Some USGS information accessed through this page may be preliminary in nature and presented prior to final review and approval by the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete, and conclusions drawn from such information are the sole responsibility of the user.
These are automatic computer generated maps and have not necessarily been checked by human oversight, so they may contain errors. Further, the input data for these maps are taken directly from the community of Internet users. While we make efforts to sort out unusual individual observations, the “net” product may still contain errors.
These maps are preliminary in nature and they will be updated frequently as data is supplemented by additional observations. It is important to reload your browser to see the update.
Locations within the same intensity area will not necessarily experience the same level of damage since damage depends heavily on the type of structure, the nature of the construction, and the details of the ground motion at that site, whereas a CIIM intensity value is intended to represent an average value for an entire ZIP code region. For this reason more or less damage than described in the intensity scale may occur.
Intensities assigned by Internet users alone are not official USGS Modified Mercalli Intensities. While calibrated to agree with the USGS MMI in some average sense, the should not be considered equivalent to the USGS MMI. Intensities reaching the damaging range (VI or higher) can only be considered reliable and authoritative if validated by the designated representative of the U.S. Geological Survey. This is not the case for these Internet user-based maps.
At present, the procedure for preparing the CIIM is new and experimental. Some aspects of the procedure may change in the future.