As igneous rocks crystallize from magma on the ocean floor, small, magnetic iron-bearing minerals align themselves with the Earth’s polarization at the time. The paleomagnetism specialist determines the magnetic orientation of these crystals. He/she uses specialized tools that detect the inclination (steepness) and declination (compass directions) of the magnetic pieces found in a core sample. The Super Conducting Cryogenic Magnetometer does this by placing the core sample into a special chamber that removes the interference of Earth’s present magnetic field. It then measures the sample’s magnetic field in three main directions -- X, Y and Z. This information enables the scientist to create a picture of Earth’s past polarization. He/she can then compare the sample to the known historic record and figure out from where and in what direction the sample has traveled. The reason for the changes in polarity is still a mystery to scientists. They do know, however, that it happens about every 6000 to 10,000 years.

So how does this reversal of the poles happen? The Earth’s core creates a magnetic field. In time, the polarization of the core begins to shift from a dipole scenario to one with multiple poles or less concentration at the poles. During this transition time, the strength of Earth’s magnetic field disperses, allowing additional radiation to be absorbed by the Earth. This transition time does not always come to fruition with a reversal of the poles; sometimes the polarization returns to its “normal” position: magnetic north.

For more information on paleomagnetism, click here. 

Staff Name: Klayton Kurtis

Majors: Geology, physics

Education: Western Washington University, WA

Courses: Plate tectonics, Geotectonics, Geophysics, Geochemistry, Geomorphology, Environmental Geology

Experiences: Geology internships/fellowships, research cruises, field camps

IODP Experience: Expedition 312 - 3rd Leg

Interests: Rocks and minerals, earth history, plate tectonics

Life Experience: Chief Mate on Adventure Cruises

Interests: sailing, running, rock climbing, travel

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