Tag Archives: supervolcano

A Martian puzzle: is this a supervolcano or an impact crater?

Images from the European Space Agency’s Mars Express mission revealed an extraordinary feature, but the feature poses more questions than it answers: is it the remnant of an ancient supervolcano, or the crater of a meteorite crash?

Perspective view of Ismenia Patera. Image credits: ESA.

Back in 2003, the European Space Agency (ESA) launched Mars Express — a mission with the goal of exploring Mars. More than 14 years later, the orbiter is still providing valuable insight into the Red Planet. Now, it has sent astronomers on Earth pictures of an intriguing feature called Ismenia Patera.

Patera means ‘flat bowl’ in Latin, and it’s as accurate a name as any. Measuring some 75 km across, it has a flat central area, surrounded by a ring of hills, blocks, and lumps of rock which seem to have been ejected from the center. The feature lies in a transition area which lies between Mars’ southern mountains and its northern plains.

Supervolcano or meteorite crater? We don’t really know. The Mars Express view of Ismenia Patera.

The Martian topography is split into two parts: the northern lowland and the southern highlands — the latter being a few kilometers higher. This clear split is an extremely interesting puzzle for researchers, as the cause of this split isn’t really clear. It could be a massive impact, several smaller impacts, tectonic activity, or even supervolcanoes — whatever the reason may be, it remains hidden for now.

Understanding Ismenia Patera could be a much-needed puzzle piece that would allow astronomers to understand the transition area, and ultimately, the geological history of Mars.

Topographic view of Ismenia Patera. Image credits: ESA.

However, things are not very clear. There are two competing theories: the first one is that it’s a volcano — a supervolcano to be more precise. At some point, the supervolcano would have undergone a massive eruption, which would eject huge quantities of material outwards, collapsing after the magma was thrown out.

The other theory is that it’s actually the site of a meteorite that collided with Mars at some point. So far, the visual data and our limited knowledge of Martian geology are our only clues regarding the nature of this feature. The transitional area shows signs of being the location of an ancient and long-inactive volcanic province. Ismenia Patera does have an irregular shape, low topographic relief, and relatively uplifted rims, which would suggest a volcanic nature. But then again, Mars is also riddled with numerous impact craters, so this remains an open question.

Hopefully, future missions will offer more surface and subsurface data, allowing scientists to finally untangle the planet’s complex and fascinating history.

Supervolcano eruptions might be more common than we thought — but there’s still no need to panic

Supervolcano eruptions would make any other eruption pale in comparison. Image via Wikipedia.

Volcanic eruptions come in many sizes and “flavors”. There are the basic, almost harmless lava flows like in Hawaii, the small rock-throwers, the pyroclastic flows, and then there are the really big ones; on top of all eruptions, in terms of strength, are the so-called supervolcano eruptions, large enough to change life as we know it and potentially return humanity to a pre-civilization state. Needless to say, we’d want to know as much as possible about these eruptions.

Thankfully, they happen quite rarely. A 2004 study estimated that such eruptions (which throw over 1,000 gigatons of material) happen once every 45,000 to once every 714,000 years. There’s no fixed cyclicity and there’s an inherent variability of such estimates, but even at the lower end, that’s not a panic-inducing figure. After all, 45,000 years is much longer than the time that has passed since mankind emerged as a proper civilization. But a new study concluded differently.

Researchers from the University of Bristol’s Schools of Earth Sciences and Mathematics report that, according to their analysis, the average time between such eruptions is only slightly greater than the age of our civilization. Jonathan Rougier, Professor of Statistical Science, says the “best guess value” is once every 17,000 years:

“The previous estimate, made in 2004, was that super-eruptions occurred on average every 45 – 714 thousand years, comfortably longer than our civilization.”

“But in our paper just published, we re-estimate this range as 5.2 – 48 thousand years, with a best guess value of 17 thousand years.”

They reached this conclusion by analyzing a large database. The difference doesn’t necessarily come from a different type of analysis or statistical approach, it comes from the fact that we now we have access to a larger database than we did a decade ago. Basically, we’ve had enough time to do more studies and we now know more about eruptions than we did in 2004.

Based on these recent figures, we’ve been quite lucky to evade supereruptions in our recent history, but it’s also important to note that volcanic activity follows no strict cycle or pattern. Just because eruptions tend to happen with this periodicity doesn’t mean they’ll always stick to it.

“On balance, we have been slightly lucky not to experience any super-eruptions since then,” Rougier added in a statement. “But it is important to appreciate that the absence of super-eruptions in the last 20,000 years does not imply that one is overdue. Nature is not that regular.”

The chances of such an eruption happening in the next 1,000 years is relatively small, and our civilization will change in unforeseeable ways in the next thousand years (just think of how much has changed in the past century). Furthermore, researchers argue, there are other issues far more pressing than a supervolcano eruption.

Journal Reference: ‘The global magnitude-frequency relationship for large explosive volcanic eruptions’ by J. Rougier, S. Sparks, K. Cashman, and S. Brown, in Earth and Planetary Science Letters.

 

Yellowstone volcano might erupt within decades — affecting all of mankind

Beneath the beautiful Yellowstone Park lies an incomprehensibly massive supervolcano. It erupts roughly every 650,000 years, and guess what? It’s been almost 650,000 years since the last eruption.

The Grand Canyon of the Yellowstone downstream from Lower Falls. Credits: Mav.

Geologists differentiate between volcanoes and supervolcanoes — and there’s a good reason for it. Volcano eruptions can be massive and affect millions, but supervolcano eruptions affect the entire planet. There are about 20 known supervolcanoes on Earth, including Lake Toba in Indonesia, Cerro Galán in the Andes, and, of course, Yellowstone.

The Yellowstone volcano is a hotspot, an immobile region fed by magma rising from the underlying mantle. According to analysis of earthquake data in 2013, the magma chamber is 80 km (50 mi) long and 20 km (12 mi) wide. Yellowstone easily has the ability to eject 1,000 cubic kilometers of rock and ash — 250,000 times more than the infamous Mount St. Helens eruption in 1980. If such an eruption occurred, the effects would be devastating. Lava flow won’t spread much — it would be restricted to the vicinity of the park, and vents and fissures would emerge about 10 km around the caldera. Most of the real damage, however, would be caused by the airborne ejecta.

[Also read: Geophysics shows plume of Yellowstone volcano is much larger than previously believed]

The ash would be devastating for much of the United States, and temperatures could drop significantly all around the world. It’s hard to estimate what the net effect would be, but it’s safe to say that it would be massive. Yellowstone has erupted at least three times: 2.1 million years ago, 1.3 million years ago, and 630,000 years ago. We seem to be in the ‘right’ timeframe for another eruption, but thankfully, there seems to be no indication it will happen anytime soon. Even if it were to erupt, we might get some kind of kind of warning. However, a new study puts that last bit into question: the forces driving these destructive events could unfold much quicker than we originally anticipated.

“If something like this happened today, it would be catastrophic,” said Hannah Shamloo, a geologist at Arizona State, speaking to the American Geophysical Union. “We want to understand what triggers these eruptions, so we can set up warning systems. That’s the big-picture goal.”

Depiction of the Yellowstone magma chamber. Image via Wikipedia.

Hannah Shamloo and her colleagues spent weeks at Yellowstone gathering samples. She then analyzed the large crystals in the volcanic rock — these are phenocrysts, which are crystals too large to have formed during the eruptions. These crystals grow slowly outward, carrying within information about their formation conditions (especially about the pressure and temperature). From this, she learned that conditions inside Yellowstone changed just decades before the eruption — the blink of an eye in geological time. Researchers were expecting something like this to happen over the course of thousands of years (which is also not a lot, geologically speaking).

“It’s shocking how little time is required to take a volcanic system from being quiet and sitting there to the edge of an eruption,” said Ms. Shamloo, warning that more research is still necessary before we can draw definite conclusions.

Yellowstone is riddled with geophysical sensors that record temblors and other environmental changes in and around the caldera. Having even an imprecise warning system could prove to be invaluable, but research is demonstrating just how difficult predicting volcanic activity can be. We might be thousands or even hundreds of thousands of years away from an eruption. It might not happen at all. Or, it might happen in a few decades. The only way we’ll have a chance of knowing is through science.

The study has been presented at a recent volcanology conference and has not yet been peer-reviewed.

 

Volcano facts and other pieces of hot science

Volcanoes are some of the most amazing geological features but quite often, they’re misunderstood or not understood at all. Here we’ll get to know them a bit better, starting with the basic facts and the moving onto cool and surprising facts, and of course, continuing with everyone’s favorite (from a distance): eruptions.

Basic Volcano Facts

1. Volcanoes are ruptures in the Earth’s crust. Our planet’s crust is split into 17 major tectonic plates, and almost all volcanoes occur at the edges between these plates.

2. There are three types of volcanoes: stratovolcano (conical volcano consisting of layers of solid lava), cinder cone volcano (steep hill of tephra that accumulates around the vent) and shield volcano (built entirely or almost entirely from fluid lava vents).

3. Volcanoes can be active (with eruptions in the past 10,000 years), dormant (no eruptions in the past 10,000 years, but could wake up) and extinct (unlikely to ever erupt again). However, active volcanoes can become dormant and extinct, and dormant volcanoes can wake up. Before 79 AD, Vesuvius was considered dormant and its eruption was catastrophic. Knowing whether a volcano is truly extinct is hard to determine.

4. We’re still not sure how many volcanoes there are in the world, but geologists identified about 1300 active volcanoes, not counting underwater volcanoes.

5. The biggest volcano on Earth is Hawaii’s Mauna Kea. At 33,500 feet (10,210 meters) it’s even taller than the Everest, but most of it is underwater, so its height relative to sea level is lower. However…

6. The tallest volcano in the solar system is on Mars. Olympus Mons on Mars is a shield volcano with a height of nearly 22 km (16 mi), almost three times higher than Mount Everest. It was able to grow this big because Mars doesn’t have active tectonic plates.

Volcanic eruption on Io. Image credits: NASA/JPL.

7. Earth isn’t the most active place in the solar system – Jupiter’s moon Io is the most volcanic body in the solar system. Astronomers recently witnessed two huge eruptions, possibly largest than any ever recorded on our planet.

8. The two most active volcanoes in the world are Etna in Italy and Hawaii’s Kilauea, depending on how you judge. Etna has been active in the past 3,500 years, but it’s still being used for agriculture because its slopes are so fertile. Kilauea has been in a state of constant eruption since 1993, and more than 90% of its surface is made from young lava.

Image via USGS.

9. Volcanoes can be scary, but supervolcanoes can be downright terrifying. St. Helens, one of the largest eruptions in history spewed up 0.25 cubic kilometers of volcanic material while the last known eruption from the Yellowstone caldera ejected 4000 times more – 1000 cubic kilometers.

Volcano Eruption Facts

10. There are three types of volcanic eruptions: magmatic eruptions (involving gas decompressions that propel the eruption forward), phreatic eruptions (superheating of steam via contact with magma, often with no ejected material) and phreatomagmatic eruptions (compression of gas within magma, the complete opposite of magmatic eruptions).

11. How dangerous are volcano eruptions? In 1815, the volcano Tambora exploded in Indonesia. All vegetation on the island was destroyed and projected into the sea. Uprooted trees mixed with pumice ash, washed into the sea and formed rafts up to 5 km (3.1 mi) across. The eruption sent material into the stratosphere, at an altitude of more than 43 km (27 mi). Over 10,000 people were killed directly by the eruption, but that was only the beginning.

The epic explosion of Mount Tambora in 1815 left a massive crater behind, 3.7 miles wide and 3,600 feet deep. (NASA)

Over 40,000 people were killed by hunger and disease in neighboring islands, and the effects were felt globally. The following year, 1816 was called “the year without a summer”, as snow fell in the summer in Boston and New York. Crops were destroyed, widespread famine was reported in Asia, Europe and the Americas. It’s impossible to estimate the total damage, but up to 100,000 people lost their lives following this eruption. A Massachusetts historian summed up the disaster: “Severe frosts occurred every month; June 7th and 8th snow fell, and it was so cold that crops were cut down, even freezing the roots.” Which leads us to another question:

12. What if a supervolcano erupts? Geologically, it won’t mean much for the planet. At a geological scale, supervolcanoes erupt all the time… but for humans, the effects would be ghastly. The tens or hundreds of thousands of lives lost will pale in comparison to what will happen. The world will be thrown into a nuclear-type winter, where food availability could become a luxury (because volcanic eruptions can block sunlight, lowering global temperatures). Famine and widespread disease will emerge for at least a couple of years, as no country has the food reserves to last that long; it’s extremely difficult to gauge the full impact such an eruption might have. However, you shouldn’t waste much sleep on this – it’s extremely unlikely for such an eruption to take place in the next few thousand of years.

13. The last known supervolcano eruption was the Toba eruption 74,000 years ago, when more than 2,500 cubic kilometers of magma were erupted. The largest eruption in recent human history was the 1815 eruption described above.

Chichester Canal circa 1828 by J. M. W. Turner. Image via Wikipedia.

14. But it’s not all bad. Volcanic eruptions make sunsets more vibrant. The eruptions spew hundreds, thousands or even millions of tons of dust and gaseous sulfur dioxide into the stratosphere. The finer dust particles remain in the atmosphere, sometimes for years, producing vivid sunsets and twilight effects.

In fact, a team of German and Greek researchers are studying paintings of sunsets after historical eruptions to discover clues about our atmosphere, and even study global warming.

Image via Wikipedia.

 

15. Some volcanic eruptions can create massive thunderstorms and we still don’t know exactly why. A study published in Science found that this phenomenon, also called dirty thunderstorms, appear because electrical charges are generated when rock fragments, ash, and ice particles in a volcanic plume collide and produce static charges, just as ice particles collide in regular thunderstorms.

More Volcano Facts

16. You need at least 3.35 kg of lava to boil a liter of water. Quora user Nissim Raj Angdembay calculated that for a lava of an average temperature of 950 °C, you need to use 3.35 kg of lava to boil a liter of water. Of course, this is only a theoretical calculation, and in practice, you’d need a bit more as some of the heat will be lost to the ambient.

17. There is one unique volcano, Ol Doinyo Lengai, that produces black carbonatic lava. It also isn’t as hot as other types of lava and it’s much less viscous – comparable to water.

Black carbonatic lava. Image via SwissEduc

18. The volcanic rock pumice is the only rock that can float in water. Pumice is an extrusive volcanic rock with a very high content of water and gases extruded quickly out of a volcano. The unusual foamy configuration makes it very light.

19. Volcanic energy can be harvested to warm water and even generate electric energy. Geothermal energy generates about 3% of renewable energy-based electricity.

20. The Maleo bird in the Indonesian island of Sulawesi uses volcanic heating to incubate its eggs.

21. When Paricutin in Mexico erupted from 1943-1952 (more on that a bit later), not a single person was killed by lava, rocks or flows, but three people were killed by lightning.

Paricutin. Image via Wikipedia.

 

22. Lava temperature varies between 700 to 1,200 °C (1,292 to 2,192 °F). Geologists do sometimes use a thermometer called a “thermocouple” to take a volcano’s temperature.

23. Lava chemistry greatly influences both the temperature and the type of eruption. Lava with greater silica content (more basic) tends to be hotter, more fluid, and erupt more “gently” – think of the Hawaiian lava flows. Lava with less silica (acidic) tends to have more explosive eruptions. They also form different types of rocks.

24. In 1943, a Mexican farmer named Dionisio Pulido started to notice something strange in his cornfield. It started as a slight depression, and soon started to fissure, eliminating volcanic material. By 1952, the volcano was already 424 meters high and damaged a 233 square km area with the ejection of stone, ash and lava. Three people were killed by lightning as described above. Today, Paricutin the volcano is 2,800 m (9,200 ft) high and is considered dormant.

Magma chamber beneath Yellowstone National Park might be even vaster than thought

Beneath one of the most famous touristic attractions in the world, the Yellowstone National Park, there lies one of the largest and most complex volcanic systems in the world. Yellowstone is a supervolcano of perplexing size, but as Utah seismologists found… it may actually be even bigger than previously thought.

“For the first time, we have imaged the continuous volcanic plumbing system under Yellowstone,” said co-author Hsin-Hua Huang, a post-doctoral researcher in geology and geophysics at the University of Utah. “That includes the upper crustal magma chamber we have seen previously plus a lower crustal magma reservoir that has never been imaged before and that connects the upper chamber to the Yellowstone hotspot plume below.”

A supervolcano is technically defined as any volcano capable of producing a volcanic eruption with an ejecta volume greater than 1,000 km3 (240 cubic miles). Just so you can get an idea, a Yellowstone eruption which took place just over 2 million years ago ejected 2,500 cubic km, while the infamous Mount Helens 1980 eruption only spewed up 0.25 cubic km – 10,000 times less! Needless to say, should Yellowstone erupt, it would be an unprecedented disaster in the history of mankind – a gargantuan event with huge planetary consequences. Naturally, geologists and geophysicists want to understand it as best as possible.

Image via National Geographic.

For this reason, several studies have been undertaken, trying to estimate the extent of the caldera through different methods. Now, scientists from the University of Utah have used a technique called seismic tomography to take a better look at the Yellowstone caldera, and they’ve come up with surprising results: according to their calculations, the caldera is 4.4 times larger than previously thought.

The technique they used is not innovative, although it’s relatively new in the geophysical arsenal of study methods. Seismic tomography is an imaging technique that uses seismic waves generated by earthquakes or controlled explosions to create  computer-generated, three dimensional images of Earth’s interior. The time it takes  for a seismic wave to arrive at a seismic station from an earthquake can be used to calculate the speed along the wave’s ray path. By using arrival times of different seismic waves scientists are able to define slower or faster regions deep in the Earth. There are several material properties which define the wave speed, but under the right circumstances, seismic tomography can reveal deep underground structures – such as the Yellowstone caldera.

“It’s a technique combining local and distant earthquake data better to look at this lower crustal magma reservoir,” Huang says.

A very basic explanation of how seismic tomography works. Image via Northwestern University.

According to their results, the reservoir lies 12 to 28 miles (19 to 45 kilometers) beneath the Yellowstone supervolcano and is more than four times bigger than the magma chamber that is already known to exist. However, this doesn’t really means there’s an increased hazard associated with Yellowstone.

“The actual hazard is the same, but now we have a much better understanding of the complete crustal magma system,” says study co-author Robert B. Smith, a research and emeritus professor of geology and geophysics at the University of Utah.

Jamie Farrell, a co-author of the study published online today in the journal Science added:

“The magma chamber and reservoir are not getting any bigger than they have been, it’s just that we can see them better now using new techniques,” Farrell says.

Series of earthquakes strike Yellowstone

Seismologists working at the University of Utah reported an earthquake occurring at 06:34 AM on March 30, 2014 (MDT). The epicenter of the magnitude 4.8 shock was located 4 miles north-northeast of Norris Geyser Basin in Yellowstone National Park, Wyoming.

A supervolcano

This was not a singular event, but was a part of a series of earthquakes that began in this area on Thursday, March 27 which included over 25 temblors. This was the largest event to take place in Yellowstone since February 22, 1980.

The Yellowstone Caldera is actually a part of a supervolcano, which erupted in massive events 2.1 million, 1.3 million, and 640.000 years ago. Some geologists believe that the supervolcano will erupt again sometime in the next 50.000 years, but based on the style and location of the earthquakes, there’s no reason to expect any other geologic activity aside for continued seismicity – in other words, you shouldn’t panic or worry of a supervolcano eruption – there’s no indication at all that this could happen in the foreseeable future.

If the Yellowstone were in fact moving closer to an eruption, we would get some more severe warnings. Much higher seismic activity, with events probably going up to a magnitude of 6 and even further would be the first warning sign. Then, we’d see changes in hydrothermal features, gas output, ground movement – all at a very high level, which would leave little cause for ambiguity. But what if an eruption would take place?

Yellowstone fallout ash bed.

Yellowstone fallout ash bed.

It’s unclear just how much magma is crystallized in the Yellowstone Caldera, and if it can still erupt with the strength it did 640.000 years ago, but if it did, the results would be devastating. It almost certainly won’t threaten the human race as a species, but for the US, it would be a matter of survival. People from the surrounding states would have to be evacuated almost entirely to be able to survive, and the nation itself would be under extreme pressure. The entire world would probably experience perpetual winter for a few years, as the volcanic ash blocks the sun rays from heating the Earth – it would be unlike anything the human race has ever faced. This is just something to give you a sense of proportion, not something meant  to freak you out. This is a geologic event; it could tens of thousands of years from now, it could never happen again – but it almost certainly not happen in the foreseeable human future.

Anyone who felt the earthquake is encouraged to fill out a survey form on either the Seismograph stations web site: www.quake.utah.edu or the U.S. Geological Survey web site: earthquake.usgs.gov.

Swarm of earthquakes shake Yellowstone National Park

Could the Yellowstone supervolcano be waking up?

faithful

In his 53 years of monitoring seismic activity in and around the Yellowstone Caldera, Bob Smith has never witnessed two simultaneous earthquake swarms; now, the Utah University geophysicist has seen not two, but three such swarms.

“It’s very remarkable,” Smith said. “How does one swarm relate to another? Can one swarm trigger another and vice versa?”

Because such an event is unprecedented, Smith doesn’t want to jump to conclusions, and doesn’t think this is a signal of any potential volcanic eruption.

“A total of 130 earthquakes of magnitude 0.6 to 3.6 have occurred in these three areas, however, most have occurred in the Lower Geyser Basin,” a University of Utah statement said. “Notably much of seismicity in Yellowstone occurs as swarms.”

No significant changes are to be expected, except possibly for geyser activity.

“We know that a significant enough earthquake in the region has potential to alter geyser activity,” the spokesman said. “A strong enough earthquake, like the one that occurred out at Hebgen Lake in 1959, did change the interval of Old Faithful eruptions.”