Since pushing off the dock at Seward around 13:00 yesterday, we’ve been transiting at 10-11.5 knots towards station 201, which we should reach around 3-4 a.m. tonight. During the transit, we’ve been getting our sea legs as the ship rolls and pitches in the moderate sea swell, eating tasty food that galley cooks Mark I and Mark II have been treating us to, and getting ourselves organized and prepared for the on-rush of deck work that will begin soon. Below are some photos from yesterday and today. Scroll to the end to get so see the bonus video of Dall’s porpoises!
View of Resurrection Bay as we left the dock at SewardMan-overboard rescue drill with observers on the stern pointing towards the dummy in the water as the Sikuliaq’s small boat motors in for the rescue.The dummy from the man overboard drill resting after being saved by the ship’s crew.Sikuliaq’s 1st Mate John Hamil gives us a safety briefing prior to our departure from Seward.As party of the safety briefing we got to try on our immersion suits, which are big floppy versions of dry-suits. They are designed to keep you buoyant and insulated and we were told you could survive for about a day floating in the cold water in one of those. Ideally, if the situation non-ideally arose, you would only need the immersion suit for when swimming from say a sinking vessel towards a life raft. Left to right: graduate students Christine Chesley, Tanner Acquisto, Brandon Chase and Scripps technician Jake PerezGraduate student Janine Andrys, ship’s tech Tony, graduate student Li Wei and EM technician Goran Boren ready to abandon ship during the safety drill yesterday.Marine tech Jake Perez explaining how to assemble an ocean-bottom EM receiver.Jake and Chris teaching the graduate students and cruise volunteers how to assemble an ocean-bottom EM receiver.Bosun Paul in the ship’s winch room pointing to the far drum holding about 9 km of the .680″ coax cable we will use with our deep-towed EM transmitter (the near drum holds the ship’s trawl wire). Out of view is a large level winder and a traction winch that are part of the winch system. The .680 cable goes off the drum, through the level winder and traction winch, then up to a block above the main deck and finlly out through a sheave attached to the A-frame on the stern.The .680″ coax cable drum. The cable holds a coaxial conductor, which we make electrical contact to through the slip rings in the small stainless steel cylinder on the right. The slip rings allow us to transmit power (in our case about 2000 V) from our top side power supply to the cable on the rotating drum by using brushes to make electrical contact with conductors on rotating rings. Power then goes through the cable and on down to the deep-tow transmitter system (which you will see in posts in a few days from now).
Here are some photos from yesterday showing the RV Sikuliaq and some of our science team preparing equipment. Right before leaving the ship for dinner in town, we were treated to a mother and baby humpback whale swimming around right next to the ship. Today we have some safety meetings in the morning and then will depart for sea sometime around lunch time.
We’ve all arrived in Seward, Alaska, and boarded the RV Sikuliaq today. We need to prepare the OBEM receivers, set up the lab, terminate the deep-tow cable and make other preparations before the ship pushes off the dock tomorrow. The map below shows our four planned controlled-source electromagnetic (CSEM and magnetotelluric (MT) survey profiles and some of the other past, present and upcoming geophysical surveys in this region.
Planned survey map showing four trench crossing EM profiles with 42 ocean bottom EM receivers (white dots) per profile. Grey lines show past active source seismic profiles and red lines show upcoming multichannel seismic profiles to be collected by another group this summer. Red circles show ocean-bottom seismometers currently deployed for the Alaskan Amphibious Community Seismic Experiment.
