I don't know the correct term for them, but this all most looks like lava sparks, and watch the left side you will see what looks like an oil plume shoot up once in a while also.Earlier the rov was halfway between where it is now and the light, that is where it started shooting huge chunks( basketball sized) up.Then it backed up to where it is now.Also not the red light on the right arm of the rov?That light came on right before it backed up.