By the Catlin Arctic Survey team
WWF is supporting the research of the Catlin Arctic Survey. This year’s research includes an expedition across the ice, as well as an ice base, both in the far north of Canada. The main purpose of the mission is to gather data on the changing Arctic Ocean currents.
At the Catlin Ice Base conditions are cooler than those faced by the expedition (-37°C) but reasonably calm weather has made setting up camp easier than expected. All 19 tents are erected, and over the week the operations team has put its efforts into preparing two sampling ice holes.
Each sampling hole is a full-day job, as Ian Wesley, Field Expedition Manager, explains:
“To create our square sampling hole without getting too wet or too cold we have to drill down into the ice but stop just before we break through to the ocean below. We drill four holes quite close to each other, knock out the thin sections of ice between them and lastly break through to the water below. The ocean rushes up to fill the space – stopping just short of the top of the ice. It might sound simple but given the ice is between 1.7-2 metres thick at the base, it’s a back-breaking day’s work.”
Ice Base scientist Dr. Helen Findlay explains what the first sampling hole will be used for: “In the first hole we have set up an instrument that measures current speed and direction of flow. This instrument is called an Acoustic Doppler Current Profiler (ADCP) and hangs just below the ice taking continuous readings of the seawater as it passes by. This will give us an idea of some of the physical properties of the seawater – the different currents that flow through the area, any tidal regimes or vertical flow. We’ve put a tent over this hole, just to help slow down the hole from refreezing. Every day we’ll have to chip out the inch or so of ice that has reformed.”
“The second hole is for our main sampling of the seawater. We will use this hole every four days or so to take samples of seawater from different depths. We will also be deploying instruments that will make profiles of the seawater temperature and salinity, as well as light profiles and measurements of fluorescence (an indication of the different particle that are present in the water – either live organisms, like phytoplankton, or just organic matter that has been released and is floating around in the currents).”
From today the scientists will be settling into a routine of sampling and analysis. Although the Ice Base team has only been on the ice for a week they’re now set up and ready to go.