Amerigeddon: Grid-down EMP scenario goes mainstream ( Archived) (29)

On July 9, 1962, at 09:00:09 Coordinated Universal Time (July 8, Honolulu time, at nine seconds after 11 p.m.), the Starfish Prime test was successfully detonated at an altitude of 400 kilometres (250 mi). The coordinates of the detonation were 16°28'N 169°38'WCoordinates: 16°28'N 169°38'W. The actual weapon yield came very close to the design yield, which various sources have set at different values in the range of 1.4 to 1.45 megatons (6.0 PJ). The nuclear warhead detonated 13 minutes and 41 seconds after liftoff of the Thor missile from Johnston Island.

Starfish Prime caused an electromagnetic pulse (EMP), which was far larger than expected, so much larger that it drove much of the instrumentation off scale, causing great difficulty in getting accurate measurements. The Starfish Prime electromagnetic pulse also made those effects known to the public by causing electrical damage in Hawaii, about 1,445 kilometres (898 mi) away from the detonation point, knocking out about 300 streetlights, setting off numerous burglar alarms and damaging a telephone company microwave link. The EMP damage to the microwave link shut down telephone calls from Kauai to the other Hawaiian islands.

A total of 27 small rockets were launched from Johnston Island to obtain experimental data from the Starfish Prime detonation. In addition, a large number of rocket-borne instruments were launched from a firing area at Barking Sands, Kauai in the Hawaiian Islands.

A very large number of United States military ships and aircraft were operating in support of Starfish Prime in the Johnston Island area and across the nearby North Pacific region.

A few military ships and aircraft were also positioned in the region of the South Pacific Ocean near the Samoan Islands. This location was at the southern end of the magnetic field line of the Earth's magnetic field from the position of the nuclear detonation, an area known as the "southern conjugate region" for the test. In addition, an uninvited scientific expeditionary ship from the Soviet Union was stationed near Johnston Island for the test, and another Soviet scientific expeditionary ship was located in the southern conjugate region near the Samoan Islands.

After the Starfish Prime detonation, bright auroras were observed in the detonation area as well as in the southern conjugate region on the other side of the equator from the detonation. According to one of the first technical reports:

"The visible phenomena due to the burst were widespread and quite intense; a very large area of the Pacific was illuminated by the auroral phenomena, from far south of the south magnetic conjugate area (Tongatapu) through the burst area to far north of the north conjugate area (French Frigate Shoals)... At twilight after the burst, resonant scattering of light from lithium and other debris was observed at Johnston and French Frigate Shoals for many days confirming the long time presence of debris in the atmosphere. An interesting side effect was that the Royal New Zealand Air Force was aided in anti-submarine maneuvers by the light from the bomb."