1) Yes, I goofed by a factor of 10 in introducing the unit of a Sagan Threshold, as many readers noticed. The rest of the conversions and comparisons are correct, in particular, the energy of 100 one-megaton bombs, which he claims would bring on weeks of darkness and subzero temperatures (the "Sagan Threshold"), does equal 3.3 seconds of global sunshine or 4.2 x 10^17 joules or 4.2 x 10^24 ergs, but the energy of volcanic eruptions expressed in Sagan Thresholds are given below, with some new ones added (the energies are in ST's, or Sagan Thresholds):
| Place | Date | Energy | Volume | ||||
| Santorini | (Aegean | Sea) | 1500 B.C. | 240 | ST |
720 |
kM^3 |
| Laki | (Iceland) | 1783.0 | 206 | ST |
small |
||
| Tambora | (Sumbawa) | 1815.0 | 202 | ST |
150 |
kM^3 | |
| Coseguina | (Nicaragua) | 1835.0 | 115 | ST |
50 |
kM^3 | |
| Katmai | Alaska | 1912.0 | 48 | ST |
small |
||
| Bezimyanny | Kamchatka | 1955-56 | 5.3 | ST |
small |
||
| Mt.St.Helen | Wash. | 1980.0 | 2.4 | ST |
n/a |
||
The data are taken from F. M. Builard, Volcanos of the Earth (U.of Texas Press, 1976). The book shows that the problem is not new, for the work, which studies volcanoes, not nuclear winters, tells us (p.517) "Valuable information on how long the dust remains in the atmosphere (residence time) was provided by the study of residence time in the stratosphere of radioactive waste debris following nuclear bomb tests. Since the bomb debris and dust from the more violent volcanic eruptions probably reached comparable heights and were comparable in size, the comparison is valid... In a survey of major volcanic eruptions since 1855, Mitchell (1961) concluded that ... planetary temperatures are depressed by 0.5 degrees F or more in the first or second year after a major eruption..."
Who is Mitchell? Somebody who has not been paraded day-in day-out on TV screens between Preparation-H commercials.
2) Three more technical points refuting the E&S scary-tale are reported by Dr Jane Orient in the Mail Room of Fort Freedom (our computer data base, free for AtE subscribers.)
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Vol. 11, No. 6
Newsletter: Access to Energy Newsletter Archive Volume: Issues Issue/No.: Vol. 11, No. 6 Date: November 29, 2004 11:34 AM Title: Refereed by CBS
Copyright © 2004 - Access to Energy Newsletter Archive
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