Tag Archives: Volcanism

A new study provides our best-yet prediction of what a metallic volcano might look like

If you like volcanoes, Earth isn’t a bad place to live on. After all, our planet is quite geologically active, and that also translates into a respectable level of volcanism. But when it comes to having a variety of flavors, the Earth can be a bit lacking.

 a) Metallic flow (yellow) emerging from underneath the silicate flow (orange-black) before cooling and b) metallic flow appears gray/silver, with the silicate flow black, after cooling. Image credits A. Soldati et al., (2021), Nature.

A new paper, however, comes to estimate what one type of not-yet-seen volcanic activity might look like. Called ‘ferrovolcanism’, it is likely a hallmark of geologically active worlds whose composition is mainly metallic. The study, although still purely theoretical, could help us better understand some of the more peculiar alien landscapes out there. And even though ‘metal volcanoes’ sounds like something pretty jagged and oppressive-looking, the team’s findings suggest that they’re actually quite mellow.

Metal volcanoes

“Cryovolcanism is volcanic activity on icy worlds, and we’ve seen it happen on Saturn’s moon Enceladus,” says Arianna Soldati, assistant professor of marine, earth and atmospheric sciences at NC State and lead author of a paper describing the work. “But ferrovolcanism, volcanic activity on metallic worlds, hasn’t been observed yet.”

The study, published by researchers at the North Carolina State University, aimed to give us an idea of how volcanic activity would look on a planet made predominantly of metal.

Volcanoes are born when magma, the partially-molten material found beneath a planet’s surface, erupts. The exact nature and behavior of this magma is closely related to the chemical composition of the planet. On Earth, therefore, magmas tend to be mostly molten rock (i.e. silica molecules). On icy worlds, however, magma is in fact a mixture of fluids such as water, ammonia, or methane, all super-chilled.

What the team wanted to find out, however, is how volcanism would look on 16 Psyche, a 140-mile diameter asteroid floating merrily in the asteroid belt between Mars and Jupiter. Infrared and radar analysis of its surface suggests that 16 Psyche is formed mainly of iron and nickel. Even better, though, it’s also the target for an upcoming NASA mission. This inspired Soldati to try and determine what volcanism would look like on the asteroid.

“When we look at images of worlds unlike ours, we still use what happens on Earth—like evidence of volcanic eruptions—to interpret them,” Soldati says. “However, we don’t have widespread metallic volcanism on Earth, so we must imagine what those volcanic processes might look like on other worlds so that we can interpret images correctly.”

The team defined two types of ferrovolcanism that they believe are possible. Type 1, or ‘pure’ ferrovolcanism, occurs on bodies made entirely of metal. Type 2, or ‘spurious’ ferrovolcanism, is what we’re likely to see on bodies that have both rocky and metal elements in their chemical mix.

Together with members of the Syracuse Lava Project, the researchers then simulated the second type, in which metal separates from rock as the magma melts down, in the lab.

“The Lava Project’s furnace is configured for melting rock, so we were working with the metals (mainly iron) that naturally occur within them,” Soldati says. “When you melt rock under the extreme conditions of the furnace, some of the iron will separate out and sink to the bottom since it’s heavier.”

“By completely emptying the furnace, we were able to see how that metal magma behaved compared to the rock one.”

Metallic lava (magma becomes lava once it reaches the surface) can flow up to 10 times faster, and spreads more thinly, than rock lava, the team found. As it flows, this material also separates into an abundance of braided channels, they add. Furthermore, metal lava tended to flow largely beneath the rock one, and emerged at the leading edge of the lava body.

Another important finding of the study is that the thin, braided layers of metallic lava, once cooled, give a distinctive appearance to a planet’s surface. This is very different in nature from those produced by rocky lava flows, Soldati explains, meaning that the two types of volcanism should be easy to spot from afar.

“Although this is a pilot project, there are still some things we can say,” Soldati says. “If there were volcanoes on 16 Psyche—or on another metallic body—they definitely wouldn’t look like the steep-sided Mt. Fuji, an iconic terrestrial volcano. Instead, they would probably have gentle slopes and broad cones. That’s how an iron volcano would be built—thin flows that expand over longer distances.”

The paper “Imagining and constraining ferrovolcanic eruptions and landscapes through large-scale experiments” has been published in the journal Nature Communications.

Some lava-like features on Mars are actually ancient mud flows

For many years, scientists have been puzzled by lava-like flows on the surface of the Red Planet. Turns out that some of these features are actually not caused by lava but by ancient mud flows instead.

Not your typical mud

It’s estimated that there are literally tens of thousands of lava-like landforms on the surface of Mars. Most are situated right in the vicinity of massive channels carved into the crust billions of years ago by fluid flowing downstream.

These channels — which can be hundreds of kilometers in length and dozens of kilometers wide — are believed to be the result of huge floods that caused water to seep into the subsurface, only to reemerge as mud.

In order to test this hypothesis, an international team of researchers simulated Mars-like conditions using the Mars Chamber at the Open University in the UK.

Inside the vacuum chamber, the researchers simulated the release of mud on the Red Planet in analogous conditions of low pressure and frigidly cold temperatures (-20°C). Tweaking the pressure and temperature in such a large vacuum-chamber proved highly challenging, but the authors eventually managed to mimic Mars-like conditions.

Mud flowing from a mud volcano in Azerbaijan. Credit: Petr Brož/Czech Academy of Sciences.

The free-flowing mud didn’t solidify like on Earth because the water began to boil and evaporate, causing the mud to freeze rapidly and form an icy crust.

“The main finding is that mud flows do not behave in the same way on Mars and Earth because of the very great difference in atmospheric pressure. And the difference makes mud flows on Mars have many of the same characteristics as lava flows (on Mars or Earth). This means that we have to be very careful in our interpretation when we see what look, at first sight, like lava flows on Mars,” Lionel Wilson, Emeritus Professor of Earth and Planetary Sciences at Lancaster University, told ZME Science.

Mud vulcanism

The collapsed circular crater of a mud volcano in Azerbaijan. Credit: Petr Brož/Czech Academy of Sciences.

The mud flows formed shapes similar to pahoehoe lava that is frequently encountered in volcanically active regions on Earth, such as Hawaii and Iceland.

Like pahoehoe lava, mud flows in Martian-like conditions solidified in the form of smooth undulating surfaces as liquid ruptured the frozen crust, then refroze.

Mars was no stranger to volcanic eruptions, as its largest mountain, Olympus Mons, attests. This massive Martian volcano towers 16 miles (25 kilometers) above the surrounding plains and stretches across 374 miles (624 km) — roughly the size of the state of Arizona.

However, the new study shows that many geological features on Mars that resemble evidence of volcanic activity may not actually be the result of lava, but rather mud.

“We need to find better ways to distinguish between lava and mud in remote-sensing images (visible, infra-red, and radar). Until then we need to be careful when interpreting images. There is very little doubt about the nature of the lava flows on the flanks of the great martian shield volcanoes, but I am less sure about the “lava flows” in the northern plains of Mars,” Wilson said.

In the future, the team of researchers, which included colleagues from the Institute of Geophysics at the Czech Academy of Sciences, the Rutherford Appleton Laboratory in the UK, CNRS in France, DLR and Münster University in Germany, and CEED in Norway, plan on conducting more experiments involving even larger volumes of mud.

“This reminds us that Mars is as complicated and diverse as the Earth in terms of the processes going on in its interior. And of course everyone wants to know if there was ever life on Mars; life needs water, and if some of what we currently think are lava flows are in fact mud flows, then that implies that early Mars had even more water than we currently think it had,” Wilson concluded.

The findings were reported in the journal Nature Geoscience.

Fossil footprints show how dinosaurs and early mammals fared during massive eruptions

Fossil footprints from the Karoo Basin of southern Africa could teach us more about how ecosystems respond to truly massive volcanic eruptions.

Palaeoenvironmental reconstruction of the Karoo Basin at the Pliensbachian-Toarcian boundary.
Image credits Bordy et al., (2020), PLoS ONE.

The Karoo Basin is covered in extensive basaltic lava flows from the Early Jurassic. It’s believed that the intense volcanic activity recorded during that time had a powerful impact on global climate and local environments, and it largely coincides with a worldwide extinction event.

The floor is lava

“The fossil footprints were discovered within a thick pile of ancient basaltic lava flows that are ~183 million years old,” explains Emese Bordy of the University of Cape Town, lead author of the paper. “The fossil tracks tell a story from our deep past on how continental ecosystems could co-exist with truly giant volcanic events that can only be studied from the geological record, because they do not have modern equivalents, although they can occur in the future of the Earth.”

The basin was turned into a “land of fire” at the onset of the extinction event, the team explains, yet dinosaurs and synapsids still managed to survive in the hellish landscape. Synapsids are a group of animals that include mammals and their closest fossil relatives. Studying their fossils and the fossils of the tracks they left behind might help up understand how ecosystems respond to powerful stresses.

In this study, Bordy and his team described the footprints of these animals, which were fossilized in a sandstone layer deposited between lava flows around 183 million years ago. They reported on five trackways that total 25 footprints among three types of animals — small synapsids, large bipedal and predatory dinosaurs, and smaller, quadrupedal herbivorous dinosaurs. These were some of the very last animals to inhabit the Karoo Basin before it was flooded with lava.

Since the sandstone layer sits in between the deposited lava, it indicates that the animals survived here even after the onset of volcanic activity which transformed the area into a “land of fire”, according to the authors. Further research is needed to find any undiscovered fossils in this area and more accurately date the local geological formations, they add, so we can better track the ecological shifts that took place before and during the extinction.

The paper “Tracking the Pliensbachian-Toarcian Karoo firewalkers: Trackways of quadruped and biped dinosaurs and mammaliaforms” has been published in the journal PLoS ONE.

Bali eruption.

Ancient volcanism shows our emissions can trigger a mass marine extinction

Ancient volcanism offers a glimpse into the future effects of climate change.

Bali eruption.

Volcanic eruption in Bali, Indonesia.
Image credits Alit Suarnegara.

Right now, global climate patterns are swinging wildly (in geological terms), powered by all the greenhouse gases we’re pumping in the atmosphere. We have some broad idea of what these changes will entail, but we don’t know the details — and not knowing what to expect in such circumstances is quite scary. One thing we do know for sure right now is that the high concentrations of carbon dioxide in the atmosphere are draining oceans of oxygen. It’s happening faster than anything similar we’ve ever seen and has researchers worried and scrambling to find solutions.

For that, however, we’ll need to know what to expect. One team of researchers from Florida State University (FSU) dredged the geological record for similar events to use as a guideline. The magnitude and sheer destructiveness of what they found suggests that we were right to worry.

Volca-no

The team used ancient volcanism as a proxy for today’s anthropic emissions. Millions of years ago, during the Toarcian Oceanic Anoxic Event (T-OAE, during the Early Jurassic), powerful eruptions belched large quantities of carbon dioxide into the atmosphere. Oxygen levels in ocean waters soon plummeted. Most marine life followed suit, leading to a devastating mass extinction.

“We want to understand how volcanism, which can be related to modern anthropogenic carbon dioxide release, manifests itself in ocean chemistry and extinction events,” said study co-author Jeremy Owens.

“Could this be a precursor to what we’re seeing today with oxygen loss in our oceans? Will we experience something as catastrophic as this mass extinction event?”

The team set out to reconstruct ocean oxygen levels during the Early Jurassic in order to better understand the mass extinction event during the T-OAE. Their research reinforces previous findings regarding the (bad) effects of increased ocean temperature and acidification on marine life. However, it also revealed the importance of a third factor, oxygen level change, in leading to such an event.

Toarcian paleogeo.

Image credits Scotese CR (2001), Atlas of Earth History via R. Them et al., 2018, PNAS.

For the study, the team retrieved samples of ancient rock formations from North America and Europe. Thallium isotope analysis performed at the FSU-based National High Magnetic Field Laboratory revealed that oxygen levels in the oceans started to drop several hundred thousands of years before the interval we ascribe to the T-OAE. This initial drop was caused by massive bouts of volcanic activity, they explain, adding that it’s not that different a process from modern anthropic emissions of CO2.

“Over the past 50 years, we’ve seen that a significant amount of oxygen has been lost from our modern oceans,” says Theodore Them, a postdoctoral researcher at FSU who led the study. “While the timescales are different, past volcanism and carbon dioxide increases could very well be an analog for present events.”

“As a community, we’ve suggested that sediments deposited during the T-OAE were indicative of widespread oxygen loss in the oceans, but we’ve never had the data until now.”

High atmospheric levels of carbon dioxide increase average temperatures on the planet. This sets into motion multiple chains of events (chemical, biological, as well as hydrological) that compound to remove oxygen from ocean water. Ultimately, this process resulted in severe oceanic deoxygenation and mass extinction of marine life, which we see in the geological record as the T-OAE.

Extinction event

Sequence of events culminating in the Early Jurassic T-OAE. The massive die-off worked to sequester large amounts of carbon (δ13C line) from the atmosphere, allowing conditions to eventually stabilize. Top bars represent biodiversity.
Image credits R. Them et al., 2018, PNAS.

The findings help flesh out our understanding of how Earth’s systems function. But they also point to a worrying precedent. We’re already seeing signs of ocean acidification, increased average temperatures, and of falling levels of oxygen in ocean water. It’s safe to assume that the interplay between these events will have the same results as in the Early Jurassic. Should we continue pumping greenhouse gases such as CO2 in the atmosphere, we might just usher in an ocean mass extinction upon ourselves — one that will likely take society as we know it down, too.

“It’s extremely important to study these past events,” Them said. “It seems that no matter what event we observe in Earth’s history, when we see carbon dioxide concentrations increasing rapidly, the result tends to be very similar: a major or mass extinction event. This is another situation where we can unequivocally link widespread oceanic deoxygenation to a mass extinction.”

Not all is lost, however. All out tech and know-how put us in this position, that’s true, but it also offers the way out. There are steps we can take to stop or at least slow down the rate of oxygen loss in our oceans, the team notes. For example, maintaining environments that absorb and store carbon dioxide (such as wetlands or estuaries) could help reduce the effect of our emissions. The single biggest change we can make, however, is to de-couple our industries and economies from fossil fuels — efforts are already underway, but it never hurts to double down.

Personal efforts also help. Many of the things you can do to reduce your impact on the planet are also quite healthy and beneficial choices on an individual level: drive less, to reduce the level of emissions you put in the air and get some exercise, too. Eat more veggies, cut out as much meat and dairy as you’re comfortable too, or just be more selective about what type of animal protein you eat — good for your health, your wallet, and the planet! Finally, waste not — it helps to reduce emissions from industry, reduces trash, and will give you a mood boost.

The paper “Thallium isotopes reveal protracted anoxia during the Toarcian (Early Jurassic) associated with volcanism, carbon burial, and mass extinction” has been published in the journal Proceedings of the National Academy of Sciences.

Mars’ Arsia Mons and the dinosaurs went extinct at the same time. Coincidence?! Definitely

Here’s a brain teaser: what do the dinosaurs and this giant volcano on Mars have in common? Well, according to NASA research, they may have gone extinct at about the same time.

A digital-image mosaic of Mars’ Tharsis plateau showing Arsia Mons.
Image credits NASA / JPL.

A tad south of Mars’ equator, there’s a rough triangle of wide, softly sloped volcanoes collectively known as the Tharsis Montes. Its southernmost member is named Arsia Mons and, just like its two counterparts, was build by billions of years of lazy lava flows adding on top of one another. We don’t yet have all the details of how its lifecycle looked like, but now we do know when it likely ended — and it’s about the same time as the dinosaurs did.

Gone with the dinosaurs

In its heyday, Arsia Mons spewed out a new lava flow about once every 1 to 3 million years. The last big bout of its activity likely took place in the caldera (the bowl-shaped depression at the top), where scientists found 29 distinct volcanic vents, somewhere around 50 million years ago. This would coincide roughly with the Cretaceous-Paleogene extinction event, which killed off most of the species on Earth at the time, including the dinosaurs.

The caldera itself is a huge thing, measuring some 68 miles (110 kilometers) across. The researchers used high-resolution imaging taken with the Context Camera on the Mars Reconnaissance Orbiter to map the vents and boundaries between successive lava flows in the caldera, and used crater counting to estimate their age. Then they used a computer model developed by Jacob Richardson, a postdoctoral researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and his colleagues from the University of South Florida to determine the order in which each of the 29 vents formed.

The team found that the oldest flows date back to about 200 million years and the youngest between 10 or 90 million years ago. During the peak volcanic activity, they produced collectively produced an estimated 1 to 8 cubic kilometers of magma every million years, adding to the volcano’s height and size.

Arsia Mons.

And it grew pretty big.
Image credits Martin Pauer.

“It’s possible, though, that the last volcanic vent or two might have been active in the past 50 million years, which is very recent in geological terms,” Richardson said.

“Think of it like a slow, leaky faucet of magma. Arsia Mons was creating about one volcanic vent every 1 to 3 million years at the peak, compared to one every 10,000 years or so in similar regions on Earth.”

Understanding Mars’ volcanic activity would allow scientists to peer into the planet’s history and geological structure. A major step towards that goal is to understand the anatomy and lifecycle of these volcanoes, which are dictated by Mars’ internal characteristics and geological processes. And seeing how they behaved on Mars might also help us better understand the volcanoes down on our own planet.

“Mars’ volcanoes show evidence for activity over a larger time span than those on Earth, but their histories of magma production might be quite different,” said Jacob Bleacher, a planetary geologist at Goddard and a co-author on the study.

“This study gives us another clue about how activity at Arsia Mons tailed off and the huge volcano became quiet.”

 

Richardson will be presenting the findings on March 20, 2017, at the Lunar and Planetary Science Conference in The Woodlands, Texas. The study titled “Recurrence rate and magma effusion rate for the latest volcanism on Arsia Mons, Mars” has been published in the journal Earth and Planetary Science Letters.