Earthquakes are among the most powerful and terrifying events on earth. Large earthquakes beneath the ocean can create a series of huge, destructive waves called tsunamis that flood coasts for many miles. Earthquakes can trigger landslides that cause great damage and loss of life. There are many thousands of earthquakes each year with as many as 20 each day. On average, a powerful earthquake occurs less than once every two years. At least 40 moderate earthquakes cause damage somewhere in the world each year. Scientists estimate that more than 8,000 minor earthquakes occur each day without causing any damage. Of those, only about 1,100 are strong enough to be felt. A severe earthquake, like the recent one in Pakistan, may release energy 10,000 times as great as that of the first atomic bomb. That is beyond our comprehension.