It’s been called the most dangerous fault in the U.S. The Hayward Fault runs 40 miles, from San Pablo Bay to Fremont, through some of the most densely populated areas in the country. Every 140 years for the past two thousand the Hayward Fault has jolted the East Bay. Geologists have figured out the regular history of these quakes by carbon dating trenches along the fault. A lesser known cousin of the San Andreas the Hayward fault is a creeper. Basically, it moves, slowly, along the surface but deep inside… it’s locked until tension builds up and and it slips. It appears that it is time for the fault to slip again. The last major earthquake on the Hayward fault was 1868. Scientists believe that the temblor registered 7.0 in magnitude. Hayward and San Leandro were devastated. But if the quake were to happen today, it would be a much different story.

I met Mary Lou Zoback out at the Fremont Bart station, which sits right on top of the Hayward Fault. She pointed out cracks in the parking lot from the creeping fault. Zoback is a geophysicist who worked 28 years at the U.S. Geological Survey and who has done catastrophe modeling of risky residential buildings. Her company estimates that a 6.8 quake, or bigger, on the Hayward Fault could cause a disaster on par with Hurricane Katrina, causing 168 billion dollars in damage and leaving at least 200,000 homeless.

A number of public buildings in the east bay are undergoing retrofitting to make them more structurally sound. Area hospitals have until 2013 to meet seismic safety standards. There is a state inventory of public schools prone to collapse in a major quake, but no such list exists for private schools. And retrofitting standards for risky residences are confusing. I talked with Jim Cook, of Bay Area Retrofit. He says existing codes are unclear and there really is no specific licensing for seismic home retrofitters. Cook has been fighting local governments for years to improve seismic safety standards.

Homeowners can have their home evaluated but what if you are a renter? Many apartments and condos can collapse in earthquakes because they have parking or open commercial space on the first floor making this story weak or “soft.” According to the Association of Bay Area Governments Earthquake and Hazards Program, soft-story apartment buildings were responsible for about two-thirds of the 46,000 uninhabitable housing units in the 1991 Northridge earthquake. In the Bay Area, unreinforced masonry (older buildings constructed of brick, stone or cement blocks) continues to be a threat.

The thought of a big earthquake is scary enough, never mind the chaos that can happen in the aftermath. But the damage from a large earthquake has repercussions that can last for a very long time. We can still see the scars from the 1989 Loma Prieta earthquake. Downtown Santa Cruz is not yet fully rebuilt and retrofitting continues on the Bay Bridge. We can prevent a lot of damage up front by shoring up our buildings and creating a family disaster plan and an earthquake kit. The Hayward Earthquake Alliance has put together some really helpful information on how to prepare for a major quake.

Listen to the Hayward Fault Radio Report and view the recent QUEST TV segment on the fault online.

I’m not a gambling man but I suppose living in the Bay Area is a gamble in and of itself, given that the likelihood of an earthquake here of magnitude 6.7 or greater in the next 30 years is 67 percent. As our QUEST TV segment on the Hayward Fault, produced by Amy Miller, and an upcoming QUEST radio segment produced by Andrea Kissack attest, the greatest seismic risk posed to Bay Area residents is the Hayward fault, which last ruptured 150 years ago. The fact that the fault ruptures on average every 140 years, offers a sober reminder of the seismic risk that people working and residing in the East Bay face every day, including Amy and Andrea, as well as several other QUEST colleagues who reside in Berkeley and Oakland. As Mary Lou Zoback stated during the interview, a major earthquake along the Hayward fault would be economically much more catastrophic than Hurricane Katrina, coupled with the difficulty of coordinating relief services in communities like Fremont, where more than 100 languages are spoken.

So we know – or should know – the seismic risks of living in one of the most vibrant, diverse places in the U.S. Short of leaving the region, what can we do?

Well, one of the most illuminating things about working on this story for me was learning a bit about retrofitting one’s home to make it withstand the lateral and vertical forces that accompany a strong earthquake. In short, you need to build shear walls – made of reinforced plywood and shear transfer ties – and bolt them to the walls in the foundation of your house. Suprisingly, there are no official codes as to what constitutes a proper seismic retrofit of a residential unit in California, nor is there a dearth of licensed contractors who will offer quotes and purport to retrofit your home but without any standards in place, homeowners are often at a loss to evaluate the quality of the retrofit which can easily exceed ten thousand dollars, depending on the size of the home and its location. Still, homeowners can avail themselves of a few retrofit resources online, such as Plan Set A, a guideline for retrofitting one’s home that has been approved by building departments of several Bay Area municipalities such as Oakland and Hayward. Also on the Association of Bay Area Government’s web site is a set of schematics illustrating shear wall construction. If you are interested in retrofitting your home, you should get quotes from several contractors, consult your city’s building department to inquire about permits and possibly consult a structural engineer to perform a building analysis on your home.

If you’re like me, though, and don’t own a home but want to prepare for “the big one,” it’s imperative to get an earthquake survival kit. The sells earthquake survival kits but why not make your own, provided that it has water, first aid supplies, a flashlight, food rations and other essentials for you to survive 72 hours while waiting for emergency help. If you want to make your own kit, try the USGS, the city and county of San Francisco, or helpful suggestions from the San Francisco Chronicle and LA Times.

Living in earthquake country, it pays to be vigilant. I applaud the 1868 Hayward Earthquake Alliance, a consortium of agencies that are raising awareness of the risk posed by the Hayward fault with a series of events aimed at educating the public about the importance of preparedness, including a city-wide drill in San Francisco on October 21st, the 140th anniversary of the 1868 Hayward earthquake. We may not be able to predict when exactly the next earthquake on the Hayward fault may occur but we can start planning today to mitigate its effects.

For those who aren’t familiar with the Hayward fault, check out our this link to the USGS Google Earth tour over the fault.

I had the privilege this week of interviewing Isabel Hawkins, an astronomer and director of the Center for Science Education at Berkeley’s Space Sciences Laboratory. We talked about how people use evidence in science, how it is that we know what we know.

Hawkins isn’t your ordinary astronomer. She began her career in an ordinary way: Ph. D. in Astronomy from UCLA, using mathematical models and computer simulations to give meaning to her observations. Along the way, she began to learn about how ancient people studied the sky. She’s worked with us on our Ancient Observatories website, and hosted an equinox webcast from the top of the Mayan pyramid in the ancient astronomical site of Chichen Itza. And she’s devoted a considerable amount of time and energy to understanding and appreciating how the knowledge of ancient people complements what modern scientists study today.

Most scientists today don’t learn much about ancient knowledge. Observations such as measurements of the sun’s movement across glyph-crusted temples don’t usually meet the rigorous criteria of the scientific process: observe, create hypothesis, test, reproduce results.

In some instances, ancient people followed similar practices that were very similar to those used by modern scientists, observing things systematically and trying to devise explanations that will result in correct predictions. And sometimes the knowledge they gathered was, in fact, so “scientific” that modern researchers use it in their work today.

Take, for example, the knowledge of the Aymara Indians in Peru. The well-being of these adept weather-watchers was dependent on knowing how to time the planting of their vital potato crop with the arrival of the season’s first rains sometime between October and December. They did this by making observations like meteorologists might today. They watched the Pleiades, or Seven Sisters constellation rise each night, and noted how fuzzy or clear it looked in the sky. Fuzziness caused by cirrus clouds high in the sky, meant rains were a ways off, and potato planting should be postponed. A clearly visible set of Sisters meant rains would come soon.

In 2002, Ben Orlove an environmental scientist at UC Davis, published a paper about the accuracy of the Aymara’s observations of the Pleiades. It turned out that these ancient observations could be used by modern scientists to discern El Nino patterns in the past. Fascinating, since these measurements were taken long before there was a formal science of meteorology. Ancient knowledge becomes data points in modern research.

Hawkins cited another example: Ruth Ludwin, a seismologist at the University of Washington, has used generations-old folk tales of the Coast Salish Indians to help inform her computer modeling of earthquakes. The tales recount a serpent that knew where and when an earthquake would strike. By adapting location information from the stories into her computer models, Ludwin has found several small faults in the Seattle area that may have been active hundreds of years ago when the stories were created and may still pose a risk to local communities.

“It’s interesting that what we call evidence can come in many forms,” Hawkins says. “It might be part of a song, or a glyph writing or an artistic piece or a story.”

And sometimes the records we keep and the stories we tell have more meaning than we can imagine when we create them.

Robin Marks is a journalist and science writer who current serves as a Multimedia Projects Developer for the Exploratorium in San Francisco, CA.