A. Answer the questions by choosing the most appropriate alternative from those given below.
1.In a fissure eruption of a volcano, the lava comes out
a.from the base of the volcano
b. from the sides of the volcano
c.from a crack or fissure in the volcano
d. from all around the volcano
a.
Answers
Answer:
Chapter 2 Earthquakes and Volcanoes
Chapter 2 focuses on Earthquakes and Volcanoes.
Lessons included in this chapter:
#4 Earthquakes - The Rolling Earth
#5 Volcanoes
#6 Volcanic Terms
Resources for Teachers can be found under the Chapter #2 Copymaster.
Select from the options on the right to proceed.
Earthquakes - The Rolling Earth Lesson #4
rollingearth1
An earthquake is a sudden, rapid shaking of the Earth caused by the release of energy stored in rocks. This energy can be built up and stored for many years and then released in seconds or minutes. Many earthquakes are so small that they can not be felt by humans. Some, on the other hand, have caused great destruction and have killed hundreds of thousands of people. The pink lines and dots on the map of the world above indicate the regions of earthquake activity.
There are two major regions of earthquake activity. One is the circum-Pacific belt which encircles the Pacific Ocean, and the other is the Alpide belt which slices through Europe and Asia. The circum-Pacific belt includes the West coasts of North America and South America, Japan, and the Phillipines.
Over one million earthquakes may occur each year on the Earth. Most earthquakes last only seconds, but some large quakes may last minutes. About 90% of all Earthquakes are produced at plate boundaries where two plates are colliding, spreading apart, or sliding past each other. When these plates move suddenly they release an incredible amount of energy that is changed into wave movement. Earthquake waves resemble sound and water waves in the manor in which they move. It is these waves that roll through the Earth's crust causing buildings to collapse, bridges to snap, mountains to rise, the ground to fall, and in some cases the ground to open up into huge cracks.