The summit area of Kīlauea Volcano has undergone significant changes since April 2018. On April 21, the lava lake within Halema‘uma‘u overflowed onto the crater floor as the volcano's magmatic system pressurized. In the East Rift Zone, less lava was erupting from the Pu‘u ‘Ō‘ō vent, with small flows at the cone and in the crater. On April 30, the floor of the Pu‘u ‘Ō‘ō crater collapsed, as subsurface pressure forced open a pathway for magma to travel from Pu‘u ‘Ō‘ō into the lower East Rift Zone. The pathway follows a well-established magma transport system within Kīlauea that last saw a magma intrusion in 1960. As magma moved into the lower East Rift Zone, pressure decreased in the summit's magmatic system and the lava lake level began to drop. The summit also started to deflate due to the pressure decrease, as magma stored beneath the summit was clearly draining into the East Rift Zone.
As summit subsidence persisted, the number of earthquakes increased. Prior to the onset of deflation, about 10 earthquakes per day were typical at the summit. As of late June 2018, there are about 600 earthquakes located in the same region on a daily basis. Many of these earthquakes are strong enough to be felt, and some can be damaging. These earthquakes are understandably causing concern, especially in Volcano Village and surrounding subdivisions. These FAQs will help answer some of the most commonly asked questions about the nature of Kīlauea's summit activity, and especially the numerous earthquakes that are occurring in the area.