HEALY 1202 Research Cruise

Our team of scientists from the University of New Hampshire and NOAA, along with colleagues from the Navy, USGS, and other organizations, are underway in the Arctic Ocean aboard the U.S. Coast Guard icebreaker HEALY for a seafloor mapping expedition to help the United States define the limits of its continental shelf beyond 200 nautical miles.

  • Read the USGS Ocean Acidification Research Team's Cruise Journal here>>

  • Follow HEALY's Track Map here>>

  • View hourly images from HEALY's Aloftcon here>>

  • See HEALY's position and weather here>>


Capt. Andy Armstrong of the NOAA/UNH Joint Hydrographic Center is one of the chief scientists aboard the Healy. He is sending these notes from the top of the world.


September 27, 2012

Final entry for the project.

We arrived in Dutch Harbor on Unalaska Island in the Aleutian Island chain today. The weather was windy, and rainy with low clouds. The temperature was 41° F. Dutch Harbor is a container port and is the United States' number 1 port for fisheries landings.

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Approaching Dutch Harbor.

Shortly after passing through the Bering Strait in clear and calm weather, we encountered stormy weather and high seas. The winds have been blowing at 30 to 40 knots and the seas have been 12 to 14 feet for most of our transit across the Bering Sea. The seas have been on our stern, and Healy is a big ship, so despite the rough seas, we have experienced a very comfortable ride.

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High seas across the Bering Sea.

Dr. Brian Calder from UNH is the project lead for data processing and data management. He has been busy, with help from UNH graduate student Giuseppe Masetti, for the last few days organizing and backing up data. Our data has been acquired at significant expense and is very important to the United States’ Extended Continental Shelf project, so careful data management is essential. We have created multiple copies of all our data, and several different members of the science party will be carrying copies back to UNH to ensure that lost baggage or damage does not result in lost data.

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Brian Calder backing up data.

 

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Giuseppe Masetti at his workstation.

During the course of our cruise, we steamed 6471 nautical miles including our transit to Dutch Harbor. Our ECS project accounted for 5416 of those miles. With an average multibeam swath width of 2.5 times the water depth, we mapped approximately 20,000 square nautical miles of the seafloor. We dropped 71 XBTs (expendable bathythermograph), 18 XCTD (expendable conductivity, temperature, depth) probes, took 4 CTDs with water samples, deployed 9 buoys and profilers and drifters, and successfully completed 5 seafloor dredges. All in all, it has been a very productive cruise.

Special thanks to Colleen Mitchell who has been setting up, managing, and posting the journal at UNH!


September 24–26, 2012

While we have been steaming towards Dutch Harbor, we have been busy completing the final data processing and organizing the data for additional analysis ashore. One of our activities has been the creation of Geographic Information System (GIS) products for our analysis work and for sharing our results with the public. Elliot Lim is a GIS specialist from NOAA’s National Geophysical Data Center, and has been our onboard expert for creating the GIS products of the cruise.

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Elliot Lim compiling final GIS products.

 

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GIS-produced map of the cruise track.

On September 24 we passed through the Bering Strait in beautiful calm and clear weather. We could see Cape Dezhneva in Russia on our starboard side and Cape Prince of Wales in Alaska on our port side. Cape Dezhneva was completely snow-covered from the highest elevation all way the down to the sea. A little while later, we passed by Big Diomede Island, Little Diomede Island, and Fairway Rock. Big Diomede is part of Russia; Little Diomede and Fairway Rock are part of the United States.

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Healy’s track line through the Bering Strait.

 

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Cape Dezhneva, Russia.

 

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Fairway Rock, Big Diomede (left) and Little Diomede (right) Islands.

An enormous advantage of multibeam echo sounders over the single beam echo sounders of the past—particularly for scientific mapping—is the ability to see the details in the shape of the seafloor. I was struck by the similarity in shape and structure between these islands and some of the undersea features we have mapped in the course of our Arctic Ocean project. Comparing the multibeam images with the photographs, we can see that the top, the abrupt slope, and the erosional patterns are similar even though the islands are above the sea surface, and the features are as much as 3800 meters below the sea surface.

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Little Diomede and Chukchi undersea feature for comparison.

 


September 22–23, 2012

On Saturday morning we completed our final, and most successful, dredge of the cruise. Our target for this dredge was a small and steep bump 3000 meters deep on the eastern flank of the Northwind Ridge. The Healy’s conning officers and our “dredge master,” Dale Chayes, placed the dredge exactly on the target and pulled it precisely up the 40-degree slope.

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Healy conning officer, Lt.( j.g.) Kris Valdez.

The Northwind Ridge plunges abruptly from a flat-topped plateau at 600 m depth to the seafloor of the Canada Basin at 3800 m depth. This remarkable geologic structure runs continuously for 400 nautical miles along a generally northward trend from the Alaska coastal margin. The dredge brought back several hundred pounds of rock and mud including a large amount of metamorphic rock that had unquestionably been broken off from the slope. The sides of the rocks that were exposed to the sea were covered with thick manganese crust, but the broken sides were fresh and angular. We want to use these rocks to help describe and understand the geology and geological history of the this part of the Arctic, so it is important that the rock we recover is from the local seafloor as opposed to rock that was picked up and carried from shore by ice and dropped when the ice melted.

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Chief Scientist Larry Mayer (with rock), Kelley Brumley (left) and Bernie Coakley looking at the dredge haul as our dredge recovery team rinses and collects the samples.

 

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Freshly broken-off rock from the dredge showing outer manganese crust.

After we got the dredge onboard, we deployed the “Ice Goat,” a meteorological and ocean observation buoy built and monitored by the U.S. Naval Academy. See their Facebook page. In addition to meteorological and oceanographic instruments, the Ice Goat has solar panels that power cameras. When there is sufficient sunlight, the buoy transmits photos ashore every 2 hours. You can see what the Ice Goat is seeing at icegoat.datatransport.org/monitor#icegoat-1/camera0 and icegoat.datatransport.org/monitor#icegoat-1/camera1.

When the buoy was safely launched, Healy turned to the southwest and began the transit to Dutch Harbor. The ship brought an additional engine online and increased from our mapping speed of 12 knots to a transit speed of 15 knots. On Sunday, we passed out of our project area and began the process of organizing and copying our data and packing up the rocks for shipment home. We have had a very successful cruise, acquiring valuable multibeam bathymetry, subbottom profiles, seafloor dredge samples, gravity measurements, and ocean water and ice samples. We’ve also deployed several meteorological and oceanographic buoys and an ocean profiler.

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Launching the Ice Goat.

 


September 21, 2012

Today was a dredging day. We began the day at 4 a.m. with a dredge on the northern edge of the top of Chukchi Plateau, just to the west of Healy Seamount. (We discovered Healy Seamount on our 2003 extended continental shelf mapping cruise. It is a large seamount that rises from 3800 m depth to less than 900 m depth.)

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Today’s dredging sites.

We monitor the dredge with a tension meter on the winch that lowers and recovers the dredge basket to/from the seafloor. We record the tension on the wire before the dredge touches the seafloor. This tells us the combined tension due to the weight of the wire and empty basket. When the dredge lands on the seafloor, the weight of the basket is no longer on the wire and the tension drops. As we retrieve the dredge with the winch, we hope the dredge catches on and breaks off outcropping seafloor rock and captures broken-off pieces. When the dredge catches rock on the seafloor, the additional strain is reflected on the tension meter. If we see a large and abrupt increase in tension followed by sharp drop in tension, it suggests we may have snagged some rock and broken it loose. We saw this pattern of tension changes this morning, but during the recovery we also saw a long period of increasing tension without the sudden drop. This was a sign that the dredge was lodged on the seafloor. Eventually, with the help of some expert ship maneuvering by Healy’s conning officer, the dredge was freed, and returned to the surface with a nice sample of rocks.

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USCG Boatswain Juan Rivera-Montserrate and team recovering dredge sample from the dredge basket.

Our curators spent much of the day cleaning, separating, measuring, photographing, and cataloging the dredge samples. This effort is critical in establishing a good record of our sampling so that these rocks can maintain their scientific value and relevance for the long term.

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Kate McMullen (USGS), Sammy Short (USCG) and Evan McQuinn (NOAA) cataloging the samples. Photo by John Farrell.

The day ended with another successful dredge farther south on the Northwind Ridge portion of the Chukchi Plateau region. Tomorrow will also begin with a dredge.


September 19–20, 2012

We have spent Wednesday and Thursday filling in some of the remaining gaps in mapping coverage on the northern slope of the Chukchi Plateau. On Wednesday, we saw a polar bear mother and cub. They were probably the last polar bears we will see this year. Wednesday ended with a beautiful sunset over the almost complete (9/10 to 10/10) ice cover.

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Polar bear mother and cub. Photo by Lindsay McKenna.

 

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Sunset over the ice.

As we fill in the mapping, we are working toward the south where we have two more dredge sites selected. Today (Thursday), we completed the area where the channel we have been mapping (see September 15–16) seems to spread out and end.

The National Snow and Ice Center reported that the summer ice minimum was reached on September 16 this year, and that 2012 officially set the record for the lowest summer ice minimum ever, eclipsing the previous record from 2007 by a significant margin. The net switch from melting to re-freezing on the 16th corresponds with our observations. Today, as we were traveling south and leaving the ice, we passed through a large band of newly forming ice. One of the characteristic stages of newly forming ice is called “pancake” ice, where the developing sea ice forms in round plates resembling pancakes. We saw quite a bit of pancake ice today.

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Healy passing through pancake ice.

 

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Close-up of pancake ice.

 


September 18, 2012

Overnight, we completed our second dredge. When the dredge came aboard, the basket was full of mud again, but this time there were more rocks mixed in. The rocks were more substantial than those of the first dredge and included rocks with freshly broken surfaces—convincing evidence that these rocks were from outcropping rock. The rocks appear to be basalt, an igneous rock that can be found both on the continents and in the ocean. We can’t say much more about these rocks without doing some detailed analysis in a laboratory ashore. The dredge also contained some thick manganese crusts that form on the seafloor in oceans throughout the world.

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NOAA scientist Evan McQuinn and USGS scientist Kate McMullen recovering rock samples from the dredge haul.  Photo by Bogdan Onac.

During the day today, we tried to do some more mapping to fill in gaps our coverage of the seafloor. We found the conditions very difficult, however. Winter is returning to the Arctic. Areas that were in the marginal ice zone or ice free just a week ago are now covered with new ice. In many areas the new ice surrounds floes of old, multiyear ice. We have found that, surprisingly, the new ice is the most difficult to map in. New sea ice is fairly flexible, and it seems to be flowing under the keel (and therefore under our echo sounder transducer) rather than breaking and floating by on the surface as we pass through it. After spending a few hours trying to acquire multibeam data in these conditions we broke off and headed back toward our 1st dredge site for another try. Unfortunately, the wind and the moving ice created conditions that precluded the dredge. We left the dredge site and resumed mapping. The newly forming ice had thickened up enough in the 6 hours since we broke off that we were able to collect good depth data.


September 17, 2012

Early this morning, the dredging operation we began last night was completed and the dredge brought aboard. The basket was mostly full of mud—not what we wanted—but also contained a dozen or so rocks that we think are from the rock outcropping at the site. There were not any freshly broken edges that would confirm they were broken off by the dredge, and hence of local origin, but these rocks were soft and friable, which suggests to us that they could not have traveled far to reach this location.

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Dale Chayes and Kelley Brumley setting up to monitor the dredging operation.

During the day, we mapped some unsurveyed areas along an indirect path to our next dredge site. This mapping time allowed our dredging team from the Healy crew and the science party to get some rest. While filling in a small, previously unmapped spot along our path, we found a steep bluff on the seafloor, providing us with an additional and totally unexpected potential dredge site. We will consider that site for later in the cruise. In the evening, we arrived at our second dredge site and deployed the dredge. The weather forecast called for significantly increasing winds through the night, but fortunately the wi

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