Roll and Read (Yellow) 1 2 3 4 5 Many small earthquakes shook the volcano. The force from that pressure created a bulge in the volcano. The pressure also caused the volcano to tremble. Lava inside the volcano built up pressure. The scientists spent a lot of time watching the bulge. The pressure could cause such a bulge. The pressure and the bulge it made scared the scientists more than any other warning sign. Winds carried ash from the eruption many miles to the east. It took many weeks to clean up all the ash that fell on the city. People had to wear masks to help them breathe. The rock and ash from the eruption rained like fireworks The volcano continued to tremble and erupt for weeks after the first eruption. Some of the plants and trees are growing more slowly than others. The mountain smoked like a chimney. Trees and plants were buried beneath ash and rock. The eruptions also made a crater, or shallow hole. More than years have passed since the eruption of 1980. Scientists estimate it will take more than two hundred years for the plant life of Mount St. Helens to completely grow back. After nine hours, the eruption finally ended. Scientists monitored the mountain carefully. When it erupted, Harry and his house were buried under tons of mud. It taught scientists many things about volcanoes. Since there are more plants and trees now, there is more for the animals to eat. They also monitored the steam and gas that rose from the mountain. Mount St. Helens is a volcano. It is located in Washington State. If you roll a 6, choose 1 block to read. five
Roll and Read (Green) 1 2 3 4 5 Do animals have a special sense? They might also sense changes in the air. Does this sense help them know when earthquakes and volcanoes will happen? More than two thousand years ago, a story goes, snakes and rats left a city in Greece. Just days later, an earthquake shook the city! An earthquake is a sudden movement of Earth’s crust. There is no way to know when or where an earthquake will happen. Animals may be able to feel the ground tremble before humans do. In 1975, Chinese leaders noticed that many animals were acting strangely. They told people to leave the city of Haicheng. A few days later a huge earthquake came. Did the animals guess that an earthquake was coming? There is a story that dogs once dug beneath the ground near a volcano. They did this for days before the volcano erupted. At that same time, hundreds of small earthquakes were rumbling. Maybe the dogs felt them when people could not! Volcanoes can destroy people and animals. Scientists want to know how to predict them. They study a volcano’s past. Scientists also look at how rocks inside the volcano change over time. Earthquakes and volcanoes can be very dangerous. Volcanoes have been called “nature’s fireworks.” Magma, or hot, melted rock, builds up in a volcano’s chimney. Many barnyard animals were behaving differently just before the earthquake. Dogs have been known to howl before an earthquake. Birds in cages have had trouble perching. Cats have hidden. Chickens have stopped laying eggs. If you roll a 6, choose 1 block to read. Roll and Read (Blue)
1 2 3 4 5 Predicting weather is not easy. After all nobody can really tell the future. They are built on things we have learned and on our knowledge about how things work. Monitor, means to keep a record, like a journal, of all the changes that go on around a volcano day after day, year after year. A volcano may erupt and then sit quietly for hundreds or thousands of years. When they erupt, some volcanoes create enormous amounts of noise and can damage everything around them. They have learned that before an eruption, three things usually happen. By monitoring these events, scientists hope to predict when a volcano eruption is coming. It is common for small earthquakes to occur beneath active volcanoes. Some volcanoes send out weak vibrations all the time. While scientists are working on top of a volcano, they are exposed to many dangers, including poisonous fumes and the risk of a sudden eruption. The ride to Philadelphia didn’t take long and soon we were standing outside the mint. We just answered question number one, and it only took us a few minutes! Maggie crossed her arms and smiled when I finally caught up and finished filling in the answers. Maggie and I decided right then to be partners. He, too, was the president, and helped write the Declaration of Independence. The world has about eighteen major earthquakes each year. These plates are not like the ones you eat dinner from! Instead, they contain mile after mile of solid rock. As with volcanic eruptions, scientists know a lot about where earthquakes are likely to happen. But earthquakes are not like volcanoes. They do not seem to give off warning signals. Earthquakes seem to be even more difficult to predict than volcanic eruptions. There are now volcano observations in the United States. Scientists are not able to predict the exact time and place of an eruption. Volcanologists sometimes set up a network of seismometers around a volcano. A tiltmeter is an instrument that measures tiny changes in the slant of the ground. When hot magma rises up inside a volcano, the sides of the volcano may bulge, tilt, or crack. If you roll a 6, choose 1 block to read.