Question
Select the best evidence to support the statement "There has been a large increase in the number of earthquakes since the 1970s."
Within the central and eastern United States, the number of earthquakes has changed dramatically over the past few years. Between the years 1973-2008, there was an average of twenty-one earthquakes of magnitude three and larger in the central and eastern United States. This rate jumped to an average of ninety-nine magnitude three or larger earthquakes per year in 2009-2013, and the rate continues to rise. In 2014, alone, there were 659 magnitude three and larger earthquakes. Most of these earthquakes are in the magnitude 3-4 range, large enough to have been felt by many people, yet small enough to rarely cause damage.
The change in the number of earthquakes prompts two important questions: first, are the earthquakes natural or manmade? Second, what should be done in the future as we address the causes and consequences of these events to reduce associated risks?
Within the central and eastern United States, the number of earthquakes has changed dramatically over the past few years. Between the years 1973-2008, there was an average of twenty-one earthquakes of magnitude three and larger in the central and eastern United States. This rate jumped to an average of ninety-nine magnitude three or larger earthquakes per year in 2009-2013, and the rate continues to rise. In 2014, alone, there were 659 magnitude three and larger earthquakes. Most of these earthquakes are in the magnitude 3-4 range, large enough to have been felt by many people, yet small enough to rarely cause damage.
The change in the number of earthquakes prompts two important questions: first, are the earthquakes natural or manmade? Second, what should be done in the future as we address the causes and consequences of these events to reduce associated risks?
Answers
GPT-4o mini
The best evidence to support the statement "There has been a large increase in the number of earthquakes since the 1970s" is the specific data cited regarding the average number of magnitude 3 and larger earthquakes in the central and eastern United States. Specifically, the evidence shows that:
- From 1973-2008, there was an average of 21 earthquakes of magnitude 3 and larger per year.
- From 2009-2013, that average increased to 99 earthquakes of magnitude 3 or larger per year.
- In 2014 alone, there were 659 magnitude 3 and larger earthquakes.
This clear numerical increase from an average of 21 to 99, and then a significant spike to 659, illustrates a substantial rise in earthquake activity, supporting the claim of a large increase since the 1970s.
- From 1973-2008, there was an average of 21 earthquakes of magnitude 3 and larger per year.
- From 2009-2013, that average increased to 99 earthquakes of magnitude 3 or larger per year.
- In 2014 alone, there were 659 magnitude 3 and larger earthquakes.
This clear numerical increase from an average of 21 to 99, and then a significant spike to 659, illustrates a substantial rise in earthquake activity, supporting the claim of a large increase since the 1970s.