Volcano day!

Volcanoes are fun for kids to learn about. They like to see videos of erupting volcanoes (simply search for them on You Tube). My son also likes to talk about them because they are fascinating. I think they are pretty cool too, so today’s lesson focused on volcanoes. I was unsure how much of the lesson he would sit through and do, but to my surprise, he lasted for 45 minutes doing the first set of activities and then wanted to learn more after lunch. So after lunch we browsed around the various volcano websites and did more reading and learning (a bug thank you to the SDSU geology department for their page).

First we wrote the word volcano on a blank sheet of paper. Then we watched videos of volcanoes erupting on the Internet. I had him, on the same page he wrote the word volcano, then draw a volcano. After he got to do something active about volcanoes, we settled in for our lesson.

We learned about parts of a volcano using this picture. We also learned about how eruptions work, the different types of volcanoes, and some history of volcanoes. The SDSU website was really helpful. They even have various little tests after each section that we did. Lastly, they had a volcano crossword. Crosswords are fun. Since he’s still new to writing, we tend to do them this way: I read the clue and he gives me the answer. Then we spell it together as I write it in. This worked great for the volcano crossword.

Lastly, we made volcanoes. We took paper cups and surrounded them with a brown cone of construction paper. I put baking soda into the cup, and he poured vinegar into it. Presto – eruption. We did this for quite a while before the kids tired of this activity (yes, my 17 month old loved this one too). I had to change the brown paper a lot, but it was worth it to see their faces as they enjoyed the eruption.

These are the facts we focused on (I got them from the USGS website).

What is a volcano:

The word “volcano” comes from the little island of Vulcano in the Mediterranean Sea off Sicily. Centuries ago, the people living in this area believed that Vulcano was the chimney of the forge of Vulcan — the blacksmith of the Roman gods. They thought that the hot lava fragments and clouds of dust erupting form Vulcano came from Vulcan’s forge as he beat out thunderbolts for Jupiter, king of the gods, and weapons for Mars, the god of war. In Polynesia the people attributed eruptive activity to the beautiful but wrathful Pele, Goddess of Volcanoes, whenever she was angry or spiteful. Today we know that volcanic eruptions are not super-natural but can be studied and interpreted by scientists.

The Nature of Volcanoes

Volcanoes are mountains, but they are very different from other mountains; they are not formed by folding and crumpling or by uplift and erosion. Instead, volcanoes are built by the accumulation of their own eruptive products — lava, bombs (crusted over lava blobs), ashflows, and tephra (airborne ash and dust). A volcano is most commonly a conical hill or mountain built around a vent that connects with reservoirs of molten rock below the surface of the Earth. The term volcano also refers to the opening or vent through which the molten rock and associated gases are expelled.

Driven by buoyancy and gas pressure the molten rock, which is lighter than the surrounding solid rock, forces its way upward and my ultimately break through zones of weaknesses in the Earth’s crust. If so, an eruption begins, and the molten rock may pour from the vent as nonexplosive lava flows, or it may shoot violently into the air as dense clouds of lava fragments. Larger fragments fall back around the vent, and accumulations of fallback fragments may move downslope as ash flows under the force of gravity. Some of the finer ejected materials may be carried by the wind only to fall to the ground many miles away. The finest ash particles may be injected miles into the atmosphere and carried many times around the world by stratospheric winds before settling out.

How volcanoes erupt:

Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Because it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually some of the magma pushes through vents and fissures in the Earth’s surface. A volcanic eruption occurs! Magma that has erupted is called lava.

Some volcanic eruptions are explosive and other are not. How explosive an eruption is depends on how runny or sticky the magma is. If magma is thin and runny, gases can escape easily from it. When this type of magma erupts, it flows out of the volcano. Lava flows rarely kill people because they move slowly enough for people to get out of their way. Lava flows, however, can cause considerable destruction to buildings in their path. If magma is thick and sticky, gases cannot escape easily. Pressure builds up until the gases escape violently and explode. In this type of eruption, the magma blasts into the air and breaks apart into pieces called tephra. Tephra can range in size from tiny particles of ash to house-size boulders.

Explosive volcanic eruptions can be dangerous and deadly. They can blast out clouds of hot tephra from the side or top of a volcano. These fiery clouds race down mountainsides destroying almost everything in their path. Ash erupted into the sky falls back to Earth like powdery snow, but snow that won’t melt. If thick enough, blankets of ash can suffocate plants, animals, and humans. When hot volcanic materials mix with water from streams or melted snow and ice, mudflows form. Mudflows have buried entire communities located near erupting volcanoes. Because there may be hundreds or thousands of years between volcanic eruptions, people may not be aware of a volcano’s dangers. When Mount St. Helens in the State of Washington erupted in 1980, it had not erupted for 123 years. Most people thought Mount St. Helens was a beautiful, peaceful mountain and not a dangerous volcano.

For our volcano coloring book we used this one from Crayola.

Here are some other great websites with information on volcanoes:

http://www.woodlands-junior.kent.sch.uk/Homework/mountains/volcanoes.htm

http://www.geology.sdsu.edu/how_volcanoes_work/

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