Questions tagged [paleomagnetism]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
4 votes
1 answer
46 views

Can paleomagnetic techniques determine the exact direction of Earth's magnetic poles in the past, not just their polarity?

Since our planet's magnetic poles are not usually, precisely, lined up with the geographic poles of Earth's axis, and since they move around a lot, can paleomagneticists (is that a word?) determine ...
user avatar
2 votes
1 answer
43 views

How accurate are paleomagnetic orientation measurements?

I am curious what the modern accuracy for paleomagnetic azimuthal orientation measurements are. Let's say for a magnetite grain, is the orientation of the magnetic moment for a single crystal resolved ...
user avatar
0 votes
0 answers
45 views

More iron = Less remanent magnetic field

I am aware that iron is a magnetic mineral and through the process of thermoremanent magnetization it can store a record to the state of magnetization it formed in. I wanted to ask if there are any ...
user avatar
2 votes
0 answers
64 views

What is the relative (magnetic) permeability of the Earth? How could it be measured?

I believe, Earth could be approximated by a molten, metallic, non-magnetic sphere, with a molten stony sphere around it. However, As far I know, the magnetic properties of the lava in the crust, in ...
user avatar
  • 652
7 votes
2 answers
265 views

Is there evidence of multiple poles (higher order than dipole) in earth's magnetic field?

There is this slightly uncombed simulation model of a geomagnetic field reversal, showing multiple poles, a quadrupole or even higher order magnetic field. Earth's magnetic field is mostly described ...
user avatar
5 votes
1 answer
292 views

What happens when the North and South poles flip?

How long does it take the magnetic field to move once the poles start to flip? What environmentally would change? Does the core of the Earth flip? The magnetic poles are moving now. When will it ...
user avatar
  • 1
13 votes
3 answers
2k views

Does the magnetic field really protect Earth from anything?

Many topics discussed here in Earth Science SE, tend to be about facts that are of consensus in the scientific community but not widely accepted by the general public. Instead, this one is widely ...
user avatar
  • 17.1k
13 votes
2 answers
3k views

How long does a magnetic pole reversal take to complete?

Geomagnetic pole reversal is a "regular" phenomenon on Earth. Although the interval pattern has been irregular at times (sometimes with millions of years of difference between change intervals), Earth ...
user avatar
1 vote
0 answers
63 views

Is it possible that a change of the earth magnetic poles influences deep-sea currents?

A deepwater circulation had changed direction about 55 million years ago, whereby salt cold water went from north to south. This was seen after research of foraminifera with carbon isotope change. But ...
user avatar
  • 2,493
4 votes
1 answer
188 views

Are the magnetic elements of meteorites that have struck Earth aligned with the magnetic field?

I was just pondering this question; do meteorites containing significant magnetic metal elements displace paleomagnetism the same way that magnetic striping on the ocean floor occurs? When the ...
user avatar
  • 43
6 votes
1 answer
286 views

How did the intensity of Earth's magnetic field change through geological time?

Looking at the wikipedia article on the Earth's magnetic field, I see that its strength varies through time. How did Earth's magnetic field change throughout its history, from the beginning of the ...
user avatar
  • 163
6 votes
2 answers
119 views

Could the magnetic field influence tectonic forces

Paleomagnetism can be measured as the magnetic field at the time of rock forming is preserved in some minerals. Could the paleomagnetism and the present magnetic field somehow influence the movements ...
user avatar
  • 83
24 votes
0 answers
360 views

How reliable were early measurements of palaeomagnetic directions?

The methodology and equipment for palaeomagnetic studies in the 1960s and 1970s was often rather primitive by today's standards. For example, Doell and Cox (1967) imply that the standard procedure for ...
user avatar
  • 5,380
3 votes
1 answer
627 views

Help determining virtual geomagnetic pole

Magnetic measurements have been made on some lavas found at 60ºN and 90ºW. The inclination angle is 37º. If the horizontal direction of magnetism of these lavas is due west, calculate the position of ...
user avatar
  • 39
9 votes
2 answers
412 views

How are paleomagnetic polarities determined?

In magnetostratigraphic logs various chrons are distinguished with either normal or reversed polarity, with the magnetic north pole at the geographic north and south pole, respectively. How and why ...
user avatar
  • 2,612
20 votes
1 answer
373 views

Why Earth's magnetic poles are (and were) in their positions?

This is a sort of a follow-up question to What causes the Earth to have magnetic poles? The Earth has magnetic fields, and according to dynamo theory I roughly understand why. If the Earth's rotation ...
user avatar
  • 956
17 votes
2 answers
2k views

What causes the Earth to have magnetic poles?

A compass can tell me the directions of the Earth's North and South poles? What is it about the Earth that produces this "polarity" such that a compass can pick it up? The first thing that jumped ...
user avatar
  • 7,366