(BIVN) – The ongoing Kīlauea summit eruption was paused as of Monday morning, but scientists expect the next eruptive episode to begin at any moment. 

The USGS Volcano Alert Level for Kīlauea is WATCH. Over the weekend, scientists reported Episode 15 was likely to begin late Sunday or Monday in Hawaiʻi Volcanoes National Park. 

Over social media, the USGS Hawaiian Volcano Observatory wrote there was “a wee chance of (the start of the episode) being delayed to Monday night.”

USGS webcam view of the inactive vent at the summit of Kīlauea on Monday morning, March 24

From the USGS HVO update on Sunday:

Summit Observations:

Episode 14 lasted 28 hours and 23 minutes with the last 7 hours and 19 minutes consisting of fountains up to 600 feet (180 meters) high predominantly from the south vent. Lava flows and fountains stopped erupting from the south vent within Halemaʻumaʻu crater at 1:49 p.m. HST on March 20. Fountains from the north vent ceased 11 minutes earlier. Lava flows from episode 14 covered 75% of the Halemaʻumaʻu crater floor. Spots of orange glow can still be seen on the crater floor at night as the erupted lava continues to cool. The vents continue to degas and glow at night, indicating magma remains at shallow levels in the vent. A detailed account of the eruption can be found in the Kīlauea update and the Status Report from March 20.

Deflationary tilt at the summit recorded about 6 microradians lost during this episode using the the Uēkahuna (UWD) tiltmeter. The UWD tiltmeter has since experienced instrument malfunction and is not accurately recording tilt. The Sandhill (SDH) tiltmeter is now being used to track summit deformation. The SDH tiltmeter has recorded inflationary tilt that is about 75% of the tilt lost during episode 14. Seismic tremor decreased significantly at the end of episode 14 but remains above background.

Volcanic gas emissions remain elevated. A maximum sulfur dioxide (SO2) emission rate measured in the morning on March 20 reached approximately 50,000 t/d. Based on measurements made during earlier episodes and pauses, SO2 emission rates are likely to be approximately 1,000 t/d during the current pause. An SO2 emission rate of 1,500 t/d was measured on March 20 at 5:00 p.m. HST.

Strands of volcanic glass known as Pele’s Hair have been reported on surfaces throughout the summit area of Hawai’i Volcanoes National Park and surrounding communities.

USGS: “This reference map depicts the Kīlauea summit eruption within Halema‘uma‘u crater that began on December 23, 2024. As of this posting on March 18, the eruption has had thirteen episodes, with the most recent occurring on March 11. Most of the map data included here were collected during a Hawaiian Volcano Observatory helicopter overflight on the morning of March 14, so the provided statistics are reflective of the entire eruption to this point.”

Rates of seismicity and ground deformation remain very low in the East Rift Zone and Southwest Rift Zone with no significant earthquake activity in the past 24 hours. Sulfur dioxide (SO2) emissions from the East Rift Zone remain below detection limit.

Analysis: 

The current eruption is marked by episodic fountaining not seen in any of the other Halemaʻumaʻu eruptions since 2020. Fountains and lava flows have erupted from two vents that we refer to as the north vent and south vent. The 14 fountaining episodes lasted from a few hours to over a week. Each fountaining episode has been accompanied by strong deflation of the summit region. Pauses between the fountaining episodes have been marked by an immediate change from deflation to inflation as the magma chamber recharges and repressurizes.

Analysis of inflationary tilt patterns prior to the onset of each fountaining episode allows a time window of probability for the onset of new episodes to be estimated. These are calculated using both minimum inflation necessary to start a new eruption and the rate of inflation fit to data derived from past eruptive episodes. The presence of shallow magma in the vents and the rapid rebound of tilt at the end of episode 14 indicate that the eruption is likely to resume. Calculation of the likely time the start of the next episode has been recalibrated using SDH tiltmeter data. The most likely time window for the start of episode 15 is late Sunday, March 23 to Monday, March 24, with Sunday evening to Monday morning as the most likely. This estimate may be revised if inflation rates from SDH change significantly.