Why Do Whales Explode? Usually Because Someone Helped

Florence, Oregon, Thursday 12 November 1970. A state highway crew has spent the day stacking twenty cases of dynamite against something 45 feet long that washed up on the beach three days earlier and has been rotting there since. The charge goes off. Spectators run for the parking lot while lumps of blubber come down around them, one slab flattening a parked car.

That sperm whale is the reason the question exists at all. Almost everyone who has seen the footage files it under decomposition, and it belongs under demolition.

Why do whales explode?

Dead whales bloat because gut bacteria keep digesting after the animal dies, filling a body sealed by thick blubber and tough skin with carbon dioxide, methane, hydrogen sulfide and ammonia. Pressure rises until something gives. Recorded bursts are rare, though, and most of them were set off by people cutting into, lifting or dynamiting the carcass.

The bacteria are already inside

A whale does not need to catch anything to start rotting. Its gut is already full of microbes, and once circulation stops they keep working and start travelling. The StatPearls reference chapter on postmortem changes, hosted by the US National Library of Medicine, names Clostridium perfringens as the principal agent, describes normal gut flora migrating out of the gastrointestinal tract into the blood vessels, and lists what the process gives off: hydrogen sulfide, ammonia, carbon dioxide and methane.

Two things make a whale a better container for that than a horse or a herring. Skin and blubber wrap the abdomen in a tough, closed layer, so the gas has nowhere convenient to go. The same fat layer is insulation, and it holds in the heat that decay itself produces, which matters because the same chapter records that chemical activity roughly doubles for every 10 degrees Celsius of extra temperature, and that a high body fat content speeds putrefaction on its own. A large, well-wrapped, self-warming animal works through itself faster than a small cold one.

The gas is mostly carbon dioxide

Popular accounts reach for methane, because methane is the gas people associate with rot. When Yara Bernaldo de Quiros and colleagues sampled the bubbles inside stranded marine mammals for Frontiers in Physiology in 2012, the well-decomposed animals gave up something else. Their bubbles were high in carbon dioxide with hydrogen alongside it, nitrogen usually under 40 percent, and some samples came back at 100 percent carbon dioxide. Hydrogen was the reliable marker of putrefaction, appearing in the more decayed carcasses.

Oregon’s whale was blown up on purpose

The version that circulates, in which the 1970 Florence whale burst on its own, is folklore assembled backwards from the video. The Eugene Register-Guard reported on 11 November that the animal had come ashore the previous Monday, 45 feet long and eight tons. Oregon beaches were then the responsibility of the state Highway Division, which had consulted the US Navy and settled on explosives, on the theory that the pieces would be small enough for scavengers to clear.

Assistant district engineer George Thornton ran the job with twenty fifty-pound cases, half a ton in all. The blast threw up a hundred-foot column of sand and whale and dropped a chunk on a late-model Oldsmobile a quarter of a mile away, in a beachside parking lot, belonging to a Springfield businessman named Walter Umenhofer. His claim against the state was later settled for an undisclosed sum, and his own summary was “They’re just lucky they didn’t kill somebody.” Thornton’s was “It went just exactly right. Except the blast funneled a hole in the sand under the whale.”

The film everyone has seen is not a whale exploding. It is a whale being exploded, by a state highway department, with half a ton of dynamite and a television crew standing in the dunes.

Questions pick up their answers long after the fact, the way a riddle about a raven and a writing desk did, and this piece of film has been answering the wrong one for fifty-five years.

Three famous bursts, three different causes

Case	What the carcass did	What set it off
Florence, Oregon, 12 Nov 1970	45-foot sperm whale broken apart on the sand	Half a ton of dynamite
Tainan, Taiwan, 26 Jan 2004	17-metre sperm whale burst in a city street	Being craned onto a truck and driven
Faroe Islands, 26 Nov 2013	Sperm whale carcass burst at a disused whaling station	A flensing knife

All three were sperm whales, the species that in life rests hanging upright 10 to 20 metres below the surface. The Taiwanese whale stranded on 17 January 2004. National Cheng Kung University would not host the necropsy on campus, so the carcass was bound for a nature reserve instead, and loading it took 50 workers, three cranes and 13 hours. It let go nine days after beaching, in traffic, coating shop fronts, parked cars, the road and the people on it. That case is the closest of the three to a whale doing it unaided, and it still took a crane crew and a flatbed to bring the moment on.

The Faroese carcass, on 26 November 2013, was opened deliberately. A dead sperm whale had been towed to a disused whaling station so its bones could be harvested for a museum display, and Bjarni Mikkelsen, a marine biologist at the National Museum of the Faroe Islands, was cutting it open when the body blew out and tore the two-handed flensing knife from his hands.

Marine biology is full of events nobody has managed to watch on purpose, including the entire sex life of the eel. Whale bursts tend to be well recorded, because a camera is usually present wherever a crew is already working on a carcass.

The modern options do not include explosives

NOAA Fisheries publishes what actually happens to a dead whale now. The carcass can be left to decompose where it lies, moved somewhere remote, buried above the high tide line, towed offshore to float or sink, or taken away for incineration, composting, rendering or a landfill. Towing is a ship job, and ships bring their own vocabulary with them, including a deck whose name has nothing to do with the obvious. The agency’s instruction to everyone else is one line: “Do not attempt to touch, handle, remove parts, or return the carcass to the water.” Stranded animals carry infectious diseases that pass to people and pets, and responders work in protective clothing, gloves, masks and eye protection.

The archive at theexplodingwhale.com catalogues twelve such events between 2001 and 2013, in Australia, South Africa, Taiwan, California and the Faroes. Its own taxonomy sorts them into carcass removal, euthanasia and putrefaction, and only that last heading describes a whale acting alone. Two burst carcasses sit under it, Tainan and a California whale in August 2005, alongside an Alaskan humpback filed there for the opposite reason: gut inflated, skin intact, nothing detonated.

The normal outcome is undramatic. NOAA’s description of a carcass left where it lies is that it will “slowly break down over many months or years, returning nutrients to the environment.”

A dead whale on a beach is a sealed bag of warm fat with its own bacteria working through it, and left to itself it is mostly a smell and an instruction not to touch anything. What turns one into footage is nearly always a person arriving with a knife, a crane or twenty cases of dynamite. Strictly FYI.