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core power yoga cherry hills
major fundingwas provided by nebraskans forpublic television. narrator: among the world's mountains and seas nebraska is but a tiny grain of sand. hidden in its landscape
core power yoga cherry hills, is a history that was carved by a series of natural disasters occurring over five billion years. geologic time locked in layers upon layers like pages in a book.
each layer, forming a foundation for today's landscape. a land that appears peaceful but beneath the surface scientists are uncovering a restless prairie. the earthquake wouldhave had to have been somewhere up in thevicinity of richtermagnitude seven. it was the naturalforces of erosionthat created it and now it's the naturalprocesses of erosionthat's taking it down. narrator: pealing back the layers of time
scientists can uncover nebraska's natural history. along the way, finding clues to our own future survival. some of the consequences ofenvironmental disasters thatwe see in the fossil record are quite scary. big time drought. these duneswere bare. i thinkby lookingat the past we have a betterunderstanding of thedamage maybe we could do or even the good wecould do in the future.
(* music ) narrator: the land known as nebraska has survived milestones of extreme change. 300 million years ago the state would have been perched on the top of a mountain. 100 million years ago would show the region flooded by a great inland ocean with sea creatures and giant reptiles. over the next millions of years as the sea level fell and the rocky mountains uplifted
water and erosion carved ancient rivers and aquifers. 800,000 years ago, eastern nebraska may have looked like antarctica. as the ice age drew to a close much of today's landscape was intact. it left a gift of fertile cropland to the east to the west badlands and the sandhills the largest area of sand dunes in the western hemisphere. the sandhills were the last major change recorded in nebraska's geologic history.
jim goeke: i thinkit's an awesome sight. i think when youfirst look at it you say, there isn'tanything out here and yet when you realize whatthis represents as far as theaccumulation of these sands the historyof the area an opportunity to captureand transfer water i don't thinkwe can ever take for granted anypiece of topography. narrator: the sandhills and its groundwater
are like a magnet to hydrologist jim goeke. how high youwanna' come up? jim goeke: many peoplein the water industry think that water'sbeen undervalued for years. i guess the value ofwater is best realized whenthere's a time of shortage. narrator: the high plains aquifer known as the ogallala flows beneath nebraska and extends as far south as texas. sand and gravel act as a sponge storing water below the surface.
the thickest part is under the nebraska sandhills. the ogallalaitself is probably4 or 500 feet thick and allof that'ssaturated. 66% of the supply inthe high plains aquifer is concentratedwithin nebraska and that's a couplethousand times the storageof lake mcconaughy. we've got two anda quarter billion acrefeet of water in storage between the grains of sands andsilts and gravels that comprisethe high plains aquifer. narrator: even with all that water
the sandy dunes above won't allow for the area to be used as cropland. with 13 million acres of grassland cattle ranching is the dominant business. all aspects of the cattle business are researched at this working sandhills ranch the university of nebraska's gudmansen ranch. for how many acres? about 13,000 acres. yeah.
a thousand acres! that's aplantationin maine! narrator: water experts from around the country representing the likes of the epa and dupont chemical have come to get a closer look at the water rich sandhills. there are a lot ofbison bones up here. almost looks likea socket of somesort of a leg bone. a lot of history here. narrator: at birdwood near lake mcconaughy
nature provides physical evidence that abundant groundwater is often close to the surface in the sandhills. and if you don'tbelieve that there'swater underground you don't have todrill a well here. the land surface isincised to the point where you see theintersection of the bottom ofthe valley in the water table. year round it'salways like that. and it's not thelarge artesian springs. it's aseepageface.
in much ofthe sandhills the groundwaterreservoir is full. it supports theflow of streams. it supportswet meadows and anytime we talkabout groundwaterand surface water it's a semanticdifference. narrator: among the groundwater outcrops in the sandhills perhaps the most revealing are the natural springs. there it is.
like old faithful it sort of --it sort of bubbles and... miniature old faithful? narrator: springs like little growler suspend sand creating a loose quicksand that periodically boils or bubbles. we could only getdown about 20, 25 feet. i don't know thatthat's the bottom of it. let's wander backon up here and takea look at old growler. that isabsolutelyamazing. narrator: a boiling spring known as old growler
is one of the largest and locals say it's been around for 100 years. it'll come rightup to the elbow. whoa!!! right on cue, jim! that one spasm was probablythe most active sizablespasm i've ever seen here. i mean thatreally was. for -- as far assustained activity that was -- that wasas good as i've ever seen.
i hope we gotthat on film. allll right! narrator: geologists are puzzled by the springs. neither air pressure nor heat cause the boiling and it's not known if they reach the aquifer below. that is incredible. it's part of thatthe thing you think of and having the realityto be so much morethan you imagined. just to be able to see itand experience it and feel it
feel the texture feel the energy and also just the setting. i mean everyone saysthat groundwater is thelife blood of the state but this is whereyou really get thatfeeling that it is that it's a reallyliving thing. just great. just a great moment. sand weighs a considerableamount per unit volume
and that settles out and forms a pluglike in some geysers and then the pressureunderneath boils up and the sedimentspews out. sometimes itgentle boils and sometimes ratherdramatically like wesaw a few minutes ago. jim goeke: there area lot of questionsyet about groundwater that we have not answeredthat are gonna' be funto explore in the future and we need toexplore those
if we are to better understandthe connection betweensurface and groundwater. narrator: lately specialists are taking a closer look at the human impact on the water supply. when we talkabout a continuumin a water cycle it's truly what goesaround comes around. we had found out thatwe had minute tracesof atrazine in the rain. you're puttingatrazine on a soil and a soil dries out andblows into the atmosphere maybe carrying minute tracesof whatever chemical it is
it's washed outof the atmosphere and those chemicals comeback down on us in the rain and it's justnot acid rain. it can be atrazineand other things. in nebraska we'refavored by overallvery good water quality and although weshould be concerned i don't think weshould be alarmist. we need to bevery conscious ofwhat the quality is but i think thereneeds to be somedegree of moderation.
narrator: the massive water supply in western nebraska is unequaled. in fact, most of the state's important geologic formations are to the west. countless seasons shaped natural wonders as dramatic as snake river falls on the snake river near valentine. it is the state's largest waterfall. nearby, along the niobrara river smith falls was created where a small spring fed creek
drops 75 feet over a rock ledge to the niobrara valley below. as the ice age ended our climate turned warmer and drier. spruce and birch forests which once covered the state could not survive in this warmer climate and was replaced by prairie. but in the cool, wet canyons along the niobrara river remnants of the ice age forest survived. protected from winds at the foot of smith falls
is a colony of a hybrid of quaking aspen, a northern species and bigtooth aspen, an eastern species. native americans named it nebraska. broad, flat water a fair description of the platte river but the rest of the landscape is hardly flat. in the great north platte river valley near the wyoming border scotts bluff national monument rises nearly 5,000 feet above sea level. millions of years ago
this area was roughly a flat bed of rock. there were no chimney rock or courthouse and jail rock but as the ancient platte river carried rocky mountain debris eastward it formed the landscape including a series of canyons and buttes. today the exposed rocks can be 20 to 30 million years old. here's a real nice --some real niceprairie right there. jerry steinhauer:you can tell the impactsof geology on the vegetation the erosion basically.
how aboutright there? narrator: jerry steinhauer and steve rolfsmeier are collecting data at scotts bluff monument. the prairie has changed since the early 1800's when scientists began to map the monument's landscape. now, with the aid of modern technology jerry and steve hope to gather information that can be used to restore the damaged prairie. jerry steinauer:when you look onthese lower slopes
it's just thetypical thing you seein disturbance in prairies. you know, it's whatwe're used to in otherparts of nebraska. you have these downy brome,japanese brome, smooth bromecoming in, kentucky bluegrass. you know, they're allindicators of disturbance. what we're gonna' do is one of our vegetation plots. we use ten by ten meter plots. we'll take quantitativedata in this plot and define theplant communities.
and 4, 6, 3,22, 37 meters. narrator: jerry and steve pinpoint their location on the monument by using global positioning satellite technology. scientists in the future can look at the same plots to see how the prairie changes. jerry steinauer:i really like the nativevegetation, the wildflowers. finding some of theseneat slopes where thevegetation is pristine you get kind of a kickout of it, you know and it's like boy, i wishit all could look like this.
and maybe some of thesethings we can do cankind of bring it back. this is anationalmonument. it should be aplace where peoplecan go and see representative examplesof what the landscapereally looked like. that's probably the best, inmy opinion, reasons for havingsome of these places preserved is to keepthe vegetationlike it was. in addition torecording data we're recording history so that peoplein the future
will be able tosee how thingschange over time and maybe get an ideaof what to expect and how to managethe vegetation to keep it as closeto its originalpristine condition. loren pospisil: it wasthe natural forces oferosion that created it in ourstandpoint we might thinkit's a bad thing but bear in mind thatnothing here lasts forever. narrator: with the help of technology
the native prairie can return to its natural state but science can't stop the power of mother nature. not far from the scotts bluff monument geologic time may be catching up with chimney rock. loren pospisil:the lightning doesfigure into it. in '92,it got hit. four and a halffoot come off and lightningdoes hit it fromtime to time. but bear in mind,it being sandstone
it's always erodingfrom year to year. it's just fromyear to year you may notnotice the changes but in dramaticsorts of experienceslike with the lightning you do noticesizable changes. narrator: since pioneer days 50 feet of the volcanic ash and sandstone have disappeared from the peak. loren pospisil: one ideawas is that we shouldtake a whole gob of cement
and restore it toits original height. that would,of course, be tricky. another idea actuallydone by one of the peopleusing our drawing board at the visitor center involved puttinga big umbrellaover the structure and that would, of course,be quite interesting but notnecessarilyworkable. the name itselfstarts to come intoplay fairly early. in 1823 someone referred to itas chimney rock or the chimney.
other things that it'sbeen called is the nosemountain or the nose peak. the indian culture herehad their own names for it. and sometimes it'sdifficult to be polite but bear in mind thatpeople living on the plains may not have hadaccess or experiencewith chimneys and at leastby local indians it was referredto as elk penis. narrator: it is the most famous landmark on the oregon trail. chimney rock was mentioned in 95% of pioneer diaries.
loren pospisil:for me, chimney rock isa symbol of the west itself and also the peoplethat were traveling thisroute a century and a half ago it was a symbolof the west. it was a symbolof things to come. narrator: traveling to the far northwest corner of nebraska early explorers found a dry rugged land, too barren to sustain life. today, it is a good illustration of toadstool park a secluded 800 acres of badlands within the oglala national grassland toadstool is like a mysterious and desolate companion to the moon.
apollo 11,this is houston. you are a go for... apollo 11, thank you. roger out. houston,tranquillitybase here. the eaglehas landed. narrator: when neil armstrong walked on the moon his feet were imprinted in a thick layer of volcanic dust millions of years old. the volcanic landscape mimics the alien shapes at toadstool.
hannan lagarry: volcanic ashwas ejected into the atmosphere and then the windcarried it to thisarea to the east where itwas depositedmuch like dust and it mixed withthe other sediments and so the rocksaround us are anywherefrom 30 to 50% volcanic ash that was broughtby winds from the west and depositedin this area. narrator: geologists are finding that toadstool park wasn't always the dry and barren land it is today.
it was a living world with abundant animal life and a waterway much like the platte river is today. in between this, the wetenvironments and thevery dry environments is the formation in whichthese trackways were produced. what we'relooking at is a runway of rhinoceros thatlived in this area between31 and 33 million years ago. you can see thatit's three-toed and this happens to be what wefeel is a track of a hyracodon which is a small rhino.
it shows that thehyracodons wanted to getacross this river system. they're more interestedin moving right along so that they're notbasically lunch to anybody and getting eaten by thesaber-toothed cats thatwere around at the time. as you followthe tracks along the sub-hyracodonsare paralleling the stream and they'rewalking along and as you walkacross this and you'refollowingthose tracks
they must leadsomewhere and they do. they walk rightalong this ridge and they follow along hereuntil you get to this erosionalfeature of this canyon and the actualerosion of this canyon undercuts the actualtrackway slabs themselves and they fall down. so it's kind of one of thosestories that to our knowledgefor this age of material isn't preservedanywhere elsein the world. david nixon: sincewe're looking at a mudflap
mud only stays softa matter of days. if we're beingreally generous we have two weeks here. so all these animalsthat left the tracks had to go throughwithin that period and if somethingsmaller, lighter had crossed thisvery soft bed it would haveleft a trail. so for right now,this looks like thiswas the last guy out.
there are a multitudeof things at toadstool that the preservationmust have been just like that. like dave was sayingthese tracks couldn'thave been preserved if it wouldn'thave been rapid. if it would havebeen, you know, aslow forming process. water most likely wouldhave cut all this away and there's really noguaranteed answer thatwe can prove right now on why do we havethese tracks here. wellll, we're notreally sure whywe have 'em here.
all we do know isthat they're here and they reallytell a good story. hannan lagarry: in thefour years, five yearsi've been out here working i've seen the completedestruction of half a dozenimportant trackway slabs. sandstone slabsbeing damaged frompeople walking on them and thingslike toadstoolsbeing toppled. and one of our goalsbeginning this year is to construct acatalog of various typesand kinds of trackways using latex peels.
and it wouldprobably mean that a creature walked acrossthis when it was really wet. brantly wells: the reallynice thing about it is that it doesvery little damage and it gives us a perfectmold of what these tracksreally looked like. our latex peels hadabout 36 hours to dry. the bird trackspreserved pretty nice. brantly wells:from this latex peel we can then make plasterreplicas of it and then paintthose and put 'em in a museum
and you won't knowthe difference as far as whether you'relooking at a piece of rockor a piece of plaster. narrator: to help get a clear picture of the past geologists need to understand paleontology. the volcanic ash and clay soil mixture has made the area a fertile ground for preserving fossils of extinct mammals. i'm applying a chemicalpreservative to thebone at the site. the animal preservedhere is a titanothere.
this animal would havestood between six andeight feet at the shoulder very massive legs,very large skull with very large teeththat had a patternon their cusps that indicate to thepaleontologists thatthe animal grazed. this site wasa vandalized site. somebody had come ontothe national grasslands and illegally excavatedone of the vertebrae. 25% of all the sensitivesites we've located over fouryears have been vandalized. if all you're interestedin is acquiring an object
you know,to impressyour friends that's okay. your friends mightneed impressing but if you're wantingto work out why mammalsat 35 million years ago went extinct at33 million years ago because similarenvironments are beingdegraded in the modern world it's very difficult to do thatwithout all the clues you needto conduct your detective work. it's like conductinga murder investigation and then the smoking gunwas taken away and hidden.
dinosaur extinctions. one theory is that the --an asteroid hit the earth,created a dust cloud dinosaurswent extinct. these theorieswere used years ago to sort of predict whatwould happen in caseof a nuclear conflict and a similarsort of cloud coverenshrouding the earth. would a similarthing happen and most of the currentspecies go extinct,including ourselves. all these things thatwe learn from the past
help prepareus for what theseenvironments might face and how we can sortof influence the outcomein a direction we'd like. narrator: mysteries are hidden throughout these oglala grasslands. larry todd: 10,000 years ago,the area was very different. you know, you can'tjust walk out ontothis hill slope today and kind ofsquint your eyes. the climate's changed. the vegetation's changed. the landscape itself haschanged rather dramatically.
narrator: just a few miles from toadstool archeologists investigate a mysterious death. larry todd: we're nothere trying to study an instant of what happened in the middle of thesummer at 9,500 years ago and get a snapshotof that event. we're tryingto understand kind ofthe whole motion picture that that one snapshotframe came out of. this is thehudson-mengbison bonebed.
it's the largestpaleo-indian period bisonbonebed in the americas. and paleo-indian is theterm we use for the earlyoccupants of the continent the people over hereat the end of the ice ages. narrator: dr. larry todd leads a team of archeology students from colorado state university. then you get back intohere into the pelvis. the hind leg,the femur, the tibia,down to the hind toes. so there you've gotmost of the bisoncarcass laying there with its head kind ofpointing to the southeast.
narrator: an entire bison skeleton is by itself an impressive find. but the treasure at hudson-meng is the number of animals found. larry todd: there can beas many as 5 to 600 completebison bones per meter square. and what it lookslike that we have here is that this is the remnantsof a large herd of animals that died as they were fairlyclosely packed together here. the bison that we'refinding at this site are an ancestralform of bison
to what we have roamingthe plains today. narrator: exactly how the bison died is the great mystery. the site was first discovered in the 1950's. larry todd: the notionwas that probably a groupof paleo-indian hunters came across or werewatching a herd of bison and as they gotclose to the cliff do something to frighten 'emand run 'em over the edge. narrator: but was there a cliff here 10,000 years ago?
dr. todd and his crew exposed the buried landscape. larry todd: what we'vegot here in this trench is we've been able toexpose in cross-section here kind of a sliceof what this part ofthe hill looked like. and what we can seeis that right along here you can kind of followthat difference betweenthe darker sediments and the lightersediments above it. and as we continueon up here like this it begins to slopeup coming up thereabout like this
and then up intothe next trench it continues onabout like this. there's the top of thatsame soil surface on upto the next one here and on up like that and the initial modelof what happenedhere at the site is that the bisonhad been run overthe edge of the cliff fallen to the base of it and diedas a resultof the fall. well, what we can seenow is that paleosol wejust traced up comes up
and it mantles the cliff,something like that. when the animals died there was a fairlygentle slope back thererather than a cliff. being able toexpose this paleosol has, if anything, kindof added to our mysteryof what went on here. you can think ofanalysis and excavationof a site like this as being aforensic exercise. what killedthe bison? what was theirlast meal like?
and, you know, on andon and on, your standarddetective story stuff. one mandiblelike this we can have four or fivedifferent specialists study and then when weget a group of 'em we can start getting a goodpicture of the herd structure the environment the regional range conditions. the degree of toothwarekind of tells you how muchgrit there is in the diet which kind of tells youhow much rainfall there was
and so there's a wholeseries of information thatwe can get out of there. we have kind of awhole cross-sectionof the population from calves all the wayup to real old animals. and the way diseaseor many diseasesoften operate is the younger animalsor the older, weakeranimals die first and the prime age animalslive a little longer. so this looks like theseanimals died fairly quickly and unless it was anextremely virulent disease that would haveknocked 'em out
you know, within hoursof having contractedit all at once regardless of ageor sex or health status. disease seemssort of unlikely. so we've had to kind ofre-evaluate the whole notionof how the animals died and i guess thebest interpretationwe have at present is that the causeof their death is clearly ambiguous isthe phrase i like to use. but we'renot sure. i kind of like the ideaof a grassfire myself
that would haveswept across the area and sucked out the oxygenand asphyxiated the animals having them die inplace fairly rapidly but that's a realtough one to evaluate. given that the birthingseason we can assumewas during the spring at that timeas it is now that this site --the animals died hereduring the summer. so it throws out allthe possibilitiesof blizzards... louis redmond: themore the generalpublic understands
about what we're doingin places like hudson-meng the more exciting theentire search for theamerican heritage will be. the story ofthe americas is easily, easily asrich as anything anywhereelse in the world. as an american of mixedheritage, both indianand european heritage i'm also coming togrips with the idea that all americanshave been here fora long time now and it isour heritage. it does belong toall of us in some way.
narrator: to help protect the story of hudson-meng plans are being made to build a permanent enclosure. larry todd: theactual artifacts,the bones and the points and the little bitsof stuff we takeout of the ground aren't the realtreasures that we getout of a site like this. the treasureswe get are whatthe environment was like and what peoplemay have been doing and what the bisonmay have been doing and what therangelands were doing.
i see a site like this as beinga gold mine of information setsof a whole variety of sorts. narrator: a thousand years before the mass death at hudson-meng the bison species survived a severe climatic change. at the end of the ice age the great plains weather shifted from cool, wet conditions to a climate substantially hotter and drier than we feel today. most large species could not survive including the mammoth. steve holen: this isthe shaffort mammoth site.
it's west ofstockville, nebraska, on atributary of medicine creek. this site was foundby the shaffort familyabout 40 years ago when this gullywas eroding and they began to find piecesof mammoth bone coming out. narrator: mammoth remains have been found in nearly every county of the state. the southern region is especially rich in mammoth fossils. this rib came outhere about this farand was exposed. steve holen: so farwhat we have found is the remains of apparentlyone single adult mammoth
but we don't know if it'sa male or female at this point. this is one molartooth from a mammoth and you can see thatthese teeth are very large. this is the surface,the grinding surface. these were very efficientfor grinding up largequantities of grass and mammoths wouldeat hundreds of poundsof grass every day. the two largest mammothson exhibit in the worldthat we know of at this time both camefrom nebraska. they stand approximately12 feet tall at the shoulder.
very large creatures,both of them areprobably large males. narrator: evidence suggests that this mammoth died between 13 to 15,000 years ago. steve holen contends that humans fractured the bones to make tools and weapons. some of the patterns thatwould indicate that these limbbones were broken by humans would be this type offracture that cuts acrossthe long axis of the bone. this indicates that thebone was still freshwhen it was broken. we're going to bemaking a plaster castto put on this bone so that it will help protectit as it's transportedback into the laboratory.
steve holen: byexcavating thesetypes of sites we can possiblylearn how long humanshave been in this area. people say they thinkthey know how old the humanoccupation of the new world is but really we reallydon't know at this point. a lot of archeologiststhink that humans onlycame into the new world say maybe around 12,000years ago just prior to whatis known as clovis culture. the evidence earlierthan that is alwayscontroversial at this point and that's why we'revery interested inthese kind of sites to attemptto demonstratein our opinion
that humans werehere much earlierthan clovis culture and indeed wereprobably here by atleast 25,000 years ago at the time beforethe ice sheets moved south. this is a type of spearused by paleo-indians and also usedby clovis people who hunted mammoths in thisarea about 11,000 years ago. this is adetachableforeshaft so you could goarmed with severalof these foreshafts and just one large spearso you wouldn't have tocarry several large spears.
narrator: finding paleo-indian spears and tools would help holen prove his theory. since 1988 archeologists have been searching for evidence at medicine creek. this is thela sena mammoth site. early on we begandating the site and we now know thatthe mammoth is about18 to 19,000 years old and this representsa controversial site because a lotof archeologistsin north america think that the earliestarcheological sites
were of the clovis peopleabout 11,000 years ago anthis site is welldated at 7 to 8,000years before that. narrator: there are hundreds of archeological sites along medicine creek partly because of the soil. unlike the acidic soil in eastern nebraska this loess preserves fossils well. steve holen: loess isa very fine grained silt. it's awind-depositedfine silt that was probablyblown up out ofthe river valleys
and possibly from asfar away as the nebraskasandhills to this location. it was deposited duringthe last glacial period between 21,000 andabout 11,000 years ago. in fact, this bank behind usrepresents the full sequenceof that loess deposition and we have the radiocarbondates from the base to the top showing the timeperiod when thisloess was deposited. narrator: in the upper layers of soil are the remains of more recent inhabitants of medicine creek. we've alsobeen pulling uppottery as well.
narrator: archaeological students from kansas are helping put together the history of the upper republican area. they are continuing excavations from the 1940's that found houses of ancestral indians. donna roper: the onesthat they excavated arenow off in the lake there. reportedly, thereis another house here and you can see it. what they basically werewas the remains of structures that were built betweenabout a.d. 1100, 1300,somewhere in there
and they weresmall houses. it'll be lighter colored soilin which has intruded poststhat had been set in the ground to form the superstructure of the house. a central fire hearth that wouldhave ash and the like in it and then pits thatwere used for storage and for laterdisposal of trash all of which wouldproduce a large numberof really good artifacts of tools, pottery,food remains. you name it, they'reprobably in those pits.
so that's whatwe're looking for here. this is clearlya house that is eroding and it is definitelyworth salvaging thatkind of information before it goes intothe lake which it willin the next few years. it looks likeit's goingto turn into a prettylarge pieceof mammoth bone. steve holen: every timewe go out, it's a gamble. i mean sometimes you seebone coming out of the bank. at least there'ssomething there.
you havesomethingto go on. to understandarcheological sites you reallyneed to understandgeological processes how the siteswere buried why they're buriedas deep as they are and what geologicalprocesses haveaffected the site over however manyyears it's been sincethey were buried. it's always thenew discovery thatyou hope to make that keeps you goingonto the next site
and hoping you'regoing to find somethingthat's very interesting. if it weren't for reservoirs andlandfills in the great plains we would have nothing,nothing to look at. we look at lake faces likethis, wave-cut faces, yeah without those we'd bereally in big trouble. it's going to give usa fresh face to sample. narrator: bill johnson has uncovered many remains of mammoths and other glacial period fossils. recently he made an interesting discovery along the republican river.
bill johnson: we'relocated on bone cove which is one of thesemany inlets that'sflooded by harlan lake. this face is unusualin that it's the firsttime in the mid-continent that i've ever beenable to find a fault. in other words,where there's abreak in the material and there'sbeen movementalong that break. and we know howmuch the fault moved bycomparing this buried soil. this is an old soilright up in here. this break occurredright here and slidthis side down to here
so we've got this rightabout here correlatingwith right up here. don steeples:if this was causedby a true earthquake then the amount of displacementis such that the earthquake would have had to beensomewhere up in the vicinityof richter magnitude seven. you saw what a richtermagnitude seven did in kobein japan in january of '95. a magnitude sevenhere would clearlybe felt in denver and it would clearlybe felt in kansas city,omaha, places like that. narrator: no major earthquake has ever been recorded in nebraska but that doesn't mean the great plains is immune.
don steeples: there's a faultline that runs roughly fromomaha down through kansas down throughthe manhattan area and on down roughlyto oklahoma city and it's called thehumboldt fault zone. and it's had earthquakesup in the richter magnitudefive to five and a half range. if we can establishthat this was causedby an earthquake it's significant in terms ofearthquake risk throughoutthe mid-continent not just herein harlan county orsouthcentral nebraska. geology doesn't stopat political boundaries
and so it's a very naturalthing for us to move acrossstate borders from time to time. narrator: natural disasters don't stop at borders either. the republican river flows along the nebraska/kansas border. 60 years ago it flooded killing 100 people. by 1952 harlan county dam was in place taming the river. don steeples: i don'tthink that the idea ofa richter magnitude seven has probably beenfactored in out here. critical structures likedams and power plantsand that sort of thing could be affected bya richter magnitude seven.
narrator: the fault line's origin may be discovered through seismologic tests. okay, fire. don steeples: whatwe do is fire an 8-gaugeshotgun shell underground and that gives usa source of sound energythat goes into the ground. then geologic layersin the sub-surface serveto echo the energy back and we pick the energy backup then at the surface withthese things called geo-phones which are essentiallya low frequency microphone. we're seeing echoesfrom 500 to 2,000feet below the surface. so those echoes thatwe're getting off theunits in the sub-surface
will be able to tell uswhether there's a fault which may be relatedto old earthquakes. in terms of dataquality, it's excellent. in terms of what we'regonna' be able to sayabout the structures it's a little bitearly to tell yet but if there's oneof these old faultsthat's not active now but was active inthe last 20,000 years there's likelyto be others. we don't knowwhen the last oneoccurred for sure
we don't know whenthe next one will be. what we do know is thatevery day we're one daycloser to the next one. narrator: our cities and dams may not have been built in the same locations with the information that geologists have today. steve adams: the traditionalway of doing geology is youwould go out and bang on rocks and only have alimited view of whatyou're looking at. we saw somegeological structures that have never been mappedbefore down in southern mexico. one of 'em is anold ancient fault line
with a dam righton top of it. when they built that dam they didn't knowthere was a fault there because they couldn'thave a regional view. that's whatthe satellitedata gives you. narrator: at nasa's jet propulsion laboratory in pasadena, california scientists have developed a technique that transforms raw satellite data into an active three-dimensional landscape. we're here to learn alittle bit more about thekind of work that they do
so that we cantransfer that back to theuniversityof nebraska and do this kindof work ourselves. this is a wire frameview of the omaha scenethat we're working on. it's usefulfor definingwhat we can see the terrainwe can see and the general idea ofwhere we're going withinthe final rendition. this lets yousee things that youcan't normally see just by looking ata bunch of numbers
looking atjust raw data. steve adams: this isthe northern half of omaha. this is the missouri riverhere that we're flying up. here's eppley field andthen the northern partof omaha and the bluffs. one of the goalsof this project is to make thistechnology availableto the school children. instead of gettinga two-dimensional pictureout of a magazine or a textbook they get a three-dimensionalview of what the placesare they visit. not only on earth
but they can visitouter space planets, too. brian tolk: what i've gothere is a satellite imageof the sandhills of nebraska and what i'm doing here is defining a flight paththat as we're flying over we'll be able to see in 3-d --three dimensions what thesandhills look like. the students thatare living in theomaha/lincoln area probably haven'tall traveled out to thesandhills or seen it before. this is a neat wayfor them not to haveto leave the classroom. you get a good idea ofwhat that area looks like.
this is the crescent lakenational wildlife refuge. it's verydesert-like and at the same time,it kind of has a wetlandecosystem in the valleys. so what this helps usdo in three dimensions is see where the cutoffsare between theselusher, lower valleys and the dune tops orthe drier upland areas. the sandhills is aregion that's proneto environmental damage and it loses itsstabilized state so by usingsatellite imagery
you can see possiblypockets of trouble,so to speak. remote sensing by definitionis being able to studysomething without touching it. ready for two. narrator: due to the remoteness of the sandhills scientists created a replica of a crescent lake ecosystem near the university of nebraska at lincoln. researchers are watching the sandhills wetlands for potential environmental damage. each plot has a singletype of vegetation
that is found commonlyin wetlands in this area. and we're collecting spectralinformation off of each canopy. one of the sensorsthat's feeding us data is pointingup at the sky and it's measuringthe amount of incomingenergy to the plant canopy and then the other ispointing into the canopy and it is measuringbasically all of the energythat's reflected back out or the energy that's notbeing used by the plants. don rundquist: thespecies that we havegrowing here at mead
are species that arecommon to the sandhills. if you lookat wetlands i think the numberis 6% worldwide in terms oftotal land area. now the reasonwe're interestedin those wetlands is because theyare a part of thegreenhouse gas scenario. they producecarbon dioxide. the marshes are -- orhave been implicated inthe production of methane and both of theseare trace gasses.
that is they area part of the globalwarming equation. the way this works isthat they are very efficientabsorbers of solar radiation so, for example,the more methane youhave in the atmosphere the moreheatingyou have. but these areimportant ecosystems because they doassist us with thingslike flood control and waterpurification and the habitatconsideration. narrator: to many the sandhills landscape
is a symbol of the great plains stability. jim swinehart: peoplehad thought that they'danswered everything. this is pretty simple. it -- the sands camein 20 or 40,000 years ago and formed the dunesand that was it. narrator: but to geologist jim swinehart hidden beneath the landscape is evidence of a restless prairie. jim swinehart:i think that it's suchan incredible landscape. it changesso much.
i was doingother things but i kept comingback to the sandhills. it was kind of likea magnet, you know,drawing you back. it is a unique placein the united states. this sort of paradoxbetween the dry dunesand these wet meadows. this is a swamp. it's perennially wet. the bulk of all thepeat known in nebraskaoccurs in the sandhills and mostly incherry county.
peat only forms where oxygen isnot available to essentiallyoxidize or burn the plant. so in an area that'scontinually wet you can start tobuild up organic matter. now it's gotta' staywet for a long time. if it driesout at all then itdecomposes. narrator: swinehart and crew have taken a core sample from 20 feet below the surface. and the peatdown at this end
it's no longerreally peat. it's been degraded tothis greasy black muck. narrator: between the layers of black muck sandy subsoils are locked in time leaving behind a warning. this isdefinitely sandy and there's peaton either side of it. we got dates rightbelow the sand ofaround 900 years ago. and that ties in withwork in other partsof the united states particularly thewest coast that says
somewhere right around900 years ago fora couple hundred years was a fairly majordrought throughout thecentral and western u.s. so we think thisis recording a significantperiod of diminished rainfall in the lastthousand years. it was dunebuggytime out here. announcer: the earth is not the good earth to man without rain. rain for the earth. rain to bring up the falling water table. rain to make crops grow.
rain for the grass that ties the earth into place. when the wind clouds gather nothing holds down the soil. jim swinehart: how severe aperiod of drought does it taketo destabilize this landscape? in the '30s -- the droughtof the '30s which is the mostsevere that we've hadin the last 100 years the '30s drought offive to six yearswasn't enough. again inthe spring
that grasswill be gone. that'll just be -- andall the sides will benice and wind-whipped. narrator: blow-outs are a common sight in the sandhills. to swinehart, they are a sign that the sand dunes are slowly moving. jim swinehart:there's too much wind there's too much sand and there's not enoughgrass a lot of the times. so bingo, you getthis scene here. you need three thingsto have dune sands move.
you gotta' havethe sand available. you gotta'have wind and you haveto have mostly anabsence of vegetation because sand onlymoves by bouncing. just get rid of someof this vegetation and we'll havea great sand sea. geologists can comefrom far and wide tostudy active sand dunes. we wouldn't beraising much cattle. so given that
i'll -- we'llgo for the cattle. we got plentyof other sanddunes around. mmmmmm,smells earthy. if we hit a drought like --it looks like happened maybe800 or a thousand years ago that might have lastedfor a hundred years no amount of good rangemanagement is gonna' protectyou from losing all your grass. these duneswill definitelybecome active again but i don't know ifthat's within 50 yearsor 500 years or 2,000. narrator: the sandhills' drought record
proves that the earth's climate can change dramatically over time. drought may not happen in an instant like an earthquake or volcano but it can be just as devastating. jim swinehart:by looking at the past we can get an idea of howrapid this system of dunes andwet meadows and prairie grasses how fast that couldchange on its own terms without humans throwingin their two cents worth. we're findingout that nebraska's avery, very dynamic place.
and you can lookat that out here and say thereisn't much there and you ignoreuniverses within that. there's just a lotof complexity out there and it tiesto everything. hannan lagarry:science is a slow process. it takes hundreds ofpeople hundreds of yearsto accumulate the information but then the insightsgained from that help us manage ourrainforests, our savannahs,our prairies, our woodlands.
don steeples: when i tookmy first geology course i realized that everytime you break a rock open you're seeing something thatno one has ever seen before. hannan lagarry: allthese things that welearn from the past and how we can sort ofinfluence the outcome ina direction we'd like. david moody: our futuregenerations are going tobe very unhappy with us if we haven'tdone all we could do and there's nothing likethe present to do something. captioning by
nebraska captioning centerlincoln, nebraska
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