Ice, Ice, Baby!

August 28, 2009

Over a mile of ice core taken at the NEEM camp, which sets a new drilling record.

Cores taken from deep in the ice sheet are under enormous pressure. When brought to the surface where pressure is much less, they can shatter. To avoid this, deep ice cores are stored in a buffer to 'relax' before they are moved. NEEM cores may rest in the buffer for up to a year before being moved. Photo: Sune Olander Rasmussen. NEEM ice core drilling project, www.neem.ku.dk.

Cores taken from deep in the ice sheet are under enormous pressure. When brought to the surface where pressure is lower, they can shatter. To avoid this, deep ice cores are stored in a buffer to 'relax' before they are moved. NEEM cores may rest in the buffer for up to a year. Photo: Sune Olander Rasmussen. NEEM ice core drilling project, http://www.neem.ku.dk.

Congratulations to chief scientist Dorthe Dahl-Jensen (University of Copenhagen) and the international NEEM team on a dream season!

Read the National Science Foundation press release.


Glacier Quakes

August 18, 2009

Meredith Nettles of Lamont-Doherty Earth Observatory, a scientist studying glacier dynamics in Greenland, sent a link to her project Web site the other day. There, in addition to basic information on her NSF-funded study, you can find a few pictures from the first of two field trips this year and a sheaf of photos from previous years as well.

The team accesses its monitoring sites via helicopter, landing on the scarred surface of the glacier. Source: Nettles Web site

The team accesses its monitoring sites via helicopter, landing on the scarred surface of a southern Greenland glacier. Source: Nettles Web site

Nettles and colleagues Gordon Hamilton (University of Maine) and Jim Davis (Smithsonian), along with Danish and Spanish colleagues and technical experts from UNAVCO, have placed Global Positioning Systems (GPS) networks on two of Greenland’s most active outlet glaciers, Helheim and Kangerdlugssuaq, both on the island’s southeastern coast.  These glaciers dump massive quantities of fresh water into the Arctic Ocean, and back around 2005 scientists noticed that they (and other glaciers in Greenland’s south) seemed to be flowing a lot faster all at once:  a statue placed on Helheim Glacier in January 2002 would have advanced an impressive six kilometers toward the ocean by year’s end; but during 2005 the same statue would have raced seaward some 11 kilometers—about half a football field a day, Gordon Hamilton estimated.  In addition to accelerated advance, the science team observed that the glacier—about 700 meters (nearly half a mile) thick from muddy bottom to tumbled top, seemed to be thinning rapidly as well, which suggested further destabilization.

The calving front of Helheim Glacier, 2006. Photo: Meredith Nettles

The calving front of Helheim Glacier, 2006. Photo: Meredith Nettles

The seasonal processes driving these changes are what the Nettles collaboration is attempting to discover. For the past few years, researchers have gone to one or both of the glaciers and placed GPS instruments on the ice to create the monitoring networks. (On the Helheim, the team has also placed time-lapse cameras and instruments to monitor climate, seismic and tidal activity.)  These have then collected precise information about the glaciers’ movements, sending data via radio signal to a collecting station on a rock outcrop which in turn sends data back to the Nettles lab via Iridium phone.

Here researchers install a GPS instrument in the middle of nowhere--actually a northern section of the Helheim). Photo: J. Vilendal Petersen

Here researchers install a GPS instrument in the middle of nowhere--a northern section of the Helheim). Photo: J. Vilendal Petersen

The networks have captured information about so-called glacier quakes, phenomena discovered less than a decade ago by Nettles and colleagues monitoring other seismic information. The team noticed that seismic signals were being recorded in clusters around the coast of southern Greenland, an area traditionally associated with little seismic activity. Further study revealed that the seismic activity was caused by sudden, fierce movement of glaciers lurching forward, but the physical processes where not known.

Since then, Nettles and others have learned a bit about these quakes. Nettles talked with Popular Mechanics earlier this year, explaining how glacier quakes work:

“We saw a couple last summer from our helicopter, near the calving front. We were at the outlet to the Helheim glacier, in a system of fjords with sheer rock walls that are 500 meters [more than 1600 ft] tall. Typically, you start to see a rift open up in the glacier and then this big block of ice starts to roll over. The block that breaks off might be a couple of kilometers long and it’s the full thickness of the glacier, which is about seven hundred meters—mainly underwater. . . . It takes a couple of minutes to fall, and as it’s rolling, it has to move this thick melange of ice and water that’s in front of it out of the way. You start to see the icebergs moving very, very fast down the fjord or, if they’re close to the calving front, you see them being popped up, straight towards the helicopter. Then you see just tons of water streaming off of the new iceberg as it is being formed. We have instruments to detect the resulting tsunami about 35 or 40 kilometers away.”

Not for the faint of heart.

Instruments located on Helheim Glacier, Greenland.

Instruments located on Helheim Glacier, Greenland.

After capturing a season’s worth of data on the GPS networks, the Nettles team is back in the field this week removing the Kangerdlugssuaq network and winterizing that on the Helheims. She indicated that she is pleased with the data capture. See for yourself by clicking “Telemetry Status” on the project Web page.


That Dam Glacier

August 11, 2009

There are a few once-in-a-lifetime natural events some of us are lucky to witness—like the sighting of the Hale-Bopp comet, or the longest solar eclipse of the century. Most awe-inspiring natural events, though, occur in remote obscurity, remaining unknown to all but the few people who study them and usually discover them after the fact.

And then there’s southeastern Alaska’s Hubbard Glacier, the fastest-moving, largest tidewater glacier in North America. The glacier is on the verge of damming adjacent Russell Fjord at Gilbert Point. When the glacier seals the entrance it will create a 64-kilometer lake, a natural event that has rarely been observed as it happens.

The rapidly advancing Hubbard Glacier. Source: U.S. Forest Service

The rapidly advancing Hubbard Glacier. Source: U.S. Forest Service

Daniel Lawson of the Cold Regions Research and Engineering Laboratory will be there to document it thanks to a recent National Science Foundation grant.  He and several field researchers will visit the glacier to collect a variety of information about the lead up, the damming event itself, and its aftermath. They will use remote sensing information and a suite of sensors placed on the glacier surface to gather their data. The team will also visit observation points via helicopter or boat and will take several fixed-wing over-flights for aerial photography.

It's easy to see why the glacier is a cruise-ship favorite. Photo: Richard Wainscoat, http://www.wainscoat.com

It's easy to see why the glacier is a cruise-ship favorite. Photo: Richard Wainscoat, http://www.wainscoat.com

Completely closing Russell Fjord could devastate the salmon fisheries in the adjacent Situk River, an economic lifeblood for the city of Yakutat. According to a 2007 Forest Service report, closing the Hubbard-Russell ice dam will increase the river’s daily flows from 3 to 11 cubic meters per second (cms) to more than 566 cms if the lake flows over the glacial moraine. In addition to its prolific salmon fishery, the river draws myriad tourists to the region each year.

Located near Yakutat, the Hubbard Glacier encompasses an area of ~3900 square km, flowing 120 kilometers from the flanks of Mt. Logan (5959 meters and located in the Wrangell – St. Elias Mountains) to sea level, where its terminus widens to over 13 kilometers across the head of Disenchantment Bay and the entrance to Russell Fjord.

hubbard_glacier_map_locaterUnlike most southeastern Alaskan glaciers, Hubbard is thickening and advancing, most recently at an average rate of 35 meters per year for the last 15-16 years. The high accumulation area ratio (0.95) of Hubbard Glacier suggests that it will continue to advance for a hundred years or more, barring any significant changes in climate raising its Equilibrium Line Altitude (ELA) by nearly 1000 meters.


In the NEEM Tunnels

July 13, 2009

The process of taking several kilometers of core out of the middle of a great ice sheet is a gigantic undertaking. There’s the frosty landscape, barren of infrastructure and the seemingly interminable logistics chain, both of which drive the stakes high and require a lot of commitment.  And then there’s the fragile treasure—the ice itself, worth its weight in gold by the time it sees daylight given the cost of its capture.

"The main NEEM building, the dome, is just beautiful inside," Robbie Score commented. There's a lot of ambient light, comfortable furniture, well-organized space." Robbie managed to take a quick tour of the dome after touring the ice coring facilities under ground.

"The main NEEM building, the dome, is just beautiful inside," Robbie Score commented. There's a lot of ambient light, comfortable furniture, well-organized space." Robbie managed to take a quick tour of the dome after touring the ice coring facilities under ground.

CPS staffers Robbie Score and Ed Stockard visited the NEEM drilling camp recently with a group of media, and were treated to a tour of the ice coring and processing facilities located below ground. “It almost felt like a science fiction experience,” Robbie recalled. “We were six meters underground, surrounded by all this activity. The international flavor of it added to the energy—there were people from Korea, Denmark, Germany, the US and other places, all working on various elements of the project.” Robbie says that the coring team has to pipe surface air down into the underground rooms to offset the heat from so many bodies, instruments, machines, and computers at work.

This is the drilling station. The tower apparatus in the center of the room is the drill rig. The spool, front center, holds the cable on which the drill itself travels up and down the casing. The NEEM drill, newly engineered, is working gorgeously, and the researchers are also delighted with the new, plant-derived fluid used to keep the hole from freezing.

This is the drilling station. The tower apparatus in the center of the room is the drill rig. The spool, front center, holds the cable on which the drill itself travels up and down the casing. The NEEM drill, newly engineered, is working gorgeously, and the researchers are also delighted with a biodegradable, plant-derived fluid used to keep the hole from freezing or collapsing.

Per the NEEM Web site, the drill can hold about four meters of core, and each run takes somewhere between 40 minutes and several hours, depending on how deep the drill has to descend to reach ice. The NEEM team will need to make about 800 runs to reach the muddy bottom 2.5 km below the surface, so spring/summer drilling operations will continue at least into late 2010.

Ed Stockard got this shot of ice core coming out of the drill barrel.

Ed Stockard got this shot of ice core coming out of the drill barrel.

When it is brought up, the core is taken to a second underground room connected to the drilling area itself by a subterranean tunnel:

There is so much activity that the drilling room is separated from the processing room by a long tunnel.

There is so much activity that the drilling room is separated from the processing room by this long tunnel.

About half of the core is stabilized, packed, archived, and stored for shipment to ice core storage facilities. The rest is analyzed over in the NEEM tunnel, subjected to a series of increasingly destructive measurements: The core is first polished to create the smooth surface needed for some of the optical measurements; the process continues with conductivity tests, which can point to material in the core that provides evidence of big events like volcanoes; after several more tests,  the core is melted for isotopic analysis.

In the science room: Some of the core runs a gamut of tests in the science room, giving up its secrets to scientists without ever leaving Greenland.

Some of the core runs a gamut of tests in the science room, giving up its secrets to scientists without ever leaving Greenland.

On-site processing saves some of the huge logistics costs involved in shipping the core, and it also provides insurance against the risk of catastrophic failure during core transport. Given the planning and effort this frozen treasure demands of the NEEM team, a little insurance is a very good thing.

Pictures by Robbie Score unless otherwise identified.


Postcards from Toolik

June 25, 2009
Emily Stone is a Chicago-based freelance writer. She’s on a 16-day science journalism fellowship at Toolik Lake through the Marine Biological Lab (MBL).
This is the small stream that leads into the Toolik River that formed a thermokarst several years ago. The green on the left side is actually the stream, which looks more like a marsh. Just below that, the stream opens up into a muddy canyon where the ground falls away in the thermokarst.

This is the small stream leading into the Toolik River that formed a thermokarst several years ago. The green on the left side is actually the stream, which looks more like a marsh. Just below that, the stream opens up into a muddy canyon where the ground falls away in the thermokarst.

The trick with having a surface that sits on ice – which is what permafrost tundra is – is that if that ice melts, the ground falls away.

That’s what’s happening across the arctic in a phenomenon known as thermokarst. The underground ice melts, the water rushes away and the ground collapses into a sinkhole. That’s bad news for any buildings or roads that straddle a thermokarst. Now scientists are starting to study what it means for the ecosystems around the holes.

With a grant from the National Science Foundation, Breck Bowden of UVM is leading a team of 25 researchers studying the impact of thermokarsts around Toolik on everything from nearby rivers and streams, the microbes in the soil, the vegetation and the atmosphere. The group arrived on station and started their work in late June.

In a previous study, Bowden looked at old aerial photos of the area around Toolik from the mid-80s and compared them to satellite photos from 2006. He found twice as many thermokarst depressions in 2006 than 20 years earlier.

The journalist fellows visited a thermokarst this week on a stream that feeds into the Toolik River. Above the thermokarst, the stream looked like a marsh as the water ran through tall, bright green grass. At the thermokarst, the stream suddenly opened up into a large, muddy chasm clear of plants. It was obvious that an enormous amount of soil had fallen into the stream. Researchers are interested in what that soil is doing to the water in the stream and in the Toolik River just below it.

We took water samples and started running tests on them to see what the difference in nutrient levels was above and below the thermokarst. We’ve just started analyzing the data, but it looks like a significant amount of the nitrate in the Toolik River is coming from the thermokarst. More nutrients like nitrates likely mean increased algae and moss, which can quickly change the composition of the insects and fish in the river.


Visiting NEEM

June 25, 2009

Through Ed Stockard’s Viewfinder

Ed recently visited the deep ice core drilling camp, NEEM, out on the Greenland ice sheet, flying there with a group of media invited by the Air National Guard. Take a look.

Here the journalists are transported on snowmobile-towed sleds from the skiway and the LC-130 that has flown them to NEEM.

Here the journalists are transported on snowmobile-towed sleds from the skiway and the LC-130 that has flown them to NEEM.

The group toured the ice coring facility, two underground rooms with a tunnel between them.
This is the drilling trench. Despite the room's snow walls, temperatures were getting a bit too warm for the ice core. The NEEM team has installed air intake systems to help combat the heat.

This is the drilling trench. Despite the room's snow walls, temperatures were getting a bit too warm for the ice core. The NEEM team has installed air intake systems to help combat the heat. More on the actual drilling operation to come.

Three stories high, filled with comfortable furniture and ambient light (sometimes a little too much ambient light, per the NEEM Web site!), the NEEM dome houses the dining facility, lounging areas and computer work stations, even a few bunk beds for nappers. The top floor aerie is the home of the NEEM camp leader, who makes weather observations and communicates with the outside world while keeping an eye on the place from the perch.
Robbie Score also visited NEEM. Her general impression of the place is evident on her face.

Robbie Score waits for a bus in front of the NEEM dome. Her thoughts on the place in a future posting.

Inside the dome, the kitchen is a warm haven. A talented chef is an object of great affection at a field camp like NEEM, as Sarah Harvey, pictured below in the NEEM kitchen, can tell you.
If you're thinking the NEEM team eats dehydrated food warmed over a well-used portable stove, think again.

If you're thinking the NEEM team eats dehydrated food warmed over a well-used portable stove, think again.


Chasin’ Jason (Box)

June 22, 2009
Jason Box uses photogrammetry in some of his research. Lucky for us. Photo from Box BPRC Wiki site.

Jason Box uses photogrammetry in some of his research. Lucky for us. Photo from the Jason Box BPRC Wiki site.

Don’t blink if you want to keep track of Jason Box. The research scientist and geology professor at the Byrd Polar Research Center (The Ohio State U) is busier than a dog in a bone factory this summer in Greenland. He’s working on a NASA-funded project involving time-lapse photography of some of Greenland’s fastest moving glaciers, providing scientific expertise aboard a Greenpeace cruise attempting to document the predicted further collapse of Petermann Glacier, and embarking on an oceanography/glaciology sailing adventure to look at Greenland’s ocean-terminating glaciers, the latter aboard the 48-foot steel ketch, the Gambo.

According to Box’ blog, Meltfactor, there are subprojects as well, but we figure the foregoing is a good glimpse of the man’s packed agenda. To get a sense of why the work Box does is important, visit the Extreme Ice Survey Web site, where some of Box’ time-lapse photography is spectacularly featured.

JBoxLeavingUunmmannaq

Some of the sites where Jason Box places his glacier-monitoring time-lapse cameras are so remote he has to access them via boat. View this and other Box photos on his Byrd Polar Research Wiki site.

Box arrived on this second Greenland trip of the summer season using the National Science Foundation’s logistics C-130 chain from New York to Kangerlussuaq. After organizing cargo for August work on the NASA project, which CPS supports, he ventured off on other projects. About now he should be on the Greenpeace vessel for the cruise to document Petermann Glacier’s potentially spectacular calving front.

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Petermann Glacier rift, September 7, 2008. For detailed information on these images, click here. Credit: Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

Box is updating his blog, so tune in there for updates on his whereabouts.


Don’t Bring Me Down

June 1, 2009

GNET measures Earth bouncing back

By Marcy Davis

DSC_1541

Abel Brown (The Ohio State University) awaiting a helicopter pick up at Hjornefjedet on Greenland's east coast. Photo: Dana Caccamise, OSU

During the last ice age, ice sheets up to three kilometers thick covered the areas of northern Europe, Asia, and North America. The enormous weight of the ice down-warped the land surface, causing the material underlying these land masses to slowly flow away. The physics are similar to the reasons a balloon deforms when you press down on it. In the same way that the balloon reshapes itself when you remove your hand, the land actually pops back up over several thousand years when the weight of expansive ice sheets no longer weighs down the underlying area. In Greenland, where the ice sheet is currently receding, the island is actively rebounding.

And members of the GNET team are watching it happen.

Read the rest of this entry »


Summit Station Science

May 28, 2009

Recent visitors to Summit Station include Harro Meijer’s team from the Netherlands, which spent a whirlwind few days on station taking shallow ice cores from a specially prepared snow field. Meijer is studying isotope diffusion in ice cores; his results will help experts better interpret information from ice cores being studied to reconstruct climate history.

The Meijer team harvested shallow ice cores to about two meters depth from an isotopically enriched site (seen here within the flag border) near Summit Station. They also conducted maintenance on dataloggers at the site.

The Meijer team harvested shallow ice cores to about two meters depth from an isotopically enriched site (seen here within the flag border) near Summit Station. They also conducted maintenance on dataloggers at the site.

Later, researchers processed the cores, slicing them into 1-2 cm-thick layers and packing them in plastic bags for shipment back to the Netherlands.

The Meijer team processed cores in Summit's below-ground freezer. Photos courtesy Gerko van der Wel, University of Groningen

The Meijer team processed cores in Summit's below-ground freezer. Photos courtesy Gerko van der Wel, University of Groningen