Magma and Lava
- Language block #1
- Big 6 project
The World Book Encyclopedia vol. 12
As you will learn this whole web page is about lava. That is the purpose this was created. There are various things about magma and lava and you will learn them if you go to every link in this web page. If you would like to learn what magma and lava are and their difference go to What is Magma and Lava under the next few pargraphs.
Most people wonder how magma gets to the earths surface and why it is so violent. Well, I studied a lot, but finally found out that magma reaches the earthís surface because some gas bubbles in magma want to expand and rise, which forms a chain reaction. If you would like to learn more about how magma gets to the earthís surface go to: How Magma gets to the Earthís Surface?
A lot of people donít know what the earthís mantle is as mentioned in the last link. Many people donít know that it is made up entirely of rocks or that the mantle is the biggest layer in the earth. If you would like to learn more about the mantle go to: What is the Mantle?
When volcanoes erupt they can produce two very different kinds of lava. One is Aa lava and another is Pahoehoe lava. If you would like to learn more about the kinds of lava a volcano erupts go to: What are the two kinds of lava?
Lava can get extremely hot and so can magma. If you want to know the temperatures of magma and lava, and their range go to: How hot is Lava and Magma?
What materials can resist lava is a frequently asked question. Not a lot of materials can withstand lava. If you would like to know what some materials that can resist lava are then go to: What substances can resist lava?
I like many other people have wondered how long it takes for lava to turn into stone. If you would like to learn how long it takes for lava to turn into stone go to: How long does it take for lava to turn into stone?
Do you know what happens after lava erupts into stone? It mixes in with a few rocks and makes a type of lava (not kind of lava). For more info go to: What happens after lava erupts?
Now I have gotten to a point that anyone who hasnít studied lava for a while doesnít know. The final stage of lava and magma. If you would like to learn about the final stage go to: The final stage.
What is magma and lava?
Magma is molten rock. In other words melted rock. When magma finally reaches to the earthís surface it mixes in with steam and gas that is around it and it turns into lava. A lot of people donít know the difference between magma and lava, but there is it is just that it canít be seen with the naked eye. Lava is slightly cooler than magma, glows a different color, and it is made up of different substances (because of the steam and gas added to it). When gas and steam was mixed in with magma it changed some chemicals.
How does magma reaches the earthís surface?
Magma has a lot of gas bubbles inside it that want to expand and also rise causing pressure. When that pressure gets high enough the gas bubbles start rising and expanding taking the magma with it. When the gas pressure gets even higher it starts making a chain reaction that constantly makes the gas pressure rise. Once magma has reached the bottom of a volcano the gas pressure is so high that the volcano leaks and magma comes pouring out causing a violent escape of magma. Once magma has reached the earthís surface the gas bubbles can expand up to 50 times faster then when magma was in the mantle. And that is how an eruption occurs.
What is the mantle?
The planet earth has four layers in it. The first layer is the very solid inner core, the oozy outer core, the mantle which not only the largest layer, but it is filled with rocks, magma, and other solids, and the thinnest of them all the crust. The crust is by far the thinnest layer on earth. Fossil fuels such as petroleum, coal and natural gas are found here. Now that you know a little about all the layers I will concentrate on the mantle only. No man or woman has ever gotten even half way down the mantle. No living thing can survive down there. If you dig about 5 mile deep in the bottom of the deepest part of the Pacific Ocean then you would probably hit the mantle. Probes that have been down there recorded a temperature of over 500 degrees Fahrenheit.
What are the kinds of lava?
When a volcano erupts it can produce two different kinds of lava. One kind of lava is Aa lava. Aa lava moves very slowly, makes its crust a lot faster than the other kind of lava and it is a lot more vicious than it. Aa lava temperatures are usually 100 too 200 degree centigrade (about 200 too 400 degrees Fahrenheit) hotter than any other lava. Aa lava is usually found in Hawaii, but can erupt at different places. The other kind of lava is Pahoehoe lava. Pahoehoe lava is very liquid like and can sometimes flow faster than a man can run. Pahoehoe lava produces its crust in a long period of time. This kind of lava can be found in various places of the world all of the time.
How hot can magma and lava get?
Pahoehoe lava temperatures usually range from 1000 too 1050 degrees centigrade (about 2000 too 2100 degrees Fahrenheit). Lava in Hawaii (Aa lava) usually ranges from 1170 too 1175 degrees centigrade. In other words about 2340 too 2350 degrees Fahrenheit, which is approximately 250 degrees Fahrenheit, difference between Aa lava and Pahoehoe lava. Magma temperatures can be various. Its temperature usually ranges from 700 too 1200 degrees centigrade which is a big range considering that Aa and Pahoehoe lava only have a range of 5 centigrade. Magma is about 2800 degrees Fahrenheit. The difference between Pahoehoe lava and magma is 600 degrees Fahrenheit apart in which Aa lava is only 400 degrees apart.
What substances can resist lava?
Not a lot of materials can withstand lava. The only materials that can resist it are those with melting points above 2,800 degrees Fahrenheit. I know what you are thinking and the melting point of a substance has to be over 2,800 because if not the substance will start too weaken until it is weak enough to melt. Some materials that have melting points over 2800 are stainless steel, titanium, cooled lava or magma, and many more. They all have melting points higher than 2800. When materials start to melt they usually turn gray or black.
How fast can a lava flow go?
Lava flows are streams of lava that pour from an erupting vent. Erupting vents are open gaps in a volcano that streams of lava can go through. In time that gap gets smaller and smaller, because after lava gets stuck in the gap it cools making the gap slightly smaller making the amount of lava flows less every time the volcano erupts. Now that you know what a lava flow is I will talk about its speed. The speed of lava depends on how steep the hill the lava is going down and how much silica (a very thick crystal) it has. The steeper the hill the faster the lava flow the more silica the slower the flow. The condition of lava flowing is so low that it is but 100000 that of water making lava scarcely flow at all. The fastest flow ever recorded in Hawaii (Where Aa lava is) was 10 KPH through a thick forest. Sometimes lava can flow up to 35 KPM and sometimes it only flows a few inches a day.
How long does it take for lava to turn into stone?
Usually fresh lava glows red hot to white hot making it very hard for lava to cool down. Lava always cools at different rates. It all depends on how fast the lava flow is. The faster the flow the slower the lava cools because the crust always wears out the slower the flow the faster lava makes its crust because it doesnít wear out the crust as much. If a lava flow is to fast lava has to flow until it reaches land that is less steep. When a lava crust finally forms it cools a little more until it turns into stone because the crust never really means it is a rock yet.
What happens after lava erupts?
When lava goes over rocks they can mix in with it and turn into three different kinds of lava. Lava containing 65 too 75 % of silica is considered Rhyolite lava. Rhyolite lava melts at a lower temperature and it is lighter in weight and color. Lava containing 50 too 64 % of silica is considered Andesite lava. Andesite lava is a large group of rocks that can be found in any volcano site and have a melting point dramatically under 2800 degrees Fahrenheit. Lava containing 50 percent or less of silica is considered basalt lava (basaltic lava). Basaltic lava can produce two different kinds of lava (Aa lava and Pahoehoe lava) both found in Hawaii.
What is the final stage of lava?
All kinds of lava can turn into pumice, but Rhyolite lava usually produces it because Rhyolite lava is the most common kind of lava. Pumice is a rock, which is mostly used for polishing and cleaning metal, wood, and other surfaces. Rhyolite lava turns into white pumice while Andesite lava turns into yellow or brown pumice. Basaltic lava usually turns into black pumice, but sometimes it turns into a blend of dark colors. Pumice is usually found in Germany, New Zealand, Greece, Hungary, Italy, Ireland, and the Canary Islands. There might be some other places that pumice can be found, but these are the main places where pumice is found, because there are more volcanoes in these areas.