Showing posts with label Volcano. Show all posts
Showing posts with label Volcano. Show all posts

Friday, March 25, 2011

The Volcano Next Door.

Scientists descend to a fiery lava lake to protect a Congolese city in its path.
By Michael Finkel
Photograph by Carsten Peter
"excerpt comes from the April issue of National Geographic magazine" (http://ngm.nationalgeographic.com/2011/04/nyiragongo-volcano/finkel-text)

When? This is the question that has brought two of the world's leading volcano scientists to the center of Africa; it's the question that haunts a team of Congolese seismologists; it's the question that may determine the fate of close to one million people. When will Nyiragongo erupt?
Nyiragongo is a two-mile-high volcano towering over the eastern edge of the Democratic Republic of the Congo (DRC)—one of the most active volcanoes on the planet and also one of the least studied. The chief reason for the lack of research is that for the past 20 years the eastern DRC has seen nearly constant warfare, including a spillover of the massacres in neighboring Rwanda. One of the largest United Nations forces in the world, some 20,000 troops, currently maintains a fragile, and often broken, peace.
At the base of the volcano sprawls the city of Goma, growing by the day as villagers from the countryside seek refuge from rebel and government forces. An estimated million people are now crammed into Goma.


Fig.1The lava at Nyiragongo is made of an alkali-rich volcanic rock; its unusual composition may be a factor in the lava's fluidity.Photo by Carsten Peter/National Geographic

Fig.2 Photographer Carsten Peter tests the thermal suit that Sims used to get close to the lava lake. "It can protect you from the radiant heat, but if you get hit with a lava splatter, the force will likely kill you," he says. For 30 years Peter has explored volcanoes around the world. "Seeing at close range the primal forces that shaped the planet can be hypnotic. You cannot allow yourself to fall under a volcano's spell, especially one as unpredictable as Nyiragongo. That can be a fatal mistake."Photo by Carsten Peter/National Geographic
Fig. 3 With temperatures around 1800 degree F., the lava is wildly erratic. As molten rock meets the air , it cools and forms plates on the lake's surface.Photo by Carsten Peter/National Geographic

http://ngm.nationalgeographic.com/2011/04/nyiragongo-volcano/peter-photography

The above photos are "in the April 2011 issue of National Geographic magazine, on newsstands March 29."

Friday, June 26, 2009

Striking view of Sarychev volcano (Russia’s Kuril Islands, northeast of Japan).



A fortuitous orbit of the International Space Station allowed the astronauts this striking view of Sarychev volcano (Russia’s Kuril Islands, northeast of Japan) in an early stage of eruption on June 12, 2009. Sarychev Peak is one of the most active volcanoes in the Kuril Island chain and is located on the northwestern end of Matua Island. Prior to June 12, the last explosive eruption had occurred in 1989 with eruptions in 1986, 1976, 1954 and 1946 also producing lava flows. Commercial airline flights were diverted from the region to minimize the danger of engine failures from ash intake. This detailed photograph is exciting to volcanologists because it captures several phenomena that occur during the earliest stages of an explosive volcanic eruption. The main column is one of a series of plumes that rose above Matua Island (48.1 degrees north latitude and 153.2 degrees east longitude) on June 12. The plume appears to be a combination of brown ash and white steam. The vigorously rising plume gives the steam a bubble-like appearance; the surrounding atmosphere has been shoved up by the shock wave of the eruption. The smooth white cloud on top may be water condensation that resulted from rapid rising and cooling of the air mass above the ash column, and is probably a transient feature (the eruption plume is starting to punch through). The structure also indicates that little to no shearing winds were present at the time to disrupt the plume. By contrast, a cloud of denser, gray ash -- most probably a pyroclastic flow -- appears to be hugging the ground, descending from the volcano summit. The rising eruption plume casts a shadow to the northwest of the island (bottom center). Brown ash at a lower altitude of the atmosphere spreads out above the ground at upper right. Low-level stratus clouds approach Matua Island from the east, wrapping around the lower slopes of the volcano. Only about 1.5 kilometers of the coastline of Matua Island (upper center) can be seen beneath the clouds and ash.
Image Credit: NASA