Name:______________________ Weekly Homework: March 2 – March 9 A. Math: There will be math homework Monday - Thursday this week. B. _____Writing: Write a short story, either fictional or real, with one of the themes we discussed in class this past week. Themes: honesty, compassion, perseverance, cooperation, loyalty, kindness, courage, acceptance, patience, and forgiveness. C. Reading Comprehension: Volcanoes! Read the attached short articles about Volcanoes. Answer the questions. The Word Search is optional. D. ___ READ, READ, READ and complete the Home Reading Log. A minimum of 125 minutes per week is required. These minutes will go toward the Penny Creek 1,000 minute reading challenge! FRIENDLY REMINDER: GET IT SIGNED BY A PARENT. Home Reading Log NAME: Date Book Title (Remember to Capitalize titles) Number of min. A minimum of 125 minutes. All minutes will go toward the Penny Creek 1,000 minute reading challenge! Total minutes read this week __________________ Parent Signature ____________________________ Three Kinds of Volcanoes SHIELD VOLCANOES have gentle slopes, like a shield, because they are made of many layers of a kind of volcanic rock that flows easily when melted. This kind of rock is called BASALT. When it flows out of the vent it forms thin layers sloping away from the crater. Some shield volcanoes get to be very large. The volcanoes which make up the islands of Hawaii are shield volcanoes. CINDER CONES are made of bits of kind of volcanic rock called ANDESITE. Sometimes there are bits of basalt, too. These bits of rock are called cinders. They may be tiny, like ash, or larger, like gravel. They get blown out of the vent and harden in the air. When they land, they pile up around the crater to form a steep cone. Cinder cones are often smaller than shield volcanoes, and they wear away easily. COMPOSITE CONES are made of layers of cinders between layers of lava. The layers of cinders make the sides steep, and the layers of hardened lava keep them from wearing away fast. Many famous volcanoes like Mr. St. Helens in the State of Washington are composite cones. 1. Composite cones are often bigger than cinder cones because. a. they are older and have had more time to grow b. the hardened lava keeps them from wearing away fast. c. they grow where there are already mountains. 2. After a shield volcano erupts, it usually is a. a little higher because most of the lava runs down the sides of the volcano. b. a lot higher because most of the lava piles up around the vent. c. lower because the top of the volcano will cave in. 3. Mr. McKinley in Alaska is one of the world’s highest volcanoes. From its size we can tell that a. everything in Alaska is big. b. Mt. McKinley is a cinder cone. c. Mt. McKinley is not a cinder cone. What Makes Volcanoes Explode? When you look at pop in an unopened bottle, you can see a few bubbles of gas in it, but not many. Shake the bottle and take off the pressure cap. Out comes thousands of bubbles bringing a shower of liquid with them. The pressure kept the gas dissolved in the liquid. When you took off the cap, the pressure of the gas made it suddenly come out of the solution and explode out of the bottle. The hot magma underneath volcanoes has a lot of gas dissolved in it, too. The rocks on top press down and keep the gas dissolved. Then when something takes the rocks away, the gas suddenly comes out of solution and explodes out of the volcano. Rocks and hot lava come with it. Cinder cones are more dangerous than shield volcanoes because the magma under cinder cones is made mostly of a kind of rock called ANDESITE which can dissolve a lot of gas. This makes cinder cones very explosive. The magma under shield volcanoes, like those in Hawaii, is made mostly of a kind of rock called BASALT which can dissolve only a little gas. This makes shield volcanoes less explosive. When shield volcanoes erupt, people have time to get out fo the way because the magma doesn’t explode. It flows. 1. Cinder cones are more explosive than shield volvanoes because a. the magma under them can’t absorb much gas. b. the magma under them can absorb a lot of gas. c. the magma under them is hotter than the magma under shield volcanoes. 2. When the magma under a volcano is mostly andesite, the lava that comes out during an eruption will a. flow out. b. explode out. c. bubble out. 3. From the story you can tell that a. pop got its name from the way it pops out. b. there are more cinder cones than shield volcanoes on earth. c. cinder cones are different from shield volcanoes because the magma under them dissolves gas differently. Deep Under A Volcano No one can dig under a volcano to see what is underneath, but scientists who study volcanoes have learned many ways to make guesses and check them out. Many scientists agree that deep underground there is rock so hot that it is melted. This melted rock is under so much pressure from all of the rocks above that it is pushed up through cracks toward the surface of the earth. The melted rock is called MAGMA when it is still below the surface. The pressure keeps it stiff, about like toothpaste, even though it’s melted. If the magma is squeezed clear to the surface, we say the volcano ERUPTS. Now the magma is not under pressure any more. We call this magma that has come to the surface LAVA. Lava is not under pressure the way magma is, and this changes it. Now it can flow. Some kinds of lava, while red hot, are almost as runny as water. The lava that makes the volcanoes of Hawaii is this runny kind. The lava that is making a new dome in the Mt. St. Helens crater is rather stiff even when it is red hot, so instead of flowing it pushes up into a dome shape. Look at the volcano in the picture and at the magma underneath it. You can see that some of the magma is coming out at the top of the big cone, and some of it is coming out through a crack in the side of the big cone and making a little cone. Mt. Shasta in California has a smaller cone on one side made this way. The smaller cone is names Shastina. 1. Magma is stiffer than lava because a. it is hotter. b. the rocks above press down on it. c. it has stones in it and that makes it thicker and stiffer than lava. 2. If lava flows through a forest, a. the trees will become petrified. b. the trees will burn. c. the trees will stop lava. 3. From the story you can tell that a. scientists have been reading a lot of books about volcanoes. b. scientists have been digging underneath volcanoes. c. scientists have been studying volcanoes carefully.