Disastrous perspective

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


[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.

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4 thoughts on “Disastrous perspective

  1. 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

  2. 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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