How Well Can We Know the Ancient Geomagnetic Field?

Explore the challenges and advancements in understanding the ancient geomagnetic field through paleomagnetic recordings in this 57-minute lecture by Wyn Williams from the Earth Sciences department at the University of Liverpool. Delve into the complexities of studying the Earth's magnetic field evolution over billions of years, examining how structural, chemical, and thermal changes have influenced its power and shape. Investigate the difficulties in obtaining reliable paleomagnetic records and the high failure rates in paleointensity surveys. Learn about recent discoveries in magnetic domain structures, including single vortex (SV) states in pseudo-single-domain (PSD) grains and their similarities to both single domain (SD) and multidomain (MD) grains. Analyze the behavior of SV states as a function of time and temperature, and examine the reciprocity of magnetic blocking and unblocking in PSD grains. Gain insights into the current state of paleomagnetic research and its implications for understanding the ancient geomagnetic field.