Recently, as co-authors who contributed equally, Professor Jiang Xiuyang from College of Geographical Sciences, FNU, Professor Liu Qingsong and Assistant Professor Zhou Youmin from Southern University of Science and Technology published an online paper entitled“Multidecadally resolved polarity oscillations during a geomagnetic excursion”in the internationally renowned academic journal Proceedings of the National Academy of Sciences of the United States of America(PNAS).
How fast does the geomagnetic field reverse? What is going on during the process? To find out the answers to the questions,theresearch team, led by Professor Jiang Xiuyang, have started a systematic investigation to the caves in the northern part of Guizhou Province since 2010. The four-year research found that the geomagnetic field was weak and unstable one hundred thousand years ago. An inter-hemispheric polarity excursion of the geomagnetic pole (currently north/south) only took a hundred years to several hundredsof years, and then the geomagnetic pole would rapidly rebound southward to the middle and low latitudes, and return slowly to the original position in the high latitude after hundreds to thousands of years. The phenomenon correlated with the geomagnetic dynamo action that originated in the interior of the earth. The research also found that an inter-hemispheric polarity excursion took only one hundred to two hundred years 98 thousand years ago.
The research was supported by the National Natural Science Foundation of China (NSFC) Grants 41372189 and 41672170.
(Translated by Wang Sijie, Reviewed by Xie Xiujuan)