It seems like we’ve had an uptick in volcanic activity based on all the news reports of late, but in reality, everything is proceeding at a normal pace. While there have been some new eruptions in the past few months, other eruptions are slowing down or ceasing altogether.
Take Kīlauea in Hawai’i. This very active and extremely hazardous volcano had been erupting continuously from 1983 through 2018, and during that time, deposited about 4.4 cubic kilometers of lava, destroyed numerous homes and roads, and added 439 acres of new land to the island. Then, in 2018, after a massive eruption of new fissures on the eastern flank of the volcano, the Pu‘u‘ō‘ō lava lake collapsed, and the volcano quieted… until this past December. At that point, the Halema‘uma‘u lava lake at the summit had refilled and began to erupt again. Now, that activity has also ceased, and the USGS has lowered the Volcano Alert Level from watch to advisory. Halema‘uma‘u no longer has any visible lava in the crater. It’s still hazardous and prone to eruption, so please follow all warnings if you do visit the park.
Kīlauea is a fairly easy to manage volcano. The eruptions are steady and slow, and you can get out of the way. That’s not always the case, especially with stratovolcanoes — those huge peaks like Mt. Fuji in Japan or Mt. Saint Helens in the United States or just about any Andean volcano. And when those volcanoes erupt, they can disrupt everything, including air travel. Such is the case with the eruption just before we went on break of Great Sitkin in Alaska.
This volcano explosively sent an ash cloud 4.5 kilometers into the air, and that led to the Alaska Volcano Observatory issuing an alert for aircraft to avoid the area. The fine particles of ash that volcanoes send up into the air are very rough and jagged and can destroy an airplane engine by basically eroding turbine blades and scratching landing lights and other gear, as well as blocking fuel nozzles and air filters. It’s not fun stuff to fly through, and while the eruption may only have lasted one to two minutes, it sent up enough ash to create an immediate hazard in the airspace above. Once the winds picked up the ash, and much of it settled back down on the volcano, the hazard dissipated. This was the first eruption of Great Sitkin since 1974. Welcome to the 21st century, volcano!
Speaking of 21st-century volcanoes, we have been covering the ongoing eruption on Iceland’s Reykjanes Peninsula since before it started, and we could do that thanks to the scientific efforts of the Icelandic Meteorological Office. The team there has been tracking the magma that led to this most recent eruption since December 2019, when a series of seismic swarms began. They managed to follow the magma by monitoring ground deformation and tracked five different intrusions as they worked their way around the region.
Then, in February, a magnitude 5.7 earthquake occurred followed by another swarm of more than 50,000 quakes, which we reported on at the time. This swarm helped the scientists at the Met Office find a corridor of magma that flowed underground for about three weeks. The quakes continued to help define the edges of the chamber. And then, all the quakes and deformation dropped suddenly. Within a few days, the current eruption, that we are all enjoying watching via webcam, began. Since that point, the Icelandic Meteorological Office has been helping the Icelandic government monitor the eruption area and keep people safe, despite all the videos, volleyball, and general shenanigans going on at the site.