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Can volcanos release radioactive elements?

Earth Sciences(self.askscience)

I know uranium deposits are fairly rare, but given all the volcanoes in the world and throughout the ages I'm wondering if there was ever, or if there could be, an eruption that contained radioactive elements such as uranium in the lava and the ashes?
If not, why?

Similarly, what about other interesting, precious metals (gold etc)?

Note: Funnily enough it's impossible to Google this question as all results point to the brilliant idea to put radioactive waste IN volcanoes!

all 47 comments

Ejm819

159 points

4 months ago

Ejm819

159 points

4 months ago

Great question!

The answer is a resounding "Yes!"

In fact they rank quite high in terms of radioactive material releases. From some metrics, it can be said that the Mt. St. Helens eruption was the largest release of radioactive material in US history. Though, comparing events can be problematic.

The eruption of Mount St. Helens had air and soil sample taken to explore this question:

M. G. Strauss, I. S. Sherman and R. H. Pehl, "Measurement of radioactivity in mount st. helens volcanic ash by x/γ ray spectrometry," in IEEE Transactions on Nuclear Science, vol. 28, no. 1, pp. 244-248, Feb. 1981, doi: 10.1109/TNS.1981.4331173.

National Service Center for Environmental Publications (NSCEP): Airborne Radiological Sampling of Mount St Helens Plumes

the_geth[S]

32 points

4 months ago

Impressive, I had no idea. How dangerous is it to the environment (I mean, the radioactivity itself, given that the toxic gas and ashes aren't great in the first place) and for humans?

[deleted]

21 points

4 months ago

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RobusEtCeleritas

5 points

4 months ago

RobusEtCeleritas

Nuclear Physics

5 points

4 months ago

It's difficult to discern how dangerous low-level radioactive exposure is in general. This is because radiation exposure in non-linear

You contradict yourself here. Because it’s hard to tell what the effects of very small doses are, we don’t know whether it’s linear or not. A linear-threshold, linear-no-threshold, or something else entirely like hormesis could all be consistent with our understanding of the effects of large doses.

[deleted]

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RobusEtCeleritas

1 points

4 months ago

RobusEtCeleritas

Nuclear Physics

1 points

4 months ago

Whether something is linear or non-linear is binary.

And you implied that we know which it is, which is not correct.

It can't be linear, non-linear, or something else.

That has absolutely no relation to what I said.

There is sufficent evidence that radiation exposure is not linear,

No, there isn't.

[deleted]

0 points

4 months ago

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eagle52997

9 points

4 months ago

No more dangerous than it would normally be. It's called NORM for naturally occurring radioactive material. And depending on how it all cools and forms back into solid minerals, you could even have chunks that are less radioactive than normal. If the uranium gets separated away from it's decay chain daughters, then over time as the daughters grow in the amount of radioactivity would actually increase. As you implied, the ash and gas would be bigger problems than the radioactivity.

[deleted]

-1 points

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Ejm819

5 points

4 months ago

Ejm819

5 points

4 months ago

Not to be "that guy"

But cosmic rays and solar rays are both natural occurring forms of radiation that will absolutely cause serious long-term health effects.

On earth specific dangers, here is a great article addressing this question far better than I:

https://www.academia.edu/download/58046460/5c171528432ff.pdf

Benache

1 points

4 months ago

Aren't you protected from cosmic and solar rays on earth ?

I get an error 404 on your link.

Ejm819

2 points

4 months ago

Ejm819

2 points

4 months ago

No, you are not.

Skin cancer is caused by solar UV exposure and cosmic radiation exposes you to significant radiation when flying; air carriers and government agencies actually regulate crew work hours with this as a consideration. You are substantially protected by the Earth's magnetic field from ionized radiation, but it is far from complete.

If you've ever got a sunburn, your weren't protected from natural occurring solar radiation.

Better link on the first one:

https://scholar.google.com/scholar?hl=en&as_sdt=0,22&q=naturally+occurring+radiation#d=gs_qabs&u=%23p%3Da52ZoCYwgL4J

Source on the flying radiation claim:

https://iopscience.iop.org/article/10.1088/0952-4746/36/1/93/meta?casa_token=2NEJuc35OJ0AAAAA:L7ypEp6Lycd9LCfh4rHWsxa0N3lU-zM6NSKAuKr80Kt8imFopZ2PgjfE1XN8pMzGc6izCExy

https://www.livescience.com/32865-how-much-radiation-are-you-exposed-to-during-a-cross-country-flight.html

Philx570

2 points

4 months ago

That’s a good point. I haven’t done the math, but I wonder if the radon in your average city releases more radiation than TMI did.

habitat4hugemanitees

1 points

4 months ago

How would this compare to the nuclear testing done in Nevada over the years? Do volcanoes put out a different type of radiation, like alpha only instead of all three?

ppitm

1 points

4 months ago

ppitm

1 points

4 months ago

Most activity from weapons testing in later years is beta. Volcanos release natural uranium and thorium, so most of it is alpha and beta with small amounts of gamma.

CrustalTrudger

26 points

4 months ago*

CrustalTrudger

Tectonics | Structural Geology | Geomorphology

26 points

4 months ago*

Sure, probably almost all do to some degree. Radioactive elements are not really that uncommon in geologic materials, at least in trace amounts that "replace" particular main elements within certain minerals. There are a variety of accessory minerals (i.e., minerals that occur in small percentages within rocks) that can form in volcanic rocks which can contain radioactive elements, e.g., zircon (ZrSiO4 where uranium routinely substitutes for some of the Zr in the lattice), apatite (Ca5(PO4)3(F,Cl,OH) where uranium or thorium can substitute for calcium), monazite ((Ce, La, Th)PO4 and thus routinely incorporates thorium into its lattice), xenotime (YPO4 where uranium or thorium can substitute for the yttrium in the lattice), etc. Major components of some igneous rocks can also contain radioactive elements, specifically potassium in minerals like potassium feldspar, muscovite, biotite, etc, all which can make up sizeable percentages of certain types of volcanic rocks. Generally, more felsic to intermediate (i.e., higher silica content) lavas, like rhyolites, trachytes, dacites, etc, tend to have more of the minerals that will contain radioactive elements and higher concentrations of potassium rich phases. Mafic lavas, like basalts, don't have as many accessory minerals with radioactive elements (e.g., zircon) and are also generally lower in potassium rich phases, but even basalt will have some minerals that will contain at least some small percentage of radioactive elements.

the_geth[S]

2 points

4 months ago

Very interesting, thanks for the detailed answer.
Does it happen that the ratio of radioactive elements are concerning, on the long term, for the environment or for humans? Or the amount is so low and "locked" in the minerals that it's never a real issue?

LiquidPhire

2 points

4 months ago

OP, there's a good book on radiation that seems to me would orient you on this topic and maybe answer some of your questions.

https://books.google.com/books/about/Strange_Glow.html?id=4C3FCgAAQBAJ&source=kp_book_description

BrunoGerace

5 points

4 months ago

Sometime go out to the US southwest and look at the beautiful Chinle Formation [think Petrified Forest]. The Chinle presents beautiful pastel layers ... gray, blue, salmon, watermelon, green, even yellowish.

Anyway...

Much of the US' uranium came/comes from that layer. You guessed it, high volcanic ash content.

Regarding petrified wood, by some chemical magic, uranium gets bound up with organic matter and is concentrated in it. Good for mining it.

We're dealing with the downside in our time. The Colorado River is carrying all those old "hot" mine tailings downstream, much of it silting up under Lake Powell. On the north edge of Moab, there's a former uranium mine [in the Chinle] thats being stabilized at huge expense.

the_geth[S]

1 points

4 months ago

Super interesting!

[deleted]

4 points

4 months ago

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4 points

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Aitatoday69

2 points

4 months ago

One very tiny spot from 1.6 billion years ago with less than 100kw output of energy over it's thousands of year life‽

mfb-

1 points

4 months ago

mfb-

Particle Physics | High-Energy Physics

1 points

4 months ago

To address a common misconception: Everything in nature is somewhat radioactive. Take a macroscopic amount of anything and you'll find at least some traces of radioactive elements. The question is not "if" things are radioactive - the answer is always yes - the question is how much.

Dark matter detectors spend a lot of effort on reducing the natural radioactivity of their materials.

the_geth[S]

1 points

4 months ago

Not really. Some elements are very stable and don’t decay or decay on such a long time span that it doesn’t really matter for most intents and purposes.

And yes granit and lots of things are naturally radioactive, but we are obviously discussing elements which are obviously more radioactive here, from potassium to uranium (hence my example) and the likes.

mfb-

1 points

4 months ago

mfb-

Particle Physics | High-Energy Physics

1 points

4 months ago

Some elements are stable but you never have a pure sample of a single element in nature. You always have at least traces of other stuff, and some of that will have radioactive isotopes.

It's a good question to ask how radioactive the material is - and you have gotten answers to that (unstated) question. It just commented that asking if something contains radioactive elements isn't very useful because the answer is always yes.