NB: This has been moved to the top to provide a bit of perspective on yesterday’s Mb 8.9 earthquake in Japan.
What with earthquakes, volcanoes, and other sorts of mayhem going on, it seems a good time to provide a little perspective. Every natural disaster provides energy [1], as do our daily activities. But how much? Here is a chart comparing the energy of several common things and the amount of energy used by a typical home:
| Source | TNT Equivalent | Energy produced (J) | Household use |
| Running a marathon (26.2 miles) | 2.6 kg | 1.07E+07 | 1 house for 2.4 hours |
| Lightning bolt | 67 kg | 5.00E+09 | 1 house for 46 days |
| US Household annual use | 1/2 kT | 3.96E+10 | 1 house for 1 year |
| Magnitude 4 earthquake | 1 kT | 6.31E+10 | 1 house for 1.6 years |
| Little Boy | 18 kT | 7.50E+13 | 1,395 houses 1 year |
| Fat Man | 21 kT | 8.80E+13 | 2,222 houses 1 year |
| Magnitude 6 earthquake | 1e3 kT | 4.17E+15 | 66,086 houses 1 year |
| Mt St Helens eruption | 24 MT | 1.00E+18 | US for two weeks |
| US Energy production | 611 MT | 2.54E+19 | US for one year |
| Yellowstone eruption | 6 GT | 4.50E+21 | US for 177 years |
| Magnitude 9.0 earthquake Chile | 320 GT | 1.33E+23 | US for 5,236 years |
| Sun’s output for one minute | 30,900 GT | 2.32E+28 | US for 900,000,000 years |
John
[1] One of my advisors was fond of telling people who made atomic bombs [a] that they should not be so proud of the technological terror that they had created, as it paled beside the power of the force.
[a] Geophysicists are very popular in the atomic bomb testing business, as we can tell the physicists how much energy was released and locate explosions all over the world.
I liked note [1], that would have been a fun professor
that would have been a fun professor
He is. Then again, I've been pretty lucky in my major professors. One used to ride a jet-powered bicycle into class, wearing a shirt that said "Physics is F=μa; Chemistry stinks". Another would set us homework problems such as "You have 24 hours and a nuclear warhead. How big of a comet can you divert in order to destroy the Earth?" John
I think your TNT equivalent entry for a magnitude 4 quake is incorrect. You have 1 kT there, and the previous entry is 1/2 kT but the energy in joules is 105 times the previous entry.
Actually, I have two errors in that row. The correct value for a M4 earthquake should be 6×10^10 J, which means that the TNT value was correct and the household use was wrong. I’ve corrected the values on my blog – thank you for catching the error!
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