Illustration above is from the United States Defense Threat Reduction Agency about the E1 component of nuclear electromagnetic pulse. The source region is the region of the upper atmosphere where gamma radiation from the weapon knocks out electrons from atoms in the atmosphere, which travel in a generally downward direction at roughly 94 percent of the speed of light, and are acted upon by the Earth's magnetic field to generate a powerful burst of electromagnetic energy. This source region, where the EMP is actually generated, is a very large area in the middle of the stratosphere. (In the map on the right side of the illustration, HOB is the height of the nuclear burst in kilometers.)
In testimony before the United States Congress House Armed Services Committee on October 7, 1999, the eminent physicist Dr. Lowell Wood, in talking about Starfish Prime and the related EMP-producing nuclear tests in 1962, stated,
"Most fortunately, these tests took place over Johnston Island in the mid-Pacific rather than the Nevada Test Site, or electromagnetic pulse would still be indelibly imprinted in the minds of the citizenry of the western U.S., as well as in the history books. As it was, significant damage was done to both civilian and military electrical systems throughout the Hawaiian Islands, over 800 miles away from ground zero. The origin and nature of this damage was successfully obscured at the time -- aided by its mysterious character and the essentially incredible truth."
The Starfish Prime test (a part of Operation Fishbowl) was detonated at 59 minutes and 51 seconds before midnight, Honolulu time, on the night of July 8, 1962. (Official documents give the date as July 9 because that was the date at the Greenwich meridian, known as Coordinated Universal Time.) It was considered an important scientific event, and was monitored by hundreds of scientific instruments across the Pacific and in space. Although an electromagnetic pulse was expected, an accurate measurement of the size of the pulse could not be made immediately because a respected physicist had made calculations that hugely underestimated the size of the EMP. Consequently, the amplitude of the pulse went completely off the scale at which the scientific instruments near the test site had been set. Although many of the scientific instruments malfunctioned, a large amount of data was obtained and analyzed in the following months.
When the 1.44 megaton W49 thermonuclear warhead detonated at an altitude of 250 miles (400 km), it made no sound. There was a very brief and very bright white flash in the sky that witnesses described as being like a huge flashbulb going off in the sky. The flash could be easily seen even through the overcast sky at Kwajalein Island, about 2000 km. to the west-southwest.
After the white flash, the entire sky glowed green over the mid-Pacific for a second, then a bright red glow formed at "sky zero" where the detonation had occurred. Long-range radio communication was disrupted a period of time ranging from a few minutes to several hours after the detonation (depending upon the frequency and the radio path being used).
In a phenomenon unrelated to the EMP, the radiation cloud from the Starfish Prime test subsequently destroyed at least 5 United States satellites and one Soviet satellite. The most well-known of the satellites was Telstar I, the world's first active communications satellite. Telstar I was launched the day after the Starfish Prime test, and it did make a dramatic demonstration of the value of active communication satellites with live trans-Atlantic television broadcasts before it orbited through radiation produced by Starfish Prime (and other subsequent nuclear tests in space). Telstar I was damaged by the radiation cloud, and failed completely a few months later.
read more at link... http://www.futurescience.com/emp.html and http://www.futurescience.com/emp/fishbowl.html
In testimony before the United States Congress House Armed Services Committee on October 7, 1999, the eminent physicist Dr. Lowell Wood, in talking about Starfish Prime and the related EMP-producing nuclear tests in 1962, stated,
"Most fortunately, these tests took place over Johnston Island in the mid-Pacific rather than the Nevada Test Site, or electromagnetic pulse would still be indelibly imprinted in the minds of the citizenry of the western U.S., as well as in the history books. As it was, significant damage was done to both civilian and military electrical systems throughout the Hawaiian Islands, over 800 miles away from ground zero. The origin and nature of this damage was successfully obscured at the time -- aided by its mysterious character and the essentially incredible truth."
The Starfish Prime test (a part of Operation Fishbowl) was detonated at 59 minutes and 51 seconds before midnight, Honolulu time, on the night of July 8, 1962. (Official documents give the date as July 9 because that was the date at the Greenwich meridian, known as Coordinated Universal Time.) It was considered an important scientific event, and was monitored by hundreds of scientific instruments across the Pacific and in space. Although an electromagnetic pulse was expected, an accurate measurement of the size of the pulse could not be made immediately because a respected physicist had made calculations that hugely underestimated the size of the EMP. Consequently, the amplitude of the pulse went completely off the scale at which the scientific instruments near the test site had been set. Although many of the scientific instruments malfunctioned, a large amount of data was obtained and analyzed in the following months.
When the 1.44 megaton W49 thermonuclear warhead detonated at an altitude of 250 miles (400 km), it made no sound. There was a very brief and very bright white flash in the sky that witnesses described as being like a huge flashbulb going off in the sky. The flash could be easily seen even through the overcast sky at Kwajalein Island, about 2000 km. to the west-southwest.
After the white flash, the entire sky glowed green over the mid-Pacific for a second, then a bright red glow formed at "sky zero" where the detonation had occurred. Long-range radio communication was disrupted a period of time ranging from a few minutes to several hours after the detonation (depending upon the frequency and the radio path being used).
In a phenomenon unrelated to the EMP, the radiation cloud from the Starfish Prime test subsequently destroyed at least 5 United States satellites and one Soviet satellite. The most well-known of the satellites was Telstar I, the world's first active communications satellite. Telstar I was launched the day after the Starfish Prime test, and it did make a dramatic demonstration of the value of active communication satellites with live trans-Atlantic television broadcasts before it orbited through radiation produced by Starfish Prime (and other subsequent nuclear tests in space). Telstar I was damaged by the radiation cloud, and failed completely a few months later.
read more at link... http://www.futurescience.com/emp.html and http://www.futurescience.com/emp/fishbowl.html
