Posts Tagged ‘San Andreas Fault’

The San Francisco earthquake needs no real introduction.  And that’s true despite the fact that the city surrounding San Francisco Bay is bumped and jostled by a good many quakes each year.  Most of them are rather mild and I suppose some that can be detected by seismic equipment aren’t even felt by the public.

But many can be felt, even if only a little.  Living in the Midwest, I’ve never experienced an earthquake, so I have no idea what one feels like.  I imagine there’s a low rumble and then some wiggling around for a few seconds.  Maybe one feels a bit woozy and disoriented, sort of like air- or sea-sickness, but again, I’m just guessing.  Californians have a far greater depth of experience than I.

Like I said, most quakes are fairly small, but there have been some biggies.  There was a powerful quake that struck in 1989 as the World Series was getting underway…we’ve talked about that one.  But when someone mentions The San Francisco Earthquake, just one is being referenced.

The earthquake that struck on April 18, 1906.

Residents of the city were jolted awake shortly after 5:00am by a powerful shock that measured 7.9 on the Richter Scale, as the San Andreas Fault (which runs just west of the city and bay) ruptured along 300 of its 800 miles.  I’m not an expert, but from what I’ve read, the San Andreas Fault is where two of the earth’s plates meet.  The western plate tends to edge north while the eastern place moves south.  Over time, stresses build up as the plates grind against each other.  Then the pressure releases in a quake.  Most are small, but this particular one was not.

It toppled buildings and homes on a grand scale, causing tremendous damage.  But just as devastating was the resultant fire which, combined with the quake, destroyed upwards of 80% of the city.  Most of the pictures of the quake’s aftermath show destruction on par with cities that were heavily bombed during the Second World War.  More than 3,000 lives were lost and more than half the city’s population was left homeles, making it California’s worst natural disaster, and one of the worst disasters in U.S. history.

Today, structures on the West Coast are built with the various fault lines in mind.  Much like Japan, everything is done with “an eye toward the ground.”  In every sense, San Francisco is far more prepared to deal with earthquakes than, say, St. Louis, which also sits in relative proximity to a fault.  But as I said before, the San Andreas still lurks…

Read Full Post »

Let’s see…what would I have been doing at about 7pm on October 17, 1989?  If memory serves me right (and it doesn’t), I was probably sitting at home relaxing after yet another day of exposure to college life.  Baseball’s World Series was going on at the time, but since it was Oakland and San Francisco and not the Atlanta Braves (who had endured another horrible season), I wasn’t really interested.

At the same time in San Francisco, people may have been heading home early or driving to Candlestick Park for the big game.  Many would have been working in their offices or taking an afternoon nap.  Regardless, the lives of Bay-area residents were about to be turned upside down…in the most literal sense.

Just a couple minutes past 5pm, a monster earthquake, measuring 6.9 on the Richter Scale, struck the Bay area, caused by a large slip along the infamous San Andreas Fault.  According to experts, the earthquake only lasted about 15 seconds or so, but the energy released in the slippage was equivalent to exploding (and this is hard to fathom) nearly 54 billion pounds of TNT.  That’s more than 1,000 times larger than the atomic bomb that was dropped on Nagasaki.  That’s a lot of power and, needless to say, the results were catastrophic.

While damage was concentrated in San Francisco, it certainly wasn’t limited to just that area, as heavy damage was reported in locations nearly 60 miles from the epicenter.  The quake was felt as far east as Reno, NV and as far south as Ventura, CA.  Thousands and thousands of buildings and homes collapsed, numerous sections of the Interstates split apart, as did hundred of highways and city streets.  Many bridges were heavily damaged, with some collapsing altogether.  Ruptured gas lines caused numerous fires.  Total damage would run into the billions of dollars.  Even the Goodyear Blimp, flying above Candlestick Park, was bounced around by the quake.

Sixty-three people lost their lives as a result of that 15 seconds in October, two-thirds of them on the collapsed Cypress Street Viaduct in Oakland.  More than 3,700 people were injured, and hundreds of thousands of lives were changed forever, as upheaval, uncertainty, and helplessness became the order of the days and months ahead.

Almost 20 years later, the homes have been rebuilt, buidings have been reconstructued, and the roads and bridges are servicing traffic again.  But the San Andreas still lurks…

Recommended Reading: The Loma Pietra Earthquake – The U.S. Geological Survey site.

Read Full Post »