(BIVN) – Kīlauea volcano on Hawaiʻi island is not erupting, and the seismicity at the summit has decreased since an earthquake swarm that was observed Friday evening.

Scientists say there has been increased seismicity over the past three weeks, indicating heightened activity. The USGS volcano alert level remains at ADVISORY.

From the USGS Hawaiian Volcano Observatory on Sunday:

Summit Observations:  Earthquake activity has been increasing over the past three weeks beneath the summit of Kīlauea. Activity has alternated between typical shallow, 0.5-2.5 miles (1-4 km) earthquakes beneath the south caldera region and 3-6 miles (5-10 km) deep earthquakes directly beneath Kīlauea caldera. While daily rates of seismicity have decreased following the deep earthquake swarm observed Friday evening, they remain elevated. Occasional short-lived bursts (10-30 minutes) of low frequency earthquakes continue to indicate movement of magma in the subsurface.

Kīlaueaʻs summit remains inflated, but recent ground deformation remains low with tiltmeters near Sand Hill and Uēkahuna showing no significant changes in the past day. Sulfur dioxide (SO2) gas emission rates have remained low since October 2023. An SO2 emission rate of approximately 96 tonnes per day was recorded on April 8.

USGS image from webcam on the northwest rim of the caldera showing the Kīlauea caldera and Halemaʻmaʻu on Monday morning.

Rift Zone Observations: Seismicity in Kīlauea’s upper East Rift Zone and Southwest Rift Zone remain low. No unusual activity has been noted along the middle and lower sections of Kīlauea’s East Rift Zone. We continue to closely monitor both rift zones.

Measurements from continuous gas monitoring stations downwind of Puʻuʻōʻō in the middle East Rift Zone—the site of 1983–2018 eruptive activity—continue to be below detection limits for SO2, indicating that SO2 emissions Puʻuʻōʻō are negligible.

Analysis: Last night’s earthquake swarm had a strong low frequency component indicating movement of magma within the summit system. This activity appears to have been deeper than normal activity that has preceded recent summit eruptions and HVO will continue to monitor the summit region closely. At this time, it is not possible to say with certainty if this renewed activity will lead to an eruption in the near future –or simply remain confined below ground. However, an eruption in Kīlauea’s summit region, within Hawai‘i Volcanoes National Park and away from infrastructure, is one potential outcome.

The USGS HVO says it will continue providing daily updates while Kīlauea is at a heightened state of unrest.