These calculations are based on the conclusion presented in the paper by Levitus, S., J.I. Antonov, T.P. Boyer, and C. Stephens, "Warming of the World Ocean." Science, Vol. 287, pages 2225-2229 (2000). The abstract is shown here:
We quantify the interannual-to-decadal variability of the heat content (mean temperature) of the world ocean from the surface through 3000-meter depth for the period 1948 to 1998. The heat content of the world ocean increased by ~2 x [10.sup.23] joules between the mid-1950s and mid-1990s, representing a volume mean warming of 0.06 [degrees] C. This corresponds to a warming rate of 0.3 watt per meter squared (per unit area of Earth's surface). Substantial changes in heat content occurred in the 300- to 1000-meter layers of each ocean and in depths greater than 1000 meters of the North Atlantic. The global volume mean temperature increase for the 0- to 300-meter layer was 0.31 [degrees] C, corresponding to an increase in heat content for this layer of ~ 1023 joules between the mid-1950s and mid-1990s. The Atlantic and Pacific Oceans have undergone a net warming since the 1950s and the Indian Ocean has warmed since the mid-1960s, although the warming is not monotonic.
The US Geologic Survey estimated that the energy released in the May 18, 1980 eruption of Mount St. Helens to be 24 megatons thermal energy (7 by blast, rest through release of heat). The consequences of the blast were these (Reference):
| Elevation of summit | 9,677 feet before; 8,363 feet after; 1,314 feet removed |
| Volume removed | 0.67 cubic miles (3.7 billion cubic yards) |
1 Mt St Helen eruption = 1 mshe = 24 MT = 24 MT * 4.2 x 10^22 ergs/MT / (10^7 ergs/joule) = 100.8 * 10^15 joules
Ocean Energy Warming 1955-1995 = 2 x 10^23 joules = .198 * 10^7 mshe = 198 * 10^5 mshe
Per year, requires 495,000 Mt St Helen eruptions.