| Show I I i Chance of Having I I Earth POSSIBILity NOT REMOTE BY FRED J J. J PACK A. A M. M Deseret Professor of Geology i at the University of Utah Ut-ah I What are the probabilities I of Salt Lake being visited by earthquake disturbances This question has been asked because of an anI allusion to the matter by the writer in the course of a pu public lecture given a few nights ago Atthe At Atthe Atthe the outset it should be stated that we are not at all apprehensive of any trouble yet such an occurrence could be easily accounted for within our vicinity It 11 TV will be e remembered that disturbances are generated b by volcanic or b h by the slipping of or block locks l In the first t ca case e thoy they Hr are often octen V-I V vec ery violent near pear the point or origin but iut are field om destructive at distant points In other words voids the o orco p partakes er iery much of the tho na- na tuie ture ui a of an explosion ion which often reCO re- re CO I Oi lIIl In c T CHANCE OF HAVING EARTHQUAKES HERE Continued from On- On Page Inge One suits In extreme disaster over comparative comparatively comparatively small areas arios Some of or the tho most violent earthquakes on r record corll were duo dun to this cause The second generative force Coree that of ot movement Is in the main re responsible responsible responsible re- re for disturbances extend extending Ins Ins- over large areas The San Francisco earthquake which was set up b by this cause was recorded in considerable detail letaH as far awa away as ns Washington D.C. D.C. D. D C. C A word In regard to the origin of oC movements Tho The earths earth's n K etc r t I ts Is receiving heat from rom two tho rc B tho part pure comes cornea I from tho the sun gun and the smaller part from room the earths earth's interior Tho The fact I appears to be established that the earth is slow slowly cooling off oce and that In remote geological times its I temperature ure was er very much higher than at present of nr Contraction In consequence CO of the contraction duo to cooling tho the surface has suffered suffered suf suf- rrell profound crumpling and assuring assur- assur Ing The slipping of ot these enormous earth blocks s one upon another nother Is not continuous the generative force Is cumulative and anil when sufficient energy has hns been gathered to overcome the re resistance resistance re- re the time slip sill takes place glace with al almost almost almost al- al most like lightning rapidity Time The seismic waves set up b by a n. slip of oC a afew afew afew few feet Ceet or even cn a 0 few Inches are sufficient suf suf- to cause use great devastation At times this slipping or faulting extends directly to the surface and tWit makes It Itself itself it- it self visible In n fissures and escarp escarp- ments IH When n once a plane plan of ot weakness has been heen established It becomes easier casler for subsequent movements to tal take e place along that plane In consequence of the condition the time total displacement along alon- a L single plane pline often oCten becomes enormous One of or these great s-reat fault es escarpments escarpments escarpments es- es extends along the western face of ot tho time Wasatch mountains from Crom Nephi on th time tho south to Willard on the north In the vicinity of ot Salt SnIt Lake Lako City It passes along alons- time tho bench n l lands 9 lust hl i m l ro 0 r D n n 1 l e s It sit 1 g t to l a H n if b 1 the tho northwest along the foothills and then passes to the north along the line lino of or the Warm harm springs and Hot springs s. According to tho the Held field examinations this enormous fault tault has an a aggregate vertical displacement of or Cull fully seven miles It must not be bo thought that this almost throw is the result of a single sins action It I is without doubt ma made o up of or innumerable smaller one ones I Just when this Wasatch faulting began began be h.- gan cannot bo stated othor other than In lu th the most general terms Tho best that I Ican can be said is that it began bes-an awn away back In n mid geologic times An 0 I Important The rho more Important question to us however is this Will win there be bo more inure faulting along this line In tho the future Our answer must be bo more Indefinite still This much can be said however that hat complete evidence exists of vcr very recent movement mo and that too of no gentle JentJe type Near the tho mouth of oC the Cottonwood canyons canons tho time faulting shows a 0 dl displacement placement of ten to fifty fitly feet Near the Hot springs s to the north of the tho city the disturbance was equally as great S The Time seismic activity generated b by this throw has likely lately not had lad a parallel In historic times timeR The writer has hns elsewhere stated that should a Q repetition of ot this occur there would not be bo a 3 hen house left lett standing In n Salt Lake City Is a 0 repetition likely to come conic This wo cannot answer It mo may and It ma may not lot Human hh history tor Is so 80 brief brIer in ln comparison with tho time time In which nature hn has han to to do her work that gen con mn may pass away between n two successive o disturbances Further the recent disturbance may mav be he th the final one or again others may Jay be yet be before before before be- be fore us and perhaps not remotely dis dis- I tant tanto Let time the good s people of ot Salt SnIt Lake City rest reat In peace It will be bA time to cro cross s th the river If wo we ever ver reach rench lt It I The above t Int Interesting article by Professor Pack was written at the re request request re- re quest of or The Republican It having ha be- be Ih that Professor ProCessor Packs Pack's views on tho the question would Interest ever every person person per per- son ion in Utah Utah Editor I |
