Kaboomly / Bomb map

Nuclear Bomb Map

A nuclear bomb map puts the estimated effects of a single explosion onto real streets and skylines. Seeing a ring cross a familiar neighborhood gives a sense of scale that a list of distances cannot.

The map above is the same Kaboomly nuke simulator that runs on the homepage. This guide covers how to move around it, what the colors mean, and how to share a scenario. All figures are rough estimates for education, based on Glasstone and Dolan's The Effects of Nuclear Weapons (1977).

Exploring cities

The map opens on a slowly turning globe. There are three ways to choose a place:

Search. Start typing a city name. The search uses a built-in list of 1,210 large cities, so it works without sending your query anywhere.
City buttons. A few well-known cities are one tap away.
Click the globe. Any point on Earth works, including places that are not in the city list.

The camera then flies down toward the city and tilts to show it in perspective. Drag to pan, scroll or pinch to zoom, and right-drag (or use two fingers on a touch screen) to rotate and tilt the view. Click the map to move ground zero, or choose Pick another city to go back to the globe.

Choosing a weapon and burst type

The weapon bar at the bottom of the screen offers historical yields as presets. They are there to give a sense of the range of sizes, from the first bombs of 1945 to the largest test ever conducted:

Little Boy, 15 kt: Hiroshima, 1945.
Fat Man, 21 kt: Nagasaki, 1945.
W76, 100 kt: US submarine-launched warhead.
W88, 475 kt: US submarine-launched warhead.
B83, 1.2 Mt: US gravity bomb, up to 1.2 Mt.
Castle Bravo, 15 Mt: US test, Bikini Atoll, 1954.
Tsar Bomba, 50 Mt: Soviet test, Novaya Zemlya, 1961.

The Custom button accepts any yield from 0.01 kt to 100 Mt. Next to the weapons you choose Airburst or Surface. An airburst explodes at one fixed height, scaled from the Hiroshima explosion; a surface burst explodes at ground level. The nuclear blast radius page compares the two.

Reading the 3D building colors

For smaller yields the camera stays close enough to show buildings in 3D. When the blast wave passes, each building briefly flashes and then takes a color based on its distance from ground zero:

Red: inside the 5 psi ring, where most houses and other residential buildings would collapse or be badly damaged.
Amber: between the 5 psi and 1 psi rings, where windows break and damage is lighter.
Dark gray: beyond the 1 psi ring.

The colors follow the rings and nothing else. They do not account for how strongly a particular building is built, and they ignore the way nearby buildings and hills shield one another. Read them as a way to see the size of each zone, not as a verdict on any single building.

For larger yields the 5 psi ring stretches across many kilometers and the buildings become too small to read. The map then shows the effect rings on their own and pulls the camera back to fit them.

Reading the rings and the results panel

Each ring on the ground marks one effect: the fireball, 20 psi, 5 psi, and 1 psi of blast overpressure, a 50% chance of third-degree burns on bare skin, and a 500 rem dose of initial radiation. The blast radius guide explains each one and lists them for every preset.

After the detonation sequence, the results panel shows the radius of each ring. Tap the unit button to switch between kilometers and miles. If a scenario goes beyond the range of the source charts, for example a yield above 10 megatons, an Accuracy notes section explains which numbers are extrapolated.

Ideas for exploring

Pick your own city and try the smallest and largest presets to see how differently the rings grow.
Run the same yield as an airburst and then as a surface burst, and watch which rings grow and which shrink.
Place ground zero near a coastline or a range of hills and notice that the rings stay perfect circles. The model ignores water and terrain, which is one of its main simplifications.
Try the Hiroshima and Nagasaki presets, then read about the historical events in a museum or library source to connect the map with what happened.

After a detonation, the Share button copies a link to your clipboard. The link stores the latitude and longitude of ground zero, the yield, and the burst type. Anyone who opens it skips the globe, flies straight to that spot, and sees the same sequence. They can skip the animation with a click or the Esc key.

The link holds the exact coordinates you picked. If you placed ground zero on your own street, keep that in mind before posting it publicly.

Map data

Map tiles and building footprints come from OpenFreeMap, built on OpenStreetMap data. The city list comes from GeoNames (CC BY 4.0). OpenStreetMap is mapped by volunteers, so building coverage and heights vary: some cities are mapped in great detail, others show only a few footprints. Full attribution is on the How It Works page.

Ready to try it? Scroll up to the map, or open the full-screen nuke simulator on the homepage.

Frequently asked questions

How do I choose a location on the nuclear bomb map?

Search for a city by name, tap one of the city buttons, or click anywhere on the globe. After the camera arrives, you can click the map again to move ground zero to a different spot, or choose Pick another city to return to the globe.

What do the red and amber buildings mean?

For smaller yields the map shows 3D buildings. Buildings inside the 5 psi ring turn red, where most houses would collapse or be badly damaged. Buildings between the 5 psi and 1 psi rings turn amber, where windows would break and damage would be lighter. Buildings outside the 1 psi ring stay dark.

Why do the buildings disappear for large yields?

For large yields the damage rings stretch across a whole region, and individual buildings are far too small to see at that distance. In that case the map shows the effect rings only, and the camera pulls back to fit them.

Can I search for my own town?

The search box covers a built-in list of large cities, so smaller towns may not appear. You can still pick any location by clicking the globe near your town and then clicking the exact spot on the map.

What is in a share link?

A share link contains four values: the latitude and longitude of ground zero, the yield in kilotons, and the burst type. Nothing else is included. If you would rather not reveal a place that matters to you, pick a different point before sharing.

Where does the map data come from?

Map tiles and building footprints come from OpenFreeMap, which is built on OpenStreetMap data. The city list comes from GeoNames. Building coverage and heights vary from place to place, so some areas show fewer buildings than exist.

Does the map show how many people would be affected?

No. The current version shows distances only. It does not estimate casualties, and any population figures added in future will only describe how many people live inside a zone.