Example preset
Choose a preset to fill the form and refresh results instantly.
Inputs
Results
Calculation procedure
Assumptions & limits
- This is an educational approximation based on a rectangular fault model (A=L×W) and simplified with uniform slip and constant rigidity.
- Use this tool as a learning estimate and verify hazard-related decisions with official and professional sources.
- M0 has the same dimension as N m (J), but it is not the radiant energy itself.
- The offset of the Mw formula uses k=6.06 (there are slight differences depending on literature and customs).
FAQ
What is M0 (earthquake moment)?
It is an index of earthquake scale estimated from fault area, average slip, and rigidity.
What is Mw (moment magnitude)?
This is a logarithmically scaled magnitude of M0, and is an index that is difficult to saturate even in large earthquakes.
Is M0 earthquake energy?
Although the dimensions are the same, it is not the radiant energy itself.
What is dyne·cm?
This is the unit used to express seismic moment in the CGS unit system. 1 N·m = 10^7 dyne·cm.
What should I do first on this page?
Start with the minimum required inputs or the first action shown near the primary button. Keep optional settings at defaults for a baseline run, then change one setting at a time so you can explain what caused each output change.
How to use Moment magnitude Mw calculation (fault → M0 → Mw) effectively
What this calculator does
This page is for estimating outcomes by changing inputs in one controlled workflow. The model keeps your focus on variables, not output shape. Start with stable assumptions, then test sensitivity by changing one key input at a time to observe directional impact.
Input meaning and unit policy
Each input has an expected unit and a typical range. For reliable interpretation, check whether you are using the same unit system, period, and base assumptions across all runs. Unit mismatch is the most common source of unexpected drift in numeric results.
Use-case sequence
A practical sequence is: first run with defaults, then create a baseline log, then run one alternative scenario, and finally compare only the changed output metric. This sequence reduces cognitive load and prevents false pattern recognition in early experiments.
Common mistakes to avoid
Avoid changing too many variables at once, mixing incompatible data sources, and interpreting a one-time output without checking robustness. A single contradictory input can flip conclusions, so keep each experiment minimal and document assumptions as part of your note.
Interpretation guidance
Review both magnitude and direction. Direction tells you whether a strategy moves outcomes in the desired direction, while magnitude helps you judge practicality. If both agree, you can proceed; if not, rebuild the baseline and verify constraints before deciding.
Operational checkpoint 1
Record the exact values and intent before you finalize any comparison. Confirm the unit system, date context, and business constraints. Compare outputs side by side and check whether differences are explained by one changed variable or by hidden assumptions. This checkpoint often reveals the single factor that changed everything.
Related tools
- Geology/Environment (Disaster prevention (earthquake/tsunami/ground))
- Earthquake magnitude and energy comparison calculator
- P wave/S wave: Initial tremor duration → epicenter distance/occurrence time (for education) (ES-007)
- Earthquake catalog → Gutenberg–Richter (b-value estimation) (ES-024)
- Ground: Simple indicator of liquefaction (for educational use) (ES-025)
Comments
Comments are only loaded on request (Giscus).