M 4.2 - 4 km ESE of Piedmont, California
July 20, 2007 at 11:42:22 UTC
Depth: 5.26 km (Shallow)
Key Takeaway
This light earthquake (M4.2) occurred 18 years ago near 4 km ESE of Piedmont, California, at a depth of 5.26 km (shallow). It was felt by 10,917 people.
Light
PAGER Alert
Tsunami
Felt Reports
Event Details
| Magnitude | 4.2 mw |
| Depth | 5.26 km (Shallow) |
| Location | 37.8040N, 122.1930W |
| Community Intensity | V (Moderate) |
| Mercalli Intensity | V (Moderate) |
| Felt Reports (DYFI) | 10,917 people |
| Tsunami Warning | No |
| Significance | 801 / 3000 |
| Status | Reviewed |
| Network | nc |
| USGS Event Page | View on USGS → |
Frequently Asked Questions
What was the magnitude of this earthquake?
This earthquake had a magnitude of 4.2, classified as "Light". Light earthquakes produce noticeable shaking but rarely cause damage.
How deep was this earthquake?
This earthquake occurred at a depth of 5.26 km, classified as "Shallow". Shallow earthquakes tend to cause more damage at the surface because the energy has less distance to travel before reaching buildings and infrastructure.
Where exactly did this earthquake occur?
This earthquake occurred near 4 km ESE of Piedmont, California, at coordinates 37.8040N, 122.1930W. The location is determined by analyzing seismic wave arrival times at multiple monitoring stations.
Were there aftershocks associated with this event?
Aftershock data for this specific event can be explored by viewing nearby recent earthquakes listed below on this page. Aftershocks are smaller earthquakes that occur in the same area following a larger event, and they can continue for days, weeks, or even months depending on the original earthquake's magnitude.
What does the magnitude of this earthquake mean in practical terms?
A magnitude 4.2 earthquake is classified as "Light" — these are commonly felt by people indoors but rarely cause any significant damage.
Nearby Recent Earthquakes
More Earthquakes in US
228 km ESE of Attu Station, Alaska
22 hours ago · 9.34 km deep
229 km ESE of Attu Station, Alaska
1 day ago · 0.80 km deep
33 km S of Funny River, Alaska
1 day ago · 51.50 km deep
228 km ESE of Attu Station, Alaska
1 day ago · 10.00 km deep
239 km ESE of Attu Station, Alaska
1 day ago · 5.71 km deep
96 km S of Nikolski, Alaska
1 day ago · 17.00 km deep
231 km ESE of Attu Station, Alaska
2 days ago · 10.00 km deep
231 km ESE of Attu Station, Alaska
2 days ago · 10.00 km deep
More M4.0-5.0 Earthquakes
21 km ENE of Sallique, Peru
2 hours ago · 41.95 km deep
16 km SSE of Petropavlovsk-Kamchatsky, Russia
10 hours ago · 79.51 km deep
2 km SSE of Santa María Ixhuatán, Guatemala
11 hours ago · 10.00 km deep
148 km SSE of Vilyuchinsk, Russia
11 hours ago · 35.00 km deep
17 km ESE of Manay, Philippines
13 hours ago · 80.55 km deep
northern Mid-Atlantic Ridge
15 hours ago · 10.00 km deep
61 km SSW of Ashkāsham, Afghanistan
15 hours ago · 101.97 km deep
74 km W of Bandar Abbas, Iran
16 hours ago · 10.00 km deep
Data from the USGS Earthquake Hazards Program (ComCat). QuakeScan is not affiliated with the USGS. Event details may be updated as new data becomes available.