‘ 2.%¢ Darived Curves 2.2.1 Pesk Ovarpresawe vo Diao” Figura % shows the peak refire veo overgcelcure 4s 2B Prileugs. thee* waiu’ furntion of distame for tire yieids indie ed erasr ts be other ecurres which follew) thes? ocredistiene arc im ety have been takes from the ISM sokutier (a: ecnodavent with cong ag wement wth There is & predictions made on the basis of Greenhouse tewev enct. substantial differents; the tover expircic+s mse tr a Sea mal’. enough that the pressurea reccided watt esern’ lacy coer a sant surface, In this case, the exphosion 6 6. ever weisr. the presen. theory indicates that somewhat highayT pecs pressure shown be obie ved than if the expiorzien occured entirely cvev Land within ine fire’ few miles from the bomb, the peek prassuves may be reduced conyiderably from the value shown here by the therma? effec. oy. ihe grovrd peler to shock arrival. At lone distances, such ax at Parry and Briwstck. the pressures may bs lewe> ar higher for reasene cifed in Sec, 2 3 above, However, at leng distances, the pesk preseuTe ls a slowly varying function of yield, such that on sight-feld increase in yield merely deubles the pressure. 2.@.2 Peak Material Velocity vs Disvans Coincident with the arrival cf the shack wave ia a wave of material velocity whose peak value as a fur-tion cf diatancse is given in Fig. 2. The relationship be.vecr peak material velotity and reeprpeure is 5 Ue Ap et Po LEE 2 Cy Veet. 7) nhere u = material velocity C, = <> P/P ~ ambient sound velotity overpressure, in atwospheres The duration of this wind is comparable to the pesiti-:: duration of the blast pressure. 2of03 Presaure vs Tins Figures 3, hb, 5, and 6 give estimates fer the pressure ¥¢ time wave at selected pressure levels of 4,600, 105, 40 and % p3i and indicate the variation in the ferm of the pressure wave at these prassure levels, At high pressures and clese in there is nce negative phase; pressure ascays assymptotically te wre. Meresver, "length of the positive phase" is strongly influenced in this regien by the rise of the fireball, which at tenuates pressures shortly after shock arrival, and should reduce the