Cruise Log HY01-01 (by Dr. Darby)
Sunday, June 26, 2005
The science crew and some of the Coast Guard crew departed Healy today via helicopter to Barrow. Most of the science crew flew out of Barrow the next day with hopefully fond memories and lots of data.
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Saturday, June 25, 2005
Today was the last working day of the cruise and a very busy day indeed. We took the eight and last jumbo piston core in the early afternoon near the head of the Barrow Canyon in 88 meters water depth. The target was an expanded Holocene section of up to 20 meters thickness. We recovered a little more than 15 m of sediment, probably all Holocene with a small amount of pre-Holocene sediment, potentially pre-Quaternary sediment at the bottom of the core. The trigger weight core recovered a little over 2 meters of sediment and the multicore taken immediately after the JPC recovered 30 cm of the surface sediment from the bottom. No plankton haul was made because the last one was adequate for characterizing this area. After the JPC, TW core, and multicore were curated and stowed in the refrigerator onboard Healy, general clean-up began. Everyone pitched in to clean the labs, stow gear in the ship hold, and clean berths in preparation for our departing the ship on Sunday and the arrival of the next science crew for leg HLY05-02. In retrospect, our slow start precipitated by being stuck for four days was more than made-up by everyone's hard work during the remainder of the cruise. We collected over 115 meters of JPC and this far exceeded expectations. Hopefully there is a great sediment record to be worked on for the future. We will not know exactly what was recovered as far as a paleoclimate record for perhaps several more years when we have
a chance to thoroughly examine the sediment recovered.
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Friday, June 24, 2005
After surveying all night along the continental shelf margin, we positioned for another piston core in 400 + meters. Unfortunately, we missed our target due to some delays as we drifted faster than expected into shallower water. Instead of coring several meters of Holocene mud and then several glacial deposits, we hit overcompacted glacial till immediately below only a couple meters of Holocene mud. This till was apparaently overcompacted by former ice bergs that grounded in this area. The stiff mud resulted in some tense moments in the winch control room when pull-out strain reached nearly 20,000 lbs. Normally pull-out for this depth and core (rigged for 15m) would be about half this. Another multicore, CTD hydrocast (water sampling), and plankton haul were successfully completed as well. We will move closer to Barrow tonight and survey the head of Barrow Canyon for a good core site to sample a thick sequence of Holocene sediments.
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Thursday, June 23, 2005
We located another expanded section of possible Holocene (last 10,000 yrs.) sediment from the sub-bottom profiler in 700 meters water depth at 72 deg. 30.7' N and 157 deg 1.5'W along the continental slope north-northwest of Barrow, Alaska. We rigged for 18 meters (60 ft.) and recovered about 16 m of sediment, including a nearly full 10 ft gravity trigger core. A multicore with 7 tubes and 1 Niskin bottle was deployed soon thereafter and nearly 70 cm of the upper sediment column was recovered. The science crew and the Coast Guard Techs were up late with a plankton haul and CTD hydrocast that was completed before 1 am Barrow time. Both were successful. Thus far we have recovered 6 piston cores and a total of 85 meters of core not including multicores and trigger weight cores.
Today was another beautiful sunny Arctic summer day for the most part with occassions of fog and temperatures just below freezing. Between 3 and 5 pm there was ice liberty for all of the crew and all except essential watches enjoyed some frizbee, soccer, football and refreshments on the ice. This was also a great photo opportunity and just be chance, we were setup on an open lead in the ice and someone noticed some dirty ice across the lead from the ship so Dr. Bischof was transported by launch to collect some samples. It turned out to be one of the most concentrated sediment in ice seen thus far.
Ice Liberty--A Day at (on) the Ocean Photos
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Wednesday, June 22, 2005
Today was a full day of coring. We collected a Jumbo Piston Core along the slope of a small canyon in about 540 meters of water followed by a multicore to sample the upper 50-70 cm at the sediment water interface. Then we drifted southwest with the pack ice into slightly shallower water and retrieved a second piston core. Both piston cores were rigged for 18 m and we recovered about 13.5 m in the first and nearly 16.5 m in the second. Both cores had full penetration but contained water pockets in the lower 1 to 2 meters due to water being pulled into the core liner by the speed of the core barrel entering the sediment and water being sucked into the barrel faster than the sediment by the piston. Together with the multicore between them these two piston cores will hopefully provide a long record with relatively high resolution. The sub-bottom profiles suggest that the two cores can be correlated and probably overlap for a continuous long record. We can only determine this after opening these cores and determining the age of the sediment layers in each core. Pore water and sediment parameters were collected from the multicore. While the coring crews worked a 16-18 hour day, several others had to wait until the cores were retrived to begin a CTD hydrocast to collect water samples, including temperature and conductivity (salinity) with depth. A vertical plankton haul was also made to depth intervals of up to 250 m. The folks doing these measurements did not finish until after 2 am. The bottom acoustic surveys including sub-bottom profiles were collected overnight as we broke ice to the southeast. We will position ourselves for a survey of another canyon and then the head of Barrow Canyon before heading to Barrow on Saturday.
June 22 Photos
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Tuesday, June 21, 2005
Our position: Lat. 72.50 N, Long. 158.22 W
Weather: Wind ENE 9 kts, Air Temp 1C, 34F
We collected our third jumbo piston core today. We rigged for 15 m and got full penetration in about 540 meters water depth and excellent recovery. There was a 2 hour delay before the multicorer could be deployed following the piston core and during that time we drifted into much deeper water and steeper bottom slope. This resulted in poor recovery of the multecore with only about 20 cm in one side and zero in the tube opposite. This was followed by another successful vertical plankton haul, primarily for the upper 100 m water depth. We surveyed all night along the continental slope toward Barrow Canyon to the southeast.
After three glorious days of sunny weather in the mid 30's, the high pressure to our north has brought slightly cooler air into the area and with the abundant open leads here, evaporation is rapid, resulting in fog. Still the Arctic is fascinating with the broken ice up to 1.5 meters thick and patches of open water, with or without the foggy conditions that add a touch of sureality to our view.
June 21 Coring Photos
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Monday, June 20, 2005
Our position: Lat. 72.54 N, Long. 158.26 W
Weather: Wind: SE 8 knots, Air Temp 2.7C 37F
The recovery from the first core taken on Sunday the 19th was nearly 13.5 meters, which was remarkable considering that a coupling gave way, probably upon entry into the bottom and completely separated when we began to haul the piston core out of the water. The core immediately bent where the PVC core liner was exposed and eventually broke at this location. Since the core was only rigged for 15 meters, losing a mere 1.5 m was remarkable and a tribute to the core tech, Pete Kalk and the MST crew from Healy. The MST crew are the Coast Guard techs assigned to work the winches and do everything needed on the deck to assisi the science mission. Today we rigged for 22 m because the seismic data indicated a thick sequence of relatively soft sediment, but the ice drift carried us into deeper water by the time the core reached the bottom and into sediment much harder than the seismic data indicated farther up slope. The core bent about 30 degrees after penetrating about 11m and impacting a very stiff clay layer. Amazingly, the core was able to penetrate a muddy sand and gravel layer near the surface and then through nearly 11 m of stiff clay before hitting the extremely stiff clay and stopping. This core will help to understand the origin of these valleys on the continental slope and how the sediments were deposited in them.
After the piston core was secured onboard, no easy task with a 70 ft core whose lower 30 ft is bent, the hard work of pulling PVC pipe out of the steel core barrel began and took nearly 4 hours of coaxing with come-alongs and crew muscle. We recovered more than 11 meters.
Immediately after the piston core was secured on deck, a plankton net was deployed as we drifted. A good sample was obtained by raising the net several times before closing it. A hydrocast in 1400 m water depth was not successful when the trigger failed to trip the niskin bottles properly to close them with water samples from various depths.
Surveying commenced at about 2 am ship time and continued until 10 in the morning.
June 20 Working Photos
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Saturday, June 18, 2005
The big news is that "Ice Station Healy" is on the move. We broke out around 1700 hr. after nearly a day of spraying fire hoses on the large ice block that was wedged under our stern. By melting the top, it shifted up, out of the water and allowed us to backup a little. After several hours of back and forth we finally started making headway in this multiyear floe that had us imprisoned. We then set a heading north, northwest to some potential coring targets on the continental slope near 72.9 deg N and 158.43 deg W, about 23 miles away and expect to reach this sometime around noon Sunday.
Flight operations again were successful in spotting and sampling dirty ice about 20 miles north of where we were beset. During our record setting "ice camp" of 4 days, we did drift west, northwest over 13 miles. Unfortunately, most of the time the ice trapped under the ship blocked the acoustic signals from the multibeam and we did not collect much data about the bottom bathymetry nor sub-bottom.
The movie special of the week, shown on the big screen in the helicopter hanger Saturday night was "Million Dollar Baby". About 40 people enjoyed both movie and popcorn.
Weekend working photos
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Friday, June 17, 2005
Melt ponds are rapidly developing everywhere and new cracks are appearing so we have high hopes of breaking out of "Ice Camp Healy". Winds are predicted to increase from 10 to 25 kts overnight and that too may cause some shifting of the pack that has us pinned-in. Everyone is anxious to get under way and collect some core. Morale is still high and everyone has found something to keep themselves busy. There have already been two science talks, one by Dr Margo Edwards on the Alvin dives to mid-ocean ridge smokers (hydrothermal vents) in the equatorial Pacific and one by Chief Scientist, Dr. Dennis Darby on "Arctic Ice Drift, Past and Present: Implications for Climate Change". Captain Oliver has assigned a detain to man two fire hoses on the stern to melt a large ice block that dives at an angle under the stern and is apparently pressing against both rudders. After about six hours, they are having an impact because not only is the pressure relaxing but our 3.5 degree list to port is half that since they started. Healy depends on speed to ram thick floes by backing and ramming. If we can't backup, we have little hope to breaking the multiyear floe in our path. Wen large slabs of this ice broke and slid in behind us on Tuesday evening, we lost that backup ability. The dirty sea ice samples collected yesterday have melted and we will be ready to decant the meltwater tomorrow when the sediment settles-out completely. There appears to be lots of sediment in these initial samples of dirty ice.
Ship tour photos
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Thursday, June 16, 2005
Our situation remains unchanged despite a reprive in the wind from the southeast.This wind has pushed ice against the starboard side and we are now listing 3.5 degrees to port.This is a minor inconvenience in that some of the drains are not working well.The helicopter recon flights went off today and Dr. Greg Cutter was on the first flight looking for dirty ice to the northeast of our position.While he didn't find any, Dr. Guillaume St-Onge was lucky enough during the second flight to the northwest and brought back several bags of ice with sediment.This sediment will later be analyzed to determine where this ice formed.We revved the Healy's engines to maximum this afternoon to see if we could affect the ice ahead of us because we no longer can backup.While the gush of seawater behind the ship was spectacular, causing a river of flow over the icepack, the ice didn't budge.
Dr. Margo Edwards gave the first science talk for the ship's crew tonight entitled: "Voyage to the bottom of the sea".She presented work that she did in the equatorial waters with Alvin dives on the mid-ocean ridge there and spectacular shots of deepsea smokers.
Today's photo collection
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Wednesday, June 15, 2005
The wind continues from the east-southeast and there is little relief from our predicament. There are some bright spots as the multibeam is working great with the lack of ice noise from Healy. This changes suddenly around 3 pm when ice is pushed against the starboard side and Healy lists 3.5 to port. While not much this is certainly noticeable. At this point ice must have lodged beneath the ship blocking the transponders because all acoustic data ceases.
Even flight operations normally scheduled for reconnaissance has to be cancelled because of the wind strength and direction, not permitting safe launching of a helicopter. This also scrubbed the scheduled flight for Dr. Greg Cutter who had the first flight looking for dirty sea ice so that the sediment could be sampled to determine where this ice originated. This is done later by analyzing the Fe oxide grains in the sediment trapped in the ice when it formed. The chemical composition of these grains is used like a fingerprint to match each grain to previously analyzed grains from around the margins of the Arctic Ocean.
Bear watch photos
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Tuesday, June 14, 2005
Work continued with preparing Healy for coring and other science operations. The giant piston corer had to be rigged and the multicorer readied. Core liners for this multicorer are used to extrude the 50-70 cm long cores into. These plastic tubes are cut to length and then sliced in two lengthwise. The two halves are then taped back together so that after the sediment from one the eight permanent multicorer tubes are pushed up into one of these precut liners, it can be easily opened by cutting the tape and running a wire through the sediment. The plankton nets and porewater sampling devices had to be setup and this was mostly completed by dinner time when we became lodged in a floe of multiyear ice that compressed behind us preventing the Healy from backing to ram it's way through. This was precipitated by an unfortunate wind direction that pushed the ice perpendicular to the cut being made by Healy.
Today's cruise photo see here.
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Monday, June 13,2005
Helicopter transfers from Barrow to the Healy for the Science Crew and some of the Healy crew that were rotating off the ship began around 10 in the morning and by 5:30 pm everyone was aboard. There was a meeting to discuss ice conditions and due to relatively heavy ice in the area of our initial coring station northeast of Barrow, we decided to head northwest toward some potential interesting features along the slope that could yield high sedimentation rates. The primary objective of this cruise is to obtain sediment cores from such areas in order to develop detailed paleoclimate records for the last several tens of thousands of years. Initial preparations for our first station began with moving science gear from the hold to the science labs.
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