Mystery Geomagnetic Event Observed Around the World

Craig Young
Director, Crystal Lake Observatory

The geomagnetic observatory at Munich Germany, a member of the Crystal Lake Observatory worldwide amateur online Geomagnetic Observatory Network (GON), captured the magnetic disturbance shown in Fig. 1 on 8 October 2005 at 1900 UTC.

The vertical scale in Fig. 1 is approximately 25 nT/div, which makes the amplitude of the event about 75 nT, with a duration of slightly longer than one hour.

Figure 1. Magnetic disturbance captured by the the GON observatory at Munich, Germany, on 8 October 2005 at 1900 UTC.

What makes the event in Fig. 1 so unusual is that it happened again 24 hours later. Figure 2 shows the second event.

Figure 2. A second magnetic disturbance captured by the the GON observatory at Munich, Germany, 24 hours after the one in Fig. 1.

The event in Fig. 2 occurred at the same exact time and has the same duration and pulse shape but a smaller amplitude. Notice the small dip in the signal prior to the main event. Also, notice the small variation in the signal at exactly 2000 UTC. These two features show up on both days.

Both events in Figs. 1 and 2 were also recorded by a GON observatory England. The data for 8 October are shown in Fig.3.

Figure 3. Magnetic disturbance captured by the the GON observatory in England on 8 October 2005. Compare this data with Fig. 1.

The data in Fig. 3 are phase inverted due to a difference in the orientation of the magnetic sensor. The event occurred at the exact same instant and duration as the one recorded in Fig. 1. Notice the amplitude of the event recorded at this observatory is more than 100 nT, compared to the 75 nT at the Munich observatory (Fig. 1).

As shown in Fig. 4, the 8 October event was also captured by the GON observatory in Mobile, Alabama.

Figure 4. Magnetic disturbance captured by the the GON observatory in Mobile, Alabama, on 8 October 2005. Compare this data with Figs. 1 and 3.

As shown in Fig. 5, half way around the world the event was also recorded by the GON observatory in New Zealand.

Figure 5. Magnetic disturbance captured by the the GON observatory in New Zealand on 8 October 2005. Compare this data with Figs. 1, 3 and 4.

The event was not detected by any of the observatories on 10 October. But on 26 October the European GON observatories recorded another incident of a geomagnetic disturbance which repeated itself exactly 24 hours later. The two days of data resemble the data shown here and are graphically shown on the GON web page. As with the events described here, the second event occurred exactly 24 hours after the first. The phase, shape and duration of the pulse was almost identical to the two events on 8 and 9 October.

Various people are investigating this, but, as of now, there is no known explanation. The event was recorded by both GON and INTERMAG observatories in Europe, but was not seen in the U.S. or New Zealand.

We can deduce from the various data that the events on 8 and 9 October had a global effect on the earth's magnetic field. There are two significant facts that suggest the source of the event was artificial and not natural:

1. The event repeats itself exactly 24 hours later.

2. The shape and duration of the pulse is the same on both days.

The source of the event remains a mystery and we are calling on the scientific community to assist us in identifying it. If you have some ideas of what this may be, or would like to have access to the raw data for further analysis, please contact us at clo@ihug.co.nz

Becoming a GON Observer

This is but one of the many interesting events that we see on the network each day. We may think that the earth's geomagnetic field is constant, but that is far from the truth. Most of the large events captured on GON are a result of solar activity, for example, flares, shifts in the Interplanetary Magnetic Field, and coronal hole streams. These are all global in nature, seen by all of the observatories on the GON network.

The most interesting events are those recorded by observatories in a particular region or local area. This is largely unexplored territory ripe with opportunities for amateur scientists and investigators. These "local" events may be due to weather systems, movements of the earth underground, atmospheric effects or intense emissions by electronic equipment.

GON real time data are freely available on the Internet and can be used by anyone for research, science fair projects, or just casual observing. The GON instruments have nearly the same sensitivity as the professional scientific observatory instruments, making the data especially useful for serious amateur scientific research.

For those who want to set up their own GON observatory and contribute to the worldwide network of data, the cost is minimal and installation is easy. Observatories can be established in rural or urban locations and operated in rain or sunshine 24 hours a day.

More information about GON, and the various research projects underway can be found at our web site: http://www.advancedtrack.net/webs/clo/

Note to Readers: As described in this article by Craig Young, amateur scientists can make a significant contribution to monitoring the earth's geomagnetic activity. Readers are encouraged to visit the GON homepage for extensive information about how to become an observer. The Citizen Scientist hopes to publish future articles and reports about findings from the GON. Editor.