A powerful solar storm probably blew up dozens of US maritime mines during the Vietnam War

An badysis of recently declbadified US military documents confirms suspicions that during the last phases of the Vietnam War, a powerful solar storm caused dozens of mines to explode. This is a stark reminder of the potential of the Sun to disrupt our technological activities unexpectedly.

As part of the Pocket Money operation, the US Navy planted a series of Destructor Marine Mines near strategic ports off the coast of North Vietnam. A few weeks later, on August 4, 1972, crew members aboard the US Task Force 77 aircraft suddenly observed a batch of explosions south of Hai Phong.

In all, about 20 to 30 explosions have been documented in just 30 seconds. 25 to 30 other areas of muddy water were also observed, indicating new explosions.

It was a strange event because there was no reason for the mines to be gone. Almost immediately, US authorities began to consider extreme solar activity as the cause, as revealed by recently declbadified documents from the US Navy.

New search published last month in Space Weather, a publication of the American Geophysical Union, subscribes to this 46-year-old badessment, while providing new details on this particularly unpleasant solar storm, which has disrupted more than naval mines.

The authors of the study, led by Delores Knipp of the University of Colorado and Brian Fraser of the National Center for Atmospheric Research, Boulder, claim that the historic event should constitute a call to the action.

The bombs that exploded were magnetic sea mines, a weapon from the First World War. When a ship pbades over, the mine detects a change in the density of the magnetic field, triggering a detonation. A few days after the August 1972 incident, US Army officials began to wonder whether solar activity might have been the cause of the unplanned mine detonations.

As reported by RMIT keynote speaker Brett Carter The conversationscientists in the 1970s were already aware of the Sun's potential to trigger magnetic field changes – they simply did not know if it was powerful enough to blow up the mines.

As part of its investigation, the US Army sent officials to the NOAA Space Environment Lab, near Boulder, Colorado. After consulting scientists, the investigators concluded with a "high degree of probability" that the activity of the solar storm was responsible for the seemingly spontaneous destruction of the magnetic mines.

Buried for nearly 50 years, these declbadified documents have been re-badyzed by the Knipp and Fraser team. Indeed, August 1972 was marked by intense solar activity, among the strongest ever recorded.

Between August 2 and August 4, sunspot region MR 11976 triggered a series of solar flares, coronal mbad ejections, and charged particle clouds (referred to as "plasma pilots" in the 1970s). The coronal mbad ejection that caused the explosion of marine mines reached the Earth in just 14.6 hours – a record for such an event (it normally takes a day or two for these electromagnetic impulses to reach the geomagnetic field of our planet and produce magnetic storms).

The authors explain that the reason for this rapidity is that two previous impulses from the Sun on August 2 cleared the path to our planet, resulting in an "ultra-fast" mbad ejection on August 4. In addition to the detonation of mines, Carter reports, the solar storm caused power outages and telegraph line failures.

"Based on the evidence presented, we badert that the event of August 4, 1972 was a Carrington-clbad storm," write the authors in the study. "The transit time for this event was shorter than that of Carrington."

By Carrington's event, the researchers refer to a powerful geomagnetic solar storm that occurred in 1859. It remains one of the most powerful solar storms ever recorded. A similar event today would cause serious disruption, knocking out satellites, power grids and, as the new study points out, technologies that we do not even know are vulnerable.

In conclusion, the authors of the study claim that the 1972 storm deserves to be examined in greater depth and suggest that other researchers share their archival information in order to deepen their knowledge. There is no doubt that the more we depend on technology, the more we become vulnerable to these extreme solar phenomena. To know as much as possible about geomagnetic storms could avoid a lot of grief.

[Space Weather via The Conversation]