Gary forwarded the first link and William the second (to the same story). See www.dailymail.co.uk/sciencetech/article-5062925/There-mysterious-geometr… … and https://phys.org/print429354456.html … unexpectedly high magnetic fields were identified in Jordan and Israel. C14 dating came up with 1000BC. It would seem that Earth's magnetic field rose and then fell back again by 100 per cent – in only 30 years. What led to the magnetic spike is not known but this has not stopped various theories from surfacing. Scientists say the spike offers a potentially new insight into the dynamics and evolution of Earth's interior. The assumption is that magnetism is driven by an internal dynamo. High field strengeths were found in Turkey, China and Georgia – but were absent from Egypt and Cyprus. The speculation is that the magnetic spike was around 2000m across and scientists are running with the idea a flow of iron in the outer liquid part of the core was at fault. One possibility is that the spike was drawn to the surface of the Earth's crust by an upwelling of fluid iron. This is all guesswork of course, but it is a story evolving.
Geomagnetic spike
15 November 2017Electromagnetism