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Buried in Muck, Clues to Future NYC Drought - Mother Jones

Featured News - Fri, 08/09/2013 - 11:00
Outside New York, Lamont-Doherty scientist Dorothy Peteet thinks muddy marshes hold the secrets of future climate change.

Ice Ages: Why North America Is Key to Their Coming and Going - Christian Science Monitor

Featured News - Wed, 08/07/2013 - 11:00
Scientists have long tried to figure out what causes the ebb and flow of ice ages. New data suggests a novel explanation for why the mile-thick blankets of ice retreat so quickly: They become too heavy, as Lamont's Maureen Raymo explains.

Montreal Protocol Is a Rare Gift That Keeps Giving - Motherboard

Featured News - Mon, 08/05/2013 - 11:00
Coverage of Journal of Climate study by former Lamont graduate student Yutian Wu, Richard Seager and Lorenzo Polvani.

Imaging beneath the southernmost volcanoes in the East Africa Rift

The last time we visited the southern part of the East Africa Rift, we were responding to an unusual series of earthquakes in December 2009 that shook northern Malawi. The faults responsible for these events had not produced any earthquakes historically, and thus caught everyone by surprise. The unexpected occurrence of earthquakes on these faults highlights our poor overall understanding of how the African continent is slowly stretching and breaking apart.

This time, we return to this part of the rift system as a part of a more comprehensive effort to understand the underpinnings of this continental rift using a spectrum of geological and geophysical tools and involving a big international team of scientists from the U.S., Tanzania and Malawi. In the coming three weeks, we plan to deploy ~15 seismometers in southwest Tanzania around the Rungwe volcanic province, the southernmost volcanism in the East Africa Rift system. These stations will record small local earthquakes associated with active shifting of faults and moving of magmas at depth. They will also record distant earthquakes that can be used to create images of structures beneath Earth’s surface and map the faults and magmas.

Rungwe seismic deployment

Map showing elevation and lake depth, locations of volcanoes (red triangles, from Smithsonian Global Volcanism Program), major faults (black lines) with planned locations for seismometers. We plan to deploy 15 stations (light blue circles) in the next three weeks around the Rungwe volcanic province. Dark blue circles show tentative locations of stations to be deployed in the summer of 2014.

 

Only 144 Miles, Yet Worlds Apart

Peering Through Polar Ice - Sun, 08/04/2013 - 11:25
The icepod team at Raven Camp, Greenland Icesheet. (Photo M. Turrin)

The IcePod team at Raven Camp, Greenland ice sheet. Photo: 2nd Lt. C. Martin, NYANG

144 miles separates Kangerlussuaq from Raven Camp. Not far really, just 144 miles – like traveling from the southern tip of New York City up to Albany. Flying at 270 knots we can be there in about half an hour, no time at all, and yet to the casual observer they seem worlds apart.

Kangerlussuaq Greenland on the Sondrestrom Fjord. (Photo M. Turrin)

Kangerlussuaq Greenland on the Sondrestrom Fjord. Photo: M. Turrin

Kanger sits nestled in the arm of Sondrestrom Fjord, where over the years Russell Glacier has found the soft belly in the rock base, wearing the surface down flat and pushing the rock flour out to sea. Currently the tip of Russell Glacier is a full 20 kms (14 mi) up the fjord. In the summer months, as research teams move through the village, glacial meltwater fills the carved channel that borders the small town.

Meltwater Rushing Behind Kangerlussuaq, Greenland

“Summer meltwater from Russell Glacier rushes around the edge of Kangerlussuaq.”

Although modest in size by our standards, Kangerlussuaq is a transportation hub for Greenland, and has a steady year-round population of ~500 residents.

Population at Raven Camp. (Photo M. Wolovick)

Raven Camp population posting -  “Pop. 2.” Photo: M. Wolovick

Raven Camp sits high up on the Greenland Ice Sheet on a frozen bed of ice, almost 2 kms thick (~1 mi) and millions of years in the making. At almost 7,000 feet of elevation, no seasonal change will bring a rushing river or a population to match that of Kangerlussuaq, but summer research does bring an influx of summer scientists, swelling the population beyond the posted total of 2. With a handful of tents and collapsible housing structures, Raven Camp is a summer town.”

Icepod collecting data as part of the Raven Camp grid. (Photo M. Turrin)

IcePod tucked up for transit to Raven Camp, where it will be lowered to complete the survey grid over the ice landing strip. Photo: M. Turrin

Today we fly to Raven Camp to complete a survey grid over the ice landing strip. A year ago the camp staff detected several cracks (crevasses) in the ice running perpendicular to the airstrip. Crevasses are to be expected around the edges of an ice sheet, where the ice is faster flowing, however, at this elevation and this far inland it is more unusual. Published data for ice movement in this area shows at the base the ice is moving about 2.5 cm a day, while at the surface ice is moving closer to 7 cm a day. It is no surprise that the ice at the base moves more slowly, a result of the increased friction at the bed causing the ice to stick and slow.

Dye 2 facility at the Raven Camp established during the cold war as one of four sites in Greenland that were part of the U. S. Distant Early Warning Line, a system of radar stations to warn of incoming Soviet bombers. (Photo M. Wolovick)

Dye 2 facility at the Raven Camp established during the cold war as one of four sites in Greenland that were part of the U. S. Distant Early Warning Line, a system of radar stations to warn of incoming Soviet bombers. Photo: M. Wolovick

Currently measuring only 10 cms across, it certainly doesn’t seem that this could cause much trouble. But if the crevasses are deep and continue to widen, they will threaten the landing strip. A team of scientists has been collecting measurements on the ground to see if these rates are changing (2013 polarfield blog1); our job is to survey the area with our instruments. The Shallow Ice Radar and the infrared camera collect the depth of the cracks and the temperature differences as the cracks move deeper into the ice. Pulling all this data together will help us understand what is happening to the ice in this area.

The Shallow Ice Radar collects images through the upper layer of ice. (Photo M. Turrin)

The Shallow Ice Radar collects images through the upper layer of ice. Photo: M. Turrin

Our flight grid will be flown low, at 1,000 ft. above the ice surface, one third our normal survey elevation. Two East/West lines are flown perpendicular to the landing strip at 600 meters apart. Then three tie lines are flown parallel to the runway at 100 meters apart.

 

 

 

 

Once the grid is complete, we land on the airstrip, testing the seal on the pod door and collecting some camp cargo. The landing is smooth.

Nick Frearson, lead engineer on the Icepod project prepares to check the pod for snow after the ice runway landing at Raven Camp. (Photo M. Turrin)

Nick Frearson, lead engineer on the IcePod project, prepares to check the pod for snow after the landing on the ice runway at Raven Camp. Photo: M. Turrin

Temperatures today at Raven are a warm 1°C. The snow has lost some of the crispness we had experienced when we had landed in April to install a GPS on the ice. The pod is inspected. The camp looks all but abandoned, yet a snow vehicle appears with cargo that is stashed and secured for transit. While the cargo is loaded, we snap a quick IcePod team photo.

Cargo is loaded into the back of the LC130 at Raven Camp. The aircraft is not turn off during ice landing - all loading is done quickly. (Photo M. Turrin)

Cargo is loaded into the back of the LC130 at Raven Camp. The aircraft is not turned off during ice landing — all loading is timed with the ground for a quick exchange.(Photo: M. Turrin

The new eight-bladed propellers on Skier 92 do their job and the take-off is smooth for our return to Kangerlussuaq, just 144 miles, 30 minutes of transit, and yet seemingly worlds apart.

1 For more on the science being collected on the ground on ice movement: http://www.polarfield.com/blog/tag/greenland-ice-cap/

For more on IcePod: http://www.ldeo.columbia.edu

 

 

 

 

 

 

 

 

 

 

Greenhouse Gas May Find Home Underground - (Bergen, NJ) Record

Featured News - Fri, 08/02/2013 - 12:42
Lamont-Doherty geologist Paul Olsen comments on a $13 million study of the Newark Basin's carbon-storage potential funded by the U.S. Department of Energy.

IcePod Flies High in Arctic Test - Poughkeepsie Journal

Featured News - Fri, 08/02/2013 - 12:28
More coverage on the Lamont IcePod team's work in Greenland from the Poughkeepsie Journal's John Ferro.

Is Fracking in New Jersey's Future? - (Bergen, NJ) Record

Featured News - Fri, 08/02/2013 - 11:36
Lamont-Doherty geologist Paul Olsen comments on the Newark Basin's potential natural gas reserves.

How a Fickle Climate Made Us Human - Science

Featured News - Fri, 08/02/2013 - 11:00
Lamont-Doherty scientist Peter deMenocal comments on ongoing research linking Africa's changing climate to human evolution.

Out of the Kenyan Mud, an Ancient Climate Record - Science

Featured News - Fri, 08/02/2013 - 11:00
Lamont-Doherty scientist Peter deMenocal discusses research linking climate change in East Africa to human evolution.

Magma Can Take 'Highway from Hell' to Fuel Volcanic Eruptions - Los Angeles Times

Featured News - Thu, 08/01/2013 - 12:48
Coverage of study in Nature by Lamont's Philipp Ruprecht and Terry Plank.

Bizarre Crystals Reveal Underground Magma 'Highway' - Christian Science Monitor

Featured News - Thu, 08/01/2013 - 11:00
Coverage of Philipp Ruprecht and Terry Plank's study in Nature.

The Langseth cruise is winding down!

Mapping the Galicia Rift off Spain - Thu, 08/01/2013 - 09:32

The Langseth Galicia 3D seismic cruise is winding down. By tomorrow we will be back at the dock in Vigo. Like most seagoing science, we will miss the ship experience, we will miss the new colleagues we have met, we will look forward to getting back on shore, and for many of us the awesome multi-year task of processing, interpreting, and publishing the boatload of data we have acquired.

This is an example of the data we have collected. Right is to the East and left is to the West. This is a cross section of the Earth about 65 km long. The blue is water. The water depth here is about 5 km. The red and gray colors are a cross section of the rocks below the water. The flat layers are sedimentary rocks. The lumpy bumps (that is a technical term!) consist of blocks of continental crust and of the mantle.
We thank the Langseth’s Captain and crew for making this possible! These are men and women who live on the sea, and who share their ocean world with us for a month or two. Every now and then, when you can walk 100 meters in a straight line, ask yourself, “Where is the Langseth now, and who is steering the ship, or keeping the engines running, or keeping the deck ship-shape, or providing good food, or every other important task on the ship?” Under your breath say thank you for the experience you had on Langseth.
We thank Robert and his technical team. They worked tirelessly to assemble the 24 km of hydrophone streamer that hears the reflections from the Earth, the 40 or so airguns that make the booms, and all the rigging it takes to tow them spread out behind the ship over 600 meters wide and 7000 meters long. That was just the start. Then they operated the electronic equipment that received the seismic data and recorded it for the scientists. Without them we could not do the science we love.
Thank you to the Science Party. We had a total of 20 scientists, including undergraduate students, graduate students, post-docs, researchers, and professors. On Leg 1 we had 14 scientists and on Leg 2 we had 10 scientists. Four scientists weathered both legs. Six joined us for Leg 2. I am very grateful for all your efforts on behalf of the Galicia 3D science. I hope that you learned a lot, had a good time, and met other scientists for the first time. I suspect that we will meet one another many times in the future.I look forward to that!


This is the Technical team and the Science team for Langseth Leg 2.
I want to thank the Protected Species Observers for sailing with us. They spent countless hours in the observing tower, high above any other part of the ship. They have sighted hundreds of whales, but most did not come close to the ship. It is windy and cold up there, but their role is important for making sure that collecting our scientific data does not interfere with the creatures who call the ocean home.
Thank you for sending your loved ones off on the Langseth. I can certify that they now know how to do their own laundry and to clean up their cabin before they leave the ship. During the weekly emergency drill, they run quickly up to the muster station on deck and put on safety gear. I recommend that you continue to enforce these behaviors ruthlessly! They will forget them if you let them slack-off. On the other hand, they did not have to cook their own food, or wash and dry their dishes. You will still have to work on these behaviors!
As I write this from the Langseth, we should remember that the Galicia 3D experiment goes on. Our colleagues from GEOMAR and University of Southampton will be on the FS Poseidon from 25 August to 10 September. They will be recovering the 78 Ocean Bottom Seismometers that are still on the bottom (on purpose!). They have been recording approximately 150,000 airgun array shots fired by the Langseth. I know what you are thinking. “How many total recordings of shots are recorded in all the OBS’s?” That would be about 11.7 million shot recordings. This will keep the OBS scientists busy for a while!
I particularly want to thank James Gibson for creating this blog. It has reached out to our friends and to strangers. We plan to keep the blog alive. This project will continue for years.

Best regards,Dale SawyerRice University

Russell Glacier Provides Firsthand View of Greenland's Ice Melt - Poughkeepsie Journal

Featured News - Wed, 07/31/2013 - 15:00
The Poughkeepsie Journal's John Ferro reports from Greenland's Russell Glacier where the Lamont IcePod team is performing test flights.

Magma Can Speed to the Surface, Powering Volcanoes - ScienceNews

Featured News - Wed, 07/31/2013 - 14:36
Coverage of volcano study in Nature by Lamont's Philipp Ruprecht and Terry Plank.

Volcanic Magma On the Highway from Hell - Discovery News

Featured News - Wed, 07/31/2013 - 14:34
Coverage of volcano study in Nature by Lamont's Philipp Ruprecht and Terry Plank.

'Highway from Hell' Fed Deadly Volcano - LiveScience

Featured News - Wed, 07/31/2013 - 14:32
Molten magma from Earth's hellishly hot mantle can punch through miles of the crust in just a few months. Coverage of Nature study by Lamont's Philipp Ruprecht and Terry Plank.

Behind the scenes of the ship

Mapping the Galicia Rift off Spain - Wed, 07/31/2013 - 12:26

This week we have been exploring all the parts of the ship we have not yet discovered and were lucky enough to get shown around the engine room and the bridge. It is evident that each area of a ship (bridge, engines, science etc.) has a group of people doing those specific jobs and that the combination of everyone doing their part keeps everything running smoothly; like cogs in a massive machine. 
The engine room control panel. With that many buttons no wonder it takes so much training to work in the engine room!The engine room is located in the hull of the ship and is the biggest room on board by far, taking up about 2/3rds of the bottom deck. This is obviously a very important part of the ship because without it we would not be moving anywhere! The Langseth has 2 engines leading to 2 propellers and also 1 bow-thruster. There are so many different bits of machinery down there that it can take 4 years of studying to be qualified to work in the engine room. It is very loud and warm but surprisingly clean and tidy. There are also 2 compressors which are used to pressurise the air for the air guns that we tow. 
One of the very noisy compressors. It is hard to portray the size of these in a photo, they are huge!The heat from the engines is used to produce all the hot water for the ship and the engine room also has machines for desalinising our water. Fuel usage is constantly monitored and fuel moved between all the many tanks spread around the ship to ensure even weight distribution. Even though we only travel at about 4 knots whilst acquiring data we burn between 5000-6000 Gallons of fuel a day due to the massive load of the equipment we are towing behind us.
One of the two enginesThe bridge sits at the front of the ship on top of the main living quarters. From here it seems as if practically everything can be controlled. They drive the ship when we are not driving from the main science lab during acquisition, control the speed, can manage the safety aspects including all alarms and watertight doors and keep a look out for anything floating past that might get caught up in our seismic gear (so far buoys and pallets have been sighted). One very important job of the bridge is to communicate with other nearby vessels. Nobody would expect us to be towing 6km of streamers so we have to make sure we let other ships know with enough time to arrange safe passing, therefore avoiding collisions.
This is the main control panel in the bridge. There are screens for  navigation and
radar as well as all the speed controls. There are two smaller control panels
on the port and starboard sides of the bridge for work that
involves careful maneuvering e.g. picking up OBS's. The last seismic line is just being finished right now and then we can get ready to begin equipment recovery. It is about 40 hours until we are back on dry land again! 
Tessa GregoryUniversity of Southampton  

Binning is the name of the game

Mapping the Galicia Rift off Spain - Wed, 07/31/2013 - 03:44
As we come to the end of our cruise I thought that now would be a good time to talk about the way in which both seismic and multi-beam sonar data are quantified (basically nerd out). In both cases we "bin" the data into grid cells, which are predefined based on the resolution that we expect to achieve given the ideal data density of individual cells within the grid. 

A screen capture from the multi-beam sonar Seafloor Information System (SIS).
The image on the left shows swath coverage. The image on the right shows an active ping through the water column.Multi-beam sonar (swath seafloor mapping) data are collected, gridded (binned) to the predefined cell size, and output in two flavors. Bathymetric grids, which are essentially 3D topographic maps, and Backscatter grids, which display the reflectivity of the seafloor. The reflectivity varies due to both incidence angle of the respective beams and the density of the surface (e.g. hard rock, sediment etc). As the ship moves along at a given velocity, the multi-beam sonar sends a "ping" from the transducers (transmitters) to the seafloor and then waits until the receipt of the last return to ping again. The ping rate (Hz or 1/seconds) is a function of the depth of the ocean as well as the sound speed through water (XBT's are useful!). The swath width also scales as a function of depth. Our average depth is ~4800m (2.98 miles), which allows for an achievable swath width of ~20km (12.43 miles!).
Swath coverage display of the backscatter (reflectivity of the seafloor) collected across a swath.In order to gain insight on the density of the multi-channel seismic (MCS) data that we are collecting we use the Spectra software package. Spectra tracks the position of the ship, streamers, and air guns in real time using GPS and an acoustic network, and then bins the data accordingly within the predefined grid. The goal is to get an equal amount of seismic traces (reflected seismic waves) in each bin. The traces can then be stacked (combined), which increases the signal to noise ratio. Stacked traces within a bin are called "fold" and ideally represent traces from all offsets along the streamer in respect to the source.

A screen capture of the Spectra display. The image on the left shows active binning of the MCS data.
The image on the right shows the bins being infilled (filling holes).We are getting to the end of the "No Mores," which means we are finished on Friday!! Stay tuned for a word from our Chief Scientist along with a look at the MCS data (and our cruise pic). 
James GibsonLamont-Doherty

Gone Fishing…Took IcePod!

Peering Through Polar Ice - Tue, 07/30/2013 - 21:19

 

Surface meltwater lake.

Ice sheet surface meltwater lake. (Photo: M. Turrin)

When the New York Air National Guard travels to Kangerlussuaq, they toss in a few fishing poles with the baggage for whatever few hours of free time might be available. A favored pastime for this location’s summer assignments means the local lakes are well known by the crew, so when we sat down to map out the flight plan, a request for locating lakes met with an easy nod. No problem at all. It took only seconds to register that our definition of lakes might differ from theirs.

Icepod 'lakes' are actually surface meltwater pools on the icesheet. (photo M. Turrin)

IcePod ‘lakes’ are actually surface meltwater pools on the ice sheet. Photo: M. Turrin

We are interested in lakes atop the ice sheet surface, places where the ice sheet melt is puddled into lakes of various sizes. It is in locations like these lakes where water, with its darker color, absorbs more heat from the sun than the surrounding white ice surface. This process can contribute to more melt, and in some instances the water finds a weak “joint” in the ice and drains right down to the bottom. Both the extent of the ponding and this process are of interest to the science community in better understanding the ice sheet.

The guard is quick to assure us, no problem, these too can be located!

Chris Zappa,oceanographer and project optics expert, peers out the window of the LC130 aircraft.

Chris Zappa, oceanographer and project optics expert, peers out the window of the LC130 aircraft. Photo: R. Bell

It was an “optics day,” where our focus is on the cameras in IcePod. Using both our Bobcat (visible wavelength) and our (IR) infrared cameras, we will image surface lakes and the meandering meltwater channels on the ice sheet surface, and then fly over a few of the southwest fjords to image meltwater as it plumes at the calving edge of the ice sheet. This is a day that Chris Zappa, our resident oceanographer and optics expert, has been waiting patiently for. The weather is perfect, the sky crystal clear, and the instruments are humming. We are ready to go.

Surface feature on the ice that appears to be a meltwater channel that has been covered over by blown snow. (Photo M. Turrin)

Surface feature on the ice that appears to be a meltwater channel that has been covered over by blown snow. Photo: M. Turrin

The surface of the ice sheet barely resembles our April visit. Large lakes, some a mile across, are printed along the ice sheet surface, as if a skipping stone has skimmed along the surface leaving pockets of water in its wake.

Icepod Visible wavelength camera captures the meltwater lake as we fly overhead. (Photo M. Turrin)

IcePod visible wavelength camera captures the meltwater lake as we fly overhead. Photo: M. Turrin

These ice surface lakes are viewed more cautiously than our lakes back home, as they pose a threat of suddenly emptying through a “moulin” or drainage tube. Moulins transfer water from the surface to the bottom of the ice sheet in short order, circumventing a process that could otherwise take many thousands of years. Cutting across the surface in various patterns, meandering channels carry the melting surface water into these catchment pools. On the ice sheet these channels are the equivalent of streams from our home communities. Back home they collect runoff and drain into freshwater lakes. Here they serve the same function but are more striking, as there are no plants to screen them.

The tip of the icepod can be seen as we move over this meandering meltwater channel on the icesheet. (Photo M. Turrin)

The tip of the IcePod can be seen as we move over this meandering meltwater channel on the ice sheet. We imaged some of these channels in April. From the plane their frozen surfaces had appeared flat and greytone. Now they are deeply cut and etched, filled with a sparkling aquamarine coloring as the ice has warmed, experiencing some summer melt. Photo: M. Turrin

Icepod images over the heavily crevassed surface of the icesheet. (Photo M. Turrin)

A dense pattern of crevasses cuts across the ice surface, darkened with scattered dust and debris along the edges of the ice sheet, clearing to toothpaste white as we move to the interior. IcePod captures images as it moves over the heavily crevassed surface of the ice sheet. (Photo M. Turrin)

The cameras work furiously. The Bobcat, is a 29-megapixel camera. The IR samples at 100 frames per second. Both cameras collect a staggering 60 gigabytes a second. Images play across the screen showing the temperature contrasts as we move over the surface features.

At the calving front of the glacier meltwater and sediment plumes are among the processes the icepod cameras are capturing. (Photo M. Turrin)

At the calving front of the glacier meltwater and sediment plumes are among the processes the IcePod cameras are capturing. Photo: M. Turrin

We move from the ice sheet to the coastline, where rugged mountains circle Greenland’s perimeter like a crown. Fjords cut through in many areas, allowing deeply stacked ice in the interior to move off the land. Today we are flying down small “arms” of Godthaab Fjord with a focus on their leading edges, where the ice meets the Atlantic water. We are interested in how the IR camera can be used to track thermal plumes at the interface of the cold glacier meltwater and the warmer ocean water. Combining both the Bobcat and the IR cameras allows sediment plumes to be tracked moving through the fjord. Sediment should warm faster than the surrounding water, and may be transferring more heat into the system. Both will tell us about circulation, mixing and transit of the glacial meltwater systems.

Small fishing village along the edge of a fjord in southwestern Greenland. (Photo M. Turrin)

Small fishing village along the edge of a fjord in southwestern Greenland. Photo: M. Turrin

Flying back down the fjord we pass over a small fishing town perched on the edge of the water. There is no apparent movement below. Perhaps they have gone fishing?

 For more about the IcePod project: http://www.ldeo.columbia.edu/icepod

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