Lava
Maybe you have played the game called “The Floor Is Lava.” It is very simple. Several friends are together at school, at a mall, at home, or wherever, and someone yells, “The floor is lava.” Everyone then scrambles as fast as they can to a surface other than the floor, such as a chair, bed, base of a lamp post, or car bumper. The last person to get off the floor (or ground) “burns up” in the lava, obviously losing that round of the game. It is a fun game, as long as the floor is not real lava. Real lava is melted (also called molten) rock that can reach temperatures of more than 2,000 degrees Fahrenheit. Needless to say, if the floor really was lava, the thin pads of rubber on the bottom of your shoes would not protect your feet.
Why are we talking about lava in an issue of Discovery magazine? On one occasion during the life of Jesus, He rode a donkey into Jerusalem. Crowds of people gathered along the road and worshiped Him. Many of the jealous Pharisees hated to see people worshiping Jesus, and they demanded that Jesus tell the people to stop. Jesus said to them, “I tell you, that if these should keep silent, the stones would immediately cry out” (Luke 19:40). Thinking about that idea is almost comical. Imagine rocks on the side of the road talking and calling out to Jesus. Rocks do not even have mouths! Thinking about little rocks with mouths might be funny, but Jesus’ statement helps us understand something profound and important. All things that God made, including the rocks, bring glory to Him and show the Creator’s awesome power.
And one type of rock that is especially good at “praising God” is lava. When you read the word “lava,” you most likely think of the blazing orange liquid that erupts from the cone of a volcano and pours down the volcano’s side like a burning river. You might know, however, that not all lava is still hot. When lava cools, it solidifies into patterns and chemical mixtures that have unique appearances. Rocks that are formed in this way are known as igneous rocks. The word “igneous” comes from the Latin word ignis, which means “fire.” An igneous rock is formed by fire. Lava is one of the most well-known types of igneous rock. Let’s look at the different kinds of lava.
1. Pahoehoe (puh-HOY-hoy). This fascinating type of lava runs like a thick liquid. As it cools, the outer surface forms a smooth, unbroken pattern so that it often has smooth wrinkles with rounded edges. It often forms into lava tubes. It is one of the most “satisfying” kinds of lava to look at.
2. A’a (Ah-ah). A’a lava looks very different from pahoehoe. It does not have a smooth texture at all. When it cools, it forms very sharp, jagged, individual pieces of rock called clinkers. These clinkers break easily and, even when completely cooled, are difficult to walk on due to their sharp edges. One pun about this type of lava is that it is named for the sound people would make if they walked across it barefoot: Ah! Ah!
3. Pillow lava is unique in that it forms underwater. Magma is hot, molten rock that is under the surface of the Earth. It is called lava when it breaks through Earth’s crust. Much of the lava that comes through the crust of the Earth is in very deep water under the oceans. In such waters, the temperature can be extremely cold, almost freezing. When lava seeps out of the ocean crust, the cold water quickly cools the surface and forms “bubbles” of rock that often resemble balloons or pillows, which is where this lava gets its name.
4. Blocky lava does not have a very scientific name, but it is easier to say and spell than pahoehoe, and the name describes it well. When this lava cools, it is similar to a’a lava in that it forms individual units called blocks (not clinkers). The major difference between it and a’a is that the blocks have smooth surfaces and are much larger than clickers, often reaching several feet across instead of a few inches.
5. Columnar lava gets its name from the unique column structures that form. As the lava cools, the rock shrinks and creates intense pressure. This pressure causes the cooling rock to crack, often in upright columns that have a six-sided, hexagonal structure. This process is called columnar jointing. One well-known example of this process is the huge rock formation known as the Devil’s Tower in Wyoming. It is a national monument that is 867 feet tall and has a flat top that is about the size of a football field. It is primarily composed of columnar lava.
6. Blue lava is fascinating, but don’t let it fool you. It is not really lava. That’s right, blue lava is a misnomer. The word “misnomer” means that the name does not tell what the thing actually is. Blocky lava is not a misnomer at all because it perfectly describes what it names—lava that is blocky. Blue lava is a misnomer, because the name fools you into thinking it is something that it is not. While it is blue, it is not lava, but it does look like it. Certain volcanoes around the world, such as the Kawah Ijen volcano in Indonesia, have high levels of sulfur that are under extreme pressure. The pressure turns the gas into a liquid. When the gas spews out of the crust around the volcano, it catches on fire and burns with a bright, electric blue color. The burning, liquid gas snakes along the ground like lava does, but it does not cool and form into rock. It simply burns up.
When you read and study about lava, you are dealing with the scientific field of geology. Geology is the study of the physical structures of the Earth such as rocks and dirt. The prefix “geo” means “earth” or “land.” The suffix “ology” means “the study of.” Geology is the broad field that deals with all rocks, not just lava. If you wanted to study lava more, you could become a specialized geologist known as a volcanologist, who would study volcanos and their geology, including lots of time spent studying lava. Psalm 111:2 says: “Great are the works of the Lord, studied by all who delight in them.” The more we study the planet that God designed for us, the more we see His awe-inspiring power and majesty.
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