Grade 4 Reading Information - Information Integration

Story 1 - Volcanoes

Volcanoes erupt from the shifting of tectonic plates. One plate shifts and moves underneath another plate. When this happens, an earthquake, tsunami or other disaster may take place. Then water seeps into the plates. The rock surrounding the plates will melt at cooler temperatures. Then it comes into contact with other rock. Pressure forms as the rock or magma moves up to the surface and breaks through.

Another way that a volcano erupts is through rifting. This way begins with the crust flattening out. When the crust is flattening out, the pressure lowers. Again, similar to the first way, the rock melts at a cooler temperature. Then the magma of rock moves up through the volcanic mountain until it erupts.

There is one way that a volcano erupts without having lower temperatures and lower pressure. There are certain times when the rock underneath the surface gets very hot. In this case, it builds pressure and forces the hot magma through the volcanic mountain. These are known as hot spots.

Story 2 - Volcanoes

The majority of volcanoes are found in an area surrounding the Pacific Ocean. It is called the Pacific Ring of Fire. The tectonic plates and their location play a part in where volcanoes are and their eruptions.

Hawaii is known for having a large number of volcanoes. There are actually five active volcanoes in Hawaii which means they could erupt at any time. Volcanoes can erupt in one large lava flow or they can slightly spew out lava. The volcano Kilauea is still erupting after 25 years.

Probably the most famous volcanic eruption was in 1980 when Mount St. Helens erupted. This volcano is located in the state of Washington. The large volcanic eruption triggered many smaller earthquakes in the surrounding areas. Over 50 people died from the eruption and millions of dollars in damage was caused by this eruption.