Computing magnetic declination

[Bazisuanming]

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[dean]

Thanks BZSM, I've added the link to my bookmarks. Helps when looking through google earth as well.

Cheers
Dean

[weikee]

i find we can use google map, and calculate the direction and compensate with the information we have (from the link) and find the direction without going to the house use a lopan. is pretty accurate, i try doing it for some the house i am interested in. measurement seem to be accurate.

[Bazisuanming]

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[weikee]

my first 2 house measurement done one month ago was so accurate google map and true north measurement, but slight off by 1 deg using lopan. i was really amaze with google map 

now with my spoiled Lopan, got to depend on the google map for the first assessment.

[Paivi]

If I may post this:

 newbielink:http://geomag.nrcan.gc.ca/apps/mdcal-eng.php [nonactive]

I use both this and the Nooa calculator.  This Canadian one takes into account also the minutes while Nooa goes further back in years.  Sometimes they give a little bit different results.

[weikee]

Hello guys,

Maybe the reading for some house will change, and our Bazi timing  after the Chile earthquake..

<http://www.tothecenter.com/news.php?readmore=12410>


SPACE.com Space.com Staff

The massive 8.8 earthquake that struck Chile may have changed the entire Earth's rotation and shortened the length of days on our planet, a NASA scientist said Monday.

The quake, the seventh strongest earthquake in recorded history, hit Chile Saturday and should have shortened the length of an Earth day by 1.26 milliseconds, according to research scientist Richard Gross at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"Perhaps more impressive is how much the quake shifted Earth's axis," NASA officials said in a Monday update.

The computer model used by Gross and his colleagues to determine the effects of the Chile earthquake effect also found that it should have moved Earth's figure axis by about 3 inches (8 cm or 27 milliarcseconds). 

The Earth's figure axis is not the same as its north-south axis, which it spins around once every day at a speed of about 1,000 mph (1,604 kph).

The figure axis is the axis around which the Earth's mass is balanced. It is offset from the Earth's north-south axis by about 33 feet (10 meters).

Strong earthquakes have altered Earth's days and its axis in the past. The 9.1 Sumatran earthquake in 2004, which set off a deadly tsunami, should have shortened Earth's days by 6.8 microseconds and shifted its axis by about 2.76 inches (7 cm, or 2.32 milliarcseconds).