Pu‘u ‘Ō‘ō has changed dramatically over the years. This map shows the configuration of Pu‘u ‘Ō‘ō's current crater (outlined in yellow) and vents (marked in red). The base image is a mosaic created from photographs captured during a helicopter overflight on January 19, 2016. The current crater, with a maximum width of about 290 m (317 yd), is nested within a much larger crater that was present in early 2011. The current crater is about 20 m (66 ft) deep and has distinct embayments at its northeast, northwest, and south sides. These embayments were pits when the current crater formed in mid-2014. A short distance west of the current crater is a 50-m- (~165-ft-) wide pit, informallly called the West pit, that contains a 25-m- (~80-ft-) wide lava pond. The source of the currently active June 27th lava flow is a vent on the northeast flank of Pu‘u ‘Ō‘ō, about 250 m (273 yd) downslope from the crater rim.