Ring of Fire
Use the information below to complete the handout.
The area encircling the Pacific Ocean is called the "Ring of Fire," because its edges mark a circle of high volcanic and seismic activity (earthquakes). Most of the active volcanoes on Earth are located on this circumference.
Pacific Northwest Seismic Data
This is a map of seismic activity of the Pacific Northwest
Each yellow (35-70 km deep) and orange (less than 35 km deep) dot represents an earthquake
What pattern do you see?
What does this pattern mean?
Map generated using the U.S. Geological Survey. “Earthquake Hazards Program :Earthquake Center”
Southeast Asia Seismic Data
This is a map of seismic activity of Southeast Asia
Each yellow (35-70 km deep) and orange (less than 35 km deep) dot represents an earthquake
What pattern do you see?
What does this pattern mean?
Helpful Information: Looking at Japan, there is a much different picture than Washington. Japan is located at the junction between 4 different plates. The North American plate extends from the Aleutian Islands around to the Kamchatka Peninsula on the northern boundary of Japan. To the east is the Eurasian Plate, to the west the Pacific Plate and then to the south the Philippine Plate. Each of these plates is moving in a different direction and Japan is caught in the middle. As a result, your students should notice that there are far more earthquakes (dots) in this area than in the Pacific Northwest.
Pacific Rim Seismic Data
This is a map of seismic activity of the Pacific Rim
Each yellow (35-70 km deep) and orange (less than 35 km deep) dot represents an earthquake
Do you see any patterns?
What do these patterns tell you?
Helpful Information: Notice that in some areas the earthquakes (especially the deeper yellow earthquakes) form “lines”. These lines are plate boundaries. Shallow earthquakes can be the result of other processes such as explosions, landslides, and nuclear testing just to name a few. That is why there is not as clear of a pattern in the orange dots as the yellow.
