Scientists to Io: Your volcanoes are in the wrong place

Apr 04, 2013

This five-frame sequence of images from NASA's New Horizons mission captures the giant plume from Io's Tvashtar volcano. Snapped by the probe's Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Jupiter in 2007, this first-ever movie of an Io plume clearly shows motion in the cloud of volcanic debris, which extends 330 km (205 miles) above the moon's surface. Only the upper part of the plume is visible from this vantage point. The plume's source is 130 km (80 miles) below the edge of Io's disk, on the far side of the moon. Io's hyperactive nature is emphasized by the fact that two other volcanic plumes are also visible off the edge of Io's disk: Masubi at the 7 o'clock position, and a very faint plume, possibly from the volcano Zal, at the 10 o'clock position. Jupiter illuminates the night side of Io, and the most prominent feature visible on the disk is the dark horseshoe shape of the volcano Loki, likely an enormous lava lake. Boosaule Mons, which at 18 km (11 miles) is the highest mountain on Io and one of the highest mountains in the solar system, pokes above the edge of the disk on the right side. The five images were obtained over an 8-minute span, with two minutes between frames, from 23:50 to 23:58 Universal Time on 1 March 2007. Io was 3.8 million km (2.4 million miles) from New Horizons. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

(Phys.org) —Jupiter's moon Io is the most volcanically active world in the Solar System, with hundreds of volcanoes, some erupting lava fountains up to 250 miles high. However, concentrations of volcanic activity are significantly displaced from where they are expected to be based on models that predict how the moon's interior is heated, according to NASA and European Space Agency researchers.

Io is caught in a tug-of-war between Jupiter's massive gravity and the smaller but precisely timed pulls from two neighboring moons that orbit further from Jupiter – Europa and Ganymede. Io orbits faster than these other moons, completing two orbits every time Europa finishes one, and four orbits for each one Ganymede makes. This regular timing means that Io feels the strongest gravitational pull from its neighboring moons in the same orbital location, which distorts Io's orbit into an oval shape. This in turn causes Io to flex as it moves around Jupiter.

For example, as Io gets closer to Jupiter, the giant planet's powerful gravity deforms the moon toward it and then, as Io moves farther away, the gravitational pull decreases and the moon relaxes. The flexing from gravity causes tidal heating—in the same way that you can heat up a spot on a wire coat hanger by repeatedly bending it, the flexing creates friction in Io's interior, which generates the tremendous heat that powers the moon's extreme volcanism.

The question remains regarding exactly how this tidal heating affects the moon's interior. Some propose it heats up the deep interior, but the prevailing view is that most of the heating occurs within a relatively shallow layer under the crust, called the asthenosphere. The asthenosphere is where rock behaves like putty, slowly deforming under heat and pressure.

This is a map of the predicted heat flow at the surface of Io from different tidal heating models. Red areas are where more heat is expected at the surface while blue areas are where less heat is expected. Figure A shows the expected distribution of heat on Io's surface if tidal heating occurred primarily within the deep mantle, and figure B is the surface heat flow pattern expected if heating occurs primarily within the asthenosphere. In the deep mantle scenario, surface heat flow concentrates primarily at the poles, whereas in the asthenospheric heating scenario, surface heat flow concentrates near the equator. Credit: NASA/Christopher Hamilton

"Our analysis supports the prevailing view that most of the heat is generated in the asthenosphere, but we found that volcanic activity is located 30 to 60 degrees East from where we expect it to be," said Christopher Hamilton of the University of Maryland, College Park. Hamilton, who is stationed at NASA's Goddard Space Flight Center in Greenbelt, Md., is lead author of a paper about this research published January 1 in Earth and Planetary Science Letters.

Hamilton and his team performed the spatial analysis using the a new, global geologic map of Io, produced by David Williams of Arizona State University, Tempe, Ariz., and his colleagues using data from NASA spacecraft. The map provides the most comprehensive inventory of Io's volcanoes to date, thereby enabling patterns of volcanism to be explored in unprecedented detail. Assuming that the volcanoes are located above where the most internal heating occurs, the team tested a range of interior models by comparing observed locations of volcanic activity to predicted tidal heating patterns.

"We performed the first rigorous statistical analysis of the distribution of volcanoes in the new global geologic map of Io," says Hamilton. "We found a systematic eastward offset between observed and predicted volcano locations that can't be reconciled with any existing solid body tidal heating models."

Possibilities to explain the offset include a faster than expected rotation for Io, an interior structure that permits magma to travel significant distances from where the most heating occurs to the points where it is able erupt on the surface, or a missing component in existing tidal heating models, like fluid tides from an underground magma ocean, according to the team.

The magnetometer instrument on NASA's Galileo mission detected a magnetic field around Io, suggesting the presence of a global subsurface magma ocean. As Io orbits Jupiter, it moves inside the planet's vast magnetic field. Researchers think this could induce a magnetic field in Io if it had a global ocean of electrically conducting magma.

This is a composite image of Io and Europa taken March 2, 2007 with the New Horizons spacecraft. Here Io (top) steals the show with its beautiful display of volcanic activity. Three volcanic plumes are visible. Most conspicuous is the enormous 300-kilometer (190-mile) high plume from the Tvashtar volcano at the 11 o'clock position on Io's disk. Two much smaller plumes are also visible: that from the volcano Prometheus, at the 9 o'clock position on the edge of Io's disk, and from the volcano Amirani, seen between Prometheus and Tvashtar along Io's terminator (the line dividing day and night). The Tvashtar plume appears blue because of the scattering of light by tiny dust particles ejected by the volcanoes, similar to the blue appearance of smoke. In addition, the contrasting red glow of hot lava can be seen at the source of the Tvashtar plume. This image was taken from a range of 4.6 million kilometers (2.8 million miles) from Io and 3.8 million kilometers (2.4 million miles) from Europa. Although the moons appear close together in this view, a gulf of 790,000 kilometers (490,000 miles) separates them. Io's night side is lit up by light reflected from Jupiter, which is off the frame to the right. Europa's night side is dark, in contrast to Io, because this side of Europa faces away from Jupiter. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

"Our analysis supports a global subsurface magma ocean scenario as one possible explanation for the offset between predicted and observed volcano locations on Io," says Hamilton. "However, Io's magma ocean would not be like the oceans on Earth. Instead of being a completely fluid layer, Io's magma ocean would probably be more like a sponge with at least 20 percent silicate melt within a matrix of slowly deformable rock."

Tidal heating is also thought to be responsible for oceans of liquid water likely to exist beneath the icy crusts of Europa and Saturn's moon Enceladus. Since liquid water is a necessary ingredient for life, some researchers propose that life might exist in these subsurface seas if a useable energy source and a supply of raw materials are present as well. These worlds are far too cold to support liquid water on their surfaces, so a better understanding of how tidal heating works may reveal how it could sustain life in otherwise inhospitable places throughout the Universe.

"The unexpected eastward offset of the volcano locations is a clue that something is missing in our understanding of Io," says Hamilton. "In a way, that's our most important result. Our understanding of tidal heat production and its relationship to surface volcanism is incomplete. The interpretation for why we have the offset and other statistical patterns we observed is open, but I think we've enabled a lot of new questions, which is good."

Io's volcanism is so extensive that it gets completely resurfaced about once every million years or so, actually quite fast compared to the 4.5-billion-year age of the solar system. So in order to know more about Io's past, we have to understand its interior structure better, because its surface is too young to record its full history, according to Hamilton.

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It's already apparent that people decide what to pay attention to in science. The problem is that a failure to carefully listen to critics undermines our own ability to question the models. While it seems popular today amongst science consumers and even pundit journalists to treat science as a team sport, people who actually use science professionally or as a tool in their daily lives to evaluate incoming information recognize bias as a threat to the methodology of science.

What would mainstream science be like if nobody actually questioned it? Would that lead people to believe these complex notions even more? My take is that -- whether you are a science consumer, an experimentalist on the lookout for unexpected inferences, or somebody who is trying to use science as a tool to make better critical decisions -- we all heavily depend upon poignant critics.

Science consumers are free to pretend otherwise, but real science which is accountable both needs and listens to the critics.

Realizing it is ignorant, my first thought was that tomato seeds and juice do not squirt out where you are squeezing the tomato, either.As for opposing views, posting your same pet theories on nearly every article on almost any topic is not educating anyone to your pet theory, it is merely irritating those interested in comments about the article and prevailing science rather than hearing your pet theory once again. Try an OCCASIONAL link and be patient enough to understand those interested will learn, and to the rest maybe some day you can say "told ya so". But NOT every single article! Simple enough?

As for opposing views, posting your same pet theories on nearly every article on almost any topic is not educating anyone to your pet theory, it is merely irritating those interested in comments about the article and prevailing science rather than hearing your pet theory once again. Try an OCCASIONAL link and be patient enough to understand those interested will learn, and to the rest maybe some day you can say "told ya so". But NOT every single article! Simple enough?

I take it "prevailing science" implies whatever most of the scientists believe, or the "standard theory". Each and every article does put forth the "prevailing science" and little else to consider. Take the above for example, the data doesn't support the theory, yet there is no alternative offered other than rivers of magma that mysteriously don't cool, or a magma ocean in a moon slightly larger than our own. "Prevailing science" gets plenty of play, don't be afraid of alternatives.

The most intriguing reason I prefer the EU theory is the wide ranging implications. I post on many articles because of the relevance of the EUT to the many disparate subjects. The EUT has relevance in everything from particle physics to biology to climate/weather to human history/mythology to nearly every object and phenomenon in space. From the submicroscopic to the extra-galactic and everything in between. The EUT offers a more extensive interdisciplinary connectivity than any other theory.

"Today, nothing is more important to the future and credibility of science than liberation from the gravity-driven universe of prior theory. A mistaken supposition has not only prevented intelligent and sincere investigators from seeing what would otherwise be obvious, it has bred indifference to possibilities that could have inspired the sciences for decades."

"Today, nothing is more important to the future and credibility of science than liberation from the gravity-driven universe of prior theory. A mistaken supposition has not only prevented intelligent and sincere investigators from seeing what would otherwise be obvious, it has bred indifference to possibilities that could have inspired the sciences for decades."David Talbott and Wallace Thornhill, Thunderbolts of the Gods

That was written in the 70's. Before the resolution of the neutrino deficiency. Before the advent of space based solar observing. Before the sun's poles werepassed over. Before we got to a comet or asteroid. Before samples of comets and asteroids were returned to earth. Before Deep Impact. Probably before you were born.

Every single item they claimed should happen as we got probes into space, did not happen. Not one. The neutrino deficiency problem was one of their crown jewels, until a non-zero mass neutrino was proposed.

If the theory had been even partially right, it would have opened up a whole new world of physics. Instead, the neutrino flavour problem was solved, and that overthrew particle physics.

Its ok, cantdrive, to look inquisitively at different theories. It is not ok, however, to ignore the advances in science that render such theories to the dustbin of history. You cling to the the EUT the way flat earthers cling to their theory.

In other words, don't just question so called "mainstream". Question your prophets of EU as well.

If the theory had been even partially right, it would have opened up a whole new world of physics.

Yep, and closed the door for thousands of theoretical scientists, and now you know why there is push back from the astrophysical community."When Kepler found his long-cherished belief did not agree with the most precise observation, he accepted the uncomfortable fact. He preferred the hard truth to his dearest illusions; that is the heart of science." Carl Sagan Then again there are your modern scientists where personal limitations, views, and skills would render them jobless if such a theory were to be considered.

Good example on the neutrino problem, let's examine how they "solved" it. According to the "solution", the deficit we observe is due to the flavors changing enroute to the Earth. Now you'd think they'd have come to this conclusion by measurement, but you'd be completely wrong. The measurements take place here on Earth, but tell me, without first measuring the data in the Sun, and along the entire path how could you possibly make such a claim? With flawed logic and a determination to not be out of work that's how. You've got an naïve idealistic view of science, however science shares the ills of the rest of society and humanity. You believe that the scientific method protects science from these ills, but in fact is used to slow the progress in "uncomfortable" fields. Acceptance of the EUT would be so profound and wide reaching, that which would not only affect the sciences but socio-economic/energy structure of the planet, something the current control paradigm is not prepared to alter

"Today, nothing is more important to the future and credibility of science than liberation from the gravity-driven universe of prior theory. A mistaken supposition has not only prevented intelligent and sincere investigators from seeing what would otherwise be obvious, it has bred indifference to possibilities that could have inspired the sciences for decades."

David Talbott and Wallace Thornhill, Thunderbolts of the Gods

What a load of pseudo-intellectual bullshit. It can be put down there with religion as the other load of bullshit. As soon as a title of a book has references to god, gods and mythology, it's credibility is zero.Talbott majored in political science and education, oh yes, I can see the relevance regarding astronomy. Thornhill's contribution was a way of giving Talbott's theories some weight. Apparently Talbott had persuaded Thornhill over a period of 30 days. Chemicals must have been used.

You got quite the ignorant POV, if you knew one iota about 'Thunderbolts of the Gods', you be aware of the context it is used. But that in no way stops you from spouting your drivel. The thing that is lost on the narrow minded pseudo skeptics is the EUT is a multidisciplinary approach that includes speculation in regards to mythology, religion, and human history in addition to the implications it offers in the cosmological, biological, geologic, etc, fields.. As far as I see it, it is the sum of the whole theory that gives it credence. It's a theory in its infancy that has not been properly vetted contrary to popular opinion.

The thing that is lost on the narrow minded pseudo skeptics is the EUT is a multidisciplinary approach that includes speculation in regards to mythology, religion, and human history in addition to the implications it offers in the cosmological, biological, geologic, etc, fields..

You mean it is a pseudo-scientific patchwork of hand-waving, specious argumentation, appeals to authority, commerce driven, anti-scientific, conspiracist Gish gallop, cobbled togeather in such a way as to convince the most gullible and non-critically minded people into spending their cash to buy membership into the elite group of repressed non-scientists who see the light. Or is it lightbulb?

Where does this club meet? What were the dues? Apparently, I didn't get the memo, how I hate to be out of the loop. Or is it circuit? As I said pseudo skeptic. These men are only standing upon the shoulders of those who came before, men like Maxwell, Ampere, Birkeland, Langmuir, Alfven, Bohm, Faraday, Velikovsky, among others. There is no more appeal to authority than what is expected from citing previously described phenomenon, just how science works. If the wheel has been invented, why on earth would you waste your resources to reinvent it? Yet, this is exactly what astrophysicists do, magnetic reconnection and cosmic ray acceleration are two perfect examples where ignorance of previously described physics leads to wasted resources and poorly reinvented hypotheses. What's most ironic about your post is the perfect description you offered for the metaphysical/astrophysical community. It's been shown repeatedly that the graduate programs eliminate most of the critical thinkers.

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