“Ballistic blocks” shot from Hawaii Kilauea volcano Halemaumau crater, Wednesday, for the the first time in nearly a century, the United States Geological Survey, USGS, said.
“This morning dense ballistic blocks up to 60 cm (2 feet) across were found in the parking lot a few hundred yards from Halemaumau. These reflect the most energetic explosions yet observed and could reflect the onset of steam-driven explosive activity.
Further observations are necessary to asses this interpretation. Additional such explosions are expected and could be more powerful,” USGS wrote in an advisory on Wednesday.
A 4.2-magnitude earthquake struck the region early Wednesday and another 3.5-magnitude temblor was felt around noon resulting in noticeable structural damage in buildings at the state’s Hawaii Volcanoes National Park.
As of Wednesday afternoon, the floor of the Kilauea caldera has dropped about 3 feet.
Because the tremors are shallow, they cause greater shaking and increase the potential for damage.
Plumes of sulfur dioxide gas at Kilauea have caused ‘vog’ and volcanic ash – which can be destructive to aircraft engines — and what prompted USGS on Tuesday to raise its aviation alert level to “red.”
USGS has warned that steam-driven eruptions could send ash as high as 20,000-foot and hurl boulders up to 12 tons up to a half mile from the crater.
EARLIER: Video: USGS Issues Aviation Red Alert For Hawaii’s Kilauea Volcano- The United States Geological Survey, USGS, has issued an aviation red alert warning due to a massive ash plume rising from a fissure on Hawaii’s Kilauea volcano. This warning from USGS means that “a major volcano eruption is imminent, underway or suspected with hazardous conditions both on the ground and in the air”
The red alert for airplanes in the region is being issued for the first time since the mountain suddenly ramped up its activity nearly two weeks ago. For airplanes, not only does the ash reduce visibility, but also more importantly volcanic ash can wreak havoc on jet engines.
Scores of people living near the volcano’s Halemaumau summit crater have already been evacuated. Now increased volcanic activity and a rising wall of ash has compelled the US Geological Survey to issue an aviation alert in the area.
A total of 20 fissures have appeared since Kilauea’s latest upsurge in activity became evident on May 3 in the housing subdivision of Leilani Estates. The eruption has destroyed 25 homes and covered 115 acres in lava.
Authorities on Tuesday announced the 20th fissure had opened in the Lanipuna Gardens subdivision adjacent to Leilani Estates.
According to the USGS, plumes of ash cloud as high as 12,000 feet are threatening visibility, with volatile wind conditions potentially bringing projectiles and volcanic fog in contact with aircraft.
Ash eruption at summit has increased in intensity. NWS radar and pilot reports show top of the ash cloud is as high as 10,000-12,000 feet above sea level. Ashfall and vog has been reported in Pahala (18 mi downwind), the Hawaiian Volcano Observatory, HVO, of USGS Volcanoes says.
“As of early this morning, eruption of ash from the Overlook vent within Halemaumau crater at Kilauea Volcano’s summit has generally increased in intensity. Ash has been rising nearly continuously from the vent and drifting downwind to the southwest. Ashfall and vog (volcanic air pollution) has been reported in Pahala, about 18 miles downwind. NWS radar and pilot reports indicate the top of the ash cloud is as high as 10,000 to 12,000 feet above sea level, but this may be expected to vary depending on the vigor of activity and wind conditions.” HVO of USGS Volcanoes said Tuesday afternoon.
Ash emission from the Kilauea summit vent will likely be variable with periods of increased and decreased intensity depending on the occurrence of rockfalls into the vent and other changes within the vent.
At any time, activity may become more explosive, increasing the intensity of ash production and producing ballistic projectiles near the vent.
Hawaii’s Kilauea Volcano Hazard Analysis[Ash cloud] The ashcloud is drifting downwind primarily to the southwest with the Trade Winds. Wind conditions are expected to change in the next 24 hours and other areas around Kilauea’s summit are likely to receive ashfall. [Ashfall] Ashfall has been reported in the community of Pahala, at locations along Highway 11 from Pahala to Volcano, and in the Ka’u Desert section of Hawaii Volcanoes National Park. [Other hazards] Ballistic projectiles may be produced should steam-driven explosions occur. Impacts will be limited to an area around Halemaumau. [Volcanic gas] Vog or volcanic air pollution produced by volcanic gas has been reported in Pahala.
United States Geological Survey, USGS Alerts Explained
NORMAL / GREEN : Non-erupting volcano is exhibiting typical background activity (including steaming, seismic events, thermal feature, or degassing), as long as such activity is within the range of typical non-eruptive phenomena seen at the volcano.
ADVISORY / YELLOW: Volcano is exhibiting signs of elevated unrest above known background activity.
WATCH / ORANGE: Volcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain OR an eruption is underway that poses limited hazards including no or
minor volcanic-ash emissions.
WARNING / ORANGE: Major volcanic eruption is imminent, underway, or suspected but it poses limited hazards to aviation because of no or minor volcanic-ash emissions (e.g., an eruption with only substantial lava flows and no risk of ash production).
WATCH /RED: Volcanic eruption is underway that poses limited hazards to ground-based communities but includes significant emission of ash into the atmosphere that could affect aviation (e.g. an A ash plume that does not yield significant ash fall onto ground communities but does drift into air routes.
WARNING / RED: Major volcanic eruption is imminent, underway, or suspected with hazardous activity both on the ground and in the air.
UNASSIGNED: Volcanoes where ground-based instrumentation is insufficient to establish that a volcano is in a typical background level (GREEN / NORMAL). When activity at such a volcano increases to the point of being detected by remote sensing, distant seismic networks, or eyewitness reports, an alert level and color code are then assigned accordingly. When activity decreases, the volcano goes back to UNASSIGNED without going through GREEN / NORMAL.
Volcanic Unrest is Persistent in Alaska and Hawaii
Mount Cleveland, located in the central Aleutian Islands, has been in a state of volcanic unrest since June 17, 2015. Explosive eruptions can send ash to altitudes hazardous to aviation.
Kīlauea Volcano on the Island of Hawai‘i has been erupting from its East Rift Zone nearly continuously since 1983. Lava flowing into the Pacific Ocean presents ocean entry hazards to visitors. A second eruption began at the summit of Kīlauea in 2008 where an active lava lake produces occasional explosions and gas emissions that create Statewide vog hazards.
Mauna Loa Volcano
Mauna Loa Volcano on the Island of Hawai‘i began showing signs of unrest in 2014, and the volcano alert level and aviation color code were raised on September 17, 2015. Elevated rates of earthquakes and ground deformation persist and HVO continues to monitor the volcano closely.