Scientists with the U.S. Geological Survey’s Hawaiian Volcano Observatory said Friday morning that earthquake activity and ground deformation has resumed beneath the southern part of Kilauea summit caldera within Hawaii Volcanoes National Park.
The observatory said the rate of ground deformation began increasing again around 6 p.m. Thursday and was followed by increased earthquake activity after 8:30 p.m. The renewed activity occurred in approximately the same location as the recent earthquake swarm between Monday and Wednesday within and south of the caldera.
“The combination of these observations indicate a second pulse of intrusive activity,” the observatory said Friday.
Most earthquakes in the renewed swarm were located between 0.6 and 1.8 miles beneath the surface, similar to the initial swarm. Approximately 200 earthquakes were recorded between 8:30 p.m. Thursday and Friday morning, less than half of the number of earthquakes detected in the initial swarm. The largest recorded earthquake was magnitude-2.8, with the majority of earthquakes less than magnitude 1.0.
During that time period, small earthquakes occurred at 16 detected earthquakes per hour, with a peak rate of 24 detected earthquakes per hour. Since 5 a.m. Friday, the average seismicity rate has dropped to about six detected earthquakes per hour, the observatory said.
“As of this statement, both earthquake and ground deformation rates in Kilauea’s summit region appear to be decreasing. In addition, there has been no indication of upward migration of earthquakes toward the surface or change in deformation that would indicate shallowing of the source intrusive activity,” the observatory said.
Kilauea’s Volcano Alert Level and Aviation Color Code remained at ADVISORY/YELLOW as of Friday afternoon.