California recently rolled out its early warning system.
And now, new funding from the federal government will help expand or strengthen the system around Lake Tahoe, Death Valley, Mammoth and Bishop, where the potential for major earthquakes has been found.
This is great news. The early warning system operates on a network of underground sensors that detects seismic activity and sends out warnings that allow people time to duck and cover. Elevators can be stopped on the nearest floor, subways and rail transit can come to a halt, surgeons in hospitals will know to wait before making an incision.
But unfortunately, this system does nothing to protect buildings and infrastructure from damage from a quake. Only seismic retrofits done before the earthquake strikes can protect these structures.
Why is Protecting Buildings Important?
Los Angeles County ranks as No. 1 region for earthquake damage and loss, according to the United States Geological Survey. A recent study at U.C. Berkeley performed by the California Geological Survey supported that finding, ranking potential damage in Southern California higher than that of any other part of the state, including San Francisco.
The California Geological Survey found that in Southern California, a magnitude 7.1 quake along the Puente Hills fault would bring an estimated $69 billion in damages. Other calculations for Southern California include $49 billion from a 6.9 magnitude quake on the Newport-Inglewood fault; $30 billion from a 7.1 magnitude event along the Palos Verdes fault; $29 billion from a 6.8 event on the Whittier fault; and $24 billion for a 6.7 event on the Verdugo fault.
These figures represent more than just widespread loss. Every dollar reflects damage to the building or structure – in many cases putting severe hardship on the building owner and its occupants.
The USGS determined that 300,000 structures would be damaged in a 7.8 San Andreas earthquake. That’s one in every 16 buildings in the region. The types of structures determined to be most vulnerable in a quake include: unreinforced masonry built before 1975, non-ductile concrete built before 1977, soft-story structures built before 1978, concrete tilt-up structures built before 1994, and steel moment frame structures built before 1996.
Studies Show Cost Benefits of Retrofits
Researchers at Caltech have determined that for every dollar spent in retrofitting soft-story structures, property owners could expect to save up to seven dollars in quake damage, and that study didn’t factor in loss to contents, alternate living expenses or deaths and injuries – all of which would have significantly increased the cost-to-benefit ratios.
In a separate study, the university determined that seismic retrofits are cost-effective when projected annualized loss would be reduced by 50 percent or more at a cost that would equal no more than 10 percent of the replacement cost of a building.
There are other strong economic factors to consider when weighing the cost benefits of a seismic retrofit. These include potential loss of income and liability associated with damage, death and injury associated with an earthquake.
Loss of income can occur when commercial property is damaged to the point where it is no longer habitable. This can create severe financial hardship for property owners who not only lose their monthly rental income, but simultaneously face the costs of recovery coupled with ongoing monthly payments associated with their original mortgage.
There are liability risks as well. A precedent-setting case in Paso Robles found building owners negligent and liable for the deaths of two workers killed in an earthquake in 2003. A state appeals court upheld the verdict in 2010 setting the precedent that it doesn’t matter if a quake is an “act of God” or that the building in question technically complies with city building codes. Just knowing a structure is unsafe and not taking action is grounds enough to assign blame through negligence, the courts found.