You've got an interesting concept started. If you're trying to model an explosive eruption, like Vesuvius or Mt. Ste. Helens, there's a lot more ash, clouds and grey. IF you're looking at Hawaiian Island style eruptions, the lava fountains out at the vent source, and then acts like a river. The volcano is very low and not very jagged (at least for some types of lava) I think the frequency and noise of some textures do need to be increased, and light should come more from the lava than shining on the lava. You'd never be able to see the moon in the picture because of the intense light and your view being so close to the lava. These are just suggestions to consider to make it more realistic. I hope they inspire something to help you out. I look forward to the outcome of this work.