If you're planning to travel to South America, you should be aware of the number of earthquakes that strike across the continent each year. While some people regard earthquakes as occasional events, over one million earthquakes happen every year—though most of these are so small they remain unfelt. Still, others last for minutes that seem like hours and can cause major changes in the landscape while others are huge catastrophic events that cause massive destruction and loss of life.
Major earthquakes that happen in South America, especially on the edge of the "Ring of Fire," can result in tsunamis that crash along the Chilean and Peruvian coasts and spread across the entire Pacific Ocean to Hawaii, the Philippines, and Japan with massive waves sometimes over 100 feet high.
When massive destruction comes from natural forces within the earth, it's hard to imagine and accept the damage and destruction. Surviving one makes us wonder how we could ever survive another, and yet, there is no end to earthquakes. Experts suggest making your own earthquake preparations. There may not be an advance warning, but if you have prepared, you may come through the experience easier than others.
What Causes Earthquakes in South America
There are two major regions worldwide of earthquake—or terremoto—activity. One is the Alpide belt that slices through Europe and Asia, while the other is the circum-Pacific belt which encircles the Pacific Ocean, affecting the West coasts of North America and South America, Japan, and the Philippines and includes the Ring of Fire along the Northern edges of the Pacific.
Earthquakes along these belts occur when two tectonic plates, far under the surface of the earth, collide, spread apart, or slide past each other, which can happen very slowly, or quickly. The result of this faster activity is a sudden release of a tremendous release of energy that changes into wave movement. These waves roll through the earth’s crust, causing earth movement. As a result, mountains rise, the ground falls or opens, and buildings near this activity can collapse, bridges can snap, and people can die.
In South America, the portion of the circum-Pacific belt includes the Nazca and South American plates. About three inches of motion occurs between these plates each year. This motion is the result of three different, but interrelated occurrences. About 1.4 inches of the Nazca plate slides smoothly under South America, creating deep pressure that gives rise to volcanoes; another 1.3 inches is locked up at the plate boundary, squeezing South America, and is released every hundred years or so in great earthquakes; and about a third of an inch crumples South America permanently, building the Andes.
If the earthquake occurs near or under water, the motion causes the wave action known as a tsunami, which produces incredibly fast and dangerous waves that can tower and crash dozens of feet over shorelines.
Understanding Scale of Earthquakes
In recent years, scientists have gained a better understanding of earthquakes by studying them via satellite, but the time-honored Richter Magnitude Scale still holds true with understanding how big each of these seismic activities is.
The Richter Magnitude Scale is a number that is used to measure the size of an earthquake which assigns each quake a magnitude—or a measure on a seismograph of the strength of the seismic waves sent out from the focus.
Each number on the Richter Magnitude Scale represents an earthquake that is thirty-one times as powerful as the preceding whole number but is not used to assess damage, but Magnitude and Intensity. The scale has been revised so that there is no longer a higher limit. Recently, another scale called the Moment Magnitude Scale has been devised for more precise study of great earthquakes.
History of Major Earthquakes in South America
According to the United States Geological Survey (USGS), among the largest earthquakes since 1900, several occurred in South America with the largest, a 9.5 rating quake, devastating parts of Chile in 1960.
Another earthquake happened off the coast of Ecuador, near Esmeraldas on January 31, 1906, with a magnitude of 8.8. This earthquake produced a 5-m local tsunami that destroyed 49 houses, killed 500 people in Colombia, and was recorded at San Diego and San Francisco, and on August 17, 1906, an 8.2 quake in Chile all but destroyed Valparaiso.
Additionally, other significant quakes include:
- A May 31, 1970, earthquake in Peru with a magnitude of 7.9 killed 66,000 and caused $530,000 damage, destroying again the village of Ranrahirca.
- On July 31, 1970, an 8 magnitude earthquake struck Colombia.
- On June 9, 1994, Bolivia suffered an 8.2 quake.
- On January 25, 1999, a 6.2 quake hit Colombia.
- Coastal Peru was struck by a 7.5 quake on June 23, 2001.
- On November 15, 2004, a 7.2 earthquake struck off the west coast of Colombia, near Chocó.
- On August 15, 2007, an 8.0 earthquake struck San Vicente de Cañete, Lima, Peru.
- On September 16, 2015, an 8.3 earthquake struck off Illapel, Chile.
- On April 15, 2016, a 7.8 earthquake struck the coast of Ecuador near Muisne with destruction as far as Guayaquil.
These are not the only earthquakes recorded in South America. Those in pre-Columbian times are not in the history books, but those following Christopher Columbus' voyages are noted, beginning with the 1530 earthquake in Venezuela. For details of some of these earthquakes between 1530 and 1882, please read South American Cities Destroyed, originally published in 1906.