Discovery News: Earth Impacts News

Green Alleys

There's something a little unnerving about highway travel in Georgia and other eastern US states. It's not the heavier traffic or the way folks drive. In the former, I've seen just as nasty in Los Angeles. As for the latter, they only differ in the minor respect of rules: Georgia drivers generally seem to follow them, while back home in Albuquerque the drivers tend to put more stock in a vigorous "Hail Mary" and creative vehicular improvisation. No, the thing that unerves me about these Eastern highways are the trees lining the way. Miles and miles of towering, leafy arborage just dripping with kudzo or their own foliage. It's a great view for botanists, I supose, but hard on geologically-inclined eyes. You can't see a darned bit of countryside beyond those trees. There's no way to get a feel for the landscape. Nothing to see but long verdant alleys. Even my 10-month-old son Walker at first looked out from his car seat on the endless vegetable parade with what appeared to be some puzzlement. Maybe he was wondering "Hey, who switched the color of my world?" But that was yesterday, when we first arrived in Georgia. Today he's totally adjusted to it. It's all normal to him. To my much older arid land eyes, on the other hand, it'll always look a little freaky.

Myanmar: Before & After

Here are two satellite images from NASA's Earth Observatory showing the flooding in Myanmar from Cyclone Nargis. Click on them to enlarge. Here's some of NASA's explanation:

"Flood water can be difficult to see in photo-like satellite images, particularly when the water is muddy. This pair of images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite use a combination of visible and infrared light to make floodwaters obvious. Water is blue or nearly black, vegetation is bright green, bare ground is tan, and clouds are white or light blue."

Nowcasting meets Stratocasting

I was just skimming through the latest issue of the Bulletin of the American Meteorological Society and I was struck my this word: Nowcasting. I've seen it before but hadn't really focused on it. Nowcasting, as I understand it, is weather forecasting that is very near term -- just hours and minutes before the weather hits you. This is a realm of forecasting where human judgment, not computer models, still rules. That's because the scale of weather very close to the here and now is extremely specific and detailed. It's the difference between "A chance of showers" and  "Honey, where'd you stow the lifevests?" It's just not economical to make computers look that closely, so weatherpersons have to fill this in on their own using what they know about local conditions.

Here's the fun part: Anyone who watches the sky and monitors the local Doppler radar online is a sort of nowcaster. So even I'm a nowcaster (which is really cool, because it's the closest I'll ever get to being a forecaster).

Take care, however, not to confuse a nowcaster with a thencaster. That's a person who reminisces about weather. Like those fogies who say things like "This is nothing like the drought breaker monsoon of '89, when electrified toads dropped from green thunderheads...." For what it's worth, I consider myself a nowcaster and a thencaster.

One more word of advice: If you too are a now and/or thencaster, avoid specializing too much. You may quickly find yourself wandering into foreign lands of language and culture. A nowcaster who is particularly good at watching stratus clouds might be tempted to call himself a stratocaster, which is a kind of electric guitar. This could lead to some confusion.

Stratus cloud photo by Jeffrey Lew, copyright University Corporation for Atmospheric Research

Dust in the Neighborhood

Earth is not alone in its orbit around the Sun. As this picture shows, there is also a lot of dust in our neighborhood that can be seen if you are in a very dark place. This image of "gegenschein" was just released by the European Southern Observatory's Very Large Telescope facility in Paranal, Chile. Far from cities and at an elevation of 8,600 feet (2,635 meters) above sea level, it's possible to see not only the wedge of dust that fills interplanetary space (called zodiacal light), but to even catch the extra glimmering highlight of the dust which is just opposite the Sun as it reflects sunlight back at Earth. I've seen Zodiacal light, but hadn't even heard of gegenshein before this.

One More Earth Circle

This one is one of my favorites Earth circles. I've even spotted it out the window of aircraft. Can you guess what & where it is? (The answer will appear soon in Comments section).
By the way, there is a reason I've been obsessing lately about circular features on Earth. I was recently discussing them with a researcher Jay Melosh of the University of Arizona. He mentioned that he gets a lot of crazy emails from folks who search satellite imagery now available online. They are looking for circles to call their own. Craters, mostly, to explain this, that or the other pet theory or to name after themselves or their beloved departed parakeet.

Most, like the Richat Structure shown in a posting last week, are not necessarily craters at all. It turns out, instead, that  Earth has a variety of ways of drawing circles on herself. Some ways are mundane, like erosion. Others are more violent, like caldera eruptions. All of them seem to tickle the fancy of geometrically inclined brains like those of humans.

Suspicious Katrina Pictures

I'm a natural born skeptic. That's why when a friend forwarded me these images, I did not instantly believe the accompanying breathless text, also forwarded:

"Whoever took these pictures did an awesome job. Whoever said, 'awesome and terrifying' is telling the truth. Wow, take a look at this ... Worth passing on!!! The dance with Katrina, part of her beauty as she left destruction on her exit. They are remarkably dramatic.
These pictures were made by a man in Magee, MS where the eye of the storm passed thru - what an experience.  Magee is 150 miles North of Waveland, Mississippi where the Hurricane made landfall."

These are, indeed, awesome images, but whenever I get poorly sourced materials, I get suspicious. Anyone have any more info on these? Are they even from Mississippi? They look like they could be from anywhere in Tornado Alley. (The answer is now available in comments section -- LarryO', 5/6)

Reno's Swarming Quakes

One minute all is peaceful and serene and the next quakes are swarming like angry bees. That is, after all, why they call them earthquake "swarms." Just such a swarm is now underway west of Reno, Nevada. I hear there have been scores of tremors felt in the city, including a M4.2 trembler on April 24 followed by a M4.7 shaker on April 25. The USGS has put out the word that because of the shallow 1 to 3-mile depth of the quake ruptures there is little chance that they are being caused by roiling hot magma preparing to unleash God's wrath on Las Vegas' sinful northern sister. Nope. Just a little subterranean stress relief going on is all. Please calmly proceed back to your favorite blackjack table.

For a little local color on this, my father wrote me to tell me that my two older siblings are right now visiting Reno and my sister Molly abandoned her 8th floor hotel room as a result of the nerve wracking rattling. Mind you, my sis is no sissy. Like the rest of us, she was born and raised within view of the San Andreas Fault (when the smog allowed us to see that far). No one except maybe an earthquake engineer really wants to be in a large building during an earthquake. Give me a flexible "stick-built" home any day over all that steel, concrete and glass.

Another Ring...

Okay. Here's another Earthly ring. This one is in Africa. Any guesses? (See comments section for the answer)

What's this Ring?

The moment I saw this satellite image I thought "particle accelerator." But I was wrong. Can you guess what this man made ring is? The answer is on the comments section.

(Hint: It's in Italy and does, indeed, involve acceleration.)

Tale of Two Quakes

The U.S. Geological Survey has wasted no time warning folks that Friday's Illinois earthquake was a "wake-up call." In a press release and podcast they reminded folks that no place is quake-free. They also pointed out something a tad more subtle that is often lost in the news coverage: That quakes in the Midwest are felt far more widely than in places like California.

These two shake maps  demonstrate this. The on left shows how the shaking was felt last Friday in Illinois. On the Right is a comparable quake in California. I've deliberately shrunk the California map to make it appear at a similar scale to the Illinois map (click on them to view at full original size -- and very different scales). Notice how far the shaking is felt in Illinois compared to the white zones of no shaking felt in California.

What did Midwesterners do to deserve this more jittery ground? They simply settled on geological Jello. It turns out that all those sands, silts and other river, lake and glacier sediments that span such huge areas of the Midwest are very easily jiggled by earthquakes and they transmit that energy far and wide. Now throw into that Jello a few mountain ranges and major faults to deflect, reflect and otherwise mess with the seismic energy -- as is the case in California -- and the shaking doesn't reach nearly as far. Something to think about before labeling any place "earthquake country."