Stories tagged Earth Structure and Processes

Dec
12
2008

He missed the boat: Actually, Friendventure sailed without him on purpose. We told him to go buy some more gatorade for the trip, and split as soon as he was out of site. You can see it in his eyes.
He missed the boat: Actually, Friendventure sailed without him on purpose. We told him to go buy some more gatorade for the trip, and split as soon as he was out of site. You can see it in his eyes.Courtesy Wikimedia Commons
Ahoy, Buzznauts, the goodship Friendventure has set sail once again. We’ll be traveling through the treacherous waters of the horn (some horn or other—I’m not sure which), where many a young scientist have been sent to their frigid, watery dooms, like so many Leonardo DiCaprios. So set your wills straight, harden your hearts, and focus on the wealth of knowledge at journey’s end!

Let’s see here… what random questions from the science museum are hiding in Lieutenant JGordon’s Random Question Bag? Here we go…

Q) Why aren’t the insides of sweet potatoes white? —Angela

A) Good Q), Angela, but I’m afraid that I might not have a great A) for you. But we’ll see. First of all, sweet potatoes aren’t white like potatoes because they aren’t potatoes. Sweet potatoes are related to “normal” potatoes, but only distantly so—sweet potatoes and potatoes belong to the same order, but different families, genera, and species. That means that sweet potatoes and potatoes are about as closely related as humans are to howler monkeys. And while humans and howler monkeys are probably more or less the same color on the inside, the same doesn’t necessarily apply to plants.

So… sweet potatoes are, in fact, the edible root of a plant very similar to the morning glory flower. They get their color from the compounds in their flesh, compounds that regular potatoes might not have much of. Orange sweet potatoes, for instance, are high in the vitamin beta carotene, the darker they are, the more beta carotene they have. Red, purple, and blue shades of sweet potatoes get their color from anthocycanins, healthy flavonoid molecules that seem to be beneficial in combating cancer, aging, inflammation, diabetes, and bacterial infections. How about that?

Man, that was a great A)! I can’t believe I ever doubted myself.

Q) When did the dinersors die? And why?

A) I appreciate your spelling of “dinosaurs,” friend. Very rich and earthy. Well, sir, when the dinersors died is something we can answer with some certainty—the last of the dinersors died off about 65 million years ago. It was a very sad period for the planet, because dinersors were the most awesome. Let’s put that time (65 million years ago) into perspective: your mom was born about 35 years ago; the cotton gin was invented 215 years ago; the last wooly mammoth croaked about 3700 years ago (don’t argue! We’re talking pygmy mammoths on Wrangel Island); cheese was invented between 10,000 and 5,000 years ago; modern humans evolved about 200,000 years ago; hairy cave people probably figured out how to control fire around 1 million years ago; the Rocky Mountains finished growing about 40 million years ago; and the last dinosaur thought “Wait a second… I haven’t had to wait in line for months!” about 65 million years ago. No dinosaur fossils appear from after that time.

The “why” is trickier, especially if you mean it in a philosophical way. It’s pretty well agreed upon that a six-mile-wide meteorite hit the Earth near where Mexico is today and made life very difficult (impossible) for the dinersors. This doesn’t mean that every dinosaur was literally crushed to death by the meteorite—something that big would certainly have killed a lot of animals immediately, but it would have also thrown so much dust and smoke into the air that temperatures around the planet would drop significantly. It’s like the whole planet was made a little bit shadier for a long time. Even a small change in temperature can have huge effects for some animals—if a lot of plants died from the change in temperature, plant-eating dinosaurs would also die, and then meat-eating dinosaurs would die. Something like that.

There are also some scientists who think that something else entirely, or a combination of things, could have caused the dinersors to all die. One of the main alternative theories is that a series of huge volcanic eruptions in an area of India called the Deccan Traps, finished off the dinosaurs. The eruptions occurred at around the same time as the meteorite impact, and lasted for about 30,000 years. The volcanoes would have had what is scientifically referred to as a “double-whammy” effect on the world of the dinersors: dust from the eruptions would have blocked sunlight, killing off plants, and the massive amounts of volcanic gas released could have contributed to rapid (geologically speaking) global warming on a dramatic scale. Just like with global cooling, an increase in temperature that occurs too quickly can cause extinction for slow-adapting organisms.

Q) Why do turtles have shells?

A) I’m not even going to look this one up. Turtles have shells to protect themselves from the ninja stars of the Foot Clan.

Q) Can any fish breathe air?

A) A nautically themed question! Yes! And, yes, some fish can breathe air.

All fish breath oxygen, but most do it by absorbing gas that is dissolved in water through their gills. The fish that breath air air, if you follow, do it in different ways. Some eels can absorb oxygen right through their skin. Some catfish can gulp air, and absorb it through their digestive tracts. Lungfish and bichirs actually have a pair of lungs, similar to mammals.

Some air-breathing fish will only do so if there is too little oxygen in the water for their gills to work, but some are “obligate air breathers”—they need to breath air occasionally, or they will suffocate. The electric eel is, of course, my favorite obligate air breather. 80% of the oxygen used by electric eels is obtained through breathing air.

And that’s all we have time for right now. Answering random questions is serious business, but then again so is sailing.

Nov
30
2008

Diamonds from Canada: Click on the mafic link for more photos related to hunting for diamonds near the Arctic Circle.
Diamonds from Canada: Click on the mafic link for more photos related to hunting for diamonds near the Arctic Circle.Courtesy mafic

Understand geology

Chuck Fipke, with a degree in geology, was hired out of college by Kennecott Copper to look for gold and copper. About 8 years later Superior Oil hired him to look, not for metals, but diamonds. A Superior geologist named John Gurney, discovered that the presence of chromite, ilmenite, and high-chrome, low-calcium garnet within kimberlite predicted the finding of diamonds. Fipke, combining what he understood of Gurney's work with results coming out of Russian labs and his own skills with field sampling, started looking for diamonds in Canada.

Using what you know, start looking

With Superior's backing, he teamed up with a geologist and pilot named Stewart Blusson, formed Dia Met Minerals, and headed north.

Drill for samples and work "upstream"

De Beers geologists were already looking for diamonds in Canada. Fipke knew that glaciers pushed everything southward so he looked further north. He also noticed that the further North he went the less worn were the edges of the diamonds.

Fipke got a helicopter and flew back and forth over the Arctic Circle, using a magnetometer to track variations in magnetic field that would suggest kimberlite. After thousands of miles and hundreds of hours in the air, he found a promising site near Lac de Gras, a barren world of lakes and rock and muskeg a few hundred miles outside the Arctic Circle.

Keep looking, don't give up

He'd been surveying for eight years. He hadn't found a single diamond. Superior had abandoned the diamond business. Dia Met's stock was trading at pennies a share.

I worked hard, and I mean really hard. I worked seven days a week from 8 am until 3 am. Every day. We drilled and drilled all winter when it was dark and the windchill was 80 below. Everyone thought I was crazy.

Become a billionaire

In 1991, Fipke found a kimberlite pipe (buried under 30 feet of glaciated sediment) with a concentration of 68 carats per 100 tons — the first Canadian diamonds ever found. Shares of Dia Met rocketed to $70.

Chuck Fipke had partnered with mining giant Broken Hill Proprietary Company (now BHP Billiton) to get the diamonds out; BHP opened the Ekati mine at Lac de Gras in 1998. Soon Dia Met's 29 percent share of the mine was worth billions. Fipke would go on to sell his chunk to BHP for $687 million, retaining 10 percent ownership in the mine, worth another $1 billion.

Diamonds from Canada now account for 10 percent of all diamonds by carat sold in the world. The country's four working mines produced 17 million carats in 2007.

Source: How a Rogue Geologist Discovered a Diamond Trove in the Canadian Arctic Wired

Nov
23
2008

Columbia's Nevado del Huila region
Columbia's Nevado del Huila regionCourtesy USGS/R.L. Schuster
The eruption of a volcano in southern Columbia has claimed the lives of at least 10 people and officials fear the death toll will rise.

Nevado del Huila is the highest volcano in Columbia, towering at 17,602 feet. Early last year It came to life after being dormant for more than 500 years.

The volcano is located in a remote area of southeastern Columbia about 150 miles south of Bogota. A number of isolated villages surround the mountain, and thousands were evacuated earlier this week for fear of an impending eruption.

When the eruption finally happened yesterday, it triggered two large landslides along the Paez River. Seven people are still listed as missing and the region remains on high-alert. But the locals have good reason to be nervous. In 1994 several hundred people were killed by landslides from Nevado del Huila induced earthquakes. And nine years before that a nearby volcano named Nevado del Ruiz erupted and killed more than 25,000 people.

LINKS

Story source
Volcano info at the USGS

Oct
28
2008

A gypsum crystal: This crystal, less than a foot tall, can still focus a tremendous amount of chi. Think about what a 36-footer could do!
A gypsum crystal: This crystal, less than a foot tall, can still focus a tremendous amount of chi. Think about what a 36-footer could do!Courtesy Tjflex2
You heard it here first, y’all (unless you heard it somewhere else first): there’s a cave 1000 feet below the Chihuahuan Desert in Mexico, full of crystals dozens of feet long, and thousands of pounds in weight. At least one of the crystals, made of gypsum, is 36 feet long, and weighs over 55 tons. Think of all the powerful spiritual energy there!

The massive crystals grew so large thanks to the 138-degree, mineral-rich water that used to flow through the cave. This mineral soup was perfect for making mega crystals, but lead to the deaths of dozens of New Age crystal prospectors and treasure seeking paladins. (This is an assumption based on my somewhat limited knowledge of crystals and caves.)

The caves were uncovered by miners excavating a new tunnel for a lead and silver mine in the Naica mountain. This happened back in 2000, but I only read about it today, because a story on it will appear (or appears) in the November issue of National Geographic. (Check out those links, by the way—they have pictures, and the caves do look awesome.)

Sep
26
2008

Say you want to walk on the oldest rocks on the surface of the Earth. Well, it turns out that Canada is the place to go. Recently, Science magazine has reported that researchers have found rocks in Quebec that could be as old as 4.28 billion years old. Yes, billion. 4,280,000,000. Now, keep in mind that the Earth is estimated to be around 4.6 billion years old. There are at least three pretty neat points to make here:

1. It is harder than you think to find really old rocks, as most of the crust of the Earth is constantly recycling itself, courtesy of plate tectonics. Fortunately, there is not a great deal of tectonic activity happening in Canada, thus keeping these rocks at the surface.

2. 4.28 billion years old is pretty darn old. Think about it this way; this post is 2,129 characters long. That includes all of the letters and spaces. We will pretend that the very first characters of this post are the youngest, and the ones at the end are the oldest. Humans, which we will understand to be modern Homo sapiens, have only been around for approximately 40,000 years, which would be the very top of the "S" in "Say" that started this post. That is not even one full letter! These rocks have been around for all but the very last sentence of this post. That is a lot of characters/time.

3. They say that these could be the oldest rocks, as old as 4.28 billion years old, but... Dating of really, really old things like this use a technique known as radiometric dating. This type of dating does not give a specific date for the object in question, but rather, a range of dates. So these samples have dates ranging from 3.8 to 4.28 billion years old. The previously known oldest rock samples, also found in Canada, have dates that could be as old as 4.03 billion years old. So... these recently found rocks, if they are actually towards the younger end of their date range, could actually be younger than the potentially 4.03 billion years old rock that was already found.

No matter what, these rocks are still very exciting and can tell us some interesting things about the formation of the Earth's crust!

Sep
11
2008

Thing of the past?: New studies show that the likelihood of a major eruption of Mount Vesuvius, like this computer image of the infamous blast of 79 A.D., are decreasing.
Thing of the past?: New studies show that the likelihood of a major eruption of Mount Vesuvius, like this computer image of the infamous blast of 79 A.D., are decreasing.Courtesy Wikipedia
About a year ago visitors at the Science Museum of Minnesota learned about the disaster that struck Pompeii, Italy, when Mount Vesuvius erupted, wiping out the city and a lot of its residents in the span of just about a day.

Today, about three million people are living within range of a Vesuvius eruption. But the good news from geologists is that they may be under lessened risk for a devastating eruption like the one that hit in 79 A.D.

A new study shows that the volcano’s magma reservoir has been rising up closer to the Earth’s surface over the past 20,000 years. At that higher level, the magma is likely to produce less violent eruptions.

That magma has actually moved quite a bit. Between the huge Pompeii-devastating eruption and another one in the year 472 A.D., the magma pool climbed about 2.5 miles toward Earth’s surface.

But that doesn’t mean people can sleep totally at peace in the volcano’s neighborhood, experts advise. Other factors also play into the severity of a volcano eruption, including tectonic plate shift and the deposit distribution of the magma, factors that weren’t part of this new study.

Jul
26
2008

Gravitational compression

Will Earth ever freeze?: Internal radioactive decay is expected to keep Earth heated for billions of years.
Will Earth ever freeze?: Internal radioactive decay is expected to keep Earth heated for billions of years.Courtesy NASA
In its beginning, the Earth was so hot that it was entirely melted. That heat was generated because of gravitational compression. As gravity pulls materials in outer space towards each other they are compressed. When atoms and molecules are squeezed together they generate heat. Matter at the earth's center is very compressed; in fact, Earth is the densest planet in the Solar system.

Gravitational sorting

Penn State professor of geosciences, Chris Marone, feels that the original heat from that molten earth is only about 5 to 10 percent of the total heat within our planet. Another source of heat is from gravitational sorting.

In a gravitational sorting process called differentiation, the denser, heavier parts were drawn to the center, and the less dense areas were displaced outwards. The friction created by this process generated considerable heat, which, like the original heat, still has not fully dissipated.

Latent heat

Another source of heat is latent heat. When material in the center of the Earth changes from a liquid to a solid, heat is released. The solidified material also expands, which increases the pressure, thereby increasing the temperature. "The inner core is becoming larger by about a centimeter every thousand years," Marone says.

Almost all Earth's heat comes from radioactive decay

Marone says, the vast majority of the heat in Earth's interior—up to 90 percent—is fueled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle. The amount of heat caused by this radiation is almost the same as the total heat measured leaving the Earth.

Source: Penn State University Live

Jul
01
2008

But what a way to go!: Look! I can see my house! Right on the center left, being sucked into an ultra dense, inescapable mass!
But what a way to go!: Look! I can see my house! Right on the center left, being sucked into an ultra dense, inescapable mass!Courtesy NASA
So, what? You wanted to live forever?

Oh, you did? Er…even at the expense of scientific enterprise? Whatever. Deal with it, crybaby, because me and my little Strangelet are going to wring this planet dry.

Do you remember the Large Hadron Collider? No? We posted about it this spring on Science Buzz. It’s a recently completed supercollider in France and Switzerland—the largest supercollider in the world, with a 17-mile circumference. Protons will be blasted through the device so fast that they’ll make the entire circuit 11,000 times per second (which is about the speed of light, I believe). When two streams of protons meet, some of them will collide, and smash apart. At that point two huge detectors will attempt to gather data on just what comes out of the destroyed protons. The hope is that when the machine is switched on in August, we’ll make some fantastic discoveries about the most basic (and yet mysterious) elements of matter.

Oh, and the world might be instantly destroyed. I didn’t mention that last time? Huh. I suppose it just slipped my mind because, you know, who wants to live forever, right?

Some people (read: crybabies) are very concerned that the colliding particles could form a micro-black hole, which could either evaporate instantly, or gobble up the earth. Whoops! There’s some thought that the collider might also produce a spicy little devil we call the “strangelet.”

Stranglets are, it should be said, hypothetical—they’ve never actually been observed. A strangelet is basically a tiny piece of “strange matter,” stuff made up of the same components of regular vanilla matter, but in a unique configuration (equal amounts of up, down, and strange quarks, for those of you in to…quarks, I guess). The fear is that, where a strangelet to come into contact with regular matter on Earth, it could convert that matter into another strangelet, which would convert other matter into strangelets, until the whole of Earth would be turned into a big ball of hot strange matter. Which would just be the pits.

A particular group of people was so worried about the repercussions of turning on the LHC that they actually filed an injunction against its operators. The lawsuit was dismissed, on account of the defenders of humanity just “needing to chill out.”

The plaintiffs claimed that the odds of the LHC creating a global catastrophe are about one in fifty-million—about the same as winning the lottery, but that happens from time to time. Not to me, though.

The scientists behind the LHC, however, argue that the odds are much lower than that even, if not zero. Collisions like those planned for the LHC occur naturally every second, as cosmic rays smack into the earth, and so far everything is all right. Furthermore, should something like a micro-black hole be formed, mega-eggheads like Stephen Hawking predict that it would instantly turn to nothing.

And that’s kind of the thing—some of the world’s biggest smarty-pants are working on this project, and they aren’t concerned. That has to mean something, right? Then again, according to The Incredible Hulk, many scientists aren’t all that concerned about their own certain, imminent death, so long as they get to do some crazy experiments. And I trust comic books implicitly, so who knows.

Jul
01
2008

Good lookin', bad soundin': Radiowaves that get caught up in the Northern Lights are creating some annoying noises that zap out into space.
Good lookin', bad soundin': Radiowaves that get caught up in the Northern Lights are creating some annoying noises that zap out into space.Courtesy NASA
No wonder aliens want to attack the Earth with such regularity in the movies. From out in space, we sound pretty annoying, like that renter in the apartment above you who insists on playing Yoko Ono records at 2:30 in the morning.

You laugh, but new recordings from space show that Earth, our home, makes an array of nasty sounds that ring out across the universe.

Scientists have actually known about this phenomenon since the 1970s. But today we have some audio evidence of this annoying noise. So what’s happening?

There’s a bunch of radiation created high above our planet. Solar winds blow it into Earth’s magnetic field and then things start to get loud. Basically, this radiation gets sucked into the same conditions that cause the Northern Lights. While they look great, they sound horrible – sorta like Brittney Spears.

Earth’s ionosphere keeps the radio waves created in this action from coming down toward us, which is a good thing. That’s because they’re about 10,000 times stronger than any radio signals we have on our planet.

Satellites from the European Space Agency's Cluster mission, however, have now detected strong beams of these annoying radio waves out in space.

Click here to hear a sample of what this space noise sounds like. Personally, I think I’ve experienced this sound, much quieter, after eating a bad burrito.

Jun
15
2008

Killer earthquake strikes Japan

Hundreds of troops armed with shovels and power-saws sifted through the splintered remains of a resort hotel in Japan Sunday in search of survivors after a powerful earthquake struck at around 8.45 a.m. on Saturday. (TurkishPress)

7.2 magnitude quake in Japan

Nine people were killed, 11 are missing, and more than 220 others were injured in the earthquake, the most powerful to strike inland Japan in eight years.

Read more by clicking the link below.
7.2 magnitude earthquake shakes Japan (TimesOnline)