Nuclear Blasts in Mississippi

Stephen Cresswell

At 10:00 a.m. on October 22, 1964, the United States government detonated an underground nuclear device in Lamar County, in south Mississippi.  Residents there felt three separate shocks, and watched as the soil rose and behaved like ocean waves.  Hunting dogs howled in terror, and two miles from the test site the blast shook pecans off the pecan trees.  This nuclear test, and the one that followed two years later at the same Mississippi site, were the only nuclear explosions on U.S. soil east of the Rocky Mountain states.

Atomic bombs were in the news in October 1964.  Only one week before the Mississippi nuclear test, newspapers had reported that Communist China had detonated its first atomic bomb.  For residents in Lamar County, however, no news story was watched more closely than the plans for nuclear testing in Mississippi.

Project Dribble

A number of nuclear testing experts said it was not a good idea to prohibit underground testing, because some nations might cheat by secretly testing nuclear weapons underground.  In most cases, seismographs (the device used to measure earthquakes) could detect underground nuclear tests.  The United States wanted to know more about underground testing and how it could be detected, and designed Project Dribble, which included the two Mississippi detonations, to investigate the possibility that cheating nations could hide their underground tests in some way.

Nuclear scientists investigated several potential test sites in Mississippi, but finally selected a site just north of Baxterville in Lamar County, about 28 miles southwest of Hattiesburg.  Geologically, the area was called the Tatum Salt Dome, a vast supply of dense salt located about 1,000 feet below ground level. Salt domes deep beneath the surface of south central Mississippi are the dried remains of a sea that covered much of the state in the Mesozoic Era.  The plan was to detonate one nuclear bomb about 2,700 feet down, in solid salt.  This would be the 1964 blast, code-named Project Salmon.  It was believed Project Salmon would blast a huge cavity in the salt.  Then the second blast, Project Sterling, would involve detonating a smaller nuclear bomb inside the cavity left in the salt by Project Salmon.  Scientists believed that because the bomb would be detonated in a cavity rather than in solid rock, the shock waves would be muffled and the test might not be detectable by seismographs and other measuring devices.

So in 1964 officials of the Atomic Energy Commission came to Mississippi and began preparing the Tatum Salt Dome site for Project Salmon.  A hundred Lamar County residents found work at the site, primarily driving trucks and heavy equipment, or providing food for the project employees.  The nuclear test was scheduled for September 22, 1964, but the wind direction was not right until October 22.  On that date about 400 residents were evacuated from the area, and were paid $10 per adult and $5 per child for their inconvenience.  The zone from which citizens were evacuated stretched five miles downwind of ground zero, and about half that distance in directions that were not downwind of the test. Click here to see the Mississippi segment from the Peter Kuran film “Atomic Journeys.” (YouTube site accessed July 2008.)

Most residents later reported that the shock of the explosion was much stronger than they had been led to believe.  The editor of the Hattiesburg American, although almost thirty miles away, reported that he felt the newspaper building sway for nearly three minutes.  At the test site, creeks ran black with silt-laden water, and by seven days after the blast, more than 400 nearby residents had filed damage claims with the government, reporting that their homes had been damaged or that their water wells had gone dry.

Horace Burge lived about two miles from the site of the explosion, and returned home to his three-room house to discover considerable damage caused by the blast.  The fireplace and chimney were badly damaged, and bricks littered his living room.  Broken dishes and jars were all over his kitchen floor, and the shelves fell down inside his refrigerator and broke several glass containers.  His electric stove was covered with ash and pieces of concrete.  The pipes under his kitchen sink had burst, leading to flooding inside the house.

Within days, the United States government began reimbursing local residents for the damage done to their homes.  After the blast, reporters from the Hattiesburg American interviewed many local residents who said they didn’t want this nuclear testing to be done in their neighborhoods, but who added that there was nothing they could do about it. In an editorial, the Hattiesburg American lectured its readers that such tests were necessary for the future security of the United States.

After seismic analysis, the government scientists reported that Project Salmon had been a success, with the bomb delivering the same force as 5,000 tons of TNT.  The Project Salmon blast was about one-third as powerful as the bomb that destroyed Hiroshima in 1945.  The bomb blasted a void in the salt as predicted, a spherical cavity that was about 110 feet in diameter.

The Project Sterling blast, on December 3, 1966, was considerably weaker than the blast two years earlier, as it was intended to be.  Instead of the force of 5,000 tons of TNT that Project Salmon had developed, Project Sterling’s bomb had the force of 350 tons of TNT.  Observers two miles away from the blast reported they barely felt a bump.  Like Project Salmon, Project Sterling was labeled a success.  Because it was detonated in a cavity in the salt, its force, as measured by seismographs, was about 100 times weaker than would have been expected with the same sized bomb placed in solid rock or salt.  Thus U.S. government officials reported that Mississippi’s two nuclear blasts, as a part of Project Dribble, helped prove that in fact the seismic effect of a nuclear blast could be greatly reduced if such a blast were set off in a large cave.  This suggested it might be possible for a nation to cheat on a future nuclear test ban by hiding a nuclear test.  It also helped teach atomic scientists how to detect and measure such hidden blasts.

Though Mississippi’s part in nuclear testing was over by 1966, the Tatum Salt Dome site did see two additional tests by the Atomic Energy Commission as a part of Project Miracle Play. Project Miracle Play was similar to Project Dribble in that it too was designed to detect underground testing, but this time the two blasts were conventional bombs instead of nuclear.  Mississippi’s two explosions in Project Miracle Play in 1969 and 1970 were fueled by a mixture of oxygen and methane.