On August 27, 1883 the Krakatoa island volcano erupted in Indonesia’s Sunda Strait. The scale of the volcanic eruption and resulting tsunami was cataclysmic. More than 36,000 lives were lost.
For more information click here for About.com 19th Century History and here for an Australian Bureau of Meteorology article.
by Victoria M. Johnson
The eruption of the Puyehue-Cordon-Caulle volcano chain has prompted the mass evacuation of thousands of residents in southern Chile. Located about 500 miles south of the capital, Santiago, the eruption has spewed volumes of smoke and ash. So far no lava flows have been observed.
Chile Volcano Eruption
As the strong smell of sulfur filled the air, officials said the volcano was spitting molten rock. Witnesses reported experiencing more than 20 earthquakes. No injuries have been reported.
“The Cordon Caulle (volcanic range) has entered an eruptive process, with an explosion resulting in a 10-kilometer-high gas column,” Chilean state emergency office ONEMI said. According to MSNBC, it was not immediately clear which of the chain’s four volcanoes had erupted because of ash cover and weather conditions.
The chain last saw a major eruption in 1960. Chile’s chain of about 2,000 volcanoes is the world’s second largest after Indonesia. Some 50 to 60 are on record as having erupted. Chile’s Chaiten volcano erupted in 2008 for the first time in thousands of years. Chile’s Llaima volcano, one of South America’s most active, erupted in 2008 and 2009.
Whether for a science fair or for an earth science class, the school project all kids look forward to is to make their own volcano. I remember having a tall stratovolcano in mind, and being horribly embarrassed by my flat-as-a-pancake shield volcano. My volcano was all the more wretched by the fact that red molten lava didn’t spew out of it like some of the other kid’s projects did.
Kids With Their Volcano
But what an exciting time that was at school. I learned about the different kinds of volcanoes, how volcanoes are created, what our planet is like inside, and the effects of volcanic eruptions. Kids even talked about volcanoes at recess. That didn’t happen at any other time of the year. I’ve included some links for you to help your child with their important science project, lest they end up like me. Click here for steps to learn how to make your own volcano. Click here to see how to make your volcano erupt.
If you’re at all like me, you enjoy watching disaster films. Asteroid collisions, volcanic eruptions, mega earthquakes, are all events I love to see (fictionalized—not the real thing). Today the Syfy Channel has a disaster film marathon. With movies like NYC Tornado Terror, Category 6: Day of Destruction, Megafault, and Volcano: Nature Unleashed, scientists and regular citizens scramble to prevent the ultimate disaster that will end the world. In these films earthquakes, volcanic eruptions, or extreme weather systems threaten the world as we know it.
Earthquake Fault
I examined what it is I love so much about these kinds of movies and here’s what I discovered. There are people out there who dedicate their lives to studying our planet—disaster films give them the recognition they deserve—as it is often their expertise that saves mankind. The threat of disaster or dealing with the aftermath of the disaster brings people together, giving a sense of hope for the future, that facing the worst the planet has in store for us, we will survive. I also like that sense of survival that comes out in these films, people have to use their wits to stay alive, they have to step up and be brave and do whatever it takes to live. Another thing I enjoy is the often thought-provoking question that many of these films ask. What about you? Share your thoughts on this topic.
Ash plume from Eyjafjallajökull
Updates from the Institute of Earth Sciences at the University of Icelandreport that at least 10 earthquakes have been located at Eyjafjallajökull since midnight. Most are less that magnitude 2. Measurements show continued horizontal displacement around Eyjafjallajökull volcano. Explosive activity has increased, and with considerable tephra fallout, the cinder cone continues to build. Dark ash plumes have been observed at hieight of 20,000 – 22,000 feet. Scientists have reported, “everything turned black”. The lava channels are about 30 – 60 m wide. And according to UPI, Iceland’s volcano roared back to life on Thursday. “The eruption has changed back to an explosive eruption, lava has stopped flowing and most of the magma gets scattered due to explosions in the crater,” the Icelandic Meteorological Office said.
Will more disruptions in air travel occur? Will Eyjafjallajökull volcano return to the eruptive intensity it displayed in April? Scientists continue to say that “there are no signs the eruption is about to end.”
Mount Fuji, a stratovolcano
Of the four types of volcanoes, let’s take a close look at the dramatic stratovolcano.
1. Frequent pyroclastic eruptions give stratovolcanoes their towering cone shape.
2. Eruptions can originate from the summit or flank vents.
3. Subduction-zone stratovolcanoes, like Mount St. Helens, typically erupt with explosive force.
4. Some of the most powerful and destructive volcanoes in human history have been stratovolcanoes.
5. Stratovolcanoes are the most common type of volcano.
6. Of Earth’s 1,511 volcanoes known to have erupted in the past 10,000 years, 699 are stratovolcanoes.
7. Some of the most beautiful mountains in the world are stratovolcanoes, including Mount Rainer in Washington, Mount Fuji in Japan, and Kamchatka in Russia.
8. Magma, from deep in the Earth’s crust, travels through a conduit within the stratovolcano, which becomes lava when it erupts.
9. Between eruptions stratovolcanoes can be quiet for tens of thousands of years, seeming extinct.
10. Many cataclysmic eruptions throughout history were stratovolcanoes, including Mount Pelee in Martinique, El Chichon in Mexico, Mount Vesuvius in Italy, and Krakatoa in Indonesia, causing catastrophic loss of life.
Eyjafjallajökull
Eyjafjallajökull is one of the largest volcanoes in Iceland. Only three eruptions are known at Eyjafjallajökull in historical times, one in 920 A.D., another in 1612 AD, and the most recent in 1821. But on March 20, 2010 Eyjafjallajökull exploded back to life.
According to scientists at the Institute of Earth Sciences Nordic Volcanological Center, today the eruption in Eyjafjallajökull has a continuing discharge of meltwater from Gigjokull Glacier due to ice melt caused by the volcano. Booming sounds have been reported as far as 32 km from the eruption site. While ash and steam rise to an elevation of 3.6 km (12,000 ft), ejected lava reached heights of 660 feet. Would we expect anything less from an active stratovolcano?
Scientists are monitoring Eyjafjallajökull with radar observations, GPS measurements, satellite images, seismic monitors, river gauges, aerial observations, and geologist’s inspections of tephra. Tephra is the term for materials of all types and sizes thrown into the air by a volcanic eruption.