Time series of deployment and recovery. Photo Credit: Ernie Aaron.~Ernie
It takes a team of people to get the OBS in the water and back out again. To illustrate the process of deploying a WHOI or SIO OBS, Gary Linkevich has created a time lapse video. The first part of the video captures two WHOI OBS deployments with Peter, Dave, Dylan, Gary, and Kate. The WHOI OBS are the peanut shaped yellow capsules that appear in the background next to the railing. After the WHOI OBS is in the water, we capture an SIO OBS deployment with Mark, Dylan, Gary and Kate. The SIO OBS are the rectangles with a yellow top and white base. Right after we deploy the SIO OBS, we start putting together a new one for deployment. The assembly process involves an instrument test and then attachment of the metal weight, floatation devices, light, and radio together. The deployment of this SIO OBS happened during the midnight crew shift which includes Ernie, Pamela, Afshin and Jenny. Once they pick her up and put her in, they start the assembly process all over again!
Thanks Gary for putting together this time lapse!
See you Later,
Kate Volk aboard the R/V Endeavor
One of our assistant engineer, Kurt Rethorn, gave us a tour of the engine room. Here's what we learned:
Kurt is an awesome tour guide!
Water quality (Photo credit: Kate Volk)Sea water temperatures in the Gulf Stream are pretty warm (Photo credit: Kate Volk)
Tropical mountain ranges erode quickly, as heavy year-round rains feed raging rivers and trigger huge, fast-moving landslides. Rapid erosion produces rugged terrain, with steep rivers running through deep valleys. However, in a number of tropical mountain ranges, landscapes with deep, steep valleys transition quickly into landscapes with low-sloping streams and gentle slopes at high elevations. This topographic contrast between high and low elevations poses a problem for geologists. Though heavy rains fall throughout the mountain range, erosion seems to sculpt parts of the mountain differently from others.
Mount Chirripó, Costa Rica’s highest peak, bears exactly this type of terrain, with flat valleys at high elevation capping rugged valleys below. The beveled summit of Mount Chirripó bears striking resemblance to summits as far away as Taiwan, Papua New Guinea and Uganda. Some geologists think that tectonic forces deep below earth’s surface pushed Chirripó into its flat-topped form about 2.5 million years ago. Others think glaciers did the work, sculpting the peak in over hundreds of thousands of years.
Max Cunningham, a graduate student at Columbia University’s Lamont-Doherty Earth Observatory, traveled to Chirripó this past summer to test the idea that mountain glaciers carved the summit we see today. Working with his adviser Colin Stark, a geomorphologist, and Michael Kaplan, a geochemist, both at Lamont-Doherty, Cunningham chiseled away samples of glacial debris to take home for analysis. The researchers hope to eventually pin down when the high-elevation valleys capping Mount Chirripó’s summit eroded into their current form. Read more about their work in the above slideshow.
Photos by Max Cunningham unless otherwise credited.
It was nearing time to launch the next expendable bathythermograph probe, or XBT. The software was readied and two scientists headed out of the lab, radio in hand. They donned lifejackets that had once been bright orange but were now closer to a dull rust color from long and dirty use on the deck and selected a T-5 probe from the box.
Out on the deck they were alone, perched partway up the stack of levels in the stern of the ship, the gun deck below them and the paravane deck above. It seemed that the others working the graveyard shift were all inside, perhaps wrestling with some mechanical puzzle or else simply keeping watch to make sure all was well, sipping strong coffee, playing cards to pass the time. The scientists snapped the probe into the gun-shaped launcher. They removed the plastic end cap from the black cylinder that housed the probe and its spool of fine copper wire.
“We’re in position.”
There was a pause, then the radio crackled back, “Launch probe.”
In a moment the probe was sliding down the long tube that extended out and downward from the starboard side. With a small splash it plunged from the end of the tube into the inky deep. Now to wait while it made its journey towards the bottom, more than 4000 meters below. Despite the very late (or very early, depending on your point of view) hour, it was warm. The air was muggy – not exactly a welcome change from the air-conditioned lab, although the tinge of diesel fumes was less out here in the relative open. There was little wind and the seas were calm. Standing on the moving island of light that was the ship the sea quickly disappeared into the surrounding void. What surface that could be seen appeared to rise disturbingly close up alongside them, like a churning wall of water. It was only visible at all by the few swirls of foam formed by the ship’s passage and a reflection here and there off the constantly moving face of the black oily-looking water. They waited for the go ahead to terminate the probe.
Down in the lab, there was a strange blip on the screen showing the multibeam bathymetry data, but no one noticed as they were too busy entering in location data for the XBT or scrutinizing the movement of the streamer birds that regulated the depth of the hydrophone streamer. There were, after all, 36 other monitor screens to watch.
Outside there was a louder than usual splash. The two scientists peered into the gloom.
“Dolphin?” one wondered out loud.
“While we’re shooting? I hope not,” the other replied, “We’ll end up having to interrupt the line.”
Was there something just under the water surface? A pale sinuous shape at the very edge of the ship’s halo of light? No, it must be a trick of the light and the weird perspective engendered by the lack of any sense of distance. Perhaps more coffee was in order when they got back inside.
The radio crackled again, “Terminate probe.”
The scientists broke the wire that was still spooling out to the probe that was now falling behind them. “Probe terminated,” they reported. They were just turning to leave when it emerged.
At first it looked like a whale back, though pale milky green in color rather than the expected grey. As it lifted free from the surface it became clear that it was much longer than an orca or even a grey whale, more like an ancient marble column turned soft and rubbery. It tapered as more of its length was exposed until the tip broke free of the clinging water. One side of the enormous snake-like shape was covered with round suckers the size of dinner plates in a poisonous green color. The cyclopean tentacle towered out of the water, waving gently with a sickening sort of grace ten meters or more above the uppermost deck. Here and there along its length were clots of a coppery tangled substance, almost like seaweed wrapped around it. “The XBT wire,” one of the scientists realized from the midst of her fascinated horror.
The tentacle hovered for another movement before swooping down with surprising swiftness. The two scientists were neatly plucked from the ship in the blink of an eye. With a clatter, the radio fell to the deck. They were held above the water for a long moment, crushed together so tightly they couldn’t speak and could barely draw breath. Then, slowly, the tentacle disappeared beneath the smoothly rolling waves.
Two hundred and sixty-seven shots until the next XBT.
-by Tanya Blacic aboard the R/V Langseth (with a wink to H. P. Lovecraft)
Our small ship is in a state of endless motion with pitch, roll, yaw, and heave. We continuously experience a feeling of fluctuating gravity at sea, as one minute we are several pounds heavier and the next we are several pounds less. We’re tossed about endlessly like riders at the fair. It’s a feeling that can turn the stomach of the saltiest of sailors, but more often disturbs the newbies the most. At sea there is also no such thing as silence. Out here the engines are always running, hydraulic pumps are always droning, and ships operations occur around the clock. From my bunk I can feel us lurch forward and lean into a turn to starboard, or port, and then they reverse the pitch of the propeller as if applying an emergency brake to slow the ships forward motion. This reverse pitch causes a shudder in the hull that shakes us like a cheap hotel vibrating bed and it chatters every moveable thing. From my bunk I can also hear the acoustic pings emanating from the hull-mounted transducers. Speaking to me in code, they tell me if OBS operations are going well. Based on the ping styles I can also discern the acoustic techniques used by WHOI and Scripps, so that I know which instrument type is being talked to. All of this information creates a movie in my mind that plays out until I fall asleep. Life on a ship is a constant immersion in all that is going on and for 30-days there will be no escape.
Kara and Matt are entranced by velocity analysis
Perspective view of seafloor depth from MGDS across the continental slope overlain by a higher resolution swath of bathymetric data that we acquired along our transect, which is also shown projected onto the seafloor.
Preliminary image of a salt diapir in seismic reflection data near the base of the continental slope. The y-axis shows the time it takes for a sound wave to travel down in the earth and back again. This images shows about ~5 km down into the earth below the seafloor. Donna Shillington aboard the R/V Langseth
Today was the first day of the onshore deployment of the RT130s through southern Virginia and North Carolina. My partner, Yanjun Hao, and I, were just one of five teams working to deploy instruments along the two survey lines. We deployed the first two instruments at West Harnett Middle School and South Hartnett Elementary School, both outside of Lillington, NC. In both case, the fifth and sixth graders were very interested in learning about what we were doing and eager to participate. I explained to them the basic concept of P and S-waves and then asked the children to jump so that we could test that each of the channels on the sensors was working correctly. They very much enjoyed getting to see on the clié exactly what the signal they generated looked like. At both schools, I was surprised how much the children, and the teachers, knew about earthquake seismology and the intelligent questions they asked. A teacher asked whether they would detect the explosives detonated at nearby Fort Bragg, and a sixth grader named Gauge blew me away when he asked if the sensors would be able to record the sound waves generated by the planes or nearby explosions! In total, we probably spoke to 100 kids about the project today. It was a very encouraging to see how excited and interested they all were in the science. When we first arrived and explained that we would be installing a seismometer, a 5th grade teacher looked at us with wide eyed and asked "Are you seismologists?!" I nodded yes and she was so excited she started jumping up and down. Despite some rain and GPS trouble later in the day, the excitement that the elementary and middle schoolers showed about seismology was enough to make it a great start to the deployment.
Posted by Christopher Novitsky
Posted by Beatrice Magnani
See ya'll later,
For those of you following at home, it might be a bit confusing on which ship is doing what and where. I've made a little cartoon timeline that will hopefully illuminate our progress so far.
There are two ships currently in the Atlantic: the OBS deploying R/V Endeavor and the seismic shooting R/V Langseth. The R/V Endeavor has been putting OBS down and picking them back up again on lines 2, 3, and 4 while the R/V Langseth has shot seismic along line 2 and 3, and is going to head over to shoot on line 4 soon.
See you later,
Kate Volk aboard the R/V Endeavor
Well we have finished deploying OBS on line four and are now transiting back to the beginning of line 3 to start picking OBS back up again. At this point, we've all fallen into our jobs and are working like a well oiled machine. Each shift was able to deploy around 9 or 10 OBS in 12 hours time, moving smoothly from one site to the next. To celebrate our progress so far, I've got some group photos to share.
The science party from left to right: Gary, Dylan, Afshin, Harm, Brandon, Pamela, Jenny, and Kate (Photo credit: Dave DuBois, edited by Gary Linkevich)
The WHOI and SIO OBS technicians from left to right: Ernie, Peter, Mark, and Dave (Photo credit: Gary Linkevich)
The whole science group (Photo credit: Ethan, edited by Gary Linkevich)
The science group in the WHOI van with the WHOI OBS (photo credit: Dave DuBois)See you later,
Kate Volk aboard the R/V Endeavor
Leveraging Local Knowledge to Measure Greenland Fjords: Understanding the Community
Project Background: Changing conditions in Greenland’s northwest glaciers over the last decade have led to a range of questions about water temperature and circulation patterns in the fjords where ocean water meets the glacial fronts. We can use satellites to measure the loss of elevation, the acceleration of ice flow, or the retreat of ice from a glacier, but we can’t use satellite measurements to collect water column temperature profiles. Water column profiles would allow us to better determine how much melt is possible at the glacier connection to the ocean, and help us pinpoint why neighboring glaciers are behaving differently.
The Leveraging Local Knowledge project will work with members of local Greenlandic communities to collect water measurements in the fjords. This will assist in determining if warming Atlantic Ocean water is circulating up through Baffin Bay where it enters the fjords to lap against the frozen glacier footholds, causing them to loosen their hold on the rock below. Alison Glacier (74.37N and 56.08W) is selected as the project focus. Emptying into Melville Bay to the east of Kullorsuaq Island and has been undergoing dramatic change over the last decade.
Our Journey: Our research trip to the small village of Kullorsuaq is a journey that will start 200 kms to the south in the community of Upernavik, located 800 kms north of the Arctic Circle. Flying in on a small 37 seat Dash 7 airplane we overlook a coastline that is lined with glaciers flowing into a bay that is dotted with islands. Most are uninhabited, but Upernavik is home to a population of 1500 permanent residents. An island community, the main employment is fishing with the waterfront sporting a range of both commercial and smaller independent fishing boats.
Upernavik town was established by the Danes in the late 1700s but trade and a religious mission in the early 1800s cemented it as a permanent settlement. The southern end of the island is dotted with a cross covered graveyard representing the religion the Danish settlers brought and the practice of the current community. Christmas, Three Kings Day and other religious holidays are all causes for the community to celebrate. This week the priest will visit Upernavik to celebrate three weddings (Friday and Saturday) and the Confirmation (Sunday). With all such events scheduled for when the priest can preside the parties and celebrations will involve the whole community for days. Celebration and gatherings are a large part of this community’s practice.
The Setting: The icebergs being sloughed from the neighboring glaciers dominate the horizon, littering the waterfront with ice ranging from house-sized blocks to looming masses that appear as large as the neighboring islands. Looking around at the open water it is hard to imagine the origin of these large masses of ice. The closest blocks of ice move during the course of the day, shifting back and forth from north to south and back again. With the shifting and changing of the icebergs the sound of the settling and collapsing of ice is drilled into our consciousness – the sharp crack of the ice as if fractures and the larger canon-like rumble as sections break and fall into the water.
Our local host, a Dane who has lived in Upernavik for 40 years, has fully blended himself into the community where he and his family are well known and liked by both the Inuit and the Danish population. When he learns of our project he observes that in his time here ice cover has significantly changed. He recalls his early years here when the ice in May was so solid in the bay that visiting boats had to drop dynamite on the ice to open a pathway. He points to the open water and the line of haze that hangs on the horizon offering a cause, ‘global heating’.
Other changes have hit Upernavik. We meet a Danish couple who had spent 4 years living in the community, now returning after 30 years to ‘close out their memories’. They spoke with fondness of this lost time when they raised their small children as they worked as a teacher and a nurse. With a team of 10 dogs ‘Lars’ had hunted Greenlandic seal and still had a sharp eye picking a bobbing seal head out on the horizon. They spoke of the people numbering 900 while the Greenlandic dogs had numbered 3000, many times more than the dogs are now. Dogsleds were an important part of that older Upernavik when individual hunting and fishing were the mainstay of the community. While hunting and fishing are still important today Lars notes that things have changed becoming less rugged for an individual. Whether the changes in ice cover have played a part in this is hard to determine.
In our few days here in Upernavik we learn that residents are happy to help, they have networks that reach from one island community to another. Names and contacts are offered freely – “try this person for a place to stay”, “this teacher may be interested in helping you”. It is this networking of local people that we will rely on for the project. Their overall interest in what is happening to their community will be an important part of its long term success.
Leveraging Local Knowledge to Measure Greenland Fjords:
Dave Porter and Margie Turrin are in northwest Greenland working with local community members to collect water column temperature profiles. The project is funded by a Lamont Climate Center grant with support from the NASA Interdisciplinary Program and logistical support from NSF.
By Max Cunningham
June 12, 2014
We continued to sample boulders in Valle de Las Morrenas, Valle Talari, where the hostel sits, and several places along Mount Chirripó’s ridgeline.
The view from the top of Mount Chirripó is spectacular. Looking out along the ridge I could see huge boulders of granodiorite produced by exfoliation, or the response of rock at the surface to the removal of ice.
The actual summit of Chirripó, however, is a very different kind of rock. I believe the peak is composed of a sedimentary rock that was melted and then fused back together as the magma that formed the granodiorite rocks moved toward the surface. This metamorphosed sandstone (meta-sandstone) is extremely hard, and resistant to weathering processes.
In the meta-sandstone near the summit of Mount Chirripó, I discovered glacial striations. These striations occur at 12,513 feet (the summit is 12,529 feet), which is a good 1,000 feet above the moraines in the upper portion of Valle de Las Morrenas.
By Max Cunningham
June 11, 2014
Mike and I hiked down 7,000 feet from Mount Chirripó to the Cloudbridge
Reserve early on the morning of June 10th to refuel and replenish supplies.
At this point, the Cloudbridge Reserve deserves a special mention. Tucked away in the forest above San Gerardo de Rivas, volunteers at the Cloudbridge Reserve work to transform old farmland into natural forest. After the cold ruggedness of the Mount Chirripó summit, the volunteers at Cloudbridge provided an exceptionally welcoming and engaging environment. Mike and I were extremely lucky to have such a supportive base camp.
I kept an eye out for interesting geomorphology as I walked along the trails of the Cloudbridge Reserve. The rivers here are particularly beautiful. The water is clear and blue, and channel beds are floored by bedrock and boulders (all granodioritic in composition, like many of the rocks atop Mount Chirripó). I was struck by the power of the local rivers; the erosional features carved into this hard, granodioritic rock were impressive.
After two days of rest and catching up on all we’d missed while isolated on Costa Rica’s highest peak, Mike and I headed back up to Mount Chirripó to continue sampling and to learn more about the processes shaping this landscape.
During our second journey, we hoped to extend our sampling range by venturing farther into glacial valleys and higher onto peaks. We targeted Valle de Las Morrenas, a valley that we knew well from our first sampling trip and that other researchers had discussed extensively.
Earlier, we sampled boulders from moraines adjacent to large lakes. This time, we targeted a steep drop-off (what we called a “lip) that occurs in the valley directly below the lakes. Looking at maps and satellite images, it appeared that the lower valley was actually a remnant cirque:
Our discovery of a large lateral moraine in the lower valley corroborated our hypothesis that a glacier produced the pronounced lip in Valle de Las Morrenas. The vegetative cover increased substantially as we moved lower in the valley, which made accessing the moraine a real challenge. After pushing through thick, woody bushes, we finally found ourselves on the crest of the moraine.
From the image it’s hard to tell, but this is actually a pretty big moraine, about 50-60 feet in height. Meandering rivers cut through cobbles along the moraine’s edge, analogous to what we saw in Sabana de los Leones, only here with water raging through the channel.
We quickly came to realize that the boulder selection on the crest of this lower moraine was a far cry from the beautiful, large, flat boulders we saw along moraines in the upper valley. Here, boulders seemed to be more deeply weathered, and more sparsely scattered.
While the lack of good boulders for sampling induced a bit of hand wringing (made worse by storm clouds quickly moving up the valley), the effectiveness of weathering on these boulders may add to the story of glaciation at Mount Chirripó. Deep weathering of boulders suggests that they have been sitting around, exposed to the atmosphere, for a long time. How long? Glaciologists have employed relative weathering techniques for centuries to estimate exposure age, but 10-Be dating will tell us for sure.
Kristen de Graauw and Cari Leland
Cari and Kristen here, checking in from Mongolia. This year we were invited to be instructors for the Third National Dendroecological Fieldweek, May 23-29 in Udleg, Mongolia. We arrived to Ulaanbaatar on May 20th so we were fortunate enough to have a few days to recover from some pretty terrible jetlag before beginning the fieldweek marathon. Anyone who has ever attended a fieldweek anywhere in the world knows how challenging (and rewarding!) these events can be. Our first few days of the fieldweek were spent at the NUM (National University of Mongolia) research station near Udleg, a few hours north of UB. We were so happy to see the beautiful countryside for a few days. We got to ride there in this awesome Russian vehicle, which Cari nicknamed Herbie.
The research station was a complex of buildings for housing, a kitchen, and lecture rooms. We shared a cozy room for two and enjoyed beautiful views of the valley and mountains surrounding us.
After everyone settled in, we met for the opening ceremony. Baatar gave a nice introduction of the project and the history of the CEME collaboration. There were 8 students in total, and 7 of them were female (girl power!). There was a good mix of participants; from first year undergraduates to PhD students.
After the opening ceremony we went out to the field. Baatar gave us a guided tour of all the current research projects at the station (there were many!) and the potential sites for the fieldweek. Then we gave a quick lecture on the basics of dendrochronology and headed back towards the research station to discuss potential fieldweek projects.
Day 2 at the research station was field sampling day. Unfortunately we woke up to a cold and rainy day but that didn’t stop our groups from heading out into the forest. After a long discussion we decided Cari would teach the Climate group and Kristen would teach the Ecology group. Cari’s group headed up the mountain in search of old larch and pine trees to core while Kristen’s group went to a portion of the forest that had been logged. The goal for the climate group was to find moisture-stressed trees and look at the relationship between tree rings and climate. The ecology group’s goal was to determine logging dates and the effects on surviving trees.
After one of the coldest and rainiest field days we’ve ever experienced we headed back to the field station to thaw and dry ourselves and the cores.
While we waited for the cores to dry, the students practiced skeleton plotting.
The next day we mounted the cores with glue and taught the students how to sand. They quickly learned that a well sanded core took time, patience, and persistence. At the end of the day we headed back to UB to begin laboratory methods.
Back at the university we had to hit the ground running with lab methods. The students skeleton plotted the samples from the research station one day, learned how to do the list method and measure the next day, and finally on the last day they learned how to run COFECHA and read the output files. It was challenging but everyone worked their hardest. The final day was very busy. The students were working on their presentations until the very last minute. The groups did an outstanding job presenting their projects, which made us feel so grateful for being able to teach such a bright and dedicated group of students. During the closing ceremony Baatar gave us both a really nice Mongolian tree and shrub guide book and then presented each student with a certificate of achievement. The students then gave us the most thoughtful gifts of Mongolian art and script.