scholar : COJ must be very upset with Israeli archaeologists who consistently date the Fall of Jerusalem in 586 BCE
Neil, I like your sense of humour. You and COJ are strange bed-fellows. It should be noted that the geomagnetic field is not being used to date the destruction of Jerusalem, but the destruction of Jerusalem is used to date the geomagnetic field as it existed at that time. That is why the PLOS ONE article is entitled The Earth’s magnetic field in Jerusalem during the Babylonian destruction: A unique reference for field behavior and an anchor for archaeomagnetic dating.
The dating of the destruction of Jerusalem to 586 BCE is based on the book The fall and rise of Jerusalem: Judah under Babylonian rule, 2005, by Oded Lipschits, who is also one of the editors of the article. In a review of his book in The Journal of Theological Studies, 2007, the reviewer wrote of the destruction of the Temple in 587 BCE so it just depends on what dating system you use (as you know).
The importance of this "anchor" for archaeomagnetic dating is that in this period the use of radiocarbon dating is very limited in its precision, with a variation of 200 years. The detailed biblical descriptions regarding the destruction of Jerusalem enable the dating of the paleomagnetism found in the ruins to less than a year. This can then be used as an anchor to help constrain the chronology of previous and future archaeomagnetic data from the same period and help validate suggested links between the Babylonian campaign and destruction layers in other sites.