- Sublime Sand: Desert Dunes Seen From Space
- Collar Tech Tracks Wolf’s North Pole Treks
- Famous San Francisco Sea Lions Abandon Their Pier 39 Post
Posted: 28 Dec 2009 05:00 PM PST
<< previous image | next image >>
Deserts are known for being desolate and lifeless, but they are also quite striking and beautiful, especially when seen from above. Different types of sand, topography, wind and climate combine to form a tremendous variety of landscapes. Shifting dunes are carved into an endless number of constantly changing shapes.
The images in this gallery, taken by orbiting astronauts and satellites, show some of the most beautiful, most haunting, biggest, rarest and most stunning desert vistas on Earth.
Algeria's Sand Sea
The Issaouane Erg covers almost 15,000 square miles in eastern Algeria. This sea of sand in the central Sahara desert has three different scales of dunes. Mega-dunes, also known as draas or whalebacks, form over hundreds of thousands of years and can be several hundred miles long. Mesoscale dunes form on top of the mega-dunes, and move on decade time scales. Smaller dunes form on and around the larger dunes. They are sculpted into different shapes by the wind, and are constantly shifting.
In the image above, captured by astronauts on the International Space Station in 2005, mesoscale dunes have been shaped into star dunes that look a bit like starfish and crescent dunes. In the image below, taken by astronauts on the ISS in 2006, the large, rolling shapes are mega-dunes. The smallest dunes show up as wrinkles alongside larger dunes.
Click on any of the gallery images for high-resolution versions.
Posted: 28 Dec 2009 03:50 PM PST
During the 24-hour darkness of an arctic winter, a wolf pack's tough life continues. Battling temperatures that reach 70 degrees below zero, a pack travels hundreds of miles across the landscape. A collar affixed to a wolf named Brutus beams back their coordinates to U.S. Geological Survey researchers.
It would be impossible for humans to track the wolves in the brutal conditions, but the new satellite collar, which can communicate with GPS and Arcos satellites, is passing its first field test with flying colors.
"This year, we made a huge technological jump from notebook and pens to satellite collars because we wanted to find out what these arctic wolves do in winter," USGS biologist David Mech said in a press release. "How far must they travel to obtain enough food to make it to the Arctic spring, which doesn't happen until the next June?"
The data being returned by the collar is unprecedented. No one has ever collared a wolf within 1,000 miles of the Brutus' pack, Mech told Wired.com.
As it turns out, the wolves are covering a lot of ground, as can be seen in the map above. Now, the fjords visible in the summer image above have frozen and can be crossed on foot. In one trip, the wolf and his pack traveled 80 miles from Ellesmere Island to Axel Heiberg Island and back in just 84 hours. Just through November 30, Brutus has traveled 1,683 miles.
And that's just counting the point-to-point distance between locations they receive from the collar's transmitter. They only get the wolf's coordinates every 12 hours, so it's highly probable that the wolf has taken far more circuitous, longer paths through the snow.
"With the locations coming at 12-hour intervals we can't precisely say what Brutus was doing, but no doubt he was hunting and likely resting at times too," wrote Northwest Territories biologist Dean Cluff, who is working on the project with Mech, on the project's blog.
The wolves travel to find prey like muskoxen and Arctic hares, so the researchers expected them to be on the move, but they didn't know exactly how far they'd go or where. During the summer months, the pups can't travel with the pack, so the older wolves' movements are limited. They figured that as the babies grew up, they would be able to make longer treks and the pack's range would grow.
Now they know they were right, thanks to the wolf pack locations that periodically show up in Mech's inbox. The information satisfies his lifelong desire to solve the mystery of how these wolves survive when he can't be in the Arctic charting their movements.
"I've studied them for 25 years, 25 summers, but I've never known what they've done after I leave," Mech said in a podcast [mp3].
Posted: 28 Dec 2009 12:31 PM PST
The blubbery sea lions at Pier 39, one of San Francisco's smelliest and most famous tourist attractions, are gone. During the last week of November, they left the wooden docks on which they've spent the last 20 years and no one knows if they'll be coming back.
"We have no idea where they moved on to or why," said Shelbi Stoudt, who manages a team that helps stranded animals in the San Francisco Bay from the Marine Mammal Center in Sausalito, California.
The sea lions' disappearance is as strange as their initial colonization of the pier about 20 years ago, in late 1989. They just started showing up one day and as their numbers increased, their traditional hang out, Seal Rocks, became less populated. There are all sorts of theories about why the pier became a favorite haul-out spot for the sea lions, butno one knows for sure why the animals' behavior changed.
Stoudt averred that the officials at the Marine Mammal Center weren't worried about the animals' disappearance from their standard location. The sea lions are migratory animals, after all, and it's natural for them to move around.
So, even though no one has found them, "there really isn't a reason to be looking for them," Stoudt said.
The disappearance is unusual, though. The animals' numbers usually peak in late fall and many stick around during the winter months before heading south for the summer. According to the Marine Mammal Center's FAQ on the animals, "from late summer to late spring, 150 to 300 sea lions haul out here," though their numbers can run much higher.
This year saw a massive influx of sea lions. In fact, a Marine Mammal Center survey conducted in the fall found 1,585 mammals hauled out on the spot, an all-time high. Some of them invaded a neighboring area, the Hyde Street Pier, where they may have been scared away by an itinerant fisherman's dog.
Their disappearance drew the attention of San Franciscans like local blogger Gary Soup, who posted the photo above of the deserted docks on Twitter.The animals had become a major tourist and education locus on the otherwise highly commercial strip known as Fisherman's Wharf. The Marine Mammal Center sends docents to the area to answer questions about the creatures.
On the other hand, fishermen and others who work the waters of the Port of San Francisco have far less friendly relations with the animals. One recently told a local radio station, "They're cute when they're in here lying on the docks by Pier 39, but they're not too cute out in the ocean when they're stealing your livelihood."
It doesn't appear that local weather conditions could have influenced the animals. The weather in San Francisco has been normal, according to National Weather Service meteorologist Rick Canaepa. "It's pretty typical winter conditions," Canaepa said.
This is an El Niño year, but the local impacts of that warming of the Pacific have been moderate. "I don't know if that would be enough to make them change their minds and leave the area," he said.
The Mammal Center's Stoudt said they hadn't detected signs of something unusual going on with the fauna of the Bay, either.
While it's appealing to think that the animals may have just returned to their previous home at Seal Rocks, locals contacted by Wired.com didn't think there had been much of a change in the sea lion population there.
"Nothing unusual has happened," said Jennifer Valencia, who takes reservations at the Cliff House, which overlooks the Rocks.
So, for now, no one knows where they've gone or whether they'll ever head back to their perch amid the clam chowder shops and street performers.
|You are subscribed to email updates from Johnus Morphopalus's Facebook notes |
To stop receiving these emails, you may unsubscribe now.
|Email delivery powered by Google|
|Google Inc., 20 West Kinzie, Chicago IL USA 60610|