® .1105 r @ de due to the low sound velocity at high altitudes, where the pressure wave may lay behind its corresponding part at the surface, and tend to support the interice of the wave, near the end of the positive phase. The normal lapee rate of temperature with altitudes on MIKE, is not unlike the thermal effect, observed for high heights of burat) in a sense it results in similer precursor setion at the surface, which also tends to lengthen the positive phase. Effects Pertinent measuremeats were made by the projectslisted above, and in particular, by Sandia Corpcration in Projects 6.3, and by LASL in the photo- graphy for 6.2, in 6,3, and in Project 6.9 - “Bete Densitoneter". | rd The fast rise time obtained by Santia Corporation at Bngebdi is remarkable because it may be the sharpest rise time ever cbeerved st this pressure level on an stonie bend. Qne veeulis that the sharp rise tine at high pressures over ifeal surfaces is a theowetical prediction, despite Greenhouse-Ruster- Tumbler reealte. ‘This gauge was near the shore on Ingebi, vith « comsiéerable run of vater between it and the boab. Another gauge inground baffle, placed by Sandia near the GCE structure cm Engebdi, several thousand sect in- land, give caly 9jet and a poor wave fern, to be compared with 16pet obtained by interpolation between their sessurements at Ingebi and Mutit, or18 yet as predicted for 1deal surface asd hasogeeces ataceybere. Reflected pressures messured on the structure were shout 96 pei, a reastnehMlysimil redintion below AS pet expectel frou nowmal reflection of a 16 pat shock, or 52 pei as expected from normal reflestion of an18 pei sheck. ‘Prom, these régiite coe infers shore, 289 av . 20) AVAILABLE COPY SND ces that a surface effuct wee probably present nband on Ingabi, butnotnear the