Ever since the media hyped-up the increased seismic activity, the fear of an earthquake still lingers, which brings up the question of what LCHS should do in the case of an emergency.
Aside from the ‘Big One,’ an earthquake with a 7.0 magnitude or greater that is supposed to occur on the San Andreas Fault, there are also concerns with another fault line that is much closer to us. The Sierra Madre Fault, which runs right through JPL and the Paradise Canyon neighborhood, is more dangerous to us if a moderate-to-severe earthquake occurs there.
Mr. Traeger, who teaches geology among other sciences, stated that, “It isn’t the fault that is the biggest that is going to get you. It is the one that is the closest.”
A shock from the Sierra Madre Fault could potentially create a similar outcome to that of the 1994 Northridge Earthquake, in which buildings collapsed and billions in property damage occurred; fifty-seven deaths occurred along with 8,700 injuries. However, that earthquake had a 6.7 magnitude, so the impending one could be more calamitous. It also occurred on a federal holiday (Martin Luther King Jr. Day) during the early morning, which resulted in less casualties due to the collapse of only a few commercial buildings.
Although an earthquake on the Sierra Madre Fault could cause catastrophic damage, the threat of a ‘Big One’ from the San Andreas Fault is still substantially dangerous, as it is more or less 50 miles away from us.
As for the direct effects of an earthquake, Mr. Traeger explained, “If you look upon a map, the school is built upon unconsolidated sediment. Basically, that’s floodplain deposit from the Arroyo Seco. When the earthquake waves pass through this material, it will be amplified. So the energy and size of the wave will become bigger. So we will sustain some more shaking due to the ground type.”
The soundness of the building is another factor for our school in the event of an earthquake.
“I was told by Dr. Leininger, a past facilities manager and superintendent, that at some point, the A and B buildings were retrofitted. However, I can tell you that both of these buildings along with the North Gym and also, I believe, the South Gym were all built in 1963,” stated Mr. Traeger.
The significance of this date is that it was before the Alquist Priolo Laws, which were passed in 1972. These laws changed building codes to create greater safety in preparation of an earthquake and restricted buildings from being built within a certain distance of a known fault. The school’s original buildings, therefore, could be at risk during a devastating earthquake. Even though the A and B buildings were reportedly retrofitted, it could still be insufficient. Therefore, the status for those buildings is unknown.
“We all know what the drills are, but how that goes down in a real earthquake is yet to be seen,” said Mr. Traeger. “Any time after a major earthquake, you are going to have aftershocks that could weaken the building, which can be potentially devastating. To say that what is going to happen after that in terms of our evacuation is going to be another story. We don’t know what stairwells or bridges that will be compromised. There are too many unknowns as to how this building is going to fare in a magnitude of 7.0 or greater.”
Although we had the Great Shakeout recently, continuous preparation for earthquakes is necessary.