Flash,
Not really a good example the main reason for the block pattern on m/c racing tyres is to allow more movement of the compound to increase the heat generated (more heat - better adhesion to the road/track surface). Transverse or diagonal grooves alone will disperse water away from the contact area.
I personally think that talk of youngs modulus and other deep scientific data is too much and it is simply a matter of when the standing water is deeper than the available tread depth (allowing for compound compression due to material characteristics and tyre pressure) which causes aquaplanning to start.
Only my lay opinion though!
Cheers.