Mooring on the way up – and mooring on the way down.

With a CTD and LADCP (current meters mounted on the CTD) we can understand where the water is flowing and what its temperature is right now that we are here – but we will also be able to see what happens when we are back home already. We deploy the instruments on so-called “moorings” that stay in the ocean and measure while we are gone, and that we will come and pick up next year or the year after. I have never been in the Amundsen Sea before, so I don’t have moorings to recover right now, only new ones to deploy. But my Swedish, English and Korean colleagues do have moorings in the water – and we are getting more and more excited as we are coming closer to the position where those moorings were deployed two years ago! Karen holds a hydrophone over the railing and down into the water. Then she keys in the releaser’s special code. Far away, deep beneath us on the sea floor, the mooring waits to hear from us – and finally, now, after two years in the ocean, it can reply “here I am!”. Karen types in a second code which means “let go!”, and right away she gets the reply from the mooring: “I’ve let go, I am on my way up!”. All of us are excitedly watching the sea – keen to be the first person to spot the yellow buoy.

–       There it is! There it is!

The crew has deployed a small boat to go and fetch the mooring – they know exactly what to do, they have done it many times before.

A couple of hours later all instruments are on board and we are working hard. All data needs to be downloaded to our computers and stored to hard drives. Later, the instruments are turned over and get new batteries and software. Tomorrow they are going back into the sea!

The Koreans weren’t lucky this time round; their first mooring had broken off a bit above the sea floor and therefore they could only recover the releaser and a couple of thermometers. Their other mooring was completely gone – it was probably dragged away by a large iceberg. But the last three came up exactly as planned!

Photo: Nicole Waite
Photo: Nicole Waite

Yesterday we had a meeting with the crew and technicians to talk through what my mooring looks like and to decide how to best deploy it. The crew speaks little or no English*, therefore the meeting was held in Korean – only every now and then I was asked something in English. For almost an hour it sounded pretty much like this:

ㄻㅊ널촘ㅈ괴ㅓㄴ모거모 ㅏㄱ mooring ㅓ로ㅕ추마 ADCP ㅕ루  멍로 ㅏㅕ고러ㅏㅓ Shackleㄷ ㅣ찰머놀ㄹ러ㅏmooring 몬염ㅍ뒤곤?mooring름 ㅡㅐㅐA-frame 갸ㅜㅎ 멀촘너 .

Photo: Nicole Waite
Photo: Nicole Waite

I took my time and carefully prepared my instruments and tools – trusting that it would be several days before my moorings should go out into the water. The Koreans had four moorings that should go out first. But it got really windy and the waves got higher and higher – and the captain gave the order to stop working on deck because it was too dangerous… And this messed up the whole work schedule! We steamed westward at full speed, to the western part of Getz ice shelf. There is more ice there, and hopefully less waves, so we can use the time while the weather is bad to steam there instead of just waiting around for the weather to get better until we can deploy our moorings. So now it is all of a sudden my last mooring that shall go out right now… and therefore, I unfortunately don’t have time to write more right now!

*I asked La, one of the oceanographers who speaks excellent English, how he learned the language. All the others who speak English well did their PhDs or studies aboard – but I knew La hadn’t done that. After a while I found out that during his studies, he once a week talked in English with those people in Korea who want to talk to you in English for free: Jehova’s witness and Mormons! “But I am still a Buddhist, I just wanted to learn English and couldn’t afford a private teacher…”

Do the Math! Moorings and time series


Archimedes principle

What floats in the dead sea?