USGS Frequently Asked Questions

FAQ's about Geomagnetism

What is declination?

How does a compass work?

What is a magnetic storm?

Is it true that the magnetic field occasionally reverses its polarity?

Does the Earth’s magnetic field affect human health?

Is the Earth a magnet?

Could the mass extinctions observed in the paleontological record be correlated with magnetic reversals?

Do animals use the magnetic field for orientation?

What are the hazardous effects of magnetic storms?

Do animals use the magnetic field for orientation?

What causes the magnetic field to reverse its polarity?

The strength of the magnetic field has been decreasing lately, does this mean that we are about to have a reversal?

How does the core generate a magnetic field?

What is a permanent magnet?

What is a magnetic field?

Why measure the magnetic field at the Earth’s surface? Wouldn’t satellites be better suited for space-weather studies?

Could magnetic reversals be caused by meteorite or cometary impacts? Could reversals be caused by melting of the polar ice caps or some sort of planetary alignment?

What about other magnetic fields, such as those from power lines, do they affect human health?

Why do models and charts of the geomagnetic field need to be periodically updated?

Are variations in the geomagnetic field somehow associated with earthquakes or vice versa?

What is space weather?

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