# Seismic Energy Calculator

## Converts magnitude of seismic energy between Joule and TNT explosive equivalent. | ||

Magnitude earthquake has several types, and currently the moment magnitude is mainly used. This calculator uses the moment magnitude. The Magnitude increases +2, energy increases 1000 times. 1J = 1N*m 1TNT-ton=4.184GJ |

Seismic Energy

[1-6] /6 | Disp-Num |

- Purpose of use
- Wanted to know how the moment magnitude scale is defined.

[1] 2021/01/21 18:33 50 years old level / A retired person / Very /

- Purpose of use
- An M4.7 earthquake happened today just 150 km away (but 130 km deep), but I didn't feel it in my room, so was curious to see how many kilotons of TNT it equals (0.17 kt only, pretty tiny nuke :-D an only 1/10th of Beirut explosion).

[2] 2020/10/02 08:38 40 years old level / Self-employed people / Useful /

- Purpose of use
- An article referencing to 50 fold of Hiroshima atomic bomb for a 7.2 Mw earthquake.

I am fact checking through this website

[3] 2019/07/15 12:46 30 years old level / High-school/ University/ Grad student / Useful /

- Purpose of use
- Research for a seismic model.
- Comment/Request
- Thank you for updating the equations!

I experienced 2 of the quakes in your list above.

[4] 2017/09/20 05:18 60 years old level or over / An engineer / Very /

- Purpose of use
- Converting magnitude into energy for a seismic model.
- Comment/Request
- It would be helpful if you provided several versions of the equation. For example, one for solving for M, another for solving for J. The equation that is given has both terms but neither is isolated. Rearranging is relatively simple algebraic rules but I need to program it into a spreadsheet. Can you make it a little easier for us?
- from Keisan
- We have fixed it to be able to select "Magnitude" or "Energy".

From the above equations,

the followings are obtained.

J = 10^(4.8+1.5M)

M = (log(J) - 4.8)/1.5

[5] 2017/09/08 05:04 60 years old level or over / An engineer / Useful /

- Purpose of use
- Math project

[6] 2015/05/13 14:01 Under 20 years old / High-school/ University/ Grad student / Useful /

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