No just kidding. It's lava. Hawai'i
Edit: Oh bah. It seems the original excellent drone footage was sold to media, and the poster removed it from youtube.
Gone now: youtube /watch?v=eNa3Vkj1KkI
Fragment of the drone footage included in the Guardian channel here: youtube /watch?v=IF8-l3l-2b8
A still from the footage, so lacking the delicious bubbling lava goodness:
In video, it really looked like a massive linear electric melting effect. Across a road.