Maximum Considered Ground Motion For The Conterminous US, used by IBC2000 and other building codes.
This is an external link furnished only as a library service by the Oklahoma Geological Survey (OGS). The OGS is not responsible for the contents of the link or its use.
The ground motion numbers should be used only in conjunction with IBC2000 or other building code.
There are several maps with similar names. Do not use any other map than exactly what is specified by the building code you are using.
The older, and probably obselete, maps showing zones of 0, 1, 2, 3, or 4 belong to older, and probably obselete, UBC building codes.
UBC 1994, an example of the 0, 1, 2, 3, 4 map. Obsolete for most purposes>
Even though IBC2000 and IBC2003 include the word "international", they are used only in the US.
On the linked page, you must enter latitude and longitude as decimal degrees, with a negative sign in front of the west longitude. Do not use minutes or seconds.
35.5 -95.5 correct
35.5 95.5 incorrect
35.5 N 95.5 W incorrect
35 deg 30 min 95 deg 30 min incorrect
35.4326 -96.3050 correct, this is for downtown Okemah, Okfuskee Co., OK
Find the latitude and longitude of your site using a GPS receiver,
ENTER LATITUDE AND LONGITUDE ON THE MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION LINK.
BE CERTAIN YOU ARE USING THE BUILDING CODE REQUIRED FOR YOUR PROJECT. IF THE POLITICAL JURISDICTION AND THE ENTITY ISSUING THE CALL FOR BIDS SPECIFY DIFFERENT CODES, YOU MUST DETERMINE WHICH CODE OR COMBINATION OF CODES PREVAIL.
THE OKLAHOMA GEOLOGICAL SURVEY (OGS) CAN NOT TELL YOU WHICH CODE TO USE OR HOW TO USE IT. THE EXTERNAL LINK IS PROVIDED ONLY AS A REFERENCE LIBRARY SERVICE FOR SITES WITHIN OKLAHOMA.
IF YOU ARE USING A MAP WITH ONLY ZONES 0, 1, 2, 3, AND 4, YOU ARE PROBABLY DOING IT WRONG. IF YOU USE A MAP BY ITSELF (NOT IN CONJUNCTION WITH A SPECIFIC CODE) YOU ARE PROBABLY WRONG.
THERE ARE SEVERAL CODES, AND MANY EARTHQUAKE GROUND MOTION MAPS. YOU MUST BE CERTAIN YOU ARE USING EXACTLY THE MAP SPECIFIED IN THE CODE YOU ARE USING.
THE INTERNATIONAL BUILDING CODE (IBC) MAPS ARE NOT THE SAME AS THE INTERNATIONAL RESIDENCE (IRC) MAPS.