Telephoto videos capture fissure activity within Halema‘uma‘u crater on December 22, 2020, at approximately 3:35 PM HST. (1) The first video shows the main northern fissure. The lava fountains have built up a horseshoe-shaped spatter cone (dark in color) around the perimeter of the vent. (2) 2) The second video shows the smaller western fissure. This fissure feeds a small channel of lava that is entering the lava lake (not visible in video). Spatter continues to build up around the perimeter of the vent. When exposed to the air, the spatter quickly cools and turns a dark brown/black color. Molten spatter can be seen landing on the adjacent spatter cone and quickly changing color as it is quenched by the air.
Video at: https://www.usgs.gov/media/videos/fissure-activity-within-halema-uma-u-crater-k-lauea-volcano