[Note: At the bottom of this post is a gallery of more amazing pictures of volcanoes taken from space.]
Sometimes, the best way to observe the Earth is to get off it. It really helps if you want to solve some mysteries.
And scientists had a good one on their hands in recently. You should really read the journal of science journalist Rebecca Priestly, who reported on all this first hand, but here's a summary. On August 9, the crew of the HMNZS Canterbury were on a scientific voyage in the Pacific when they got word to change course. A huge anomaly was reported near their position, and it looked like it might be a gigantic floating "raft" of pumice, possibly from an undersea eruption. They got samples, and sure enough it was pumice. Such rafts have been seen before from other volcanic eruptions.
But what volcano was at the root of this one? Early guesses were that it was from Monowai, which had recently erupted in early August. But satellite imagery taken on July 19 - weeks earlier - pinpointed the location of the raft's origin:
[Click to hephaestenate.]
This image, taken by NASA's Terra Earth-observing satellite, shows the eruption of the Havre Seamount, located a few hundred kilometers northeast of Auckland, New Zealand. The plume is clearly visible. The gray patch right in the middle of the picture is the floating island of pumice. To the left of the plume is teal water, stained by ash. The volcano itself is more than a thousand meters under the sea's surface, but the eruption was strong enough to break through. At the time this image was taken, the raft was already about 15 kilometers (9 miles) long. It eventually grew to more than 20,000 square kilometers (about 10,000 square miles).
This area of the ocean is very, very large, and without satellite images the exact location of this volcano would have been very difficult to spot. Scientists from Tahiti and New Zealand were able to connect earthquake reports on July 17 and 18 to the event (even though they occurred long before the raft was first sighted), and then other scientists were able to find the above image in the Terra archives. It took collaboration, people from around the world, and the open nature of science to be able to find the culprit volcano behind this mysterious event.
Science! Solving mysteries we otherwise couldn't! I love this stuff.
Image credit: Jeff Schmaltz, LANCE MODIS Rapid Response Team at NASA GSFC
Bad Astronomy Gallery
(click any image to see it full size)
Volcanoes From Space Part 2
Volcanoes are among the most magnificent geologic structures on Earth, but sometimes the best view is from above Earth. This gallery features beautiful and fascinating images of volcanoes and eruptions taken from satellites orbiting our planet. It's actually the second such gallery I made; here is the first one (scroll to the bottom to see it). Click the images to see bigger versions and/or get more information about them.
Fire and Ice
Onekotan island is a 50-kilometer-long volcanic double caldera in the Russian federation, in the western Pacific. A caldera is a depression that form when a magma chamber under the volcano collapses, creating the crater. The huge caldera on the left, called Tao-Rusyr, has filled with water since its collapse, and a new volcano - krenitzyn -- is now building up once again. This picture, taken in January 2011 by an astroanut on the International Space Station, is a study in contrasts. The frigid snow covering the volcanic island belies the terrible power and heat below.
Verdant volcano in a silvery sea
I love this shot of the south Pacific Tinakula volcano as seen by the Earth Observing-1 satellite. Tinakula is only sporadically active, and EO-1 caught a plume of steam and some ash from a mild eruption from February 2012.
But it's the water that makes this image so odd and lovely. It's actually natural color; the sunlight is glinting off the water, giving it that silver sheen.
Image credit: NASA/Jesse Allen and Robert Simmon (Earth Observatory)
A New Volcano Parts the Red Sea
Off the coast of Yemen, in the Red Sea, are a chain of islands called the Zubair Group. Two of them, Haycock (left) and Rugged (right) are about a kilometer long. Things were pretty quiet there until December 2011, when suddenly a new volcano erupted from the water!
Holy wow! I had no idea that area was volcanic, but it turns out it's a rift zone, where tow continental plates are separating. Earthquakes are relatively common, and then of course entirely new volcanoes sometimes pop up, too.
Now there's a way to part the Red Sea.
Image credit: NASA Earth Observatory/Jesse Allen, using EO-1 ALI data provided courtesy of the NASA EO-1 team.
Go with the (new) flow
Bagana volcano is in a very remote part of Papua New Gunea. Located far from towns and cities. While it may hide from human eyes, it can't from our robotic ones: the Earth-Observing-1 satellite caught Bagana erupting in May 2012. The dark brown lava flow to the upper right occurred sometime after March 2011. It's so new there hasn't been time for vegetation to grow on it, even in that tropical climate. The volcano is very active; you can see several older flows that are tinged grren with plant life. Satellites are critical for observing and understanding volcanic activity, especially in hard-to-reach locations.
Image credit: NASA/Jesse Allen and Robert Simmon using EO-1 ALI data
Volcano in Teal
The Canary Islands are a volcanic chain off the coast of Morocco, and geologically are very much like the Hawaiian islands. They're still active, too: a new volcano is being born even as we watch! Off the westernmost tip of the chain, an as-yet unnamed volcano has been erupting since October 2011. As of March 2012, the peak is still more than 100 meters below the surface of the ocean, but it's growing. By 2014 or so we may have to add a new island to the map of the Canaries.
Image credit: NASA Earth Observatory/Jesse Allen and Robert Simmon, using EO-1 ALI data
The icy swirls of Ostrov Shikotan
Off the eastern coast of Russia and north of Japan is an amazingly long 1300-km volcanic archipelago called the Kuril Chain. The weirdly rectangular Ostrov Shikotan is at the southern end, and has two extinct volcanoes on it. Tken in February 2011 by the Earth Observing-1 satellite, this photo shows icy water blown by opposing winds swirling around the island.
I love pictures of volcanoes from space, but this one is among my very favorites.
Image credit: NASA/Jesse Allen and Robert Simmon, using EO- ALI data provided courtesy of the NASA EO-1 team
Double your volcanic paradise
Tahiti is known as a tropical paradise for good reason, but the island is actually made of two volcanoes connected by a narrow and short isthmus. The larger one, Tahiti-Nui, is older, with lava rocks dated to 1.7 million years ago. Tahiti-Iti, the smaller one, has lava less than a million years old.
Both shield volcanoes have collapsed, and heavy erosion from rainfall has radically changed their appearance from all that time ago when they formed. This Landsat 7 image makes all that very clear... though I imagine from ground level it's far, far tougher to see.
Credit: NASA Earth Observatory image by Jesse Allen and Robert Simmon, using Landsat data from the U.S. Geological Survey.
Angling in on the edge of the abyss
Some of my favorite shots of volcanoes from space are not from satellites, but from the International Space Station astronauts. Most satellites look straight down, but astronauts suffer from no such limitation. This view of the Pagan volcano in the Marianas islands was taken in March 2012, when ISS was hundreds of kilometers south of the volcano. The narrow island actually has two volcanoes; one at each end separated by that isthmus. This area is where the Pcific plate is subducting under (going beneath) the Phillippine plate, which causes a lot of volcanic activity. It's also, not coincidentally, the location of the Mariana Trench, the deepest point in the Earth's crust.
Image credit: NASA
Water and ash
The Kamchatka peninsula is familiar to anyone who played the game Risk as much as I did as a kid: it's at the extreme northeast end of the Asian continent. It's also the home of many volcanoes, including Kizimen, which which has been erupting more or less continuously since December of 2010 -- after eight decades of rest.
The plume is white and tan, meaning it has water vapor in it as well as ash, and fresh ash falls line the flanks. These may also be from pyroclastic flows - torrential waves of burning hot ash which plow down the slopes at hundreds of kilometers per hour.
NASA Earth Observatory image by Robert Simmon, using data from the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.