Posted by: adorsk | June 30, 2007

Midway

Right now there are about 1500 meters of water below the ship, and there is no wind. The sea looks like a mirror.

Today is the midpoint of our cruise. 15 days ago we left Reykjavik, and in 15 days we’ll return. My sense of time has changed since being on the ship. Sometimes the days seem to fly by. I’ll write in my journal before going to bed and wonder where the day went.

Other times it seems like there’s no time at all, especially since land has gone out of sight. We’ve been offshore for the past four or five days, nothing but sea to the horizon. Since there’s no night, it feels like I’m living in infinity.

Just thought we’d drop in…

There was one especially exciting event this week: a helicopter drop from the Icelandic coast guard. You may remember from my last post that our primary magnetometer had gone down due to a leaky tow cable, leaving us with only our backup Maggie. The magnetics data is crucial for this cruise, so we wanted to make sure we had a back-up.

Now, it helps that one of the chief scientists is the president of the Icelandic geology association. He was able to arrange for the Icelandic coast guard to conduct a ‘training mission’ in which they would drop off a new magnetometer cable. Apparently geologists are kings in Iceland. The man has connections.

So, two days ago the Icelandic coast guard flew in to do a helicopter drop. It was spectacular. The helicopter hovered 25 meters or so above the deck, beating up the sea into a mist. It’s hard to describe how powerful a helicopter is. It pounds out a constant ‘wap-wap-wap-wap-wap’ that drowns out all other noise. Its blades spin to a blur. Its tinted windows and bulk make it look like an indeterrable predator. The best analogy I can think of is a giant flying blender-shark.

The Icelandic coast guard knows their stuff. P, one the Icelanders on board, says they often rescue fisherman who get caught in rough weather. First they lower down a weighted rope to the deck of the ship. This rope acts as a guide line for another rope that is controlled by a winch. The coast guard man rapelled down on this rope, followed by our magnetometer cable. When the coast guard man went back up, he went upside down, and then rotated up once his feet were on the side rails. Imagine looking straight down into the sea while you’re hauled up 25 meters.

They also picked up our Bosun, P, who had to get his foot checked out by Doctors in Reykjavik. (we found out later that P is ok).

The whole thing was pretty amazing. I’ve got to admit, you get to see some cool stuff in this job.

Helicopter 1 HeliLift heli_upsidedown

More on Science

i thought I’d write more about why we want to measure gravity and magnetics. Gravity lets us know what the rock really looks like on the sea bottom. Sometimes sediments and clay cover up geological features, in the same way that a snow drift covers up a boulder. Most sonar depth sounders aren’t powerful enough to ‘see’ through the sediment. So instead we measure the force of gravity to figure out how much mass is in the sea bottom. Rocks are denser than sediment, and so will exert slightly stronger forces of gravity. We can measure slight differences in gravity to figure out what the true shape of the underlying rock in the sea bottom.

Magnetics tell us when portions of the sea bed developed. You may know that the Earth’s magnetic poles have ‘flipped’ in the past, so that North became South and vice versa. When we look at the local magnetic force from rocks in the sea bed, we can figure out how the poles were oriented when those rocks were formed. This lets geologists make timelines for how the seafloor developed.

I think this is all quite clever.

Steaming On

That’s pretty much it for now. We continue to have excellent weather, and our data has been coming in nicely. Hopefully things will continue to go well. Thanks for reading.

Miscellaneous Pictures

last_land spiral shadows bird_flock

Chicken of the Sea, from our weekly cookout

chicken_of_the_sea

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Responses

  1. 7-1-07/Alexander –
    Regarding the “new” island of Surtsey, you might share with your mates on board the Knorr, your father’s observation regarding the birth of that island. After my graduation from college in 1964 (shows you how old I am) I travelled to Europe that summer as a graduation present from my parents, flying via Loftleider (Icelandic Airlines). While everyone else on the plane was asleep, but for the pilots and me, the pilots were excited about seeing something as we approached Iceland and invited me into the cockpit to see what they were seeing (obviously in the days before no access, locked cockpits). They pointed out to me in the ocean off the southwest coast of Iceland (if I remember correctly) one of the most spectacular sights I have ever seen – indelibly etched into my memory. I saw a moment during the birth, not of Venus, but of Surtsey – a volcanic eruption taking place with fire, ash, and white and red-hot lava flowing into the sea creating an enormous amount of steam, fortunately blowing away from us, while there were icebergs floating around in the nearby ocean. It was truly quite a sight. We subsequently landed in Iceland and spent a day being taken around the area, sun brightly shining at our 2 AM arrival.
    Dad

  2. 7/02/07
    Alex,
    You are right…when you are in a place where the sun shines almost 24 hours you don’t get tired or sleepy. When we were in Anchorage a few years ago the sun was still shining at midnight and we were ready to keep on moving and doing. We thought “how can we go to sleep when the sun is out and there is so much to see”.
    In case you don’t remember, I am your mother’s 1st cousin on the Parmet side.
    I enjoy reading about your adventures and am learning a lot about that part of the world from your notes and pictures.
    Judy in Michigan


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