Shear waves move material sideways as they travel and cannot pass through liquids – which is how seismologists discovered that Earth’s outer core is liquid. Engineers measure them to assess soil stiffness for earthquake design.
How to use the Shear Wave Velocity Calculator
- Material
- Shear modulus G
- Density ρ
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Choose a material or enter its shear modulus and density.
Inputs explained
| Field | What to enter |
|---|---|
| Material | Choose one: Structural steel, Aluminium, Copper, Glass … |
| Shear modulus G | Units: GPa, MPa, Pa, psi, Mpsi |
| Density ρ | Units: kg/m³, g/cm³, g/mL, lb/ft³, lb/in³ |
Example values
How the main result changes when Shear modulus G changes and everything else stays at the example values above:
| Shear modulus G (GPa) | Shear wave velocity v_s (m/s) |
|---|---|
| 39.65 | 3,178.3503 |
| 59.47 | 3,178.3503 |
| 79.3 | 3,178.3503 |
| 99.13 | 3,178.3503 |
| 118.95 | 3,178.3503 |
| 158.6 | 3,178.3503 |
Formula
v_s = √(G / ρ)
Worked example
Inputs — Material: Structural steel.
Results — Shear wave velocity v_s = 3,178.35033 m/s; Seismic site class (top 30 m, for soils/rock) = A – hard rock.
Key terms
- S-wave
- A transverse (shear) elastic wave.
Frequently asked questions
Why can't S-waves travel through liquids?
Liquids have no shear stiffness (G = 0).
How fast are S-waves in rock?
Typically 2–4 km/s.
What is V_s30?
The average shear-wave velocity in the top 30 m, used to classify building sites.
How do S and P waves compare?
S-waves are slower, roughly 0.6 times the P-wave speed.