Krakatoa 1883: The Loudest Sound in Recorded History
On August 27, 1883, the volcanic island of Krakatau in Indonesia's Sunda Strait exploded with a force equivalent to 200 megatons of TNT — four times the largest nuclear weapon ever detonated. The sound traveled 4,800 km. The tsunamis reached 41 meters. At least 36,417 people died. And then, from the caldera, a new island grew.
By VolcanoDB Research Team. Data: Smithsonian GVP, NCEI/NOAA, PVMBG Indonesia.
What Happened at Krakatoa in 1883?
The 1883 eruption of Krakatau (often anglicized as "Krakatoa") wasn't just a volcanic disaster — it was the first global catastrophe of the modern media age. Telegraph cables carried the news worldwide within hours. The atmospheric shockwave was measured on barometers in London, Washington, and Tokyo. For the first time, the whole world experienced a volcanic eruption together.
The eruption had been building since May 1883, with steam venting and ash columns rising from Perboewatan crater. Ship captains reported pumice clogging the Sunda Strait. But nothing prepared anyone for August 27.
Between 5:30 AM and 10:02 AM, four colossal explosions tore the island apart. The final blast — at 10:02 AM local time — was the single most violent volcanic event in modern history. The explosion collapsed two-thirds of the island into the sea, creating a caldera 6 km wide. The resulting tsunamis swept through the Sunda Strait at terrifying speed, obliterating 295 coastal towns and killing at least 36,417 people. Over 34,000 of those deaths came from the tsunamis, not the eruption itself.
For context, this was the same Indonesian volcanic arc that produced the 1815 Tambora eruption (VEI 7, 71,000+ killed) just 68 years earlier. The Sunda Arc sits where the Indo-Australian Plate subducts beneath the Eurasian Plate — one of the most volcanically active zones on the planet.
The 1883 Eruption by the Numbers
I've cross-referenced data from NCEI/NOAA, the Smithsonian GVP, and primary historical sources to build what I think is the most complete impact summary available. Every number here is sourced.
Metric
Value
In Context
Energy released
200 megatons TNT
4× the Tsar Bomba (largest nuclear weapon ever detonated)
Sound level
310 decibels
Heard 4,800 km away — the distance from London to Khartoum
Ash column height
80 km
Into the mesosphere — 9× higher than commercial aircraft
Tsunami height
Up to 41 m
Taller than a 12-story building. Destroyed 295 towns
Temperature drop
0.5°C globally
Temperatures didn't return to normal until 1888 — 5 years later
Pressure wave
3.5 circumnavigations
Barometers worldwide recorded the shockwave for 5 days
Material ejected
25 km³
Enough to bury Manhattan under 400 meters of ash
Death toll
36,417+
Over 34,000 from tsunamis, not the eruption itself
The Loudest Sound in Recorded History
This is the fact that stops people mid-sentence: the 10:02 AM explosion on August 27 measured approximately 310 decibels at the source. That number is almost incomprehensible. A jet engine at close range is 150 dB. The pain threshold is 120 dB. At 310 dB, you're not hearing a sound — you're being hit by a wall of compressed air.
The sound was distinctly heard 4,800 km away on Rodrigues Island near Mauritius, where it reportedly sounded like distant cannon fire. People in Perth, Australia — 3,100 km away — heard it too. The pressure wave was detected on barometers worldwide for five straight days as it bounced back and forth across the planet 3.5 times. Nothing before or since has come close.
Sailors on the British ship Norham Castle, 64 km from Krakatau, reported that the blast ruptured eardrums of crew members. The captain wrote: "So violent are the explosions that the ear-drums of over half my crew have been shattered."
Tsunamis: 41-Meter Waves That Killed 34,000
The collapse of two-thirds of Krakatau island into the caldera displaced a staggering volume of seawater. The largest wave recorded in Banten province measured approximately 41 meters (135 feet) — taller than a 12-story building. Smaller but still devastating waves of 15–30 meters struck both sides of the Sunda Strait.
The town of Merak was completely erased. Anjer was wiped from the map. In total, 295 towns were destroyed. A gunboat, the Berouw, was carried 2.5 km inland and deposited 9 meters above sea level. Over 34,000 of the 36,417 confirmed deaths were caused by the tsunamis, not by the eruption directly.
Tide gauges detected the waves as far away as the English Channel — over 17,000 km from the eruption. The tsunamis are one reason Krakatoa's destructiveness is often compared to the 2004 Indian Ocean tsunami, which also devastated Indonesian coastlines. For more on the types of volcanic hazards that can generate tsunamis, see our guide to pyroclastic flows.
Global Climate and Cultural Impact
Krakatoa injected massive quantities of sulfur dioxide into the stratosphere, creating a veil of sulfuric acid aerosols that reflected sunlight for years. Global temperatures dropped by about 0.5°C and didn't fully recover until 1888 — five years after the eruption.
The atmospheric effects produced some of the most spectacular sunsets in recorded history. For months after the eruption, skies around the world glowed vivid red and orange at dusk. Fire departments in New York and Connecticut reportedly responded to false alarms from residents who thought the sky was on fire.
Art historians have long debated whether these apocalyptic sunsets inspired Edvard Munch's 1893 painting The Scream. Munch lived in Oslo, and his diary describes a walk where "the sky turned blood red." The timing and geography are consistent with Krakatoa's stratospheric aerosols reaching Scandinavia in late 1883. It's circumstantial, but compelling.
The eruption also launched the field of modern climate science. It was the first time scientists systematically studied how a volcanic eruption could alter global weather patterns. The Royal Society of London published a 494-page report in 1888 analyzing the atmospheric, oceanic, and climatic effects — a document that remains foundational in volcanology.
Complete Eruption Timeline: From Ancient Caldera to Anak Krakatau
Our database records 20 eruptions for Krakatau. Here are the most significant events, combining Smithsonian GVP data with historical records.
1
~416 AD
VEI 6?
Catastrophic caldera-forming eruption destroyed most of the original Krakatau island. Some researchers link this to the 'Javanese Book of Kings' account of a massive explosion that separated Java and Sumatra. The island was uninhabited for centuries afterward.
2
1680
VEI 2
First historically documented eruption. Dutch merchant Johann Wilhelm Vogel observed the activity and described the island as 'high and pointed, covered with trees, whose trees and foliage were half burned.' Mild eruption after at least 200 years of dormancy.
3
May 1883
Precursory eruptions begin. On May 20, steam venting from Perboewatan crater sends ash columns 6 km high. Explosions heard 160 km away in Batavia (Jakarta). Activity continues sporadically through June and July. Ship captains report pumice floating in the Sunda Strait.
4
Aug 26, 1883
Eruption intensifies dramatically. By 1:00 PM, the climactic phase begins. A black ash column reaches 27 km. Explosions every 10 minutes. By 5:00 PM, audible across all of Java. Small tsunamis begin hitting the Sunda Strait coastline. The town of Anjer is partially damaged.
5
Aug 27, 1883
VEI 6
Four cataclysmic explosions between 5:30 and 10:02 AM. The third, at 10:02 AM, is the loudest sound in recorded history — 310 dB, heard 4,800 km away in Rodrigues Island near Mauritius. The pressure wave circled the globe 3.5 times. Two-thirds of the island collapsed into the sea. Tsunamis up to 41 meters obliterated 295 coastal towns. At least 36,417 killed.
6
1884–1927
The caldera fills with seawater. Submarine eruptions reported periodically. On December 29, 1927, fishermen spot steam and debris rising from the water — Anak Krakatau ('Child of Krakatau') is born. The island repeatedly emerges and is washed away before permanently establishing itself in 1930.
7
1960–2018
VEI 1–2
Anak Krakatau grows steadily at 7–9 meters per year. Frequent Strombolian eruptions build a cone reaching 338 meters by late 2018. Regular volcanic tourism develops — boat tours from Anyer and Carita on Java's west coast become popular.
8
Dec 2018
VEI 3
DISASTER. On December 22, the southwestern flank of Anak Krakatau collapses during eruption, sending roughly 0.2 km³ of rock into the sea. A tsunami strikes without warning — no earthquake precursor to trigger alerts. Waves up to 5 meters hit the Sunda Strait coast. 437 killed, 14,059 injured, 33,000 displaced. The island loses two-thirds of its volume, shrinking from 338 m to just 110 m elevation.
9
2020–2026
VEI 1–2
Anak Krakatau rebuilds. Strombolian eruptions and ash plumes continue intermittently. As of early 2026, the island shows ongoing low-level activity with ash plumes reaching 2–3 km. Alert Level 3 (of 4). A 2–5 km maritime exclusion zone remains in effect. The volcano is monitored intensively by PVMBG due to collapse risk.
Anak Krakatau: The Child That Won't Stop Growing
Anak Krakatau first broke the ocean surface on December 29, 1927 — 44 years after its parent island destroyed itself. The young stratovolcano grew relentlessly, adding 7–9 meters of height annually through frequent Strombolian eruptions. By late 2018, it stood 338 meters tall — a popular destination for adventurous boat tourists.
Then, on December 22, 2018, the southwest flank collapsed without warning. No earthquake preceded the collapse — the standard tsunami warning system was useless. Roughly 0.2 km³ of volcanic material slid into the Sunda Strait, generating waves up to 5 meters that struck the coasts of Java and Sumatra. The death toll: 437 killed, 14,059 injured, 33,000 displaced.
Post-collapse surveys revealed that Anak Krakatau lost two-thirds of its volume overnight, shrinking from 338 m to just 110 m above sea level. But volcanism doesn't stop. The island is rebuilding. Intermittent eruptions continue. And volcanologists are watching closely — because flank collapses are among the hardest volcanic hazards to predict.
Anak Krakatau 2026: Current Status
Alert Level 3 (of 4) — May 2026
Anak Krakatau shows ongoing low-level Strombolian eruptions with ash plumes reaching 2–3 km altitude. Gas and steam emissions continue from the summit crater. A 2–5 km maritime exclusion zone is enforced. Maritime and aviation alerts are active. No landing permitted.
PVMBG monitors the island intensively using seismometers, tiltmeters, and satellite thermal imaging. The primary concern isn't an 1883-scale eruption (extremely unlikely) but another flank collapse generating a tsunami — as happened in 2018.
The current activity at Anak Krakatau is typical for a young, actively growing post-caldera volcano. What makes it dangerous isn't the eruption style — it's the geography. The Sunda Strait is one of Indonesia's busiest shipping lanes, and millions of people live on the coastlines within tsunami reach.
Krakatoa vs. Other Famous Eruptions
Where does Krakatoa rank? Here's how the 1883 eruption compares with other volcanic disasters from our database:
What makes Krakatoa unique isn't sheer power — Tambora was 10 times larger. It's the combination of scale, timing, and global impact. In 1883, the telegraph connected the world for the first time, and Krakatoa was the first disaster broadcast globally in near-real-time. The atmospheric and oceanic effects were measured with precision instruments. And the aftermath — Anak Krakatau's birth, growth, collapse, and rebuilding — continues the story into the present day.
Visiting Krakatau: What to Expect
Boat tours to the Krakatau caldera depart from Anyer or Carita on Java's west coast — about 3 hours by car from Jakarta. The boat trip takes 2–3 hours each way depending on sea conditions. You won't land on Anak Krakatau during elevated activity (currently Alert Level 3), but the approach offers dramatic views of the smoking island against the open sea.
Most tour operators charge $100–200 per person for a full-day trip including snorkeling around the caldera rim. May through September is the best window — the Java Sea is calmer and visibility is higher. Several operators also offer camping trips to nearby Rakata island (the surviving remnant of the 1883 island) when conditions allow.
For a broader Indonesia volcano itinerary, see our guide to volcanoes in Indonesia covering Bromo, Ijen, Rinjani, and more. You can also explore the individual Krakatau database page for full eruption data.
Explore Krakatau in Our Database
Full eruption history, coordinates, VEI data, and geological classification for Krakatau
No, but it's the most famous. The 1883 eruption was VEI 6 — extremely powerful, but not the largest. The 1815 Tambora eruption (also in Indonesia, just 68 years earlier) was VEI 7 — roughly 10 times more powerful and killed 71,000–92,000 people. The largest known eruption, Toba around 74,000 years ago, was VEI 8. Krakatoa's fame comes from its timing — it happened during the age of telegraph, so it was the first global volcanic disaster reported in real time worldwide.
Is Anak Krakatau dangerous right now?
Yes. Anak Krakatau remains at Alert Level 3 (of 4) as of 2026, with a 2–5 km maritime exclusion zone. The volcano shows ongoing Strombolian activity with intermittent ash plumes reaching 2–3 km altitude. The 2018 flank collapse proved that Anak Krakatau can generate tsunamis without warning — the landslide that killed 437 people wasn't preceded by an earthquake. PVMBG monitors the volcano intensively, but flank collapses are inherently difficult to predict.
Why was the Krakatoa sound heard so far away?
The 10:02 AM explosion on August 27, 1883 reached approximately 310 decibels at the source — far beyond the threshold of pain (120 dB) or instant hearing damage (150 dB). The energy was so enormous that the acoustic pressure wave traveled through the atmosphere at the speed of sound, circling the Earth 3.5 times over 5 days. Barometers as far away as England detected the pressure fluctuation. The sound was clearly audible 4,800 km away on Rodrigues Island near Mauritius. At that distance, it reportedly sounded like distant cannon fire.
Can you visit Krakatoa / Anak Krakatau?
When conditions allow, yes — boat tours from Anyer or Carita on Java's west coast take visitors to the Krakatau caldera. The trip takes 2–3 hours by speedboat. You can't land on Anak Krakatau during elevated activity (currently Alert Level 3), but the boat approach offers dramatic views of the smoking island. Tour prices typically range $100–200 per person for a full-day trip. May–September offers the calmest seas. Always check PVMBG alert levels before booking.
Did Krakatoa cause the year without a summer?
No — that's a common mix-up. The 'Year Without a Summer' (1816) was caused by the eruption of Mount Tambora in 1815, not Krakatoa. However, Krakatoa did cool the planet. Sulfur dioxide injected into the stratosphere reflected sunlight, dropping global temperatures by about 0.5°C for several years. The volcanic aerosols created vivid red and orange sunsets worldwide — which may have inspired the fiery sky in Edvard Munch's painting 'The Scream' (1893).