Stories tagged Earth Structure and Processes

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)

Jun
07
2008

Chinese earthquake location
Chinese earthquake locationCourtesy USGS
The Tangjiashan “quake lake”
formed by a landslide during China’s devastating May 12th earthquake is draining slowly thanks to a sluice constructed by engineers there. Fears of the lake bursting from its earthen dam pushed authorities to find a quick and effective way to release the pressure building from the backed-up water. More than a million people living in the area were under threat of being inundated with millions of cubic meters of water.

As work crews start construction of a second drainage channel, engineers are closely watching downstream riverbanks and bridges for any sign of stress from the surging waters.

The 7.9 magnitude earthquake killed over 60,000 people and more than 17,000 are still missing.

SOURCES AND LINKS
AP story
BBC report
Maps and photos of lake region

May
29
2008

Here's mud on your truck: Here's a sample of mudder truck action. These photos are not from the May 3 event near Isanti, Minnesota, which has generated controversy about how much damage a private property owner can do to his own land.
Here's mud on your truck: Here's a sample of mudder truck action. These photos are not from the May 3 event near Isanti, Minnesota, which has generated controversy about how much damage a private property owner can do to his own land.Courtesy katiew
When does a mud hole turn into a wetland?

That’s a question that’s heated up debate in the north metro area as a rural Isanti man now faces wetland damage charges after hosting a mudder truck event on his property earlier this month.

The Minnesota Department of Natural Resources cited the guy under a little-used law for wetland damage. If convicted in court, he could be forced to restore the mud hole/wetland to its former condition, pay a big fine and/or serve jail time.

Chad Hunt, the property owner, contends he can do anything he’d like on his own property and that the area where the trucks were rumbling around on was just a mud hole. About a dozen modified trucks took part in the event on May 3, and also drew a large crowd of spectators.

The DNR took aerial photos of the site after the event (included in the news story link above) that show a large amount of truck ruts and damage.

So what do you think? How far do individual property rights extend when it comes to actions that could have negative environmental consequences? Where does a mud hole end and a wetland begin? What rights does a property owner forfeit when it comes to activities that take place on his property? Share your thoughts here with other Science Buzzers.

May
12
2008

Earthquake in Sichuan, China
Earthquake in Sichuan, ChinaCourtesy U.S. Geological Survey

Toll from China quake estimated at 3,000 to 5,000

A 7.8-magnitude earthquake struck central China, but sent thousands of people rushing out of buildings and into the streets hundreds of miles away in Beijing and Shanghai.
The powerful earthquake trapped nearly 900 students in central China on Monday after their school collapsed and at least 107 people were killed across several provinces, state media reported.Yahoo News

New media allows instant news broadcasting

Blogs and a text message like tool called Twitter allowed the blogosphere to witness first person reports in real time (click examples below)