Discovery

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excitement of discovery at Washington State University.

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Archive for the ‘Earth sciences’ Category

Wind from East, Snowy Weather from the West

The crack weather observers employed by WSU Discovery noticed an odd phenomenon this morning: a biting wind blowing from the east outside our Pullman field station, while forecasters say our first snow of the year could come out of the west.

Flickr image of windblown Palouse snow from Kamiak Butte courtesy of Roger Lynn--http://www.flickr.com/photos/rogerlynn/

It did not make sense that weather would move into the wind. Seeking clarification, we first went to the National Weather Service’s forecast discussion, a consistent source of wonky weather detail. No luck.

So we tapped Gerrit Hoogenboom, the relatively new director of Washington State University’s Agricultural Weather Network, AgWeatherNet. He passed our query to Nic Loyd, AgWeatherNet meteorologist. Here’s his ‘splanation, with a bonus comment on today’s forecast:

Yes, there is a storm system and a trough of low pressure approaching from the west today. However, winds are out of the east and southeast in many places such as Pullman this morning. Often in Washington during the late fall and winter, as low pressure approaches the coast from the west, the winds have an easterly component since wind at the surface often blows toward lower surface pressure.  Also, in eastern Washington during the late fall and winter, the surface land is cooler than the air near the warmer offshore water, especially in the morning, and so cold, heavy air moves toward the warmer, lighter, rising air to the west. Behind the cold front, the winds often switch to westerly or southwesterly.

Another way to look at it is that during November when the atmosphere is often stable with a weaker sun, winds behave differently at different heights, and surface winds do not always mix with winds higher in the atmosphere, especially at night. Therefore, winds aloft will be out of the southwest today, but winds were out of the southeast and east this morning in the lowest levels of the atmosphere only.

By the way, it does look as if the weather pattern will be cooler during the day through at least the weekend, but little if any snow is expected in the eastern Washington lowlands. There is not a lot of moisture with tonight’s weather system, however, the mountains should receive a few inches of snow.

 

Plate tectonics key to life on Earth?

Tectonic plates. Courtesy US Geological Survey

Tectonic plates. Courtesy US Geological Survey

Is our vital blue planet the last of its kind?  Or has it always been one of a kind?  From the perspective of post-modern geologists, planet Earth is like no other solar body yet discovered.

“I think when you live on the Earth, you take it for granted,” says Katie Cooper, who thoughtfully considers such esoteric questions for a living. As one of a relatively new group of geologists who use computer simulations to study the thermal and tectonic evolution of our planet, her viewpoint is decidedly celestial.

Cooper, assistant professor in the School of Earth and Environmental Sciences, studies the broad area of geodynamics—particularly the evolution of Earth as a planetary system. Specifically, she models how the three main layers of our planet—core, mantle, and crust (lithosphere)—interact and change over time.

“I look at the Earth as a giant heat engine which drives all of the geologic activity we see at the surface,” she says. “In the past, the core was hotter than it is today. The planet is slowly cooling and that affects everything on the lithosphere.”

That cooling takes place in large part through thermal convection. Like boiling water or the slow movement of oil blobs in a lava lamp, hot plastic rock from the Earth’s mantle is constantly rising toward the surface, where heat and energy are released in hot springs, earthquakes, or volcanic eruptions. At the same time, cooler rock is sinking toward the interior core.

This steady interplay leads to the phenomenon of plate tectonics where vast puzzle-like sections of Earth’s crust “float” on top of hot rock in the mantle—and imperceptibly migrate across the globe.

Earth stands alone

Although plate tectonics is often taken for granted as standard planetary modus operandi, it turns out that Earth is a world apart from other planets.

“Plate tectonics is unique to Earth as far as we know right now,” says Cooper. “The big question is if this is unique to our solar system? Our galaxy?  The universe?”

Not only unique, but possibly essential to life itself. Through its part in cooling the planet’s interior, plate tectonics allows Earth to maintain a magnetic field that shields our world from dangerous solar radiation and, in effect, creates a safe haven for life to flourish. Which presents Cooper with another question—did plate tectonics create optimal conditions for the initial occurrence of life?  No one knows for sure.

Plate tectonics—the next generation

For the first half of the twentieth century, geologists suspected that Earth’s continents had once formed a single land mass before breaking up and drifting aimlessly apart. The continental drift hypothesis was backed up by fossil evidence but no one could explain the actual physical processes driving it.

That changed in 1963, however, when Princeton professor, Harry Hess, used WWII submarine-hunting technology to discover unusual magnetic polarity in the ocean floor. It was concluded that hot rock from the mantle was rising up through the lithosphere and pushing the sea floor—and the continents on either side—apart.

This finding provided the mechanism to explain the purposeful movement of Earth’s plates and led to the development of the first theory of plate tectonics.

Today Cooper is among a new generation of geologists who study what could be called “post” plate tectonics. Taking the field up a notch, she investigates similar processes on other planets and asks why Earth has plate tectonics in the first place.

“Is it the preferred mode of operation?” she asks. “Does it help the planet lose heat most efficiently? Is it a coincidence?”

Using a computer cluster of 600 processors working together as a single unit, Cooper attempts to unlock these mysteries by crunching enormous calculations that often run days or weeks to generate results.

Doing these “paper and pencil calculations” as she refers to them, Cooper builds computer models of planets and applies basic laws of physics to see if the theories are applicable.

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The Slime that Saves the Planet

Washington State University researchers have received half a million dollars to study a microscopic slime that they believe plays an outsized role in life on the planet.

The slime, also known as biofilm, forms a super-thin layer gluing the roots of plants to mineral surfaces and serves as a reactor in which a plant can break down the rock for vital nutrients. The process, says Kent Keller, was central to the start of land-based plant life as plants invaded the continents 350 million years ago. It continues to take place on modern volcanic ground and receding glaciers—anywhere a plant can’t get enough to eat.

A special root slime helps plants like this pine tree pull nutrients from bare rock. Flickr photo courtesy of eviltomthai.

“The magic of all of this is plants come in that are adapted to make the slime,” says Keller, co-director of the Center for Environmental Research, Education, and Outreach (CEREO) and professor in the School of Earth and Environmental Sciences. “Within 100 years, you’ve got soil. That’s an amazing thing. And it’s these slimes that are a key part of the mechanism.”

Wait, there’s more: The biofilm reactor also facilitates the most fundamental process on the planet for packing away carbon, as seen in the greenhouse gas carbon dioxide. As the plant dissolves minerals, the plant’s natural carbonic acids, made from CO2 through photosynthesis, are transformed into bicarbonate that is carried in runoff to the oceans. There it precipitates as calcium carbonate.

In other words, the biofilm acts as an intermediary between carbon from the atmosphere and its storage in the earth’s crust. Absent that process, carbon dioxide would continue building up in the atmosphere until oxygen-dependent life forms suffocated in a “runaway greenhouse.”

“Without that we wouldn’t be here,” says Keller. “We’d be Venus, because Venus has no mechanism to sequester volcanic CO2.”

But there’s a mystery to the process, which Keller and a group of colleagues will explore with $492,000 from the National Science Foundation. Somehow plants employ biofilms to build up nutrients for plants to use while also releasing them for long-term storage, and they’ve done this in a way in which plants thrive and the chemistry of oceans and the atmosphere is kept in balance.

The researchers—a team of earth, life, and soil scientists—plan to grow trees in different nutrient conditions, including pure sand, to see which are best at inducing the formation of biofilm. One indicator of that will be microbial communities, which essentially generate the biofilms for shelter. The researchers hypothesize that plants in the worst conditions will be predisposed to hosting the most diverse microbial communities, the better to generate slime and nutrients.

One experiment will rely entirely on fertilized irrigation as a proxy for conventional agriculture, which is less reliant on large microbial communities for nutrients. Comparing this system with those generating their own nutrients could help open the door to agricultural systems that can use fewer artificial fertilizers.

WSU Geochemist Filing Far-flung Dispatches for The New York Times

In Evelyn Waugh’s Scoop, pretty much the greatest novel ever written about journalism, William Boot is sent to cover an African civil war with a ton of baggage, including a canoe and a cleft stick to carry his dispatches. The cleft stick has since become a metaphor for far-flung journalistic enterprise and the lengths a reporter will go to get a story back to the home office.

Cold and scenic: WSU geologist Jeff Vervoort took in this view recently on a trip to the striking Koettlitz Glacier.

Instead of a cleft stick, Jeff Vervoort has a laptop and a “very, very small bandwidth,” text-only connection from the Central Trans Antarctica Mountain field camp at Antarctica’s Beardmore Glacier field station. That’s about halfway between the McMurdo Station, the continent’s largest community, and the South Pole.

Where William Boot sent brief, easily misinterpreted telegrams to the Beast, Vervoort is filing for the New York Times’ “Scientist at Work” blog. Times editor James Gorman launched this modern version of the old field journal earlier this year “to give scientists in the field a chance to describe what they do as they are doing it.”

“I am obviously thrilled,” says Vervoort, who majored in English as an undergraduate and now specializes in dating rocks by their chemical signatures.

The first dispatch, by colleague and University of Minnesota-Duluth geoscientist John Goodge, went up on the Times site yesterday. Vervoort and Goodge are now scheduled to have alternate posts as their team spends the next five weeks gathering rock samples over about 1,000 miles.

Logistical challenges aside, it’s not hard to interest people in Antarctic science, Vervoort says in a recent email to Pullman:

“This place appeals to many people on so many levels for many reasons. It is the land of extremes (they  like to call Antarctica the coldest, windiest, and driest place on Earth) as well as unknowns.”

The continent also has an ancient story to tell about climate change, he says.

“Many people think of Antarctica as an ice covered continent and couldn’t imagine it any other way.  But 40 million years ago or so there were not permanent ice sheets on Antarctica, during a period of extreme global warming.  The best guess is that these started forming 35-40 million years ago. Sitting up here at the edge of the polar plateau in the austral summer with temperatures a little below zero degrees F and a stiff wind blowing, however, it is hard to imagine that Antarctica warming up any time soon.”

Blogger/researchers Jeff Vervoort, left, and John Goodge enjoy t-shirt temperatures before heading out on the ice.

The research can also tell an even older story about the earth’s crust, says Goodge in the first “Scientist at Work” post:

“Antarctica was a key piece in Pangea, Gondwana and Rodinia (huge supercontinents formed by the assembly of many of today’s familiar continents at roughly 250, 500 and 1,000 million years ago), and knowing more about its geologic architecture can help to refine the picture of global paleogeography as far back as 1 billion years ago.”

For more on Vervoort’s trip, see our previous post, “Journey to the Bottom of the Earth.”

Update–A few hours after this was posted, Vervoort’s first blog went up on the Times site. Here’s an excerpt:

It is probably impossible to prepare yourself before getting here for what to expect from this large ice-covered continent at the bottom of the world. Like many people, I have seen pictures and videos of Antarctica. I am also familiar with different scientific aspects of Antarctica’s oceans, climate and geology, and I had talked about this trip extensively with John Goodge, the leader of the current expedition, before coming down here. But nothing completely prepares you for this place.

Read more…