Waves in strata

Vertical exaggeration

The first task in interpretation of seismic data is to figure out the approximate numerical value of the vertical exaggeration. The vertical exaggeration is $2/v$ because it is the ratio of the apparent slope $\Delta \tau / \Delta x$ to the actual slope $\Delta z/ \Delta x$ where $\Delta \tau = 2 \Delta z / v$. Since the velocity generally increases with depth, the vertical exaggeration generally decreases with depth.

For velocity-stratified media, the time-to-depth conversion formula is

$$\tau (z) = \int_0^z {2 dz \over v (z) } ... ... or} \ { d \tau \over dz } = {2 \over v }$$ (2)

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