150 +— 45 7 —— 100 $r23/65,90 4 W INVENTORY-Sr% MC/SQ MILE = = INVENTORY ORRATE o W SN — 50 4 —] 30 2 _ H— FE 10 — 10S Ww ~ 49 8_ g w . uw 5 8 9 4 47 3 6 3 Ww We ul H- <«tL os 45 44 — 3 se si | 1952 1953 1954 1955 ! 1956 i 4957 0 1958 — TEXAS TREE RINGS (WILLIAMS OF HUMBLE OIL & REFININ 6 BLE OIL | | CO.) Va © RING O RING RING ° MOSS VES RING “2.46 %/YR 1955 INCREASE IN C'* CONTENT, % 3.6%/YR TwiGs @ o an ° an nm o INCREASE IN C'* CONTENT, % tM an Fig. 9—Stratospheric inventory and rate of fallout; also Sr®/sr® ratio. $956 1957 ~~ SURFACE CO, AT MAKARA 1955 L 1956 Fig. 10—Bomb C#effect. 264 | 2.1%/YR 1957 a «£