Physical Geology 2003

Earthquakes in Chile

click for seismo-watchclick for seismo-watchclick for seismo-watchclick for seismo-watch

click here to go to largest earthquakes in the world webpage

Destruction after the largest earthquake of the century in Valdivia on May 22, 1960

Time line of Earthquakes in Chile

Earthquakes in Chile

Chile is located on a tectonic plate boundary and a subduction zone called the Peru-Chile trench. A subduction zone is where the ocean crust slides under the continental margin which causes compressional deformation (mountain building), earthquakes and volcanoes. Chile has experienced all of these phenomena-the Andes mountains and a long history of earthquakes and volcanoes. Earthquakes occur at any fault line, but the most destructive earthquakes happen at subduction zones. In fact, the largest earthquake of this century was in Valdivia Chile, on May 21st 1960. Siesmicity has shown us that Chile has continual earthquakes year in and year out, some much bigger than others. In the course of a year and average Chilean experiences what are called "tremors," or small earthquake shakes. Most of these small earthquakes are so small that most people can’t even notice them. The famous earthquake of Valdivia had a magnitude of 9.5 on the ricter scale, and seismicity determined that there were several earthquakes following this one all throughout Chile and into Peru. This massive quake also caused tsunamis with devastating destruction all the way to California, Australia, Hawaii, Japan and the Philippines. A tsunami is a huge wave casued by the movement of the plates under the ocean. It killed over 2,000 people and another 3,000 people injured and left 2,000,000 homeless. Valdivia was the closest to the earthquakes' epicenter, however the cities of Puerto Montt, Concepcion and several other small port towns were highly affected and shook violently. The earthquake physically distorted Chile's landscape with major landslides, violent volcanic eruptions, and other coastal deformations. For example, the rock falls and landslides in the Andes Mountains created an artificial lake on the Rio San Pedro and the Puyehue volcano violently erupted on May 24th at about 47 hours after the main shock. The outstanding destruction from the Valdivia earthquake was devastating, and although Chile hasn’t seen and earthquake with such magnitude since Valdivia, the earth continues to shake the unstable grounds of Chile.

click to go to the annaversary slide show

The violent eruption of the volcano Puyehue, which erruped two days after the earthquake, about 200km from the epicenter

SILLY GEOLOGY JOKES

Why don't mountains tell jokes? Because they might crack up!

What do you get when a cow is in an earthquake? A milkshake!

What did the earthquake say to the other earthquake? It's all your fault!

You know you drink too much coffee when a nervous twitch registers on the Richter scale and the only
time you stand still is during an earthquake!

jokes cortesy of: http://awards.schools.nsw.edu.au/entry66/facts.htm

click here to do to the annaversary addition slide show

The dock area of Angelmo in the port city of Puerto Montt before and after the Earthquake

click to see anniversary edition

The disasterous destruction of a tsunami in the town Queule , slightly north of Valdivia, the town was completely wiped out

click for annaversary edition

Tsunami destruction in the town of Ancud, which was hit with waves as high as 50 meters

 

 

Other cool sites to check out:

http://awards.schools.nsw.edu.au/entry66/facts.htm -this site has great games, jokes, earthquake experiments, fun facts and more!

www.factmonster.com/ce6/sci/A0839323.html -this site has a lot of cool facts and fun pictures

 

What is an earthquake?
An earthquake is the rapid release of energy caused by the movement of tectonic plates. When there is tectonic movement, the earth’s crust crashes and slides around resulting in vibrations in the earth. These places of movement are called faults, and the focus or center of the earthquake is located in a fault where rock ruptures or splits. There are many different types of faults and strains in the crust, and all of them send out seismic waves that make the earth shake. click for earthshaking facts

example of the movement of a fault

There are several different types of seismic waves including waves that move through the earth’s surface and ones that move through the interior of the earth. The first type of waves that hits the surface are called P waves (or primary waves), which push and pull with compression and travel though solids, liquids and gasses.

click for earthshaking facts

The P waves move like a slinky

After the P waves, come the S waves, (or secondary waves) that travel only through solids and shake the earth in a rippley motion.

click for earthshaking facts

S waves move like the movement of this rope

One of the tools that are used to measure earthquake waves are seismographs. These graphs help us calculate the size of the waves, and the location of the focus of the earthquake by using the data of three different stations to triangulate the location of the epicenter (the location on the surface directly above the earthquake’s focus).

 

click to go to the national earthquake information center

This is an example of data taken from a seismograph

Frequency of Earthquakes:

  • Everyday there are about 8,000 earthquakes
  • There are 18 major earthquakes a year
  • 2 million minor earthquakes a year
  • one earthquake a magnitude of 8 or higher a year

click to see the causes of tsunamis

The amount of travel time of the tsunami waves that were caused by the Valdivia earthquake

 

click to go to more about Chile's subduction zone

The subduction process of Chile and the active contiental margin

 

Works Cited

Coffman, Jerry and Carl Stover. "U.S. Geological Survey Professional Paper 1527", United States Government Printing Office, Washington: 1993. URL:www\earthquakes\ASC_-_Chile_Earthquakes__1960.htm

USC Tsunami research group. "The Seismic sea wave of May 22, 1960 along the Chilean Coast" URL: www.usc.edu/dept/tsunamis/index.html

Brunner, Borgna. "Earthquakes" URL: www\earthquakes\Earthquakes_.htm

The Columbia Electronic Encyclopedia Copyright 2000, Columbia University Press. "Plate Tectonics" URL: www.factmonster.com/ce6/sci/A0839323.html

Family Education Network."The Severity of an Earthquake" Columbia University Press 2002, www.infoplease.com/ipa/A0763386.html

Lavenu, Alain and Jose Cembrano. "Geological Society of America, 1997 annual meeting."Geological Society of America (GSA) : Boulder, CO, United States, 1997.

Lander, James F., and Lockridge, Patricia A., "Tsunami on West Coast of United States." U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, 1989.

NOAA National Data Centers. "Great Chile Earthquake of May 22, 1960 - Anniversary Edition." URL: www.ngdc.noaa.gov/seg/hazard/slideset/45/45_908_slide.html

Minicucci, Jenna. "Review of the Global Seismographic Network." American Geological Institute Government Affairs Program, 1997. URL: http://www.agiweb.org/legis105/gseisnet.html

Santi, Paul M. "Preliminary Evaluation of Seismic Hazards for Emergency Rescue Route." Association of Engineering Geologists, 2002. URL: http://rock.geosociety.org/pubs/eeg/0211-261.htm

Seismo-Watch, "Southern Chile M 9.5 Earthquake" URL:
www.seismo-watch.com/.../NotableEQ/ May/0522.Chile.html

Marshak, Stephen. "Earth: Portrait of a Planet" W.W. Norton & Company, New York 2001.

click for seismo-watch

Author: Iris Bieri
Creation/revision date: April 2003

[Check out the other webpages from my geology class!]

This website is part of a Geology 211 class project on Processes in Physical Geology.

Earlham · Geosciences Department · Geociences 211: Physical Geology

Copyright © 20031 Earlham College. Revised 25 February 2003. Send corrections or comments to parkero@earlham.edu