Analysis of recently classified US military documents confirms the suspicion that, during the final stages of the Vietnam War, strong solar storms caused dozens of sea mines to explode. This is a real warning from the Sun's potential to disrupt our technological activities in unexpected ways.
As part of Operation Pocket Money, the US Navy planted a series of Destructor sea mines near a strategic port off the coast of North Vietnam. A few weeks later, on August 4, 1972, crew members on a US 77 Air Force plane suddenly observed an explosive explosion south of Hai Phong.
Overall, around 20 to 30 explosions are documented in just 30 seconds. 25 to 30 other patches of muddy water are also observed, indicating further explosions.
That is a strange event, because there is no reason why mines should go. Almost immediately, US officials began to contemplate extreme solar activity as the cause, as expressed in the recently opened US Navy document.
New research was published last month at Space Weather, a publication of the American Geophysical Union, agreed with this 46-year assessment, while giving new details about this very bad solar storm, which disrupts more than just sea mines.
The study's author, led by Delores Knipp of the University of Colorado and Brian Fraser of the National Center for Atmospheric Research, Boulder, said historical events should function as call to action.
Exploding bombs are magnetic sea mines, weapons originating from the First World War. When a ship passes above, the mine feels a change in the density of the magnetic field, triggering an explosion. Within days of the August 1972 incident, US military officials began to wonder whether solar activity might be responsible for an unexpected mine explosion.
As RMIT's senior lecturer, Brett Carter reported Conversation, scientists in the 1970s were already aware of the Sun's potential to trigger changes in magnetic fields – they were just not sure if it was strong enough to push mines into detonation.
As part of its investigation, the US military sent officials to the Space Environment Laboratory on the National Oceanographic and Atmospheric Agency (NOAA) near Boulder, Colorado. After consulting with scientists, the researchers concluded with a "high probability level" that solar storm activity was responsible for the destruction of magnetic mines that seemed spontaneous.
Buried for almost 50 years, the currently unclassified documents were re-analyzed by the Knipp and Fraser teams. Indeed, August 1972 experienced an intense period of solar activity – some of the strongest ever recorded.
Between August 2 and 4, the sunspot area of MR 11976 issued a series of solar flares, the release of coronal masses, and clouds of charged particles (called "plasma drivers" in the 1970s). The release of the coronal mass that causes sea mines to explode reaches the Earth in only 14.6 hours – a record for such events (usually requiring one or two full days for these electromagnetic pulses to reach our planet's geomagnetic field and produce magnetic storms).
The reason for speed, the authors say, is that the previous two beats from the Sun on August 2 cleared the way to our planet, producing "ultra-fast" mass ejection on August 4th. In addition to mine explosions, solar storms cause electrical disturbances and telegraph power outages, as Carter reports.
"Based on the evidence presented, we convey that the events of August 4, 1972 were Carrington class hurricanes," the authors wrote in the study. "The transit time for this event is shorter than the Carrington event."
With the Carrington event, the researchers refer to the strong geomagnetic solar storm that occurred in 1859. It remains one of the strongest solar storms recorded. Similar events today will cause severe disruption, knock down satellites, electricity networks, and, as shown by new studies, technologies that we don't even know are vulnerable.
In closing, the study authors said 1972 hurricanes were worthy of further examination and suggested that other researchers to collect their archive information together in an effort to learn more. No doubt, the more dependent we are on technology, the more vulnerable we become to this extreme solar event. Knowing as much as possible about geomagnetic storms can prevent a lot of sadness.[Space Weather via The Conversation]