LOS ANGELES (CBSLA.com) — A leading earthquake expert has issued a dire warning to Californians about the expected impact of a major disruption to the San Andreas fault line.

The title of Dr. Lucy Jones’ lecture this week to the American Geophysical Union in San Francisco was titled “Imagine America without Los Angeles.”

As KCAL9’s Dave Bryan reports, Jones, a Science Advisor for Risk Reduction at the U.S. Geological Survey, says when the “Big One” hits Southern California, the damage could be much greater, and could last much longer, than most of us ever imagined.

“Loss of shelter, loss of schools, loss of jobs and emotional hardship. We are risking the ends of our cities,” she said during the presentation.

According to a USGS study called the “Shakeout Report,” when a high-magnitude earthquake rocks the San Andreas fault, the damage will go far beyond the collapsed buildings and freeways seen in the 1994 Northridge earthquake.

For example, LA-area supermarkets now depend on Internet systems for warehousing and shipping food to stores, and the food is stored on the other side of the San Andreas fault.

“With the development of the Internet and the new just-in-time economy, none of them store food on the Los Angeles side of the San Andreas anymore,” Jones said.

“So this is one more place where the development of the complexity of our modern society is creating new vulnerabilities as we face the big earthquakes.”

Fiber-optics could also be cut off when a disastrous earthquake hits the San Andreas fault.

“Two-thirds of the connectivity from Los Angeles to the rest of the world go through fiber-optic cables crossing the San Andreas fault,” Jones explained. “So we expect at the time of the earthquake when the fault moves, we will break these fiber-optic cables and two-thirds of the data capacity between LA and everyone else will disappear,” she said.

Natural gas pipelines also cross the San Andreas fault, so gas for cooking and heating would be in short supply.

And the area’s aging water pipes, which seem to break with great regularity even without a temblor, are not expected to stand up well when the big earthquake hits.

“The water pipes — remember the first thing you put in in a city is the water pipes. That means our water pipes are some of the oldest parts of our infrastructure,” Jones said.

“Seventy percent of the water pipes in Southern California are AC pipes and many of them will be breaking when this earthquake happens.”

Much of the high-tech damage could hinder the recovery effort in the weeks and months after the earthquake, according to Dr. Jones, so getting Southern California back on its feet could be a wrenching process.

“The World Wide Web wasn’t in existence at the time of the Northridge earthquake,” she said. “Right now think of how much both your personal life, but also our economic system, depends on having cell phone communications and internet connectivity (sic).”

The “Shakeout Report” from the USGS estimates it could take six months for the broken water pipes to be replaced across Southern California after the earthquake.

And they say while the Northridge quake directly affected about a half a million people, a maximum credible earthquake on the San Andreas fault could affect 10 million Californians.