Our Arctic core samples keep turning up great surprises! If you'll recall from a previous journal (August 13, 2010 Piston Coring), we struck gas hydrate in the bottom of one of our cores in the Beaufort Sea. At the core analysis workshop at the USGS Coastal & Marine Science Labs in Menlo Park, CA earlier this month we discovered that some of the core sections from that site also had numerous clam shells. Since each core is only about 8 cm wide, that would mean that this part of the sea floor is pretty dense with clams! Many were intact with both top and bottom valves (shells) in place indicating they lived there instead of being carried there later. But what would clams live on in this cold, dark, deep water??
Clams recovered from a sea-floor core sample indicate a cold seep...
Once each core sample was split, a host of descriptions, tests and sampling protocols awaited the mud inside. To keep organized, a sampling plan was mapped out for each core taken in US waters on our cruise (Canadian-side samples will undergo similar analysis early next year in Nova Scotia.) On the sampling plan, each core section is shown with its assigned International Geo Sample Number (IGSN, which works like a trackable serial number) and the places where each core was trimmed (in centimeters, measured from the top.) From these measurements the length of each trimmed section can also be easily determined. The map also indicates samples taken from the core catcher & core cutter, as well as external sediment scrapes analyzed for microfossils. Blue dots show the plan for pore...
One of the reasons I so enjoyed and appreciated the 2010 International Continental Shelf Survey last summer was because of the wide range of science that was undertaken on the cruise. Every day I could see something new and learn much about geology, oceanography, meteorology, climatology, ice studies, biology, chemistry, physics, navigation, computer systems, instrumentation, marine sampling technology, and the gear and techniques used to travel in, survive, and understand the Arctic. Still, the mission had three priorities and all other science had to be done in a way that wouldn’t interfere with the primary objectives. The main goal of the cruise was to collect seismic data. Secondary to that was collecting high-resolution bathymetry data via multibeam sonar. These two data sets...
I'm checked in at the San Francisco Airport waiting to board my plane back home. It has been a very busy, productive week for me with the last four days learning many aspects of sea-floor sediment core analysis. I was privileged to help the team with several core analysis jobs, getting my hands dirty but always smiling. I'm going to have a series of journal entries describing much of what we studied from two arctic coring sites we visited last summer on the Healy, but for now I'm a little too knackered to say much more in any kind of articulate fashion. So I'll leave you with a lovely shot of a split core sample taken in the Beaufort Sea- what do you think you can find in the mud upon close inspection?
That's all for now- Bill
The top part of one of the core samples taken in the...
This entry is dedicated to the Marine Mammal Observers (MMOs) from our cruise: Justin, Sarah, & Kwasi!
I'm currently on another PolarTREC journey, this time to California in anticipation of a core sample workshop at the United States Geological Survey offices in Menlo Park, California. We took several deep-sea core samples while in the Arctic Ocean, which were promptly trimmed into manageable lengths, sealed, labeled, recorded, and then put into a walk-in refrigerator. When the Healy returned to its home port in Seattle this past October, chief scientist Brian Edwards drove up to retrieve the cores and ship them in a refrigerated truck to Menlo Park, where they have been awaiting the detailed analysis that happens in labs equipped with the right gear. I am thrilled to be involved...
It is with mixed feelings that I report being back on dry land. This morning I caught a helicopter ride off Healy to Barrow, Alaska. I'm very excited to get back home, see my family, and begin to get caught up at school three weeks into the semester. But I'm also a little sad that the cruise is over. I'll miss the amazing sights, great camaraderie, and fantastic science that went on every day I was aboard the Healy. We covered a lot of the Arctic Ocean on our cruise. I traced the major legs of our trip using Healy's map server and found we covered over 5000 nautical miles in our travels since leaving Dutch Harbor on 2 August. That breaks down to an average distance of about 142 nm a day and a speed average of about 6 kts.
Tracklines of the United States Coast Guard Cutter Healy on our...
Speed 13 knots (kts)
Course 249°
Location Southern Canada Basin, 73.25° N, 149.98° W
Depth 3773 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
The answer to yesterday's riddle (What grows like grass on our railings at night but gets mowed down by Arctic sunlight? ) is frost. We've had some spectacular overnight growths of hoarfrost crystals, sometimes well over an inch long. It grows best on windward side railings and lines when the night has been foggy and breezy.
A lovely garden of hoarfrost crystals, over an inch long, growing on a railing aboard Healy.
A boat hook aboard the Healy provided an ideal place for spiky hoarfrost crystals to grow overnight.
A line to one of the RHI boats sports fresh hoarfrost crystals after a foggy, breezy night on...
Speed 4 knots (kts)
Course 180°
Location Canada Basin, 75.91° N, 136.15° W
Depth 3560 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
I can think of two likely mechanisms to move fairly large sediment like pebbles far offshore. Normal deposition quickly drops out coarse material like pebbles at or near shore, with no chance of them drifting far from land. But enormous mass wasting events known as turbidity currents (kind of like giant underwater landslides) can move sediment vast distances as they pick up speed down steep continental slopes and spread out over abyssal plains. However, a classic turbidity current-derived deposit shows graded bedding with the most coarse debris settling out first, followed by ever finer sediment in an upward direction...
Speed 4 knots (kts)
Course 295°
Location Eastern Canada Basin, 76.79° N, 133.68° W
Depth 3420 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
The Beaufort Gyre rotates clockwise in the Arctic Ocean, circulating ice along with it. As the ice pack heads towards Greenland, some diverts along the east coast and out of the Arctic via the Labrador Current, moving southward into the North Atlantic Ocean. But ice passing along the north side of Greenland and towards the Queen Elizabeth Islands gets slowed down and held longer, constricted by the land. This gives it a better chance of remaining for multiple years, freezing thicker every winter. Ice that is carried by the Beaufort Gyre away from the Queen Elizabeth Islands into the Beaufort Sea and other...
Speed 0 knots (kts) (Stopped for core sampling and CTD cast)
Course N/A
Location Southeast Canada Basin, West of Prince Patrick Island 76.53° N, 128.62° W
Depth 2061 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
Here's a sea floor profile heading east from the Canada Basin, up the Banks Rise, Banks Slope, and Banks Shelf, and onto Banks Island.
Sea floor profile west of Banks Island, Canada generated by Healy's map server.
While there is significant vertical exaggeration (if drawn to scale, the sea floor wouldn't rise nearly that steeply), you can see the differences in the relative steepness of a rise (which begins the transition upward from the abyssal plain), a slope (the steep transition from deep to shallow water) and a shelf (shallow, gently...
Speed 8.4 knots (kts)
Course 107°
Location Southeast Canada Basin, West of Banks Island 74.41° N, 132.58° W
Depth 2933 meters
TODAY'S JOURNAL:
A snowy first of September, 2010 on the USCGC Healy in the Canada Basin.
The first of September brought even more snow this morning, this time with enough accumulation to morph many of the ship's deck surfaces from black to white. I was enjoying the view from the bridge when I got into a conversation with SN Evan Burgeson about the names of things around the ship. There are seemingly endless specialized objects, parts, and equipment aboard a ship and many have colorful names. The ones with animal-related names caught my fancy, and I decided to put together a virtual scavenger hunt for you to try from a little photo safari I went on this...
Speed 8.7 knots (kts)
Course 135°
Location Canada Basin, 75.31° N, 139.38° W
Depth 3669 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
Since pressure increases by about 1 atmosphere for every 10 meters of water depth, the cups experienced about 380 times more pressure when they were at 3800 meters deep than they do at sea level.
TODAY'S JOURNAL:
Bill Schmoker, aided by communications officer Holly McNair, calls in to Centennial Middle School for his PolarConnect event on 31 August 2010 via satellite phone from the wardroom on USCGC Healy. Photo by Dale Chayes.
I woke up to a fun sight today- snow falling outside! Snow flurries continued on and off throughout the morning, and a little even accumulated in protected spots of the ship. Pretty neat for...
Speed 15.5 knots (kts)
Course 208°
Location Canada Basin, 78.06° N, 136.33° W
Depth 3684 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
Prior to canning, freezing, and refrigeration sailors on long voyages had to rely on other methods to keep food supplies secure. Once fresh produce and meat ran out, the main ways they had to keep a supply of food for months or even years were salting, curing, drying, and carrying livestock. Meat, for example, was heavily salted in brine and kept in barrels. Enough salt would prevent bacterial spoilage but rendered it inedible. To make it edible again it was soaked and boiled to get at least some of the salt out. Cured foods like hard cheeses and smoked sausages can be made to last for a while. Other staples like...
Speed 4.4 knots (kts)
Course 237°
Location Northeastern Canada Basin, 80.34° N, 124.99° W
Depth 2798 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
There is little or no sunlight in the Arctic winter and so seeing sun dogs then can be difficult.
Since windy days can keep the air above the Earth's surface mixed that is not good for seeing mirages. But calm days can promote surface layer formation (either warmer or colder air) that can lead to mirages.
TODAY'S JOURNAL:
Every Saturday the ship has some special events to help keep morale up. In addition to a round of bingo and the evening hangar movie, a different department each week takes the lead in cooking dinner to give the galley crew a break. Our turn came up last night, and we made a pizza...
Speed 5.5 knots (kts)
Course 137°
Location Northeastern Canada Basin, 81.10° N., 120.09 W.
Depth 2945 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
By retrieving the topmost layers, a box core sample gives us information about the most recent events on the sea floor. (According to the law of superposition, younger layers are deposited on top of older layers.)
A dredge should be dragged up slope. This way the dredge will stay in contact with the sea floor. If it is moving down slope or along an undulating slope it can be pulled off the sea floor and into the water.
TODAY'S JOURNAL:
I like to do a lot of my journaling and photo/video editing up on the bridge. It has a great view of the ship's surroundings, I can hear radio communications between...
Speed 0.3* knots (kts) (Currently stopped to make a CTD cast)
Course 66°
Location Northern Canada Basin, 81.79° N, 128.36° W
Depth 3569 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
A seamount is an underwater mountain that rises above the surrounding sea floor but doesn't reach sea level. If it reached sea level it would be an island!
During the coring operation we were stopped in the ice but the GPS indicated we were moving over the sea floor at 0.5 kts. This is because the ice pack was drifting that fast, taking us with it as it went. Most ice in the Arctic is dynamic, moving due to winds and surface currents. The exception is 'fast' ice. This doesn't mean that fast ice is moving quickly but instead means it is fast to shore, or locked in place...
Speed 0* knots (kts) (*backing and ramming through thick ice.)
Course 123
Location Northern Canada Basin, 82.27° N, 135.51° N
Depth 3637 meters.
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
Polar Bears can eat snow or ice to get fresh water. Even sea ice becomes fresh over time as tiny pockets of unfrozen brine work their way down and out of the ice.
We are very far north now where longitude lines are getting pretty close together, so our longitude changes fast when we are moving. Across the globe, latitude lines are parallel and always the same distance apart while longitude lines converge at the poles.
TODAY'S JOURNAL:
Good news- the Louis successfully repaired their propeller shaft bearing and we met up with them last night. Our rendezvous point will...
Speed 6.7 knots (kts)
Course 312°
Location North Canada Basin, 81.9° N, 136.10° W
Depth 3693 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
Even a 420-foot long icebreaker like the Healy can get stopped by the ice. The first thing to try is to back up and then use the open path ahead to gain speed for another try. This is called backing and ramming. Icebreakers have special rudders that are designed to withstand going back through ice. If backing and ramming doesn't work the icebreaker can try to back up far enough to find another path around the obstacle. Occasionally, though, an icebreaker may find itself stuck due to pressure squeezing ice in on it. In order to gain a little maneuvering room one trick is to have one propeller turn clockwise and...
Speed 6.4 knots (kts)
Course 28°
Location Northern Canada Basin, 80.93° N, 136.79° W
Depth 3780 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
Strong earthquakes can produce damaging seismic waves. But earthquakes also give us an insight into the internal structure of the Earth. Earthquake-generated seismic waves can pass through or be absorbed by different layers deep inside the Earth. By analyzing patterns of waves received at seismic stations around the world after earthquakes we can measure the thicknesses of the crust, asthenosphere, mantle, outer core, and inner core.
Scientists also use core sampling and drilling to find out what is beneath the sea floor. While core sampling can recover samples from many meters under the sea floor, drilling...
Speed 8.4 knots (kts)
Course 56°
Location Canada Basin, 79.06° N, 144.18° W
Depth 3811 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
The Canadian Coast Guard helicopter, a MBB BO 105, carries special gear for flying out alone over the Arctic ice. See which of your safety ideas match with the Canadian Coast Guard's!
First, this is a twin-engine helicopter so if one engine fails the aircraft can still fly (if not back to the ship then hopefully at least to a safe landing spot.) The skids have inflatable floats in case the ice isn't thick enough for an emergency landing. The pilot and passengers wear inflatable life jackets with a laser flare in one pocket and a personal locator beacon in the other. We wear exposure suits (aka Mustang Suits) as well...
Speed 4.7 knots (kts)
Course 55.6
Location Canada Basin, 78.35° N, 150.98° W
Depth 3829 Meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
The surface water temperature during my freezing water demo was about -1.1° C (about 30° F.) The key to this water being liquid below the 'freezing point of water' is its salinity. On the screen shot of our water monitoring system below you'll notice that the when I did the demo the surface salinity was about 26.2 PSU, which equates to .262% or 26.2 parts per thousand. (This means there were 26.2 grams of salts dissolved for every 1000 grams of water, which is actually pretty low compared to world-wide averages closer to 3.5% salinity for the Earth's oceans.)
Screen Capture of the Healy's sea water monitoring system...
Speed 9.2 knots (kts)
Course 316°
Location Canada Basin, 76.80° N, 147.41° W
Depth 3821 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
The deepest features in the Earth's oceans are oceanic trenches. Some exceed 10,000 meters deep, with the Marianas Trench in the western Pacific Ocean exceeding 11,000 meters (nearly 7 miles) at its deepest point.
The multibeam sonar projects out at an angle to each side of the ship. As water depth increases the sonar beam spreads out farther, mapping a wider swath. We are currently mapping a swath about 10,000 meters wide in water about 3800 meters deep.
TODAY'S JOURNAL:
This morning we did a deep-water CTD cast, recording conductivity (to determine salinity), dissolved oxygen, fluorescence (to determine chlorophyl...
Speed 3.8 knots (kts)
Course 80.1°
Location Eastern Canada Basin near Northwind Ridge, 76.34° N, 152.11° W
Depth 3840 meters
SPECIAL FEATURE DISCUSSION:
(see previous journal for the questions.)
When the sky is clear, visual satellite images give a fantastic look at ice conditions but days like that are exceptions rather than the rule in the Arctic. Radar can penetrate the typical fog and overcast, so RadarSat imagery is more reliable than visual satellite images for evaluating ice conditions.
(For our icebreaker race problem, remember: Nautical Mile = nm, Nautical Miles Per Hour = Knot = kts)
The Louis had 30 nm to cover at 4 kts. Thus, her trip to the ice edge would take: 30 nm / 4 kts = 7.5 hours
So the Healy had 7.5 hours to beat the Louis to the ice edge 120 nm away. So we...
Speed 4.1 knots (kts)
Course 289°
Location 75.78° N, 155.59° W, Canada Basin near Northwind Ridge
Depth 3483 meters
SPECIAL FEATURE DISCUSSION:
(see 8/17/10 journal for the questions.)
As you can see on the information plaque, each lifeboat has a capacity of 25 passengers. With 8 lifeboats on the ship that means there is room for 200 people aboard the lifeboats. We currently have 112 people on board (Coast Guard crew, science team, and visitors) so there would be plenty of room for everybody in the worst case scenario of loading lifeboats.
Barrow, Alaska is the northernmost city in the U.S. Nearby Point Barrow, at the end of a spit of land a few miles north of Barrow, is the northernmost point of land in the United States.
TODAY'S JOURNAL:
As we continue to cruise deeper into...
Today is the first day of school for my students so I wanted to take a break from the regular format of my journal entries to welcome them back for another great year at Centennial Middle School! I made the video below over the summer, knowing I'd miss the beginning of school for the first time in my 18 years at CMS. I'm very pleased that Mr. A could fill in for me while I'm on this expedition. My students are very lucky to benefit from his experience and talents as a teacher.
In addition to the many posts yet to come I'd encourage folks to skim through past journals to see what's been going on so far on the cruise. I'd also suggest you check out the Ship Talk and What Is The Arctic videos.
I'll be back to my regularly-scheduled programming tomorrow.
Quyanaqpak (pronounced khoo'-...
