The top picture is of an area where a lava dam formed.  Behind the dam, the lava piled up and started to form irregular ridges.  Eventually the pressure of the lava was too much and the dam broke.  The lava would spread out into these glowing orange areas.  It was a striking sight to see the light of the lava in the otherwise blackness of the night. 

The second picture is of a free flowing area of the lava stream, more akin to a river than anything else.  I have to tell you, seeing lava was really one of the highlights of the trip.  It's not something that I anticipated seeing when I came to Hawaii but I'm really happy that I did see it.  I've always watched science shows and thought it impressive, yet there is nothing like seeing it in person.  I appreciate the science shows more now that I've seen this.