On June 12, 2009, the International Space Station’s orbit happened to take it over the Kuril Islands (northeast Japan).
The Kuril Islands were built by volcanic activity and still have active volcanoes. The most active is Sarychev Peak, located on the northwestern end of Matua Island.
Although Sarychev Peak hadn’t erupted since 1989, it was somewhat overdue for one, considering it had previously erupted in 1986, 1976, 1954, and 1946.
By a stroke of luck, the ISS was flying overhead when Sarychev Peak was in the early stages of its eruption on that June day in 2009, and captured a series of amazing images which were converted into the incredible GIF below:
The images (which you can view frame by frame courtesy of NASA here) are remarkable for a number of reasons.
Firstly, there was little to no shearing wind to spread and disperse the ash plume, so the ISS was able to capture crucial features of the eruption, like the pyroclastic flow at the base.
The small white cloud at the top of the ash plume is known as a pileus cloud. It was formed as the eruption rapidly pushed the moist air above the island upwards with the plume. As this moist air is pushed upwards, it cools and condenses, forming a cloud. When a pileus cloud in above an eruption or explosion, it’s called an “ice cap”.
One of the coolest features of these images has actually caused a bit of controversy in the science world. If you look around the edges of the images, you will see that the ash plume is emerging from a large circular opening in the clouds.
When the photo was originally published, NASA postulated that the hole was “punched” through the clouds by the upward shockwave of the eruption. But this explanation sparked a debate between meteorologists, geoscientists, and volcanologists who viewed the images. SInce then, two other possible theories have been proposed.
One is that the hole has nothing to do with the eruption at all. In areas where islands are surrounded by oceans with cool surface temperature, it is very common for sheets of clouds to form and drift along with the low-level winds.
When these clouds drift over an island, the moist air closer to the surface is pushed up by the island. Since the air above the marine layer (where the clouds form) is dryer and warmer than the air over the water, the portion of the cloud over the island evaporates, leaving a hole.
The final theory is that as the ash plume rises, the air above it flows down its sides, like water flowing off the back of a surfacing whale. As this air falls, it tends to warm, which could also cause an evaporation of the clouds around the volcano plume.
Whatever the reason, I think we can all agree that watching a volcano erupt from space is a truly mesmerizing site.
Check out the original post from NASA’s Earth Observatory here.