At https://www.livescience.com/archaeology/earths-magnetic-field-is-weakening-magnetic-crystals-from-lost-civilizations-could-hold-the-key-to-understanding-why … artifacts from the Iron Age revealed an intense historical magnetic anomaly in the Levant during the first millennium BC. Could using a similar technique help us understand why the Earth’s magnetic field appears to be weakening. An archaeologist at Tel Aviv University came across a piece of copper slag. This showed up an intense spike in Earth’s magnetic field. The magnitude of the spike was unprecented – in the experience of modern scientists. There was no model they could turn to in order to try and understand what had happened.
One explanation of the spike was that the archaeologist involved, and his geologist co-researcher, were using an entirely new technique – archaeomagnetism. With this, geophysicists are able to peer into magnetic particles inside archaeological material such as metal waste, as in this instance, as well as fired pottery and building stone. The idea is to recreate Earth’s magnetic past. Knowing what the magnetic field did in the past may help to predicts its future. Some geophysicists claim the Earth’s magnetic field is currently weakening. Others do not. In 2001 the magnetic north pole was closer to the northern tip of Canada. By 2007 it had shifted 200 miles closer to the geographic North Pole. Two lobes of strong magnetism, or flux patches, in the outer core beneath Canada and Siberia are thought to act as funnels for the magnetic field. When these lobes shift they move the magnetic poles. Why they shift is left unsaid. However, most of Earth’s magnetic field lines go north to south. A fifth of them digress – forming swirling eddies known as magnetic anomalies. This process is poorly understood. Scientists are building a global data base, Geomagia50, at the University of Minnesota. At the moment, 90 per cent of data comes from Europe. Africa is far behind. In spite of this, the Levantine magnetic spike has been found in China and Korea. They do not mention Russian investigations of magnetic excursions that are also dated to the first half of the Iron Age. Probably because that research dates back a few decades prior to western interest in magnetic anomalies. They were not keen on them in previous decades – and ignored the Russian evidence. It was unwelcome.