News aggregator

Photo Essay: Where the Trees Meet the Tundra

Beneath the Alaskan Tundra - Wed, 11/16/2016 - 10:36

Due to warming climate and increasing human exploitation, far northern forests and the tundra beyond are undergoing rapid changes. In northern Alaska, scientists from Columbia University’s Lamont-Doherty Earth Observatory and other institutions are studying trees at the very edge of their range to understand what to expect in coming decades. READ THE FULL SCIENTIFIC STORY  or   SEE A VIDEO

 " data-cycle-speed="750" data-cycle-center-horz="true" data-cycle-caption="#gslideshow_captions" data-cycle-caption-template="{{alt}}">
In northern Alaska, just past the arctic circle, boreal forest begins giving way to tundra. The largest ecological transition zone on earth, the so-called tree line circles the globe for more than 8,300 miles. On a June evening, Lamont-Doherty ecologist Natalie Boelman observes fast-changing weather closing in. This region is reached via the Dalton Highway, one of the few North American roads that reach this far. Built in the 1970s to serve the arctic-coast oil fields, it ends more than 500 miles beyond Fairbanks, the nearest city. The Alaska pipeline, which channels oil southward, parallels the road to the right. Further north, in a valley at the very edge of tree line in the mountains of the Brooks Range, scientists set up a laser-powered LiDAR camera to survey an acre or so. Its highly detailed 3D map of vegetation will provide information on subtle differences in topography and other elements that may allow trees to survive, or not. Lamont-Doherty plant physiologist Kevin Griffin examines a spruce, the only kind of tree capable of growing here. “If temperatures keep warming, species might change, and trees might be able to grow further north,” says Griffin. “If that happens, there will be a whole suite of consequences for ecosystems.” The tree line is altitudinal as well as latitudinal; trees living in valleys can’t survive higher elevations. Here on a windswept mountaintop above one of the team’s study sites, only plants typical of the lowland tundra further north hang on. Lamont-Doherty grad student Johanna Jensen installs a dendrometer, which will record minute changes in this spruce trunk’s diameter over the next three years. The trunk may swell or shrink daily depending on the flow of nutrients and light; if the season is mild, it may even grow a bit. Just beyond the trees, team leader Jan Eitel of the University of Idaho installs a  sensor to record total radiation reaching the plot—a key factor in plant growth. Boelman prepares to test a tree’s capacity to use sunlight for photosynthesis. At the height of summer, intense sun shines 24 hours a day. Remote-sensing specialist Lee Vierling of the University of Idaho takes fluorescence readings from spruce needles. Instruments behind him  automatically record temperature, wind speed, air pressure and humidity. In this environment, everything grows slowly. This seedling only looks like a baby; it is actually 15 or 20 years old.  Boelman and Vierling judged this spruce to be at least 96 years old, meaning it probably took root some time shortly after World War I. University of Idaho grad student Andy Maguire programs the LiDAR. In cooperation with NASA, the scientists will combine their painstaking ground observations with large-scale satellite imagery to paint a picture of how the north is changing. The north is home to a surprising diversity of animals. Here, a year-round forest-dwelling gray jay surveys its domain. In summer, vast numbers of migratory birds also come to nest. Some prefer the trees, while others inhabit only the tundra beyond, so changes in either one will have ecological fallout. The Alaska pipeline has shipped billions of barrels of oil from the oil fields of Prudhoe Bay to the south since the 1970s. The root of global warming is fossil fuel, and this region, the source of so much of it, is warming two to three times faster than the worldwide average. The oil  is starting to run out, but development is proceeding apace. Boelman checks out a fiber-optic cable being laid to Prudhoe Bay. There is now talk of a new pipeline that would carry natural gas instead of the waning oil. The most visible impact of warming climate on northern forests is increasing wildfire; this stretch along the Dalton Highway burned a couple of years ago. Each summer, huge blazes afflict Alaska, Canada and Russia; some even spread into the tundra, where fires had been previously unknown. The researchers stayed each night at the decayed early 1900s gold-mining town of Wiseman (though not at this cabin). Wiseman became reachable by road in the 1990s, and now tourists can drive here—another sign that the far north is opening up. Scott Schoppenhorst, a mechanic, has lived in Wiseman for 30 years. “Call it global warming or what you want--winters are warmer, and everything is growing faster,” he says. Here he is trying to get some grass to grow near his airplane hangar, and he is pretty optimistic it will work.   From the local perspective, the warming trend can be good; the few gardens in Wiseman are certainly benefiting. Oil and mining are pillars of Alaska’s economy, and most residents support more development. One Wiseman doorway is testimony. As human influence grows here, scientists hope to better predict how the environment will affect plants, trees, animals, people. A Wiseman fence made of caribou and moose antlers speaks to the powerful intertwining of man and nature in this region.
<
>
Further north, in a valley at the very edge of tree line in the mountains of the Brooks Range, scientists set up a laser-powered LiDAR camera to survey an acre or so. Its highly detailed 3D map of vegetation will provide information on subtle differences in topography and other elements that may allow trees to survive, or not.

Where Trees Meet Tundra, Decoding Signals of Climate Change

Beneath the Alaskan Tundra - Wed, 11/16/2016 - 10:35

In northern Alaska’s Brooks Range, the earth as most of us know it comes to an end. From Fairbanks, the northernmost city on the North American road grid, drive up the graveled Dalton Highway. Unpeopled boreal forest stretches in all directions. About 200 miles on, you pass the arctic circle, beyond which the sun never sets in midsummer, nor rises in midwinter. Eventually, the trees thin out, and look scrawnier. The rolling landscape rises into big mountains, and you are threading through the bare, razor-edged peaks of the Brooks. Midway through the mountains, scattered spruces cling only to valley bottoms; further upslope is tundra, covered only with low-lying plants. At about 320 miles from Fairbanks, you pass the last little trees. Beyond lie the barren lands of the North Slope, ending at the industrial arctic-coast hamlet of Deadhorse and the oil fields of Prudhoe Bay—the only reason this road is here at all.

 Kevin Krajick) CLICK TO VIEW A SLIDESHOW

Near the arctic circle in northern Alaska, forests begin giving way to tundra. as cold air, frozen soils and lack of sunlight squeeze out trees. Researchers are investigating how warming climate may affect the ecology of this boundary. (All photos: Kevin Krajick) CLICK TO VIEW A SLIDESHOW

The northern tree line, beyond which the climate is too harsh for trees to grow, circles all of earth’s northern landmasses for more than 8,300 miles. It is the largest ecological transition zone on the planet’s surface—a fuzzy boundary that actually loops north and south, and may appear gradual or sharp, depending on locale.

In the far north, climate is warming two to three times faster than the global average. As a result, both tundra and boreal forests are undergoing massive physical and biological shifts. But the details and the outlook remain unclear. Will warming cause forests to advance, pushing out the tundra? If so, how fast? Or will warming reduce the forests—and perhaps also tundra vegetation—by causing more wildfires and insect outbreaks? What will become of the countless birds and animals that depend on one or both environments? And will the huge amounts of carbon stored in the North’s frozen soils and its trees increase, or be released, to cause even more warming?

The tree line is the longest ecological transition zone on earth's surface, circling through the northern landmasses of North America and Eurasia for some 8,300 miles. Here, the tundra beyond the trees is in red. At bottom right is Alaska, where researchers are now working in the area just beyond the arctic circle.

The tree line is the longest ecological transition zone on earth’s surface, circling through the northern landmasses of North America and Eurasia for some 8,300 miles. Here, the region beyond the trees is in red. At bottom right is Alaska, where researchers are now working in the area just beyond the arctic circle. (Map courtesy of U.S. Fish and Wildlife Service)

To  help answer these questions, scientists from Columbia University’s Lamont-Doherty Earth Observatory and other institutions are engaged in a long-term project to sort out what allows trees to survive or not in this borderline environment. They have set up monitoring plots, conveniently located along the highway, at the edge of the trees. Here, instruments will continuously measure air and soil temperature, precipitation, wind speed, humidity and other parameters for the next several years, and compare these with the growth and survival of trees. The fieldwork is part of the larger Arctic Boreal Vulnerability Experiment (ABoVE), a multiyear NASA-sponsored project that seeks to combine large-scale satellite observations of the northern regions with these fine-scale ground studies.

Natalie Boelman, an ecologist at Columbia University’s Lamont-Doherty Earth Observatory, measures the height of trees at one study plot.

Natalie Boelman, an ecologist at Columbia University’s Lamont-Doherty Earth Observatory, measures the height of trees at one study plot.

“There are many conditions that affect whether trees can and cannot grow,” says Lamont-Doherty plant physiologist Kevin Griffin. The main one is heat; trees generally are viable only where the mean growing-season temperature is above about 6.4 degrees C (about 43.5 degrees F). But that is not the whole answer, says Griffin. “We also know it’s things like water, wind, nutrients, how much light is received, whether it’s direct or diffuse light, snow cover in the winter—it’s a complex combination. How that all works, that’s precisely what we’d like to find out.”

Led by Jan Eitel, a forest scientist at the University of Idaho, the scientists arrived by pickup truck in early June to set up the plots. Almost no one lives between Fairbanks and Deadhorse, but they were able to put up at a lodge in the onetime gold-mining settlement of Wiseman, a mostly deserted huddle of cabins (current population about 20) dating from the early 1900s that lies near the highway. From here, the scientists commuted daily to a half-dozen sites, chosen for their sharp ecological edges; at each one, you could walk from the trees right into adjoining tundra, just slightly upslope. The most northerly plot is near a onetime modest landmark, the so-called Last Spruce, a starved-looking tree marked with a metal sign that said “Farthest North Spruce Tree on the Alaskan Pipeline – Do Not Cut.” A year or so ago, someone cut it down.

Trees grow very slowly here; this one that Boelman is examining is about 15 years old.

Trees grow very slowly here; this one that Boelman is examining is about 15 years old.

Part of the project involves mapping the sites with LiDAR, a surveying technology that shoots a pulsing laser to create an exquisitely detailed 3D landscape map. Accurate down to a few centimeters, it maps ground layout, individual tree branches and plant cover. In this environment, where trees are barely hanging on, the tiniest bits of variation in topography or temperature might make a life-or-death difference for a seedling; a bed of deep moss may swaddle it in warmth; a subtle swale, projecting boulder or another tree might protect it from raking winds.

But most far northern soils are permanently frozen just below the surface, and warming climate is not altering the fearfully small amount of light reaching plants much of the year. A neighboring tree might also cast just enough shade so that a seedling cannot get enough light and warmth, and a too-dense stand of trees might reduce the overall soil temperature they themselves need for rooting and uptake of nutrients. The surveys, repeated every few days by automated cameras, are designed to show how the landscape changes over time.

Shrubby deciduous dwarf willows and aspens grow here, but the only real trees this far north are the spruces. Once one takes root, it grows slowly—very slowly. One day University of Idaho remote-sensing specialist Lee Vierling and Lamont ecologist Natalie Boelman aged some smaller ones by counting whorls—the bit of stem that sprouts from the top each growing season. One Christmas-tree size spruce reaching just over their heads turned out to be 96 years old; it had apparently started growing in 1920.

“Woodrow Wilson was president then,” said Vierling. “World War I was just over.” The tallest trees reach 20 to 30 feet, a height that spruces can reach in a decade or two further south; these have probably stood for 200 to 300 years.

Lamont-Doherty plant physiologist Kevin Griffin checks an instrument designed to monitor a spruce tree’s photosynthetic activity.

Lamont-Doherty plant physiologist Kevin Griffin checks an instrument designed to monitor a spruce tree’s photosynthetic activity.

Warmer weather is almost certain to make these trees grow faster, and such weather is already here. With 24-hour daylight, the team worked up to 14 hours a day, much of the time sweating in intense sun. Around this time, the thermometer up at Deadhorse hit an all-time record of 85 degrees F—identical to New York’s Central Park that same day.

“The trees are really booming here,” said the team’s hostess in Wiseman, Heidi Schoppenhorst, who has lived here her whole life. “The climate is warming, and there’s more rain in June, when it really matters.”

There is already evidence from satellite imagery that the tundra beyond is becoming greener and shrubbier. Many scientists expect the tree line to advance eventually, and some studies purport to show that this is already happening. Some models predict that half the current tundra could be converted by 2100, though others say the process would be much slower. On the other hand, some studies assert the trees are actually retreating in areas, as heat dries forests, helping invasive insects and fires to destroy growing areas.

In Alaska, fires are predicted by one study to grow fourfold in coming decades, and it is already being ravaged; on the way up, the scientists passed through several big tracts reduced in the past few years to blackened sticks. This year a fire around Fort McMurray, in northern Alberta, drove out 80,000 residents and leveled part of the city. A few years ago, Boelman was part of a team that studied a 2007 lightning-sparked fire that burned 400 square miles of tundra on the North Slope—the biggest tundra fire ever recorded, in an area where thousands of years may go by without any fire at all.

Team leader Jan Eitel of the University of Idaho sets up a solar-powered radar camera that will scan a study site continuously for years, to capture how trees respond to changing conditions.

Team leader Jan Eitel of the University of Idaho sets up a solar-powered radar camera that will scan a study site continuously for years, to capture how trees respond to changing conditions.

“The differences between tundra and trees are really interesting, especially since one is predicted to start encroaching on the other,” said Boelman, stroking the needles of a nearby spruce about up to her shoulder, but probably much older than she is.

Boelman is part of a separate ABoVE project in which researchers are radiotagging northern animals including caribou, bears, moose, wolves and eagles, to see where they travel in relation to changing fire and weather conditions. Boelman has been working in northern Alberta tagging American robins, which are known to inhabit wide ranges and migrate vast distances. If anecdotal evidence means anything, the trend could be northward; in the last 20 years, some Inuit communities who had never seen robins before have had to invent a name for them: “Koyapigaktoruk.”

On her first trip to the north, Lamont-Doherty graduate student Johanna Jensen takes down data on a wired-up spruce. The study will provide not only long-term information on climate change, but opportunities for young scientists to work directly in the field.

On her first trip to the north, Lamont-Doherty graduate student Johanna Jensen takes down data on a wired-up spruce. The study will provide not only long-term information on climate change, but opportunities for young scientists to work directly in the field.

A few days after installing complex arrays of sensors, cameras and data loggers, along with solar panels and tangles of wires to connect them, the scientists discovered an unexpected wildlife phenomenon: Rabbits, rampant in the forest, loved chewing through the wires, and their equipment was blinking out. The team quickly made repairs and improvised defenses, burying the wires in spongy moss or surrounding them with palisades of sharp, dead sticks. Plans were laid for obtaining chicken wire for a more permanent solution.

Rabbits do not thrive like this in tundra, but if the trees and shrubs move northward, the rabbits will probably move with them. So will other creatures that favor such habitats, such as lynx, moose, black bears and white-crowned sparrows. Those who favor tundra would then have to adapt or get nudged out; these include musk oxen and open-area nesting birds such as Lapland longspurs and ptarmigans. Some animals, including barren-ground caribou and wolves, move seasonally between the two.

Boelman is neutral about the outcome. “People assume that when the ecosystem changes, it’s going to be all bad.” she said. But, she said “with climate change, there are almost always winners and losers. Some species will suffer, but others will benefit.”

Along the Dalton Highway itself, change is happening fast. Near the study sites, workers were digging an endless ditch to lay a fiber-optic line to Deadhorse. Intrepid tourists, encouraged by the mild weather, passed by in heavily laden vehicles and waved. A man pushing a large stroller-type contraption southward was said to be on a mission to walk from Deadhorse to Austin, Tex. Giant trucks raced northward carrying cable, pipes, prefab buildings. Some were carrying gasoline, against the pipeline flow of oil going in the opposite direction. The fossil-fuel circle was being completed; refined energy was heading back to help keep up the production of raw energy.

 

Save

Save

Save

A Front Row Seat on the Ocean Floor

Cruising to an OASIS - Tue, 11/15/2016 - 14:12

By Bridgit Boulahanis

Ocean scientists are, in their hearts, explorers. Our group aboard the R/V Atlantis may be more infected with the exploration bug than most. The first goal of our expedition makes that clear: We aim to map regions of the seafloor never before seen by human eyes. After a two-day transit to our survey site, the first four days of our research program are dedicated solely to mapping.

An unexplored seamount is our first mapping target. Prior to our expedition, the region was only known to be a shallow area because of satellite-derived maps. Information from satellites gives scientists the global seafloor map that we use in the absence of data of better quality. Unfortunately, this data resolution is on the order of a kilometer, which provides a general idea of the major features of a region but misses many crucial details that may be scientifically important.

With our shipboard mapping system, we can create maps at 75-meter resolution. This is similar to the difference between seeing that there is a large green feature in the middle of the island of Manhattan, and being able to pick out the exact location of the Delacorte Theater within the park.

Watching the Liona Seamount come into focus.

Scientists aboard Atlantis watch the Liona Seamount come into focus.

Knowing all of this, it makes sense that when the R/V Atlantis arrived on station to map what was this week dubbed, the entire science party was gathered in front of one computer. As each new swath of data came in, scientists called out features they could immediately identify and began debating the origin and age of the seamount springing up before our eyes.

This is just the first stage of exploration and discovery for our month-long expedition. Liona Seamount stands at the western edge of a long chain of seamounts extending from the East Pacific Rise at a latitude of approximately 8°20’N. Our mission, titled Off-Axis Seamount Investigations at Siqueiros (OASIS), aims to characterize this entire chain of submarine volcanoes. We will use every resource at our disposal to increase scientific understanding of these seamounts.

The Liona seamount.

A 3D map of Liona Seamount. Courtesy of Dan Fornari and Trish Greg

The next phase of our survey will include even higher resolution maps made by the Autonomous Underwater Vehicle Sentry. If our shipboard maps revealed the Delacorte Theater in Central Park, Sentry’s maps would allow us to see people sitting in the seats. We will also be utilizing cameras designed to be towed just above the seafloor and provide thousands of high-resolution images of the features below.

Physical samples of rocks from our seamounts are also crucial to this study, and will be brought on board through overnight dredging and collection using the research submarine Alvin.

The first round of data is already in the hands of the eight graduate students aboard, rapidly being processed and parsed for in-depth analysis. In addition to new maps covering several hundred kilometers of seafloor, we have collected magnetic data giving us the approximate age of the seamounts we are studying, and gravity data that will help us to gain a rough understanding of the structure of the oceanic crust.

The results we have gotten so far are thrilling, but no doubt some of the most exciting data of our expedition is still ahead of us.

bridgit-boulahanisBridgit Boulahanis, a graduate student at Lamont-Doherty Earth Observatory, is sailing in the eastern Pacific Ocean aboard the R/V Atlantis on an expedition to investigate a chain of submarine volcanoes along the East Pacific Rise. Learn more about the expedition on the OASIS Facebook page and YouTube channel.

The Domino Effect

Tracking Antarctica's Ice Shelves - Mon, 11/14/2016 - 22:45
Along the edge of the Antarctic Peninsula. (photo M. Turrin)

Along the edge of the Antarctic Peninsula, large chunks of ice flow freely from the land into the ocean. Photo: M. Turrin

Ice shelves can behave like dominos. When they are lined up and the first one collapses it can cause a rippling effect like dominos. We have seen this with the Larsen ice shelves. Named in series, the Larsen A, B and C shelves extended along the northeastern edge of the West Antarctic Peninsula, and covered a large swath of coastline as recently as 20 years ago. Bordering the western edge of the Weddell Sea, each extended from a separate embayment yet merged into a large expanse of ice, considered one ice shelf complex. All this was before 1995, before the dominoes began to collapse.

Glacier on the Antarctic Peninsula moving. (Photo M. Turrin)

In this area of the Antarctic Peninsula, ice moves as if it is on a conveyor belt, flowing down between the mountain peaks and toward the ocean. You can see here it is building an ice moraine as it flows. This stretch of glaciers flows onto the Larsen catchment. Photo: M. Turrin

It was January 1995, toward the end of the austral summer, when Larsen A, the smallest of the three shelves, broke apart rather suddenly and was gone. The furthest north of the Larsen trio, this small shelf was situated just north of the Larsen B and just outside of the Antarctic Circle. Due to its size and location, the 1,500-square-kilometer block of ice was the most vulnerable of the three Larsen shelves. Warming water that had been moving around the peninsula was the probable cause for the demise.

The Larsen ice shelf complex, as it was and what it is now. (Images from NASA, compilation from Carbon Copy)

The Larsen ice shelf complex. Images: NASA; compilation: Carbon Copy

When Larsen A disappeared, Larsen B immediately became more vulnerable. Although twice the size at 3,250 square kilometers, the shelf was now un-buffered from warming ocean waters to the north; this combined with several warm summers and Larsen B weakened and became destabilized. In 1998, satellites captured evidence of the front edge of Larsen B beginning to change. Satellite images pointed out melt water ponds on the surface of the shelf, but with some 220 meters of ice thickness, these ponds did not seem to pose a threat. Then between early February and early March 2002, the shelf suffered a massive collapse, with section after section all but evaporating before our eyes. There was disbelief among the science community that a section of shelf this size, and one that had been relatively stable for an estimated 10,000-12,000 years, could so swiftly suffer a collapse. The second domino had fallen.

The Antarctic Peninsula has elevation rising 8000 ft. with ice covering the tops of the mountains in thick layers. (Photo M. Turrin)

The Antarctic Peninsula has elevation rising 8,000 ft., with ice covering the tops of the mountains in thick layers. Photo: M. Turrin

With the loss of a significant section of the Larsen shelf complex, there was a subsequent acceleration of the glaciers that had once been braced by the shelves’ protective presence. Without the stable pressure pushing back against these glaciers, the ice sheet in this area accelerated by up to 300 percent, transferring ice from the Antarctic continent into the ocean and contributing more ice to sea level rise. With the acceleration came a rapid loss in size in the glaciers feeding the Larsen area.

Larsen C and the crack that has developed mapped through time. (Modis imagery annotated by the MIDAS project.)

Larsen C and the crack that has developed, mapped through time. Image: Modis imagery annotated by the MIDAS project

Larsen C remains the fourth largest of the ice shelves by a few hundred square kilometers of ice. A crack appeared in the shelf in 2011 and has grown in size over the subsequent years. Set back about 20 kms. from the edge of the shelf, it threatens to break off about 8 percent of the shelf, or a chunk of ice about the same size as the state of Delaware, at ~6,000 sq. km. With the crack set so far back, there is concern that it might threaten the integrity of the larger ice sheet, weakening the support that holds the shelf in place.

Crack in the Larsen C Ice Shelf that continues to spread, even in the winter months. (Photo M. Turrin)

Crack in the Larsen C Ice Shelf that continues to spread, even in the winter months. Photo: M. Turrin

Just as Larsen B revealed the speed with which an ice shelf can collapse, Larsen C may be poised to reveal how quickly a large crack can propagate along the shelf. The rift is growing even during the Antarctic winter, adding an additional 22 kms. to a length of 130 kms. in total during the last austral winter between March and August 2016. In addition, the crack has widened from 200 meters to 350 meters. Overflying the crack, we were able to collect high resolution imagery that will help with tracking the fate of the third domino in the lineup.

Section of the deep crack in the Larsen C ice shelf. (Digital Mapping System from the IceBridge Project.)

A section of the deep crack in the Larsen C ice shelf collected by high resolution imagery using the Digital Mapping System as part of the IceBridge Project. Photo: DMS team, IceBridge

IceBridge: Since 2009, the NASA IceBridge project has brought together science teams to monitor and measure each of the ice features in order to improve our understanding of changes in the climate system and our models. Lamont-Doherty, under lead scientists Jim Cochran and Kirsty Tinto, has led up the gravity and magnetics measurements for these campaigns.

http://www.ldeo.columbia.edu/icebridge

http://www.ldeo.columba.edu/rosetta

Save

The Domino Effect

Ice Bridge Blog - Mon, 11/14/2016 - 22:45
Along the edge of the Antarctic Peninsula. (photo M. Turrin)

Along the edge of the Antarctic Peninsula, large chunks of ice flow freely from the land into the ocean. Photo: M. Turrin

Ice shelves can behave like dominos. When they are lined up and the first one collapses it can cause a rippling effect like dominos. We have seen this with the Larsen ice shelves. Named in series, the Larsen A, B and C shelves extended along the northeastern edge of the West Antarctic Peninsula, and covered a large swath of coastline as recently as 20 years ago. Bordering the western edge of the Weddell Sea, each extended from a separate embayment yet merged into a large expanse of ice, considered one ice shelf complex. All this was before 1995, before the dominoes began to collapse.

Glacier on the Antarctic Peninsula moving. (Photo M. Turrin)

In this area of the Antarctic Peninsula, ice moves as if it is on a conveyor belt, flowing down between the mountain peaks and toward the ocean. You can see here it is building an ice moraine as it flows. This stretch of glaciers flows onto the Larsen catchment. Photo: M. Turrin

It was January 1995, toward the end of the austral summer, when Larsen A, the smallest of the three shelves, broke apart rather suddenly and was gone. The furthest north of the Larsen trio, this small shelf was situated just north of the Larsen B and just outside of the Antarctic Circle. Due to its size and location, the 1,500-square-kilometer block of ice was the most vulnerable of the three Larsen shelves. Warming water that had been moving around the peninsula was the probable cause for the demise.

The Larsen ice shelf complex, as it was and what it is now. (Images from NASA, compilation from Carbon Copy)

The Larsen ice shelf complex. Images: NASA; compilation: Carbon Copy

When Larsen A disappeared, Larsen B immediately became more vulnerable. Although twice the size at 3,250 square kilometers, the shelf was now un-buffered from warming ocean waters to the north; this combined with several warm summers and Larsen B weakened and became destabilized. In 1998, satellites captured evidence of the front edge of Larsen B beginning to change. Satellite images pointed out melt water ponds on the surface of the shelf, but with some 220 meters of ice thickness, these ponds did not seem to pose a threat. Then between early February and early March 2002, the shelf suffered a massive collapse, with section after section all but evaporating before our eyes. There was disbelief among the science community that a section of shelf this size, and one that had been relatively stable for an estimated 10,000-12,000 years, could so swiftly suffer a collapse. The second domino had fallen.

The Antarctic Peninsula has elevation rising 8000 ft. with ice covering the tops of the mountains in thick layers. (Photo M. Turrin)

The Antarctic Peninsula has elevation rising 8,000 ft., with ice covering the tops of the mountains in thick layers. Photo: M. Turrin

With the loss of a significant section of the Larsen shelf complex, there was a subsequent acceleration of the glaciers that had once been braced by the shelves’ protective presence. Without the stable pressure pushing back against these glaciers, the ice sheet in this area accelerated by up to 300 percent, transferring ice from the Antarctic continent into the ocean and contributing more ice to sea level rise. With the acceleration came a rapid loss in size in the glaciers feeding the Larsen area.

Larsen C and the crack that has developed mapped through time. (Modis imagery annotated by the MIDAS project.)

Larsen C and the crack that has developed, mapped through time. Image: Modis imagery annotated by the MIDAS project

Larsen C remains the fourth largest of the ice shelves by a few hundred square kilometers of ice. A crack appeared in the shelf in 2011 and has grown in size over the subsequent years. Set back about 20 kms. from the edge of the shelf, it threatens to break off about 8 percent of the shelf, or a chunk of ice about the same size as the state of Delaware, at ~6,000 sq. km. With the crack set so far back, there is concern that it might threaten the integrity of the larger ice sheet, weakening the support that holds the shelf in place.

Crack in the Larsen C Ice Shelf that continues to spread, even in the winter months. (Photo M. Turrin)

Crack in the Larsen C Ice Shelf that continues to spread, even in the winter months. Photo: M. Turrin

Just as Larsen B revealed the speed with which an ice shelf can collapse, Larsen C may be poised to reveal how quickly a large crack can propagate along the shelf. The rift is growing even during the Antarctic winter, adding an additional 22 kms. to a length of 130 kms. in total during the last austral winter between March and August 2016. In addition, the crack has widened from 200 meters to 350 meters. Overflying the crack, we were able to collect high resolution imagery that will help with tracking the fate of the third domino in the lineup.

Section of the deep crack in the Larsen C ice shelf. (Digital Mapping System from the IceBridge Project.)

A section of the deep crack in the Larsen C ice shelf collected by high resolution imagery using the Digital Mapping System as part of the IceBridge Project. Photo: DMS team, IceBridge

IceBridge: Since 2009, the NASA IceBridge project has brought together science teams to monitor and measure each of the ice features in order to improve our understanding of changes in the climate system and our models. Lamont-Doherty, under lead scientists Jim Cochran and Kirsty Tinto, has led up the gravity and magnetics measurements for these campaigns.

http://www.ldeo.columbia.edu/icebridge

http://www.ldeo.columba.edu/rosetta

Save

In Bangladesh, Arsenic Poisoning Is a Neglected Issue - The Lancet

Featured News - Sat, 11/12/2016 - 12:00
Millions of people in Bangladesh are still being exposed to arsenic in their drinking water, decades after the problem was identified. The Lancet talks with Lamont's Lex van Geen about his work on arsenic in drinking water in South Asia.

How Did Climate and Humans Respond to Past Volcanic Eruptions? - Eos

Featured News - Fri, 11/11/2016 - 10:00
To predict and prepare for future climate change, scientists are striving to understand how global-scale climatic change manifests itself on regional scales and also how societies adapt—or don’t—to sometimes subtle and complex climatic changes.These issues were at the heart of the inaugural workshop of the Volcanic Impacts on Climate and Society (VICS) Working Group, convened at Lamont-Doherty Earth Observatory.

A first meeting with an old friend

Tracking Antarctica's Ice Shelves - Thu, 11/10/2016 - 22:09
Pine Island Ice Shelf

As we fly over Pine Island Glacier, West Antarctica the blowing snow adds a surreal quality to the 200 ft. high towering edge of the ice shelf. (Photo M. Turrin)

If you have studied the impacts of climate on Antarctica you have encountered Pine Island Glacier. Tucked in at an angle under the West Antarctic Peninsula handle, this seemingly innocuous glacier has been making headlines for years as one of the fastest flowing ice stream glaciers on Earth. In Antarctica, Pine Island pushes ice at a rapid clip into Pine Island Bay part of the larger Amundsen Sea. So although we have never met face to face, Pine Island is a glacier I have known for years.

Antarctica has two large ice sheets, sensibly labeled the West Antarctic Ice Sheet and the East Antarctica Ice Sheet and separated by the looming Transantarctic Mountains that break through above the thick layer of ice covering much of Antarctic’s surface. In large part West Antarctica is comprised of the Antarctic Peninsula, the handle shaped extension of the continent reaching out towards South America, but below that there is a vulnerable area that drains into Amundsen Sea, one of three catchment areas for this ice sheet. Glaciers in this region have been changing rapidly, led by Pine Island and the neighboring Thwaites. If melted, the ice from Pine Island and Thwaites glaciers together, has the capacity to raise global sea level by up to 2 meters (~7 feet.)

velocity map

The red color represents the fast moving ice of Pine Island glacier in this velocity map on the left. On the left side is a map of subglacial topography showing in dark blue the deep trough that underlies the glacier. (credit velocity map E. Rignot)

For Pine Island the vulnerability results from a compounding of challenges, a small ice shelf offering little support to the land ice behind and little protection from the warming ocean water that makes its way up onto the shelf. In addition the base of the glacier rests on land that is backward sloping, or tipping back underneath the ice. A retrograde bed, as these are called, allows the warm ocean water access to move back under the glacier, further destabilizing and acceleration ice flow.

Crevassing in the ice shows areas where there is strain from ice flowing at different rates. Ice will often crevasse as it accelerates. (Photo M. Turrin)

Crevassing, or deep cuts in the ice, shows areas where there is strain from ice flowing at different rates. Ice will often crevasse as it accelerates, as is shown in this heavily crevassed ice flowing out from the Pine Island ice shelf.  (Photo M. Turrin)

At 160 miles of length, and 68,000 square miles of catchment, Pine Island handles the drainage for approximately one tenth of the West Antarctic Ice Sheet. Over the last forty years it has been over-performing, accelerating its flow, and is attributed with one quarter of Antarctica’s current ice loss. In its years of operation (2003-2010), Ice Sat I satellite  provided us with a series of measurements for this glacier showing that Pine Island Glacier was moving more ice into the ocean than any other drainage basin worldwide. Since 2009 the IceBridge project has continued this monitoring, extending our data for this region so that we won’t miss critical information while IceSat II is being prepared for a 2018 launch. Pine Island glacier measurements are critically important to help us project global sea level rise.

On the DC8

On board the DC8 there is a flight command center with a very busy team that works between the science team and the air crew to ensure the science is completed safely and as designed. (photo M. Turrin)

Pine Island glacier is shrinking. As the glacier has accelerated its flow, the ice stream has thinned and correspondingly the face of the glacier has lost elevation. In some areas ice elevation loss has equaled 4 meters or more a year. The drop in elevation is more  quadruple the annual precipitation for the area, and has occurred in both summer and winter.

Crevasse

Ice Bridge laser image of the crack in Pine Island Glacier. The deep blue line bisecting the front of the glacier is the crack or crevasse in the ice. The depth of the crack that cuts in from the edge of the ice shelf is close to 40 meters deep in this area. (image NASA IceBridge)

More bad news may be ahead for Pine Island. Although the glacier does not have a large ice shelf, there is a relatively small shelf that helps to restrain some of the flow from land to ocean. However, in the last decade a fairly significant crack has developed in the shelf threatening to pull off another large chunk of ice and relaxing the hold the shelf has on the ice behind. As we overflew two locations IceBridge surface laser measurements captured the crack depth at 60 and 70 meters deep. This crack has continued to expand over the last few years and it is only a matter of time before this section of shelf will separate moving off into the ocean and leaving the ice shelf more exposed.

The Pine Island Glacier crack extending back into the glacier. (Photo M. Turrin)

The Pine Island Glacier crack extending back into the glacier. (Photo M. Turrin)

IceBridge: Since 2009, the NASA IceBridge project has brought together science teams to monitor and measure each of the ice features in order to improve our understanding of changes in the climate system and our models. Lamont-Doherty, under lead scientists Jim Cochran and Kirsty Tinto, has led up the gravity and magnetics measurements for these campaigns.

http://www.ldeo.columbia.edu/icebridge

http://www.ldeo.columba.edu/rosetta

A first meeting with an old friend

Ice Bridge Blog - Thu, 11/10/2016 - 22:09
Pine Island Ice Shelf

As we fly over Pine Island Glacier, West Antarctica the blowing snow adds a surreal quality to the 200 ft. high towering edge of the ice shelf. (Photo M. Turrin)

If you have studied the impacts of climate on Antarctica you have encountered Pine Island Glacier. Tucked in at an angle under the West Antarctic Peninsula handle, this seemingly innocuous glacier has been making headlines for years as one of the fastest flowing ice stream glaciers on Earth. In Antarctica, Pine Island pushes ice at a rapid clip into Pine Island Bay part of the larger Amundsen Sea. So although we have never met face to face, Pine Island is a glacier I have known for years.

Antarctica has two large ice sheets, sensibly labeled the West Antarctic Ice Sheet and the East Antarctica Ice Sheet and separated by the looming Transantarctic Mountains that break through above the thick layer of ice covering much of Antarctic’s surface. In large part West Antarctica is comprised of the Antarctic Peninsula, the handle shaped extension of the continent reaching out towards South America, but below that there is a vulnerable area that drains into Amundsen Sea, one of three catchment areas for this ice sheet. Glaciers in this region have been changing rapidly, led by Pine Island and the neighboring Thwaites. If melted, the ice from Pine Island and Thwaites glaciers together, has the capacity to raise global sea level by up to 2 meters (~7 feet.)

velocity map

The red color represents the fast moving ice of Pine Island glacier in this velocity map on the left. On the left side is a map of subglacial topography showing in dark blue the deep trough that underlies the glacier. (credit velocity map E. Rignot)

For Pine Island the vulnerability results from a compounding of challenges, a small ice shelf offering little support to the land ice behind and little protection from the warming ocean water that makes its way up onto the shelf. In addition the base of the glacier rests on land that is backward sloping, or tipping back underneath the ice. A retrograde bed, as these are called, allows the warm ocean water access to move back under the glacier, further destabilizing and acceleration ice flow.

Crevassing in the ice shows areas where there is strain from ice flowing at different rates. Ice will often crevasse as it accelerates. (Photo M. Turrin)

Crevassing, or deep cuts in the ice, shows areas where there is strain from ice flowing at different rates. Ice will often crevasse as it accelerates, as is shown in this heavily crevassed ice flowing out from the Pine Island ice shelf.  (Photo M. Turrin)

At 160 miles of length, and 68,000 square miles of catchment, Pine Island handles the drainage for approximately one tenth of the West Antarctic Ice Sheet. Over the last forty years it has been over-performing, accelerating its flow, and is attributed with one quarter of Antarctica’s current ice loss. In its years of operation (2003-2010), Ice Sat I satellite  provided us with a series of measurements for this glacier showing that Pine Island Glacier was moving more ice into the ocean than any other drainage basin worldwide. Since 2009 the IceBridge project has continued this monitoring, extending our data for this region so that we won’t miss critical information while IceSat II is being prepared for a 2018 launch. Pine Island glacier measurements are critically important to help us project global sea level rise.

On the DC8

On board the DC8 there is a flight command center with a very busy team that works between the science team and the air crew to ensure the science is completed safely and as designed. (photo M. Turrin)

Pine Island glacier is shrinking. As the glacier has accelerated its flow, the ice stream has thinned and correspondingly the face of the glacier has lost elevation. In some areas ice elevation loss has equaled 4 meters or more a year. The drop in elevation is more  quadruple the annual precipitation for the area, and has occurred in both summer and winter.

Crevasse

Ice Bridge laser image of the crack in Pine Island Glacier. The deep blue line bisecting the front of the glacier is the crack or crevasse in the ice. The depth of the crack that cuts in from the edge of the ice shelf is close to 40 meters deep in this area. (image NASA IceBridge)

More bad news may be ahead for Pine Island. Although the glacier does not have a large ice shelf, there is a relatively small shelf that helps to restrain some of the flow from land to ocean. However, in the last decade a fairly significant crack has developed in the shelf threatening to pull off another large chunk of ice and relaxing the hold the shelf has on the ice behind. As we overflew two locations IceBridge surface laser measurements captured the crack depth at 60 and 70 meters deep. This crack has continued to expand over the last few years and it is only a matter of time before this section of shelf will separate moving off into the ocean and leaving the ice shelf more exposed.

The Pine Island Glacier crack extending back into the glacier. (Photo M. Turrin)

The Pine Island Glacier crack extending back into the glacier. (Photo M. Turrin)

IceBridge: Since 2009, the NASA IceBridge project has brought together science teams to monitor and measure each of the ice features in order to improve our understanding of changes in the climate system and our models. Lamont-Doherty, under lead scientists Jim Cochran and Kirsty Tinto, has led up the gravity and magnetics measurements for these campaigns.

http://www.ldeo.columbia.edu/icebridge

http://www.ldeo.columba.edu/rosetta

Non-Profit, Lamont Team Up for Sustainability Program - Orangetown Daily Voice

Featured News - Wed, 11/09/2016 - 17:07
Students from nine Rockland County high schools will get hands-on experience at land use planning at collaborative workshops with Columbia University's Lamont-Doherty Earth Observatory and Rockland Conservation Service Corps.

Poaching on the Rise — Most Illegal Ivory Comes from Recently Killed Elephants - The Verge

Featured News - Wed, 11/09/2016 - 16:55
Almost all the world’s illegal ivory comes from elephants that have been recently killed, according to a new study from Lamont's Kevin Uno.

Recently Killed Elephants Are Fueling the Ivory Trade - Science Magazine

Featured News - Mon, 11/07/2016 - 12:00
The illegal trade in elephant ivory is being fueled almost entirely by recently killed African elephants, not by tusks leaked from old government stockpiles, as had long been suspected. That’s the conclusion of a new study from Lamont's Kevin Uno that relies on nuclear bomb tests carried out in the 1950s and ’60s to date elephant tusks.

Year by Year, Line by Line, We Build an Image of Getz Ice Shelf

Ice Bridge Blog - Sun, 11/06/2016 - 16:16
Grease Ice

Newly formed sea ice called “grease ice” looks like thin layers of mica along the front of the Getz Ice Shelf, Antarctica. Photo: M. Turrin

Antarctic ice appears in a range of types and sizes, from the newly formed skim of ice on the ocean called grease ice (above), to the older meter thick layers of sea ice, to chunks of icebergs, floating reaches of ice shelves, and finally the massive land based Antarctic ice sheet. Each part of this ice inventory has a unique role in the larger climate system, but they also work together. As part of this year’s IceBridge Antarctic flight campaign, we are focused largely on the coastline to build a better understanding of the interaction of these different pieces in the ice system. This understanding is central to improving our climate models.

Break in Ice Shelf

Evidence of a break along the front edge of Getz Ice Shelf, Antartica. In the foreground a mixture of newly forming sea ice has mixed with icebergs to form what is called “brash ice.” Photo: M. Turrin

The focus today is on Getz ice shelf. Ice shelves form when ice flows off the land into the surrounding ocean, forming a thick apron of attached, but floating ice. The Getz shelf extends out several miles from where the glacier empties into the ocean. The shelves are deep floating blocks of ice ~ a km thick where they first meet the ocean and thinned to several hundred meters thick at their front edge. They are critical for the future stability of the Antarctic ice sheet as they provide a barrier that holds back the continental ice sheet, braking its flow from land into the ocean.

Image noting the location of some of the larger ice shelves around Antarctica (Image T. Scambos NSIDC)

Image noting the location and size of  a dozen or so of the larger ice shelves around Antarctica. Image: T. Scambos NSIDC

In all ~ 45 ice shelves adorn almost half the Antarctica coastline, and represent an area of ~1.5 million km², close to 10 percent of the total ice that covers Antarctica. Ten of these are considered major shelves, with the largest two nestled in the junctures where East and West Antarctic meet, filling in the space with California-sized blocks of ice: the Ross Ice Shelf (at 472,960 km²), where Lamont-Doherty currently has another Antarctic research project called Rosetta running, and the Filchner-Ronne (422,420 km²) across from it. Many of the shelves are smaller, yet each serves a valuable role in Antarctic ice stability, and thus they are a prime focus for examining change in Antarctica.

Tabular icebergs after separating fro the ice shelf line up along the front of Getz before moving out into the ocean. (Photo M. Turrin)

Large tabular icebergs after separating from the ice shelf line up along the front of Getz before moving out into the ocean. Photo: M. Turrin

Changes in Antarctic ice have been dominated by the interaction of the ice and the ocean, and because ice shelves extend out into the water, they are vulnerable to melt from the warmer ocean water. Melt can affect them in two ways, through thinning along their length and through causing a retreat of the “grounding line.”  The grounding line is the critical spot where the ice goes from being frozen all the way to the ocean floor (or bed) to where it begins to float in the ocean. The grounding line retreat results from warm water melting the ice back from its frozen base. Tracking any changes to the location of the grounding line tells us a lot about the vulnerability of the ice shelf and is critical to setting models.

Ice shelves sit primarily below the ocean surface. Getz measures close to 200 ft. at the front but with another 1000 ft. below the surface. The rich blue color along the front edge is from that deep reaching ice front. (Photo M. Turrin)

Ice shelves sit primarily below the ocean surface. Getz measures close to 200 ft. elevation above the ocean at the front, but has another 1000 ft. of ice below the surface. The rich blue color along the front edge is from that deep reaching ice front. Photo: M. Turrin

Getz ice shelf is our furthest flight mission of the campaign at close to 12 hours of flying, and it is our fifth mission this week, with each one clocking 11 plus hours of flight with prep and wrap-up added on either end. It could feel a bit like a rerun of the same movie, but it never does, and the wear of the long days doesn’t appear to show on the team. The purpose of today is to continue mapping the sub ice-shelf bathymetry using our gravimeter, as well as the ice surface and bedrock upstream of the grounding line using laser and radar. We need a complete look at the grounding line and the bed under the ice shelf, where warm ocean water can move in and circulate under the ice, in order to improve our models. Gravity is critical for uncovering the surface depths and contours under the ice shelves, as none of the other instruments on board are able to collect data through the water that lies under the shelf.

Mountain Protrusion

A set of mountains protrudes up through the ice at the west end of the survey line along the edge of the Getz Ice Shelf. Photo: M. Turrin

Because of the distance to Getz from our daily starting point in Chile, we have been building a set of data over a series of years, line by line. Each year we collect a repeat track and a new track. We know Getz has changed. Eighteen months ago in March 2015, a NASA image from space captured a Manhattan-sized iceberg (17 miles long) breaking off of Getz Ice Shelf. This break appears to have occurred at the end of the last austral summer in late February. Today we can see large sections of ice that will soon be calving, but what this means will need to be matched to the other measurements we are collecting before we know the full set of changes in Getz.

IceBridge: Since 2009, the NASA IceBridge project has brought together science teams to monitor and measure each of the ice features in order to improve our understanding of changes in the climate system and our models. Lamont-Doherty, under lead scientists Jim Cochran and Kirsty Tinto, has led up the gravity and magnetics measurements for these campaigns. This season alone, the project has logged 195 hours of flight time to date, and flown an equivalent of a third of the way to the moon.

Save

Save

Save

Save

Save

Save

Year by Year, Line by Line, We Build an Image of Getz Ice Shelf

Tracking Antarctica's Ice Shelves - Sun, 11/06/2016 - 16:16
Grease Ice

Newly formed sea ice called “grease ice” looks like thin layers of mica along the front of the Getz Ice Shelf, Antarctica. Photo: M. Turrin

Antarctic ice appears in a range of types and sizes, from the newly formed skim of ice on the ocean called grease ice (above), to the older meter thick layers of sea ice, to chunks of icebergs, floating reaches of ice shelves, and finally the massive land based Antarctic ice sheet. Each part of this ice inventory has a unique role in the larger climate system, but they also work together. As part of this year’s IceBridge Antarctic flight campaign, we are focused largely on the coastline to build a better understanding of the interaction of these different pieces in the ice system. This understanding is central to improving our climate models.

Break in Ice Shelf

Evidence of a break along the front edge of Getz Ice Shelf, Antartica. In the foreground a mixture of newly forming sea ice has mixed with icebergs to form what is called “brash ice.” Photo: M. Turrin

The focus today is on Getz ice shelf. Ice shelves form when ice flows off the land into the surrounding ocean, forming a thick apron of attached, but floating ice. The Getz shelf extends out several miles from where the glacier empties into the ocean. The shelves are deep floating blocks of ice ~ a km thick where they first meet the ocean and thinned to several hundred meters thick at their front edge. They are critical for the future stability of the Antarctic ice sheet as they provide a barrier that holds back the continental ice sheet, braking its flow from land into the ocean.

Image noting the location of some of the larger ice shelves around Antarctica (Image T. Scambos NSIDC)

Image noting the location and size of  a dozen or so of the larger ice shelves around Antarctica. Image: T. Scambos NSIDC

In all ~ 45 ice shelves adorn almost half the Antarctica coastline, and represent an area of ~1.5 million km², close to 10 percent of the total ice that covers Antarctica. Ten of these are considered major shelves, with the largest two nestled in the junctures where East and West Antarctic meet, filling in the space with California-sized blocks of ice: the Ross Ice Shelf (at 472,960 km²), where Lamont-Doherty currently has another Antarctic research project called Rosetta running, and the Filchner-Ronne (422,420 km²) across from it. Many of the shelves are smaller, yet each serves a valuable role in Antarctic ice stability, and thus they are a prime focus for examining change in Antarctica.

Tabular icebergs after separating fro the ice shelf line up along the front of Getz before moving out into the ocean. (Photo M. Turrin)

Large tabular icebergs after separating from the ice shelf line up along the front of Getz before moving out into the ocean. Photo: M. Turrin

Changes in Antarctic ice have been dominated by the interaction of the ice and the ocean, and because ice shelves extend out into the water, they are vulnerable to melt from the warmer ocean water. Melt can affect them in two ways, through thinning along their length and through causing a retreat of the “grounding line.”  The grounding line is the critical spot where the ice goes from being frozen all the way to the ocean floor (or bed) to where it begins to float in the ocean. The grounding line retreat results from warm water melting the ice back from its frozen base. Tracking any changes to the location of the grounding line tells us a lot about the vulnerability of the ice shelf and is critical to setting models.

Ice shelves sit primarily below the ocean surface. Getz measures close to 200 ft. at the front but with another 1000 ft. below the surface. The rich blue color along the front edge is from that deep reaching ice front. (Photo M. Turrin)

Ice shelves sit primarily below the ocean surface. Getz measures close to 200 ft. elevation above the ocean at the front, but has another 1000 ft. of ice below the surface. The rich blue color along the front edge is from that deep reaching ice front. Photo: M. Turrin

Getz ice shelf is our furthest flight mission of the campaign at close to 12 hours of flying, and it is our fifth mission this week, with each one clocking 11 plus hours of flight with prep and wrap-up added on either end. It could feel a bit like a rerun of the same movie, but it never does, and the wear of the long days doesn’t appear to show on the team. The purpose of today is to continue mapping the sub ice-shelf bathymetry using our gravimeter, as well as the ice surface and bedrock upstream of the grounding line using laser and radar. We need a complete look at the grounding line and the bed under the ice shelf, where warm ocean water can move in and circulate under the ice, in order to improve our models. Gravity is critical for uncovering the surface depths and contours under the ice shelves, as none of the other instruments on board are able to collect data through the water that lies under the shelf.

Mountain Protrusion

A set of mountains protrudes up through the ice at the west end of the survey line along the edge of the Getz Ice Shelf. Photo: M. Turrin

Because of the distance to Getz from our daily starting point in Chile, we have been building a set of data over a series of years, line by line. Each year we collect a repeat track and a new track. We know Getz has changed. Eighteen months ago in March 2015, a NASA image from space captured a Manhattan-sized iceberg (17 miles long) breaking off of Getz Ice Shelf. This break appears to have occurred at the end of the last austral summer in late February. Today we can see large sections of ice that will soon be calving, but what this means will need to be matched to the other measurements we are collecting before we know the full set of changes in Getz.

IceBridge: Since 2009, the NASA IceBridge project has brought together science teams to monitor and measure each of the ice features in order to improve our understanding of changes in the climate system and our models. Lamont-Doherty, under lead scientists Jim Cochran and Kirsty Tinto, has led up the gravity and magnetics measurements for these campaigns. This season alone, the project has logged 195 hours of flight time to date, and flown an equivalent of a third of the way to the moon.

Save

Save

Save

Save

Climate and Homo Sapiens Migration during the Last Ice Age - The John Batchelor Show

Featured News - Fri, 11/04/2016 - 07:19
John Batchelor talks with Lamont's Peter de Menocal about the timing of when Homo sapiens began migrating from Africa.

Sand Demand at the Center of Beach Replenishment Planning - WorkBoat

Featured News - Thu, 11/03/2016 - 12:00
The federal Bureau of Ocean Energy Management is compiling and updating maps and databases about offshore sediment resources from Maine to Florida for use in post-hurricane beach replenishment. The cores from those offshore deposits are now being kept at the Lamont Core Repository.

Where Science Lives: Carlos Becerril - New York Academy of Sciences

Featured News - Wed, 11/02/2016 - 08:42
Lamont's Carlos Becerril talks with the New York Academy of Sciences about his team's work building ocean bottom seismometers as part of the Ocean Bottom Seismograph Instrument Pool (OBSIP).

Thousands Displaced After Italy Earthquake - CBS News

Featured News - Mon, 10/31/2016 - 15:29
A magnitude 6.6 earthquake struck Italy on Oct. 30 following two smaller earthquakes a few days earlier and a devastating earthquake there in August. “Probably it's every hundred years you get a repeat of a series of earthquakes,” Lamont's Michael Steckler told CBS News.

Water Challenges of Megacities - Eos

Featured News - Wed, 10/26/2016 - 12:00
Looking ahead to looming water quantity shortfalls, Lamont's Yan Zheng argues that using reclaimed water for managed aquifer recharge needs to play a larger role in China’s water management strategies.

Climate Change Is Fueling America’s Forest Fires - Huffington Post

Featured News - Thu, 10/20/2016 - 12:00
The wildfires that raged through the Western United States this year claimed lives, destroyed hundreds of homes and cost taxpayers millions of dollars. A new study from Columbia University's Park Williams has found that climate change has been exacerbating wildfires in the Western United States for decades.

Pages

 

Subscribe to Lamont-Doherty Earth Observatory aggregator