The DoD World Magnetic Model predicts for 1 March 2004 at the given location a magnetic declination of 4.06 degrees (compass will theoretically point 4.06 degrees to the east of "true" north). A different magnetic model, the International Geomganetic Reference Field, gives 4.22 degrees. Take your pick. Local iron deposits, geomagnetic activity, etc. could have an effect on the compass reading. Incidentally, the WMM magnetic dip is 82.11 degrees -- the magnetic field lines are almost vertical. For this reason, the horizontal field strength (to which the compass is sensitive) is not as strong as that at more southerly locations. Any further north (or, more precisely, towards the north magnetic pole) and a compass starts to become erratic. More info here <http://www.ngdc.noaa.gov/seg/potfld/faqgeom.shtml>. Have fun. -- Richard Langley Professor of Geodesy and Precision Navigation
On Sat, 28 Feb 2004, tony moss wrote: >Fellow Shadow Watchers, > Next week I will be setting off for Longyearbyen on >Spitsbergen in the Svalbard group of islands 500 miles north of Tromso to >install their new 24 hour stainless steel sundial. As any diallist is >painfully aware the most probable event for dial installation is an obscured >sun all day so for the purposes of the inauguration ceremony and photoshoot >we may be forced to do the diallistically unspeakable viz. a temporary >magnetic alignment so that at least it looks OK -ish. > >Having consulted various geomagnetic websites for that area, like Omar >Khayyam, I "Came out by the same Door as in I went" because the magnetic map >at 78° 12' North 15° 40' is exceedingly complex. > >Can anyone tell me the likely current magnetic variation at those coordinates >please? > >Thanks in anticipation. > >Tony Moss > >P.S. I bought my snow boots yesterday and overnight we had a full six inches >of white stuff in which to try them out so I hope the same Good Luck continues. > >- > =============================================================================== Richard B. Langley E-mail: [EMAIL PROTECTED] Geodetic Research Laboratory Web: http://www.unb.ca/GGE/ Dept. of Geodesy and Geomatics Engineering Phone: +1 506 453-5142 University of New Brunswick Fax: +1 506 453-4943 Fredericton, N.B., Canada E3B 5A3 Fredericton? Where's that? See: http://www.city.fredericton.nb.ca/ =============================================================================== -
