Tag Archives: San Andreas fault

Earthquakes in Oaxaca? Yes

As a Californian, I grew up respectful of the power of earthquakes and in fear of the devastation they could cause.  The 1988 Loma Prieta earthquake, centered in Santa Cruz, California, was in my sister’s backyard.  Anything breakable was destroyed and buildings constructed before “code” or ignoring the boundaries of legal approval were vulnerable, toppled or structurally compromised.  I remember the “shake, rattle and roll” years of living in San Francisco and the dread of driving into an underground parking garage, wondering if this would be the unpredictable moment that all would fall down.  Now, four days after the Haiti earthquake, we take stock of where we live, how we live, how we build our dwellings and public spaces, and the impact of poverty on physical safety.

The state of Oaxaca is on the San Andreas fault line, which runs from the west coast of the U.S. down the spine of the Sierra Madre mountain range into southern Mexico.  The historic city of Puebla was victim of a massive quake in the last two decades, and the areas around the volcanoes that border Puebla, Guerrero and Oaxaca are particularly volatile.   There are no skyscrapers here.  Oaxaca is the second or third poorest state in Mexico and there are shantytowns in every corner of this magnificent city and scattered throughout the countryside in the poorest villages.

Those who have money to build solid adobe or brick construction understand that they must dig deep to anchor their foundations.    Foundation trenches are at least four to six feet deep and two to three feet wide, filled with huge boulders, steel girders and then concrete.  I have to believe that this type of construction has evolved over hundreds of years of experience.  Adobe will crumble; bricks and concrete block will topple.  And, the huge fortress churches of these Mexican cities (including Puebla and Oaxaca) have survived over 500 years of earthquakes reaching magnitudes of seven on the Richter scale.

There was a day last summer when I was awakening in the early morning from a deep sleep and felt a gentle shake and rattle.  Ah, I said, must be an earthquake.  We are used to them in Oaxaca and believe it is a good sign that the earth is giving off it’s geological stress to relieve the pressure.  Hopefully, this periodic burp will avoid the “big one.”  Was the earthquake in Haiti different because there hadn’t been a major quake there (7+) in over 200 years?  Are little quakes a reminder that we live in a region that is at risk and we need to take precautions?  How much precaution CAN be taken when there is not enough money to build a proper home to withstand the forces of nature?  Supposedly, the human tragedy of a natural disaster does not discriminate based on wealth or poverty.  Yet, we know that the poor suffered most in New Orleans.  Will the same be true in Haiti?  Can human beings win against the forces of nature?  Not likely.

As for Oaxaca, people with money will dig their foundations deep while the poor construct shelter out of tin scraps, cardboard and discarded bed springs.