Total Magnetic Intensity (TMI) means, to many, to mean the total intensity of the earth’s magnetic field. That is, no IGRF correction.
But after IGRF correction, then it might be better to say “TMI Anomalies”. That is, anomalous to the total field. But if you really want to split hairs, TIMA might be more accurate: Total Intensity (describes the vector) Magnetic Anomalies (describes what you’re looking at). Depending upon where you’re at, some folks say “residual magnetic anomalies” meaning “TMI Anomalies” ( = IGRF removed). But then if the data are enhanced by filtering would that be the residual of the residual? J Cheers, Dale _________________________________________ So many windmills, So few Quixotes - John Lujan _________________________________________ Dale Bird, Ph.D. Bird Geophysical 16903 Clan Macintosh Houston, Texas 77084-1942 + 1-281-463-3816 Office + 1-281-463-7899 Fax + 1-713-203-1927 Mobile [email protected] www.birdgeo.com From: [email protected] [mailto:[email protected]] On Behalf Of SOLOMON YUSUF Sent: Thursday, August 28, 2014 9:53 AM To: Geosoft Oasis montaj and Target Subject: RE: [Bulk] [geonet] TMI OR RESIDUAL Sir If I understand you well I should use the Total magnetic intensity data after removing the IGRF....to calculate my spectral analysis and gm-sys models... Solomon On 28 Aug 2014 15:46, "Chris Vaughan" <[email protected]> wrote: Then you’ll want to watch the wavelength cutoff of the regional you remove. If sufficiently long, your target’s spectral response should come out about the same. Regards, Chris Chris Vaughan President and Chief Geophysicist, CGI Controlled Geophysics Inc. From: [email protected] [mailto:[email protected]] On Behalf Of SOLOMON YUSUF Sent: August-28-14 10:16 AM To: Geosoft Oasis montaj and Target Subject: RE: [Bulk] [geonet] TMI OR RESIDUAL I mean residual= TMI-regional data And TMI= TMI when IGRF was calculated. Thank you Solomon On 28 Aug 2014 14:58, "Chris Vaughan" <[email protected]> wrote: If by residual magnetics, you mean removal of the IGRF, then yes, that would be better, especially on a regional scale. Regards, Chris Chris Vaughan President and Chief Geophysicist, CGI Controlled Geophysics Inc. From: [email protected] [mailto:[email protected]] On Behalf Of SOLOMON YUSUF Sent: August-28-14 9:25 AM To: Geosoft Oasis montaj and Target Subject: [Bulk] [geonet] TMI OR RESIDUAL Dr all, Please I will like know which is better 1. Use TMI for spectral analysis and modelling when studying a sedimentary basin for basin configuration and sedimentary thickness Or 2. Use residual data for the analysis above. Solomon N. Yusuf PhD student Mautech, Nigeria. --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?fourm=geonet You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?fourm=geonet You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?fourm=geonet You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?fourm=geonet You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?fourm=geonet You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?fourm=geonet You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community
