NASA ISS photo of Raikoke in eruption taken June 22. Active plume with water vapor collar at the base. Water vapor collar at the base may be due to ambient air sucked upwards with the plume. Alternately, it may be due to interaction of pyroclastic flows with surrounding sea water. Image courtesy NASA Earth Observatory.
Raikoke volcano in the Kurils erupted around 0400 L on June 22, 2019. The eruption was observed by Space Station astronauts, the MODIS instrument on NASA’s Terra satellite, GOES West, Suomi NPP / VIIRS, Copernicus Sentinel5P and Himwari-8. There were at least nine distinct pulses of ash injection due to significant explosions. The plume was drawn eastward into a storm system making its way up the Aleutians. The most violent portion of the eruption sequence was over in less than 24 yours.
NASA Terra Satellite MODIS instrument cropped image of Raikoko in eruption. Prevailing winds at altitude west to east. Prevailing winds at surface east to west, though not as strong. Image courtesy NASA Earth Observatory.
NASA Earth Observatory, NOAA CIMSS, Volcano Discovery, Erik Klemetti at Rocky Planet, and Le Chaudron de Vulcain all provided outstanding imagery and near real time coverage of the eruption.
One of the things satellite and visual photography gives us is the ability to see volcanic plumes as they develop. Photographic coverage of this eruption was combined into animated GIFs and short videos similar to the multiple images of Sarychev taken from the Shuttle June 12, 2009. Over the course of the last decade, scientists are getting much better at it.
Animated GIF / video is the GOES West view of the eruption plume breaking through the cloud cover. There are nine total explosive pulses, six of them before the plume goes into continuous eruption. Once the continuous plume abates, it is followed by two final explosive pulses. Image courtesy NASA Earth Observatory.
Outside of various Twitter feeds linked in the Additional Information section, the NOAA CIMSS Satellite Blog has the best compendium of satellite observation products and animated GIFs of this eruption.
Raikoke Island prior to the June 22 eruption. Image courtesy Gizmodo.
Raikoke Island
Raikoke is a small volcanic island in the central Kuril islands, 16 km across the Golovnin Strait from Matua Island, home of Sarychev volcano which we covered in May. It is a remote island, with less than 150 people within 100 km of the island.
It is a circular island nearly 5 km in area, topping out at 551 m above the ocean surface. It has a crater on top 700 m in diameter.
Like most other islands in this part of the world, Raikoke is uninhabited and home to bird and seal rookeries. It is (was?) one of the five major Steller sea lion rookeries in the Kuril Islands. It is home to nesting populations of various sea birds.
Before and after images of Raikoke showing the change in size of the island. New material is visible all around the island. Multiple islands on the east side (image right) visible in the top photo are now connected to the main island by flow remnants. Images courtesy Sentinel via VolcanoPlanet on Facebook.
There were reports of 15,000 northern fur seals on the island in 1883. It took seal hunters only a decade to reduce that number to “a few scores.” Currently no fur seals reproduce on Raikoke.
Indigenous Japanese Ainu visited Raikoke with hunting and fishing parties. There was no permanent habitation on the island at the time of European contact. It was initially part of feudal Japan. Ownership went back and forth between Russia and Imperial Japan until the Kurils were captured by the Soviet Union in the latter stages of WWII.
Eruption
Raikoke Island is a small basaltic island that has not been particularly active over the last 400 years. Smithsonian GVP lists three previous eruptions, a VEI2 in 1765, a VEI 4 which removed the top third of the island in 1778, and a recent VEI 4 in 1924. The June 22 eruption has also been classified as a VEI4.
The most recent eruption began early morning on June 22. There were a series of at least nine explosions putting a plume as high as 13 km above the volcano. Six of the explosions were within the first half hour. The plume drifted to the east and was wrapped into a major storm system working its way along the western Aleutians. The eruption had a significant SO2 component that did not disperse and was visible via satellite observations as it wrapped around the storm’s center. Tropopause altitude at the time was 11 km, so the top of the plume made it into the stratosphere. CALIPSO data suggests parts of the plume may have reached 17 km.
The VaisalaGroup responded to a Klemetti Tweet with a note that almost 600 lightning events were detected since the start of the eruption.
In response, KVERT and SVERT raised the aviation color code to Red. 24 hours later, the leading edge of the plume had traveled 2,000 ENE. The Tokyo VAAC and Alaska Volcano Observatory also issued aviation warnings. In all, there were at least 40 flights diverted due to the eruption.
Drone image of smaller eruption from Raikoke taken June 23 by Nik Pavlov. Image courtesy Nik Pavlov via Le Chaudron de Vulcain, June 25.
Although the main event ended in over the course of the first 12 hours of eruption, plumes were still visible the next day rising 4.5 km above the volcano.
A passing ship sent out a drone that returned video and photos of the island. The entire island was covered in light colored ash, some of it up to several meters thick in places. In some locations, wave action interacted with the pyroclastic flow deposits causing steam explosions and emissions. Minor ashfall was reported 340 km NE by that evening.
Drone image of Raikoke taken June 23 by visiting ship. This photo shows extension of island via pyroclastic flow deposits. Block center left used to be a separate island. Image courtesy Nik Pavlov via Le Chaudron de Vulcain, June 25.
Ash plumes continued through June 25, though they were only 2 km high. Prevailing winds still carried the ash to the NW.
The eruption produced pyroclastic flows and ashfall that changed the shape of the island, growing it a bit at least for a little while.
Drone image of Raikoke taken June 23 by visiting ship. This photo shows extension of island via pyroclastic flow deposits. Image courtesy Nik Pavlov via Le Chaudron de Vulcain, June 27.
Tectonics
Volcano Hotspot previously covered tectonics of the Kuril Islands in our Ebeko, Sarychev and Simushir posts.
The short description of tectonics in this part of the world is that it is driven by the subduction of the Pacific Plate under the Okhotsk Sea plate. The Kuril Trench is offshore to the east with the movement of the Pacific Plate being about 8 cm/yr. Volcanic activity is all subduction driven and there are large megathrust earthquakes in the region.
Central Kuril islands. Raikoke and Matua are depicted center right. Kuril trench location also depicted. Image courtesy International Kuril Island Project.
Conclusions
Raikoke is an infrequently active volcano. When it erupts, it does get its money’s worth, with the three most recent eruptions all in the VEI 4 range. It is currently uninhabited and the eruption disrupted nesting grounds and rookeries for birds and seals at least for a while.
Timing of this eruption was also interesting, as there was another VEI 4 out of Ulawun in New Britain, PNG on the same day, leading some to opine that this was the first time two eruptions that large were observed on the same day.
Satellite image of Raikoke eruptive plume blowing to the east. Image from NASA EOSD/LANCE, GIBS/Worldview or Suomi National Polar-orbiting Partnership. Image courtesy NASA Earth Observatory.
Additional Information
https://www.universetoday.com/142667/eruption-of-the-raikoke-volcano-seen-from-space/
https://earthobservatory.nasa.gov/images/145226/raikoke-erupts
https://gizmodo.com/incredible-photo-from-the-space-station-shows-raikoke-v-1835837595
http://blogs.discovermagazine.com/rockyplanet/2019/06/22/big-blast-from-russian-volcano-raikoke/
http://cimss.ssec.wisc.edu/goes/blog/?s=raikoke
Spica
With the recent large earthquakes in Southern California and earthquake swarm south of the Coso Volcanic Field, I ran across a popular article on the Walker Lane where it is all taking place from last April. A decent popular treatment of the subject. Cheers –
https://www.wired.com/story/walker-lane-move-over-san-andreas-fault/
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Earthquake swarm at Coso continues with over 600 > M1.0. Quakes are considered distant aftershocks / triggered earthquakes and not connected to any volcanic activity. Update is at the link.
National news had a story about a single fatality out of the pair of earthquakes. A jeep on jacks fell down on its owner who was working on it at the time of the first quake. Accident was just discovered. Regards –
https://volcanoes.usgs.gov/observatories/calvo/calvo_activity_update_last10.html
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