TheStrangeFile

SF-0039Nature Is Terrifying

Case Reopened: we quoted a USGS article word for word and still dropped its condition

For seven weeks our Pele's hair file pinned a water-tank instruction on a January 2025 USGS article. The article's sentence was quoted exactly. The words before it, "if you are concerned", were missing.

Published
Sources
8 primary / authoritative
A close-up photograph of a dense tangle of extremely fine, pale golden-brown fibres lying on a rough, speckled grey surface, matted together like a hank of hair. A bright magenta highlighter cap, with its clip, lies diagonally across the tangle for scale, with individual strands draped over it. Dark flecks of grit are scattered across the surface.

The same photograph as SF-0026: Pele's hair that fell at the USGS Hawaiian Volcano Observatory field station during Kīlauea's episode 46, in May 2026 — more than a year after the January 2025 fall the downpipe advice was written about. The highlighter cap is the scale.

Original captionThis macro photograph shows Pele's hair, strands of volcanic glass, that had accumulated into a tumble-weed-like structure where it fell at the USGS Hawaiian Volcano Observatory field station near Kilauea Military Camp in Hawaiʻi Volcanoes National Park. A highlighter cap provides a scale.

Image
K. Mulliken
Taken
2026-05-05
Location
USGS Hawaiian Volcano Observatory field station near Kīlauea Military Camp, Hawaiʻi Volcanoes National Park, Hawaii
Archive ref.
USGS media library — IMG_3571
The image itself
Authentic, unaltered

Pele's hair, Kīlauea episode 46, 5 May 2026. K. Mulliken, US Geological Survey Hawaiian Volcano Observatory. Public domain. Cropped.

The claim, as it circulates

"The USGS asks residents to disconnect the downpipes feeding their water tanks while it is falling." — The Strange File, SF-0026, as published from 2026-08-07 until the correction of 2026-09-25.
Mostly True

The core of the claim holds up, but a specific detail as it circulates is wrong or overstated.

The advice is real; the attribution drifted. USGS guidance tells households on roof-catchment tanks to disconnect the downpipe when ash is forecast or before it falls, and the tephra guidance HVO now points readers to gives the same step to everyone "If tephra fall is possible", Pele's hair included. What SF-0026 got wrong was the source it hung the step on. It attributed an unconditional instruction to one HVO article, from January 2025, which offered the step only to the concerned and said the fall it described usually needed no action. That is a true story whose attribution drifted, and the drift is identified and sourced here. Mostly True.

ESTABLISHED — THE WORDS ARE HVO'S, AND ONE CONDITION SURVIVED. The article contains the sentence "Disconnect the downpipe that connects your gutter system to your tank when Pele's Hair is falling." SF-0026 kept "while it is falling". The body quoted HVO's sentence exactly.

ESTABLISHED — THE ARTICLE'S CONDITION WAS DROPPED. HVO's sentence is the answer to one that comes before it: "However, if you are concerned about Pele's Hair getting in your water catchment system during future lava fountain episodes, there are steps you can take to prevent that from happening." In that article the step is offered to people who are worried. It is not asked there of everyone.

ESTABLISHED — THE ARTICLE SAYS THE FALL IT DESCRIBES USUALLY NEEDED NO ACTION. "The recent eruption episode deposited less than 1 millimeter (a fraction of an inch) of Pele's Hair in communities near Kīlauea's summit. This amount usually does not require any action but it's good to be aware and prepared in case more Pele's Hair falls in the future or accumulates over time." And on water in particular: "The amount of Pele's Hair that fell recently was small enough to be handled by most general filtration systems." SF-0026 never carried the filtration sentence.

ESTABLISHED — USGS GUIDANCE GIVES THE STEP WITHOUT THE ARTICLE'S CONDITION. The USGS volcanic ash impacts website, under "Key Actions for Everyone in an Ashfall" and "If ashfall is forecast:", says: "Disconnect downpipes from roof catchment rainwater tanks to keep ash out." Its water-supply page says: "For roof catchment rainwater systems, we advise disconnecting the downpipe from the roof to the tank prior to the ashfall." Its roof-catchment page, which the article links at "water catchment system", says to "disconnect the downpipe now" if ash is already on the roof. All three are about ash. The article says "Much of the general guidance about volcanic ash exposure and cleanup can be applied to Pele's Hair, though the two are not exactly the same."

ESTABLISHED — THE GUIDANCE HVO POINTS TO NOW NAMES PELE'S HAIR. HVO's daily update of 25 September 2026 ends its tephra advice with: "More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/". That guidance counts Pele's hair as tephra, and under "GENERAL ADVICE FOR EVERYONE DURING TEPHRA FALL" and "If tephra fall is possible:" it says: "Disconnect downpipes from roof catchment tanks to keep tephra out." It is published by the University of Hawaiʻi Sea Grant College Program, with the Hawaiʻi County Civil Defense Agency and USGS logos on its cover. This file does not attribute its words to the USGS.

THE REMAINDER. True: USGS guidance advises households on catchment tanks to disconnect the downpipe before and during ashfall; the article applies much of the ash guidance to Pele's hair; and the current guidance HVO directs readers to says to disconnect whenever tephra fall is possible. Not true: that the January 2025 article SF-0026 cited asked residents to do so. It offered the step to the concerned, "during future lava fountain episodes", and said the fall it described "usually does not require any action" and was small enough for most filters. SF-0026 put an unconditional instruction in that article's mouth and left out its reassurance.

Mostly True rather than Misleading, because Misleading needs a false conclusion, and the conclusion a reader of SF-0026's summary would draw, that USGS guidance tells households on catchment water to disconnect the downpipe while material is falling, is one that USGS ash guidance and the HVO-linked tephra guidance support. The error is in which document said it and on what terms, which the verdict standard names as the Mostly True case: "a true story where a number, date, or attribution drifted". This file's first draft rated the sentence Misleading, on the view that the dropped condition was the claim. That view depended on the article being the only relevant guidance, and it is not. Not Verified, because the attribution SF-0026 printed, and its silence on the article's reassurance about January 2025, are real errors about what a cited source said. SF-0018 is rated Mostly True for a dropped USGS qualifier, and this verdict is consistent with it.

Confidence is moderate. The step from ash guidance to Pele's hair rests on the article's "Much of the general guidance" and on the HVO-linked tephra guidance, which is not a USGS publication; no USGS page read for this file names Pele's hair in its downpipe advice. An editor who holds that the test is only what the cited article said could still argue Misleading. That case is set out in the contradicting evidence.

The photograph, as on SF-0026, is authentic and is K. Mulliken's, for the USGS. It was never the thing at fault.

Mostly True requires 1 primary or authoritative source. This file cites 8.

Every verdict, and what each one has to clear

From 7 August to 25 September 2026, SF-0026 said: "The USGS asks residents to disconnect the downpipes feeding their water tanks while it is falling." USGS ash guidance does advise that, and the tephra guidance HVO now points to gives the step to everyone when a fall is possible. But the January 2025 article SF-0026 cited offered it only to the concerned, and said that fall "usually does not require any action". The page also misnumbered the episode and dropped three hedges. SF-0026 stays Verified. That sentence was Mostly True.

What the page said

SF-0026 is about Pele’s hair: strands of volcanic glass that Kīlauea’s lava fountains pull out of molten rock, fine enough to drift on the wind into the towns near the summit. Its verdict is Verified, and it still is.

For seven weeks, from 7 August to 25 September 2026, its summary also said this:

The USGS asks residents to disconnect the downpipes feeding their water tanks while it is falling.

The same idea ran through the page. The line meant to be retold said the USGS “tells them to disconnect the downpipe to their water tank”. An evidence finding said residents “are told to” disconnect it, “because it can contaminate catchment water”. The body introduced the advice with “Residents on catchment water are told:”.

What the USGS article says

The source is a Volcano Watch article from the USGS Hawaiian Volcano Observatory, published on 23 January 2025, after the fall on Volcano Village and its neighbours. It is written as answers to the questions residents were asking:

You may be wondering if there are steps you need to take regarding vehicles, pets and children being outside, grazing livestock, or water catchment systems if you live in an area that has been affected by Pele’s Hair.

Its first answer is about quantity. The fall left “less than 1 millimeter (a fraction of an inch) of Pele’s Hair in communities near Kīlauea’s summit”, and:

This amount usually does not require any action but it’s good to be aware and prepared in case more Pele’s Hair falls in the future or accumulates over time.

It also gives advice on exposure:

Both Pele’s Hair and volcanic ash are abrasive and can irritate eyes, skin, and respiratory systems. Limiting exposure is the best way to avoid being impacted; consider wearing protective clothing or equipment (gloves, eye protection, facemask) if you cannot limit your exposure.

Then, on water:

The amount of Pele’s Hair that fell recently was small enough to be handled by most general filtration systems. However, if you are concerned about Pele’s Hair getting in your water catchment system during future lava fountain episodes, there are steps you can take to prevent that from happening. Disconnect the downpipe that connects your gutter system to your tank when Pele’s Hair is falling.

In this article the step is HVO’s, and it is addressed to residents who are worried about future episodes. On water, the article’s answer about the January 2025 fall was that most filters could cope.

What the USGS’s wider guidance says

The article is not the USGS’s only word on catchment tanks, though it was the only one SF-0026 cited. The article links its words “water catchment system” to a separate USGS page on roof catchment tanks, written for volcanic ash. That page calls these systems “very vulnerable to contamination by volcanic ashfall”, and its next sentence says: “Tank water contaminated by ash is unlikely to be a health hazard as elements released from the ash (particularly iron, manganese and aluminium) can impart an unpleasant metallic taste to the water making it unpalatable to drink, with this effect outweighing the release of any toxic elements such as fluorine from the ash.” Its advice to households on tank water includes:

If you have ash on your roof and you did not disconnect your downpipe from your rainwater tank, disconnect the downpipe now to protect your tank water.

Two more pages on the same USGS site put it before the fall, not after. Under “Key Actions for Everyone in an Ashfall”, and “If ashfall is forecast:”, one says: “Disconnect downpipes from roof catchment rainwater tanks to keep ash out.” The other: “For roof catchment rainwater systems, we advise disconnecting the downpipe from the roof to the tank prior to the ashfall.” These pages are about ash. The article says “Much of the general guidance about volcanic ash exposure and cleanup can be applied to Pele’s Hair, though the two are not exactly the same”, and does not say which parts.

The guidance HVO sends readers to now is plainer still. HVO’s daily update of 25 September 2026 ends its advice on tephra, which it says includes Pele’s hair, with: “More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/”. That guidance is published by the University of Hawaiʻi Sea Grant College Program, with the logos of the Hawaiʻi County Civil Defense Agency and the USGS on its cover. It counts Pele’s hair as tephra, and in its general advice for everyone during tephra fall it says:

If tephra fall is possible:

Disconnect downpipes from roof catchment tanks to keep tephra out. Cover the tanks (see Specific Guidance for Water Catchment Systems below).

Its section for catchment households adds: “To prevent contamination of your tank water, cover the water tank with a tarp and disconnect the downpipe.”

SF-0026 cited none of these pages. This file’s first draft read none of them, and its second read only the roof-catchment page; reviewers found the rest. Together they settle what SF-0026 got right and what it got wrong. The advice it gave is real, current advice. What it got wrong was where it said the advice came from, and what that source said about the fall it described.

The quotation was exact. The error was the sentence before it.

This is the part worth stopping on. SF-0026’s body quoted HVO’s instruction word for word, in a block quote, with “when Pele’s Hair is falling” intact. Nothing inside those quotation marks was wrong.

What went missing was HVO’s own set-up: the sentence that says most filters could cope, and the clause that makes the step conditional on concern. Take those away and the quotation changes meaning. In the article, it was a step offered to the worried, after a fall the article said usually needed no action. On our page, it became that article’s instruction to everyone.

This publication has a collection called The Qualifier Is The Story. It is built on one habit: reading the sentence the famous line came from, because the popular version is usually that line with a hedge deleted. Here the hedge was deleted by this publication, from an agency’s safety advice, in a file that sits in that collection. The mechanism is the same one we look for in other people’s claims. We didn’t catch it in our own.

It is also an easy error to excuse, and part of the excuse holds. Stated as an instruction, the advice sounds more careful, and the USGS’s wider guidance does state it that way. That may be why it got past both the writing and a cooling-off review. But SF-0026 did not cite the wider guidance. It cited an article whose message about the January 2025 fall was that most filters could cope and that the step was there for the worried, and it put an instruction in that article’s mouth.

Two smaller things, of the same kind

The episode. SF-0026 said HVO gives the January dates as “the fifth of five fountaining episodes”. HVO says the fall came “during episode 4, from January 15–18”, when there were no tradewinds. The fifth episode is the one the article says ended at 4:30 a.m. on 23 January, the day it was published.

Three hedges. HVO says the strands “can be more than a meter (3 feet) long”, and the observatory’s 2023 article says they “are often less than 1 millimeter (0.04 inches) thick”. The tangles formed “In some areas”. SF-0026’s hook dropped “can be”, its body dropped “often”, and its summary dropped “in some areas”. Each of these turned what is possible into what always happens.

All of it is corrected on SF-0026, with a dated entry in its Corrections section and on the corrections ledger.

Why SF-0026 is still Verified

SF-0026 tested a claim about the material, not about the advice. Its claim statement is that Kīlauea produces strands of volcanic glass “which are over a metre long, thinner than a millimetre, blow across inhabited areas on the wind, and collect into tumbleweed-like masses.” HVO says, of Kīlauea’s own fountaining and in the same article, that the strands “can be more than a meter (3 feet) long and less than 1 millimeter (0.04 inches) thick”, that they fell on named communities, and that in some areas they tangled into structures up to 60 cm long. The claim statement does not carry HVO’s “can be”. This file reads it as a claim that such strands exist, which HVO supports, and this file’s uncertainties say so. The downpipe line was context in that file. It was recorded as context, and the verdict did not rest on it.

That is why this is a separate file with its own verdict. Under the corrections policy, verdicts change only on new evidence, and no evidence about the claim SF-0026 tested has changed. What changed is that one of its sentences has now been tested as a claim in its own right. On those terms it is Mostly True: the advice is real USGS advice, and the article it was pinned to did not give it that way.

SF-0018, on the Salton Sea, is the obvious comparison. There a retelling dropped the USGS’s “most recently formed”, and we rated it Mostly True, because the 1905 accident and the lake it made are real and the adverb corrected a detail beside that core. Here the core is also real: USGS guidance does tell catchment households to disconnect the downpipe. The detail that drifted is which document said so, and on what terms.

The case for Misleading

This file’s first draft rated the sentence Misleading, and the argument deserves setting out. SF-0026’s sentence was an attribution, “The USGS asks residents”, hung on one article, and that article asked nothing of residents in general. It offered the step to the worried, and said the January 2025 fall it was written about usually needed no action. On that reading the dropped condition is the claim, and the verdict standard sends that to Misleading.

It does not hold, because Misleading needs a false conclusion. A reader of SF-0026’s summary would conclude that USGS guidance tells households on catchment water to disconnect the downpipe while material is falling. The USGS’s ash guidance says to do it when ashfall is forecast, and the tephra guidance HVO points to says to do it whenever a fall is possible, Pele’s hair included. The conclusion is right. The attribution is wrong, and the missing reassurance about January 2025 is wrong by omission. That is the Mostly True case.

The verdict’s confidence is moderate, not high. No USGS page read for this file names Pele’s hair in its downpipe advice; the bridge is the article’s “Much of the general guidance”, and the tephra guidance HVO links, which is Sea Grant’s rather than the USGS’s.

The argument for leaving it alone

There is also a case that the sentence needs no verdict against it. The error ran toward caution. Disconnecting a downpipe while Pele’s hair falls “will prevent particles from entering your tank”, and a reader who followed SF-0026 would have done what current guidance advises. The page quoted HVO’s sentence exactly in its body.

All of that is true. But SF-0026 told readers what a particular source said, and that source did not say it. A correction tests what we said, and that is why SF-0026 carries one and why this sentence is not Verified.

What this file does not claim

It does not claim anyone acted on the sentence, or was harmed by it. There is no record of that either way. The page was never posted socially, and the error was found before its first post.

It does not claim the downpipe step was optional. It claims only that the January 2025 article offered the step on a condition, about a fall that article said usually needed no action. The guidance HVO points to today says, for everyone, “If tephra fall is possible”, to disconnect downpipes from catchment tanks and cover them.

It does not claim to know whether a fall is possible where you live today. The eruption has continued. The photograph above, also K. Mulliken’s for the USGS, is from episode 46, in May 2026. HVO’s daily update of 25 September 2026, read for this file the next day, gives Kīlauea’s volcano alert level as WATCH and says “Kīlauea has been erupting episodically since December 23, 2024”. It reports overflows from the north vent since 22 September, and says another fountain event cannot be forecast with certainty, “although conditions remain favorable”. Its summary of episode 54, on 25 August 2026, says HVO received “a report of trace Pele’s hair falling in the Ka‘ū district”. Its advice on these fragments is: “Residents and visitors should minimize exposure to these fragments, which can cause skin, eye, and respiratory irritation”, and it points to the tephra guidance quoted above. If you are on catchment water near Kīlauea, the place to ask is the Hawaiian Volcano Observatory, at usgs.gov/volcanoes/kilauea or askHVO@usgs.gov, not this file or the last one.

And it does not claim the rest of SF-0026 was careless. An earlier review caught two details that had drifted onto the wrong volcano and into the wrong place, and fixed them before publication. This one got past that review. The change the correction records is specific: a page that a social post will link to is now re-read against its primary source, by someone who did not write it, before the post goes out. That check is what found this.

The evidence

  1. The advice exists, in HVO's words, with the timing condition SF-0026 kept: "Disconnect the downpipe that connects your gutter system to your tank when Pele's Hair is falling. This will prevent particles from entering your tank."

    Supports the claimdecisive

    S1

  2. The advice is offered on a condition SF-0026 dropped: "However, if you are concerned about Pele's Hair getting in your water catchment system during future lava fountain episodes, there are steps you can take to prevent that from happening."

    Contradicts the claimdecisive

    S1

  3. For the fall it describes, HVO says action was usually unnecessary: "The recent eruption episode deposited less than 1 millimeter (a fraction of an inch) of Pele's Hair in communities near Kīlauea's summit. This amount usually does not require any action".

    Contradicts the claimdecisive

    S1

  4. On catchment water specifically, the sentence immediately before the condition: "The amount of Pele's Hair that fell recently was small enough to be handled by most general filtration systems." SF-0026 as published did not carry this sentence anywhere.

    Contradicts the claimdecisive

    S1

  5. The whole passage is framed as an answer to residents' questions rather than as an order: "You may be wondering if there are steps you need to take regarding vehicles, pets and children being outside, grazing livestock, or water catchment systems if you live in an area that has been affected by Pele's Hair."

    Contradicts the claimstrong

    S1

  6. USGS general ash guidance gives the step to everyone, before the fall. Under "Key Actions for Everyone in an Ashfall", "If ashfall is forecast:": "Disconnect downpipes from roof catchment rainwater tanks to keep ash out." And on water supply: "For roof catchment rainwater systems, we advise disconnecting the downpipe from the roof to the tank prior to the ashfall." Both pages are about ash. S1 says "Much of the general guidance about volcanic ash exposure and cleanup can be applied to Pele's Hair, though the two are not exactly the same."

    Supports the claimstrong

    S6S7S1

  7. The roof-catchment page S1 links at "water catchment system" says these systems "are very vulnerable to contamination by volcanic ashfall because of the high ratio between the collection area and the volume of the tank", and: "If you have ash on your roof and you did not disconnect your downpipe from your rainwater tank, disconnect the downpipe now to protect your tank water." It goes on: "If there is ash in your rainwater tank, use your emergency water for drinking and preparing food until official advice is provided, based on the results of volcanic ash analysis and/or water testing." It also says, in full: "Tank water contaminated by ash is unlikely to be a health hazard as elements released from the ash (particularly iron, manganese and aluminium) can impart an unpleasant metallic taste to the water making it unpalatable to drink, with this effect outweighing the release of any toxic elements such as fluorine from the ash." And: "In most cases, small amounts of ash (a few mm) are unlikely to make water unsafe to drink but may give the water an unpleasant metallic or sour taste."

    Supports the claimstrong

    S4

  8. HVO's current daily update points readers to tephra guidance that names Pele's hair and gives the step to everyone when a fall is possible. S5 lists "Pele's hair" among tephra and ends its tephra advice: "More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/". That guidance (S8) says tephra "includes glassy lava fragments, frothy lava called reticulite, and Pele's hair", and under "GENERAL ADVICE FOR EVERYONE DURING TEPHRA FALL", "If tephra fall is possible:": "Disconnect downpipes from roof catchment tanks to keep tephra out." For catchment households: "To prevent contamination of your tank water, cover the water tank with a tarp and disconnect the downpipe." On drinking water it gives the risk and its usual scale together: "Contamination of drinking water by tephra fall can occur. This can lower the pH to undesirable levels and potentially toxic elements can leach from the tephra." And, next: "Small amounts of tephra fall (several millimeters in thickness) are unlikely to render water unsafe for consumption, although the water may develop an unpleasant metallic or sour taste." S8 is published by University of Hawaiʻi Sea Grant, not the USGS; it is cited as the guidance HVO directs readers to.

    Supports the claimstrong

    S5S8

  9. The episode. HVO places the fall in "episode 4, from January 15–18, there were no tradewinds". The same article reports that the eruption "ended its 5th episode at 4:30 AM HST January 23" and that "Five fountaining episodes have taken place so far". SF-0026 said HVO gave the January dates as "the fifth of five fountaining episodes".

    Contextdecisive

    S1

  10. The three hedges. Strand size in S1: "These golden strands can be more than a meter (3 feet) long and less than 1 millimeter (0.04 inches) thick." In S2: "Pele's hairs can be more than 1 meter (3 feet) long and are often less than 1 millimeter (0.04 inches) thick." The tangles: "In some areas, the hair tangled into tumble-weed like structures up to 60 cm (about two feet) long." SF-0026's hook dropped "can be", its body dropped "often", and its summary dropped "in some areas".

    Contextdecisive

    S1S2

  11. None of this touches what SF-0026 actually tested. HVO states, of Kīlauea's own fountaining, that the strands "can be more than a meter (3 feet) long and less than 1 millimeter (0.04 inches) thick", that with no tradewinds they fell on named communities, and that in some areas they tangled into structures up to 60 cm long. The mechanism is S2's: "Like the thinning strings that form when you pull your hands away from sticky dough, the hair strands form when blobs of lava are torn apart and the fluid lava still connecting them is stretched thin."

    Contextdecisive

    S1S2

Evidence that cuts the other way

Findings that complicate or argue against the verdict above. They are listed because leaving them out would make the file look stronger than it is.

  1. The case for Misleading. SF-0026's sentence was an attribution, "The USGS asks residents", and the one source it was attributed to asked nothing of residents in general: it offered the step "if you are concerned about Pele's Hair getting in your water catchment system during future lava fountain episodes", and said the fall it was written about "usually does not require any action". On that reading the dropped condition is the claim, which the verdict standard sends to Misleading, and this file's first draft said so. This file's answer is that Misleading needs a false conclusion, and the conclusion a reader would draw, that USGS guidance tells catchment households to disconnect while material is falling, is supported by S6, S7 and the guidance HVO points to (S8). What is false is which document said it, and on what terms.

    Contradicts the claimstrong

    S1

  2. The USGS pages that give the step unconditionally are about ash, not Pele's hair, and S1 does not say which parts of the ash guidance apply. The roof-catchment page (S4) is conditioned on ash already on the roof. No USGS page read for this file names Pele's hair in its downpipe advice; the guidance that does (S8) is Sea Grant's. This is why the verdict's confidence is moderate, not high. It does not carry the verdict to Misleading, because S6 and S7 give the step before a fall and S8, which HVO links, applies it to tephra including Pele's hair.

    Contradicts the claimsuggestive

    S4S6S7S8S1

  3. The error ran toward caution. Disconnecting a downpipe while Pele's hair falls is what HVO describes, it "will prevent particles from entering your tank", and a reader who did it would have done what current guidance advises. On that view the sentence needs no verdict against it at all. This file's answer is that SF-0026 told readers what a specific source said, and that source did not say it; a correction tests what we said, not only what a reader would do.

    Supports the claimstrong

    S1S8

  4. The page did carry HVO's own sentence, verbatim, in the body, including "when Pele's Hair is falling". A reader who reached the quotation had the agency's words in front of them. What they did not have was the sentence before it, and a reader who stopped at the summary had neither.

    Supports the claimstrong

    S1

  5. HVO itself frames the subject as a hazard. The article's title is about Pele's hair hazards; it says "Both Pele's Hair and volcanic ash are abrasive and can irritate eyes, skin, and respiratory systems"; and it looks forward: "it's good to be aware and prepared in case more Pele's Hair falls in the future or accumulates over time", with monitoring data suggesting "this type of activity could continue". A reader who took from SF-0026 that the fibre is something to guard against took something HVO also says. What the article does not say is that the January 2025 fall required every household on catchment water to act.

    Supports the claimstrong

    S1

  6. SF-0026 did report the small quantity. As published, one of its evidence findings said: "Quantities are small even when the extent is large. The recent episode deposited 'less than 1 millimeter (a fraction of an inch) of Pele's Hair in communities'. Wide distribution and thin deposition are both true, and reporting only the first would overstate it." Its body said the recent episode left "less than 1 millimeter" of it, and that "a file that reported only the tumbleweeds would be overselling a real thing". A reader of the whole page had the quantity. The page never connected it to the water advice, and a reader of the summary had neither.

    Supports the claimsuggestive

    S1

What we still don’t know

  • Whether anyone acted on the sentence. This file has no record of how many people read SF-0026 between 7 August and 25 September 2026, or whether any of them was on catchment water near Kīlauea. The page was never posted socially. The harm, if any, is unknown, and this file does not estimate it.
  • How the episode error happened. SF-0026 said HVO gave the January dates as "the fifth of five fountaining episodes beginning 23 December 2024 and ending 23 January 2025". The article mentions the fifth episode twice, both times about 23 January, and names episode 4 once, in the sentence that dates the fall. That is where the slip could have come from. It is not established that it did.
  • What applies to a given fall. The January 2025 article's downpipe passage was written about a deposit of under a millimetre, and offered the step for "future lava fountain episodes". The eruption has continued. HVO's daily update of 25 September 2026 (S5), read on 26 September, gives the volcano alert level as WATCH, says "Kīlauea has been erupting episodically since December 23, 2024", and reports precursory overflows from the north vent since 22 September; it says a further fountain event cannot be forecast with certainty, "although conditions remain favorable". Its advice on tephra, Pele's hair included, is: "Residents and visitors should minimize exposure to these fragments, which can cause skin, eye, and respiratory irritation. More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/". That guidance (S8), published by University of Hawaiʻi Sea Grant, tells everyone, "If tephra fall is possible:", to "Disconnect downpipes from roof catchment tanks to keep tephra out", and to cover the tanks. What this file cannot say is whether a fall is possible where a given reader lives on a given day. A reader on catchment water near Kīlauea should check HVO, at https://www.usgs.gov/volcanoes/kilauea or askHVO@usgs.gov, and follow the guidance it points to and any instructions from Hawaiʻi County Civil Defense, not either file.
  • How much of the USGS's ash guidance applies to Pele's hair. S1 says "Much of the general guidance about volcanic ash exposure and cleanup can be applied to Pele's Hair, though the two are not exactly the same", and does not say which parts. The USGS pages that give the downpipe step (S4, S6, S7) are written for ash and do not name Pele's hair. The guidance HVO now points to (S8) does apply the step to tephra, Pele's hair included, but it is Sea Grant's publication, not the USGS's. This file treats the downpipe step as applying to Pele's hair on that combined basis, which is the judgement behind the verdict's moderate confidence.
  • SF-0026's claim statement still describes the strands as "over a metre long, thinner than a millimetre", without HVO's "can be" or "often". This file reads that as a claim that such strands exist, which HVO supports, rather than a claim that every strand is that size, which it does not. SF-0026's correction changed the hook, the body, the image caption, the share line and the card on exactly this point; its correction entry names the hook, the card and the share line. The claim statement was left as a statement of the claim under test. A reader who takes it the second way is owed the same qualifier.
  • Every source but one is the USGS, and most are the Hawaiian Volcano Observatory. For a file whose claim is "the USGS says X", that is the right source; it is still one voice. S8 is the exception: Sea Grant's guidance, cited because HVO points readers to it, and attributed to its publisher.

Sources

Every source below was read in full before it was cited. Archive snapshots are recorded at research time, because a file whose sources have evaporated is indistinguishable from one that never had any.

  1. S1Tier 1Read in full

    Volcano Watch — Recent lava fountains highlight Pele's Hair hazards

    US Geological Survey, Hawaiian Volcano Observatory · 2025-01-23

    The whole of the reopened claim. The downpipe advice and the condition it is offered on; the statement that the January 2025 deposit "usually does not require any action"; the filtration sentence; the question-and-answer framing of the passage; the episode number for the fall on the named communities; and the "can be" and "In some areas" hedges. SF-0026's S2. Read in full on 2026-09-25, live and in the 2025-12-07 archive capture. The article text is identical in both, so the page is the same before and after SF-0026 cited it, and the error cannot be put down to a revision on HVO's side.

    Accessed 2026-09-25Archived copy

  2. S2Tier 1Read in full

    Volcano Watch — Pele's hairs: a beautiful hazard on the Island of Hawaiʻi

    US Geological Survey, Hawaiian Volcano Observatory · 2023-03-23

    The "often" on strand thickness, which SF-0026's body dropped, and the formation mechanism that SF-0026's verdict rests on. It says nothing about water tanks or downpipes; the advice comes from S1 alone. SF-0026's S1. Read in full on 2026-09-25, live and in the 2026-01-07 archive capture, and the quoted passages are identical in both. Not independent of S1: the same observatory's newsletter.

    Accessed 2026-09-25Archived copy

  3. S3Tier 1Read in full

    May 5, 2026 — Episode 46 Pele's hair (USGS media library item)

    K. Mulliken · US Geological Survey, Hawaiian Volcano Observatory · 2026-05-05

    This file's photograph and its rights record only: the original caption, the credit line "USGS photo by K. Mulliken.", and the item-level public-domain statement. It says nothing about the downpipe advice and is not cited for it. SF-0026's S3.

    Accessed 2026-09-25Archived copy

  4. S4Tier 1Read in full

    Impacts & Mitigation — Roof Catchment Tanks

    US Geological Survey, volcanic ash impacts website · 2022-12-11

    The USGS's household guidance for roof-catchment tanks under volcanic ashfall: that such systems are "very vulnerable to contamination by volcanic ashfall"; the instruction to disconnect the downpipe "now" if ash is on the roof; emergency water for drinking and cooking if ash is in the tank; and that ash-contaminated tank water is "unlikely to be a health hazard" because the metallic taste of the iron, manganese and aluminium released from the ash makes it unpalatable to drink, "with this effect outweighing the release of any toxic elements such as fluorine from the ash". It is about ash, and does not mention Pele's hair. Not cited by SF-0026. It is the page S1 links at the words "water catchment system", added after an independent review found it unread. Read on 2026-09-26, live and in the 2025-03-06 archive capture. The two are byte-identical (sha1 5632b147…), and the page is marked "Page modified: 2022-12-11". The date is that marking. Re-fetched on 2026-09-27, still sha1 5632b147…, to quote the "unlikely to be a health hazard" sentence in full.

    Accessed 2026-09-26Archived copy

  5. S5Tier 1Read in full

    Hawaiian Volcano Observatory Daily Update, Kīlauea, 25 September 2026

    US Geological Survey, Hawaiian Volcano Observatory · 2026-09-25

    The eruption's status at this file's date, and nothing about SF-0026 or January 2025. The update, issued 25 September 2026 at 9:24 AM HST and the latest HVO daily update listed when read on 2026-09-26, gives the volcano alert level as WATCH and the aviation colour code as ORANGE. It says "Kīlauea has been erupting episodically since December 23, 2024", describes episode 54 on 25 August 2026, and says HVO received "a report of trace Pele's hair falling in the Ka‘ū district". It reports precursory overflows from the north vent since the night of 22 September, and says "it is not possible to say with certainty that this activity will lead to the onset of another fountain event at this time although conditions remain favorable". Its tephra advice, which names Pele's hair, is quoted in the uncertainties, and ends: "More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/". That pointer is why S8 is cited. Re-read on 2026-09-26 for the pointer and the activity paragraphs. HVO's Kīlauea page, https://www.usgs.gov/volcanoes/kilauea, read the same day, showed the same alert level, dated 2026-09-25.

    Accessed 2026-09-26

  6. S6Tier 1Read in full

    Impacts & Mitigation — For Public

    US Geological Survey, volcanic ash impacts website · 2023-01-10

    The USGS's quick-start household guidance for ashfall, addressed to everyone. Under "Key Actions for Everyone in an Ashfall", "If ashfall is forecast:": "Disconnect downpipes from roof catchment rainwater tanks to keep ash out." After the fall: "If there is ash in your water, let it settle and then use the clear water. Water contaminated by ash will usually make drinking water unpalatable before it presents a health risk." It is about ash, and does not mention Pele's hair. Not cited by SF-0026 and not linked from S1; found by the fresh-eyes review of 2026-09-26. Read in full on 2026-09-26 with curl and a full Chrome user agent, live and in the 2026-06-11 archive capture. The text from "Key Actions for Everyone in an Ashfall" to the page's modification line is identical in both after whitespace normalisation. The page is marked "Page modified: 2023-01-10"; the date is that marking.

    Accessed 2026-09-26Archived copy

  7. S7Tier 1Read in full

    Impacts & Mitigation — Water Supply: Mitigating measures

    US Geological Survey, volcanic ash impacts website · 2022-12-11

    The USGS's mitigation advice for household roof-catchment supplies under ashfall: "For roof catchment rainwater systems, we advise disconnecting the downpipe from the roof to the tank prior to the ashfall. Tank water contaminated with ash is unlikely to be a health hazard, but will probably have an unpleasant metallic taste, so it may be necessary to empty, clean and refill the tank." It is about ash, and does not mention Pele's hair. Not cited by SF-0026 and not linked from S1; found by the fresh-eyes review of 2026-09-26. Read in full on 2026-09-26 by the same means, live and in the 2025-12-08 archive capture; the roof-catchment paragraph and the modification line are identical in both. The page is marked "Page modified: 2022-12-11"; the date is that marking.

    Accessed 2026-09-26Archived copy

  8. S8Tier 1Read in full

    Resource and Guidance for Volcanic Tephra Fall

    University of Hawaiʻi Sea Grant College Program · 2026-02-20

    The tephra-fall guidance HVO's daily update (S5) directs readers to. It says tephra "includes glassy lava fragments, frothy lava called reticulite, and Pele's hair". Under "GENERAL ADVICE FOR EVERYONE DURING TEPHRA FALL", "If tephra fall is possible:": "Disconnect downpipes from roof catchment tanks to keep tephra out. Cover the tanks (see Specific Guidance for Water Catchment Systems below)." Under "SPECIFIC GUIDANCE FOR WATER CATCHMENT SYSTEMS": "To prevent contamination of your tank water, cover the water tank with a tarp and disconnect the downpipe." And: "If tephra has entered your rainwater tank, consider using your emergency water rather than your tank water supply for drinking and food preparation until official guidance is issued and/or there has been water quality testing." On drinking water it states the risk and its usual scale in consecutive points: "Contamination of drinking water by tephra fall can occur. This can lower the pH to undesirable levels and potentially toxic elements can leach from the tephra." And: "Small amounts of tephra fall (several millimeters in thickness) are unlikely to render water unsafe for consumption, although the water may develop an unpleasant metallic or sour taste." Provenance. S5 links the landing page https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/, which links this PDF; the quotations are from the PDF. The PDF is hosted by University of Hawaiʻi Sea Grant, its document properties name Hawaii Sea Grant, and its cover carries the logos of the Hawaiʻi County Civil Defense Agency, University of Hawaiʻi Sea Grant and the USGS. This file attributes it to Sea Grant as publisher and does not attribute its words to the USGS or HVO. It is cited for what the guidance HVO points to says, not as a USGS statement. Read in full on 2026-09-26. Pages 5 and 6, which carry every quotation above except the definition of tephra, and the cover and back page, were rendered at 110 dpi and read from the image; the text layer was used for the rest. The two drinking-water quotations added on 2026-09-27 are on page 6 and were read from a 130 dpi render of the same file (sha256 unchanged) that day. The date is the PDF's creation date, 2026-02-20; no publication date is printed. The live PDF and the 2026-03-18 archive capture are byte-identical (sha256 b2a7fc06…a28bc8), and pages 5 and 6 render pixel-identical.

    Accessed 2026-09-26Archived copy

How we checked this

What we went looking for, and what we found

This file tests SF-0026's own sentence against the three sources SF-0026 cited, the USGS page the cited article links at the words in dispute (S4), two further pages of the USGS volcanic ash impacts website (S6, S7), and the tephra guidance HVO's current daily update links (S8).

First, whether USGS or HVO-linked guidance gives the downpipe advice unconditionally. In HVO's articles it does not: the advice appears once, in S1, immediately after "if you are concerned". S2 has no water-supply content at all (it uses "water" once, in a comparison with fluid lava) and does not mention tanks, gutters or downpipes; S3 is a photograph. But the USGS ash guidance does. S6, addressed to everyone, says "If ashfall is forecast:" to "Disconnect downpipes from roof catchment rainwater tanks to keep ash out"; S7 advises "disconnecting the downpipe from the roof to the tank prior to the ashfall"; S4 says to disconnect "now" if ash is on the roof. And S8, the guidance S5 points to, gives the step to everyone "If tephra fall is possible", with Pele's hair counted as tephra. This file's first draft read none of these; the second read only S4. Reviewers found them. The USGS ash site's preparedness page was also read on 2026-09-26: its general principle is to "Keep ash out of buildings, machinery, vehicles, downspouts, water supplies, and wastewater systems ... as much as possible", with no specific downpipe instruction, and it is not cited.

Second, whether the verdict should be Misleading, as the first draft had it. That draft's argument, that the dropped condition is the claim, is recorded as contradicting evidence. It is not accepted, because Misleading needs a false conclusion, and the conclusion a reader of SF-0026's summary would draw is supported by S6, S7 and S8. What is wrong is the attribution to S1 and the omission of S1's reassurance about January 2025, which the verdict standard treats as Mostly True. SF-0018's Mostly True, for a dropped USGS qualifier, was checked for consistency.

Third, whether the sentence was the "good-faith simplification that misleads nobody" the verdict standard excludes, which would argue for no verdict against it. The strongest form is recorded as contradicting evidence: the error ran toward caution, and doing what the page said is what current guidance advises. It is not accepted, because SF-0026 told readers what a specific source said, and that source did not say it.

Fourth, whether any source had been revised. S1 and S2 were read live on 2026-09-25 and compared with their archive captures of 2025-12-07 and 2026-01-07. The passages quoted here are identical in both, so the discrepancy is SF-0026's and not a later change at source. S4, read live on 2026-09-26, is byte-identical to its capture of 2025-03-06. The quoted passages of S6 and S7 match their captures of 2026-06-11 and 2025-12-08. S8 is byte-identical to its capture of 2026-03-18.

Fifth, the eruption's current status, because the file tells readers where to go. HVO's daily update of 25 September 2026 (S5) and its Kīlauea page were read on 2026-09-26. S4 to S8 are the only sources added beyond SF-0026's own.

  • We searched for evidence against our own conclusion
  • We traced where the claim started
  • The claim is stated in its strongest form, not a weak version
  • The photograph was verified independently of the story
  • We checked whether this was settled after the popular version froze
  • Image rights were traced to a stated licence
  • We checked what we were leaving out
  • The verdict sat before publication, and was re-read cold
Confidence in the verdict
moderate
Verdict assigned
Most recent authoritative source
Researched by
The Strange File
Second reviewer
ChatGPT Health/Sensitivity Review

This is the same set of checks on every file. How we verify things.

Part of a collection

The Qualifier Is The StoryFile 5 of 9The interesting content is in the clause everyone skims.

The other Case Reopened file owed under the same ruling (D-059). Both reopen a file of ours rather than a popular claim: here a USGS article's condition was dropped from its advice, there an inference about the tube's reuse was written as the patent's own words.

The same kind of failure, committed by the other party: there the popular version dropped a USGS qualifier ("most recently formed") and the file restored it; here this publication dropped the qualifier from a USGS article itself. Both are Mostly True: in each the core holds and the dropped qualifier is the identified detail.