by David Braun
Enter Undulatus Asperatus
Pretor-Pinney jokingly calls it the “Jacques Cousteau cloud,” after its resemblance to a roiling ocean surface seen from below. But the cloud fan has proposed a “formal,” Latin name: Undulatus asperatus—roughly, “a very turbulent, violent, chaotic form of undulation,” explained Pretor-Pinney, author of the new Cloud Collector’s Handbook.
TRUTH:
A CLOUD CAN WEIGH MORE THAN A MILLION POUNDS.
Margaret LeMone, a cloud expert with the National Center for Atmospheric Research in Boulder, Colorado, said that she has taken photos of asperatus clouds intermittently throughout the past 30 years. It’s likely that the cloud will turn out to be a new variety, LeMone said. “Having a group of people enthusiastic about clouds can only help the field of meteorology,” she added.
Asked how such a striking cloud type could go unrecognized, Pretor-Pinney cites its rarity—and the proliferation and portability of digital cameras. “Technology has allowed us to have this new perspective on the sky.”
Wild Cards
This apparently new class of cloud is still a mystery. But experts suspect asperatus clouds’ choppy undersides may be due to strong winds disturbing previously stable layers of warm and cold air. Asperatus clouds may spur the first new classification in the World Meteorological Organization’s International Cloud Atlas since the 1950s, Pretor-Pinney said.
“Even if you live in the middle of the city, the sky is the last wilderness you can look out on.”
Gavin Pretor-Pinney
cloud enthusiast and author of Cloud Collector’s Handbook
Since the last addition to the atlas, the emergence of satellite imagery has pushed meteorologists to take a much broader view on weather and focus less on small-scale cloud formations. But “the tide is turning back again,” in part because the humble cloud is seen as a “wild card” in climate-change prediction, Pretor-Pinney said.
LeMone agreed that clouds are a “big unknown” in climate change, mostly because climate-change models do not provide a high-enough resolution to determine what clouds’ impacts will be on a changing world.
A Bad Rap
Gavin Pretor-Pinney, who is proposing that asperatus clouds be officially recognized, said that clouds get a “bad rap.” “People complain about … having a cloud hanging over them, compared to someone having a sunny outlook on life,” said Pretor-Pinney. “To me, clouds are one of the most beautiful parts of nature.”
CAVE OF WONDERS
Solved! The Case of the Giant Crystals
A team of geologists have solved the mystery behind the formation of giant crystals in a Mexican cave known as the “Sistine Chapel of crystals.”
Buried a thousand feet (300 meters) below Naica Mountain in the Chihuahuan Desert, the spectacular wonder was discovered by two miners excavating a new tunnel for the Industrias Peñoles company in 2000. They found a cave filled with some of the largest natural crystals ever found: translucent gypsum beams measuring up to 36 feet (11 meters) long and weighing up to 55 tons.
TRUTH:
INSIDE THE CAVE OF CRYSTALS, THE AVERAGE TEMPERATURE IS 122 DEGREES FAHRENHEIT, WITH ALMOST 100 PERCENT HUMIDITY.
“It’s a natural marvel,” said Juan Manuel García-Ruiz, of the University of Granada in Spain.
It took seven years for geologist García-Ruiz and a team of researchers to unlock the mystery of just how the minerals in Mexico’s Cueva de los Cristales (Cave of Crystals) achieved their monumental forms.
Massive beams of selenite dwarf an explorer in the Cave of Crystals. (Photo Credit 9.8)
Underwater Wonder
To learn how the crystals grew to such gigantic sizes, García-Ruiz studied tiny pockets of fluid trapped inside. The crystals, he said, thrived because they were submerged in mineral-rich water with a very narrow, stable temperature range—around 136 degrees Fahrenheit (58 degrees Celsius). At this temperature the mineral anhydrite, which was abundant in the water, dissolved into gypsum, a soft mineral that can take the form of the crystals in the Naica cave.
Caves of Swords and Crystals
The mining complex in Naica contains some of the world’s largest deposits of silver, zinc, and lead. In 1910, miners discovered another spectacular cavern beneath Naica.
Its walls studded with crystal “daggers,” the Cave of Swords is closer to the surface, at a depth of nearly 400 feet (120 meters). While there are more crystals in the upper cave, they are far smaller, typically about a yard (a meter) long.
The Cave of Crystals is a horseshoe-shaped cavity in limestone rock about 30 feet (10 meters) wide and 90 feet (30 meters) long. Its floor is covered in crystalline, perfectly faceted blocks. The huge crystal beams jut out from both the blocks and the floor. “There is no other place on the planet where the mineral world reveals itself in such beauty,” García-Ruiz said.
Looters, Beware
The Cave of Crystals’ stifling temperatures and the fact that it takes 20 minutes to drive to its entrance through a twisting mine shaft hasn’t prevented looters from trying to get a piece of the treasure. One of the crystals was found with a deep scar where someone tried, but failed, to cut through it. Subsequently, the cave has been supplied with a heavy steel door.
Cooling Off Creates Crystals
Volcanic activity that began about 26 million years ago created Naica Mountain and filled it with high-temperature anhydrite, which is the anhydrous—lacking water—form of gypsum. Anhydrite is stable above 136 degrees Fahrenheit (58 degrees Celsius). Below that temperature gypsum is the stable form.
When magma underneath the mountain cooled and the temperature dropped below 58 degrees Celsius, the anhydrite began to dissolve. The anhydrite slowly enriched the waters with sulfate and calcium molecules, which for millions of years have been deposited in the caves in the form of huge selenite gypsum crystals. “There is no limit to the size a crystal can reach,” García-Ruiz said.
But, he said, for the Cave of Crystals to have grown such gigantic crystals, it must have been kept just below the anhydrite-gypsum transition temperature for many hundreds of thousands of years. In the upper cave, by contrast, this transition temperature may have fallen much more rapidly, leading to the formation of smaller crystals.
TRUTH:
THE WORLD’S LARGEST KNOWN CRYSTAL IS 37.4 FEET LONG. THAT’S EIGHT TIMES TALLER THAN THE AVERAGE TEN-YEAR-OLD.
To Reflood or Not to Reflood
While the chance of this set of conditions occurring in other places in the world is remote, García-Ruiz expects that there are other caves and caverns at Naica containing similarly large crystals. “The caves containing larger crystals will be located in deeper levels with temperatures closer to, but no higher than, 58 degrees Celsius,” he said.
He has recommended to the mining company that the caves should be preserved.
The only reason humans can get into the caves today, however, is because the mining company’s pumping operations keep them clear of water. If the pumping is stopped, the caves will again be submerged and the crystals will start growing again, García-Ruiz said.
So what happens if—or when—the mine is closed?
“That’s an interesting question,” García-Ruiz said. “Should we continue to pump water to keep the cave available so future generations may admire the crystals? Or should we stop pumping and return the scenario to the natural origin, allowing the crystals to regrow?”
THE BLOBS!
Giant, Mucuslike Sea Blobs
On the Rise, Pose Danger
As sea temperatures have risen in recent decades, enormous sheets of a mucuslike material have begun forming more often, oozing into new regions, and lasting longer, a new Mediterranean Sea study says. And the blobs may be more than just unpleasant.
Beware of the blob—this time, it’s for real. Up to 124 miles (200 kilometers) long, the mucilages appear naturally, usually near Mediterranean coasts in the summer. The season’s warm weather makes seawater more stable, which facili
tates the bonding of the organic matter that makes up the blobs. Now, due to warmer temperatures, the mucilages are forming in winter too—and lasting for months.
“The suit was impossible to wash totally, because it was covered by a layer of greenish slime.”
Serena Ford Umani
co-author of mucilage study, on the state of her wet suit after diving into the blob
More than a Nuisance
Until now, the light-brown “mucus” was seen as mostly a nuisance, clogging fishing nets and covering swimmers with a sticky gel—newspapers from the 1800s show beachgoers holding their noses, according to study leader Roberto Danovaro, director of the Marine Science Department at the Polytechnic University of Marche in Italy.
But a study found that Mediterranean mucilages harbor bacteria and viruses, including potentially deadly E. coli, Danovaro said. Those pathogens threaten human swimmers as well as fish and other sea creatures, according to the report, published in the journal PloS One.
Building the Perfect Blob
A mucilage begins as “marine snow”: clusters of mostly microscopic dead and living organic matter, including some life-forms visible to the naked eye—small crustaceans such as shrimp and copepods, for example. Over time, the snow picks up other tiny hitchhikers, looking for a meal or safety in numbers, and may grow into a mucilage.
The blobs were first identified in 1729 in the Mediterranean, where they’re most often seen. The seas relative stillness and shallowness make the water column more stable, providing ideal conditions for mucilage formation. For this study, Danovaro and colleagues studied historical reports of mucilage in the Mediterranean from 1950 to 2008. Outbreaks, they discovered, were more likely when sea-surface temperatures were warmer than average.
TRUTH:
MUCILAGES WERE FIRST IDENTIFIED IN THE MEDITERRANEAN IN 1729.
Smelly Green Slime
In 1991, Italian marine biologist Serena Fonda Umani swam alongside a mucilage—the mass is too dense to swim inside—in the Adriatic Sea, an arm of the Mediterranean. She remembers diving about 50 feet (15 meters) down when she got the sensation of a ghost floating over her—“sort of an alien experience.”
Umani, a co-author of the new study with Danovaro and Antonio Pusceddu, of the Polytechnic University of Marche, has also dived into marine snow—the mucilage’s precursor. She described it as being like swimming through a sugar solution. Out of the water, the dried “sugar” stiffened her hair and stuck to her wet suit. “The suit was impossible to wash totally, because it was covered by a layer of greenish slime,” said Umani, of Italy’s University of Trieste. “It was a nightmare.”
Few people would purposely swim into a mucilage, said Farooq Azam, a marine microbiologist at the University of California’s Scripps Institution of Oceanography. “If you were not familiar with this—and especially if you were familiar—you wouldn’t want to go near it,” said Azam, who was not involved in the new study. A giant odiferous blob drifting offshore is “certainly not the seascape that one goes to the beach [for],” Azam added.
Health Hazard
Umani and colleagues sampled coastal waters and mucilage from the Adriatic in 2007. The study team discovered that the blobs are hot spots for viruses and bacteria, including the deadly E. coli. Study leader Danovaro said, “Now we see that … the release of pathogens from the mucilage can be potentially problematic” for human health.
Beach Bacteria
In 2005, the Clean Beaches Council, a Washington, D.C.-based advocacy group, issued a report that the sand at many U.S. beaches contains bacteria that indicate potentially unhealthy levels of fecal material. The indicator bacteria, which include a benign form of E. coli, pose little health risk to people, but still serve as warning signs that harmful fecal microorganisms may be present as well. The report is meant to raise awareness for beachgoers to “leave no trace” when visiting the beach and to wash up after playing in the sand.
Fish and other marine animals that have no choice but to swim with mucilages are most vulnerable to their disease-carrying bacteria, the study says. The noxious masses can also trap animals, coating their gills and suffocating them, Danovaro said. And the biggest blobs can sink to the bottom, acting like a huge blanket that smothers life on the seafloor.
Mucilages aren’t a concern for just the Mediterranean, Danovaro added. Recent studies tentatively suggest that mucus may be spreading throughout oceans from the North Sea to Australia, perhaps because of rising temperatures, he said.
“It’s a good example [of what will happen if] we don’t do something to stop climate warming,” Danovaro said. “There are consequences [if] we continue to deny the scientific evidence.”
Beyond warm temperatures, it’s still not exactly clear what drives the blobs’ formation, Scripps’ Azam pointed out. For instance, no one knows why the dead marine matter in the blobs doesn’t decompose. “It’s important we do find out” what’s driving the rise of the blobs, Azam said, “for the sake of the rest of the worlds’ oceans.”
STATUES OVERBOARD!
“Bodies” Fill Underwater Sculpture Park
Off the shores of Cancún, Mexico, stand hundreds of statues, a new underwater sculpture garden that doubles as an artificial reef.
More than 400 of the permanent sculptures have been installed in 2010 in the National Marine Park of Cancún, Isla Mujeres and Punta Nizuc as part of a major artwork called “The Silent Evolution.” The installation is the first endeavor of a new underwater museum called MUSA, or Museo Subacuático de Arte.
TRUTH:
THE SCULPTURES ARE MADE FROM CEMENT, SAND, MICROSILICA, FIBERGLASS, AND LIVE CORAL.
Created by Mexico-based British sculptor Jason deCaires Taylor, the Caribbean installation is intended to eventually cover more than 4,520 square feet (420 square meters), which would make it “one of the largest and most ambitious underwater attractions in the world,” according to a museum statement. Along with creator Taylor, a team of artists, builders, marine biologists, engineers, and scuba divers are working together to complete it.
In doing so, Taylor hopes the reefs, which are already stressed by marine pollution, warming waters, and overfishing, can catch a break from the approximately 750,000 tourists who visit local reefs each year. “That puts a lot of pressure on the existing reefs,” Taylor told National Geographic News. “So part of this project is to actually discharge those people away from the natural reefs and bring them to an area of artificial reefs.”
School of Rock
The sculptures are made of a special kind of marine cement that attracts the growth of corals, according to creator Taylor. That in turn encourages fish and other marine life to colonize the reef, he said.
“Already, I think there’re a thousand different fish living on them. There’re lobsters, there’re big schools of angelfish. And there’s a big coating of algae, which is one of the [first] things to settle.”
A Way to Recycle
Along the Atlantic coast from New Jersey to Georgia, subway cars—along with armored tanks, naval ships, tugboats, and a large number of concrete culverts—have been strategically dumped in the ocean to act as artificial reefs. Most of the mid-Atlantic ocean surface is featureless sand punctuated with mud splotches, so the artificial reefs help boost marine life and, by extension, keep recreational fishers happy.
Cast of Characters
The people in “The Silent Evolution” were created from live casts of a wide sample of people, most of them locals—including Lucky a Mexican carpenter; a 3-year-old boy, Santiago; and an 85-year-old nun, Rosario. Also depicted are an accountant, yoga instructor, and acrobat, among others.
“Sarah,” modeled after a U.K. linguistics professor, is the only “Silent Evolution” statue with a false lung, according to Taylor. Divers can either fill the lung by blowing bubbles into a hole on her back or using air from their tanks. The air then slowly escapes though the opening in her mouth.
The tight gathering of people is meant t
o illustrate “how we are all facing serious questions concerning our environment and our impact on the natural world,” according to a museum statement.
Bottom Dwellers
The sculptures were lowered into the waters off Cancún in late 2010. There, they sit in just 30 feet (9 meters) of water, which allows visitors in glass-bottomed boats to observe the artwork, according to a museum statement. Boatbound visitors can also see big schools offish above the statues, Taylor said. “If there’re any sorts of predators or any danger, [the fish] sort of drop below and then hide out in the [statues’] feet area.”
TRUTH:
UPON THE INSTALLATION’S COMPLETION, THE WEIGHT OF THE STATUES WILL TOTAL MORE THAN 180 TONS.
The builders of “The Silent Evolution” hope to usher in a new age of responsible tourism in the area, according to the museum. MUSA, the underwater museum, plans to add sculptures as funding becomes available. But “The Silent Evolution” won’t ever really be finished, since marine life will continue adding its own touches for centuries.
The cement figures will change in appearance in time as coral and other marine life takes over—all part of Taylor’s vision. “The manifestation of living organisms cohabiting and ingrained in our being is intended to remind us of our close dependency on nature and the respect we should afford it,” according to a museum statement.
