<blockquote>
  <p>In other words where might be a natural place on Earth that would over power a compass and then some</p>
</blockquote>

<p>Just about anywhere where the rocks are rich in iron. This would occur near iron ore, basalt, gabbro, and similar iron-rich rocks. You really don't need a lot of magnetite in the rock for this to move the compass needle. You don't even need magnetite - chromite or pyrrhotite rich rocks may be enough to move the compass needle off.</p>

<p>This is a common problem when navigating only using a compass in basalt rich areas. A good historical example is that of Tasmania. You can read about it the following article:</p>

<p><a href="https://eprints.utas.edu.au/13644/1/1997_Leaman_Magnetic_rst.pdf" rel="nofollow noreferrer">Magnetic rocks—their effect on compass use and navigation in Tasmania</a></p>

<p>As for a map, you're probably looking for a magnetic anomaly map.</p>

<p><a href="http://geomag.org/models/wdmam.html" rel="nofollow noreferrer">Here's an attempt to make a global</a> , or this one from <a href="https://crustal.usgs.gov/projects/namad/" rel="nofollow noreferrer">USGS</a>, or this one being <a href="https://ccgm.org/en/maps/113-carte-des-anomalies-magnetiques-du-monde.html" rel="nofollow noreferrer">offered for sale</a>.</p>

CC BY-SA 4.0
2018-09-09T09:22:26.937Z
2018-09-10T00:23:58.643Z
2018-09-10T00:23:58.643Z
Gimelist
<p>Is there anywhere that magnetic ore deposits are strong enough to have a magnetic field that would be stronger then 
Earths' magnetic poles by proximity? </p>

<p>I'm not asking <a href="https://earthscience.stackexchange.com/questions/13854/where-on-earth-is-the-magnetic-field-intensity-stronger">Where on Earth is the magnetic field intensity stronger?</a> In other words where might be a natural place on Earth that would over power a compass and then some? Is there a map of those magnetic field lines minus the Earths' polar magnetic field lines? </p>

<geophysics><geomagnetism><mapping><field-measurements><ore>
Where on Earth is the highest none polar magnetic fields?
Muze
# Where on Earth is the highest none polar magnetic fields?

(Asked by: username_0 on 2018-09-08)

Is there anywhere that magnetic ore deposits are strong enough to have a magnetic field that would be stronger then
Earths' magnetic poles by proximity?

I'm not asking [Where on Earth is the magnetic field intensity stronger?](https://earthscience.stackexchange.com/questions/13854/where-on-earth-is-the-magnetic-field-intensity-stronger) In other words where might be a natural place on Earth that would over power a compass and then some? Is there a map of those magnetic field lines minus the Earths' polar magnetic field lines?

**Tags:** geophysics, geomagnetism, mapping, field-measurements, ore


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## 1 answers

### Answer by username_1 on 2018-09-09. Score: 4 | Accepted answer

> In other words where might be a natural place on Earth that would over power a compass and then some

Just about anywhere where the rocks are rich in iron. This would occur near iron ore, basalt, gabbro, and similar iron-rich rocks. You really don't need a lot of magnetite in the rock for this to move the compass needle. You don't even need magnetite - chromite or pyrrhotite rich rocks may be enough to move the compass needle off.

This is a common problem when navigating only using a compass in basalt rich areas. A good historical example is that of Tasmania. You can read about it the following article:

[Magnetic rocks—their effect on compass use and navigation in Tasmania](https://eprints.utas.edu.au/13644/1/1997_Leaman_Magnetic_rst.pdf)

As for a map, you're probably looking for a magnetic anomaly map.

[Here's an attempt to make a global](http://geomag.org/models/wdmam.html) , or this one from [USGS](https://crustal.usgs.gov/projects/namad/), or this one being [offered for sale](https://ccgm.org/en/maps/113-carte-des-anomalies-magnetiques-du-monde.html).


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