(BIVN) – Kīlauea is not erupting, and after a brief increase in the USGS Alert Level to WATCH, the status of the Hawaiʻi island volcano has been returned to ADVISORY.

The Aviation Color Code has also been lowered from ORANGE to YELLOW.

Localized earthquake and ground deformation rates in Kīlauea’s upper East Rift Zone decreased significantly following the “burst of intense activity” that occurred early Tuesday morning. 

Seismicity remains elevated, scientists warn, explaining that the “pulsing nature of this activity may represent stages in intrusive activity beneath the upper East Rift Zone region.” 

“Additional seismic pulses or swarms may occur with little or no warning and result in either continued intrusion of magma or eruption of lava,” the USGS Hawaiian Volcano Observatory stated.

The Observatory says field crews examined Chain of Craters Road in Hawaiʻi Volcanoes National Park this morning and did not observe any major cracks associated with the recent activity.

From the USGS HVO activity notice posted at 9:04 a.m. HST:

Earthquake activity this morning was centered near Pauahi Crater in the upper East Rift Zone, along Chain of Craters Road in Hawai‘i Volcanoes National Park. More than 100 events occurred between 3:00–9:00 a.m. HST this morning, at depths of 1–3 km (0.6–1.8 miles) beneath the surface. Most events were smaller than magnitude-3, though there were 8 events larger. The largest event was a magnitude-3.4. Earthquake activity was accompanied by an abrupt change in ground deformation patterns in the upper East Rift Zone, shown by the ESC tiltmeter. Tiltmeters in Kīlauea summit region (instruments SDH, southwest of the summit, and UWE, northwest of the summit) did not show significant changes associated with this activity.

USGS: “This reference map depicts the features on Kīlauea’s upper East Rift Zone. Chain of Craters Road in Hawaiʻi Volcanoes National Park follows the path of the upper East Rift Zone. Pit craters, thermal areas, and lava flows are evidence of a long history of magma moving along this rift zone pathway. Upper East Rift Zone eruptions have typically occurred near the southeast margin of Kaluapele, or where the upper East Rift Zone meets the middle East Rift Zone near Pauahi Crater.”

The onset of this morning’s upper East Rift Zone swarm was similar in intensity to that seen preceding Kīlauea summit eruptions of the past few years. This coupled with the sharp displacement on the ESC tiltmeter and strong clustering of these earthquakes in the area beneath Pauahi Crater suggests that an intrusion of magma began at 3:30 this morning. The region around Pauahi Crater has a long history of intrusive and eruptive activity. The pulsing nature of this activity may represent stages in intrusive activity beneath this region in the past 24 hours. Additional seismic pulses or swarms may occur with little or no warning and result in either continued intrusion of magma or eruption of lava.