Blinst Mtg Notes, 29 Dec 51 on whether gauges cre dcubled up to cover the higher range. The positions shown in the table were chosen. As noted, four of them already have recording stations. LASL 1s also working on methods for making this measurement. It will be decided in the near future as to which grow will actually perform the work. E. Earth Motion Studies It was originally proposed to measure two components of acceleration at each of the stations provided fcr pressure-time, and in the event that a strain gauge is devised to measure set as a fumction of time per unit length, this would be included. (It is not known whether or not a third transverse component will be observed--it was on Jangle.)} Cox explained that since the proposal was made, they had about decided not to attempt direct displacement and velocity measurements,since they could not quite see how this was to be done, but simply to measure acceleration as a function of time and try to compute the others from this if they are required. Admittedly, this latter is a nasty job, but 1s possible in theory. They do have inatru-; ments which will measure an acceleration of 100 g's. This measurement will be done in the hope that one can predict what would happen to other types of ground from measurements at Eniwetok. There is a reasonable doubt that this is possible; in any event one would feel safer with three components to work with. Sandia agreed that if the strain gauges did not look feasible, they would attempt to devise some ovher wethod to measure displacement in at least one or two places. Because of the fact that extrapolation to other terrain does look so difficult, it was suggested that only a minimal coverage be provided. Murphey pointed out that one could be sure the structures people would want to attempt to tie this in with the surface shot data, whether or not it is meaningful, and would nct be happy with two or three points. Also, the information may be useful for future tests of bigger bombs at Eniwetok. The stations indicated on the table were chosen. The choice of one or both of the first two positions was left questionable, since there Was scme dissensicn as to whether a gauge on the causeway would mean any(The gauge would actually be installed in the coral reef rather thing. than on the causeway.) The apparatus will be similar to the usual accelerometer, and will be mounted solidly to the ground. ‘ Incidentally, Zadina stated that the acceleration on Parry wes from 0.05 to 0.3 gts, assuming no channel or focussing effects. be to likely F. In-earth Pressures The proposal here was to make pressure measurements at three levels in the earth (at something like 20 --50 ft depths), in order to assess