Before the atomic bombs were sent to Hiroshima and Nagasaki, the world's first nuclear test explosion was conducted by the United States in the New Mexico desert. The Trinity test project was carried out on July 16, 1945, using a plutonium implosion device. Since then, from 1945 to 2017, a total of 2,056 nuclear tests were conducted by at least eight nations.

The Beginning of Bomb Spike

Nuclear bomb tests peaked in the 1950s until 1963, when the Nuclear Test Ban Treaty obliged the signatory nations to test their nuclear weapons underground. Before this agreement, the authorities exploded their atomic bombs in the open air. Over 500 blasts, mainly by the U.S. and Russia, released their contents into the atmosphere.

The tests spewed radioactive materials far and wide and caused harm to humans and wildlife, and rendered some terrestrial regions uninhabitable. The bombs also reacted with nitrogen in the air and formed new isotopes such as carbon-14. By the 1960s, the amount of carbon-14 in the atmosphere doubled and entered major landscapes, passed along the food chain to humans.

According to Walter Kutschera of the University of Vienna, every source of Earth's carbon exchange with atmospheric carbon dioxide since the late 1950s has been marked with bomb carbon-14. This sudden increase of carbon-14 in the atmosphere is known as a bomb spike or bomb pulse.

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Valuable Applications of Bomb Spike

In the mid-20th century, scientists discovered the bomb spike when the atmospheric testing of nuclear weapons stopped. However, it took decades before they realized that the increased levels of carbon-14 isotope might be useful.

Experts used to apply this isotope in determining the age of paleolithic remains or ancient texts in a process called radiocarbon dating. But since their method was based on radioactive decay, it is limited to samples over 300 years old. Younger models will not decay enough for an accurate measurement.

At the turn of the century, scientists realized the bomb spike could help them use carbon-14 isotopes more meaningfully. It allows them to date samples within the past 70-80 years by analyzing the proportions of carbon-14 of any organic substance that has exchanged carbon dioxide in the atmosphere since the tests and specifying the window in which it formed.

The carbon pool also includes individuals or objects not yet exist during the nuclear tests. For instance, a person born in the 1950s has tissues with more accumulated carbon-14 than a younger person born in the 1980s.

One of the most practical uses of bomb spikes is in forensic analysis, where crime investigators must identify the age of unidentified human bodies. They discovered that they could measure the amount of carbon-14 in a person's bones, hair, teeth, or eye lens and help them estimate their age or date of death. Additionally, it was suggested that bomb spikes could be used as markers to officially recognize the Anthropocene Epoch, a new geological era in Earth's history defined by human activity.

 

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