Chapter 3 Discussion 3.1 PROFILES . the effect of the causeway and the deposition of the sand spit south and east of the crater are For discussion, it is somewhat more con- venient to present the results of these craters in the form of profiles derived from the cofitour maps, Figs. 2.1 to 2.4. These profiles appear as dashed lines in Figs. 3.1 to 3.4. On each of these figures the full line is a theoreti- clearly long-time developments which do not reflect the actual crater shape. cal line, used for comparison later. It will be observed on Fig. 2,1 that data were obtained along a number of rays in the Green- house Dog crater. Figure 3.1 contains these results as dashed lines, plotted at distances from Ground Zero, and at the various angles indicated by the array of points on Fig. 2.1. The crater is observed to be quite irregular w in shape, having a maximum depth apparently less than 3 ft. The existence of mounds in the Figure 3.4 is the crater profile from Ivy Mike derived from Fig. 2.4, which shows a maximum depth of 170 ft at first glance as the depth of the Mike crater. The interesting point is that the deep hole occurs some 350 ft from Ground Zero. The chgice of a pressure profile plot has been Figure 3.2 is the crater profile from Green- house Easy derived from the contour map of Fig. 2.2. This crater is fairly uniform and appears to be reasonably described as a conic section with a maximum depth of about3 ft, and a crater width of about 600 ft. Isolated elevations determined from the survey are shown as circles on this plot. Figure 3.3 is the crater profile from Greenhouse George andis fairly regular, considering the processes of erosion and deposition which have occurred since shot time. The high ridge just south of the crater (see Fig. 2.3) is known to have been filled in by bulldozers in order to isolate the lake from the lagoon. Similarly, made partly to emphasize this fact. From the relative uniformity of the crater at distances beyond 1000 ft, it seems fairly clear that the deep hole is a result of geologic structure. In fact, the 120-ft depth at Ground Zerois influ- enced to some extent because it lies on the flank of the sink hole. In the absence of this structural weakness, the Mike crater may have been no more than 110 ft instead of the present depth of 120 ft at Ground Zero. 3.2 SIZE AND SHAPE IN CRATER SCALING In this section the results in Figs. 3.1 to 3.4 are correlated to give a genera! description for