Here is a rare view into the eruptive vent on the floor of Halemaumau crater. This shot was taken during a, "high lava stand", that is, the lava has risen to a higher point than what is considered normal, or baseline. In this photo, the lava surface is within about 330 feet of the floor of Halemaumau, and the crustal plates on the surface of the lava lake are clearly visible. Note also, that the emissions from the vent are wispy and thin. Emission levels drop during high lava stands, then increase as the lava recedes.