHING OUT, DISASSEMBLING AND THEN REFORMING, AND PUSHING ON ITS OWN RESIDUES. Kartevold: UNLIKE THE 1980 DOME, WHICH WAS BUILT OVER SIX YEARS IN PATCHES, ONE LOBE STACKED ON TOP OF THE NEXT, THIS DOME, CALLED WHALEBACK, HAS BREAK OFF THE SURFACE AND WAS FORMED IN A MORE CONTINUOUS FASHION. BEST THAN 40 MILLION CUBIC METERS SO FAR IN SIX MONTHS. THAT'S HALF THE VOLUME OF THE ANCIENT LAVA DOME IN JUST SIX MONTHS INSTEAD OF SIX YEARS. THAT'S VERY NOTABLE IN ITSELF. BUT ACCOMPANYING THAT EXTRUSION THERE ARE NO EXPLOSIONS.

THERE HAVE BEEN SMALL EXPLOSIONS LIKE THOSE IN EARLY OCTOBER, BUT WE HAVE NOT HAD ANY SUBPLENIUM OR PLENIUM COLUMNS, THE COLUMNS OF ASH THAT RISE DRIVEN BY THIS RAPID EXPANSION OF THE GASES COMING OUT OF SOLUTION IN THE MAGMA. THAT TELLS US SOMETHING FUNDAMENTAL ABOUT THIS MAGMA, ABOUT ITS POTENTIAL DANGERS IN THE FUTURE, AND ONE OF THE THINGS WE ARE LOOKING VERY CLOSELY IS ANY EVIDENCE OF MORE GAS-RICH MAGMA. Kartevold: WHILE THE DEVELOPMENT OF THE WHALE DOME IS EXCITING, GEOLOGISTS HAVE ALREADY LEARNED A LOT BY EXAMINING OLDER FORMATIONS EXPOSED BY THE 1980 ERUPTION. MUCH OF WHAT GEOLOGISTS SEE IN THE CRATER MATCHES WHAT THEY ALREADY BELIEVE IS THE GENERAL SEQUENCE OF EVENTS THAT HAD BUILT THE MOUNTAIN.

BUT THE OPEN CRATER GIVES THEM A NICE CROSS-SIDE VIEW OF THE MOUNTAIN'S PAST. WHEN LOOKING AT THE WALLS OF THE CRATER, YOU SEE THAT MANY OF THE WALLS OF THE CRATER ARE COMPOSED OF VERY LIGHT COLORED ROCK, AND THAT LIGHT COLORED ROCK REPRESENTS DOMES THAT ERUPTED ON THE VOLCANO, SHORT TO THE SURFACE, BUILT DOMES, SOMETHING LIKE THE ONE WHO IS BEHIND US, ABOUT 3,000 YEARS AGO. Kartevold: IN THE POMEZ PLAIN CREATED BY THE LANDSLIDES AND PYROCLASSIC FLOWS OF THE 1980S, SCIENTISTS CAN SEE WHERE YOUNG AND OLD ARE FOUND. THOSE ROCKS ARE PART OF A SEQUENCE OF VOLCANIC ROCKS THAT ACCUMULATED BETWEEN 38 AND 24 MILLION YEARS IN A LONG BELT THAT EXTENDS FROM MOUNT RAINIER IN THE STATE OF WASHINGTON TO SOUTH OF WASHINGTON AND THE STATE OF OREGON.

THE YOUNGER ROCKS BUMPING AGAINST THAT CLIFF ALL DERIVED FROM MOUNT ST. HELENS, AND NEAR THE BASE OF THE CLIFF YOU CAN SEE SUBTLE PUMICE LEFT FROM THE DEBRIS AVLANCHE ON THE MORNING OF MAY 18, 1980. THE HORIZONTAL LAYERED ROCKS SEEN ON THE SMALL CANYON WALL ARE FLOW DEPOSITS PYROCLASTIC FROM THE SUMMER OF 1980. Kartevold: IN THE SUMMER OF 1980 THIS WAS A SMOOTH SURFACE. BUT EROSION BY STREAMS DRAINING FROM MOUNT ST. HELENS HAVE CUT DEEP CANYONS IN THE PYROCLASTIC FLOW DEPOSITS. IT WILL CONTINUE TO CHANGE DRASTICALLY OVER DECADES. THERE WILL BE CONTINUING EROSION, BUT ON THE OTHER HAND, THE DEPOSITS IN THESE WASHES TEND TO FILL SOME OF THE LOW PLACES AS WELL.

THIS IS WHAT IT WILL BE EVOLVING. Kartevold: AS THE MOUNTAIN EVOLVES, SO DOES THE TECHNOLOGY SCIENTISTS USE TO TRACK IT. ALL OF THE CASCADE MOUNTAINS ARE MONITORED TO SOME DEGREE, BUT FROM MOUNT ST. HELENS IS THE MOST ACTIVE, GETTING EXTRA ATTENTION. THIS IS THE FIRST ERUPTION IN WHICH WE HAVE USED THIS FLIR INSTRUMENT, WHICH IS A FORWARD-LOOKING INFRARED INSTRUMENT. IT'S BASICALLY THE SAME TYPE OF CAMERA THAT THE POLICE USES TO FIND WARM BODIES RUNNING AT NIGHT. AND THE ONE WE HAVE WE CAN CALIBRATE. SO THAT WE CAN REALLY KNOW THE SPECIFIC TEMPERATURES. THAT WAS VERY HELPFUL AT FIRST WHEN WE STARTED TO SEE THAT IN FACT THERE IS HOT MATERIAL NEAR THE SURFACE.

Kartevold: DATA COLLECTION IS VITAL TO UNDERSTANDING WHAT CAN HAPPEN, BUT A VOLCANO CRATER IS A DANGEROUS LABORATORY. WE LAND NEXT TO THIS MASS AND LOOK UP. IT WAS LIKE LOOKING AT AN EXTREMELY STEEP SLOPE. IT WAS A STRIPED SLOPE. YOU COULD SEE HOW THAT SURFACE WAS JUST DRAWN OFF THE FLOOR, SCRATCHED, TO MAKE THESE GROVES IN IT. THAT ENDS UP BEING ONE OF THE MOST NOTABLE AND INTERESTING SCIENTIFIC THINGS ABOUT THIS ERUPTION, IS HOW THAT MATERIAL WAS PRODUCED AND HOW IT WAS STRIKED. Kartevold: THE SURFACE OF THE WHALE'S BACK IS COVERED WITH ONE TO TWO METERS OF FALLA GABURA.

FROM A DISTANCE IT LOOKS LIKE A SMOOTH WHITE ROCK. BUT THE ROCK ITSELF IS REALLY NOT A ROCK. IT'S JUST GROUND LIKE POWDER. IT FALLS IN YOUR HAND. THIS IS THE KIND OF THING THAT HAPPENS ALONG FAILURE ZONES WHEN MASSES OF EARTH PLATES RUB AGAINST EACH OTHER AND GRIND EACH SIDE TO MAKE THAT KIND OF DUST. THAT'S WHAT WE'RE SEEING IN ST. HELENA. IT'S REALLY UNUSUAL. THIS KIND OF THING, TO OUR KNOWLEDGE, HAS NOT BEEN DESCRIBED WITH THIS THICKNESS ANYWHERE ELSE ON EARTH. Kartevold: ALTHOUGH THE INFORMATION LEARNED IS VITAL, MANUAL COLLECTION OF DATA FROM AN ACTIVE VOLCANO IS GENERALLY NOT POSSIBLE.

THAT'S WHY NECESSITY IS THE MOTHER OF INVENTION. IN THIS CASE, THE INVENTION IS CALLED "SPIDER". WE NEED INSTRUMENTS NEARBY. ON SEVERAL OCCASIONS WE HAVE LOST THEM THROUGH EXPLOSIONS. ONE OF THE SCIENTISTS HERE DEVELOPED BASICALLY PORTABLE INSTRUMENTS THAT COULD BE LAUNCHED BY HELICOPTER, AND AS FAR AS WE KNOW, THIS IS THE FIRST ERUPTION IN WHICH THESE PORTABLE INSTRUMENTS HAVE BEEN USED. So we've been able to hang seismometers, GPS instruments or gas sensors very quickly by helicopter, set them up and leave them. Kartevold: THE 1980 ERUPTION RESULTED IN A QUANTUM LEAP IN GEOLOGISTS' UNDERSTANDING OF THE OPERATION OF VOLCANOES.

HOWEVER, THERE IS STILL A LOT TO LEARN. FOR EXAMPLE, BY STUDYING MICROSCOPIC CRYSTALLINE FORMATIONS IN ROCK SAMPLES TAKEN FROM THE NEW DOME, THEY HOPE TO DETERMINE WHETHER FUTURE ERUPTIONS WILL BE VIOLENT OR NOT. IF A MAGMA RISE VERY FAST FROM THE DEPTHS, THE GAS THAT DISSOLVES IN IT WILL LEAVE THE SOLUTION VERY FAST. THAT'S WHAT DRIVES EXPLOSIONS AND EXPLOSIVE ERUPTIONS. If you live on the flanks of a volcano, if you're downwind on a plane, we've even had 747s come close to crashing from ingesting ash into the engines. SO WE NEED TO KNOW HOW MUCH GAS THERE IS IN THE MAGMA.

WE NEED TO KNOW HOW LIKELY IT IS OF PRODUCING AN EXPLOSIVE ERUPTION. SO WE GET ALL THAT INFORMATION BY ANALYZING THE CRYSTAL, LOOKING AT THE TEXTURES, HOW THIS MATERIAL HERE IS IN WHAT IS CALLED EARTH MASS, HOW IT GROWN. ALL THE WORK WE DO HERE IS AIMED AT UNDERSTANDING HOW VOLCANOES WORK, BECAUSE WE HAVE TO HAVE THAT UNDERLYING SCIENTIFIC BASIS IF WE ARE GOING TO BE ABLE TO SAVE LIVES AND PROPERTY IN THE END. Kartevold: THE LAST ACTIVITY HERE ON MOUNT ST. HELENS JUST OUR MOST RECENT REMINDER THAT WHEN THE MOUNTAIN FOLLOWS SILENCE, EVEN FOR YEARS, WE HAVE TO REMEMBER THAT SHE IS ONLY SLEEPING.

VOLCANIC ACTIVITY HERE WILL CONTINUE, AND NO MATTER HOW GOOD WE ARE AT MONITORING IT, THE MOUNTAIN AND ONLY THE MOUNTAIN WILL DICTATE WHAT COMES NEXT.