Tuesday, November 4, 2008

Thin Bed?

Hi Professor,

What would be a the thickness of thin beds roughly, in terms of travletime in ms or seconds, if you have an idea. Even a nudge in the right direction, in terms of references would be useful as well.

Thank you

------------------------REPLY--------------------------

Well...

The vertical resolution limit defines the thickness of a thin bed

h = L/4 = v / (4*f) = v*T/4 = v*t/2

L = wavelength, v = thin bed interval velocity, f = dominant
frequency, T = dominant period = 1 / f, and t = 2-way travel time
through the thin bed. Solving for the time thickness, t, gives

t = 2*h/v = L/2 = 1/(2*f) = T/2

So it looks like a bed is "thin" in a time sense when it is less than
or equal to the one-half of the period (for a monohromatic wave) or
one-half of the dominant period (for a broadband wave).

For example, if a wavelet has dominant frequency of about 30 Hz, a thin bed is one that has less than 15 ms time thickness.