In the above video you'll see the massive size of the eruption of the rift and the resulting lava flow forming a river of magma. I've never seen anything like this before.
In this video you'll see how low the viscosity of the lava coming from this eruption. It is clearly molten and moving below the surface but the "crust" of the flow cools enough to harden. It is as if to make it seem as a slow, relentless wall of rock is coming toward you.