Hawaii’s Kilauea volcano, which began erupting dramatically in early May, shot a 12,000-foot plume of ash and volcanic smog into the air on Tuesday. According to Terry Sylvester of Reuters, officials have issued a red alert for airplanes flying over the area, along with an “unhealthy air” advisory for the community of Pahala, which is located 18 miles from the summit.
This is the first time that officials have put out an aviation red alert since Kilauea’s latest burst of activity began on Hawaii’s Big Island on May 3. As Scott Neuman of NPR explains, volcanic ash reduces visibility and causes damage to jet engines, creating a highly dangerous environment for airplanes.
“At any time, activity may become more explosive, increasing the intensity of ash production and producing ballistic projectiles near the vent,” the United States Geological Survey (USGS) warns on its website.
The ash and volcanic smog, or “vog,” is also posing a risk to residents as it drifts away from the eruption site. Vog is formed when noxious sulfur dioxide from a volcano’s summit and eruptive vents reacts with oxygen, sunlight, moisture and other gases in the atmosphere to form a haze of fine particles. According to the USGS, vog can exacerbate pre-existing respiratory conditions. Residents who live within reach of the ash cloud, which has traveled about 18 miles downwind, are being advised to stay indoors, CNN reports.
Additionally, according to CNN, some areas are affected by high levels of sulfur dioxide leaking from the 21 fissures that have opened since Kilauea’s latest eruption. On May 14, Hawaii County officials warned that air quality in the southeast area of Lanipuna Gardens had reached “condition red,” meaning that they posed an “immediate danger to health.”
“Severe conditions may exist such as choking and inability to breathe,” officials said.
Volcanic gas and lava from Kilauea has thus far led to the evacuation of 2,000 residents and destruction of 37 structures on Big Island. Footage from the region has shown lava spurting out of the volcano, oozing along the ground and swallowing cars.
Experts are worried that more dramatic developments could be in store. The oozing fissures are draining the lava lake on Kilauea’s summit; if the lava level falls below the water table, the inflow of water will vaporize, building pressure under a plug of fallen rocks and debris. Eventually, this increasing pressure could burst out of the volcano in what is known as a phreatic eruption, which threatens to hurl ash and rocks in the air.
"We've seen the waxing and waning [of volcanic activity over the past few days],” Michelle Coombs, a geologist at the Alaska Volcano Observatory, told local reporters after Tuesday’s eruption. “[I]t intensified today but it wasn't the big one."