Refraction Travel-Time Curve Builder

Layer 1 velocity $V_1$ 800 m/s

Layer 2 velocity $V_2$ 2500 m/s

Layer 1 thickness $h$ 8 m

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Crossover distance x꜀ (m)

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Intercept time tᵢ (ms)

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Depth from intercept (m)

Direct wave $t=x/V_1$; head wave $t=\dfrac{x}{V_2}+t_i$ with intercept $t_i=\dfrac{2h\sqrt{V_2^2-V_1^2}}{V_1 V_2}$. Depth from intercept: $h=\dfrac{t_i}{2}\dfrac{V_1 V_2}{\sqrt{V_2^2-V_1^2}}$; crossover $x_c=2h\sqrt{\dfrac{V_2+V_1}{V_2-V_1}}$.