The Oceans expand yes, other matter would expand too but much less so and would probably not be expanding at all as the warming trend is very slight on land. Water is very sensitive to thermal whereas rock is not. But we can only measure it through the use of satellites as the expansion is very minute...relatively speaking of course

You should really check out a Science documentary series called Cosmos by Carl Sagan, it's a bit old but most of the info within that great series is still good today. The reason why I say this is because the First Episode deals with the Obolisks and the Circumphrance of the Earth and how he figured it out

[edit on 19-6-2005 by sardion2000]