He covers news, politics, science, sports, outdoors and Bay Area history. Fort Mason is an exception. The houses on the hillside have more protection. The area was a fill area along the former course of Mission Creek. (Shown: The San Francisco skyline across the bay from the decommissioned Alameda Naval Air Station. Developers of properties falling within … On the other end of the spectrum is "Soil Type E" — which includes water-saturated mud and artificial fill. In some cases, the quakes were only about 90 years apart.Reporter Mike Moffitt has been writing and editing stories for newspapers and news websites for more than 25 years. "The most recent scientific study indicates that for the entire San Francisco Bay Area there is about a 70% chance of a magnitude 6.7 or greater in the next 30 years occurring on one of the several earthquake faults that run through the area," geophysicist Brocher said the most likely suspect for the next big quake is the Hayward Fault Zone, a 74-mile-long fault line in the East Bay that hasn't produced a massive shaker since 1868.The U.S. Geological Survey has identified five kinds of soil types in the Bay Area that affect the shaking a building might receive in the event of an earthquake.If you're fortunate, your home is perched on bedrock, which does not contribute greatly to shaking amplification. Eyewitnesses estimated that 150 to 300 people died inside the Brunswick Hotel alone after it collapsed and burned. The high-intensity shaking in the neighborhood was exceeded only by areas in close proximity to the San Andreas Fault. )Foster City, built on an engineered landfill, was one of the early developments of San Francisco Bay. The epicenter was 60 miles south of the Marina, yet the quake still severely damaged or collapsed 70 buildings in the neighborhood.Ironically, much of the Marina's sand, dirt and rubble fill was laid down ahead of the 1915 Panama-Pacifica International Exposition, which celebrated San Francisco's rebirth after the 1906 earthquake and fire that devastated the city.USGS' Zoback estimated that an earthquake of the same magnitude as the 1906 temblor would destroy 40 percent of San Francisco's buildings.Major earthquakes on the Hayward Fault occur on average every 140 years, according to Brocher — so the fault line is overdue for a temblor by eight years. The houses on the hillside have more protection. This map shows the liquefaction hazard in the communities of Alameda, Berkeley, Emeryville, Oakland, and Piedmont for a magnitude 7.1 earthquake on the Hayward fault. Liquefaction Hazard Maps Source: USGS Open-File Reports 02-296 and 2008-1270 Northwestern Alameda County | Northern Santa Clara County. )The highest-risk area follows the creek along Woodland Avenue west to Downtown North and Stanford.The fact that you live in a high-risk liquefaction zone does not necessarily mean your house is in danger of damage should a temblor strike.The USGS map does not claim to be accurate within 50 meters, nor does it distinguish between old, poorly engineered fill and more modern, engineered artificial fill zones. This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. (Shown: A sinkhole that formed on Alvarado Boulevard in Union City closed roads and hindered traffic in October 2015. (Shown: A decorated green bicycle secured in the back of a car is seen driving toward South Van Ness Avenue in San Francisco's Mission District. (A more detailed map of the Marina's liquefaction zones can be found USGS' Zoback estimated that an earthquake of the same magnitude as the 1906 temblor would destroy 40 percent of San Francisco's buildings.Major earthquakes on the Hayward Fault occur on average every 140 years, according to Brocher — so the fault line is overdue for a temblor by eight years.