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What’s Making West Antarctica Melt?

 Debra Tillinger.

Icebergs are a sign of warming in West Antarctica. Credit: Debra Tillinger.

The view from the Palmer is so blindingly white today that the eye cannot tell where the ice ends and the clouds begin. In this unusually icy Antarctic summer, it seems strange to contemplate melting ice. But glaciers, here and in Greenland, are melting faster than they are growing. We know that ice sheets have been around for thousands of years, but certain areas are currently melting and breaking off into the sea at rates that far exceed their growth. The breakup of 3,320 square kilometers (1,282 square miles) Larsen B ice shelf in 2002 was only the most dramatic example.

It is clear that we are losing ice faster than we have since reliable observations began. But those observations have only been made since the advent of satellites in the 1970s. How can we resolve the difference between the rates of ice sheet destruction and their long history on earth?

There are three hypotheses that I’m familiar with, but you are welcome to leave additional possibilities in the comments. The first is that global climate change is responsible. This makes intuitive sense, as we associate warmer temperatures with melting. But air temperatures, at least, are so far below freezing in most of Antarctica that raising them a few degrees will not lead to melting. On the other hand, glacial dynamics are not well understood, and temperatures in the water underneath ice sheets are hard to measure and could have a large effect.

Another possibility is that ice sheets are still responding to the last ice age. They could still be reaching equilibrium with our modern, pre-industrial climate. There is evidence that the increase in sea level, which began as the ice age ended, has slowed considerably in the last seven thousand years but is not quite over.

A third alternative is that short-term ice sheet variability is simply much larger than long-term variability. There is limited evidence from western Antarctica that glaciers can flow quickly for years and then stop abruptly.

The difficulty now is that we simply don’t have enough data to evaluate these hypotheses. That’s why the Nathaniel B. Palmer is trying to push through the seemingly impenetrable ice to reach the Larsen area. If we can get there and examine the local glacial history of the area, we may be able to place the Larsen breakup in historical context and understand what it means for the rest of the world and for the future.

Thanks to Greg Balco from the Berkeley Geochronology Center for his explanation of glacial geology.

Rough seas bring unexpected rewards

 Bruce Huber

Blocked by sea ice in Prince Gustav Channel. Credit: Bruce Huber

Working in Antarctica is always a challenge but this trip has had more than the usual setbacks. After working feverishly in Punta Arenas to prepare our ship, we had to wait two days for some essential cargo to arrive. Not long after pushing off, we encountered rough weather in the Drake Passage, a region notorious for unkind seas. The ship pitched and heaved, but the storm was brief, and we sailed out of the weather after one day.

Our planned route to the Larsen B embayment took us around the tip of the peninsula to the eastern side and south through Prince Gustav Channel, where we were stopped by an impressive field of sea ice. The sea ice around Antarctica typically retreats in austral summer—December through February—and grows again in early April. We had hoped the sea ice would retreat enough to allow us easy passage to Larsen B. This year, though, the ice in the Weddell Sea had not retreated very much, forcing us to come up with a back-up plan.

We had planned to fly over several glaciers in a helicopter, to install instruments that would automatically record ice movement and weather. Some of the sites happened to be accessible from the western side of the peninsula, where there is no sea, so we decided to sail there and wait for the ice to melt on the eastern side. We arrived on Jan. 14, but bad weather has prevented us from taking the helicopter up.

While waiting for better conditions, we are taking measurements in several fjords along the western coast. We are now in the Gerlache Strait, a popular site for cruise ships because of its spectacular scenery and whale watching. So far we’ve seen humpback and minke whales feeding in the calm iceberg-studded waters.

Stopped by sea ice, we sailed from the west coast of the peninsula to the east coast. The red dot marks our location as of Jan. 22.

Stopped by sea ice, we sailed from the east coast of the peninsula to the west. The red dot marks our location as of Jan. 22.

The setbacks have given us an unexpected opportunity to learn more about this fascinating part of the Antarctic Peninsula ecosystem. We will soon head back to the Larsen side to test the sea ice again, with our instruments ready to go.

Adelie penguins

 Caroline Lavoie

Bird watching. Credit: Caroline Lavoie

The nice folks up on the bridge always give us a call when they see wildlife. Then we all grab our cameras and rush out to our favorite spots to try and photograph whatever creatures have come to visit.

I’m no biologist, but seeing so many beautiful animals has made me curious. So I’ve been doing a little reading and I’d like to share with you what I’ve learned about some of our favorite visitors, the Adelie penguins. This photo of the Adelies was taken a few days ago by Caroline Lavoie.

Adelies are only 30 inches tall and weigh about 11 pounds. But millions of years ago, there were penguins that stood 5 feet tall and weighed 200 pounds! They’re not alive today, and I’m having trouble imagining them.

While many of us associate penguins with Antarctica, they’re actually spread all over the Southern Hemisphere, with a few living right on the equator. There are seventeen species of penguins, but only Adelies and emperor penguins live exclusively in Antarctica.

Girls on Ice

smgoi

While I’ve been staying on the ship, Erin Pettit has been flying off by helicopter to study glaciers. She has a really cool job, and I wish she would take me with her on some of her adventures. But it turns out that she wants to take you!

Erin runs a program called Girls on Ice. Every year since 1999, she takes 9 teenage girls to Mt. Baker in Washington State for 11 days. The program is FREE and applications are available now at http://girlsonice.org/apply. Those of you at DLMS are a little too young for the program, but I want you to start thinking about it now so that you’ll be all set to apply in a few years. And tell your friends!

This isn’t just about getting to visit somewhere new and beautiful with an awesome scientist. You’ll learn how to study glaciers, how to climb glaciers, how to stay safe on glaciers, and you’ll even work with an artist to learn how to draw glaciers. And don’t worry: you don’t need any experience, you don’t need perfect grades, and you don’t even need to be sure that you want to be a scientist. You just need to be interested in learning more about the earth and in challenging yourself.

A Change in Plans

ship_in_iceIn 1914, Ernest Shackleton wrote “Pack-ice might be described as a gigantic  and interminable jigsaw-puzzle devised by nature.” Shackleton was a great Antarctic explorer. He wanted to be the first to cross the continent of Antarctica, but his expedition ran into unexpectedly icy conditions. He is famous now, not for achieving his goal, but for surviving the loss of his ship and keeping all of his men alive through terrible conditions.

I’ve been thinking about his story because we’re working in the same area that he sailed, and we also have an unusually icy year. But unlike Shackleton, we have helicopters, satellite pictures of the ice, and reliable communication with land. We’re also in a much bigger and safer ship!

I took that photo from the bridge of the ship (the bridge is like the cockpit of an airplane). You can see that the ship is entering the ice. We can break through the ice, but we can’t go all that quickly. We sent a helicopter to check on the ice ahead of us and determined that it gets thicker further south and we can’t get through. So we’ve done what Shackleton couldn’t: we turned around and we’ll be exploring the western side of the Antarctic peninsula instead of the eastern side.

In a few weeks, we’ll try again to reach our original goal on the eastern side of the peninsula. Until then, we’re going to do the best research that we can on the western side. We have a ship full of great scientists and equipment, so you can bet that we’re not going to waste our time complaining about what we can’t change. We’ve been working together to plan some cool projects on the ice-free western side. I’ll start gathering data tonight and should be able to post some of my results soon.

Scientists on Ice

iceshelf

I don’t want to give you the idea that science is all fun and games. We work hard! But I have to admit that today has been pretty spectacular. The morning was spent watching the helicopters take off and land for an ice reconnaissance mission. Since the ship is fully iced in, we got to go off ship and play in the snow!

When I took that photo, I was standing on 3 inches of snow over about 3 feet of ice over some 2000 feet of water. You can see the ship and the returning helicopter!

In the Q & A post, I showed a photo of an iceberg. That ice came from water vapor in the atmosphere which formed snow or rain and landed on an ice shelf or glacier. The ice then broke off into the ocean.

The ice under the snow in this picture is completely different. It came from the ocean! When seawater freezes, it forms sea ice that floats on the surface of the water. The ice crystals push the salt out in to little pockets between the crystals. Over time, the salt drains out leaving fresh ice behind. The ice we were on is called fast ice, because it is attached (“made fast” in sailing terms) to the ice shelf.

Hola, Amigos!

ted_scambosPeople are very friendly at sea. Still, Ted Scambos spends an awful lot of time talking about his amigos. But it turns out that these are no ordinary friends – they’re Automated Meteorology-Ice-Geophysics Observing Stations.

The area that we’ll be visiting used to be a huge ice shelf, called Larsen B. It collapsed 2002, losing 3320 square kilometers (1,282 square miles) of ice. One of the goals of this research cruise is to figure out how that happened and what it means for the rest of the area. Only a small piece of Larsen B, the Scar Inlet Shelf, remains.

Before this cruise, Ted and his team tested the hypothesis that when there is a lot of water sitting on an ice shelf, it works its way down into cracks in the ice and causes the ice shelf to break apart. Normally, the pressure of the ice is enough to keep small cracks from growing. But this time, there was so much water that the cracks were pushed all the way open and the ice sheet broke apart.

amigosHow did he test this hypothesis? With AMIGOS! AMIGOS are machines that keep track of their location, the temperature of the air around them, and the thickness of the ice underneath them. They even take photos and send all of this information back to Ted. Ted put AMIGOS out on icebergs and saw that there was a lot of melted water on the icebergs right before they came apart. Their temperature was near the freezing point of water, which is very warm for an iceberg. These results were consistent with the hypothesis that water on the ice causes them to break apart.

But to get stronger proof, Ted is putting newer, better AMIGOS on the Scar Inlet shelf to see exactly what happens. If the hypothesis is correct, they should see more and more melted water on the surface of the ice before it breaks apart. Here is a picture of an AMIGOS on an iceberg, and one of Ted working on a thermometer for one of the new AMIGOS. Just so you know, he isn’t only interested in how icebergs and ice shelves break apart. He’s also monitoring what happens to glaciers after the ice shelves around them are gone, but we’ll cover that in another post.

(Photo originally published in Journal of Glaciology, reproduced with permission of the author)

Commenter Q & A

qaScience is just starting to get underway, so I thought this would be a good time to respond to some commenter questions. Just so you know, I’m doing this all by email, not internet, so I can’t reply in-line to your comments.

Richard: What is the break down on crew versus scientists on board?

The breakdown is actually between science, Raytheon, and Edison Chouest Offshore (ECO). ECO is responsible for running the ship and Raytheon is responsible for assisting science in labs and on the deck. We have 29 science, 14 Raytheon, and 23 ECO.

Nancy: What a wonderful, interesting set of pictures. They make me feel as if I am there with you on your ship. Did you have to do anything special to clean off the PVC pieces? Was it the first time you took samples of mud from the seafloor?

Thanks. We actually tried vacuuming each other to get the PVC off, but it didn’t work. The stuff finally came off when we walked down the very windy dock to the ship. And yes, this will be the first time that I help sample mud from the seafloor.

Erik: Good Day Mrs. T, I envy you, your cruise to Antarctica. I am a semi-retired yacht captain working ashore, so would love to follow your research. You said you are studying ocean currents. What is your background?

Your job sounds pretty cool too! I’m a doctoral candidate in ocean and climate physics. Most of my background is in the tropics, so this cold weather stuff is all new to me. I use equipment called Lowered Acoustic Doppler Current Profilers (LADCPs) to measure ocean velocity using sound. I’ll post more about the mechanics of that later on. Where did you sail as a yacht captain?

RW: Found you through the Happiness Project. I cannot believe you are going to Antarctica. When my children were just little we watched a documentary about such a vessel. And we have read a Madeleine L’Engle book about such a trip. I am super excited to have discovered your blog.

First, major thanks to the happiness project and Gretchen Rubin for promoting my blog. And thank you for reminding me about the Madeleine L’Engle book! I have a signed, hard cover copy of that book somewhere in my mother’s house and I highly recommend it.

RW: Hope the waters have settled for you. How long before you reach your destination?

Funny you should mention it. The waters have settled, but the pack ice is too thick to move through. We’re turning around and trying a different route to the Larsen B ice shelf. Our best guess is a few days, but we just don’t know.

In case you’re wondering, I took that photo yesterday from the bridge. A post all about icebergs will be coming soon!

East Coast Basalt and Carbon Sequestration - NPR Talk of the Nation

TRL Featured News - Fri, 01/08/2010 - 10:32
Basalt formations off the East Coast of the U.S. could suck up a billion tons of carbon dioxide, according to a new study. Paleontologist Paul Olsen, of Columbia University's Lamont-Doherty Earth Observatory, explains how to get the CO2 into the rocks, and why scientists believe it won't leak out.
Categories: TRL

The Transit Home

Mountains Under the Sea - Sat, 01/02/2010 - 18:29
The sun sets over the calm waters above the East Pacific Rise. We saw many such settings of the sun that were just as beautiful as this one. (Photo by Wanda Vargas)

The sun sets over the calm waters above the East Pacific Rise. We saw many such settings of the sun that were just as beautiful as this one. (Photo by Wanda Vargas)

We are in the midst of a four-day transit from our study site on the East Pacific Rise to the Atlantis’ next port of call in Costa Rica. All of the scientists aboard will depart for home from there, while many of the crew will stay on for another leg of the cruise. The transit thus far has been long and boring and slightly rough, but such transits give us plenty of time to write cruise reports, pack up our gear, and get ready for the next stage of our journey home.

There is also time to reflect on the past few days and weeks of work, which by and large have gone well (and have been anything but boring). Scott accomplished all of his scientific goals with his pressure measurements, Monika collected copious biological samples that will keep her group busy for some time, and as you know if you’ve been following along, the VentCam worked better than we could have hoped. Sometimes cruises do not go this well, so we have been sure to be thankful for our good fortunes. We are also indebted to the captain and crew of the Atlantis, and all the members of the Alvin group. Each of them deserves enormous credit for taking us safely to sea and helping us accomplish our scientific goals. Obviously we couldn’t have done it without them.

R/V Atlantis Wiper Leroy Walcott climbs out of the sub hoisting the flag of Barbados, which fittingly features a prominent trident symbol. Leroy is the first Barbadian to dive in Alvin. (Photo by Wanda Vargas)

R/V Atlantis Wiper Leroy Walcott climbs out of the sub hoisting the flag of Barbados, which fittingly features a prominent trident symbol. Leroy is the first Barbadian to dive in Alvin. (Photo by Wanda Vargas)

On a related note, one highlight worth mentioning occurred on the last dive of the cruise. A few days ago Scott held a drawing to give away the starboard observer position on the final dive — normally reserved for a scientist — to a member of the ship’s crew. The contest was open to any crew member who had not yet had a dive in Alvin. Most of the crew qualified for this contest, because the science party rarely has a slot available to give. Scott drew lots from a bag and the winner of the free trip to the bottom of the ocean was wiper Leroy Walcott from the engine department. He seemed more than enthused about the opportunity and word has it that he had a spectacular dive. He was also quite proud to be the first person from his home country of Barbados to dive in Alvin.

It has been an enjoyable and productive cruise that none of us will soon forget. But life on a research vessel can be difficult, and being away from friends and family is not always easy. So even though the forecast for New York has temperatures below freezing in the coming days, I am actually looking forward to being back home! See you all back in the cold cold city.

Christmas at Sea

Mountains Under the Sea - Sat, 12/26/2009 - 19:02
The white elephant gift table sitting just outside the sub hanger on Christmas. Some of the gifts were good. Some of them were not. Everyone had a fine time regardless.

The white elephant gift table sitting just outside the sub hanger on Christmas. Some of the gifts were good. Some of them were not. Everyone had a fine time regardless.

As you know yesterday was Christmas, and things are just a little bit different on such a holiday aboard a research vessel. Although the sub was in the water, many of the crew had the day off. As far as I can tell, most of them work around the clock, so such a rest was clearly in order. Dinner yesterday was also something special. Steward Carl Wood, Cook Mark Nossiter, and Mess Attendant Richard Barnes created a most delicious meal from scratch, including roast beef, turkey, stuffing, mashed potatoes, and all sorts of veggies and fixins. We ended the evening with a white elephant gift exchange on the fantail. Alvin looked on from inside the hanger while sporting a giant Santa hat made for the occasion by the group from Austria. A jolly good time was had by all.

But the highlight of my day was the return of the VentCam. Project engineer Carl Robinson dove in Alvin along with pilot Bruce Strickrott and geophysicist Milene Cormier of the University of Missouri. They carried a set of glass-ball floats down with them and when they reached the seafloor attached these floats to the VentCam tripod to send it toward the surface. About an hour and a half later, officers on the bridge spotted the yellow glass balls bobbing up and down, and maneuvered the ship in close. Bosun Wayne Bailey and members of his deck crew brought the instrument onboard without any shouting or hollering. Anyone who has ever done any oceanography knows that this is the ultimate sign of a well-executed recovery.

The VentCam on its way back on board the ship. The system performed as well as we could have hoped during it’s first seafloor deployment. (Photo by Wanda Vargas)

The VentCam on its way back on board the ship. The system performed as well as we could have hoped during it’s first seafloor deployment. (Photo by Wanda Vargas)

After an initial look at the video we collected, it looks like the deployment was a success. The camera’s light balancing routine worked very well, and all indications suggest that the flow rate analyses will work just fine. Carl and I will now begin the process of breaking down our gear and boxing it up for the shipment back home. I will also start planning for the next VentCam deployment, which might come as early as July. It’s never too early to start preparing for a cruise.

Meanwhile, Scott still has four dives left for making pressure measurements, so his work will continue. I’ll be in the ball once more tomorrow as a supporting member of his team, and I’m looking forward to another dive. So far Scott’s project has also gone well, and I hope to help continue the trend.

But Time Will Not

Mountains Under the Sea - Thu, 12/24/2009 - 11:50
Crew from the R/V Atlantis work during the dawn hours to move a wire spool from one winch to another. The domed satellite dish that provides our Internet connection towers over the scene.

Crew from the R/V Atlantis work during the dawn hours to move a wire spool from one winch to another. The domed satellite dish that provides our Internet connection towers over the scene.

Not everything on a research vessel always goes according to plan. Today we awoke to find out that during the night the primary CTD winch failed, leaving about 2000 meters of cable and a large instrument package over the side. Alvin cannot dive when we have a wire in the water, so this situation is going to delay today’s launch, and we may even need to scrap it altogether. Hopefully this won’t happen.

At night while Alvin is sleeping we use the CTD, which measures things like temperature, pressure and turbidity, to map the extent and intensity of hydrothermal venting above the ridge. Since Alvin can only dive during daylight hours, this is an excellent way to use the ship’s resources while we wait for the dawn. On rare occasions though there is an issue with the winch that can cause a delay.

Crew members from the engine room, the deck crew, mates, and the captain have been working through the night to move the spool from the faulty winch to a backup winch on the aft deck of the 02 level. These wire spools weigh many thousands of pounds, and it takes an extremely competent and experienced crew to change them out while the ship is rolling at sea. Thankfully, that is what we have on this ship. The crew is doing their best and doing it as fast as safely possible. Hopefully within another hour or two we’ll be winding in the CTD and preparing for a belated dive in the sub.

A Light in the Darkness

Mountains Under the Sea - Tue, 12/22/2009 - 23:43
The VentCam lights up a fresh lava pile within the axial summit trough of the East Pacific Rise.

The VentCam lights up a collapsed lava flow within the axial summit trough of the East Pacific Rise.

After a search during dive 4576, Scott finally found a suitable site for the VentCam deployment, and later that evening we launched the system overboard for its first trip to the seafloor. The next day, with the help of pilot Bruce Strickrott and pilot-in-training Anton Zafereo, we dove in Alvin to recover the device and position it at a black smoker vent called Bio9. It was a lovely sight to see it shining its light into the darkness as we approached. Intermittently flashing at programmed intervals, it looked like some kind of lunar lander examining a distant world. In a way, I suppose it was.

We used Alvin’s manipulator to carry the VentCam from the landing site over to Bio9, and after only about 30 minutes or so, Bruce had it all set up and ready to record video. If all goes according to plan, it will record 15 seconds of video at 75 frames per second every 10 minutes. I will be able to process this data using an image analysis technique that will tell me how fast the fluid is flowing out of the vent and how the flow is changing over time.

The VentCam positioned to collect data from the Bio9 vent at a depth of 2500 m below the surface of the ocean.

The VentCam positioned to collect data from the Bio9 vent at a depth of 2500 m below the surface of the ocean.

Once we iron out all the wrinkles, we hope to eventually build many of these devices and place them at many vents for long term deployments. By comparing changes in flow rate through different vents in response to events like earthquake swarms, we will begin to unravel more of the mystery of the subseafloor plumbing system, and better understand how heat and chemicals are transferred between Earth’s lithosphere and the overlying ocean. Such information will be critical as we work to understanding how mid-ocean ridge hydrothermal systems support deep sea ecosystems and how they fit into the global climate system. We’ll just take it one step at a time though.

And the Work Begins

Mountains Under the Sea - Fri, 12/18/2009 - 21:39
Nora Nikolov, Ingrid Kolar and Sabine Gollner, who work with Monika Bright at the University of Vienna, filter water that was collected on that day’s dive.

Nora Nikolov, Ingrid Kolar and Sabine Gollner, who work with Monika Bright at the University of Vienna, filter water that was collected on that day’s dive.

Monika Bright of the University of Vienna had the first dive of the expedition yesterday and brought back with her all sorts of squishies both tiny and small from sites of diffuse venting around the high-temperature hydrothermal vents far below the ship. Being that I am a geophysicist, I don’t fully understand all the biological-type analyses her group is doing with the captured creatures, but word has it that they are studying succession processes (how organisms colonize new sites and how those communities change over time), and infection processes (how young tube worms that start their lives without their required compliment of chemosynthesizing microbes eventually acquire them). Pretty interesting work!

Carl Robinson of the British Antarctic Survey waiting patiently as the code he wrote to control the camera system does what it is supposed to do.

Carl Robinson of the British Antarctic Survey waiting patiently as the code he wrote to control the camera system does what it is supposed to do.

Meanwhile, Carl and I have been making final adjustments to the camera system before its scheduled deployment on Sunday. We are making small tweaks to the code that controls the automatic exposure routine so the video we collect will be suitable for the image analyses we’ll complete after recovery. Although we hope to get good science from the data we collect, this is the maiden voyage for this particular instrument, and our attention is mostly directed at making sure that the apparatus is  properly configured for easy positioning by the sub’s manipulator arms and that we get a few days worth of good video with good light levels. Many more adjustments will probably be required before the system is ready for a long term deployment.

The business end of the seafloor camera system that will make flow rate measurements at a high temperature hydrothermal vent.

The business end of the seafloor camera system that will make flow rate measurements at a high temperature hydrothermal vent.

On yesterday’s dive Monika spent some time scouting around for a good location to place our camera system, but none of the sites she visited will do the trick. This is a bit of a problem for me because I need to know a little about the geometry of the environment around the vent so that I can adjust the tripod accordingly. For this reason my dive has been bumped back one slot and Scott’s dive has been rescheduled for tomorrow. Scott has has agreed to do a little more scouting for me before he gets on with his pressure measurements. Problem solved. Hopefully.

Scott’s work is also pretty cool. This is the second year of his three-year campaign to take pressure readings at

Chief Scientist Scott Nooner talks to other members of the science party about his pressure recording instrument.

Chief Scientist Scott Nooner talks to other members of the science party about his pressure recording instrument.

a set of concrete benchmarks that he placed along the ridge axis and off to one side. The pressure at the bottom of the ocean changes slightly over time because the shape of the seafloor changes as magma moves around below. Scott’s experiment will help us better understand the dynamics of plate tectonics and how new crust is formed at mid-ocean ridges. I’ll try to keep you posted on how this project and all the others go during the cruise.

Gumby Suits

Mountains Under the Sea - Thu, 12/17/2009 - 18:16
Carl Robinson putting the finishing touches on his suit.

Carl Robinson putting the finishing touches on his suit.

The first day of any UNOLS cruise is filled with myriad meetings, briefings, and safety courses. All new crew members and scientists are provided a comprehensive orientation to introduce them to many of the ships operations, safety equipment, and procedures. Among other things, we learn about separating our plastics from the biodegradable trash, what kind of footwear is required outside living quarters and on deck, and how to properly return movies into the collection once we are finished with them.

Nora Nikolov cinches her suit with a smile.

Nora Nikolov cinches her suit with a smile.

We also learn about more serious things, such as where to muster and what to do in case of fire, if someone falls overboard, or in case we need to abandon ship. For all who’ve never done it, this training includes donning an immersion suit, also known as a “gumby suit”. This is usually a pretty fun exercise because the suits are somewhat difficult to put on so, and everyone seems to have their own favorite technique. Once they are on it is hard not to laugh at how silly the outfit looks. All kidding aside though, these suits save lives, and although I hope I never need to use one, it’s good to know there is one onboard for every member of the science party and crew.

Journey to the EPR

Mountains Under the Sea - Thu, 12/17/2009 - 11:45
Atlantis alongside in Manzanillo, Mexico

Atlantis alongside in Manzanillo, Mexico

Yesterday we set sail from Manzanillo, Mexico, bound for a hydrothermal vent system on the East Pacific Rise (EPR) near 10 degrees North.  The EPR is part of the world’s mid-ocean ridge system where new crust is formed as Earth’s plates spread apart. Many of the most exciting Earth processes occur at mid-ocean ridges, including volcanic eruptions, earthquake swarms, deep circulation of ocean water into the crust and the ejection of that water back into the ocean at the site of high-temperature hydrothermal vents. These vent sites are also home to exotic and strange life forms that make their living from chemicals in the warm fluids, and may hold important secrets about how life on this planet originated and evolved, and how life in other parts of the universe might survive. Our mission on this cruise will be to learn more about how these intriguing environments work.

We are headed to the EPR aboard the R/V Atlantis, a 274-foot research vessel and the tender to the human occupied submersible Alvin. This is a large and capable world-traveling vessel that was built specifically for the kind of research that we do. Atlantis has an extensive suite of scientific instrumentation including multibeam sonar systems, winches and cranes for launching buoys and sensor packages, dynamic positioning, and of course Alvin, the deep-diving submersible that will take us to the seafloor to do our research.

There are approximately 20 scientists onboard this cruise, including a few graduate students and a few technicians. We comprise four different teams, each with a primary mission for the cruise. A group led by Dr. Monika Bright will be gathering biological samples for a variety of analyses, a group led by Dr. Spahr Webb will be recovering a set of bottom pressure recorders that have been collecting data on the seafloor for a couple of years. A group led by Chief Scientist Dr. Scott Nooner will be making pressure recordings at a number of benchmarks along and away from the ridge axis to measure how the shape of the seafloor changes over time. And my group (really just me and my engineer) will be deploying a prototype seafloor camera system capable of measuring flow through black smoker hydrothermal vents over long periods of time.

We will be arriving on station early tomorrow morning, and soon thereafter we will launch the sub for the first of about 10 total dives. In this space over the coming two weeks or so, I’ll try to keep a log of some of the interesting things we see and do during this cruise. Please let me know what you think or if you have any questions. I’ll try to answer anything that comes up in the comments. Cheers!

Climategate, global warming, and the tree rings divergence problem - The Christian Science Monitor

TRL Featured News - Mon, 12/14/2009 - 16:19
Much discussion of the Climategate e-mails has centered on tricking tree ring data that may not confirm global warming. Quotes LDEO scientist Roseanne D’Arrigo and discusses her tree ring work in Alaska.
Categories: TRL

Four Times Around the World in 40 Days

Ice Bridge Blog - Tue, 11/24/2009 - 10:01

The Patagonian ice fields seen from 35,000 feet

For the first time in more than 40 days, the nose of the NASA DC-8 is pointing north after taking off from Punta Arenas airport. We have completed our Antarctic survey flights and are heading back home to Palmdale, California. But before we start climbing to cruising altitude we are flying at 300 ft above the Strait of Magellan just outside Punta Arenas to collect atmospheric chemistry data. After two passes over the strait, we head north towards Santiago and enjoy the spectacular view of the Patagonian Ice Fields and the Torres del Paine from 35,000 feet.

Over the past five weeks, the ICE Bridge teams have collected a landmark data set over Antarctica. We had originally planned to fly 17 missions but actually accomplished 21. We have flown more than 155,000 kilometers or almost 100,000 miles. This is almost four times around the world in 40 days. During this time, we collected high precision measurements of the ice surface elevation of many glaciers and ice shelves in Antarctica. We have also mapped the thickness of the glacier ice and snow cover, have measured the freeboards and snow thicknesses of the sea ice in the Weddell and Ross Seas, and have collected gravity measurements that will allow us to estimate the water depth beneath the floating glacier tongues. We have collected an enormous amount of data and are keen to analyze it with our colleagues when we are back in our labs. From the analysis of this data we will gain a much more detailed understanding of how the glaciers, ice sheets, and sea ice respond to changes in the climate system.

A project of this size is only possible with the support of many people. We could not have done this without the help and support of our Chilean friends and colleagues in Punta Arenas and Valdivia, the airport and hotel staff, and the many NASA and university people back home who have worked long hours to make this project happen. We thank NSF for giving us access to their forecasts, and help and assistance from the forecaster at the British Rothera Base (thanks Tony). For planning our flights, we also acknowledge our use of and dependence on the UCAR/NCAR NSF-supported Antarctic Mesoscale Prediction System. We had terrific aircraft crews both in the air and on the ground as well as excellent science teams. We all had a great time in Punta Arenas and are looking forward to come back next year for another ICE Bridge campaign over Antarctica.

Map with flight lines of the Operation ICE Bridge 2009 Antarctic campaign.

Map with flight lines of the Operation ICE Bridge 2009 Antarctic campaign.

A Breathtaking But Fragile Landscape

Ice Bridge Blog - Tue, 11/17/2009 - 15:31

Valley of Ice

The ice in this valley is moving towards the coast

Michael Studinger, Instrument Co-Principal Investigator, Lamont-Doherty Earth Observatory:

PUNTA ARENAS, Chile–The weather forecast for our survey over the Larsen C Ice Shelf looks good. Given the difficult weather over the past couple of days this is a welcome change. After studying satellite images and computer models and talking to the meteorologist at the Punta Arenas airport we decide to fly. We will follow the flow of ice from Antarctica’s interior to the ocean where the ice breaks into icebergs and eventually melts.

The flight will take us through an almost complete tour of the Antarctic cryosphere. Our tour begins over the small ice caps of the Antarctic Peninsula. The snow and ice that forms these ice caps eventually flows downhill through steep valleys, reaching glaciers and ice streams.

Larsen Ice Shelf

Glaciers flowing down steep valleys transport ice from the interior of Antarctica to the Larsen Ice Shelf near the coast

I am seated in the cockpit behind our two pilots to get a better view of the scenery. We are descending into a steep valley filled with ice on its way to the remnants of the Larsen B Ice Shelf that broke apart a few years ago. The ice here forms a huge floating surface that appears endless. Warm seawater lies below the ice; we are here to study how it melts the ice shelf.

The ice flowing into the valleys is pushing the ice shelves away.  Eventually huge ice chunks break off to form icebergs. Our next survey line takes us to the edge of the ice shelf where several gigantic icebergs can be seen floating in the distance, along with pools of open water. After crisscrossing what’s left of Larsen C we head back to the crest of the Antarctic Peninsula and repeat a different survey line. Each time I look out of the window I see a breathtaking but fragile landscape.

Our tour ends at the edge of Larsen C Ice, where sea ice meets open water.

Our tour ends at the edge of Larsen C Ice, where sea ice meets open water.

Heading home.

Heading home.

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