Over the past 4 days, an intrusion of magma has triggered over 1500 earthquakes around Kīlauea’s Upper East Rift and caused significant uplift in the area between Pauahi Crater and the Maunaulu lava shield within Hawaiʻi Volcanoes National Park. Kīlauea’s summit, in contrast, has been deflating in response as built-up magma flows away to feed the intrusion, which has progressed through 4 distinct pulses with continuing activity in between. While the initial earthquakes concentrated near Maunaulu at the bend in the East Rift, the most recent pulse today has shifted back uprift to Koʻokoʻolau Crater and includes a magnitude 3.9 around 4:30 this morning, the largest event in the sequence thus far. In total, 24 earthquakes have registered between magnitudes 3 and 4 since Monday, with 9 of those events reported felt on-island.
According to the USGS Hawaiian Volcano Observatory, “there have been about 50 intrusive episodes like this in the Upper East Rift. In each case, magma moved underground in the Upper East Rift, causing earthquakes and ground deformation. Only five of the events resulted in Upper East Rift eruptions.” Thus, the most likely outcome is that the intrusion remains underground, but there is a chance it could result in a brief Upper East Rift eruption. However, the intrusion could also progress farther east into the Middle East Rift, which would lead to another set of possibilities. In any case, there is no short-term effect on the Lower East Rift, and no increased threat to people in our communities as a result of this activity. However, the National Park has instituted road, trail and campground closures to prohibit public access to the affected area. Thus, the primary threat to people remains from volcanic gas, which is presently being emitted around volcanic background rates of around 65 tonnes of SO2 per day from the summit on July 23, a source of concern for sensitive individuals nearby.
Maunaloa volcano remains quiet, continuing to recharge in the normal pattern following its 2022 eruption, with no visible influence from neighboring Kīlauea.
