99 years ago this week in May, people all over the world woke up and were shocked by some unusual headlines. “The telegraph service has been defeated, the Comet is not to blame,” the Los Angeles Times said on May 15, 1921. “Electrical disturbances are the worst ever known, “the Chicago Daily Tribune said.
At that time they did not know this, but newspapers covered the biggest solar storm of the 20th century. Since then, nothing like this has happened.
It all started on May 12, 1921, when the giant sunspot AR1842, crossing the sun during the sunset phase of the solar cycle 15, began to flash. One explosion after another threw coronal mass ejections (CMS) directly to the Earth.
Over the next 3 days, a powerful geomagnetic storm shook Earth’s magnetic field. Scientists around the world were surprised when their magnetometers suddenly got out of hand, pens in strip card recorders were uselessly attached to the top of the paper.
And then the fire started. Around 02:00 Moscow time on May 15, the telegraph exchange in Sweden caught fire. About an hour later, the same thing happened across the Atlantic in the village of Brewster, New York. Flames swept the switchboard at the Brewster station of the New England Central Railroad and quickly spread to destroy the entire building. This fire, as well as another one at about the same time at the railway control tower near New York Central Station, is the reason this event is sometimes called the “New York Railroad Super-Storm.”
What caused the fire? Electric currents caused by geomagnetic activity passed through telephone and telegraph lines, heating them to a burning point. Strong currents disrupted telegraph systems in Australia, Brazil, Denmark, France, Japan, New Zealand, Norway, Sweden, the UK and the USA. The Ottawa Journal reported that many long distance telephone lines in New Brunswick were burned due to a storm. On some telegraph lines in the USA, the voltage reached 1000 V.
During the peak of the storm on May 15, southern cities such as Los Angeles and Atlanta felt like Fairbanks, with northern lights dancing overhead, while telegraph lines crackled with geomagnetic currents. Auroras were spotted in the USA right up to Texas, while in the Pacific Ocean red auroras were spotted from Samoa and Tonga and ships at sea crossing the equator.
What would happen if such a storm happened today?
Scientists have long discussed this issue. As a result of research, it was found that the storm peaked on May 15: its intensity was comparable to the intensity of the Carrington event of 1859.
This result disproves the generally accepted point of view. Space weather researchers believed the Carrington Event was the strongest solar storm in recorded history. Now we know that the May Storm of 1921 was about as strong.
If the May Storm of 1921 hit today, it would at least lead to a power outage, profound changes in satellite orbits, and the loss of radio technology such as GPS. GPS malfunction can significantly affect the operation of logistics and emergency services.
This is something to think about on the 99th anniversary of a 100-year storm ….