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About The west shore. (Portland, Or.) 1875-1891 | View Entire Issue (Jan. 1, 1879)
THE WEST SHORE. January, 1879, SCENES IN THE Hli. II KIEKKA. The following interesting article ou glaciers, by J. 0. lmmon, ii Ulten (nun the columns of II,'' Mimmj nml Srimlifit I'rru: out ikiui un tiikik raw. Nowhere oIm in ( 'aliform are glaciers more tally represented than hers around the haaei of this II group g half a doMtl peaks. It ia not o aurpneihg that the much loftier Whitney group t" the aouth, nor the great douiee of liana ati)l iihle northward, scarcely retain an active glacier, when we uotiaidcr the character of their rock, reddish jiorphyiy, greciiatoiio ami slates, all g.l alx.ihauU of aolar rays. The colli, gray granite ami silvery ipiarl of l.yell, added to Uie interior location of the group, condense the inoiature out of the over flowing wimln for a longer nod of the year, to fall iu copioua ahowen of allow on their plateau, theu to erys- talliae 1.. MM, n hanletiing to lielili of ioo called Mm at (llnrr, from whence glacier emerge, griailuig thoir way t.. the plain, rnorr tii fait, tiux m orkiin Tho. Afrri ilr (Hart are ribbed from upMr to lower Mile with hard mow, the lowsat eml Die largest between each mlge, in the wanneat hour of aummer ilay, there (Iowa the daily ineltol mow, hllmg the rracka that occur alwayi 111a maai of ice un every change of teuiiera lur. I town each oanyoii of every eak, where favored by ahadr, Mow. a (rnaen river, a glacier, On lU I a. regularly distributed, are rocks of all ..... MM jiartly covered with the ridgea of " ntm glaciera move alowlv down Ik. owvona, which the) e.actly till, to the level of the melting N.int at the preaent time in tlua region at an .wvalion M atmul 1,QQ f,t Arrived .oe meiung line the J ,,-r abruptly ler oeer ire ipice, aemi circular outline. 111 irom ,u edge, one after another, ui uie r. a 1 . lormitig a curve ..I I. I ...I I . L. . . Mm. a- a moraine. heae morainea r. ... one 10 two mile, long 11, their aweei; la eurv. and .VI feet high. following down U10 renmx, it ia found to he .n...,. on in. 11..IU.111 ami aidea, with no ahan ko.lt. In ila .......... ..... ..-1 ... A . . . T . ' l"'1"1" m ... . awr MM At mUrvala, drip, ..., ,.,, taaae are louml in or near the 01 ne ravine. Al , . J I I ... ) , .,. rw.ine maaer ooi,t, )u.t over the Iwn. . (,,,, , rarlner ,, when the i.l.iu i. .1. ra. in. )n.n. with other. U , , j alley. stre.uj.ly rwgeler It contour. ,. .harp k't . 'till , f r k .Mi at.la. ...I. r a . h ok..te. . rwm. """""it ' , 7. "vw MMH one, i w do nvera. MB urn 10 gl t a Meat, IWIor. . ufmi.l u. mterpr.1 the. ,.h .4 u.r;.;ii7 eltlfi"1!1 "m 1 " i tmm n.ne Uie MM Hi aivrn to ..... i.-.l- - V .r .ii. muter, i, awaatV Th. ii,n ..( .k. ia r 1 . , iw lloWfk Z.r..TTJ. 7 " "'I- " Ihe prearn "I'-ad.all, draw. MMMnitl u.;,w zn: rfr : i . , - ", wnn innr W rf avaUnaJ. ..... rnorW Aa Um Ma. with iu .n, ,,.,.. i.i .. l . T. , " 7 " ." ""' ao.1 .lenudim- .,., Ul h.r.U al harvler Uie nl. Th. M'.way Ural, and, it may . .. I he., thai Injtwocii no Vowel uijj jjcu. wioiu uuw Mdattd much higher, but easier denuded rocks. At length the great icy sea receueu unni it became fenced into basins by the appearing mountain chains. In the weakest places chan nels were formed, and aa differences of level occurred, as reaiecU the basins, the resistance uf the sierra barriers catiaed tremendous pressure noil the nidus of these channels, aud the ice blocks squeezing through, often wrenched the toughest rocks from their ledges and hurled them upon the distant plain. Other rooks Buf fered the loss of crowns and angles and remain i.ilav as domes or bosses uixin the Hunks of the mountains, notably in tho region of Yo- semito, where they may be counted by the score, their scratched ami polinlicd surfaces recording at once the hight, strength, and direction of the ieo currents. At last the glaciieaqucous epoch wafl ended The waters were gathered into their future home, the ocean. 1 he dry land appeared strewn with debris for hundreds and thousands uf miles on each side of the mountain chains, while a warm atmosphere crept from the plains by degrees up the mountains, clothing them with vegetation. Next succeeded the wonderful phenomena of at.tmw. At lust glaciers were developed on a scale so rami as to lie scarcely conceived of now. 'heir work is denuding mountain rainreB aud snariieiiiiig Homes into pinnacles, as did thci narulit. the iev ae. hut. thi.v t.,.1 it. . ...... mt. i . j --I --- - j ... . ... . ferent manner, slow as the cycles of ages, silent uie molil ot the tomb. I heir DOWer m cuual to the destruction of the hiuhest mountains of the globe, and to the furrowing of the deepest loaemites oi inu plateaus. B AIX llltllISS WITH TIIK MKKH UK OLAQB Tl l I ... . . . inc.u in...e. oi ice, at nrst, stramled upon lateaua, afterwanl formed from mow fnlli no in an. ring localitius, are fixed to the earth, in niiier, tnougnout tbeir extent, liy freezing, 'crtain xitiU uf greatest cold arc developed. coinciding pndialilv with tho lowaat ..lae. M theiH. points the rock .m . h. I ii. ...I.. y the ice and form a fulcrum for ,k mum',. ...... eoiuoi., which win no examined soon akwl font! rwxk rirai, lei II no relllem iere.1 that ,.r...,l. wneu nirming, aisiut one ninth of its volume nocomi, when criishe.1 at a temperature be I. lo wmgeaia, over ami over auain Tl.ie.1 il,. t tk. i i . P - . ... luiui oi i . i . I . i , ,.,. , . ... 1 -" .o -in "i ui. moat powenul known, utterly irresist II. le. Now from the Haul of ST.at..a ,.t,i u. bwk.aUU .L.. r..l u T . . u vou luwruiu iirmiv clasiiod, the ice ex . y congealing, thaw ing, crushing and re gelation, an.l pral in every direction -renc. ung a.., taking the contiguous rocks with it, and rasping them upon those left iu ' HMU1A, Iim result i ,t i ii . ... i . .. . , - i i ... l , aj ni ami up. wanl of the maaa oi ice and oonacpiently the Mcavatrng of the crator lik. an, ,lthe.tcrs Z. r TTrJZT lhr,u " ompty. on Ue Mm of the mountains. Thi. counts al,. "fijl "' glacier's track, once ice ,,., ,, water toniiiug. oUciaRs at -woajk. Th. UlllMT n.1 .M. mi ' . , -ri -a- una s.w.Mul excavator Wk.tolw.T.'k"!''?. "I"'" Ihe greate.t amonntof preur. will K " ' e uim-inm ol rut re.i.1.,. i the final do...,! ,T l,"U,lc'. h'C uuw o, uh iruaen river. l tf UKU. The .V.kf.a tasaaaMll ,j i.i.- . imMjMM ,h., . ,:rL,-":'"rn",fi "" - w A ' - " t.nii hi . linn . l-i Z" - "ur " excav .i,," ." ' "nn. ao aoou u tl.. . ..TMmbU, fluent thawinp and frccalugs, Waiu, ... uuwu, are attended by expansion, crushing of ice and regulation, the latter of course attended with renewed ex pansion. The fulcrum or fixed point would change from side to Bide of the bottom seeking- i . -.i r . .. a uie loweab piuue, irom eoaeuu to season, or rattier from age to age. the result would be the scooping out of a crater of more or less depth . i i i a.. i -. , r .1 sioppou uoiy uy ine conouuon ot unchanged, low temperature reached at the bottom, gener ally several icct. nnens change to wanner temperature occurs (which rile will soon show ib sudden, and by several degrees at once), the ice is melted, and the ice-womb or fountain, becomes a deep clear glacier lake, or often, if in loose soil easily drained, remains empty. 1 hose lakes distributed along a ravine, show here daciers had their oriirin. or where nor. t inns of a flowing stream fastened on the bot tom, for a period, and proceeded to diurini wells upon the most gigantic scale, and with the most powerful yet simple of mechanical agonts, ice-expansion. The warmth of the atmosphere in a distinct stratum at the melting limit, causes an abrupt termination oi the glacier, while its now being unhindered in the center, is faster there ana causes the outward curve to its front, and this rain-bow curve determines the shape of the moraine of rocks dropped from its brow, added to those disgorged from its mouth below. 1 he regularity of form of the glacier bed re sults from the power of ice to remove obstruc tions, like an immenae furrowing flow, and itt graceful curves amty from the entering tribu tary glacier shows by the degree of deflection the size of the tributary a phenomenon never exhibited by water currents. Trains of rocks often seen, longitudinally dis posed upon a glacier, show the union of two or moro sli. li tributaries. Their rooks deposited upon the terminal moraine form nodules or heaps in the latter. When left M tlu by the sudden melting of the glacier, they form medial moraines : while those rocks carried outward to the side of the glacier form the third kiud, lateral moraines. Terminal moraines bcinir found deposit! t the brow of every precipice in the glacier's course, prove that the heat of the atmosphere has increased by intervals of several degrees at a time, not gradually a moat important deduc tion irom the study ot glaciers, bearing upon tho subject of climatology, the sudden with drawal aud introduction of different species of animals, and plants, etc If the increase of temperature was gradual no terminal moraines of immense size as now seen, would be formed, but the rocks would be scattered along the track of the receding glacier. i ne tew rocks tound ou the back ot a glacier, iu very slow movement, the bottom of it only moving in summer, the swiftest recorded motion being a Swiss glacier that only traveled 4.4UU feet in nine years, together with the often, immense hight of the terminal morainea, AO feet or more, all prove the necessity of vast periods of time required for their forma- uou. Finally the long, deep, glacier-carved valleys, like the famous ..somite tmv the orevalunce of glaciers of prodigoua aiae and power, plow- uk me piateaus ot the middle region oi ui. Sierra, down to a low point near the foothill", the melting line being met at their mouth at an el. vat io of only about 3,000 or 4,000 feet. ' MM Ml- BRCOMtNO WARtfin. From this brief atudy ol glaciers may k de duced a theory of the positive increase of the earth's atmosphere aa the ages have rolled by ( an increase which has advanced the melting point-33 KahuptheSierra, ".OOOoro.OOOfeet, ince the day of the great glaciers. At that 1" ii..., such alleys as Sierra and its sister, uow decorating the flanks of the Sierra north aud south, were either lakes imprisoned with ice, or complete ice-womb, the source of gl iers whose moraine have been scattered sine by thio ls from higher basin as their contents Were feed : while 1 1... r..i v.lt.u r California, nd the great basin of Nevada were cold, fr