Nuclear explosions since 1945

The first nuclear explosion which took place on 16 July 1945 in Alamogordo (New Mexico, USA) heralded the start of an unprecedented arms race in human history which led to over two thousand nuclear explosions being detonated around the world up to the present day (see bar chart below). Although the first nuclear tests all took place in the atmosphere, even the first nuclear test was recorded by seismic stations. This series of nuclear tests reached its peak on 30.10.1961 with the nuclear explosion that took place within the earth’s atmosphere above the Arctic Ocean island of Novaya Zemlya in the former Soviet Union, which had a strength of 58,000 kilotonnes TNT equivalent.

Not least because of the radioactive fall-out, the Limited Test Ban Treaty was signed in 1963 banning nuclear weapons tests in the atmosphere, under water and in space. Nuclear testing activities therefore moved to underground locations, and seismology therefore plays a key role in monitoring these tests. The global seismic networks currently being operated are able to locate underground nuclear tests taking place anywhere in the world with a strength of at least 1 kt TNT equivalent, and to identify them as coming from a nuclear explosion. Nuclear tests with much smaller explosive forces can also be identified in many regions around the world thanks to denser regional station networks.

The most recent nuclear test was conducted by the Democratic People’s Republic of Korea on 25 May 2009.

The world map shows the location of the epicentres of all known nuclear explosions. The nuclear explosion list provides information on the most important test parameters for all of the nuclear tests registered in Germany by the Gräfenberg array (GRF) and the GERES array.

Topographic map of the world with the epicenters of all known nuclear explosions since 1945 (red dots) Source: BGR

Number of nuclear tests per year

The bar chart showing the number of nuclear tests carried out per year since 1945 by different countries shows a clear decrease in the number of tests conducted since the Comprehensive Test Ban Treaty (CTBT) was signed in September 1966. The “gap” in test activities after 1958 reflects the test moratorium agreed by a number of countries for this period.

Bar chart showing the number of nuclear tests per year for the period 1945-2009 Source: BGR