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.


In the Media

August 14, 2009

 

The map of sea level pressure (in millibars) from July 1 to 31, 2009, shows a strong high-pressure cell over the Beaufort Sea. In 2007, a similar high-pressure cell, combined with unusually low pressure over eastern Siberia, contributed to the record melt. Source: NSIDC

The map of sea level pressure (in millibars) from July 1 to 31, 2009, shows a strong high-pressure cell over the Beaufort Sea. In 2007, a similar high-pressure cell, combined with unusually low pressure over eastern Siberia, contributed to the record melt. Source: NSIDC

A strong high-pressure system bringing abundant sunshine in July helped to shrink arctic sea-ice extent at roughly the same rate as was seen in 2007, says the National Snow and Ice Data Center in its latest news release.

Visit polar bears in Kaktovik, Alaska, with Richard Nelson (whose one-man show on Alaska Public Radio, Encounters,  receives NSF funding). This Men’s Journal article will take you there.

For a Canadian perspective on the joint CCGS Louis S. St-Laurent and USCGC Healy mapping expedition, read a series of reports by Pulitzer Prize-winning journalist Paul Watson, who is aboard the Louis.

Ned Rozell is going to ‘Monster Island’ next week!  Details in his latest Alaska Science Forum piece.

That 13-mile-long, hairy, gelatinous, black goo found floating by subsistence hunters in the Arctic Ocean off Alaska’s North Slope earlier this summer? An oil slick? No. A monster? No. An algae bloom.


Bridge your Science to the Public with a PolarTREC Teacher!

August 13, 2009
By Kristin Timm
Despite language differences, PolarTREC Teacher Tim Martin works with an international research team at Lake El’gygytgyn in Northeast Siberia. All photos courtesy ARCUS

Despite language differences, PolarTREC Teacher Tim Martin works with an international research team at Lake El’gygytgyn in Northeast Siberia. All photos courtesy ARCUS

PolarTREC – Teachers and Researchers Exploring and Collaborating, a project of the Arctic Research Consortium of the U.S. funded by the National Science Foundation – matches K-12 teachers with polar researchers to participate in polar research, as a pathway to improve science education. The program integrates research and education to produce long-term teacher-researcher collaborations, improved teacher content knowledge and instructional practices, and broad public interest and engagement in polar science.

Through PolarTREC, primarily K-12 teachers spend two to six weeks in the Arctic or Antarctic, working as an active and integral part of the science team. While in the field, teachers and researchers communicate extensively with students across the globe, using a variety of tools including online journals, forums, and interactive webinars that often reach hundreds of students at a time. Researchers report that the outreach activities provided through PolarTREC help bridge their science and the public and makes broader impacts fun, rewarding, and easy.

PolarTREC Teacher, Tom Harten, a.k.a. the “Murre-minator,” prepares for another day’s work marking sea birds in the Pribilof Islands.

PolarTREC Teacher, Tom Harten, a.k.a. the “Murre-minator,” prepares for another day’s work marking sea birds in the Pribilof Islands.

“I have a much stronger belief in the work I do now that I know that there are people out there who value my work,” one researcher said after participating in PolarTREC. “The experience I gained in working with both PolarTREC and their top-notch teachers taught me how to communicate my research better and even how to more effectively plan my research program so that it can be embedded into larger interdisciplinary problems.” According to initial evaluation data, other PolarTREC researchers reflected similar satisfaction with their participation in the program. Many also added that both their research and the scientific process benefit from including a teacher on their team. The need to explain their research and “boil it down to the raw essence” helped the research teams see how their work fits into a “bigger world picture” and how they can present their science effectively to a broad audience.

PolarTREC Teacher Simone Welch works with researchers onboard the USCGC Healy slicing and preparing ice cores for analysis back in the lab.

PolarTREC Teacher Simone Welch works with researchers slicing and preparing ice cores for analysis back in the lab.

PolarTREC applicants (teachers and researchers) are thoroughly reviewed by a selection committee of their peers, and initial matches are based on similar science interests. Researchers selected to participate in PolarTREC receive about eight best match teacher applications, have the opportunity to interview three of them, and then make the final selection. Selected teachers participate in an intensive orientation and are trained extensively prior to the field season. Working with their researchers before the field season, teachers also acquire any needed equipment training, build their science knowledge, and get to know the team they will be working with. After the field season, teachers and researchers have sustained their relationships through co-presenting at scientific meetings and to schools and community groups, participating in data workshops, jointly creating classroom lesson plans, and writing proposals for future work together.

Working with a team of archaeologists and undergraduate students in Finland, PolarTREC Teacher Michael Wing clears vegetation at the Hiidenkangas Site.

Working with a team of archaeologists and undergraduate students in Finland, PolarTREC Teacher Michael Wing clears vegetation at the Hiidenkangas Site.

Apply Now!

PolarTREC is currently accepting applications from researchers for the fourth year of teacher research experiences. Researchers are invited to submit an application to host a PolarTREC teacher in the 2010 Arctic and/or the 2010/2011 Antarctic field seasons. More information and application forms are available at: http://www.polartrec.com.

Funding is pending for PolarTREC during the 2010 Arctic field season and the 2010-2011 Antarctic field season. ARCUS will keep researcher applicants informed of our funding status. If funding is secured, final matches should be made in December 2009 or January 2010.  

For More Information:

A one-hour informational webinar for researchers interested in hosting a PolarTREC teacher on their polar research project will be held on 18 August 2009 at 10:00 am ADT (8:00 am HST, 11:00 am PDT, 12:00 am MDT, 1:00 pm CDT, 2:00 pm EDT). Please register for the event at: http://www.polartrec.com/join/informational-webinar/form by 17 August 2009.

Questions? Please contact info@polartrec.com or call 907-474-1600.


Breaking the Ice

August 12, 2009
By Marcy Davis
The Canadian Coast Guard vessel Louis S. St-Laurent (front) and the US Coast Guard vessel Healy (back). Photo: Natural Resources Canada

The Canadian Coast Guard vessel Louis S. St-Laurent (front) and the US Coast Guard vessel Healy (back). Photo: Natural Resources Canada

Ice-breaking ships from Canada and the United States last week began a cruise to probe the Arctic Ocean in the continuation of a multi-year mission to survey—and possibly extend—each country’s maritime boundaries. The ships departed from Barrow, Alaska, and from Kugluktuk, Nunavut (northern Canada), and are collecting data to build highly detailed three-dimensional maps of the sea floor that may be used to revise maritime boundaries.

The shaded area on this map illustrates where the U.S. is considering collecting and analyzing data and does not represent the official U.S. Government position on where it has extended continental shelf. This map is without prejudice to boundary depictions and future negotiations. Credit: continentalshelf.gov

The shaded area on this map illustrates where the U.S. is considering collecting and analyzing data. It does not represent the official U.S. Government position on where it has extended continental shelf--or any other official position. It is for informational purposes only. Credit: continentalshelf.gov

Dr. Larry Mayer of University of New Hampshire, who is also the co-director of the Center for Coastal and Ocean Mapping, is the chief scientist aboard the U.S. Coast Guard Cutter Healy. His team will map the seafloor using a sophisticated instrument called a multibeam sonar. From the hull of the ship, the sonar emits over one hundred narrowly focused beams of sound to create a swath that travels outward from the ship. Receivers ‘listen’ for the echo of the sound waves as they bounce off the seafloor and reflect back to the ship. Then computers calculate the depth to the seafloor and create a map of the sea floor topography.

The US Coast Guard icebreaker Healy cuts through one of the least known areas of the world--the Arctic. Source: NOAA

The US Coast Guard icebreaker Healy cuts through one of the least known areas of the world--the Arctic. Source: NOAA

The Canadian Coast Guard Ship Louis S. St. Laurent will collect seismic data. Dr. David Mosher of the Geologic Survey of Canada will be the Canadian chief scientist.

The work is part of the Extended Continental Shelf Project, a joint effort to probe the Chukchi Borderland, an underwater promontory which extends north of Barrow, Alaska, into the Artic Ocean to near 80°N. The expedition aims to map the farthest reaches of the North American continent and determine the edge of the continental shelf, information that will be used as the countries ready their claims to extend their maritime boundaries past the current 200 nautical miles offshore mark, as allowed by the United Nations Convention on Law of the Sea. It is here that the U.S. stands to gain the most territory along with whatever natural resources it holds.

A country may use either constraint line to define the outer limits of its continental shelf: either 350 nautical miles seaward of the baseline, or 100 nautical miles seaward of the 2,500-meter depth contour (isobath).

A country may use either constraint line to define the outer limits of its continental shelf: either 350 nautical miles seaward of the baseline, or 100 nautical miles seaward of the 2,500-meter depth contour (isobath).

Of particular interest to the U.S. claim is the 2,500 meter isobath, the depth upon which many of the mathematical limits and formulae defined in the treaty rely. Mayer’s team also looks for a feature called ‘the foot of the slope,’ a major change in the shape of the sea floor which, according to the treaty, may mark the limit of the U.S. extended continental shelf.  He and his colleagues have mapped more than a million square kilometers of seafloor since 2003.

An aerial view of the Chukchi Borderland from the north, with tracks from 2003, 2004 and 2007 mapping expeditions.

An aerial view of the Chukchi Borderland from the north, with tracks from 2003, 2004 and 2007 mapping expeditions.

Many countries, including the U.S., will gain territory, although data analysis could take years. Once the United States senate officially accedes to the treaty, the U.S. will have ten years in which to turn over their data and formal claim to the U.N. Meanwhile, the Law of the Sea treaty protects the sea floor and underlying resources under stringent environmental laws.

Armchair sailors can monitor the cruise via several online sources, though transmission limitations in the Arctic Ocean may impact the number/frequency/size of these efforts.


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.


Dog Days of Summer

August 10, 2009
Toolik Field Station, Alaska, 9 August 2009
Photo: Mimi Fujino

Photo: Mimi Fujino


ANG Test Flights Propel Polar Airlift Potential

August 10, 2009
An LC-130 equipped with special 8-blade NP2000 propellers visits Summit Station, Greenland. Test flights such as this one suggest the 8-blade propellers will allow these cargo planes to take off on skis with much heavier cargo loads than do the standard 4-blade propellers. Photo: Mark Doll, USAF

An LC-130 equipped with special 8-blade NP2000 propellers visits Summit Station, Greenland, late in July. Test flights suggest the propellers will allow these cargo planes to take off on skis with much heavier cargo loads than do the standard 4-blade propellers. Photo: Mark Doll, USAF

We heard from Mark Doll today after he’d had a chance to catch up from “a great week in Greenland.”  That week, a flight period for the New York Air National Guard 109th Airlift Wing, included test flights of an eight-blade propeller system mounted on the LC-130 cargo planes, which provide the heavy airlift to the National Science Foundation’s polar research program.  

How did it go?

“In short, the NP2000-equipped LC-130 works great,” wrote Lt Col Doll (the Air Guard’s liaison to the National Science Foundation’s polar program).

“During the week of 27-31 July, the 109th continued test flights with the 8-blade NP2000 propeller. The program consisted of two trips to Summit and one to Raven Camp. At each place, we conducted a series of take-offs at various weights both on the skiways and in the open snow. While we are still reducing the data, we can say that we set an unofficial take-off record at Summit: 143,000 lbs, -11 deg C – with an 18kt tailwind! Granted the snow was quite good, and the skiway in great shape, but no one expected a successful take-off under those conditions. The whole crew was surprised. We even took off from Summit open snow at 113,000 lbs; under normal conditions, that would have been impossible even with JATO.

Ed Stockard shot this photo of Skier 92 coming in for a landing at Raven Camp. That building at rear was part of the Distant Early Warning array established across the arctic during the cold war.

Ed Stockard shot this photo of Skier 92 at Raven Camp. Dye 2, rear, was part of the Distant Early Warning System radar sites established across the Arctic during the cold war, and it is located about 1 mile from Raven.

“The NP2000 propeller offers reduced vibration, noise and maintenance costs, while increasing thrust. The absolute amount of increased thrust is still being determined. However, in our subjective opinion, it offers much better performance for ski take-offs. Our intent is to eventually equip all LC-130s with the NP2000 to increase our cargo-carrying capability while reducing the use of JATO.”

The planes, traditionally outfitted with four-blade propellers, have skis to land on snow and ice. And while these are absolutely essential at the poles where few paved runways exist, the LC-130s pay a high price in terms of efficiency: drag makes the “Ski Birds” ungainly on takeoff (and can lead to ski ways that are several miles long!) and it also reduces air speed.

A NP2000-equipped LC-130 flies over bergy waters. Photo: Mark Doll

An NP2000-equipped LC-130 flies over bergy waters. Photo: Mark Doll

The test flights cap about 10 years of research and development for Doll and colleagues, he says.  Back in 1999, “I started asking questions about the thrust of the existing propeller so I could start to define the ski drag,” Doll recalls. ”I quickly was referred to Hamilton Standard (Hamilton Sundstrand) for some answers. That started the relationship that led to the NP2000 discussions. At the time, the propeller was being designed for the Navy’s E-2 Hawkeye; the C-130 was only a dream.

“It has been a long road to get this far; and we’re still a long way from success. Even after we prove the viability and capability of the NP2000, we still have to procure the funds for installation. Last week in Greenland was a success and brought us one step closer to an answer, no matter what the answer is.”


For the Birds

August 6, 2009

Between a cornucopia of fish, throngs of insects, and the expansive algae “salad” proffered by the ocean, bird species in the Arctic are rarely at a loss for food. Add in killer wind patterns and a range of nesting sites—from cliffs to meadows—and migrating to the Arctic is quite appealing.

Where there are birds, there are researchers who take advantage of the around-the-clock northern light to study everything from ideal living conditions, to avian evolution and breeding strategies, and more. Plus they have the added bonus of conducting fieldwork in beautiful remote places. Here’s a sampling of some of the projects PFS is helping with this summer.

“Lifetime Fitness Consequences of Reproductive Strategies,” Dr. Jim Sedinger, University of Nevada, Reno

Since 1983, Dr. Sedinger has been studying how the reproductive strategy of nesting Brant geese in Chevak, AK, along the Bering Sea coast, has evolved as he investigates whether the nesting birds are behaving optimally (i.e., are the breeding choices they make now maximizing their current and future reproductive success?).

A female Brant goose. Photo by David Stimac

A female Brant goose. Photo by David Stimac

Sedinger and his research team study the birds’ reproductive strategies, including the number of eggs females lay, their attention to the nest, the number of goslings reared, when the eggs hatch, and more. To sample the Brant colony, Sedinger and his colleagues manipulate both the clutch and brood sizes. For example, they take goslings from one nest and give them to other breeding pairs of geese and then they document how the addition of an extra gosling affects the breeding pair’s strategy the following year.

A flock of Brant geese soar overhead. Photo by David Stimac

A flock of Brant geese soar overhead. Photo by David Stimac

Do the geese get upset when an egg or gosling goes missing?

Brant eggs in the nest. Photo by David Stimac

Brant eggs in the nest. Photo by David Stimac

“They can’t really count, so we don’t think that really affects them,” said Sedinger.

The study, funded by NSF, allows Sedinger to document and observe the short- and long-term costs and benefits of reproductive strategies. In addition, the study’s longevity provides a unique opportunity to investigate the impacts of how investments birds make early in their reproductive lives impact survival and reproduction.

A nesting pair of Brant geese. Photo by David Stimac

A nesting pair of Brant geese. Photo by David Stimac

Brant tracks. Photo by David Stimac

Brant tracks. Photo by David Stimac

“Generally what we’ve seen is that a lot of the variation among the birds seems to be associated with the conditions under which they themselves grew up,” said Sedinger. “If you have good parents that live in the right neighborhood, you have a chance of being successful yourself.”

PolarTREC, Bering Sea Integrated Ecosystem Research Project

The “TREC” part of PolarTREC stands for “Teachers & Researchers Exploring & Collaborating,” and from July 15 to Aug. 15, the collaborators include Thomas Harten, a science teacher from the Prince Frederick, MD., Dan Roby and Rosana Paredes, both of Oregon State university, and Rachael Orben of University of California, Santa Cruz. The team is studying foraging seabirds nesting in the Pribilof Islands in the Bering Sea. Their focus is on the thick-bulled Murres and blacklegged Kittiwakes and how climate warming and sea ice retreat may impact nesting and population growth.

Harten updates his blog often, and the PolarTREC team also answers individual questions.  The project contributes to a larger collaborative effort between the National Science Foundation and the North Pacific Research Board called the Bering Sea Integrated Ecosystem Research Program.

One of the Murres observed by the scientists. Photo courtesy PolarTREC

One of the Murres observed by the scientists. Photo courtesy PolarTREC

Kittiwake with chick. Photo courtesy PolarTREC

Kittiwake with chick. Photo courtesy PolarTREC

Examining the molecular and neurobiological mechanisms that regulate the circadian rhythm in the Lapland Longspur, Noah Ashley, University of Alaska.

In this NSF-funded study, post-doctoral fellow Noah Ashley is studying how the arctic breeding songbird, the Lapland Longspur’s (Calcarius lapponicus) circadian rhythms are regulated. Credited for the deep, restorative sleep that makes life possible, circadian rhythms help most organisms organize their behavior based on time and daylight. However, the Arctic’s continuous summer light (or darkness in the winter) causes many polar animals to abandon their circadian rhythm—with the exception of the Lapland Longspur. This bird follows these rhythms, despite the outside conditions.

Lapland Longspur. Photo at 1000birds.com/gallery—Lapland-Longspur.htm

Lapland Longspur. Photo at 1000birds.com/gallery—Lapland-Longspur.htm

Ashley’s study will use neurobiological techniques to examine patterns of clock gene expression in the hypothalamus and pineal gland. He’ll correlate gene expression with biological rhythms in free-living longspurs, evaluate whether those expressions are endogenous (or driven internally) and if they entrain to low-amplitude zeitgebers (signals to sleep, like light) of polar day. The study aims to further the understanding of the molecular and neurobiological basis of circadian function in polar animals.


Am I the Walrus?

August 6, 2009

Through Ed Stockard’s Viewfinder

Walrus 2 July 30 09 Ed StockardHere, perhaps, is a walrus hide in close-up, the skin rough as sandpaper, mottled with scars from hard-fought battles.

Actually, the top photo, taken by Ed Stockard from a C-130 flight deck a few days ago, depicts the scarred edge of Greenland’s ice sheet near Kangerlussuaq, the logistics hub of the National Science Foundation’s arctic research program.  The ice scrapes along the bedrock as it scooches toward the coast, tumbled and darkened by sediment from the earth below.  “This is August gnarly,” Ed writes about the particularly chewed-up appearance of the ice edge. Here’s the full shot:

Ice Edge 2 July 30 09 Ed Stockard

And another:

Ice Edge July 30 09 Ed Stockard

Further out on the ice sheet, the crevasses pictured above smooth out. Then come the summer pools of melted ice.  Ed sent a photo of some he saw about 10 minutes into his flight:

Blue pool jewels, Greenland's ice sheet treasure.

Jewel-blue melt-water pools on Greenland's ice sheet can form over the course of a few sunny days.

Sarah Das (Wood’s Hole Oceanographic Institute) has led an NSF-funded study of these melt pools for several years.  What is the process by which these pools drain, where does the water go, and what is the impact (if any) of that drainage on the coastward slide of the ice sheet? Having instrumented and studied data from several of these lakes for a few years, Das last year published some results from her work that explained the plumbing of the ice sheet. Those results, which suggest that melt-pool water makes its way to the bottom of the ice sheet, greasing the sliding mechanism and thus hastening the slippage, made–well, a splash in the media.

We liked the multimedia treatment by WHOI’s Oceanus magazine published last March.

A team is in Greenland this week servicing the melt pool research instruments.

Eating Like A Whale

August 4, 2009

Dr. Carin Ashjian of the Woods Hole Oceanographic Institution and a team will head out to the oceanic shelf near Barrow, AK., in mid-August for the second field season in a two-year study on the zooplankton that nourishes migrating bowhead whales each year.

WHOI researcher Phil Alatalo motors out to the Annika Marie, a small research vessel chartered for the zooplankton study led by Carin Ashjian. This picture courtesy of Wood's Hole Image of the Day.

WHOI's Phil Alatalo motors out to the Annika Marie, from which zooplankton research led by Carin Ashjian takes place. Source Woods Hole Oceanographic Institution

Hoping to understand the dynamics and oceanographic characteristics that provide a copius buffet of nutrient-rich organisms on the shelf near Barrow, the team also intends to gather enough information to understand the potential impact of climate change on the feeding environment. Specifically, they are interested in investigating the impact of melting sea ice and variability in Pacific water.

Steve Okkenen from the University of Alaska, Fairbanks, and Phil Alatalo from Woods Hole Oceanographic Institution deploy the Acrobat, an instrument towed by the boat to measure water temperature, salinity, and fluorescence. Source: Woods Hole Oceanographic Institute.

Steve Okkonen from the University of Alaska, Fairbanks, and Phil Alatalo deploy the Acrobat, an instrument towed by the boat to measure water temperature, salinity, and fluorescence. Source: Woods Hole Oceanographic Institution

Reached at her office, Ashjian was remarkably low-key for one about to embark on field work that will put her in the presence of whales, freezing ocean, and millions of tiny creatures (zooplankton), which have been called some of the most ecologically important aquatic species. Rather, she cautioned that her work was still in the data-gathering phase.

Bowhead whales feed on zooplankton, especially copepods and euphausiids or krill. To feed efficiently, baleen whales such as the bowhead whale and the Northern Atlantic Right whale must feed in locations where their zooplankton prey are found in abundance.

Barrow hunters prepare to bring in a whale. Results from the research may help scientists predict how climate change may affect the Arctic shelf ecosystem--and may in turn impact subsistence whaling by Inuit living in the area. Source: Winter reflections blog

Barrow hunters prepare to bring in a whale. Results from the research may help scientists predict how climate change may affect the Arctic shelf ecosystem--and may in turn impact subsistence whaling by Inuit living in the area. Source: Winter reflections blog

The shelf near Barrow is a critical feeding area for whales, and it is also a complex ecosystem whose oceanographic and atmospheric conditions impact the composition, distribution, and availability of plankton prey. To better understand the dynamics, the team will deploy three moorings in August to collect information on water currents and temperature, mammal sounds (whale vocalizations, for example), and the quantity of zooplanton present. They also will analyze ice cover via satellite imagery and analyze the gut contents of whales harvested during spring and summer hunts.

“We don’t really look at whales in the sense that someone who studies whale behavior does,” said Dr. Ashjian. “We’re really looking for the plankton.”


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