ground zero

The Hiroshima Prefectural Industrial Promotion Hall was only 150 m from the hypocenter, or ground zero, of the atomic bomb explosion over Hiroshima.

The term ground zero (sometimes also known as surface zero^[1] as distinguished from zero point^[2]) may be used to describe the point on the earth's surface where an explosion occurs. In the case of an explosion above the ground, ground zero refers to the point on the ground directly below an explosion (see hypocenter).

The term has often been associated with nuclear explosions and other large bombs, but is also used in relation to earthquakes, epidemics and other disasters to mark the point of the most severe damage or destruction. The term is often re-used for disasters that have a geographic or conceptual epicenter.

History of term

The origins of the term "ground zero" began with the Manhattan Project and the bombing of Japan. The Oxford English Dictionary, citing the use of the term in a 1946 New York Times report on the destroyed city of Hiroshima, defines "ground zero" as "that part of the ground situated immediately under an exploding bomb, especially an atomic one."

The term was military slang—used at the Trinity site where the weapon tower for the first nuclear weapon was at "point zero"—and moved into general use very shortly after the end of World War II.

Hiroshima and Nagasaki

Relating to a specific event, the term was first used to refer to the devastation caused by the atomic bombings of Hiroshima and Nagasaki.^[3]

Panoramic view of the monument marking the hypocentre, or ground zero, of the atomic bomb explosion over Nagasaki.

The Pentagon

Ground Zero Cafe in the Pentagon's center courtyard.

The Pentagon, the headquarters of the U.S. Department of Defense in Arlington, Virginia was thought of as the most likely target of a nuclear missile strike during the Cold War. The open space in the center is informally known as ground zero, and a snack bar located at the center of this plaza is named the "Ground Zero Cafe."

World Trade Center

World Trade Center site.

The term was also used to describe the site of the World Trade Center in New York City, which was destroyed in the September 11, 2001 attacks. The adoption of this term by the mainstream North American media with reference to the September 11th attacks began as early as 7:47 p.m. (EDT) on that day, when CBS News reporter Jim Axelrod said,

Rescue workers also used the phrase "The Pile", referring to the pile of rubble that was left after the buildings collapsed.^[5]

References