USGS scientists with the Hawaiian Volcano Observatory (HVO) have decided to elevate the alert / code level at Kilauea Volcano on Hawaii’s Big Island to ORANGE / WATCH. According to HVO, the intrusion of magma that began on Friday in Kīlauea’s middle East Rift Zone continues, increasing the potential of an eruption in this region.
The HVO is observing a noteworthy earthquake swarm at the summit of the Kilauea Volcano on the Big Island of Hawaii. While the volcano isn’t erupting at this moment, that could change in the days ahead.
“Intense and localized earthquakes between Maunaulu and Makaopuhi Crater, accompanied by ground deformation patterns indicative of underground crack growth began at approximately 6 p.m. HST on September 14, 2024,” HVO scientists wrote in their latest update. “While the intensity of earthquake activity has decreased, continued ground deformation changes show that magma is still moving beneath the ground from summit storage chambers to the area between Maunaulu and Makaopuhi Crater.”
Data acquired by the European Space Agency’s (ESA) Sentinel-1A satellite is showing ground deformation that is consistent with magma moving into the region. Colored fringes denote areas of ground deformation, with more fringes indicating more deformation. Each color cycle represents 1.1″ of ground motion. The symbol in the upper left indicates the satellite’s orbit direction and look direction. The butterfly-shaped feature between Pauahi and Makaopuhi Craters on the middle East Rift Zone indicates ground surface extension over this time period as magma intruded underground. Increased earthquake activity associated with the intrusion of magma began around 4 pm HST on September 14 and is ongoing as of the afternoon of September 15, though it has decreased in intensity.
The largest earthquake during the magmatic intrusion, a magnitude 4.3 in the south part of Kaluapele, was associated with slip along one of the outer caldera faults, which USGS says is a consequence of stress changes due to the intrusion.
Scientists believe fresh any fresh activity with Kilauea will remain inside Hawaii Volcanoes National Park and not move into private property like it did in 2018. However, HVO / USGS scientists will continue to monitor the situation closely so residents and visitors to Kilauea and beyond are kept safe from the increasing seismic activity there.
USGS equipment detected an increase in earthquake activity beneath the south part of Kīlauea summit caldera, within Hawaiʻi Volcanoes National Park, within the last 24 hours. The activity began around 4:30 pm HT on August 23 and continued through the night and into the early morning of August 24, 2021. At about 1:30 am this morning, the swarm of earthquakes intensified in this region and was accompanied by an increase in the rate of ground deformation recorded by the Sandhill tiltmeter, just to the west of the earthquake swarm location. “These observations may indicate a small dike intrusion of magma occurring 0.6-1.2 miles beneath the south caldera,” HVO said in an update this morning. “Over 100 earthquakes have been recorded as of 2:30 am on August 24; the largest recorded earthquake was magnitude 3.3 with the majority of earthquakes less than magnitude 1. Small earthquakes are continuing at a rate of at least 10 detected earthquakes per hour. Currently, webcams show no evidence of lava at the surface.” HVO added that their scientists will continue to monitor the situation and will issue additional messages and alert level changes as warranted by changing activity.
Starting around 9 pm and continuing until 10 pm local time last night, infrasound instruments detected a strong signal typical of gas or steam venting and seismometers in the middle East Rift Zone are recording weak, sustained low frequency tremor. However, HVO’s webcam network has not shown any evidence of eruptive activity and GOES satellite data do not show any thermal anomalies at this time. Currently, strong rainfall in the area is complicating interpretation. In 2007, an intrusion in this area erupted a very small pad of lava approximately the size of half a football field, so it is possible a similarly small eruption could take place without detection in these conditions.
HVO is responsible for issuing Aviation Codes and Volcanic Activity Alert Levels. Aviation Codes are green, yellow, orange, or red. When ground-based instrumentation is insufficient to establish that a volcano is at a typical background level of activity, it is simply “unassigned.” While green means typical activity associated with a non-eruptive state, yellow means a volcano is exhibiting signs of elevated unrest above known background levels. When a volcano exhibits heightened or escalating unrest with the increased potential of eruption, it jumps to orange. Finally, when an eruption is imminent with significant emission of volcanic ash expected in the atmosphere or an eruption is underway with significant emission of volcanic ash into the atmosphere, the code becomes red. Volcanic Activity Alert levels are normal, advisory, watch, or warning. As with aviation codes, if data is insufficient, it is simply labeled as “unassigned.” When the volcano is at typical background activity in a non-eruptive state, it is considered normal. If the volcano exhibits signs of elevated unrest above background level, an advisory is issued. If a volcano exhibits heightened or escalating unrest, a watch is issued while a warning is issued when a hazardous eruption is imminent.
With this activity at Kilauea, HVO has set the volcano to a ORANGE aviation code and a WATCH volcanic activity alert level. Nearby Mauna Loa, considered to be the world’s largest active volcano is at GREEN / NORMAL.
