## The awsome energy of nature: Japan earthquake

Citing USGS calculations the recent earthquake in Japan released as much energy as 600 Million Hiroshima Bombs – 80 Years of Global Energy Usage In Just Minutes.

The earthquake opened up a 400 km long gash in the ocean floor, releasing a surface energy of 1.9×10E17 joules (according to the USGS). The total energy released underground was about 205,000 times that on the surface. … That’s arguably more energy than what all of mankind has ever used so far.

A typical house will use 30 KwH per month or 3600 per year. That’s 12,960,000,000 joules. Comparing orders of magnitude we have 17 + 5 for the earthquake and ten for annual household use. That says 12 orders of magnitude is the multiple so the earthquake energy would power a typical household for a trillion years.

According to wikipedia, the US used 105 exajoules in 2005. exa is 10E18. So annual US use has a magnitude of 20. That means the earthquake released as much energy to last the entire US for a hundred years. The per-capita energy consumption has been fairly consistent for the last forty years at about 336 million BTU per year. That’s 3.5x10E11 joules for each of 300 million people which totals up to a magnitude 20 which fits with the total US number.

The difference between the 13x10E9 household electrical and the 3.5x10E11 per capita energy use is probably the difference between electrical and all energy sources. That ratio is 13:350 meaning electricity is about 1/30 of a person’s budget in a modern society.

Back to the headline: it appears that we trim 20 years off US use to include the rest of the world. i.e. the US is the major energy consumer on the planet. This makes some angry but that is because they don’t realize that the energy pool is not a fixed and limited resource and think the US is stealing something they should have. This earthquake energy analysis provides some context for what me might find if we knew where to look and how to use the energy in nature.

Playing with numbers can yield interesting insight but the point here is that you really have to expand your imagination when talking about nature. This was just one earthquake, albeit a big one, yet one simple measure for it makes man’s efforts by that measure look minuscule.