The New Age
2015 marks the 60th anniversary of the entry of humanity in the nuclear world.
Are humans really the only species willing to play with a technology they don't fully comprehend and master?
Dawn of a new age
In the first hours of July 16, 1945, the United States launched the Nuclear Age with the detonation of a 20-kiloton atomic bomb code-named ”Trinity“ at Alamogordo, New Mexico.

Shortly after, the 6 and 9 August 1945, "Littleboy" and "Fatman" where dropped on the cities of Hiroshima and Nagasaki, killing more than 125 000 persons and precipitating the end of of second world war. This is until now the only use of nuclear bombs on civilians.
A game of power
The Alamogordo test demonstrated many of the explosion's effects but a lot of the consequences of a nuclear explosion were not understood then and wouldn't be for many years.

Around 2150 nuclear tests have been realized worldwide.

The timing and chronology of the tests clearly demonstrates the impact of the Cold War with the great majority of tests occuring between the A190s and the 1980s.
Who and when?
So far, eight countries have tested nuclear weapons. Most of the tests have occured during the Cold War while the United Stated and the Russian Federation were competing for the superpower title.

Tests were and are carried out to gather information on the explosion and the impact of nuclear bombing as well as to show other countries that the technology is mastered with the hope prevent attacks on, the country.

The signature of the CTBO treaty in 1996 has drastically diminish the number of test with only a few country left realising some tests such as North Korea to name one.
How many?
The number of nuclear tests carried out varies greatly by country.

The United States holds the record in term of testing. The Russian Federation. comes second. France comes third for the number of tests with respectively 83% and 72% less tests than the United States and the Russian Federation.
Different types?
Nuclear explosions have been detonated in all environments: above ground, underground and underwater.

Atmospheric testing refers to explosions which take place in the atmosphere and detonated at heights between 40 and 540 kilometres. Their main aim was to determine the feasibility of nuclear weapons as anti-ballistic missile defense or anti-satellite weapons.
Underwater testing refers to explosions which take place underwater or close to the surface of the water. Few underwater tests have been conducted.
Underground testing means that nuclear explosions are detonated at varying depths under the surface of the earth.
at varying heights
The height of the tests that have been carried has varied greatly to measure the difference of impacts.

Bombs have been detonated on top of towers, onboard barges, suspended from balloons, on the earth's surface, underwater to depths of 600m, underground to depths of more than 2,400m and in horizontal tunnels. Test bombs have been dropped by aircraft and fired by rockets to altitudes of over 500 kilometres. With 75% off all nuclear explosions, underground tests comprises the majority of them.
So many, so powerful
The explosive yield of a nuclear weapon is the amount of energy discharged when a nuclear weapon is detonated. It is expressed usually in TNT equivalent (the standardized equivalent mass of trinitrotoluene which, if detonated, would produce the same energy discharge). In this case it is expressed in kilotons (kt—thousands of tons of TNT).

The stock
The tests have led to the development of an important nuclear arsenal whose spread is supposed to be limited by the treaty on the non-proliferation of nuclear weapons entered into force in 1970.

The world’s nuclear arsenals ballooned throughout the Cold War, from slightly more than 3,000 weapons in 1955 to over 37,000 weapons by 1965 (United States 31,000 and the Soviet Union 6,000), to 47,000 by 1975 (United States 27,000 and the Russian Federation 20,000), and over 60,000 in the late 1980s (United States 23,000 and the Soviet Union 39,000).
We're still far away from a nuclear weapons free world...


Sources:

Data used for the visualisation comes from Geoscience Australia and the Nuclear Explosion Database (NEDB)

Informations on nuclear testing have been obtained through the CTBTO website, the UN, as well as Wikipedia obviously.

Informations on nuclear weapons have been obtained through SIPRI, NRDC and our world in data.

A huge thanks to Jim Vallandingham for having developer a scroller and explained how to use it. I now need to use it well. Clearly the level of my attempt is far away from its example.

And thanks to Mike Bostock for all his d3.js examples.