Show An Earthquake Expert Talks The Thc following letter is fro from m time the U. U S. S Geological Survey at Baltimore Maryland in answer to letters letter of A. A H II Thiessen the U. U S S. S Weather Ye ther director at Salt Lake City It is written by hy one OtiC of the most t noteworthy earthquake e c x- x ports in th the world Mr l r. r A. A H. H Thiessen Sec Dir Weather Bure Bureau Salt Lake Lak City Utah Dear Sir I was very much interested in the report you sent me mc from Mr 1 M M. M. M I. I Smith regarding the subterranean subterranean sounds in ill his locality There are many places sc scattered over over the world where s sounds l of this kind are fr frequently heard and many attempts have been made to explain their origin The Thc most probable explanation is I think that they are clue ie dieto ue to a acry very cry slight slipping or the formation of very small fractures fractures frac frac- tl tures res in the underlying rock causing vibrations which are rapid enough to affect the sen senses es as sound The experiences experiences experiences exper exper- which Mr lr Smith Inith mentions mentions men men- Hons that th the sounds began about four years ears a ago o and have ha not alway exist existed d in that locality also agrees with experiences experiences ex ex- elsewhere In some places sounds of this kind lasted lasted last last- ed for a few fe years and dis dis- appeared When earthquakes occur which are stron strong enough to he be felt they t are very apt to tobe tobe tobe be accompanied accompanied by sounds and the sounds occur without the earthquake this probably means that the earthquake earthquake earth earth- quake has really occurred but it is s so feeble it c can n not be felt At Ea East t Haddam Conn noises have been heard ever since the country was settled b by white lute men then and Indians rep reported the noises earlier still but they do not nots s seem em to ha have hae e give risen rise t to on any important earthquakes It might be he a good thing if lI Mr r. r Smith m would keep Q as careful careful careful care care- ful a record as IS he lie can cairo can of the time sounds noting the date time and inte intensity it and ami so 90 far n ae as possible tl the direction ct o w f froth from which they s seem m to come He might also coll collect ct from people li lin living n in the nei neighborhood hood data regarding the time direction of the sound and thus more accurately accurately determine its origin This is no not very easy a as it is usua usually difficult to determine whence whence the sound conies conics A series of o observations sen of this kind when studied might yield some some results results results re re- but lout it itis is a little difficult to know w beforehand just what might come out of it There is no fund available for sending sending- an expert or a seismograph raph to Mr Smiths Smith's region I J doubt if an expert co could td Bud find out much and I rather imagine the shocks are Hrc so very ery slight that probably seismograph would not record them I am n returning turning to you i Mj t Smiths Smith's letter after n k- k irI t a copy cop of it for Ill my record Sg L I-L HARRY HARI RrY Y FIELDING G record REID EID |