That ring structure is a bit of a puzzler. But, going out on a complete flight of fancy, how bad can it get, possibly..? There are two flavours of really, really bad to choose from:

1. The ring is the start of a ring fault bounding a caldera collapse. This could potentially get to VEI6, depending on the magma sources and mixing with the overlying 700 m of water ice. In that case, yes, it would certainly mess up transatlantic flights, especially with where the wind's blowing.

2. It's the start of a major fissure eruption, which we've been kind-of anticipating is going to turn up in the next few decades anyway. This volcano has produced the largest Holocene eruptions known, by volume. In that case, they won't be too much ash, but poisonous clouds instead, belching out for months on end, and drifting down over parts of Europe. Last time, 10000 people died in Scotland alone, if memory serves - and Laki wasn't that big, as these things go.

But it might just fizzle out and do nothing.

This time.

Sweet dreams...