Review the map of earthquake occurrences over a 30-day time period. The highest number of naturally occurring earthquakes can be seen along the Pacific coast, running from South America up to and along the coast of Alaska. Scientist expect the largest U. S. earthquakes to occur along the Pacific coast. Why?

Question

Responses
A It is part of the ring of fire found in the area.It is part of the ring of fire found in the area.
B It is where two tectonic plates form a deep subduction zone.It is where two tectonic plates form a deep subduction zone.
C It is divergent tectonic plate boundary, where new crust is forming.It is divergent tectonic plate boundary, where new crust is forming.
D This portion of the U. S. is very close to the San Andreas fault in California.This portion of the U. S. is very close to the San Andreas fault in California.
Question 2
Between 1973–2008, there was an average of 21 earthquakes of magnitude three and larger in the central and eastern U.S. This rate jumped to an average of 99 M3+ earthquakes per year in 2009–2013, and the rate continued to rise. In 2014, there were 659 M3 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. What is the hypothesized cause of these earthquakes?
Responses
A Drilling and digging into the crust during mining activities.Drilling and digging into the crust during mining activities.
B Injection of wastewater during increased oil recovery efforts.Injection of wastewater during increased oil recovery efforts.
C A rift zone exists in the central U.S. that has resulted in faulting.

Answer 1

Question 1: Why do scientists expect the largest U.S. earthquakes to occur along the Pacific coast?

Response: The most accurate answer is A. It is part of the ring of fire found in the area.

The Pacific coast of the U.S. is located along the Pacific Ring of Fire, which is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes due to tectonic plate movements.

Question 2: What is the hypothesized cause of increased earthquakes in the central and eastern U.S. from 2009 to 2014?

Response: The most appropriate answer is B. Injection of wastewater during increased oil recovery efforts.

Research has indicated that the increase in seismic activity in the central and eastern U.S. is largely associated with the practice of injecting wastewater from oil and gas extraction into deep underground wells, which can induce earthquakes.