Rapidly changing geomagnetic field variations constitute a natural hazard, for\ud example to grounded power grids and pipeline networks. To understand this hazard\ud we have continuous magnetic measurements across the world for typically less than\ud 100 years. Much of the older data is also in analogue form, or is only available digitally\ud as hourly or daily magnetic indices or mean levels. So it may not yet be clear what the\ud true extremes in geomagnetic variation are, particularly on time scales - seconds to\ud minutes - that are relevant for estimating the hazard to technological systems.\ud \ud We therefore use a number of decades of one minute samples of magnetic data from\ud observatories in Europe, together with the technique of 'extreme value statistics', to\ud explore estimated maxima in field variations in the horizontal strength and in the\ud declination of the field. These maxima are expressed, for example, in terms of the\ud variations that might be observed on time scales of 100 and 200 years. We also\ud examine the extremes in the one-minute rate of change of these field components on\ud similar time scales.\ud \ud The results should find application in hazard assessment and navigation applications
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.