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for April, 2010.
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond. Visit our website at www.thedeepradioshow.com
Well, I looked over the files today and discovered that the animals were struggling to get out of the file so it’s off on another adventure with the other creatures that share our planet. Well, in at least some of the cases they don’t share it any more and I think you’ll all agree that that’s probably a good thing! So . . . the bad news is that our first subject is snakes. The good news is that these particular snakes aren’t around anymore.
A MEAL FOR TITANOBOA
A 60-million-year-old relative of crocodiles described recently by researchers from the University of Florida and the Smithsonian was probably a food source for Titanoboa, the largest snake ever described. The paleontologists found fossils of the newly described crocodile in the Cerrejon Formation in northern Colombia. The site which is one of the world’s largest open-pit coal mines, also yielded skeletons of the giant, boa constrictor-like Titanoboa, which measured up to 45 feet long. This was the first report of crocodiles from that site.
The new crocodile was named Cerrejonisuchus improcerus grew only 6 to 7 feet long, making it easy prey for Titanoboa. Its scientific name means small crocodile from Cerrejon. (Somehow, I’m having trouble calling a 7 foot long crocodile ’small’!) While Cerrejonisuchus is not directly related to modern crocodiles, it played an important role in the early evolution of South American rainforest ecosystems, said Jonathan Bloch, a Florida Museum vertebrate paleontologist and associate curator.
“Clearly this new fossil would have been part of the food-chain, both as predator and prey,” said Bloch, who co-led the fossil-hunting expeditions to Cerrejon with Smithsonian paleobotanist Carlos Jaramillo. “Giant snakes today are known to eat crocodylians, and it is not much of a reach to say Cerrejonisuchus would have been a frequent meal for Titanoboa. Fossils of the two are often found side-by-side.” Croc as snake food has its parallel in the modern world, since anacondas have been documented eating caimans in the Amazon.
Cerrejonisuchus improcerus is the smallest member of the Dyrosauridae, a family of now-extinct crocodile-like reptiles. Dyrosaurids typically grew to about 18 feet and had long tweezer-like snouts for eating fish. By contrast, the Cerrejon species had a much shorter snout, indicating a more generalized diet that likely included frogs, lizards, small snakes and possibly mammals.
Dyrosaurids split from the branch that eventually produced the modern families of alligators and crocodiles more than 100 million years ago. They survived the major extinction event that killed the dinosaurs but eventually went extinct about 45 million years ago. Most dyrosaurids have been found in Africa, but they occur throughout the world. Prior to this finding, only one other dyrosaurid skull from South America had been described.
On Feb. 1, 2010, Alex Hastings, a graduate student at UF’s Florida Museum of Natural History, measures a jaw fragment from an ancient relative of crocodiles that lived 60 million years ago. The fossil came from the same site in Colombia as fossils of Titanoboa, indicating the ancient croc was a likely food source for the giant snake. (Credit: Photo by Jeff Gage/University of Florida)
A ’small’ crocodile that was food for Titanoboa. And apparently, that’s not all the snakes were eating back in the dinosaur days. We’ll travel from Columbia to India where Indian researchers and paleontologists from the University of Michigan have uncovered a very rare fossil.
AND A DIFFERENT BANQUET
Although our last animal lived after the demise of the dinosaurs, this fossil was found in 67-million-year-old sediments from Gujarat placing its creation about 2 million years before the big one wiped out the dinosaurs.
The researchers were astonished to discover the nearly complete fossil of a snake in the nest of a sauropod dinosaur. The snake was coiled around (and may have crushed) a recently hatched egg and there was at least one newly-hatched baby dinosaur in the nest. Other snake fossils have been found in other egg clutches at the same site indicating that the newly described snake made its living feeding on young dinosaurs.
Now in case you’ve forgotten, sauropods were the largest living land animals. Brachiosaurus, Apatosaurus and Diplodocus are all sauropods. We’re talking 100 feet long here. But, of course, they didn’t plop down from the sky that size, and most sauropods laid eggs. Typically the eggs were round, about 8 inches across and the shell was about ¼ inch thick.
Figuring out the fossil remains was an odyssey. Dhananjay Mohabey, an employee of the Geological Survey of India found the fossils in the early 1980s. Mohabey examined the specimen more fully in 1987. He recognized dinosaur eggshell and limb bones but was unable to fully interpret the specimen. In 2001, Jeff Wilson from the University of Michigan visited Mohabey at his office at the Geological Survey of India and was astonished when he examined the fossil.
“I saw the characteristic vertebral locking mechanism of snakes alongside dinosaur eggshell and larger bones, and I knew it was an extraordinary find—but I also knew we needed to study it further,” Wilson said.
There began a decade-long odyssey that ended with a formal agreement with the Government of India Ministry of Mines in 2004 to allow preparation and study of the fossil at the University of Michigan’s Museum of Paleontology. It also involved weeks of museum study in India, and a field expedition to the original site in Gujarat by a team that included Wilson, Mohabey, snake expert Jason Head of the University of Toronto-Mississaugua, and geologist Shanan Peters of the University of Wisconsin. The field research was funded by the National Geographic Society.
Preparation of the fossil in Michigan revealed the snake was coiled around a crushed dinosaur egg next to a freshly hatched sauropod dinosaur. The researchers think the hatchling had just exited its egg, and that activity attracted the snake. The eggs were apparently laid in loose sand near a small stream and covered by a thin layer of sediment. The arrangement of the bones and delicate structures, such as eggshells and the snake’s skull, point to a very quick burial. The researchers think a pulse of sand that was created by upstream flooding probably buried the eggs, hatchlings and snake.
The snake has been named Sanajeh indicus or “ancient-gaped one from the Indian subcontinent,” because of its lizard-like gape, and it adds critical information to help us understand the early diversification of snakes. Modern large-mouthed snakes are able to eat large prey because they have mobile skulls and wide gapes. Sanajeh has only some of the traits of modern large-mouthed snakes and provides insight into how they evolved.
The snake’s discovery also adds adds to a growing body of evidence that suggests the Indian subcontinent was connected Gondwanaland, the southern landmass that eventually became Antarctica and Australia for longer than we thought. Sanajeh’s closest relatives are from Australia and speak to its strong ties to Gondwanaland.
The hatchling dinosaur was about 18 inches long, but it wouldn’t have given the snake any trouble because it was almost 10 feet long. Mama would have been a problem, of course, but unlike the duck-billed dinosaurs, sauropods apparently didn’t keep an eye on the babies.
This is a life-sized reconstruction of the moment just before preservation. The scales and patterning of Sanajeh’s skin is based on modern relatives of the fossil snake. The hatchling dinosaur is reconstructed from known skeletal materials, but its color is conjectural. The eggs are based directly on the fossils. (Credit: Sculpture by Tyler Keillor and original photography by Ximena Erickson; image modified by Bonnie Miljour)
It took thirty years before the correct interpretation of the fossils in India was made, but that’s a common story in science where even the old discoveries can take on new meaning. And that’s certainly true of our next story where a stunning new dinosaur discovery was made on an expedition to . . . . the Natural History Museum in London!
REDISCOVERING THE BONES
A long forgotten fossil skull in the collections of the Natural History Museum in London has now provided crucial clues to the early stages of the lengthy evolutionary history of the scariest animal that ever lived, Tyrannosaurus rex. Almost a century after its discovery, the specimen, named Proceratosaurus, has now been recognized as the oldest known relative of the tyrannosaurs.
With the help of modern imaging techniques, a team of researchers have been able to show that Proceratosaurus resembled its approximately 100-million-years younger descendant T. rex in a number of ways. The teeth, the jaws, and the cranial cavity structure of the two species have many features in common.
Size wasn’t one of them, though. Proceratosaurus weighed only about 100 pounds. Nevertheless, like the later tyrannosaurs, the animal obviously depended on its powerful mouth and teeth. Later modifications of the jaw muscles and the overall structure of the cranium then gave rise to the perfect hunting weapon wielded by T. rex.
The almost complete skull of Proceratosaurs was found in the West of England about 100 years ago. It was initially misclassified, but was later recognized as representing an otherwise unknown genus, which was named Proceratosaurus.
Little is known about the origins and later evolution of tyrannosaurs and researchers hope Proceratosaurus will cast some much needed light on the process. Since some of the skull was still embedded in rock it had to be carefully freed by the team that discovered it languishing in a drawer. They also did a CAT scan of the skull which let them look at the inside of the skull without damaging it.
The investigations uncovered a wide range of features in the cranial cavity, teeth and jaws that Proceratosaurus shares with T. rex, despite the fact that the Proceratosaurus skull is about 100 million years older and much smaller. The Proceratosaurus cranium was about five times less massive than that of its mighty relative, and the intact animal appears to have weighed only about 100 pounds. Mature specimens of T. rex, in contrast, weigh up to eight tons.
The reclassification of Proceratosaurus also confirms that the tyrannosaurs developed over a very long stretch of time, and gave rise to a great diversity of forms. The researchers are hopeful that we won’t have to wait another hundred years to find more members of the family.
Fossil skull of Proceratosaurus, recently rediscovered in the collections of London’s Natural History Museum. It is the oldest-known relative of T. rex and it lived 165 million years ago. (Credit: Image courtesy of Natural History Museum of London)
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
It has been a long time since I visited the medicine file and there are some stories in there that will brighten your day so I decided to pull them out. I was personally interested in the first story because if I eat breakfast, it’s always a Golden Delicious apple. Perhaps that’s why I tend to be a little healthier than my contemporaries.
AN APPLE A DAY . . . .
Why does an apple a day keep the doctor away? Some researchers from Denmark have published a new study that shows that eating apples really is good for you.
Microbiologists from the National Food Institute at the University of Denmark fed rats a diet that was rich in whole apples, apple juice, and pomace, what’s left over after you press the water from any fruit. They also had (as all good scientists do) a control group that got the standard rat fare.
Then, they analyzed the types of bacteria found in their intestines to measure the content of ‘friendly’ gut bacteria, the kind that digest your food for you and mainly by their sheer numbers prevent nasty disease causing bacteria from causing you problems.
Some gut bacteria are also thought to influence your risk for cancer but the problem is that many bacteria types can’t be cultured in a petri dish. So the Denmark team used genetics instead of petri dishes to examine the microbiology of the rat intestines. There’s a certain kind of RNA (16S rRNA) found only in bacteria and its chemical makeup is unique to each species of bacteria. By examining the kinds of RNA in the rat intestines, the researchers could figure out what kinds of bacteria were present.
The scientists found that rats that ate a diet high in pectin (a dietary fiber found in apples and other fruit) had increased amounts of ‘good’ bacteria; the kind that digest your food for you and protect you against cancer.
Co-researcher Andrea Wilcks said. "It seems that when apples are eaten regularly and over a prolonged period of time, these bacteria help produce short-chain fatty acids that provide ideal pH conditions for ensuring a beneficial balance of microorganisms. They also produce a chemical called butyrate, which is an important fuel for the cells of the intestinal wall."
Of course, further research is needed to determine whether the digestive system of humans responds to apples in the same way as rats, but these findings certainly suggest that an apple a day is not a bad way to go!
And now, we turn from apples to everyone’s favorite food. Of course, as a scientist, I can’t really make that generalization. Everyone has favorite foods and foods they dislike. I don’t like watermelon and in my entire life, I’ve met only three other people who didn’t like watermelon either. But you know, I don’t think I’ve ever met anybody who didn’t like . . . chocolate! And now for the absolute, all-time best news.
CHOCOLATE MAY BE GOOD FOR YOU!
According to a recent analysis published by Canadian researchers, eating chocolate may lower your risk of having a stroke. A different but aligned study found that eating chocolate may lower your risk of death after you suffer a stroke. The analysis involved reviewing three studies on chocolate and stroke.
The first study found that 44,489 people who ate one serving of chocolate per week were 22 percent less likely to have a stroke than people who ate no chocolate. The second study found that 1,169 people who ate 50 grams of chocolate once a week were 46 percent less likely to die following a stroke than people who did not eat chocolate.
The researchers found only one additional relevant study in their search of all the available research. That study found no link between eating chocolate and risk of stroke or death.
Chocolate is rich in antioxidants called flavonoids, which may have a protective effect against stroke, but more research is needed to determine whether chocolate truly lowers stroke risk, or whether healthier people are simply more likely to eat chocolate than others.
A new analysis finds that eating chocolate may lower your risk of having a stroke. (Credit: iStockphoto/Emre Ogan)
Since my typical dessert for both lunch and dinner is two pieces of dark chocolate, I have been doing myself a big favor. Man, I really LIKE these articles!!!!
And now onto another study that features our ever-present lab mice and . . . . CHOCOLATE!
ADDICTED TO CHOCOLATE?
Did you ever get a buzz from eating chocolate? Since I try to watch my weight, I try to limit my chocolate intake to those two pieces for dessert, but a recent study in Italy has shown that chocolate-craving mice will to tolerate electric shocks to get their chocolate fix.
Rossella Ventura worked with a team of researchers from the Santa Lucia Foundation, Rome, Italy, to study the links between stress and compulsive food-seeking. She said, “We used a new model of compulsive behavior to test whether a previous stressful experience of hunger might override a conditioned response to avoid a certain kind of food – in this case, chocolate”.
Ventura and her colleagues first trained well-fed mice and starved mice to seek chocolate in one chamber rather than going into an empty chamber. Then, they added a mild electric shock to the chamber containing the chocolate.
Unsurprisingly, the well-fed animals avoided the sweet treat. However, mice that had previously been starved, before being allowed to eat their way back up their normal weight, resisted this conditioning and continued to seek out chocolate despite the painful consequences.
This is an index of compulsive behavior and the researchers claim that this matches compulsive food seeking in the face of negative consequences in humans.
I’m not so sure I believe that. I think it simply means “I’m starving. Bring on the chocolate even if it hurts!”
So . . . this last study raises the evil specter of chocolate addiction (Bwah-ha-ha-ha). And believe it or not, the next study may show us not only true addiction, but it may point to the evolutionary processes that gave us some addicting substances to begin with.
THE CAUSE OF ADDICTION?
Israeli scientists have made a remarkable discovery. Bees prefer nectar with small amounts of nicotine and caffeine over nectar that has none. And this has some really interesting implications for the plant production of these addictive substances.
Flower nectar is mostly sugar, which provides energy for the potential pollinators of the flower. But the floral nectar of some plant species also includes small quantities of substances known to be toxic, like caffeine and nicotine. In the present study the researchers were trying to find out whether these substances are produced to "entice" the bees or if they’re just byproducts of a flower doing its business.
Nicotine is found naturally in floral nectar at a concentration of up to 2.5 milligrams per liter, mainly and unsurprisingly in the tobacco plant (Nicotiana glauca). Caffeine is found at much high concentration levels of 11-17.5 milligrams per liter, mostly in in citrus flowers. In the nectar of grapefruit flowers, however, caffeine is present in much higher concentrations, reaching 94.2 milligrams per liter.
In order to examine whether bees prefer nectar containing caffeine and nicotine, the researchers offered artificial nectar with varying sugar levels and varying levels of caffeine and nicotine, and used nectar made from sugar alone as a control. The caffeine and nicotine concentrations ranged from the natural levels in floral nectar to much higher concentrations than found in nature.
The results showed that bees clearly preferred the nectar containing nicotine and caffeine over the plain sugar water. The preferred nicotine concentration was 1 milligram per liter, similar to that found in nature. Given a choice of higher levels of nicotine versus sugar water, the bees preferred the latter.
According to the researchers, it’s hard to determine for sure whether the addictive substances in the nectar are there because of an evolutionary process in order to make pollination more efficient (i.e. attract more pollinators).
It can be assumed, however, based on the results of the study, that plants that have survived natural selection are those that developed "correct" levels of these addictive substances, enabling them to attract and not repel bees, thereby giving them a significant advantage over other plants. The researchers emphasized that this study has proved a preference, not addiction, and they are currently examining whether the bees do indeed become addicted to nicotine and caffeine.
Hmmmm. All flowering plants must be pollinated and there are lots of methods by which this is accomplished. But insects are the most common pollinators and if they can be lured by substances like caffeine and nicotine, why not by theobromine (the ‘active’ ingredient in chocolate) and by even morphine and codeine. I think some studies need to be done on the nectar contents of Theobroma cacao and Papaver somniferum (the opium poppy). The results might be very interesting.
And what an interesting concept. That the blame for an incredibly wide range of human misery and degradation could possibly be laid directly at the feet of thrill-seeking . . . bees.
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Well, as I looked over the files today, I realized that it has been a long time since I did a column on that branch of science that pays my salary: astronomy. As I tell the kids who visit the Planetarium, I love my field because it changes every single day. Things I teach them today may change tomorrow. It’s already happened this semester. I taught them that although we used to think that Mars was a dead world, the discovery of methane in the atmosphere says that either there is volcanic activity on Mars or there’s primitive life.
I just told them a few weeks ago that although we now know that something is happening on Mars, as far as we know, Venus is a dead world. That changed last week when they compared radar images of Venus and discovered the landscape had changed. There are apparently active volcanoes on Venus.
The field of astronomy is definitely like a famous quote by one of its most important scientists. As Sir Isaac Newton said “To myself, I am only a child playing on the beach, while vast oceans of truth lie undiscovered before me.” We are only beginning to tap into that vast ocean. So join me as I take you on only a few of the more recent forays.
We just had our lecture on the formation of new stars. The current theories state that stars form from big spinning clouds of dust and gas. Gravity draws these clouds together and a huge spinning mass ultimately forms at the center of the cloud. The spinning slings material away at the protostar’s equator which forms a very dense cloud around it.
This dense cloud prevents material from escaping the star as it heats up from the interior pressure. So most newborn stars have jets of gas and dust that exit at their poles. This incredible fire hose streams create some astounding structures and have attracted lots of research.
The problem is that as you can see in the photo, there are breaks in the outrushing plasma. It isn’t a steady stream of material as you would expect, and astronomers have had real problems explaining how these jets achieve their varied shapes. Now, laboratory research gives us some clues about how magnetism shapes these stellar jets.
The prevailing theory (and the one I taught my students) says that the jets are basically fire hoses that shoot out matter in a steady stream, and the stream breaks up as it collides with gas and dust in space. But Adam Frank, professor of astrophysics at the University of Rochester, and co-author of the new paper says that that apparently isn’t what happens at all.
He said, "These experiments are part of an unusual international collaboration of plasma physicists, astronomers and computational scientists. It’s a whole new way of doing astrophysics. The experiments strongly suggest that the jets are fired out more like bullets or buckshot. They don’t break into pieces—they are formed in pieces."
Frank says the experiment, conducted by Professor Sergey Lebedev’s team in the Department of Physics at Imperial College London, may be the best astrophysical experiment that’s ever been done. Replicating the physics of a star in a laboratory is exceptionally difficult, he says, but the Imperial experiment matches the known physics of stellar jets surprisingly well. "Lebedev’s group at Imperial has absolutely pioneered the use of these experiments for studying astrophysical phenomena. The collaboration between Imperial and Rochester has been going on for almost 5 years and now it is bearing some extraordinary fruit."
Lebedev sent a high-powered pulse of energy into an aluminum disk. In less than a few billions of a second, the aluminum began to evaporate, creating a cloud of plasma very similar to the plasma cloud surrounding a young star. Where the energy flowed into the center of the disk, the aluminum eroded completely, creating a hole through which a magnetic field from beneath the disk could penetrate.
The field initially pushes aside the plasma, forming a bubble within it. As the field penetrates further and the bubble grows, however, the magnetic fields begin to warp and twist, creating a knot in the jet. Almost immediately, a new magnetic bubble forms inside the base of the first as the first is propelled away, and the process repeats.
The researchers compare the magnetic fields’ affect on the jet to a rubber band tightly wrapped around a tube of toothpaste—the field holds the jet together, but it also pinches the jet into bulges as it does.
"We can see these beautiful jets in space, but we have no way to see what the magnetic fields look like," says Frank. "I can’t go out and stick probes in a star, but here we can get some idea, and it looks like the field is a weird, tangled mess."
Frank says other aspects of the experiment, such as the way in which the jets radiatively cool the plasma in the same way jets radiatively cool their parent stars, make the series of experiments an important tool for studying stellar jets. With this new model, he says, astronomers don’t have to assume that the knotted jets they see in nature are caused by some unknown phenomenon but by good old basic physics.
Using these tools has allowed us to wade a little way into that vast ocean, and caused me to revise my astronomy notes yet again!
Still image from a movie of stellar jet simulation. (Credit: Image courtesy of University of Rochester)
Now we’ll journey a little closer to home for a look at some of the other tools that are allowing us to explore the great cosmic ocean. And if you’re talking here in the solar system, the tools are, without question, robots.
We’ve been sending robots into space for fifty years now, and they have become our primary tools for space exploration since we can’t seem to get the money together and/or generate the interest to do it ourselves.
From the Russian lunar rovers that explored the Moon long before Neil Armstrong first stepped on its surface; the Voyagers, the pioneer explorers of the outer planets; our many Martian orbiters and landers and Galileo and Cassini , the chroniclers of Jupiter and Saturn; robots have revealed the new, the unexpected and the wonderful to our astounded eyes. Our next story is about Saturn, but its basis isn’t from Cassini, our robot in orbit around Saturn. This news come from the robot that typically explores deep space and has answered so many old questions and posed so many new ones, I’ve lost count. It is, of course, the Hubble Space Telescope.
NEW RINGS ON SATURN
Saturn takes thirty years to go round the Sun one time and since it’s tilted as it spins just like the Earth, we can see both poles only when it’s either spring or autumn on Saturn and its tilt is parallel to the Sun. This is the point where the rings disappear for us, and it happened last year.
Saturn has a magnetic field just like Earth and like Earth it interacts with the solar wind. The solar wind is charged particles emitted by the Sun and as I tell my students, it’s perfectly true that Earth and all the other planets are inside the Sun because the ‘edge’ of the Sun doesn’t occur until far beyond Neptune where the Sun’s particles stop and true interstellar space begins.
When the charged particles interact with Earth’s magnetice field they’re funnelled in toward the poles. As they get deeper into Earth’s air, they hit atoms and molecules and give up their energy, causing the molecules to glow. This eerie glow in far northern and southern skies is called the aurora and for those of us lucky enough to have seen it, it’s utterly beautiful.
Saturn also has aurora and when Saturn was at its equinox point last year, Hubble was able to take a picture of aurorae occurring simultaneously at Saturn’s north and south poles. At first, the light shows appeared symmetric. But further analysis shows that there are some differences between the northern and southern aurorae, which reveal important information about Saturn’s magnetic field. The northern auroral oval is slightly smaller and more intense than the southern one, implying that Saturn’s magnetic field is not equally distributed across the planet; it is slightly uneven and stronger in the north than the south. As a result, the electrically charged particles in the north are accelerated to higher energies as they are fired toward the atmosphere than those in the south. This confirms a previous result obtained by the space robot Cassini, in orbit around the ringed planet since 2004.
Double aurorae on Saturn (Credit: NASA, ESA and Jonathan Nichols (University of Leicester))
And now, let’s return to the changes on Mars that just might indicate that there’s bacterial life on Mars that’s producing that methane and let’s go get an update from Cassini about the brightest little snowball in the solar system.
I’ve done several articles on Enceladus, the little 300-mile wide snowball that orbits Saturn. Enceladus is incredibly important because it wobbles as it goes around Saturn and that tells us that not all the water inside it is frozen. We knew that 20 years ago. But it was confirmed by the Cassini robot when it took pictures of liquid spewing from that the scientists called ‘tiger strips’ at the moon’s south pole.
Since Cassini has fulfilled its primary mission (and then some!) they flew the robot through the spewing liquid last year. And a team from the Mullard Space Science Laboratory working on the Cassini mission has found negatively charged water ions in the plumes. The spacecraft’s plasma spectrometer, used to gather this data, also found other species of negatively charged ions including hydrocarbons.
MSSL’s Professor Andrew Coates said: "While it’s no surprise that there is water there, these short-lived ions are extra evidence for sub-surface water and where there’s water, carbon and energy, some of the major ingredients for life are present.”
Enceladus thus joins Earth, Titan and comets where negatively charged ions are known to exist in the solar system. Negative oxygen ions were discovered in Earth’s ionosphere at the dawn of the space age. At Earth’s surface, negative water ions are present where liquid water is in motion, such as waterfalls or crashing ocean waves.
The plasma spectrometer measures the density, flow velocity and temperature of ions and electrons that enter the instrument. It wasn’t designed to fly through a fountain but it is doing just fine, thank you, in analyzing the material erupting from the inside of Enceladus.
Early in its mission, Cassini discovered the plumes fairly early and since then, scientists have found that this erupting water and ice dominates Saturn’s magnetic environment and create Saturn’s huge E-ring.
The new findings add to astronomers’ growing knowledge of the detailed chemistry of Enceladus’ plume and give us new insight on locations where life-sustaining environments might exist.
Professor Keith Mason, Chief Executive of the Science and Technology Facilities Council (STFC), which funds the UK involvement in Cassini, said: "This measurement of water ions in the ice plume of Enceladus is incredibly exciting and provides us with further hope of finding water and maybe even life on this distant icy moon."
Cassini captured this stunning mosaic of Enceladus as the spacecraft sped away from the geologically active moon of Saturn. (Credit: NASA)
I have a feeling that the story is only beginning for Enceladus and that we will probably be very surprised one day at what the Cassini robot finds expelled from the interior of Enceladus. We could be rewriting much more than my astronomy lecture on Saturn!
Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Having done animals and medicine for a while, it’s time to turn to Mother Earth and see what the latest news is about her periodic eruptions. Our first story concerns a volcano we’ve discussed several times here in this column. It’s not your typical volcano, but there’s no denying that it’s been destructive. But what makes Lusi really unique is the possibility that we humans really have become a geologic force.
LAYING THE BLAME
Researchers have discovered new data that provides the strongest evidence so far that Lusi, the world’s biggest mud volcano, which killed 13 people in 2006 and displaced thirty thousand people in East Java, Indonesia, was not caused by an earthquake.
There have been conflicting claims about Lusi’s origins. Lapindo Brantas, a large Indonesian drilling firm was drilling a gas exploration well near where Luisi erupted and many people think that drilling was the trigger for the volcano. But Lapindo Brantas has claimed that an earthquake that occurred 280 kilometers (174 miles) away was what caused the volcano to erupt. They backed up their claims in an article accepted for publication in the journal Marine and Petroleum Geology, by lead author Nurrochmat Sawolo, senior drilling adviser for Lapindo Brantas, and colleagues.
In response, a group of scientists from the United Kingdom, United States, Australia and Indonesia led by Richard Davies, director of the Durham Energy Institute, have written a discussion paper in which they refute the main arguments made by Nurrochmat Sawolo and document new data that provides the strongest evidence to date of a link between the well and the volcano. That paper has been accepted for publication in the same journal.
"The disaster was caused by pulling the drill string and drill bit out of the hole while the hole was unstable," Davies said. "This triggered a very large ‘kick’ in the well, where there is a large influx of water and gas from surrounding rock formations that could not be controlled.
"We found that one of the on-site daily drilling reports states that Lapindo Brantas pumped heavy drilling mud into the well to try to stop the mud volcano. This was partially successful and the eruption of the mud volcano slowed down. The fact that the eruption slowed provides the first conclusive evidence that the bore hole was connected to the volcano at the time of eruption."
Lusi first erupted on 29 May 2006, near Indonesia’s second largest city of Surabaya. The mud from the volcano now covers nearly three square miles and is 65 feet thick. It has destroyed four villages and 25 factories. Thirteen people died as a result of a rupture in a natural gas pipeline underneath one of the holding dams. The Lusi crater has been oozing enough mud to fill 50 Olympic size swimming pools every day. All efforts to stem the mud flow have failed, including the construction of dams, levees, drainage channels, and even plugging the crater with concrete balls. Lusi may continue to erupt for decades, scientists believe.
Arguments over what caused the volcano to erupt have stalled the establishment of liability for the disaster and delayed compensation to thousands of people affected by the mud. The Yogyakarta earthquake that occurred at the time of the volcano was cited by some as a possible cause of the eruption, but the research team rejected this explanation.
View of the Lusi mud volcano crater and the dikes and dams constructed to contain the still-oozing mud. (Credit: Courtesy of Channel 9 Australia)
Richard Davies may in fact be right that Lapindo Brantas caused the eruption with their drilling. But the real fun is going to be to get them to admit it. Just like the volcano isn’t done spewing its mud over everyone, I doubt that the mud-slinging of blame is over either!
Now we’ll turn our attention to another volcano in our area of the world. But there’s no question that people had nothing to do with this one. It’s been around for longer than there have been people and it not only has deep roots in time, it has them in the earth too. Read on!
Ever since the 60’s when geologists began to realize that Alfred Wegner was right with his wacko theories about cruising continents, the island of Hawaii has presented a bit of a problem. We could readily explain volcanoes at the boundaries where plates split apart or collide, the island of Hawaii was bang in the middle of a plate but there was no denying that it was in fact, a giant volcano.
A classic explanation, proposed nearly 40 years ago, has been that magma is supplied to these volcanoes from upwellings of hot rock, called mantle "plumes," that originate deep in the Earth’s mantle. It’s a nice theory, but substantiation proved a little hard to provide. Now, a sophisticated array of seismometers deployed on the sea floor around Hawaii has provided the first high-resolution seismic images of a mantle plume with its origins at least 1,000 miles below the Earth’s surface.
This unprecedented glimpse of the roots of the Hawaiian "hot spot" is the product of an ambitious project known as PLUME, for Plume-Lithosphere Undersea Melt Experiment, which collected and analyzed two years of data from sea floor and land-based seismometers.
The PLUME images show a seismic anomaly beneath the island of Hawaii, the chain’s largest and most volcanically active island. Critics of the plume model have argued that the magma in hot spot volcanoes comes from relatively shallow depths in the upper mantle not deep plumes, but the anomaly observed by the PLUME researchers goes down at least 1,000 miles . Rock within the anomaly is also calculated to be significantly hotter than its surroundings, as predicted by the plume model.
Erik Hauri, also of Carnegie’s Department of Terrestrial Magnetism, led the geochemical component of the research. "We had suspected from geochemistry that the center of the plume would be beneath the main island, and that turns out to be about where the hot spot is centered," he says. "We also predicted that its width would be comparable to the size of island of Hawaii and that also turned out to be true. But those predictions were merely theoretical. Now, for the first time, we can really see the plume conduit."
Location of seismic velocity anomaly at a depth of 746 miles beneath Hawaiian Islands (outlines). Orange color indicates low S-wave velocities, implying higher rock temperatures. Open boxes show locations of sea-floor seismometers. (Credit: Image courtesy of Science)
Lucky for the people of Indonesia that the plume under Lusi isn’t that big (or that hot!). And now a look using the same techniques at a supervolcano; one that most people who visit it aren’t even aware of.
THE BIGGEST ONE?
Yellowstone National Park is one of the premier vacation destinations in the United States. All those boiling hot calderas and geysers were a fascinating find in the middle of uncharted wilderness 200 years ago and they continue to fascinate today. But if you think that their existence is a mystery to the layman, it was also a mystery to geologists. What was all that activity doing in the middle of a continent?
At the same time geologists were wondering about Hawaii, they began to realize with dawning interest (and some horror) that the two questions had the same answer. Not only was there a gigantic mantle plume under Hawaii, there was also one under Wyoming and Yellowstone National Park isn’t just an interesting destination for tourists, it’s the mouth of one of the world’s largest volcanoes.
Using the same techniques as the researchers in Hawaii (although this group didn’t have to contend with the problem of how to get your seismometers on the ocean floor!) a team from the University of Utah has published a picture of the plumbing that feeds the Yellowstone supervolcano which shows a plume of molten rock that stars at least 400 miles down and rises at an angle from the northwest. This contradicts claims that there is no deep plume under Yellowstone, only shallow hot rock moving like slowly boiling soup.
A related study used gravity measurements to indicate the banana-shaped magma chamber of hot and molten rock a few miles beneath Yellowstone is 20 percent larger than previously believed, so a future cataclysmic eruption could be even larger than thought.
Some 17 million years ago, the Yellowstone hotspot was located beneath the Oregon-Idaho-Nevada border region, feeding a plume of hot and molten rock that produced "caldera" eruptions — the biggest kind of volcanic eruption on Earth.
As North America slid southwest over the hotspot, the plume generated more than 140 huge eruptions that produced a chain of giant craters — calderas — extending from the Oregon-Idaho-Nevada border northeast to the current site of Yellowstone National Park, where huge caldera eruptions happened 2.05 million, 1.3 million and 642,000 years ago.
These eruptions were 2,500, 280 and 1,000 times bigger, respectively, than the 1980 eruption of Mount St. Helens. The eruptions covered as much as half the continental United States with inches to feet of volcanic ash. The Yellowstone caldera, 40 miles by 25 miles, is the remnant of that last giant eruption.
The Yellowstone caldera, like other calderas on Earth, huffs upward and puffs downward repeatedly over the ages, usually without erupting. Since 2004, the caldera floor has risen 3 inches per year, suggesting recharge of the magma body beneath it.
Scientists have debated for years whether Yellowstone’s volcanism is fed by a plume rising from deep in the Earth or by shallow churning in the upper mantle caused by movements of the overlying crust. The current study has produced the most detailed image of the Yellowstone plume yet published.
But a preliminary study by other researchers suggests Yellowstone’s plume goes deeper than 410 miles, ballooning below that depth into a wider zone of hot rock that extends at least 620 miles deep.
Seismic imaging was used by University of Utah scientists to construct this 3-D picture of the Yellowstone hotspot plume of hot and molten rock that feeds the shallower magma chamber (not shown) beneath Yellowstone National Park, outlined in green at the surface, or top of the illustration. (Credit: University of Utah)
Researchers say that if the Yellowstone supervolcano were to erupt, it would devastate the entire United States. Just more proof that Mother Nature may just be the biggest mother of them all!
Jim is, above all, a passionate eco-humanitarian who has developed his own science talk-radio show to inform The DEEP’s listeners about such newsy topics as global warming, shark-finning and reef protection as well as to explore earth’s many underwater and space mysteries.
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