The Hayward Fault Walk
in Central Park, Fremont
 joint project with Math Science Nucleus, City of Fremont, U.S. Geological Survey, California Geological Survey

 


The Fremont Earthquake Exhibit and Earthquake Patio

In 1962, the building known today as the Fremont Community Center was the original City Hall for the City of Fremont. The building was built on top of the Hayward Fault, and shows signs of creep from buckled beams and structural fractures. In 1972, the first sign of movement was found as a large crack in the council chamber. Today, the large crack continues to move.


In Fremont’s Central Park, the movement on the Hayward Fault has caused cracks in asphalt and concrete. The rate of movement is around 5 millimeters per year in the Fremont area, which is enough to visibly move concrete within a few years. The topography of Fremont’s Central Park was partially created by the Hayward Fault. Lake Elizabeth, a constructed lake, was a natural depression caused by movement on the fault.

 

The side of the building facing Lake Elizabeth shows several examples of tectonic movement caused by a strike-slip motion along the Hayward Fault. A strike-slip fault is when one land mass moves, nearly horizontally, in the opposite direction of the other on the surface. The movement on the patio reflects larger land structures that are forming throughout Central Park. Lake Elizabeth and Stivers Lagoon (south of lake) are larger depressions, while the hilly areas (north) reflect a compression. Strike-slip faults show transpressional compression (knolls) and
transtensional extension (depressions).

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earthquake patio 02
Wood and concrete react differently to constant fault creep. Look at the wood strips between the concrete and notice the wood is bending. As the wood bends, the concrete will crack. The inside of the building shows evidence of accumulated movement since the building  was constructed in 1962. Outside, the patio has also slowly shifted as seen in the concrete.
This knoll was created by opposite movement along the Hayward Fault cousing the gground to bend or fold. The bending or folding action caused land masses to slide past each other creating a compression ridge over time. Central Park has a rolling topography and depressions. The Knolls are caused when movement of strike-slip faults pushes the earth into a small hill. The pressure causes a movement upward called a positive flower structure.

 

 

WEB SPONSOR

  

The California Earthquake Authority (CEA) is a not-for-profit, privately funded, publicly managed organization that provides residential earthquake insurance and encourages sells Californians to reduce their risk of earthquake lost.  Learn more at EarthquakeAuthority.com. 

Math/Science Nucleus
 4074 Eggers Drive, Fremont, California, U.S.A., 94536
 (510) 790-6284
msn@msnucleus.org