THE MUTANT PIGEON GENE

Victoria Crown Pigeon.  Credit:  Wikimedia Commons.

FROM: NATIONAL SCIENCE FOUNDATION
Mutant Gene Responsible for Pigeons' Head Crests
Decoded genome reveals secrets of pigeon traits and origins
January 31, 2013

Scientists have decoded the genetic blueprint of the rock pigeon, unlocking secrets about pigeons' Middle East origins, feral pigeons' kinship with escaped racing birds and how mutations give pigeons traits like feather head crests.

"Birds are a huge part of life on Earth, but we know surprisingly little about their genetics," says Michael Shapiro, one of the study's two principal authors and a biologist at the University of Utah.

In the new study, "we've shown a way forward to find the genetic basis of traits--the molecular mechanisms controlling animal diversity in pigeons," he says. "Using this approach, we expect to be able to do this for other traits in pigeons, and it can be applied to other birds and many other animals as well."

The findings appear in a paper published this week in the online journal Science Express.

Shapiro conducted the research with Jun Wang of China's BGI-Shenzhen (formerly Beijing Genomics Institute) and other scientists from BGI, the University of Utah, Denmark's University of Copenhagen and the University of Texas M.D. Anderson Cancer Center in Houston.

"The research identified the genes contributing to variation in the avian head crest, using the domesticated pigeons that so fascinated and inspired Charles Darwin in developing his theory of natural selection," says George Gilchrist, program director in the National Science Foundation's (NSF) Division of Environmental Biology, which funded the research. "This finding illustrates the power of comparative genomics."

Pigeons were domesticated some 5,000 years ago in the Mediterranean region. Key results of this study include sequencing of the genome of the rock pigeon Columba livia, which is among the most common bird species.

There are some 350 breeds of rock pigeons--all with different sizes, shapes, colors, color patterns, beaks, bone structure, vocalizations and arrangements of feathers on the feet and head--including head crests in shapes known as hoods, manes, shells and peaks.

The pigeon's genetic blueprint is among the few bird genomes sequenced so far, along with those of the chicken, turkey, zebra finch and a common parakeet known as a budgerigar or budgie. "This will give us new insights into bird evolution," Shapiro says.

Using software developed by paper co-author Mark Yandell, a geneticist at the University of Utah, the scientists revealed that a single mutation in a gene named EphB2 causes head and neck feathers to grow upward instead of downward, creating head crests.

"This same gene in humans has been implicated as a contributor to Alzheimer's disease, as well as prostate cancer and possibly other cancers," Shapiro says, noting that more than 80 of the 350 pigeon breeds have head crests, which play a role in attracting mates in many bird species.

The researchers compared the pigeon genome to those of chickens, turkeys and zebra finches. "Despite 100 million years of evolution since these bird species diverged, their genomes are very similar," Shapiro says.

A genome for the birds, a gene for head crests

The biologists assembled 1.1 billion base pairs of DNA in the rock pigeon genome; the researchers believe there are about 1.3 billion total, compared with 3 billion base pairs in the human genome. The rock pigeon's 17,300 genes compare in number with the approximately 21,000 genes in humans.

The researchers first constructed a "reference genome"--a full genetic blueprint--from a male of the pigeon breed named the Danish tumbler.

Shapiro says the study is the first to pinpoint a gene mutation responsible for a pigeon trait, in this case, head crests.

"A head crest is a series of feathers on the back of the head and neck," Shapiro says. "Some are small and pointed. Others look like a shell behind the head; some people think they look like mullets. They can be as extreme as an Elizabethan collar."

The researchers found strong evidence that the EphB2 (Ephrin receptor B2) gene acts as an on-off switch to create a head crest when mutant, and no head crest when normal.

They also showed that the mutation and related changes in nearby DNA are shared by all crested pigeons, so the trait evolved just once and was spread to numerous pigeon breeds by breeders.

Full or partial genetic sequences were analyzed for 69 crested birds from 22 breeds, and 95 uncrested birds from 57 breeds. The biologists found a perfect association between the mutant gene and the presence of head crests.

They also showed that while the head crest trait becomes apparent in juvenile pigeons, the mutant gene affects pigeon embryos by reversing the direction of feather buds--from which feathers later grow--at a molecular level.

Other genetic factors determine what kind of head crest each pigeon develops: shell, peak, mane or hood.

Tracking the origins of pigeons

A 2012 study by Shapiro provided limited evidence of pigeons' origins in the Middle East and some breeds' origins in India and indicated kinship between common feral or free-living, city pigeons and escaped racing pigeons.

In the new study, "we included some different breeds that we didn't include in the last analysis," Shapiro says. "Some of those breeds only left the Middle East in the last few decades. They've probably been there for hundreds if not thousands of years. If we find that other breeds are closely related to them, then we can infer those other breeds probably also came from the Middle East."

The scientists found that the owl breeds--pigeon breeds with very short beaks that are popular with breeders--likely came from the Middle East. They're closely related to breeds from Syria, Lebanon and Egypt.

The research also uncovered a shared genetic heritage between breeds from Iran and breeds likely from India, consistent with historical records of trade routes between those regions. People were not only sharing goods along those routes, but probably also interbreeding their pigeons.

As for the idea that free-living pigeons descended from escaped racing pigeons, Shapiro says his 2012 study was based on "relatively few genetic markers scattered throughout the genome. We now have stronger evidence based on 1.5 million markers, confirming the previous result with much better data."

The scientists analyzed partial genomes of two feral pigeons: one from a U.S. Interstate-15 overpass in Utah's Salt Lake Valley, the other from Lake Anna in Virginia.

"Despite being separated by 1,000 miles, they are genetically very similar to each other and to the racing homer breed," Shapiro says.

"Darwin used this striking example to communicate how natural selection works," he says. "Now we can get to the DNA-level changes that are responsible for some of the diversity that intrigued Darwin 150 years ago."

The study's co-authors from the University of Utah include Yandell, Eric Domyan, Zev Kronenberg, Michael Campbell, Anna Vickery and Sydney Stringham; Chad Huff is a co-author from the University of Texas.

The study was also funded by the Burroughs Wellcome Fund, the University of Utah Research Foundation, the National Institutes of Health and the Danish National Research Foundation.

-NSF-

GOING DEEP BENEATH ANTARTIC ICE TO EXPLORE NEW WORLDS

Photo:  Lake In Anatartica. Credit:  NASA-Ames. Chris McKay.

FROM: NATIONAL SCIENCE FOUNDATION

In a Scientific and Engineering Breakthrough, NSF-funded Team Samples Antarctic Lake Beneath the Ice Sheet
Samples may contain microbes from an ecosystem isolated for thousands of years, with implications for the search for life elsewhere in extreme environments

January 28, 2013
In a first-of-its-kind feat of science and engineering, a National Science Foundation (NSF)-funded research team has successfully drilled through 800 meters (2,600 feet) of Antarctic ice to reach a subglacial lake and retrieve water and sediment samples that have been isolated from direct contact with the atmosphere for many thousands of years.

Scientists and drillers with the interdisciplinary Whillans Ice Stream Subglacial Access Research Drilling project (WISSARD) announced Jan. 28 local time (U.S. stations in Antarctica keep New Zealand time) that they had used a customized clean hot-water drill to directly obtain samples from the waters and sediments of subglacial Lake Whillans.

The samples may contain microscopic life that has evolved uniquely to survive in conditions of extreme cold and lack of light and nutrients. Studying the samples may help scientists understand not only how life can survive in other extreme ecosystems on Earth, but also on other icy worlds in our solar system.

The WISSARD teams' accomplishment, the researchers said, "hails a new era in polar science, opening a window for future interdisciplinary science in one of Earth's last unexplored frontiers."

A massive ice sheet, almost two miles thick in places, covers more than 95 percent of the Antarctic continent. Only in recent decades have airborne and satellite radar and other mapping technologies revealed that a vast, subglacial system of rivers and lakes exists under the ice sheet. Lakes vary in size, with the largest being Vostok Subglacial Lake in the Antarctic interior that is comparable in size to Lake Ontario.

WISSARD targeted a smaller lake (1.2 square miles in area), where several lakes appear linked to each other and may drain to the ocean, as the first project to obtain clean, intact samples of water and sediments from a subglacial lake.

The achievement is the culmination of more than a decade of international and national planning and 3 1/2 years of project preparation by the WISSARD consortium of U.S. universities and two international contributors. There are 13 WISSARD principal investigators representing eight different U.S. institutions.

NSF, which manages the United States Antarctic Program, provided over $10 million in grants as part of NSF's International Polar Year portfolio to support the WISSARD science and development of related technologies.

The National Aeronautics and Space Administration's (NASA) Cryospheric Sciences Program, the National Oceanic and Atmospheric Administration (NOAA), and the private Gordon and Betty Moore Foundation also provided support for the project.

The interdisciplinary research team includes groups of experts in the following areas of science: life in icy environments, led by John Priscu, of Montana State University; glacial geology, led by Ross Powell, of Northern Illinois University; and glacial hydrology, led by Slawek Tulaczyk, of the University of California, Santa Cruz.

Sharing of expertise by the groups of disciplinary experts will allow the data collected to be cast in a systemic, global context.

The WISSARD team will now process the water and sediment samples they have collected in hopes of answering seminal questions related to the structure and function of subglacial microbial life, climate history and contemporary ice-sheet dynamics.

Video surveys of the lake floor and measurements of selected physical and chemical properties of the waters and sediments will allow the team to further characterize the lake and its environs.

The approach to drilling was guided by recommendations in the 2007 National Research Council-sponsored report aimed to protect these unique environments from contamination.

A team of engineers and technicians directed by Frank Rack, of the University of Nebraska-Lincoln, designed, developed and fabricated the specialized hot-water drill that was fitted with a filtration and germicidal UV system to prevent contamination of the subglacial environment and to recover clean samples for microbial analyses. In addition, the numerous customized scientific samplers and instruments used for this project were also carefully cleaned before being lowered into the borehole through the ice and into the lake.

Following their successful retrieval, the samples are now being carefully prepared for their shipment off the ice and back to laboratories for numerous chemical and biological analyses over the coming weeks and months.

ANTARTICA AIRCRAFT CRASH : NO SURVIVORS FOUND

FROM: NATIONAL SCIENCE FOUNDATION

Loss of Three Canadian Aircrew Members in Antarctica Is Confirmed
January 28, 2013

On behalf of the U.S. National Science Foundation and all in the U. S. Antarctic Program, I wish to extend our profound sympathies to the families, friends, and colleagues of the three Kenn Borek Twin Otter crew, whose deaths in Antarctica while en route to support the Italian national Antarctic science program have recently been confirmed.

We have been privileged to experience first-hand their professionalism, skill, and dedication to the arduous task of supporting science in an extremely remote and inhospitable environment. In many ways, their contributions make possible hard won but vital advances in scientific knowledge that serve all of mankind. Although everyone associated with the pursuit of science in Antarctica makes personal sacrifices to do so, very infrequently and sadly, some make the ultimate sacrifice.

While it may come as little consolation at this very sorrowful time, the families, friends, and colleagues of the crew members should know that the thoughts of everyone in the U.S. Antarctic Program were with them through the long ordeal of the past few days and remain so now.

To the families and friends of the crew, I commend your loved ones for their commitment and dedication to their profession and offer our condolences. The sense of loss is keenly felt throughout the U.S. program and no doubt throughout the international Antarctic community.

CRASHED IN ANTARTICA: MISSING AIRCRAFT FOUND

FROM: NATIONAL SCIENCE FOUNDATION
January 26, 2013

The wreckage of a Twin Otter aircraft that was reported missing earlier this week in Antarctica has been found in a remote and mountainous area of the continent.

An initial assessment by Kenn Borek Air Ltd. of Calgary, Canada, the owner of the plane, deemed the crash "not survivable."

Weather has prevented search-and-rescue personnel from landing at the site.

The National Science Foundation (NSF), as manager of the U.S. Antarctic Program (USAP), has been cooperating with the Rescue Coordination Centre in Wellington, New Zealand, since the search-and-rescue effort to locate the missing aircraft--a de Havilland DHC-6 Twin Otter--began earlier this week.

Communication with the Twin Otter was lost on Wednesday night, New Zealand time, and search-and-rescue operations have been hampered by bad weather and poor visibility since that time.

The plane was flying in support of the Italian Antarctic Program under the logistical responsibility of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). The aircraft was enroute from NSF's Amundsen-Scott South Pole Station to the Italian research station at Terra Nova Bay when contact was lost.

The three crew members were the only people aboard the plane at the time.

On the afternoon of Saturday, Jan. 26, local time, a ski-equipped LC-130 aircraft--operated by the New York Air National Guard for the USAP and flying from NSF's McMurdo Station--overflew the last known position from the aircraft emergency beacon and spotted the aircraft tail at an elevation of about 3,900 meters (13,000 feet) on Mt. Elizabeth, a 4,480-meter (14,500-foot) summit in the Queen Alexandra Range of the Transantarctic Mountains.

Subsequently, a Twin Otter carrying U.S. and New Zealand search-and-rescue personnel conducted an aerial survey of the site and determined that a landing by fixed-wing aircraft was not possible.

Later, two helicopters--one under New Zealand charter and the other flown for the USAP by PHI, Inc. of Lafayette, Louisiana--arrived at a small camp established roughly 50 kilometers (31 miles) from the crash location to support the operation.

The rescue teams will attempt to reach the site, if conditions permit, before returning to McMurdo Station.

GREENLAND'S PAST CLIMATE CHANGE AND ICE MELT

On March 29, 2011, Operation IceBridge flew between deep canyons and over glaciers along the northwest coast of Greenland. IceBridge, now in its third year, makes annual campaigns in the Arctic and Antarctic where science flights monitor glaciers, ice sheets and sea ice. Image Credit-NASA-Michael Studinger

FROM: NATIONAL SCIENCE FOUNDATION

Analysis of Greenland Ice Cores Adds to Historical Record and May Provide Glimpse into Climate's Future

The International North Greenland Eemian Ice Drilling (NEEM) project results indicate that melting of Antarctic ice sheet may have contributed more to sea level rise than melting of the Greeland ice sheet some 100,000 years ago　

A new study that provides surprising details on changes in Earth's climate from more than 100,000 years ago indicates that the last interglacial--the period between "ice ages"--was warmer than previously thought and may be a good analog for future climate, as greenhouse gases increase in the atmosphere and global temperatures rise.

The research findings also indicate that melting of the massive West Antarctic ice sheet may have contributed more to sea-level rise at that time than melting of the Greenland ice sheet.

The new results from the North Greenland Eemian Ice Drilling (NEEM) project were published in the Jan. 24 edition of Nature.

Members of the research team noted that they were working in Greenland during the summer of 2012 during a rare modern melt event similar to those discussed in the paper.

"We were quite shocked by the warm surface temperatures observed at the NEEM ice camp in July 2012," said Dorthe Dahl-Jensen, of the University of Copenhagen, the NEEM project leader.

"It was simply raining, and, just as during the Eemian period, meltwater formed subsurface ice layers. While this was an extreme event, the present warming over Greenland makes surface melt more likely, and the predicted warming over Greenland in the next 50-100 years will potentially have Eemian-like climate conditions."

The Eemian interglacial period began about 130,000 years ago and ended about 115,000 years ago.

The project logistics for NEEM are managed by Denmark's Centre for Ice and Climate. The Arctic Sciences Section in the National Science Foundation's Division of Polar Programs manages the U.S. support for the project.

In addition to Denmark and the United States, researchers from Belgium, Canada, China, France, Germany, Iceland, Japan, the Netherlands, South Korea, Sweden, Switzerland and the United Kingdom are also partners in NEEM.

The research published this week shows that during the Eemian interglacial, the climate in North Greenland was about 8 degrees Celsius warmer than at present. Despite this strong warming signal during the Eemian--a period when the seas were roughly four to eight meters higher than they are today--the surface in the vicinity of NEEM was only a few hundred meters lower than its present level, which indicates that the Greenland ice sheet may have contributed less than half of the total sea rise at the time.

"The new findings reveal higher temperatures in Northern Greenland during the Eemian than paleo-climate models have estimated," said Dahl-Jensen.

The researchers looked at surface elevation and ice thickness in the early and later parts of the Eemian. Following the previous glacial period, 128,000 years before present, the surface elevation in the vicinity of NEEM was 200 meters higher than the present and the ice thickness decreased at a very high rate of 6 centimeters per year. Some 122,000 years before the present, the surface elevation was 130 meters below the present. In the late Eemian, 122,000 to 115,000 before present, the surface elevation remained stable at a level of 130 meters below the present with an ice thickness of 2,400 meters.

The research team estimated the Greenland ice sheet's volume reduced by no more than 25 percent over 6,000 years. The rate of elevation change in the early part of the Eemian was high and the loss of mass from the Greenland ice sheet was likely on the the same order as changes observed during the last ten years.

"The good news from this study is that Greenland is not as sensitive as we thought to temperature increases in terms of disgorging ice into the ocean during interglacial periods," said Dahl-Jensen. "The bad news is that if Greenland did not disappear during the Eemian, Antarctica, including the more dynamically unstable West Antarctica, must be responsible for a significant part of the 4-8 meters of sea-level rise."

Jim White, director of the Institute of Arctic and Alpine Research at the University of Colorado, Boulder, and the lead U.S. investigator on the NEEM project, said that while three previous ice cores drilled in Greenland in the last 20 years recovered ice from the Eemian, the deepest layers were compressed and folded, making the data difficult to interpret.

With this study, although there was some folding of the lowest ice layers in the NEEM core, sophisticated ice-penetrating radar helped scientists sort out and interpret the individual layers to paint an accurate picture of the warming of Earth's Northern Hemisphere as it emerged from the previous ice age.

"When we calculated how much ice melt from Greenland was contributing to global sea rise in the Eemian, we knew a large part of the sea rise back then must have come from Antarctica," said White. "A lot of us had been leaning in that direction for some time, but we now have evidence that confirms that the West Antarctic ice sheet was a dynamic and crucial player in global sea rise during the last interglacial period."

The intense surface melt in the vicinity of NEEM during the warm Eemian period was seen in the ice core as layers of re-frozen meltwater. Meltwater from surface snow had penetrated the underlying snow, where it re-froze. Such melt events during the past 5,000 years are very rare by comparison, confirming that the surface temperatures at the NEEM site during the Eemian were significantly warmer than today, said the researchers.

The Greenland ice core layers--formed over millennia by compressed snow--are being studied in detail using a big suite of measurements, including stable water isotope analysis that reveals information about temperature and moisture changes back in time. Lasers are used to measure the water stable isotopes and atmospheric gas bubbles trapped in the ice cores to better understand past variations in climate on a year-by-year basis--similar in some ways to a tree-ring record.

"It's a great achievement for science to gather and combine so many measured ice core records to reconstruct the climate history of the past Eemian," said Dahl-Jensen. "It shows what a great team of researchers we have assembled and how valuable these findings are."

JELLYFISH POPULATIONS AND THE ECOSYSTEM

Photo:  Jellyfish.  Credit:  Wikimedia Commons.

FROM: NATIONAL SCIENCE FOUNDATION

Jellyfish "Blooms" Wax and Wane in Natural Cycles
January 24, 2013
Once a month, on the darkest nights near the new moon, otherworldly beings emerge from Pacific Ocean depths and drift onto the beaches of Hawaii.

Hundreds, sometimes thousands, of these quivering masses of jelly float in with the night tide.

Near shore, time grows short to complete their mission: to reproduce, leaving behind miniature versions of themselves fastened with a glue-like substance to reefs and rocks in the shallows.

Box jellyfish, the invaders are called. Over the past few decades, more and more box jellies are in the waters around Hawaii. The question, scientists say, is where are the jellies coming from?

In the marine science world, it's been dogma that jellyfish are increasing in seas and oceans.

Off the coast of France, for example, aggregations of jellyfish have sunk 500-pound fishing nets. And in Japan, jellies have clogged the water intakes of nuclear power plants.

Humans' expanding influence on the oceans has begun to cause changes. "Blooms" of jellyfish are occurring in response to these effects. Or are they?

Jellyfish on the rise--or on the wane?

"There's a perception that jellyfish numbers are exploding in the world's oceans," says marine scientist Rob Condon of the Dauphin Island Sea Lab in Alabama, "but there's no real evidence for a global increase in jellyfish over the past two centuries."

Results of a study of worldwide jellyfish abundance, led by Condon, were recently published in the journal Proceedings of the National Academy of Sciences (PNAS).

The paper's co-authors are scientists affiliated with the Global Jellyfish Group, a consortium of 30 researchers. The Global Jellyfish Group conducted its work at the National Center for Ecological Analysis and Synthesis at the University of California, Santa Barbara.

"It's refreshing to see a thoughtful analysis of the 'jellyfish bloom' phenomenon," says David Garrison, program director in the National Science Foundation's (NSF) Division of Ocean Sciences, which funded the research.

"The findings point out the critical importance of obtaining long-term data to understand the patterns and significance of perceived environmental changes."

The study shows that global jellyfish populations undergo oscillations over decades, including a rising phase in the 1990s and early 2000s that contributed to the perception of an increase in jellyfish abundance.

The previous period of high jellyfish numbers during the 1970s went unnoticed.

"At the time, there was limited research on jellyfish," says Condon, "along with less awareness of global-scale environmental problems, and less information transmitted around the world quickly. We didn't have the Internet."

Long-term observations needed

While there has been no increase in jellyfish blooms over the long-term, the paper's authors say, they detected a hint of a slight increase since 1970.

The trend was countered, however, by the finding that there was no difference in the proportion of increasing versus decreasing jellyfish populations over time.

"Sustained monitoring is required over the next decade to find out if what we're seeing is an actual shift, or if it's part of a larger oscillation," says Condon.

"The research is an important step in our understanding of the complex biological cycles that occur in the oceans," says Henry Gholz, program director in NSF's Division of Environmental Biology, which also funded the research.

"It demonstrates the critical role of long-term observations in informing society of environmental changes."

The idea of a global increase in jellyfish, says Condon, "was fueled by a few local and regional case studies."

"Clearly, there are areas where jellyfish have increased. The situation with Giant Jellyfish in Japan is an example. But there are also places where jellyfish numbers have remained stable, fluctuated over decades, or in fact decreased over time."

He and colleagues say that it's important to sample marine waters over appropriate space and time scales so trends aren't misinterpreted.

"The realization that jellyfish synchronously rise and fall around the world should lead us to search for the long-term natural factors driving jellyfish populations," says Condon.

The ocean brought to life

With tissues made up of 95 percent salts and water, jellyfish are the ocean brought to life.

Washed up on a beach, jellyfish look like ugly gobs of slime. But in the sea, these fragile creatures shimmer with jewel-like radiance.

Their real beauty, though, is their crucial contribution to the functioning of marine ecosystems.

Researchers such as Condon are finding that jellyfish may help us see the complex relationships among species in the oceanic food web.

Jellyfish can live almost anywhere there's water: under the ice in arctic and antarctic seas, and even in North American freshwater lakes and streams, where one tiny species is found.

Most jellyfish are propelled by the rhythmic contraction and expansion of an umbrella-shaped saucer, or bell, as well as by winds, currents and tides. Nearly all are part of a drifting community of organisms called plankton, a term derived from the Greek word for wanderer.

Scientists refer to animal drifters with gelatin-like tissues as gelatinous zooplankton. This group encompasses the familiar bell-shaped jellyfish, related walnut-shaped comb jellies, and similar creatures like siphonophores--chains or colonies of jelly animals.

Many jellyfish live for just one summer. Before they die in September, females release hundreds of eggs into the water, then males release sperm. The resulting larvae swim to the bottom and attach themselves to hard surfaces. In spring they bud into tiny jellyfish, and the cycle begins anew.

Jellies: integral parts of marine ecosystems

Jellies are integral parts of marine ecosystems, says Condon.

They prey on a host of microscopic and larger species, and are themselves food for sea turtles and fish such as the mola, or giant ocean sunfish.

In Alaskan waters, for example, saucerlike moon jellyfish provide nourishment for green sea urchins, crabs and burrowing anemones.

"The question has been: are jellies playing their natural part or hogging the stage?" asks Condon. "Based on recent results, they're doing what jellyfish evolved to do, right on cue."

In addition to Condon, authors of the paper are: Carlos Duarte of the University of the Balearic Islands and the Spanish National Research Council, Esporles, Spain; Kylie Pitt of Griffith University, Australia; Kelly Robinson of the Dauphin Island Sea Laboratory; Cathy Lucas of the University of Southampton, United Kingdom; Kelly Sutherland of the University of Oregon; Hermes Mianzanh of the National Institute of Research and Fisheries Development, Argentina; Molly Bogeberga of the Dauphin Island Sea Laboratory; Jennifer Purcell of Western Washington University; Mary Beth Decker of Yale University; Shin-ichi Uyek of Hiroshima University, Japan; Laurence Madin of the Woods Hole Oceanographic Institution; Richard Brodeur of the NOAA Northwest Fisheries Science Center; Steven Haddock of the Monterey Bay Aquarium Research Institute; Alenka Malejo of the National Institute of Biology, Piran, Slovenia; Gregory Parry of the Department of Primary Industries, Victorian Fisheries, Queenscliff, Australia; Elena Eriksenq of the Institute of Marine Research, Bergen, Norway; Javier Quiñones of the Institute of the Sea of the Peru, Paracas, Ica, Peru; Marcelo Achah of the National Institute of Research and Development fisheries, Mar del Plata, Argentina; Michel Harveys of the Maurice Lamontagne Institute, Fisheries and Oceans, Canada; James Arthur of Griffith University in Australia; and William Graham of the University of Southern Mississippi.

Cheryl Dybas, NSF

　

　

　

ANTARTIC SEARCH AND RESCUE MISSION UNDERWAY

Photograph by: Spencer Klein, NSF

FROM: NATIONAL SCIENCE FOUNDATION

NSF Cooperating with Italy, New Zealand in Search for Downed Plane in Antarctica

January 23, 2013
Officials with the U.S. Antarctic Program are cooperating with their Italian and New Zealand counterparts, as well as the Rescue Coordination Centre in Wellington, NZ, in a search-and-rescue effort to locate a propeller-driven aircraft that is believed to have crashed in a remote and mountainous part of Antarctica.

A three-person crew is believed to have been aboard the de Havilland Twin Otter when contact was lost with the plane in the early morning hours of Jan. 23, Eastern Standard Time (U.S. stations in Antarctica keep New Zealand time). The nationalities of the crew are unconfirmed at this point.

The missing plane was flying in support of the Italian Antarctic Program under the logistical responsibility of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), and was en route from NSF's Amundsen-Scott South Pole Station to the Italian research station at Terra Nova Bay when contact was lost with the aircraft in a remote region of the Transantarctic Mountains.

The aircraft is owned and operated by Kenn Borek Air Ltd., a Canadian firm headquartered in Calgary that charters aircraft to the U.S. program.

Communications between U.S. officials at McMurdo Station in Antarctica and the New Zealand Rescue Coordination Centre confirmed that an emergency locator beacon had been activated.

Officials are monitoring conditions at the site, where the weather is currently very poor, to decide when to launch a search of the area and what kind of aircraft to use.

The National Science Foundation (NSF) manages the U.S. Antarctic Program through which it coordinates all U.S. scientific research on the southernmost continent and in the surrounding Southern Ocean as well as providing the necessary logistical support for the science.

MOUNTAINS, FIRE AND WATER

An aerial view of the Colorado Rocky Mountains.  Credit:  Wikimedia Commons.

 
FROM: NATIONAL SCIENCE FOUNDATION

High-Peak Creeks, Forest Fires and Landscape Erosion: Could They Be Linked?

Fire and water. One scorches the other, only to be drowned in return. Could their effects on a watershed be related?

Scientists conducting research in Colorado's Rocky Mountains at the National Science Foundation (NSF) Boulder Creek Critical Zone Observatory (CZO) are finding out.

Boulder Creek is a 31-mile-long stream draining the Rocky Mountains to the west of Boulder, Colo., as well as the city itself and surrounding plains.

At the Boulder Creek CZO, scientists see fire and water as being closely tied to the landscape--and to what's below that landscape in the subsurface environment.

"Ultimately, it's the landscape that controls where fires are most likely," says scientist Suzanne Anderson of the University of Colorado at Boulder, director of the Boulder Creek CZO.

"It all begins with the presence of the mountains," she says, "with the landscape beneath the forests and streams."

The Colorado Front Range, whose mountains Boulder Creek plummets down, are the stage upon which fire, water and forests are set.

Take the Fourmile Canyon Fire of September 2010. It burned 6,400 acres, destroyed 169 homes and caused more than $217 million in damages.

The wildfire raged through the Boulder Creek watershed's rugged terrain. The resulting deforestation, CZO scientists have found, left the area at risk of flooding and erosion, including debris flows from the fire.

NSF's Critical Zone Observatories: where rock meets water meets life

The Boulder Creek CZO is one of six NSF CZOs in watersheds across the nation.

In addition to the Boulder Creek site, CZOs are located in the Southern Sierra Nevada, Christina River Basin on the border of Delaware and Pennsylvania, Susquehanna Shale Hills in Pennsylvania, Luquillo riparian zone in Puerto Rico, and the Jemez River and Santa Catalina Mountains in New Mexico and Arizona.

They're providing researchers with a new understanding of the critical zone--the region between the top of the forest canopy and the base of unweathered rock.

"The critical zone is our living environment," says Enriqueta Barrera, program director in NSF's Division of Earth Sciences, which funds the CZO network. "The CZOs offer us new knowledge about the critical zone and its response to climate and land-use change."

They're the first systems-based observatories dedicated to understanding how Earth's surface processes are coupled, she says. "They will help us predict how the critical zone affects the ecosystem services on which society depends."

The water cycle, the breakdown of rocks and eventual formation of soil, the evolution of rivers and valleys, patterns of plant growth and landforms all result from processes that take place in the critical zone.

"The CZOs," says Barrera, "are fostering a new view of the critical zone as one holistic system."

Fast-moving water--and fire--in the critical zone

What are the long-term effects of the Fourmile Canyon Fire and other wildfires on watersheds such as Boulder Creek?

Studies of streams after wildfires have yielded conflicting results. Some show increases in pH (water that's more basic vs. acidic), turbidity, nutrients, sulfate and metals. Other research reports few effects.

"Many of these studies sampled water chemistry at intervals that didn't catch rapid changes," says Anderson. "At the Boulder Creek CZO, we're conducting high-frequency stream sampling, and evaluating how upland hydrologic and biogeochemical processes affected by fire influence downstream water quality."

Since the Fourmile Canyon Fire, scientists at the Boulder Creek CZO and the U.S. Geological Survey have been tracking discharge rates, nutrients, metals and ecosystem characteristics such as numbers and species of invertebrates that live in streams.

Runoff from burned north- and south-facing slopes is being measured to assess how hillslopes respond differently following fire.

Instruments have been placed on the hillslopes, and in soils along Boulder Creek's banks, to record changes. Stream water and soil chemistry are being compared with those of nearby unburned areas.

Monitoring continues during snowmelt when water levels are high, and during "gully washer" summer thunderstorms.

In the summer of 2011, for example, a severe storm led to an 8,100 percent increase in stream discharge in Fourmile Creek, a tributary of Boulder Creek. "That was some three times higher than had ever been measured," says Anderson.

The storm flooded homes and blocked roads with sediment. It also resulted in concentrations of in-stream total suspended solids that were 4,000-fold above baseline.

Some of that sediment remains in the creek channel, then flows downstream when more rain falls in the area.

"Such precipitation events can lead to catastrophic erosion that affects long-term sediment loads," says Anderson. "Increases in turbidity, nitrate and what's called dissolved organic carbon in turn may affect drinking water treatment processes."

These studies are but a few of "many taking place at the Boulder Creek CZO on everything from how the 'architecture' of the critical zone affects its hydrology, to the role trees play in the critical zone's evolution," says Anderson.

The Front Range: a regional water tower

With its high peaks, the Colorado Front Range "harvests" precipitation from the atmosphere. Most of that precipitation falls as snow. The snowpack becomes a reservoir, and the mountains act as a water tower.

"The distribution of water resources in western North America is actually controlled by the geologic history of the region," says Anderson. "It sets the location, height and width of the moisture-trapping and moisture-holding mountain ranges."

Forests near Boulder Creek--and everywhere in the West--are found in mountain ranges. Moisture is high enough there for trees to flourish, and precipitation evaporates more slowly.

But where forests grow, fires often aren't far behind. "With more droughts in recent years," says Anderson, "we're more at risk of fires."

The role of erosion

The Front Range--more than 10,000 feet high at its crest--is eroding, says Anderson, but very slowly.

For the most part, "it's cool and moist there," she says, "and 'soil-mantled'--the soil wasn't scraped away by the glaciers that covered the region in the distant past."

Most of this slowly eroding terrain has been sliced by rivers, which have hollowed out deep canyons such as Boulder Canyon.

"The canyons are giant drains carved into the terrain," says Anderson. "They lower the water table of surrounding slopes. Their erosion history sets up broad regions of well-drained forested landscape."

That well-drained landscape is the corridor where big fires, such as the one in Fourmile Canyon, have happened.

"The topography of the Front Range is interconnected with water and fire in the landscape," says Anderson.

Past is prologue?

At Boulder Creek, scientists are looking down into the subsurface, Anderson says, "to understand how the landscape evolved into its present state, and how that controls everything from where forests are found, to how fast weathering of subsurface rock takes place, to a watershed's ability to collect and store water." And, perhaps, to put a fire out.

Meanwhile, the creek flows onward, cutting into the mountain landscape as it goes--and carrying parts of the Rockies with it.

"Amber and white and black in the arrested spaces," wrote H.H. Jackson in 1878 in Bits of Travel at Home, "[Boulder Creek] whirls under bridges and round the corners, doubles on itself, leaps over and high above a hundred rocks in a rod, breaks into sheafs and showers of spray, foams and shines and twinkles and glistens; and if there be any other thing which water at its swiftest and sunniest can do, that it does also, even to jumping rope with rainbows."

A perfect description, says Anderson, of the role of fast-flowing streams in the critical zone.

IN DEEP MAGMA

Credit:  Wikimedia Commons.

FROM: NATIONAL SCIENCE FOUNDATION

Magma in Earth's Mantle Forms Deeper Than Once Thought Study simulating pressures in mantle beneath the ocean floor shows that rocks can melt at depths up to 250 kilometers


Magma forms far deeper than geologists previously thought, according to new research results.

A team led by geologist Rajdeep Dasgupta of Rice University put very small samples of peridotite, rock derived from Earth's mantle, under high pressures in a laboratory.

The scientists found that the rock can and does liquify, at least in small amounts, at pressures equivalent to those found as deep as 250 kilometers down in the mantle beneath the ocean floor.

Dasgupta said that this answers several questions about Earth's inner workings.

He is the lead author of a paper that appears today in the journal Nature. The research was funded by the National Science Foundation (NSF).

"The results show that in some parts of the Earth, melting, or magma formation, happens very deep beneath Earth's surface," said geologist Jennifer Wade, a program director in NSF's Division of Earth Sciences, which funded the research.

"It also means that some carbon dioxide and water could come from different sources--and deeper within the Earth--than we believed."

The mantle is the planet's middle layer, a buffer of rock between the crust--the top five miles or so--and the Earth's core.

If one could compress millions of years of observation of the mantle to mere minutes, the mantle would look like a rolling mass of rising and falling material.

This slow but constant churning convection brings materials from deep within the Earth to the surface, and higher, through volcanic eruptions.

The team focused on the mantle beneath the ocean because that's where crust is created and where, Dasgupta said, "the connection between the interior and surface world is established."

Magma rises with convective currents, then cools and spreads out to form ocean-floor crust.

The starting point for melting has long been thought to be at 70 kilometers beneath the seafloor.

That had confounded geologists who had suspected, but could not demonstrate, the existence of deeper magma, said Dasgupta.

For example, when scientists try to determine the mantle's density, they do so by measuring the speed of a seismic wave after an earthquake, from its origin to other points on the planet.

Because such waves travel faster through solids (e.g., crust) than through liquids (e.g., magma), geologists had been surprised to detect waves slowing down, as though passing through liquid, in a zone that should be the mantle's faster "express lane."

"Seismologists have observed anomalies in velocity data as deep as 200 kilometers beneath the ocean floor," Dasgupta said.

"It turns out that trace amounts of magma are generated at this depth, which would potentially explain that" slower velocity.

The research also offers clues to the electrical conductivity of the oceanic mantle.

"The magma at such depths has a high enough concentration of dissolved carbon dioxide that its conductivity is very high," Dasgupta said.

But, because scientists have not yet been able to sample the mantle directly, researchers have had to extrapolate from the properties of rocks carried up to the surface.

So, in a previous study, Dasgupta determined that melting in Earth's deep upper mantle is caused by the presence of carbon dioxide.

The present study shows that carbon helps to make silicate magma at significant depths. And, the researchers also found that carbonated rock melts at significantly lower temperatures than non-carbonated rock.

"This deep melting makes the silicate differentiation [changes in silicate distribution that range from the dense metallic core, to the less-dense silicate-rich mantle, to the thinner crust] of the planet much more efficient than previously thought," Dasgupta said.

"Deep magma is the main agent that brings all the key ingredients for life--water and carbon--to the surface of the Earth."

In Dasgupta's high-pressure lab, volcanic rocks are windows to the planet's interior. The researchers crush tiny rock samples that contain carbon dioxide to find out how deep magma forms.

"We have all the necessary tools to simulate very high pressures--to nearly 750,000 pounds per square inch--and temperatures," he said. "We can subject small amounts of rock to these conditions to see what happens."

The geologists use powerful hydraulic presses to partially melt rocks that contain tiny amounts of carbon, simulating what they believe is happening under equivalent pressures in the mantle.

"When rocks come from deep in the mantle to shallower depths, they cross . . . the solidus [boundary], where rocks begin to undergo partial melting and produce magmas," Dasgupta said.

"Scientists knew the effect of a trace amount of carbon dioxide or water would lower this boundary, but our new estimation made it 150-180 kilometers deeper from the known depth of 70 kilometers," he said.

"What we are now saying is that with just a trace of carbon dioxide in the mantle, melting can begin as deep as around 200 kilometers.

"When we incorporate the effect of trace water, the magma generation depth becomes at least 250 kilometers."

The extent of magma generation is larger than previously thought, he said, and, as a consequence, has the capacity to affect the geophysical and geochemical properties of the entire planet.

Co-authors of the paper are Ananya Mallik and Kyusei Tsuno at Rice University; Anthony Withers and Marc Hirschmann at the University of Minnesota; and Greg Hirth at Brown University.

The study was also supported by a Packard Fellowship to Dasgupta.

CLEAN AIR COOKING AND HEALTH IN AFRICA

Map:  Ghana.  Credit:  CIA World Factbook.

FROM: NATIONAL SCIENCE FOUNDATION

Discovery
Cooking Up Clean Air in Africa
Reducing air pollution and meningitis risk in Ghana
They're little more than a pile of burning sticks with a stewpot atop them.

But these open fires or basic cookstoves have been linked to the premature deaths of 4 million people annually, many of them young children.

Three billion people around the world rely on wood, charcoal, agricultural waste, animal dung and coal for household cooking needs. They often burn these fuels inside their homes in poorly ventilated stoves or in open fires.

The resulting miasma exposes families to air pollution levels as much as 50 times greater than World Health Organization guidelines for clean air, setting the stage for heart and lung disease.

Household air pollution can also lead to pneumonia in children and low birth weight in infants.

Now researchers believe the smoke may be a contributing factor in bacterial meningitis outbreaks in countries such as Ghana, whose northern region is located in Africa's "meningitis belt."

An estimated 300 million people live in the meningitis belt, which includes part or all of The Gambia, Senegal, Mali, Burkina Faso, Ghana, Niger, Nigeria, Cameroon, Chad, Central African Republic, Sudan, South Sudan, Uganda, Kenya, Ethiopia and Eritrea.

Those exposed to indoor air pollution from cooking over open flames are nine times more likely to contract meningitis, studies show.

Meningitis, a potentially deadly disease, is an inflammation of the membranes covering the brain and spinal cord. Most cases are caused by a viral infection, but bacterial and fungal infections are also culprits. Bacterial meningitis is the most dangerous form.

Outbreaks usually happen in the dry, dusty season, and end with the onset of the seasonal rains.

The dust and dryness may irritate sensitive human membranes, making victims vulnerable to infection. Cooking smoke may play a similar role, increasing susceptibility to meningitis.

"Smoke from cooking practices may irritate the lining of the mucosa, allowing bacteria to become invasive," says Christine Wiedinmyer of the National Center for Atmospheric Research (NCAR) in Boulder, Colo.

Links among cookstoves, air pollution and human health

Wiedinmyer and colleagues have been awarded a grant from the National Science Foundation's (NSF) Coupled Natural and Human Systems (CNH) Program to study the effects of cookstoves in northern Ghana.

CNH is part of NSF's Science, Engineering and Education for Sustainability (SEES) investment, and is supported by NSF's Directorates for Geosciences; Biological Sciences; and Social, Behavioral & Economic Sciences.

The study is breaking new ground by bringing together atmospheric scientists, engineers, statisticians and social scientists.

Researchers are analyzing the effects of smoke from traditional cooking methods on households, villages and entire regions--and whether introducing more modern cookstoves will help.

They hope their findings will reach across the African Sahel, the semi-arid zone between the Sahara Desert in the north and the savannas of Sudan in the south.

Integrating the physical, social and health sciences

"The adoption of more efficient cookstoves could lead to significant improvements in public health and environmental quality," says Sarah Ruth, a CNH program director at NSF, "but research has usually focused on the effects on individual households, local air quality, or the weather and climate system.

"By integrating the physical, social and health sciences, these scientists are providing a more complete analysis of the costs and benefits of improved cookstoves."

An overview of the research was presented at NSF in November, 2012, as part of a forum featuring NCAR research.

The results will provide critical information to policy-makers and health officials in countries where open-fire cooking or inefficient cooking practices are common.

"When you visit remote villages during the dry season," says Wiedinmyer, an atmospheric chemist, "there's a lot of smoke in the air from cooking and other burning practices.

"We need to understand how these pollutants are affecting public health and regional air quality and, in the bigger picture, climate."

To find out, the scientists are using a combination of local and regional air quality measurements; new instruments with specialized smartphone applications that are more mobile than traditional air quality sensors; and computer models of weather, air quality and climate.

"The project involves exploring new technologies to improve human health and well-being while also improving environmental quality," says Tom Baerwald, an NSF program director for CNH.

"By looking at this problem from social, cultural, economic, health and atmospheric science perspectives, these researchers are developing a framework that will help people in many other regions."

Scientists and local communities working together

The scientists are surveying villagers to obtain their views on possible connections between open-fire cooking and disease--and whether community members are willing to adopt different cooking methods.

Cooking fires are a major source of particulates, and of carbon monoxide and other gases that lead to smog.

The fires also emit heat-trapping gases such as carbon dioxide that, when mixed into the global atmosphere, can affect climate.

Widespread use of more efficient, or "clean," cookstoves--which can produce less smoke than open fires--may lower these toxic emissions.

"Newer, more efficient cookstoves could reduce disease and result in improved regional air quality," Wiedinmyer says.

To find out, the scientists are introducing upgraded cookstoves into randomly selected households across the Kassena-Nankana District of Ghana.

In addition to determining whether the clean cookstoves improve air quality and human health, the researchers are exploring the social and economic factors that encourage or discourage such cookstove use.

It takes a village

They're asking villagers for help.

"Community members will assist with measuring air quality and reporting disease," says social scientist Katie Dickinson of NCAR.

Dickinson, Wiedinmyer and others are working with townspeople to develop scenarios in which realistic changes in cooking practices interact with climate processes to improve air quality and reduce respiratory illness and bacterial meningitis.

"We hope this project will alleviate a major health problem," says Mary Hayden, a medical anthropologist at NCAR, "one that extends across the entire Sahel."

ANTARTIC SCIENTIFIC PROGRESS ON ICE

Antartic Lake.  Credit:  NASA.

FROM: NATIONAL SCIENCE FOUNDATION

Trio of Complex Antarctic Science Projects Reaches Significant Technological Milestones "on the Ice"

December 20, 2012

Three very large-scale, National Science Foundation-funded Antarctic science projects--investigating scientifically significant subjects as varied as life in extreme ecosystems, the fate of one of the world's largest ice sheets and the nature of abrupt global climate-change events--have recently each reached important technological milestones that will advance cutting-edge research.

In the past week, researchers with the West Antarctic Ice Sheet Divide (WAIS) project, the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project and the Pine Island Glacier (PIG) project each announced they had achieved these various milestones. In each case, the successes were based on innovative drilling technologies and promise to open new scientific vistas for Antarctic research.

All three projects are supported by the NSF-managed U.S. Antarctic Program (USAP). Through the USAP, NSF coordinates all U.S. scientific research and related logistical support on the southernmost continent and in the surrounding Southern Ocean.

"Although additional challenges doubtless lie ahead for these projects in the harsh Antarctic environment, these successes are a testament to both scientific and engineering ingenuity and the logistical support needed to mount such ambitious and scientifically promising programs," said Scott Borg, who heads Antarctic Sciences in NSF's Office of Polar Programs.

Pine Island Glacier

On December 17, researchers with the PIG project announced that they had successfully drilled through the remote Pine Island Glacier ice shelf.

The successful drilling will help to reach the project's ultimate objective: to study the physical processes that are causing a rapid melting of the 60-kilometer-long (37 miles) ice shelf that extends into Pine Island Bay. One cause is suspected to be the circulation of relatively warmer ocean waters under the floating ice shelf that are undercutting the shelf.

Results from PIG will be used to improve the physics of numerical models that are used to predict future melt rates of the massive West Antarctic Ice Sheet. Increased melting of the ice sheet could contribute significantly to global sea-level rise, with wide-ranging consequences for the Earth's temperate regions.

The stability of the polar ice sheets and their reaction to rising global temperatures remain one of the variables in the models used to predict climate trends. Analysis of satellite imagery and altimetry has shown that this part of the West Antarctic Ice Sheet has the highest thinning rates in Antarctica.

PIG is also funded by the National Aeronautics and Space Administration (NASA) and includes collaborating scientists from the British Antarctic Survey (BAS). High-resolution imagery analyzed by NASA Emeritus and project lead scientist Bob Bindschadler was used to locate a suitable site for the PIG camp on the ice.

The international PIG project is comprised of scientists and engineers with specialized expertise in analyzing satellite imagery deploying the hot-water drill; seismic and radar surveys of the ice shelf; and sea-bed structure and development and deployment of custom-built ocean instrumentation that will be left in the ocean cavity below the ice shelf to measure circulation and ocean-ice interactions over the coming years.

The PIG team faces the challenges of working not only in one of the most remote areas of the continent but also on a heavily crevassed region of the ice shelf where ice-sheet and weather conditions make it extremely difficult to deploy the personnel needed to conduct science, particularly for a large-scale project such as PIG. The project was initially launched as an initiative of the international Polar Year (IPY) 2007-2009 but has had to overcome numerous natural obstacles to deploy this season.

One of the primary tasks for the team has been to use a hot-water drill run by Martin Truffer, of the University of Alaska, Fairbanks, to make two 500-meter-deep (1,600 feet), 20-centimeter-diameter (approximately 8 inches) "skinny holes" through the ice shelf at each measurement site.

Researcher Tim Stanton's group, at the Naval Postgraduate School, developed specialized long-term instrument systems to fit down the 20-centimeter holes. A surface-powered instrument package lowered through the first bore hole to hang two meters (6.5 feet) below the ice measures the boundary layer currents and rate of mixing of ocean water right below the ice, allowing the local ice-melt to be calculated.

Sridhar Anandakrishnan and Leo Peters, geophysicists with Penn State University, meanwhile, are creating tiny "earthquakes" to study the shape of the ocean cavity and the properties of the bedrock under the PIG ice shelf. Leo and Penn State student Kiya Wilson have been doing seismic measurements around the first and second drill camp sites, then, with helicopter support, they will sample about 40 locations across the ice shelf to determine the larger-scale sea-bed shape and ice-shelf structure.

WISSARD

In the same week, meanwhile, researchers with WISSARD successfully tested a new hot-water drill that they will use to access a subglacial lake for clean microbiological sampling and glaciological measurements. This interdisciplinary project is set to explore a portion of a vast hydrological system that exists under the Antarctic ice.

The WISSARD team includes nearly 20 researchers and is divided into three scientific components: microbiology, led by John Priscu, of Montana State University; geology, led by Ross Powell, of Northern Illinois University; and glaciology, led by Slawek Tulaczyk, of the University of California, Santa Cruz.

The team announced earlier this week that a test hole was drilled through the Ross Ice Shelf, a geographical feature the size of the state of Texas, into the seawater cavity below, which is over 900 meters (3000 feet) deep.

Once testing of the hot-water drill and the integrated filtration systems is completed on the ice shelf, all of the drilling equipment--including the drill, specialized filters and electrical generating equipment--will be moved, by means of an over-ice traverse, to the actual research drill site overlying Subglacial Lake Whillans.

Over the last several decades, ground-penetrating radar and other remote-sensing have revealed a vast system of rivers and lakes beneath the miles-thick Antarctic ice sheets. Geothermal heat from below, coupled with the pressure of the ice from above and the insulation provided by the ice sheet, cause some areas at the base of the ice sheet to remain above the freezing point, even in the extreme cold of Antarctica.

In order to explore one of these hydrological systems at the edge of the West Antarctic Ice Sheet on the southeastern edge of the Ross Sea, WISSARD proposes to use a variety of tools and techniques to explore this unique subglacial environment.

WISSARD will lower a variety of sampling tools and sensors into the Subglacial Lake Whillans. These tools will cleanly sample subglacial lake water and sediments, provide video of lake bottom, and characterize chemical and physical properties of the lake and its environs.

The custom-built WISSARD hot-water drill, developed at University of Nebraska - Lincoln under the leadership of Frank Rack, is designed to melt a 30-centimeter (11-inch) hole through 800 meters (2,600 feet) of ice at the actual research site, providing clean access to Subglacial Lake Whillans.

A variety of sophisticated tools will be sent down the borehole to collect data and samples, supported by equipment and laboratories on the surface. All are designed not to contaminate this previously unexplored environment and to maintain the pristine nature of this part of Antarctica.

WAIS

Researchers with the WAIS Divide project, meanwhile, have announced that an innovative technique, called Replicate Coring, will allow them to retrieve additional ice cores from specific depths in an existing borehole, a development that researcher Charles Bentley, at the NSF-funded Ice Drilling Design and Operations (IDDO) group at the University of Wisconsin said opens "a new door for the future of ice-core drilling."

The replicate drilling technique is a key advance, because it allows scientists to take samples from specific levels of a main borehole without impeding the hole itself, leaving the main borehole open for future logging of information. Previously, it would have been necessary to physically block off the main borehole to sample along the sides.

NSF supports innovations in ice-core drilling through a cooperative partnership between the Ice Drilling Program Office (IDPO) led by Dartmouth College, in collaboration with the University of New Hampshire and IDDO.

The Replicate Coring technique, which was developed and tested by the IDDO engineers as part of the DISC drill, was put into service at WAIS Divide during the 2007-2008 Antarctic field season. The design of the DISC Drill was started by the Wisconsin group in 2002 in response to the desire of the U.S. researchers for a deep-coring drill that would incorporate the ability to retrieve additional cores from the sides of the main borehole. The DISC drill completed the main WAIS borehole during the 2011-2012 season, reaching a depth of 3,405 meters (more than 11,000 feet). Testing of the replicate coring system at WAIS began at the end of the 2011-2012 season.

Unlike the drilling at PIG and WISSARD, the drilling at WAIS is designed to obtain cores of ice. These cores, or cylinders of ice, contain, frozen within them, samples of gases from the atmosphere as it was, in some cases, hundreds of thousands of years ago.

Previously, ice cores have yielded unexpected scientific discoveries, including, for example, evidence that climate can change abruptly in less than ten years, far less time than previously suspected. Analysis of ice cores also indicates that the level of carbon dioxide, a greenhouse gas, in the atmosphere is presently higher than in the past 800,000 years.

At the WAIS Divide site--an extremely cold area of the West Antarctic Ice Sheet, where the abundant snowfall rarely melts--the ice contains many tens of thousands of years of annual information about past climate. The cores obtained by replicate drilling will allow researchers to obtain samples from specific depths in the ice sheet, including from times of past abrupt climate change, allowing them to better understand how and why abrupt changes occur.

ANTARTIC ICE SHEET WARMING FASTER IN THE WEST



Map:  Antartica.  Credit:  CIA World Factbook.

FROM: NATIONAL SCIENCE FOUNDATION

Study Finds That Portions of the West Antarctic Ice Sheet Are Warming Twice as Fast as Previously Thought
Findings could have important implications for global sea-level rise
December 24, 2012
A new study funded by the National Science Foundation (NSF) finds that the western part of the massive West Antarctic Ice Sheet (WAIS) is experiencing nearly twice as much warming as previously thought.

The findings were published online this week in the journal Nature Geoscience. NSF manages the U.S. Antarctic Program (USAP) and coordinates all U.S. research and associated logistics on the southernmost continent and in the surrounding Southern Ocean.

The temperature record from Byrd Station, an unmanned scientific outpost in the center of the ice sheet, demonstrates a marked increase of 4.3 degrees Fahrenheit (2.4 degrees Celsius) in average annual temperature since 1958. That is three times faster than the average temperature rise around the globe.

This temperature increase is nearly double what previous research has suggested, and reveals--for the first time--warming trends during the summer months of the Southern Hemisphere (December through February), said David Bromwich, professor of geography at Ohio State University and senior research scientist at the Byrd Polar Research Center.

"Our record suggests that continued summer warming in West Antarctica could upset the surface mass balance of the ice sheet, so that the region could make an even bigger contribution to sea-level rise than it already does," said Bromwich.

"Even without generating significant mass loss directly, surface melting on the WAIS could contribute to sea level indirectly, by weakening the West Antarctic ice shelves that restrain the region's natural ice flow into the ocean."

Andrew Monaghan, study co-author and scientist at the National Center for Atmospheric Research (NCAR), said that these findings place West Antarctica among the fastest-warming regions on Earth.

"We've already seen enhanced surface melting contribute to the breakup of the Antarctic's Larsen B Ice Shelf, where glaciers at the edge discharged massive sections of ice into the ocean that contributed to sea level rise," Monaghan said. "The stakes would be much higher if a similar event occurred to an ice shelf restraining one of the enormous WAIS glaciers."

Researchers consider the WAIS especially sensitive to climate change, explained Ohio State University doctoral student Julien Nicolas. Since the base of the ice sheet rests below sea level, it is vulnerable to direct contact with warm ocean water. Its melting currently contributes 0.3 mm to sea level rise each year--second to Greenland, whose contribution to sea-level rise has been estimated as high as 0.7 mm per year.

Due to its location some 700 miles from the South Pole and near the center of the WAIS, Byrd Station is an important indicator of climate change throughout the region.

In the past, researchers haven't been able to make much use of the Byrd Station measurements, due to the fact that since the station was establishment in 1957, it hasn't always been occupied. So, its data were incomplete, to the point that nearly one third of the temperature observations were missing for the time period of the study. A year-round automated station was installed in 1980, but it has experienced frequent power outages, especially during the long polar night, when its solar panels can't recharge.

Bromwich and two of his graduate students, along with colleagues from the National Center for Atmospheric Research and the University of Wisconsin-Madison, corrected the past Byrd temperature measurements and used corrected data from a computer atmospheric model and a numerical analysis method to fill in the missing observations.

Aside from offering a more complete picture of warming in West Antarctica, the study suggests that if this warming trend continues, melting will become more extensive in the region in the future, Bromwich said.

While the researchers work to fully understand the cause of the summer warming at Byrd Station, the next step is clear, he added.

"West Antarctica is one of the most rapidly changing regions on Earth, but it is also one of the least known," he said. "Our study underscores the need for a reliable network of meteorological observations throughout West Antarctica, so that we can know what is happening--and why--with more certainty."

ANTARTIC CAMPSITE FOUND THAT MAY HAVE BEEN USED BY FAMOUS 1912 EXPEDITION

 

Captain Robert Falcon Scott, leader of the Terra-Nova-Expedition ,1911-1913, in polar gear. From: Wikimedia Commons.

FROM:  NATIONAL SCIENCE FOUNDATION

December 13, 2012

 A National Science Foundation-funded research team working on the slopes of the world’s southernmost active volcano appears to have found the remains of a camp used by explorers of the so-called "Heroic Age" of Antarctic exploration, a century after the camp was abandoned.

Although photos of the site, known as "the highest camp", appear to match an archival photograph taken by members of the 1912 Terra Nova expedition led by Royal Navy Captain Robert F. Scott, conservators from the New Zealand-based Antarctic Heritage Trust have been asked to verify the historic find.

The find comes in the closing days of the centennial of the so-called "Race to the Pole" between Scott and Norwegian Roald Amundsen. Amundsen reached the geographic South Pole on Dec. 14, 1911, five weeks before Scott’s party. In the tragic finish to the race, Scott and his men perished on the ice on their return trip, only a few miles from safety.

A ring of stones, where a tent once stood in what may have been a Terra Nova campsite, was discovered by Clive Oppenheimer, a volcanologist at Cambridge University in the United Kingdom. Oppenheimer is working on Mt. Erebus, a 14,500-foot, ice-covered volcano, as part of a team of NSF supported researchers led by Phillip Kyle of the New Mexico Institute of Mining and Technology.

With support from NSF, Kyle has been studying Mt. Erebus for decades. The volcano is unique in the world, not only because of its location, but also because of other features, notably a lake of lava deep in the ice-covered crater.

Oppenheimer is the first known visitor to the site since Scott's men left. He found it using a combination of written accounts and historic images from the Scott Polar Research Institute in Great Britain, which was founded by one of the party that climbed the volcano in 1912.

Although Oppenheimer is working on Erebus as a member of a team supported by the U.S. Antarctic Program, which is managed by NSF, he found the site during a break in the research work.

NSF is taking steps, along with international partners New Zealand and the U.K., to insure that the archeological value of the site is maintained.

A survey will record the area and search for items that may have been left behind in 1912.

A number of the Heroic Age huts used by explorers such as Scott and Sir Ernest Shackleton in the early years of the 20th century, have similarly been preserved and contain a wide range of artifacts--from scientific equipment to expedition supplies--that have been extraordinarily well preserved by the extremely cold and dry Antarctic climate

Records show that a camp was erected in 1912 by a team from the shore party of the Terra Nova Expedition that climbed Mt. Erebus. This was the second group to examine the summit region of Mt Erebus. A group from Shackleton’s Nimrod Expedition (1907-1909), including famed Australian geologist Sir Douglas Mawson, was the first to climb Erebus and observe the active lava lake in 1908.

The team that camped at this site was led by geologist Raymond Priestley and included Tryggve Gran, a Norwegian ski specialist; Frederick Hooper, formerly a steward on the Terra Nova; Royal Navy Able Seaman Harry Dickason; Petty Officer George Abbott and geologist Frank Debenham. They undertook mapping and collected geological specimens.

It was during his time on Mt. Erebus that geologist Frank Debenham had the idea of a "Polar Research Institute." After serving in World War I, Debenham was named the founding director of the University of Cambridge's Scott Polar Research Institute.

Philippe Foster Back, granddaughter of Frank Debenham and chair of the United Kingdom Antarctic Heritage Trust, said "Clive Oppenheimer's location of the original 'highest camp' is a wonderful addition to all the activity which has taken place throughout 2012 to mark the centenary of Captain Scott's expedition. It is a reminder of both the dangers and thrills of Antarctic science and a fitting tribute to the great legacies of exploration and discovery left to us by all the brave men of that party."

Atop an Antarctic Volcano, NSF-funded Researcher Finds Camp Site from the "Heroic Age" of Antarctic Exploration

NEAR TERM EXTINCTION OF AMAZON TREE SPECIES UNLIKELY TO BE CAUSED BY CLIMATE WARMING

Phoito:  Tropical Forest Brazil.  Credit:  Wikimedia Commons.

FROM: NATIONAL SCIENCE FOUNDATION

Climate Warming Unlikely to Cause Near-Term Extinction of Amazon Tree Species
December 13, 2012
New genetic analyses show that some common Amazon tree species are more than 8 million years old.

The analysis also reveals that these surprisingly old species have endured past periods of significant climate warming. It therefore appears unlikely that human-caused temperature increases alone will cause mass extinctions of the trees in the coming century.

Results of a study by evolutionary biologist Christopher Dick of the University of Michigan and colleagues show that some trees in the Amazon rainforest have survived warm periods similar to the global warming scenarios forecast for the year 2100.

"In the absence of other major environmental changes, near-term high-temperature-induced mass species extinction is unlikely" in the Amazon forest, Dick and colleagues conclude in a paper published online today in the journal Ecology and Evolution.

"The rapidly changing climate of our planet has the potential to put great stresses on plants and animals," said Sam Scheiner, program director in the National Science Foundation's (NSF) Division of Environmental Biology, which funded the research.

"To prepare for these changes, we need to know how species have adapted to past climate change," Scheiner said. "Much more is left to be learned about the effects of climate change."

The new results are at odds with earlier findings based on ecological niche-modeling scenarios that predict tree species extinctions in response to relatively small increases in global average air temperatures.

Dick used a molecular clock approach to determine the ages of 12 widespread Amazon tree species.

Then he and other scientists looked at climate events that have occurred since those tree species emerged. In general, the older the tree species, the warmer the climate it has previously survived.

The researchers determined that nine of the tree species have been around for at least 2.6 million years, seven have been present for at least 5.6 million years and three have existed in the Amazon for more than eight million years.

"These are surprisingly old ages," Dick said. "Previous studies have suggested that a majority of Amazon tree species may have originated during the Quaternary Period, from 2.6 million years ago to the present."

"The most lasting finding of our study may be the discovery of ancient geographic variation within widespread species, indicating that many rainforest tree species were widely distributed before the major uplift of the northern Andes," said paper co-author Eldredge Bermingham of the Smithsonian Tropical Research Institute.

Air temperatures across Amazonia in the early Pliocene Epoch--3.6 million to 5 million years ago--were similar to Intergovernmental Panel on Climate Change (IPCC) projections for the region in 2100 using moderate carbon-emission scenarios.

Air temperatures 5.3 to 11.5 million years ago in the late Miocene Epoch were about the same as IPCC projections for the region in 2100 using the highest carbon-emission scenarios.

"Our results provide evidence that common Neotropical tree species endured climates warmer than the present, implying they can tolerate near-term future warming under climate change," said Dick.

Paper co-author Simon Lewis of University College London and the University of Leeds cautioned that the good news for Amazon trees is not a panacea.

"The past cannot be compared directly with the future," he said.

"While tree species seem likely to tolerate higher air temperatures than today, the Amazon forest is being converted for agriculture and mining, and what remains is being fragmented by roads and fields.

"Species will not move as freely in the Amazon as they did in previous warm periods, when there was no human influence. Today's climate change is extremely fast, making comparisons with the past difficult."

The 12 tree species used in the study are broadly representative of the Amazon tree flora.

Primary forest collection sites were in central Panama, western Ecuador and Amazonian Ecuador. Additional collections were in Brazil, Peru, French Guiana and Bolivia.

Other plant samples were obtained from herbarium specimens.

To determine the age of each tree species, the researchers extracted and sequenced DNA from plant samples, then looked at the number of genetic mutations contained in those sequences.

Using a molecular clock approach and population genetic models, they estimated how long it would take for each of the tree populations to accumulate the observed number of mutations, which provided a minimum age for each species.

Tropical rainforests have existed in South America for at least 55 million years.

The future of the contemporary Amazon forest is uncertain, however, as the region is entering conditions with no past analog, combining rapidly increasing air temperatures, high atmospheric carbon dioxide concentrations, possible extreme droughts and extensive removal and modification of the forest by humans.

The findings imply that droughts, direct human effects and their interactions "may be more immediate threats to the integrity of Amazon rainforests, and should remain a focus of conservation policy," the authors conclude.

"An important caveat is that because we've been in a cold period over the past 2 million years--basically the whole Quaternary Period--some of the trees' adaptations to warmth tolerance may have been lost," Dick said.

In addition to Dick, Bermingham and Lewis, Mark Maslin of University College London is a co-author of the paper.

Additional support for the research was provided by the Smithsonian Tropical Research Institute, the University of Michigan and the Royal Society.