Ocean Exploration, Without The Claustrophobic Submarine

Google Earth is a magnificent production- you can virturally tour the whole world from a computer chair. Or so everyone thought, until one Sylvia Earle pointed out the major flaw in this idea. “My children, my grandchildren think it is great to see their backyard, fly through the Grand Canyon, visit other countries,” she said to John Hanke one day at a conference. Hanke happened to be the Director of Google Earth and Maps, and Earle had a bone to pick with him. “But, John, when are you going to finish it? You should call Google Earth ‘Google Dirt’. What about the ¾ of the planet that is blue?”

Sylvia Earle is an oceanographer and explorer, currently a National Geographic Explorer-In-Residence, formerly the chief scientist at the National Oceanic and Atmospheric Administration (NOAA) and recipient of 22 honorary degrees. She is a well-traveled aquanaut, diving in subs and scuba gear many times over, setting records for depth, including a solo sub dive to 1000 meters. Earle has spent her many decades studying the ocean and watching it change, and many countries and organizations have awarded her their highest honors. She has some serious credits. Earle had just met Hanke at a conference in Spain. “I had a chance publicly to say how much I love Google Earth,” she wrote later. And to point out that the then-current version of Google Earth was not complete. She wanted the vicarious exploring to extend to “the real Hawaiian islands, not just the mountain tops that poke through the ocean’s surface.”

Read the rest of this entry »

Advertisements

Great Moments in Earth History: The Hadean

No complete rocks have survived to tell of the formative years following Earth’s formation some 4.56 billion years ago. The material that would have existed at that time has been broken apart by the power of wind and water. It has melted and metamorphosed under the immense pressure and heat deep within Earth’s interior. It has been recycled back on to the surface. It has existed at every stage of the rock cycle many, many times over.

Despite the thousands of millions of years Earth’s earliest material has encountered, tiny pieces of some of these rocks still exist. Small microscopic grains of a mineral, once part of rocks that would have witnessed Earth as it existed just a couple of hundred million years after its formation, survive to this day.

A black and white image of a zircon crystal

A polished section of the oldest known piece of Earth. Credit: NASA

The oldest known terrestrial material is a single grain of a mineral called zircon which was found in the Jack Hills formation in western Australia. It is 4.4 billion years old. The grain itself was part of a rock composed of the broken and eroded bits of other ancient material that itself has been subject to billions of years of geologic reworking.

Zircon is an extremely rugged mineral made up of silicon and the obscure element zirconium. Its tenacity in the face of time and its ability to provide scientists with enough information to figure out the age when it was formed are among the many reasons it is exciting to geologists. Read the rest of this entry »


Counting the Fish in the Sea

The 2010 US census workers had a tough job, but at least they were on land, counting residents with home addresses. 2010 was also the year a group of marine biologists completed a much tougher assignment: a global canvass of ocean residents who don’t fill out forms, live in some of the most remote places on the planet, and often move thousands of miles in a single year. The first study of its scope, the Census of Marine Life has added thousands of new species to the books, and has shown, in the words of project director Jesse Ausubel, that “the ocean’s even richer in diversity than anybody had known.”

The newly discovered Kiwa hirsuta, also known as the Yeti crab. Image courtesy of Chris Allen and the Encyclopedia of Life.

Census scientists collected over 6,000 new species, and have already described 1,200 of them in detail. They discovered deep-sea jellyfish, 500-year-old tubeworms, bejeweled copepods and isopods, and a hairy white crab that lives near sulfurous vents on the ocean floor. They found a mat of filamentous bacteria the size of Greece off the coast of Chile, and located a squid previously believed to have gone extinct in the Jurassic. The Census uncovered new life forms even in some of the world’s most studied and heavily trafficked ocean regions, said Ausubel, Census co-founder and program director at the Alfred P. Sloan Foundation, who described the results in a talk in Washington, DC last Thursday.

Each newly discovered species now has its own web page in the online Encyclopedia of Life, which will eventually catalog every known life form on Earth. Pages in the encyclopedia include physical descriptions of the species, scientific information like where the creature is found and how common it is, and, of course, color photos. “It’s like facebook,” Ausubel said. In addition, scientists gathered DNA from every creature found, new or not, for a project called the International Barcode of Life. The iBOL is a reference library made of segments of specific genes that are shared among many forms of life, but whose precise sequence varies in an identifiable way from species to species.

Scientists also learned that many familiar marine animals make long-distance trips across the ocean, “commuting like jetset businessmen” in Ausubel’s words. Census researchers attached acoustic tags to various creatures and released them; the tags then emitted sounds that were picked up by receivers on the ocean floor as the animals passed by. Scientists watched bluefin tuna swim from Mexico to Japan and back in a year, and tracked seals fishing from underwater mountains off the Antarctic coast. They monitored salmon swimming up the west coast of Canada, and learned that many of them don’t make it back to rivers to spawn the next year. And they used the tags to collect data beyond just the animals’ locations; for example, they enlisted leatherback turtles to collect ocean temperature readings during their journeys around the South Pacific. “Animals connect the ocean in incredible ways,” said Ausubel.

Surveying the astounding diversity of marine habitats—coastlines, continental shelves, deep-sea trenches and mountain ranges, the vast open ocean—required a correspondingly varied array of exploratory techniques: “a concerto of technologies,” said Ausubel. To explore the ocean surface and shallow waters, scientists worked from submarines, airplanes, and massive research vessels. For probing the deep ocean, they turned to robotic and remotely controlled vehicles that could operate at depth without risk to human life. In total, the project cost $650 million spread over a decade, and involved almost 3,000 scientists. “Marine biology hasn’t had a tradition of big science” like physics has, said Ausubel, but with the Census of Marine Life, that may be starting to change.

Bathykorus bouilloni, a deep-sea jellyfish. Image courtesy of Kevin Raskoff.

Although Ausubel noted that “extinction is rare in the ocean,” scientists found ample evidence of humans’ effects on life in the sea, few of them good. Overharvesting has depleted the populations of various fish, mammals, and reptiles since the time of the Romans, and in recent times has led to explosions of less desirable creatures, like jellyfish. Modern scourges like the huge floating garbage patches in the Atlantic and Pacific are also harming aquatic life, particularly island-nesting birds that are often found dead with plastic in their stomachs. But the greatest impacts may be yet to come, as humans increase shipping, oil drilling, and underwater communication, and as rising greenhouse gas emissions continue to warm the ocean and make it more acidic. The Census has given scientists a valuable baseline against which to measure future changes to the abundance and distribution of ocean dwellers.

Despite their impressive findings, marine biologists have just begun the hard part of counting every creature in the sea. They believe the ocean could contain a million or more undiscovered species, most of which are likely to be small, rare, and hard to find. And those are just the relatively well-studied multi-cellular ocean dwellers; the number of microbial species in the ocean is far larger, perhaps as many as a billion. Ausubel also noted that few people study most marine life forms, besides the well-known ones like fish and mammals (a hint to any young scientists out there searching for a specialty.)

The seas have long fascinated and mystified us. Over 60 years ago, Rachel Carson’s best-selling book The Sea Around Us told the public about the stunning discoveries in marine biology made possible by World War 2-era innovations in sonar and submarine technology. Since then we have learned much about what lives in the deep sea, and we now know the ocean floor is not barren but in fact teems with strange and wonderful life. But the Census of Marine Life also reaffirms the lure of the unknown that Carson described in her 1951 masterpiece: “We can only sense that in the deep and turbulent recesses of the sea are hidden mysteries far greater than any we have solved.”