A reversal in Earth's magnetic field thousands of years ago plunged the planet into an environmental crisis that may have resembled "a disaster movie," scientists recently discovered. Our planet 's magnetic field is dynamic and, numerous times, it has flipped — when the magnetic North and South Poles swap places. In our electronics-dependent world, such a reversal could seriously disrupt communication networks. But the impact could be even more serious than that, according to the new study.
Earth’s Magnetic Field Reversal 42,000 Years Ago Triggered a Global Environmental Crisis
Earth's magnetic field broke down 42, years ago and caused massive sudden climate change
Ancient kauri tree log from Ngawha, New Zealand. Credit: Nelson Parker. Radiocarbon measurements on the remains of 42,year-old New Zealand kauri trees provide the basis for better calibration of geological archives of this period. Radiocarbon analyses of the remains of kauri trees from New Zealand now make it possible for the first time to precisely time and analyze this event and its associated effects, as well as to calibrate geological archives such as sediment and ice cores from this period. Their causes, course, and effects are not yet fully understood.
Earth's magnetic field
Radiometric dating , radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon , in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. Together with stratigraphic principles , radiometric dating methods are used in geochronology to establish the geologic time scale. By allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change.
Since , scientists have reckoned the ages of many old objects by measuring the amounts of radioactive carbon they contain. New research shows, however, that some estimates based on carbon may have erred by thousands of years. It is too soon to know whether the discovery will seriously upset the estimated dates of events like the arrival of human beings in the Western Hemisphere, scientists said.