Alexander von Humboldt's charts of the Earth's magnetic field: an assessment based on modern models

摘要

The 19th century witnessed a resurgence of interest in Earth's magneticfield. Both observational and theoretical aspects were involved, and one ofthe emblematic figures of this period was Alexander von Humboldt. Throughouta long life he maintained a strong interest in a broad area of subjects,however, here we are interested in his role in geomagnetism, andparticularly in his pioneering contributions to charting the geomagneticfield. Alexander von Humboldt efforts in measuring and charting the Earth'smagnetic field are recounted and the maps of declination, inclination andtotal intensity he had prepared are compared, favorably, with maps for thesame epoch based on a modern model of the geomagnetic field, gufm1. This modernassessment of the accuracy of von Humboldt's geomagnetic charts illustratesthe importance of his work, being also our homage to the 150th anniversaryof the death of Alexander von Humboldt.