: Photo: Courtesy The Bancroft LibraryA major earthquake struck the Hayward fault in the eastern San Francisco Bay Area on Oct. 21, 1868. Though only a few thousand people lived on the east side of the bay at the time, the magnitude 7 quake took 30 lives and damaged nearly every building within several miles of the 160-mile-long fault.
The quake also did considerable damage in San Francisco, and became known as the Great San Francisco Earthquake until it was eclipsed by a larger jolt in 1906.
By digging trenches across the Hayward fault, geologists have found evidence of 10 more major prehistoric quakes over the last 2,000 years. The average time between those earthquakes is 140 years. With exactly 140 years since the last major quake, the Hayward fault could rock the Bay Area any day now.
With close to two million people living along the fault today, the losses would be much, much greater. To learn what a repeat of the 1868 earthquake would be like without the help of modern seismographs, scientists rely on photos such as those shown here and personal accounts of the event.
Court House, San LeandroLeft: The second floor of the courthouse collapsed in San Leandro, California, the town just north of Hayward. Afterward, the Alameda County seat was moved from San Leandro to Oakland.
: Photo: Courtesy The Bancroft LibraryAlmost every building in Hayward collapsed or was severely damaged, including this flour mill.
: Photo: William Shew/Courtesy The Bancroft LibraryThe Davis-Estudillo house in San Leandro was one of only two adobe buildings reported as damaged by the newspapers. There were actually more than a dozen others, all of which were razed within a decade of the quake.
: Photo: Courtesy The Bancroft Library The epicenter of the 1868 earthquake was likely near Hayward, but the shaking did considerable damage to buildings such as this one, more than 20 miles away in San Francisco.
: Photo: Courtesy The Bancroft LibraryThe earthquake did enough damage in San Francisco to earn it the title The Great San Francisco Earthquake, which it held until 1906, when a quake 30 times as powerful struck just outside the city.
: Photo: Courtesy The Bancroft Library Five of the 30 people killed by the 1868 quake were in San Francisco, which was then the largest city on the West Coast, with a population around 150,000 at the time.
: Photo: Courtesy The Bancroft LibraryPeople can be seen here surveying the extensive damage to Morse & Heslep's flour mill in Hayward.
: Photo: Courtesy The Bancroft LibraryAreas of San Francisco on "reclaimed ground" made of landfill suffered more damage. Loose sediment can behave momentarily as a liquid when shaken, causing buildings to founder.
: Photo: Courtesy The Bancroft LibraryMany of the few thousand people on the east side of San Francisco Bay were left homeless by the 1868 earthquake. If a similar quake were to strike the Hayward fault today, more than 200,000 people could be displaced.
: Photo: Courtesy The Bancroft LibraryOne side of the foundation of this house in Hayward collapsed during the quake, though the building was otherwise intact.
: Photo: Theodore KytkaA major earthquake somewhere in California is virtually a certainty in the next 30 years, according to the U.S. Geological Survey. Some of the most hazardous regions of the state are also the most populated, including Los Angeles and the San Francisco Bay Area. A major quake in one of these areas is guaranteed to be a disaster that will take many lives.
The United States has already had several deadly earthquakes. Over the past 140 years, major quakes have struck Alaska, Hawaii, California and even South Carolina and killed at least 60, but in some cases hundreds of people. The country's most famous earthquake killed 3,000 or more people in San Francisco in 1906. But geologists estimate the next big one to hit the Bay Area would surely make this list of the 10 deadliest in the country's history.
Left: The 1906 San Francisco earthquake measured a magnitude 7.9 and ruptured 300 miles of the San Andreas Fault, which slipped as much as 20 feet in some places. Historians estimate that more than 3,000 people died in the quake and the ensuing fire, making it the deadliest earthquake in U.S. history. This photo, taken several months after the earthquake, shows the devastation, including the ruins of City Hall.
: Photo: CorbisIn 1946, a magnitude 8.1 earthquake on Unimak Island in Alaska triggered a tsunami that killed 159 people in Hawaii, five in Alaska and one in California. In this photo, a man (see arrow) is about to be killed by the wave in Hilo, Hawaii.
: Photo courtesy U.S. Geological SurveyThe second-largest earthquake ever recorded was a magnitude 9.2 in Alaska's Prince William Sound in 1964. That quake caused the ground to shift vertically by as much as 50 feet in places. A 130-acre landslide demolished 75 homes. The resulting tsunami reached heights of 220 feet in places. In all, 128 people lost their lives, most killed by the tsunami, including 11 people in Crescent City, California.
: Photo: W.W. BradleyThis road in Long Beach, California, was damaged by a magnitude 6.3 earthquake in 1933. Despite its lower magnitude, the quake killed 115 people and seriously damaged structures made of unreinforced masonry from Los Angeles to Laguna Beach, California. The damage to schools in the area prompted a mandate for better construction. Lessons from the quake were incorporated into the state's building code in the following years.
: Photo: Courtesy Hawaiian Historical SocietyIn 1868, a massive, sudden movement of the south flank of Hawaii's Big Island caused a magnitude 7.9 earthquake that triggered a tsunami and landslides that killed 77 people. All major earthquakes in Hawaii are related to the volcanoes there. In this case, the magma pushing up from below the earth's crust forced the side of the island to expand, sliding along the ocean crust and causing a major earthquake.
: Photo courtesy U.S. Geological SurveyThough the 1971 San Fernando quake was a relatively moderate magnitude 6.6 and was centered in a sparsely populated, mountainous area outside of town, 65 people died and 2,000 were injured. Some of the most spectacular damage occurred at Olive View Hospital in Sylmar, California, pictured here, where 49 people died despite newly built, supposedly earthquake-resistant construction.
: Photo: J.K. Nakata/U.S. Geological SurveyThe 1989 Loma Prieta earthquake was the largest to strike the San Francisco Bay Area since the 1906 quake. The magnitude 6.9 quake was centered in the Santa Cruz mountains, 60 miles south of San Francisco and Oakland, but still managed to damage $6 billion worth of property and kill 63 people, most of them on a collapsed highway in Oakland. A car is shown crushed by houses in San Francisco.
: Photo: Pierre St. AmandThe magnitude 9.4 Valdivia, Chile, earthquake in 1960 is the largest ever recorded. It killed around 1,600 people and left 2 million homeless in southern Chile. Even quality wooden homes, shown here, were destroyed. The resulting tsunami killed 138 people in Japan and 61 people in Hawaii, making it one of the deadliest quakes in U.S. history despite happening on another continent.
: The 1994 magnitude 6.7 earthquake that rocked Northridge in Southern California exposed major weaknesses in the building codes. Many of the 60 people who died lost their lives because buildings had weak lower stories, such as parking garages under apartment buildings. The Northridge quake caused $20 billion in damage.
: Photo courtesy U.S. Geological SurveyIn 1886, one of the largest earthquakes ever recorded in the eastern United States struck Charleston, South Carolina, killing 60 people. Almost no buildings in the city were left undamaged. More than 100 years later, the cause of this quake is still not well understood. A damaged brick house and street in Charleston are shown here.
: Image: Walt Feimer/Goddard Space Flight CenterNASA will launch its Interstellar Boundary Explorer (IBEX) Oct. 19, on a mission to explore the interaction of our sun and solar system with the galaxy. IBEX will orbit 200,000 miles above the Earth and capture the first-ever images of our solar system's boundaries.
The mission will help us visualize our place in the galaxy and learn how the interaction between our sun and the galaxy beyond may have evolved. Scientists will get a better look at the solar wind — the outer layer of the sun's atmosphere that is expanding out into the galaxy as a plasma moving at a million miles an hour. The plasma creates a bubble, known as the heliosphere, that protects the solar system against radiation from galactic cosmic rays.
Left: Once the IBEX spacecraft is in low-Earth orbit, a solid rocket motor will burn for 75 seconds to give it a final boost into position, pointing at the sun and ready to deliver data.
: Photo: Southwest Research Institute Once the hardware and software was loaded aboard IBEX, technicians performed a series of stress tests. The spin test is shown here.
: Image: NASA GSFCThe primary mission of IBEX is to explore the edge of our solar system and how it interacts with the galaxy beyond.
: Image: NASA GSFCThe heliosphere, pictured here, separates our solar system from the interstellar medium and fends off galactic cosmic rays.
: Image: Walt Feimer/Goddard Space Flight CenterIBEX will study coronal mass ejections, depicted here, which are flows of plasma made up primarily of electrons and protons that propagate from the sun.
: Photo: Southwest Research InstituteOne of IBEX's two sensors. Each time an energetic neutral atom comes into one of the sensors, it is recorded.
: Photo: Southwest Research InstituteOne of two sensors aboard IBEX is shown here. As the spacecraft slowly rotates, its sensors will capture information from the entire 360 degrees in a process that takes six months.
: Photo: Southwest Research InstituteEngineers work in a clean room using jumper cables to test the connections between the side panels (shown at left and right) that hold the sensors and the rest of the spacecraft (center).
: Photo: Southwest Research InstituteThe complete IBEX payload with both sensors is inserted into the thermal vacuum chamber for testing in space-like conditions.
: Photo: NASA/VAFBThe IBEX spacecraft is mounted on the front of the Pegasus rocket prior to being enclosed in the protective outer fairing.
: Photo: Southwest Research InstituteTechnicians at Vandenberg Air Force Base in California help guide the Star-27 kick motor and nozzle that will propel IBEX during the final leg of its journey into orbit.
: Photo: Southwest Research InstituteInside a protected clean room tent at Vandenberg Air Force Base, both halves of the fairing are installed around the IBEX spacecraft. The fairing is a molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent.