Left: Photo of the eastern delta showing the cracks parallel to the sea cliff. The delta is about 350-400 m (1150-1300 ft) wide and it extends about 150 m (490 ft) out from the old sea cliff. Deltas are unstable, and prone to collapse, because they are built on unconsolidated lava fragments. Right: Thermal image of the eastern delta showing heat in the cracks, as well as plumes of hot water (up to 70 degrees Celsius, or 160 degrees Fahrenheit in this image) extending out from the entry points. Photos taken Friday, September 30, 2016 courtesy of USGS/HVO