What happens when Lava meets ocean?
Hawaii and other island volcanoesare in a steady competition for the freshest, most up-to-date rock round. Whilst the lava meets the ocean, it cools speedy while boiling the ocean into steam. This consequences in a specific texture: the quenching produces a glassy outer surface from the lava cooling too quickly for crystal shape to develop. This insulates the inner of the globs, trapping any dissolved gasoline as bubbles and permitting internal microcrystal growth from the slightly slower cooling charge.