magnetisaatioaika

Magnetisaatioaika, also known as the Paleomagnetic Chron, is a time scale used in geology and archaeology to date rocks and artifacts based on their magnetic properties. It is analogous to the geological time scale but is based on the magnetic field reversals recorded in the Earth's crust. The concept was first introduced by Motonori Matuyama in 1929, who observed that the Earth's magnetic field had reversed polarity multiple times in the past.

The magnetisaatioaika is divided into epochs, which are further subdivided into polarity chrons. Each chron represents a period during which the Earth's magnetic field maintained a consistent polarity. The most recent reversal, known as the Brunhes-Matuyama reversal, occurred approximately 780,000 years ago. The magnetisaatioaika is continuously refined as new data is collected, particularly from deep-sea sediment cores and lava flows.

This time scale is particularly useful in dating volcanic rocks, sediments, and archaeological materials that contain magnetic minerals such as magnetite. By measuring the direction and intensity of the magnetization in these materials, scientists can correlate them to specific polarity chrons and estimate their age. The magnetisaatioaika provides a valuable tool for understanding the Earth's magnetic history and the timing of geological and archaeological events.