September 2024 Middle East Rift Zone Eruption

No molten lava or night-time glow is visible

The eruption ended as of September 20, 2024. Hawaiian Volcano Observatory lowered the volcano status from WATCH/ORANGE to ADVISORY/YELLOW on September 23. 

 

Duration:

1 minute, 38 seconds

On the night of September 15, a small eruption began in middle East Rift Zone on Kīlauea volcano, covering 4 acres with lava; after a brief pause, the eruption resumed at Nāpau crater and continued over the next few days, covering 156 acres in total and signaling a significant shift in volcanic activity at Kīlauea.

 

USGS thermal map of the initial vents that began erupting near the Nāpau crater on the night of September 15.

USGS map courtesy of Hawaiian Volcano Observatory.

On September 15, 2024 at 9pm Kīlauea began a new eruption along the middle East Rift Zone, about eight miles from Kaluapele, the summit caldera. This was the first East Rift Zone eruption since 2018. The new eruption came after nearly three months of heightened unrest and hundreds of earthquakes along the East Rift Zone, indicating that magma was on the move just below the surface.

Is it a real eruption if no one can see it? While the eruption area was within view of a Hawaiian Volcano Observatory (HVO) web cam, unusually heavy rain obscured the new lava from camera. As a consequence, HVO geologists were unsure if an eruption had actually occurred for several hours, though there were monitoring signal indicative of gas or steam venting. Meanwhile, in the nearby village of Volcano, residents noted unusually heavy sulfur dioxide or vog in the windless night air. They knew something must be happening.

The next morning HVO geologists flew over Kīlauea volcano's remote middle East Rift Zone and discovered new lava flows had indeed erupted over about an hour during the previous evening on September 15, 2024. Small lava pads erupted from two fissure segments in a couple hundred meters (hundred yards). Although the eruption paused by the time of the overflight, volcanic gas was still being emitted by the new fissure vents in this remote area of the park.

Numerous eruptions took place in Kīlauea's middle East Rift Zone during the 1960s–1970s. Most of these eruptions occurred between Hiʻiaka crater and Puʻuʻōʻō and lasted from less than one day to about two weeks, although there were long-lived eruptions at Maunaulu (1969–1971 and 1972–1974) and Puʻuʻōʻō (1983–2018).

 

USGS Hawaiian Volcano Observatory geologists collected a sample of lava from the middle East Rift Zone Kīlauea eruption in Nāpau crater, within a closed area Hawaiʻi Volcanoes National Park.

USGS image by A. Ellis

Is it over already? After only one hour of erupting on September 15, seen by no one, it appeared as if the eruption was done. No additional activity occured on September 16 until 6 p,m. when eruptive activity resumed. Activity continued overnight, but decreased overtime until the early morning hours of September 17, when new fissures opened further to the east in Nāpau crater. Fissures from the previous day's eruption continued to emit steam and gases while new fissures continue to erupt fresh lava in Nāpau crater.

Later that morning, geologists visited the site to gather samples. This process involves puting molten lava into a metal bucket and rapidly quenching it with water. The fast quench is needed to preserve the geochemistry of the fresh sample and prevent changes that would result from the formation of crystals during slow cooling. The samples will be taken to the lab for analysis, providing scientists with information about conditions in the magma chamber and magma's path to the surface.

While this eruption has been relatively small in terms of volume of lava, gas emmissions have registerd at very high levels at a nearby monitor station at Kealakomo Overlook.

 

USGS Hawaiian Volcano Observatory geologists conducted a reconnaissance overflight of the eruption near Nāpau crater on the middle East Rift Zone of Kīlauea. They observed lava cascading over the rim of the crater from a channel more than 50 meters (about 164 feet) wide.

USGS photo by M. Zoeller

At 3:15 p.m. HST, on September 18, new eruptive fissures opened west of Nāpau crater. A monitoring camera deployed by HVO field crews with permission from Hawaiʻi Volcanoes National Park recorded “lava falls” cascading down the northwest walls of Nāpau Crater. Vigorous activity continued and by the morning of September 19, about two thirds of Nāpau Crater floor had been covered with new lava. As of 10 a.m. HST on September 20, phase 4 eruptive activity came to an end. HVO lowered the volcano status from WATCH/ORANGE to ADVISORY/YELLOW on Monday, September 23.

Eruption analysis from HVO:

• The eruption in and near Nāpau crater had four eruptive phases between September 15 and September 20. The final eruptive activity from a small vent west of Nāpau Crater ended at about 10 AM HST on September 20.

• Lava flows from this eruption covered about 2/3 (500,000 square meters or 125 acres) of the floor of Nāpau Crater. In total, this eruption has covered more than 630,000 square meters (156 acres) of Nāpau Crater and areas to the west.

• Approximate lava effusion rates of roughly 5-15 cubic meters per second (6-16 cubic yards) were estimated during the most active part of the fissure eruption on September 19.