how did volcanoes form land masses?

Question

the hawaiian land masses

Answer 1

The simple answer is that they didn´t, the Hawaiian Islands do not fit that description, they are islands. Land masses are.....well....massive.

What volcanic action can do, and Hawaii is a great example this, is to force new solid matter to the surface of the sea and effectively create ´new´land. In fact most of the pacific islands are sunken lands, i.e. there was a lot more there before the major ( 100 mtr +/- ) rise average sea levels at the end of the great ice-age, approximately 13,000 years ago.