em Steen bale oomstata , errr (1) If wind shear is <10° for the levels in question, ainer axis is 1/8 to 1/4 of the major axis (wnich is the entire vector for levels looked at). (This is case of 0-5,000 feet winds and 5-20,000 feet winds.) se a (2) If wind shear is >10° but <120°, minor aris is ¥ of asjer This is case for 20,000 feet winds to tropopause, and sonembat less ae, axis. for 65,000 to y5,000 feet winds. (3) If shear at levels making up vector under study is >120° draw circle with diameter = to entire resultant vector. The relatively light fall-out at Utirik (252 of the hot ares), hizher levels of intensity at Bikar (East and downwind of the hot area, i.e..6 r/hr at 3 plus 33 hours almost in downwind line with the superimposed ellipses or hot areas but definitely beyond the hot shadow), confirm the belief in che asscsed area of hot fall-out pattern above. me ee the picture for heaviest fall-out patterns north of this area is estab: ished. eer From initial land survey reports on Acngelap Atoll with levels at “4 2e Erippu Island (NB part of Atoll) still at 2.8 to 3.5 r/hr on B plus 7 days, . 1. From overall fall-out picture, it is concluded that fall-out aay nave reached Rongelap Island and Ailinginae later than the pessimistic tise of H plus 5 and # plus 4 hours, respectively. agrees Air vebmomsdien ate Arete CONCLUSIONS ; ortho (SSE of the area and fro= Gro=d Zero) received practically nothing because resultant vector wind speed froa the stem and, perbaps some of the mushroom fringe, was so low in velocity Nevada Proving Grounds over last 3 years, and (3) experience and data f>oa IVY-HIKE (limited cross-wind and upwind) end CzSTIS-ErayC itself. 4e Rongerik radiation intensity levels are ‘mown at caset and evecuatica time; calevlated roentgen dosage agrees with actual observations froz fits badges at this site . [s) acd Inelcsure 6 ae ee ae Boe se Bode n> ae bait cam od 5. The heaviest fall-cut pattern wes expected to pass north of eest cortheast from Ground Zero. ne is based ons (1) logical use of wind patterns existing during shot tine to _ fall-out, (2) multiple shot (tower or ground) fall-out pattera data froa aE because it does not tell exactly rhen the fall-out errives. Eowever, ‘* ‘ apparent that the 200-300 plus roentgens lifetizne dosage line sessed os or close to Ailinginae, Rongelap Island and Rongerik which are at €0-i00 alles in cases of Ailinginse and Rongelap and 130 miles to Rengerik from sround Zeroe The 1,000 plus roentgens lifetime dosage lines are exceeded as cne goes north from Rongelap Island to northern islands of that atoll. This analysis Re This type of analysis gives a feeling only for pattern of fall-out eekan) 3- ; through the SB to South from Ground Zero. Zniwetok received at about E pics 11 hours a build up to about 10 mr/hr for a period of about cive hours.