USGS and their Hawaii Volcano Observatory (HVO) unit have upgraded the Volcano Alert Level from WATCH to WARNING and the Aviation Color Code from ORANGE to RED due to a new volcanic eruption at Kilauea on the Big Island of Hawaii. At roughly 3:15 pm local time / 9:15 pm ET, HVO observed eruptive activity in summit webcam images and from field reports indicating that an eruption has commenced within the Halema’uma’u Crater and on the down-dropped block to the east in Kilauea’s summit caldera. The eruption is contained to the summit caldera which is entirely within Hawaii Volcanoes National Park. There is no threat to residential areas from lava at this time.
According to HVO, the eruption was preceded by a period of strong seismicity and rapid uplift at the summit. There has been increasing earthquake activity in Hawaii in recent weeks. Today, USGS measured 54 earthquakes; over the last 7 days, there were 215. And over the last 30 days, USGS recorded 1,160 earthquakes in and around Hawaii’s Big Island, with most centered around the Kilauea volcano.
“The opening phases of eruptions are dynamic. Webcam imagery shows fissures at the base of Halemaʻumaʻu crater generating lava flows on the surface of the crater floor,” HVO released in an update. “The activity is confined to Halemaʻumaʻu and the hazards will be reassessed as the eruption progresses,” they added.
HVO will continue to monitor this activity closely and report any significant changes in future notices. HVO is also in constant communication with Hawaii Volcanoes National Park as this situation evolves; for now, the park remains open to visitors.
While Kilauea is erupting, HVO and USGS says things are quiet at Mauna Loa, which happens to be the world’s largest active volcano, and Hualalai which stands just east of Kona’s International Airport.
Mauna Loa erupted last November and December, sending lava down its slopes into an undeveloped/unpopulated area of Hawaii’s Big Island. HVO says data from Global Positioning System (GPS) instruments on Mauna Loa indicate there is slow inflation underway as magma replenishes the summit reservoir system, but gas and temperature data from a station on the Southwest Rift Zone showed no significant changes over the past month. “HVO continues to monitor the volcano closely and will issue another update in one month, or earlier should conditions change significantly,” they wrote in their last update.
Hualalai is even more quiet than Mauna Loa, with no noteworthy activity observed in recent weeks. Though Hualalai is not nearly as active as Mauna Loa or Kilauea, USGS says geologic mapping of the volcano shows that 80% of the volcano’s surface has been covered by lava flows in the past 5,000 years. In the past few decades, when most of the resorts, homes, and commercial buildings were built on the flanks of Hualalai, earthquake activity beneath the volcano has been low. In 1929, however, an intense swarm of more than 6,200 earthquakes rattled the area around the volcano for more than a month. The earthquakes were most likely caused by an intrusion of magma beneath the volcano. Two large earthquakes, each about a magnitude 6.5 event, destroyed houses, water tanks, stone fences, and roadways. “For these reasons, Hualalai is considered a potentially dangerous volcano that is likely to erupt again,” warns USGS in their last update on the volcano.
In the U.S., the USGS and volcano observatory units are 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.