The major impacts of the Geomagnetic Storm of 1921 impact Earth. In the US, New York, which has more in the nature of telecommunications than other states, is particularly hit. The impacts were serious even for the era in which there was relatively little in the way of electronics. As a scientific paper notes:
The most spectacular (and most dangerous) examples of GIC impact were two destructive fires—the first in Sweden around 02:00 GMT on 15 May and the second in the United States around an hour later (times shown in Figure 2a by the upper pair of magenta arrows) The Swedish event occurred in a telephone exchange in the town of Karlstad, 260 km west of Stockholm. This event was widely reported around the world (e.g., Fouche et al., 1921; New York Times (NYT), 1921c; Daily Herald, 1921; Belfast Telegraph, 1921; Sunderland Daily Echo, 1921). It was also the subject of contemporary study by David Stenquist, a Swedish scientist and engineer, who had a long interest in what we would now call GIC impacts on telecommunications systems. One of his narrative reports on the event is included in his 1925 memoir on earth currents (Stenquist, 1925), and another is reproduced by Karsberg et al. (1959). They both outline how the operators at Karlstad exchange first experienced problems (equipment anomalies and faint smoke) around 01:00, followed by a period of quiet, before the main fire started around 02:00 leading to extensive equipment damage. (The scale of that damage is recorded in contemporary photographs held by several Swedish museums, as discussed in the supporting information.) Stenquist also highlighted a near‐miss incident at Ånge, some 380 km north west of Stockholm, that was simultaneous with the Karlstad fire. This experienced a threat similar to that fire, but where the initial problems were sufficient to trigger preventive measures that avoided major damage. In his later analysis of the Karlstad fire (Albinson, 2018; Engström, 1928; Stenquist, 1925), Stenquist noted that this site was vulnerable to strong GIC, because it was on the 400 km route of the major communications lines between Oslo and Stockholm, and this route was vulnerable because of its east‐west orientation. His insights into engineering design of the communications lines enabled him to estimate the geoelectric fields that created the damaging GIC. He showed that fields of at least 6 V/km were required to cause the observed melting of fuses, “tubes de fusion,” in copper wires, and that a field of 20 V/km would have caused more damage than observed (melting of fuses in iron wires). As a result he suggested that 10 V/km would be a reasonable estimate of the average geoelectric field in central Sweden at the time of the Karlstad fire. A later review of GIC impacts on wired telecommunications (Sanders, 1961) noted that in the case of the Karlstad fire, these fields would have been applied over a typical line length of 100 to 200 km, and thus concluded that the induced voltages on the lines into Karlstad would be of order 1,000 V.
The U.S. fire occurred in the village of Brewster in New York state, some 80 km north of New York city, between 03:00 and 04:00 GMT. The fire started in a switch‐board at the Brewster station of the Central New England Railroad and quickly spread to destroy the whole building (Brewster Standard, 1921a; NYT, 1921c). The first reference notes that the night operator had to evacuate the building, rousing another person asleep in the building as well as saving some valuables. There is also evidence of significant damage elsewhere in the Northeast United States caused by GIC during this storm with communications being delayed on 16 May due to the need to repair damage such as burned‐out equipment (Berkshire Eagle, 1921). One major example is that the Boston and Albany Railroad experienced damage to telegraph and telephone equipment in many places along its 250‐km route between Boston and Albany (Springfield Republican, 1921). This reference notes that the damage was most significant in the western half of the route, which passed around 100 km north of Brewster. Unfortunately, the reference does not provide any detailed information on the times when damage occurred on the Boston and Albany systems. However, it does note that other railroads in the Northeast United States (e.g., New Haven, Boston and Maine) were much less affected and attributes the vulnerability of the Boston and Albany route to its east‐west orientation. In contrast to Stenquist's analysis of the Karlstad fire, we do not appear to have any contemporary estimates of the geoelectric fields in the Northeast United States. However, there are many reports that induced voltages up to 1,000 V were measured on telegraph systems in that region (Lyman, 1921; NYT, 1921c; Telegraph and Telephone Age, 1921c). Such large voltages on telegraph lines are suggestive of geoelectric fields of order 10 V/km, as noted by Sanders (1961) in his discussion of the Karlstad fire. They are also consistent with Sanders' report that geoelectric fields of similar strength had been observed in the United States during earlier geomagnetic storms.
On this day in 1921, although I don't have a copy of it, Leslie's ran an article entitled "Is Tobacco Doomed?"
While the geomagnetic storm was ranging planet wide, a more terrestrial storm event was occurring in Maryland.
That didn't stop, however, the horse show from receiving spectators in Washington, D.C., including these ladies from the Junior League.
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