1868 Hayward earthquake facts for kids
Damage to the Alameda County courthouse with inset showing building before the earthquake
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| UTC time | 1868-10-21 15:53 |
|---|---|
| USGS-ANSS | ComCat |
| Local date | October 21, 1868 |
| Local time | 07:53 |
| Magnitude | 6.3–6.7 Mw |
| Epicenter | 37°42′N 122°06′W / 37.7°N 122.1°W |
| Fault | Hayward Fault Zone |
| Type | Strike-slip |
| Areas affected | San Francisco Bay Area California United States |
| Total damage | $350,000 / Moderate |
| Max. intensity | IX (Violent) |
| Casualties | 30 |
The 1868 Hayward earthquake happened in the San Francisco Bay Area in California, USA. It struck on October 21, 1868. This was a powerful earthquake, estimated to be between 6.3 and 6.7 on the moment magnitude scale. It caused a lot of damage and sadly, some people died. Before the even bigger 1906 San Francisco earthquake, people called this one the "Great San Francisco earthquake." It was the last major earthquake on the Hayward Fault Zone for a long time.
Understanding the 1868 Hayward Earthquake
The earthquake happened at 7:53 in the morning on October 21, 1868. Scientists believe its starting point, called the epicenter, was near Hayward, California. The earthquake's strength was measured between 6.3 and 6.7 on the moment magnitude scale.
When the ground shook, it caused a crack on the surface. This crack was about 20 miles long. It stretched from San Leandro all the way to what is now the Warm Springs area in Fremont.
How the Earthquake Caused Damage
The town of Hayward was hit the hardest. Almost every building there was either destroyed or badly damaged. The Alameda County Courthouse in San Leandro was also destroyed. Because of this, the county's main office moved to Oakland, where it is today.
The old adobe chapel at Mission San José in Fremont was also ruined. Many buildings in San Jose, San Francisco, and all over Alameda County were damaged too. Reports of damage came from as far north as Santa Rosa and as far south as Gilroy and Santa Cruz. About 30 people lost their lives because of the earthquake.
Measuring the Earthquake's Strength
The United States Geological Survey (USGS) studies earthquakes. They estimated that Hayward felt very strong shaking, called IX (Violent) on the Modified Mercalli Intensity scale. This scale describes how much people feel an earthquake and how much damage it causes.
- San Leandro experienced shaking that was VIII (Severe).
- San Francisco and Oakland felt shaking that was VII (Very strong).
