Table 2 Umbrella cloud radii and VEI indexes of several^a observed and ^bpast eruptions.

Calbuco, Chile, 2015^a

4

0.58 bulk volume⁶³

0.38 bulk volume⁶⁴

~50–60⁶³

Kelut, Indonesia, 2014^a

4

0.1 bulk volume⁶⁵

~40 (upwind)⁶⁶

Grímsvötn, Iceland, 2011^a

4

0.6–0.8 bulk volume

0.2–0.3 DRE⁶⁷

~25–50⁶⁷

Cordón Caulle, Chile, 2011^a

4–5

1.1 ± 0.2 tephra fallout volume²⁷

~35–60 (crosswind)²⁷

Sarychev Peak, Kurile, Russia, 2009^a

4

0.4 bulk volume⁶⁸

~25⁶⁹

Okmok, Alaska, U.S., 2008^a

4

0.26 DRE⁷⁰

~32.5⁷¹

Manam, Papua New Guinea, 2005^a

4

–

~90⁷²

Reventador, Ecuador, 2002^a

4

0.3 bulk volume⁷³

~42.5⁷¹

Pinatubo, Philippines, 1991^a

6

8.4–10.4 bulk volume⁷⁴

3.7–5.3 DRE⁷⁴

~250 (upwind)⁷⁵

Redoubt, Alaska, U.S., 1990^a

3

–

~17 (co-ignimbrite cloud)⁵⁷

Mount St. Helens, U.S., 1980^a

5

1.3 tephra fallout volume⁷⁶

0.73 tephra fallout volume⁷⁷

~15 (upwind)⁷⁸

Tambora, Indonesia, 1815^b

7

~100 tephra fallout volume⁷⁹

~500⁷⁹

Campanian eruption, Italy, ~40 ka B.P.^b

7

 ~210 tephra fallout volume⁵⁶

~430⁵⁶