SEISMOLOGY. 391 



consideration, but to the readiness of American scientific bureaus and institu- 

 tions to advance research even when not in the direct line of their immediate 

 program. 



Not only has the full program been adopted as proposed, but work has been 

 begun and no inconsiderable progress made in each of the directions con- 

 sidered. This progress may be reported under the several headings of the 

 proposal of last year, as follows : 



1. Study of Geological Formation along the California Fault Lines. 



Work on California fault-zone geology was begun by the appointment of a 

 local subcommittee in California under the chairmanship of Professor Bailey 

 Willis, of Stanford University. Associated with him were Professor A. C. 

 Lawson and Dr. Ralph Arnold, members of the Advisory Committee, Mr. 

 Fred P. Vickery, of the Southern Branch of the University of California, 

 and Mr. L. S. Noble, of the U. S. Geological Survey. To this subcommittee 

 was intrusted the task of preparing a plan for a thorough geological study of 

 the faulted regions of California. Such a plan has been prepared and work 

 was begun at once by the representatives of the Geological Survey, aided as 

 opportunity offered by the other members of the committee, and in particular 

 by Chairman Willis. Sections of the San Andreas fault, which is perhaps the 

 most important zone of weakness, were assigned to different members of the 

 subcommittee, and some of these have received thorough study during the 

 first year. 



Perhaps the first tangible result of this study will appear before the end 

 of 1922 in the form of a fault map in which these zones of structural weakness, 

 so far as known, will be laid down. It can not make any pretension to com- 

 pleteness, in view of the immense territory involved and the short time 

 available for the undertaking, but perhaps the very gaps themselves will 

 stimulate interest in its completion. A special report of the chairman of 

 the subcommittee on Fault-zone Geology is appended. 



2. Surface Displacements. 

 The U. S. Coast and Geodetic Survey has been much interested to under- 

 take an accurate triangulation of those regions of California which are partic- 

 ularly subject to earth movements, and with the support of such influential 

 organizations as the Commonwealth Club of San Francisco, the American 

 Institute of Mining Engineers, the Seismological Society of America, and 

 Senators and Representatives from California, who have shown much interest 

 in the economic phases of the proposed studies, has obtained an appropriation 

 of S15,000 for the fiscal year beginning July 1, 1922, with which to inaugurate 

 this work. Arrangements were complete for beginning the work as soon as 

 the funds were available, and a system of triangles is now being established 

 extending from San Francisco Bay across the important zone of movement of 

 1906 to the older formations of the Sierras at Reno. This work is expected 

 to be completed before the snow appears in the mountains. It will be fol- 

 lowed in the spring by further work in a locality to be selected later. It is 

 the purpose of the Director of the Geodetic Survey to apply to this task the 

 most precise methods hitherto developed in order that the closest possible 

 control may be established of the important landmarks in this zone of move- 

 ment. 



