Lava flow advancing

Details of flow advance shown in 25-second clip. Lava oozes outward from base of flow, picks up loose flakes of crust (1-3 cm across) on ground surface, and lifts them up as flow thickens. This is how material once on ground surface gets onto top of flow. This is a common mode of advance of lava on nearly flat slope. Note: This is a large file because of its instructional value. Be patient, even those with broadband connections. And, turn down your sound; lots of wind noise.