  We have calculated the effects of giant convection cells also know as
sectoral rolls or banana cells, on p-mode splitting coefficients. We use the
technique of quasi-degenerate perturbation theory formulated by Lavely &
Ritzwoller in order to estimate the frequency shifts. A possible way of
detecting giant cells is to look for even splitting coefficients of 'nearly
degenerate' modes in the observational data since these modes have the largest
shifts. We find that banana cells having an azimuthal wave number of 16 and
maximum vertical velocity of 180 m/s cannot be ruled out from GONG data for
even splitting coefficients.
