According to United States Geological Survey, there is a 50% chance or better of an earthquake measuring 7 or greater on the Richter scale hitting San Francisco in the next 75 years. Based on 24/7 Wall St.’s analysis of data and reports produced by the Federal Emergency Management Agency, USGS, Stanford University, insurance consultant RMS, and a number of other sources, we determined that the costs of an earthquake in San Francisco measuring the same si
ze and hitting the site of the famous 1906 disaster would reach $390 billion. That is nearly 25% of the U.S. government’s deficit for the current fiscal year.  (A repost of the report because of the Japanese 8.9 magnitude earthquake)

COMPARISON TO THE RECENT QUAKES:

It would be useful to compare of the San Francisco earthquake to those which recently occurred in Haiti, Indonesia, Chile, and Tibet. The circumstances of those events, however, are dramatically different: Three of those areas are relatively remote, and Haiti is heavily populated, but had virtually no earthquake-resistant structures. When compared to the 200,000 estimated dead in Haiti, FEMA’s projected 5,300 casualties from a large earthquake in San Francisco seems minor, but the potential infrastructure costs would be drastically higher in the bay city and the surrounding 19-county region expected to be affected by a major quake.

THE SAN FRANCISCO QUAKE OF 1906:

The epicenter of The great San Francisco earthquake of 1906 was only two miles away from the city’s center. The tremor, which is believed to have been a 7.9 on the Richter scale, almost destroyed the city.  24/7 Wall St.’s report, as well as the three we use as reference points,  come from the basic attributes of the ’06 quake as a starting point for projections about such an event’s effects on the modernized city and its surroundings.

CONSIDERED DAMAGES:

RMS estimates that the value of exposed property in the area prone to a major quake is nearly $2 trillion dollars. City planners recognize the potential disaster that may be looming, and have taken as many steps as possible to protect buildings, residences and infrastructure. While the city tries to become more earthquake-resistant, some particularly vulnerable areas remain. Among these is the wharf development along the city’s water front, which was built on landfill and older structures. Through a process known as liquefaction, in which soft ground turns to something similar to quicksand, much of the coastal area of the city would sink into the ground or collapse into the bay.

It is certain that an earthquake similar to the massive quake in ’06 would do substantial damage to the city’s four main bridges: The Golden Gate, Oakland Bay, San Mateo-Heyward, and Dumbarton bridges, as well as the thousands of smaller spans in the region. Two of the region’s three main airports – Oakland International and San Francisco international, have been built largely on land deposits, and are particularly vulnerable to liquefaction. The freshwater basin, which abuts the bay, is built with a series of levees that separate the salt water from the fresh. In all likelihood, these levees would be breached and the region would lose much of its fresh water. The main conduit for the fresh water, called the Hetch Hetchy water system, runs from Yosemite national park and crosses multiple fault lines, making its destruction nearly certain as well. Perhaps the most expensive and problematic type of infrastructure at risk of destruction is the city’s utility network, which includes the power grid, telephone lines, sewer system, and broadband connections to almost every residence and office building in the 19-county region. Other potential losses in a quake include business opportunity costs from closed offices and reduced patronage and tourism, relocation expenses, and wage losses.