This Quicktime movie shows a time-lapse sequence of activity at the northeast spatter cone
in Pu‘u ‘Ō‘ō crater on February 9-10. Rapid fluctuations in the height of the lava
pond are caused by gas pistoning, which is the gradual buildup and release of gas in the pond. Mauna Kea is visible in the upper right portion of the frame. The sequence was captured by an inexpensive time-lapse camera, whose plastic housing was warped by the extreme heat.