News aggregator

Preparations for the storm

Mapping the Galicia Rift off Spain - Mon, 06/17/2013 - 01:08
As a follow up to Donna's post, we are making individual preparations, which include taking the motion sickness medicine of choice or default depending on where you come from.
Spanish, English, and American motion sickness remedies.
 We are also securing (tying down) our stuff and preparing our beds, which includes a new to us method coined "tacoing." To "taco" a bed means to use whatever you can find e.g. dirty clothes, luggage, random foam (Luke found some foam in the bird lab) in order to form a taco shape between your mattress and the wall. This way the roll has less of an affect on you as you try to get some sleep.. At least that's the theory.
My laptop's ready!
Brian in a reasonably "taco'd" bed... And Luke's version.

Will update from the other side of the storm.

James Gibson

Storm a Comin'

Mapping the Galicia Rift off Spain - Sun, 06/16/2013 - 21:06
For the last week, we have been enjoying relatively calm seas.  Swells rolled in from distant storms, but the local weather was quite enjoyable. Now the storm that pummeled the east coast of the US last week is headed our way. This storm is expected to give us winds up to ~36 knots and ~7-8 m (~21-24 ft) waves!  This is too rough for the more vulnerable components of our gear such as the airguns, which are dangling beneath floats behind the ship.  Additionally, our data quality suffers when the weather worsens. When the winds pick up to ~25 knots, we’ll pull in some of our gear, and then turn around to face the storm and ride it out.  In the meantime, we are preparing by strapping things down in the main lab and stowing loose items that might roll around and fall over once the ship really starts to roll.
Wish us luck!
Donna Shillington
17th June
Map of forecast wave heights posted in the main lab. The big bulls-eye is right over our field area...

Hello, sunshine

Mapping the Galicia Rift off Spain - Thu, 06/13/2013 - 04:31

We have been at sea for nearly two weeks, and during this time we have seen many things… the hints of exciting geologic structures under the seafloor in our data, waves, whales, gear going off the stern. But we have seen very little of the sun, until today.  Most days have been overcast and grey. Now that all the equipment is deployed, there is nothing requiring us to be outside except for the occasional XBT launch, so it’s easy for a day or two to go by without going outside at all. It is even possible to be totally unaware of the weather for long stretches of time since the main lab, where we spend most of our time, is windowless and below the water line. Instead of windows, we have monitors showing what is happening out on various decks from a series of cameras around the ship.  Today they showed bright sunshine reflecting off the water behind the ship.  After spending a few minutes out in the sun on the deck, my unaccustomed eyes are still seeing spots…. Back to the lab!
Bern and James are on watch, so they can only watch the sun on TV from the lab.
 Donna Shillington
13th June

Miracle workers of the Langseth overcome the curse of the Costa da Morte

Mapping the Galicia Rift off Spain - Mon, 06/10/2013 - 14:28
After days of uneventful and productive data acquisition, a pall fell over the R/V Langseth. Early Sunday morning, one of the streamers began to report communication errors and soon failed to communicate at all.  A series of tests over the ensuing hours revealed that the problem was not on the ship but in the equipment out in the water.  Recovering and repairing seismic gear is not a quick task. To access this streamer, we had to undo many of the steps required to put it out to begin with: recover the port paravane, shift Streamer 3 starboard and out of the way, and then reel in part of Streamer 4. After hours of troubleshooting, the technical staff of the Langseth brought Streamer 4 back to life.  All of the equipment on the Langseth is… not new, and this certainly applies to the seismic streamers. The technical staff on the ship are pros at keeping this equipment alive (and many cases bringing it back from the dead). Twelve hours after the problems with Streamer 4 began, it was back in the water, and we were ready to start collecting data again. 
But no sooner had one problem been solved, another appeared. This time the trouble arose from the failure of a piece of equipment on the ship that is at the heart of our acquisition system – the real time navigation unit (or RTNU, for those in the know). This component gathers satellite and other navigational information from the seismic equipment and delivers it to the navigation software on the ship so that we can determine the positions of all of our equipment in the water, and where and when we need to be shooting.  Once again, the dedicated technical staff of the Langseth came to the rescue.  Painstaking checking and double-checking of each component in the RTNU began last night and continued into the early hours of the morning. In the wee hours, it’s easy to get a little superstitious.  Did all these problems arise because Tim Reston and I each accidentally drew in lines on our chart indicating that we’d completed lines in our 3D box before we actually had? Or was it the curse of Costa da Morte (Coast of Death)? This part of the Galician coast is known for its shipwrecks and nicknamed accordingly. Of course, the real culprit was the non-newness of the gear in question. Once again, the Langseth’s miracle workers saved the day by assembling the working parts of various old RTNU’s into one working unit.  Thanks to their efforts, we are up and running again….

RTNU carnage on a table in the main lab.
Donna Shillington
10th June

Poseidon Visits (and Seismic Oceanography)

Mapping the Galicia Rift off Spain - Mon, 06/10/2013 - 13:41
One of the secondary activities on the cruise has been the deployment of XBTs off the stern. XBTs are a standard oceanographic tool designed to measure the variation of water temperature with depth, providing information on mixing processes within the water column. As temperature is one of two primary controls on velocity of sound in water (the other being salinity), it is also of interest in the processing of our bathymetric data.

Poseidon's Zodiak on the way over to exchange supplies.
A few years ago, it was realised that seismic provides a method of directly observing the mixing processes, as the different water layers have sufficiently different seismic velocity and salinity for reflections to be generated at their boundaries: we have already seen reflections in the water column of our data, probably from boundaries between North Atlantic water and warmer, more saline Mediterranean water. However there have been relatively few studies of these processes using traditional oceanographic and seismic techniques, a deficiency being rectified by the deployment of XBTs at regular intervals during our cruise.

A successful exchange on medium-high seas!!
In addition to deploying ocean bottom seismometers to record our seismic shots, the German research vessel F.S. Poseidon has been carrying out oceanographic measurements, mainly using CTD casts (conductivity-temperature-depth), which provide more information than XBTs. As a result they had several XBTs left over. These they transferred to us this morning: Poseidon came within about 1 km of the Langseth and sent the XBTs over in a small boat. A real bumpy ride!

Goodbye, until we meet in Vigo!Tim Reston
University of Birmingham

Poseidon: OBS deployment update

Mapping the Galicia Rift off Spain - Sat, 06/08/2013 - 08:13
On 5th of June, Poseidon deployed her last three OBH instruments. The crew then spent the next two days doing CTD ("conductivity, temperature, depth") measurements of the water column. They typically recovered good measurements of conductivity and temperature for depths down to 1000 m. These measurements can be used to monitor mixing of different water bodies (such as warmer Mediterranean waters with the cold Atlantic) and to calculate variations in velocity within the water column to compare with seismic reflections we observe within the water column. Rough seas for the last 1.5 days have made the CTD measurements challenging.

Today the Poseidon is recovering eight OBH to download the data they recorded and redeploy them elsewhere within the 3-D box. It will be exciting to see the first OBH data! We won't see the rest of the data until the remaining OBS and OBH are recovered in August and September.

Despite being in the same area, here on the Langseth the science party hasn't seen the Poseidon since our first day passing them on the way out to sea from Vigo. However, this may be because we are all busy below deck in the main lab (with no windows) processing data!

Marianne Karplus
8th June

Underway and beginning to collect data

Mapping the Galicia Rift off Spain - Sat, 06/08/2013 - 00:43
For the last couple of days, we have been slowly (very slowly) steaming along at 4 knots (~4.6 miles an hour) towing all of the gear behind the ship and collecting seismic data. A lot of data! Each of the four seismic streamers behind the ship records returning sounds waves on 468 channels. Every time one of our air gun arrays fires, we collect 60 Mb of data.  Repeat that every 16 seconds for a few days, and it adds up.  Even though we have only been at it for a few days, we have already generated 405 Gb of raw seismic data, and that does not include all of the other types of marine geophysical data that we collect (bathymetry, magnetics, etc). Nonetheless, there are many reminders that we still have a long ways to go.  For example, a large map on a table in the main lab shows all 56 profiles that we plan to acquire during this cruise in our target area for 3D imaging (black horizontal lines in the image below). As we complete them, we draw a green line along the profile on the map. Four down, fifty-two to go! 

Donna Shillington
8th June

Map in the main lab showing planned profiles. The ones we've already completed are in green
*Follow our progress on the "Survey Area" page as we update the sail lines every ~4 days.

The Source

Mapping the Galicia Rift off Spain - Thu, 06/06/2013 - 07:07
Our fourth (and final) gun array was deployed last night!! This means that all of the hard work that the crew has performed (with our help, of course) will begin to pay off as the data streams in while we traverse east along the western most extension.

Marine reflection seismology involves actively generating soundwaves (rather than waiting for earthquakes as in many other types of seismology). The ideal seismic source is as close to a “spike” as possible. Sound waves from the source travel into the Earth, where they reflect off sedimentary layers as well as hard-rock surfaces. The returning reflections are recorded by over a thousand hydrophones (underwater microphones that gauge pressure changes created by the reflected seismic waves) in the streamers that we have been deploying for the last four days.

The source consists of a series of air guns of varying sizes, which are hung at a depth of 9m (~30 feet) below large inflatable tubes. The tubes are 60m (~200 feet) long and each has 9 active air guns (10 with one to spare). In our case there are two sets of air guns being towed 150m (~500 feet) behind the ship, that alternately fire. To create a strong source that is as spike-like as possible, the guns are carefully arranged and fire almost simultaneously. The air is released from the chamber of the air gun, creating a 3300 cubic inch bubble pulse, which collapses to create the sound waves.
Orientation of the streamer and gun arrays being towed by R/V Langseth.
The red circles indicate the location of the gun arrays.
We are making sound in the ocean, where many mammals use sound to communicate and hunt for food. In order to ensure we are operating responsibly and minimizing our impact on mammals, we have five Protected Species Observers (PSO’s) onboard who both watch and listen for (from the observation deck in Donna’s previous post) any marine mammal that comes close to the ship. If any are spotted or heard within a specified radius around the ship, we power down the guns until they leave the area.

James Gibson

Langseth: The paravanes are out!

Mapping the Galicia Rift off Spain - Tue, 06/04/2013 - 00:24
Most of the science team came out on deck this afternoon to watch the starboard-side paravane deployed in relatively calm waters under partly cloudy skies. The technical and engineering crew proceeded slowly and carefully through the deployment procedure, and after about a couple of hours the paravane and attached streamer were over 300 m off the starboard side of the Langseth.

The second paravane went in the water at 22:00 this evening, and streamer 2 is currently being uncoiled into the water behind the ship. Despite a few delays, we are making good progress!

Marianne Karplus
4th June

email outage

IT Announcements - Tue, 01/29/2013 - 09:40

 Email for most users was down earlier this morning, January 29.   Service was restored around 9:30 AM..  We are

investigating the cause.

LDEO email back up

IT Announcements - Mon, 12/17/2012 - 10:05

email outage

IT Announcements - Sun, 12/16/2012 - 08:22

Currently email service is down for most users due to multiple hardware failures.  We are working on the problem.  There is no estimate as to when we will be back up.

mail service outage

IT Announcements - Sun, 12/16/2012 - 03:38

 Mail service for many users is down due to mutiple hardware failures.  We are working on the problem.

LDEO email/web outage

IT Announcements - Wed, 11/07/2012 - 15:06

Problems with myUNI, password tools

IT Announcements - Thu, 04/26/2012 - 13:59

Columbia University IT group is investigating intermittent problems with the myUNI services for password changes and resets.  Some users are experiencing long wait times and a <

read more

Network Maintenance Successful

IT Announcements - Thu, 02/23/2012 - 20:31

CUIT successfully updated network maintenance in Lamont-Doherty on Thursday, February 23rd, from 5:00 PM to 6:00 PM, as previously scheduled/announced. During this network configuration change

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Internet's Primary Link Maintenance

IT Announcements - Wed, 02/22/2012 - 10:09

CUIT Network Operations will be performing maintenance on Lamont's primary link to the downtown Columbia campus (our link to the internet) 5-6 PM this Thursday, February 23.

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LDEO mail outage

IT Announcements - Sun, 02/19/2012 - 04:53

 Most outgoing mail was turned off from Sunday, ~12:30 AM until ~3:31 AM because a compromised account was being used to send spam.

Celebrating the end of the Antarctic field season

Using Rocks to Decode Antarctic Climate - Thu, 02/17/2011 - 22:18

We decide today is the last day for our camp, and we pack up and drive back to our base camp, the Central Transantarctic Mountain camp (CTAM). A sadness in a way, because it was our cozy home for a week. We ate, slept, and joked around here night after night. Also, we realize that packing up camp represents the end of the field season, except for one more day. For the last day of work we will fly by helicopter to the Achernar area from the CTAM camp.

Moraines at the Lewis Ice Tongue, the location of the last rock surface sampled during the field season

The last day at Mount Achernar. We use the helicopter to go near the southernmost part of the area, near the Lewis ice tongue, which comes off the East Antarctic ice sheet. After a long day, we collect our last samples, and wait for the helo to pick us up – the end of the field work for this season. We realize we had a very successful field season. Not one day of work was lost at either Mt Howe or Mt Achernar (a very rare experience for Antarctica). We think about how we accomplished our goals in terms of getting to both remote sites and collecting samples.

Spontaneous dance performance celebrating the end of the highly sucessful field season

Back at CTAM camp, we scramble to get all our stuff packed up ready to be shipped back to McMurdo. They are closing the CTAM camp for scientific work in a week because they need to take everything down by the middle of February. The middle of February represents the end of the field work for everyone in Antarctica. It starts to get too cold, and the sun starts setting in some areas farther north. People start to go home then and McMurdo gets ready for the winter.

The 'Antarctica's Secrets' team (Mike Roberts, Mike Kaplan, Nicole Bader, Kathy Licht, Tim Flood) getting ready to fly back to McMurdo station

We all fly back to McMurdo. A bed and running toilets (!) for the first time since we left for our camping trips. Also, the dorms have dark curtains that go over the windows. So, darkness, a bed, and a toilet – who would have known life can get so good!

Mike Kaplan (Lamont)

The Twin Otter, ready to fly the team back to McMurdo

Glacial deposits: A clue to reconstructing the history of the Antarctic ice sheet

Using Rocks to Decode Antarctic Climate - Thu, 02/10/2011 - 11:44

We set out on the snowmobiles with all the sleds to Mount Achernar with all our stuff. After about three hours we reach the site (crossing the flagged crevasse zone with no problem). We are joined by a fifth team member, Tim Flood, a Professor at St. Norbert College in Wisconsin. Tim has expertise in petrology or rock composition. So, we will have one additional person for the Achernar part of the trip.

Kathy Licht, Tim Flood and Nicole Bader exploring glacial deposits near Mt Achernar

At first we only find ‘blue ice’ to set up camp. Blue ice gets its name mainly because – in contrast to the typical situation of having a layer of snow on top of the ice sheet – there is only ice. The snow layer that normally covers the top of the ice sheet is blown away where the winds blow pretty fast and consistently. This means there is no good place for camp right in the Achernar area because all the blue ice is a sign of strong winds. We decide to back up a few miles to where the snow starts again and camp a little but away from Mount Achernar. This means we will have a ‘daily commute’ to get to where we want to work, but at least we have a nice place to live for the week. It is less windy where we decide to set up camp and a nice layer of snow in which to pitch the tents and walk around. Blue ice is very difficult to walk on – it is just what it sounds like – walking on ice!

Setting up just another field camp at Mt Achernar

We set up camp. Unlike at Mount Howe, here each person will have their own tent. In addition, we set up the bathroom tent and a huge kitchen tent, named the ‘Arctic oven.’ The arctic oven will act as a kitchen and dining area. It is about 25 feet long, enough to be comfortable. And, when we have two stoves going inside, the temperature gets up to a comfortable 60 degrees or even higher (hence, its name); comfortable enough to start peeling off all our jackets while eating. Two little speakers that Tim picked up in an airport, attached to ipods, means we even have a stereo system in the arctic oven cook tent.

The first day we drive out to where we want to work. It takes about an hour and a half each way by snowmobile. This is quite a bit of time. In addition, the glacier deposits we want to study are much larger in area compared to at our first site at Mount Howe. It is not practical for us to drive everywhere and get to all the places by walking. We realize we will need to utilize the helicopter from nearby CTAM. So, the next week or so we alternate: a “snowmobile day” when we commute by snowmobile from camp to the field site and “helo days”. On the helo days, the helicopter flies out to our camp (a short flight by helicopter from the CTAM camp) picks us up, takes us exactly where we want to go around Mount Achernar, and then at the end of the day, comes back out to bring us back to our camp. All these trips only take the helicopter folks about 75 minutes in total each day, given how fast they go.

Collecting samples from the top of boulders that got left back by the retreating glaciers. At home in the lab at Lamont, we will use a method called 'Surface Exposure Dating' to figure out when the ice sheet left these boulders behind when it retreated.

We spend the next 8 days or so doing the same sort of work as at our first site Mount Howe. We map the glacier deposits (how red or oxidized are they – how do their elevations changes? How do the deposits themselves change in terms of shape and composition and other characteristics?). Mike K and Mike R (with occasional assistance from others) collect samples for the surface exposure dating, so they can eventually figure out how old all the deposits are. Kathy, Nicole and Tim study the composition and types of glacier rocks and sediments left behind.

Similar to our finding at Mt Howe, we find pronounced changes in the glacier moraine deposits around Mt Achernar. This indicates there are likely deposits of different ages, left behind at different times by the ice sheet when it was bigger. All the team members continue to collect samples that will be analyzed later in the lab.

Running water in Antarctica at Mt Achernar

Mike K, Kathy, Mike R, Nicole and Tim



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