Blood Falls, named for its ruddy colour, is not, in fact, a gush of blood from some unseen wound.
The colour was initially chalked up to red algae, but a new study in the Journal of Glaciology has uncovered its true origin using radar to scan the layers of ice from which the river pours.
Located in Antarctica’s McMurdo Dry Valleys, the falls pour forth from Taylor Glacier, and the liquid bubbles up from fissures in the glacier’s surface.
The flow was previously a mystery, as the mean temperature is -17 degrees Celsius and little glacial melting can be seen at the surface.
Imaging from underneath the glacier helped solve the mystery, revealing a complex network of subglacial rivers and a subglacial lake—all filled with brine high in iron, giving the falls its reddish tint.
According to the study, the makeup of the brine explains the fact that it flows instead of freezes.“The brine remains liquid within the subglacial and englacial environments through latent heat of freezing coupled with elevated salt content,” the study explains.
A hadrosaur Skeleton, Field Museum (Credit: Lisa Andres)
by Paul Rodgers.
Dinosaurs would be walking the Earth today if it weren’t for a “colossal” piece of bad luck.
Had the asteroid that brought their reign to an end struck at “a more convenient time” they could well have survived the cataclysm, according to new research.
And that in turn would mean no humans.
“If dinosaurs didn’t go extinct, then mammals would have never had their opportunity to blossom.
So if it wasn’t for that asteroid, then humans probably wouldn’t be here. It’s as simple as that,” said Dr Stephen Brusatte, a palaeontologist at Edinburgh University’s school of geosciences.
“Not only did a giant asteroid strike, but it happened at the worst possible time, when their ecosystems were vulnerable,” said Dr Brusatte, a co-discoverer of the Pinnochio rex tyrannosaur (Qianzhousaurus sinensis) announced in May.
“It was a perfect storm of events, when dinosaurs were at their most vulnerable.”
A triceratops at the American Museum of Natural History (Credit: Wikipedia)
The arrival of the Chicxulub bolide (comet or giant meteorite) 66 million years ago, in what is now Mexico’s Yucatan Peninsula, left a crater 20km deep and 180km in diameter and caused a global catastrophe including firestorms, tsunamis, and earthquakes.
The 10km wide rock released enough dust, ash, and aerosols into the air to create a global “impact winter” that lasted for a decade.
The Cretaceous-Paleogene extinction event (formerly known as the Cretaceous-Tertiary) is thought to have killed three quarters of the earth’s species.
At particular risk were large creatures – the dinosaurs – that depended on equally large food intake.
Only those dinosaurs that could fly survived, eventually evolving into today’s birds.
In 21st century America, train travel isn’t seen as very futuristic. But in the years after World War II, trains were right up there with airplanes as the coolest in luxurious transportation of tomorrow.
And in 1947 Americans got a peek at what was promised to be their train-bound future.
It was called the Train of Tomorrow, first conceived by General Motors in 1944 simply as a scale model promotional tool.
But after the war, people working on the project were excited enough that GM contracted with Pullman to actually build it.
The train went out on a 28-month tour of the U.S. and Canada and became a symbol of postwar promises for the future of getting around.
Nearly 6 million people walked through the train as it toured, though a much smaller group got to actually travel on it.
The website Streamliner Memories has uploaded a fantastic color brochure of the train from 1947. Many of the images below come from that brochure.
The GM Train of Tomorrow had a brief existence touring North America and most of the cars that comprised it sat dormant after 1950, until they were finally sold off for scrap in the mid 1960s.
But thanks to the magic of internet™ we can get a taste of what it must’ve been like to ride the train of the future.
Is your feline friend purring because he’s happy, or could it be something else? (Photo: Travis Modisette/flickr)
It’s easy to assume that cats purr because they’re happy. After all, when your kitty contentedly curls up in your lap for some well-deserved scratches and rubs, she’s obviously one happy feline.
However, cats also purr when they’re frightened or feel threatened, such as during a visit to the vet. Veterinarian Kelly Morgan equates this reaction with smiling.
“People will smile when they’re nervous, when they want something, and when they’re happy, so perhaps the purr can also be an appeasing gesture,” Morgan told WebMD.
A cat’s purr begins in its brain. A repetitive neural oscillator sends messages to the laryngeal muscles, causing them to twitch at a rate of 25 to 150 vibrations per second.
This causes the vocal cords to separate when the cat inhales and exhales, producing a purr. But not all cats can purr. Domestic cats, some wild cats and their relatives — civets, genets and mongooses — purr, and even hyenas, raccoons and guinea pigs can purr.
However, cats that purr can’t roar, and cats that roar can’t purr because the structures surrounding roaring cats’ larynxes aren’t stiff enough to allow purring. Roaring cats evolved this way for good reason.
These cats move around a lot to catch prey, so they developed their roar to protect their prides and their territory.
Purring cats, on the other hand, are smaller and more likely to be loners that don’t have to compete with each other for prey. They use scent to mark territory and don’t need a far-reaching way to communicate.
However, your cat may also purr to communicate with you. According to researchers at the University of Sussex, domestic cats can hide a plaintive cry within their purrs that irritates their humans while appealing to their nurturing instincts.
The team examined the sound spectrum of 10 cats’ purrs and found an unusual peak in the 220- to 520-hertz frequency range embedded in the lower frequencies of the usual purr. Babies’ cries have a similar frequency range at 300 to 600 hertz.
Karen McComb, who headed the study, said cats may be exploiting “innate tendencies in humans to respond to cry-like sounds in the context of nurturing offspring.
”Why would your feline do this? “Cats apparently learn to do this to get people to feed them sooner,” said veterinarian Benjamin L. Hart.Cats’ purrs are more than simply a way to communicate though.
Scientists like Elizabeth von Muggenthaler, a bioacoustics researcher, believe that cats also purr to heal themselves.
Anatomically, the wolverine is a stocky and muscular animal. With short legs, broad and rounded head, small eyes and short rounded ears, it resembles a bear more than other mustelids.
Though its legs are short, its large, five-toed paws and plantigrade posture facilitate movement through deep snow.
The adult wolverine is about the size of a medium dog, with a length usually ranging from 65–107 cm, a tail of 17–26 cm, and a weight of 9–25 kg, though exceptionally large males can weigh up to 32 kg.
The males are as much as 30% larger than the females and can be twice the females’ weight. Shoulder height is reported from 30 to 45 cm.
It is the largest of terrestrial mustelids; only the marine-dwelling sea otter and giant otter of the Amazon basin are larger.
Wolverines have thick, dark, oily fur which is highly hydrophobic, making it resistant to frost. This has led to its traditional popularity among hunters and trappers as a lining in jackets and parkas in Arctic conditions.
A light-silvery facial mask is distinct in some individuals, and a pale buff stripe runs laterally from the shoulders along the side and crossing the rump just above a 25–35 cm. bushy tail.
Some individuals display prominent white hair patches on their throats or chests.
Like many other mustelids, it has potent anal scent glands used for marking territory and sexual signaling. The pungent odor has given rise to the nicknames “skunk bear” and “nasty cat.”
Wolverines, like other mustelids, possess a special upper molar in the back of the mouth that is rotated 90 degrees, towards the inside of the mouth.
This special characteristic allows wolverines to tear off meat from prey or carrion that has been frozen solid.
The wolverine is a powerful and versatile predator and scavenger.
Prey mainly consists of small to medium-sized mammals, but the wolverine has been recorded killing prey such as adult deer that are many times larger than itself.
Prey species include porcupines, squirrels, beavers, marmots, rabbits, voles, mice, shrews, lemmings, caribou, roe deer, white-tailed deer, mule deer, sheep, moose, and elk.
Smaller predators are occasionally preyed on, including martens, mink, foxes, Eurasian lynx, weasels, and coyote and wolf pups.
Wolverines often pursue live prey that are relatively easy to obtain, including animals caught in traps, newborn mammals, and deer (including adult moose and elk) when they are weakened by winter or immobilized by heavy snow.
Standing 16 feet tall at the shoulder and weighing 20 tons, Paraceratherium was one of the largest mammals to ever walk the Earth.
That may seem pretty puny by dinosaurian standards, but, at the American Museum of Natural History and other institutions that house reconstructions of the 34-23 million year old animal, the hornless rhino towers over every other beast. Only a few extinct elephants have come close to its impressive stature.
As is often the case with the large and fossiliferous, though, it’s too easy to get wrapped up in the nature of the beast and forget the history that assembled the creature before us. University of Manchester historian Chris Manias recounts the tale in a new paper.
In the case of Paraceratherium, the great rhino only emerged after years of toil, study, and, most importantly, collaboration between researchers who were independently drawn to the remains of the same giant.
Before the rhino could get a name or start casting shade over museum halls, the titan had to be discovered.
The British paleontologist Clive Forster-Cooper had the honor.
Curious about fossils regularly found by England’s Indian Geological Survey among the Bugti Hills of Baluchistan, Foster-Cooper organized a 1910-1911 expedition to see the fossils for himself.
The work was more difficult than Forster-Cooper had hoped. In the age of imperial paleontology, he took the traditional route of hiring unskilled local workers who he frequently groused about to his esteemed colleagues elsewhere.
Not only were the local Nawab people suspicious of the paleontologist’s true motives – who would be travel all the way out there for old bones? – but Forster-Cooper complained that he had to fire three workers for “idleness and insubordination” and did not trust the remaining three with anything more than rudimentary digging around.