Terrawatch: what does the inside of a volcano look like?

Detailed analysis of a buried extinct volcano in the Faroe-Shetland Basin reveals some surprises

If you were to slice a volcano in half, what would it look like inside? For most volcanoes it's assumed that there is a large magma chamber which is connected to the surface by a narrow conduit: a structure referred to as the balloon and straw" model. But detailed analysis of a buried extinct volcano in the Faroe-Shetland Basin reveals that volcano plumbing isn't as straightforward as first thought.

Erlend last erupted 55m years ago and today lies buried under more than a kilometre of sediment. Using 3D seismic images and data from oil exploration wells, Faye Walker, from the University of Aberdeen, and colleagues have pieced together the plumbing system inside the fossilised volcano. Their images, published in the journal Geology, reveal a Christmas tree" structure inside, suggesting that the magma chamber grew like a tree, with each fresh batch of magma adding a new set of gently downward sloping branches.