I had my big pre-expedition planning conference call the other day (it went an hour and 40 minutes but seemed to fly by!) Kristin & Janet at PolarTREC coordinated 8 of us on the line, efficiently going over all of the little details as we near the final approach. In addition to Kristin & Janet I spoke with Caroline Singler, a NOAA Teacher at Sea who will also be on the cruise. I'm really excited that there will be another teacher on board- I'm sure we'll have lots to share. Brian Edwards and Helen Gibbons from the USGS filled in lots of details about the scientific mission and ship-board life. Liz McMahon from NOAA offered her support, and Robbie Score from CH2M HILL Polar Services handled personal equipment and travel logistics. I'd like to thank all of them for "tuning in"!
It looks like I'll be traveling from Denver to Dutch Harbor on 30 or 31 July. We can board the Healy on the afternoon of 1 August, and the ship is slated to sail on 2 August. We should take about 5 days to transit the Bering Sea, stopping to take a piston core on that leg of the cruise. We'll then pass through the Bering Strait into the Chukchi Sea, our first taste of the Arctic Ocean. The Chukchi is relatively shallow and mostly island-free, wedged between Alaska and Siberia north of the Bering Strait. We'll then turn eastward, heading towards the Beaufort Sea and our anticipated 8 August rendezvous with the Canadian icebreaker Louis S. St-Laurent, aka "The Louis", (pronounced Looey.) We hope to have time to dredge and core on the Beaufort Slope on the way to our meeting. The Beaufort Slope is the seafloor's transition from the shallow Chukchi Sea to the relatively deep Beaufort Sea.
From there, the nature of the cruise depends on the amount of the ice we encounter. We will be seeking geologic and oceanographic data to help establish the full extent and nature of the continental shelf lying north of the U.S. & Canada. One way to map seafloor geology from a ship is by using reflection seismology, sending penetrating sound waves from compressed air explosions down and analyzing their return echos from layers lying beneath the bottom of the ocean. The Louis is equipped to record seismic data by using an air gun to generate the seismic waves and towing a long line of sensitive microphones in the water behind it that record the reflected energy. Our job while in this mode is to clear a path through the ice so the Louis will have clear water for their seismic gear. Another method used to characterize the seafloor is by using sonar data. Sonar also relies on sending and receiving sound waves and the Healy has two types of sonar systems that will collect detailed bathymetric data; Multibeam and Chirp. Finally, we will physically collect seafloor samples when possible, both by coring and dredging. If there is a lot of ice our ability to take seafloor samples will be limited, but if there is more open water or light ice we will have more time for this task, possibly separating from the Louis for portions of the cruise. Additionally, there will be scientists studying ocean water chemistry (particularly ocean acidification) and looking at ice conditions, possibly deploying ice buoys during our trip. I'll explain each of these types of studies in more detail down the line but this hopefully gives you an overview of what we'll be doing! Here's a draft map that Cruise Chief Scientist Brian Edwards put together in Google Earth of priority areas for sampling to give you a general idea of where we'll be operating. The water is the Beaufort Sea, and the land at the bottom is northern Alaska and Canada (the little vertical section of yellow line is their land border.)
Draft Map of Sample Priority Areas for International Continental Shelf Survey.
On 6 August we are scheduled to swap crews by helicoptering off the Healy to Barrow, Alaska. On each round trip folks will be flying onto the ship for the next scientific expedition as we depart to get back to our "regular" lives. It is starting to feel like the trip is just around the corner now- I've still got stuff to do before departure but now that we're in July it is pretty exciting to know I'll end the month in Alaska!
That's all for now! Best- Bill