The Pacific Ring of Fire Michael Mosca

Geology 103Professor Mark Lawler

The Pacific Ring of Fire is a horseshoe shaped

area that surrounds the Pacific Ocean and

produces great seismic and volcanic activity. It

rings four continents and its effects have impacted billions of people and the

world economy for centuries.

(Cain and United States Geologic Service 1999,

1997)

The reason for all the activity on the Ring of Fire is plate tectonics. The earths outermost layer the “Lithosphere” or crust is divided into 7 large pieces or plates. These plates are always moving. When they crash into

each other its called a “Convergent Boundary”. When they pull apart its called a “Divergent Boundary”. When they sideswipe each other its called a “Transform Boundary”. The majority of the activity on the ring of fire is the convergent boundary of the Pacific Plate and the North American

Plate. (Wheeling Jesuit and NASA 2004)

This slide shows the plate puzzle. In South America the Nazca Plate is moving underneath or “subducting” the South American Plate in a convergent boundary. In the Pacific Northwest the Juan de Fuca Plate is sinking under the North American Plate. In the Aleutians the Pacific Plate is moving beneath the North American Plate. In the Western Pacific the Pacific Plate is moving under the Eurasian Plate, this is responsible for the Japanese Islands and their problems. (PBS 1998)

In June of 1991 Mt. Pinatubo erupted. This

volcano is in close proximity to the Philippine capital of Manila. Over 1000 people

were killed and over 100,000 were made homeless. Millions of tons of a

poisonous gas called Sulfur Dioxide were released into the atmosphere. Because of this release the atmospheric temperature of the planet

decreased.(Rosenburg) What caused this eruption

was activity on the Australian and Pacific

Plates. This is a Divergent Boundary (pulling apart)

which caused the subduction or sinking of the Manila Trench on the seafloor.

The slide on the left shows an aerial photograph of the San Andreas Fault. The slide on the right is a map of California showing how this

“Transform “ boundary is moving the landscape. The San Andreas is probably the most well known fault-line in the world. The San Francisco earthquake of 1906 killed about 700 people and about burned the city to the ground. The sliding forces on this transform boundary will place the city of Los Angeles right next to San Francisco in about 10 million years.

There are over 900 volcanoes in the Andes Mountains of South America, many near large population areas. One of the challenges of today’s scientists is trying to predict when and where these volcanic seismic events will take place. Scientists from Cal Tech are now using “radar

interferometry” data to determine the volcanic behavior in the region by monitoring ground movement from space. (Tindol 2002)

In early March 2011 a series of large quakes rocked Japan. These quakes produced Tsunamis or tidal waves that completely wiped out villages and caused meltdowns at two coastal nuclear facilities. Tens of thousands of people perished and the estimated cost of this disaster will run into the

billions. (National Geographic 2011)

The death toll from the Japan quakes would have been much higher if not for the Pacific Tsunami Warning Center. This warning center was developed in the Hawaiian Islands for the Pacific Basin in 1968. The

program now extends into the Indian Ocean after the devastating 2004 tsunamis. (NOAA 2009)

80% of all earthquake activity occurs on the “Pacific Ring of Fire”. Over 10,000 people die every year from the

destruction and the cost is in the billions. If countries inform their citizens on disaster preparedness and insure building construction is adequate most loss of life can be avoided.

(National Geographic 2010)

References

"Hot Spots" and the Ring of Fire. United States Geological Service. Retrieved July 19, 2011, from http://volcan.wr.usgs.gov/Glossary/PlateTectonics/Maps/map_plate_tectonics_world.html

Cain, F. (1999). Pacific Ring of Fire. Universe Today. Retrieved July 19, 2011, from www.universitytoday.com (59341).

Rosenburg, M. (n.d.). Mt. Pinatubo. In About.com. Retrieved July 19, 2011, from http://geography.about.com/od/globalproblemsandissues/a/pinatubo.htm

PBS. (1998). Savage Earth. In . (Ed.). Arlington, VA: Educational Broadcasting Corp. Retrieved July 19, 2011, from http://www.pbs.org/wnet/savageearth/hellscrust/html/sidebar3.html.

NASA. (2004). Earth Floor. In . (Ed.). Wheeling, WV: Wheeling Jesuit University. Retrieved July 20, 2011, from http://www.cotf.edu/ete/modules/msese/earthsysflr/plates4.html

National Geographic. (2002). Radio Inferometry. Pasadena, CA: Robert Tindol. Retrieved July 20, 2011, from http://news.nationalgeographic.com/news/2002/07/0710_020710_volcano.html

Natural Disasters (2010). In National Geographic.com. Retrieved July 20, 2011, from http://environment.nationalgeographic.com/environment/natural-disasters/earthquake-profile

Pacific Tsunami Warning Center. (2009). In National Geographic.com. Retrieved July 20, 2011, from http://ptwc.weather.gov/ptwc/history.phpusdeptofcommerce/NOAA/NWS

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