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that was as nothing—well； as paratively little—pared with whatmay await tokyo。
tokyo has already suffered one of the most devastating earthquakes in modern times。 onseptember 1； 1923； just before noon； the city was hit by what is known as the great kantoquake—an event more than ten times more powerful than kobe’s earthquake。 two hundredthousand people were killed。 since that time； tokyo has been eerily quiet； so the strainbeneath the surface has been building for eighty years。 eventually it is bound to snap。 in 1923；tokyo had a population of about three million。 today it is approaching thirty million。 nobodycares to guess how many people might die； but the potential economic cost has been put ashigh as 7 trillion。
even more unnerving； because they are less well understood and capable of occurringanywhere at any time； are the rarer type of shakings known as intraplate quakes。 thesehappen away from plate boundaries； which makes them wholly unpredictable。 and becausethey e from a much greater depth； they tend to propagate over much wider areas。 themost notorious such quakes ever to hit the united states were a series of three in newmadrid； missouri； in the winter of 1811–12。 the adventure started just after midnight on december 16 when people were awakened first by the noise of panicking farm animals （therestiveness of animals before quakes is not an old wives’ tale； but is in fact well established；though not at all understood） and then by an almighty rupturing noise from deep within theearth。 emerging from their houses； locals found the land rolling in waves up to three feet highand opening up in fissures several feet deep。 a strong smell of sulfur filled the air。 theshaking lasted for four minutes with the usual devastating effects to property。 among thewitnesses was the artist john james audubon； who happened to be in the area。 the quakeradiated outward with such force that it knocked down chimneys in cincinnati four hundredmiles away and； according to at least one account； “wrecked boats in east coast harbors and 。
。 。 even collapsed scaffolding erected around the capitol building in washington； d。c。” onjanuary 23 and february 4 further quakes of similar magnitude followed。 new madrid hasbeen silent ever since—but not surprisingly； since such episodes have never been known tohappen in the same place twice。 as far as we know； they are as random as lightning。 the nextone could be under chicago or paris or kinshasa。 no one can even begin to guess。 and whatcauses these massive intraplate rupturings？ something deep within the earth。 more than thatwe don’t know。
by the 1960s scientists had grown sufficiently frustrated by how little they understood ofthe earth’s interior that they decided to try to do something about it。 specifically； they got theidea to drill through the ocean floor （the continental crust was too thick） to the mohodiscontinuity and to extract a piece of the earth’s mantle for examination at leisure。 thethinking was that if they could understand the nature of the rocks inside the earth； they mightbegin to understand how they interacted； and thus possibly be able to predict earthquakes andother unwele events。
the project became known； all but inevitably； as the mohole and it was pretty welldisastrous。 the hope was to lower a drill through 14；000 feet of pacific ocean water off thecoast of mexico and drill some 17；000 feet through relatively thin crustal rock。 drilling froma ship in open waters is； in the words of one oceanographer； “like trying to drill a hole in thesidewalks of new york from atop the empire state building using a strand of spaghetti。”
every attempt ended in failure。 the deepest they penetrated was only about 600 feet。 themohole became known as the no hole。 in 1966； exasperated with ever…rising costs and noresults； congress killed the project。
four years later； soviet scientists decided to try their luck on dry land。 they chose a spot onrussia’s kola peninsula； near the finnish border； and set to work with the hope of drilling toa depth of fifteen kilometers。 the work proved harder than expected； but the soviets weremendably persistent。 when at last they gave up； nineteen years later； they had drilled to adepth of 12；262 meters； or about 7。6 miles。 bearing in mind that the crust of the earthrepresents only about 0。3 percent of the planet’s volume and that the kola hole had not cuteven one…third of the way through the crust； we can hardly claim to have conquered theinterior。
interestingly； even though the hole was modest； nearly everything about it was surprising。
seismic wave studies had led the scientists to predict； and pretty confidently； that they wouldencounter sedimentary rock to a depth of 4；700 meters； followed by granite for the next 2；300meters and basalt from there on down。 in the event； the sedimentary layer was 50 percentdeeper than expected and the basaltic layer was never found at all。 moreover； the world downthere was far warmer than anyone had expected； with a temperature at 10；000 meters of 180 degrees centigrade； nearly twice the forecasted level。 most surprising of all was that the rockat that depth was saturated with water—something that had not been thought possible。
because we can’t see into the earth； we have to use other techniques； which mostly involvereading waves as they travel through the interior。 we also know a little bit about the mantlefrom what are known as kimberlite pipes； where diamonds are formed。 what happens is thatdeep in the earth there is an explosion that fires； in effect； a cannonball of magma to thesurface at supersonic speeds。 it is a totally random event。 a kimberlite pipe could explode inyour backyard as you read this。 because they e up from such depths—up to 120 milesdown—kimberlite pipes bring up all kinds of things not normally found on or near thesurface： a rock called peridotite； crystals of olivine； and—just occasionally； in about one pipein a hundred—diamonds。 lots of carbon es up with kimberlite ejecta； but most isvaporized or turns to graphite。 only occasionally does a hunk of it shoot up at just the rightspeed and cool down with the necessary swiftness to bee a diamond。 it was such a pipet