Pacific Proving Grounds

nuclear test sites, Pacific Ocean

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 22, 2026

Quick Summary

The Pacific Proving Grounds were a series of nuclear weapons test sites used by the United States in the Pacific Ocean between 1946 and 1958. These tests were primarily conducted on the Marshall Islands, specifically at Bikini and Enewetak atolls.1

A total of 67 nuclear tests were carried out, including the first test of a thermonuclear bomb in 1952. The most powerful test, Castle Bravo in 1954, yielded 15 megatons, significantly more than anticipated, and scattered radioactive debris over a wide area. These tests contaminated the atolls with radiation, rendering them uninhabitable. The U.S. has since paid compensation to the Marshall Islanders for the devastating effects of these tests.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

3 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

atomic bomb
Development and proliferation of atomic bombs
…of atomic bombs in the Pacific Proving Grounds in the Marshall Islands (especially Bikini and Enewetak atolls) and in Nevada. In subsequent years, the Soviet Union (1949), Great Britain (1952), France (1960), China (1964), India (1974),
Read More
…of atomic bombs in the Pacific Proving Grounds in the Marshall Islands (especially Bikini and Enewetak atolls) and in Nevada. In subsequent years, the Soviet Union (1949), Great Britain (1952), France (1960), China (1964), India (1974),
Read More