Hi Jeff, the island is volcanic. Most has been eroded, and in another 100,000 years there will be nothing left of Lord Howe. Glad you enjoyed Avatar. I loved the techno side, but I found it difficult to enjoy the baby-boomer nostalgia (mother nature connecting all creatures, the noble-savage myth etc etc).
That is an awesome looking picture Julian. Just a hunch, but I'm guessing this is a volcanic island. That lava monster looks a little like one of the critters on Pandora. (Yeah, I just saw Avatar.)