Monday, April 16, 2012

Expanding our Knowledge on Earthquakes

                Most people in Virginia, prior to August, 2011, would have told you that they did not need to know very much about earthquakes because "we don't really have them here".   A lot of people in the world feel the same way.  After the 5.8 earthquake in Central Virginia, and millions and millions of dollars worth of damage here,  a lot of people were not only surprized, they were also ill prepared.    All human beings, regardless of where we live, could travel to a place where an earthquake is occurring.  Your life and the lives of your party could depend upon general knowledge of earthquakes.
                 Most of us know, and accept that many of the earthquakes in the world occur along or near the "Ring of Fire" as drawn above.   If I were to have drawn this, I would have also included Australia.

                 The fact is, that there are many more faults in the Earth than most people know about.  There are potentials for quakes in many places, and how well you would survive, largely depends on where you are and what you are doing when they occur.

                One of the things which may be helpful to you, if you are in the US, or even in Canada, is to sign up for the US Geological Surveys Real Time Feed.

       I believe this will also work if you are in other nations as well.

               Second, go to and research what types of earthquakes have occurred in your region in the past.    Then, go to your local historical society.   Find out if earthquakes or other natural disasters have occurred in your region.    It is only following evaluating your regional risk that you and your family can properly prepare for your region.   The correct preparations do indeed shift from place to place.
In California, for example, you are taught to remain in a building within the doorway area, because collapse of overhead wires above you could be fatal.  In Virginia, we are taught to exit the building and stand in the middle of the front yard, because the bulk of wires here are buried, and because the hazard of a collapsing building is thought to be greater here.  Find out what the rules and nuances are in your area.

They have not disclosed the location of this road breach. (Photo:
  It's important to make mental notes of alternate routes one could take in order to get home, or evacuate from home.   Road damage was a continued issue in Virginia following aftershocks.   Apparently, many roads are built with streams below them, and this makes them even more vulnerable to crumbling during earthquakes.  Since aftershocks are cumulative in their damage, a road which appears solid can deteriorate or collapse following an aftershock. 

       This is an interesting phenomenon which I have not yet seen.   This is a Sand Blow.  During an earthquake, the earthquake waves can push sand up through openings which are created during the quake, leaving sandy looking piles which look a but like a volcano.  Children should not play near these.  This occurred in Lepanto, Arkansas in 1964.

               It would be impossible to talk about sand boils without also touching on a phenomenon called "Liquefaction".    In February, 2011, inhabitants of Christchurch, New Zealand did not know much about liquefaction either.   Liquefaction occurs when, during a quake, soil, sand and groundwater mix, creating a rapidly moving mud everywhere.   In Christchurch, liquefaction was a major factor in building collapse and in many of the deaths which occurred.   Interestingly, aftershocks produced much higher levels of liquefaction, than did the initial quake.

A demonstration of Liquefaction in Christchurch, NZ

This instructive material is from :

                The best that we can do, is to learn whatever we can about the character and occurrances of earthquake activity in the region in which you live.   Set up your home and furniture in a manner in which injury will be less likely to occur should an earthquake occur, especially during sleeping hours.   Make plans for evacuation from your home and area.  Communicate these plans to your family members.  Gather emergency kits that not only allow your family to shelter in place, or evacuate when necessary, but consider earthquake issues specifically.    If you have high water tables where you are, then you may wish to cache your emergency supplies in multiple areas.   If all your emergency supplies are kept, for example, in a basement, and then flooding or post earthquake liquefaction ruins them, then you could be in much worse shape.  Consider metal trash cans with extra supplies in multiple locations.

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