Exploration and science often go hand in hand. Since the early days of the polar exploration, science including land and sea survey have almost always been on the agenda. It was totally normal for a crew to sail towards the poles, shoving ones way into totally unfamiliar frozen territory until boats were forced on top of the ice for months, even years and only at that point did their work really begin. It is unbelievable that in the 21st century parts of this world are still uncharted such as in Northern Baffin Bay and Smith Sound where we just were working.
Since man and boat were a team, to determine water depth, a man could stand at the bow of a ship, or in a little rowboat ahead of it and drop a line with a weight attached and count how many fathoms (6 feet is 1 fathom) lied below once it hit bottom. Today we use sonars. A sonar sends a ping (sound wave) at a known rate that travels to the sea bottom then back and measures the depth by recording the time it took for the ping to take its trip. When you know speed and time you can determine distance. Onboard the Ault we have a depth sounder recording depths down to 2100 feet. Our work this season includes hydrographic reconnaissance giving today’s hydrographers (ocean surveyors) a heads up before they set out to these regions to create comprehensive 3D underwater maps using multi-beam sonars. Countries with coastal waters work hard to create accurate nautical charts so that each depth and each position is accurate to well under a meter. There are many things that go into the accuracy of a depth and a position, one has to consider the rise and fall of the tide and the how a ping can falsely detect the bottom at major temperature and salinity changes. These locations where sound can get distorted and struggle to record the real sea bottom are called haloclines and thermoclines.
At 78 degrees north we sailed into an area that had little hydrographic (depth and shoreline feature) information. Our boats GPS (Chartplotter) showed us literally sailing off the charts and on to land! Islands were not where they were charted, at times 0.25 miles off, there were also large charted islands that did not exist at all. In the early days of polar exploration, beginning in the 1800’s, mariners confused ice and clouds for land and distant mountains. Today, in the few uncharted polar places of the world icebergs could be accidentally digitized (drawn) by a mapping agency cartographer looking at a satellite photo on their computer, mistaking it for land.
In order to follow through with our primary research focus in that region, finding the warm salty Atlantic water and determining how far North it goes we had to simultaneously survey the depth. Before heading inland to survey 5 glaciers and their associated fjords we found the warm water miles offshore on our first try with a high of 1.1 degrees Celsius at 700 feet deep. We verified its presence and by searching for it 3 more times before reaching our furthest North location. The warm water layer narrowed and cooled as it headed further North so it was hard to find the further North we went. Satisfied with our results so far and surrounded by ice it was time to start heading south for other areas to study.
Take a look below at this week’s Bonus Guest Scientist Blog written by Clark Richards of RBR Ltd., his organization developed the devices we have been using to study both salinity and temperature of the polar and Atlantic Ocean water.