IN ONE OF professional acts before Einstein e a sbut gloo a book by a geologist named Citled Earting Crust: A Key to Some Basic Problems of Earteady demolition of t continents ion. In a tone t all but invited to join olerant c a fe correspondence in sain continents.” It Sout be fitted toget is evenclaimed t rock formations on opposite sides of tlantic match.”
Mr. ions, noting t ts K. E. Casterand J. C. Mendes ensive fieldlantic and ablision t no sucies existed. Goodness knocropsMessrs. Caster and Mendes , beacuse in fact many of tions onbotlanticare t just very similar but the same.
t an idea t fles of o propounded in 1908 by an amateur Americangeologist named Frank Bursley taylor. taylor came from a raints to pursue unconventional lines of inquiry. ruck by ty in slines of Africa andSoution tinents ed—presciently as it turned out—t togetinents could up tain co producemucoo crackpot to merit seriousattention.
In Germany, aylor’s idea ively appropriated, by at named Alfred egener, a meteorologist at ty of Marburg. egenerinvestigated t and fossil anomalies t did not fit comfortably into tandardmodel of Eartory and realized t very little of it made sense if conventionallyinterpreted. Animal fossils repeatedly turned up on opposite sides of oceans t oo o so Australia?
ical snails turn up in Scandinavia and Ne,did one account for coal seams and otropical remnants in frigid spots likeSpitsbergen, four someed therefrom warmer climes?
egener developed t tinents ogeto mingle, before tinents apart and floated off to t positions. All t togetsteinente und Ozeane, or tinents andOceans, break of torld ar in time—in Engliser.
Because of t attract mucice at first, but by 1920, quickly became a subject of discussion.
Everyone agreed t continents moved—but up and do sideical movement, knoasy, ion of geological beliefs for generations,to extbooks o my o before turn of tury. ted t as tenEart ing oceanbasins and mountain ranges. Never mind t James ton anysucatic arrangement ually result in a featureless sps. trated by Rutury, t Earts —mucoomuco allo of cooling and sed. And any tains sributed across tently t, and of more or less t by t t some ranges, like time unately, Alfred egener t geologists .
For a start, ions questioned tions of tive o generate , but egener eorologist, for goodness sake. A remediable deficiencies.
And so geologists took every pain to dismiss tleions. to get around tributions, ted ancient “landbridges” ime, a land bridge lantic. ancient tapirs ed simultaneously in Sout Asia a land bridge oo. Soon maps of preoricseas solid o Europe, fromBrazil to Africa, from Sout Asia to Australia, from Australia to Antarctica. tive tendrils only conveniently appeared o move aliving organism from one landmass to anot t leaving atrace of tence. None of ted by so mucual evidence—not it ury.
Even land bridges couldn’t explain some trilobite t o only on one side. Noone could persuasively explain o cross tileocean but to find its rilobite found in Europe and t but noe as 1964 ical difficulties.”
to be sure, egener made mistakes. ed t Greenland is drifting by about amile a year, o believe in o accept t massive continents some, like a plo motored ts.
It ermine ted a possible ist to understand tradioactive ion currents o slide continents around on tial textbook Principles of P publisa continental drift t s fundamentals t prevails today. It ill a radical proposition for time and icized, particularly in ted States,o drift lasted longer tted, anyevident sense of irony, t ed s so clearly and compellingly tstudents migually come to believe trike>ｈtｔ<a href="p://</strike>" target="_blank">p://</strike></a>
Elseious support. In 1950, a vote at ting of tision for t of Science s about noinental drift. (er citedtragically misled Britiss imes inental drift; in mygeological bones, so to speak, I feel tastic one.”
Continental drift entirely support in ted States. Reginald Daly of, but ed t t, and ended to be considered interesting, even a toucoo exuberant for serious consideration. And so most American academicsstuck to t tinents positions forever and ttures could be attributed to someteral motions.
Interestingly, oil company geologists if you ed to find oil youo allo of surface movements t e tectonics.
But oil geologists didn’t e academic papers; t found oil.
t no one o resolving. t ion of . Every yearEarterial—500 million tons of calcium, forinstance—to tiplied te of deposition by t produced a disturbing figure: t ts on ttoms—or, put anottoms sops. Scientists dealt possible way.
t. But eventually t w no longer.
In ton University mineralogist named in ctack transport ser, ate ins it could equally ificpurposes and never sc off, even sea, even in t of battle. irely unexpected. If t, as everyone assumed, ted s, like ttom of a river or lake. But t t silts. It ed s t s after an earlier Princeton geologist named ArnoldGuyot. All t o take part in, and put sucs to theback of his mind.
After turned to Princeton and tions of teac teries of tinued to occupy a space in s. Meaned surveys of tiest and mostextensive mountain range on Eartly—underer. It traced a continuous patitc Iceland, youcould follo doer of tlantic Ocean, around ttom of Africa, and acrosstralia; t angled across ting up t coast of ted States to Alaska.
Occasionally its er as an island or arclantic, ance—but mostly it y sea, unknoed. s brancogetended to 46,600 miles.
A very little of time. People laying ocean-floor cables in teentury tainous intrusion in tlantic from t tinuous nature and overall scale of tunning surprise. Moreover, it contained p couldn’t be explained.
Dolantic ridge —up to a dozen miles s entire 12,000-mile lengto suggest t tting apart att bursting out of its s ion, but t be denied.
t te young at tlanticridge but gre to t or . ter and realized t t ral rift, t as necame along belantic floor ively ts, one carryingcrust to tohe process becameknown as seafloor spreading.
reacs journey at tinents, it plungedback into tion. t explained . It urned to t also explained o be older t175 million years, al rocks en billions of yearsold. No took to travel tos iful t explained a great deal. ed ant paper, imes t isn’t readyfor a good idea.
Meanartling findingsby dra of Eartory t had been discovered several decades earlier.
In 1906, a Frenc named Bernard Brun t’s magnetic fieldreverses itself from time to time, and t tly fixed incertain rocks at time of tiny grains of iron ore to time of tion, taypointing in t direction as t tic poles time of tion. For years ttle more ty, but in trick Blackett of ty of London and S. K. Runcorn ofty of Nele studied t magnetic patterns frozen in Britisartled, to say t, to find ting t at some time in tant pastBritain s axis and traveled some distance to t s moorings. Moreover, t if you placed a map ofEurope’s magnetic patterns alongside an American one from t togetly as tter. It was uncanny.
too.
It finally fell to ty, a geop named DrummondMatte student of o drarands togetic studies of tlantic Ocean floor, trated conclusively tted and t tinents ion too. An unlucky Canadian geologist named La time, but couldn’t find anyone to publish his paper.
In oldions make interesting talk at cocktail parties, but it is not t of t ougo be publisific aegis.” One geologist later described it as“probably t significant paper in to be denied publication.”
At all events, mobile crust ant figures in ty in 1964, and suddenly, it seemed, everyone . ting agreed, erconnected segments ely jostlingsaccounted for muc’s surface behavior.
tinental drift” ly discarded t ion and not just tinents, but it took a tle on a namefor ts. At first people called tal blocks” or sometimes “pavingstones.” Not until late 1968, ion of an article by ts in ts receive tes. ticle called tetectonics.
Old ideas die everyone ruso embrace ting neot popular and influential geological textbooks, trenuously insisted t plate tectonics as it edition ion and seafloor spreading. And in Basin and Range, publised t even t in eigill didn’t believe in plate tectonics.
today Eart to tes (depending ony or so smaller ones, and t directionsand at different speeds. Some plates are large and comparatively inactive, otenergetic. tal relationso t sit upon te, for instance, is mucinent isassociated. It rougraces tline of tinent’s ern coast (ive, because of te boundary), butignores tern seaboard altogetead extends lantic to t do tectonically of te event is no plates.
tions bet o beinfinitely more complex tan, it turns out, taco Noraten Island, but only a corner, isEuropean. So is part of Nes beacsnearest kin tisantially American. Some of ton Range of Antarctica, it is t, may onceo tern U.S. Rocks, in s, get around.
tant turmoil keeps tes from fusing into a single immobile plate. Assumingtinue muc present, tlantic Ocean il eventually it is muc off and become a kind of Madagascar ofto Europe, squeezing terranean out ofexistence and ting up a cains of y running from Paris toCalcutta. Australia o its nort by some isto Asia. ture outcomes, but not future events. ts are inents are adrift, like leaves on a pond. to Global PositioningSystems Europe and Norting at about to long enougo San Francisco. It is only ty oflifetimes t keeps us from appreciating t a globe and inents as t one-tentof tory.
Earts in ectonics, and ery. It is not simply a matter of size or density—Venus is nearly a ts and yet ectonic activity. It is t—t is really not—t tectonics is an important part of t’s organic and er James trefil it, “It tinuousmovement of tectonic plates on t of life on eartst tectonics—ce, for instance—ant spur to t of intelligence. Otings of tinents may least some of tinction events. InNovember of 2002, tony Dickson of Cambridge University in England produced a report,publisrongly suggesting t tionsory of rocks and tory of life. Dickson establis tion of tered abruptly and vigorously tt ten correlate ant events inbiological ory—tburst of tiny organisms t created t, t causes try to cically from time to time, but tting of ocean ridges .
At all events, plate tectonics not only explained t from France to Florida, for example—but also many of its internalactions. Eartion of island cions ofmountains, tself—tter t directly influenced by ts, as McPed,found tion t “th suddenly made sense.”
But only up to a point. tribution of continents in former times is muclyresolved t people outside geopextbooks give confident-looking representations of ancient landmasses imes based on conclusions t don’t altogetory of Life, species of plants andanimals from t ly o be w.
tline of Gond connecting Australia, Africa,Antarctica, and Sout on tribution of a genus ofancient tongue fern called Glossopteris, eris s of t ion to Gondroubling discrepancy inues to be—mostlyignored. Similarly a triassic reptile called Lystrosaurus arctica allto Asia, supporting tion betinents, but iturned up in Soutralia, inent at time.
tures t tectonics can’t explain. take Denver. It is, aseveryone kno rise is comparatively recent. of an ocean bottom, many t lo ts are not fractured or deformed in tes, and anyoo far from te edges to besusceptible to tions. It oraise a ruck at te end. Mysteriously and over millions of years, it appears tDenver oo, ion ofit a t any knoed tectonic activity. Australia, meaning and sinking. Over t100 million years as it ed nortos leading edge . It appears t Indonesia is very sloralia do. Notectonics can explain any of this.
Alfred egener never lived to see ed. On an expedition to Greenland in1930, out alone, on ieto c a supply drop. urned.
er, frozen to deat and liest, but about a yard closer to Northe day he died.
Einstein also failed to live long enougo see t , Princeton, Nealdrift theories was even published.
tectonics tPrinceton at time, and of udents way.
As for geology itself, its cataclysms begun, and it art the process.
PARt IV DANGEROUS PLANEttory of any one part of tsof long periods of boredom ands periods of terror.
-Britis Derek V. Ager