The first step is to determine the latitude and longitude of your
point of interest. One resource for this is
which does a free ZIP code lookup (the success of this option depends
on how large your ZIP code is!), or the
Query form for geographical features.
Once you have the coordinates,
decide whether the northern California or the global catalog is more
appropriate for your search. Once you have selected the catalog,
use the delta feature of "additional search parameters"
in the form to specify your point of interest.
For example, the coordinates of UC Berkeley in Berkeley, CA,
are 37.8735, -122.2609. To obtain a list of earthquakes within
2 km of these coordinates, enter
This will return all events within a 2 km radius circle of the
specified coordinates. When this search is run on the NCSN catalog
for the year 2001 for all magnitudes, it returns 1 earthquake:
2001/01/30 10:35:34.36 37.8785 -122.2473 9.29 1.05 coda
If your search does not return any earthquakes, consider enlarging the
radius of your circle (remember, the circle radius is specified in
kilometers, not miles!). If you need help with the conversion,
try out our converter.
Or double check the sign of longitude. The
catalog search requires that West longitudes are specified with
For more details, please see the help pages for either the
Global earthquake catalog