Pele's hair. That's the parking lot downwind of the lava lake in Kilauea's summit caldera. The band of fuzzy stuff (Pele's hair) is about a meter wide. If you click on the photo you can see it in more detail.
Here is an infrared webcam view of the lava lake (it updates every 15 minutes of so):
Here it is in visible light (a bit obscured by gasses during daylight hours)
Here it is from two miles away at the Hawaii Volcano Observatory (the parking lot with the Pele's hair is behind the plume of gas):
FWIW - this is my playground. I live on the flank of Kilauea, hike and photograph the volcanoes here all of the time.
Note: If you click on the webcam pictures above you can see them zoomed in, with a horizontal scroll bar just below this text to pan with.