Krakatoa's 1883 eruption collapsed roughly two-thirds of the original island below sea level. Toggle the sea-level plane to see how much of the caldera is now underwater, and the 1883 outline to see how much bigger the island used to be.
Published figures: three surviving island remnants ring the caldera, the tallest (Rakata) rising roughly 700-800 m; Anak Krakatau has been rebuilding near the middle of the flooded basin since 1927, most recently after a large December 2018 flank collapse.
Drag to orbit and scroll or pinch to zoom. Everything renders on your device with WebGL.
Krakatoa 3D Explorer
This browser explorer shows Krakatoa as a collapsed island caldera in the Sunda Strait: three surviving fragments of the original island ringing a submerged basin, and Anak Krakatau - the young volcano growing back from the sea near the middle of that basin.
The 1883 eruption destroyed roughly two-thirds of the original island of Krakatoa, collapsing most of it below sea level in one of the most violent eruptions in recorded history. The blast is commonly cited as one of the loudest sounds ever recorded, reportedly heard about 4,800 km away, and the tsunamis it triggered killed on the order of 36,000 people around the Sunda Strait. What remained above water split into three fragments: Rakata, the largest, with a dramatic sheer cliff rising roughly 700-800 m; and the smaller Sertung and Panjang. Since 1927, a new volcano - Anak Krakatau, "Child of Krakatoa" - has been rebuilding near the middle of the flooded caldera, with most of its bulk still hidden below the waterline. A large flank collapse in December 2018 stripped away much of the young cone and triggered another deadly tsunami; the volcano has kept rebuilding since.
- Toggle the sea-level plane to see how much of the caldera lies underwater
- Toggle the 1883 outline to compare today's remnants with the island's former size
- Read location, eruption, and remnant-island figures in the panel
- Drag to orbit, scroll or pinch to zoom
- Runs fully in the browser with the vendored three.js engine - no account, no upload
| Figure | Published value |
|---|---|
| Location | Sunda Strait, Indonesia - between Java and Sumatra |
| 1883 eruption | destroyed roughly two-thirds of the original island; tsunamis killed on the order of 36,000 people |
| Blast noise | commonly cited as one of the loudest sounds ever recorded, reportedly heard about 4,800 km away |
| Surviving remnants | Rakata (tallest, about 700-800 m), Sertung, and Panjang |
| Anak Krakatau | emerged from the sea in 1927; grows through repeated small eruptions |
| December 2018 | a flank collapse triggered a deadly tsunami and removed much of the cone's height; rebuilding has continued since |
For other active volcanoes on this site, open the Kilauea 3D Explorer or the Mount Vesuvius 3D Explorer.
The whole Krakatoa scene - the submerged caldera floor, the three remnant islands, the regrowing Anak Krakatau cone, and the sea-level and 1883-outline toggles - is built and drawn on your own device with WebGL through the site-vendored three.js engine. Orbit the scene to swing around the caldera, and zoom in to compare the surviving islands against the translucent outline of the much larger island that stood there before 1883. Nothing about your visit is uploaded to a server, and the engine loads once (about 0.7 MB) and is then cached.
This is an educational approximation - the caldera shape, remnant islands, cone, and 1883 outline are schematic teaching cues, not survey terrain.
Frequently Asked Questions
Why did Krakatoa collapse in 1883?
The 1883 eruption was one of the most violent in recorded history. It destroyed roughly two-thirds of the original island, collapsing most of it below sea level and leaving a submerged caldera behind.
Where is the new volcano growing from?
Anak Krakatau ("Child of Krakatoa") emerged from the sea near the middle of the flooded caldera in 1927 and has been growing intermittently since, through repeated small eruptions. Most of its bulk is still hidden below the waterline.
How loud was the 1883 eruption really?
It is commonly cited as one of the loudest sounds ever recorded, reportedly heard about 4,800 km away. The resulting tsunamis killed on the order of 36,000 people around the Sunda Strait.
What happened to Anak Krakatau in 2018?
In December 2018 a large flank collapse removed much of the young cone's height and volume and triggered another deadly tsunami. The volcano has continued rebuilding since.
Where is Krakatoa located?
In the Sunda Strait, Indonesia, between the islands of Java and Sumatra.
Is this a scientific terrain model?
No. It is an educational explorer using published figures - the caldera shape, remnant islands, cone, and 1883 outline are schematic teaching cues, not survey terrain.