Climbing Masts and Oceans

March 21, 2010 Noontime position: 24 25.510 S, 99 28.891 E

A few days ago we had our first climbing lesson, to learn to scale one of the tall ships vertigo-inducing masts. Meanwhile, our boat is also climbing - UP the ocean. In fact, on this trip so far, we’ve already descended around 30 feet, and are now beginning to climb again, another 100 to go before reaching Mauritius. How is that possible? I wondered - isn’t sea level a more or less constant height around the world – i.e. zero?

Meet Bert Vermeersen one of the chief scientists on board, taking extremely accurate, vertical GPS measurements on sea level height. Which is apparently quite difficult to do. Bert found Marcus and I on deck in the early morning, struggling to do some sit ups while the boat rocked and rolled about. We quickly abandoned this exercise in futility, and chatted with Bert instead.

“Believe it or not, sea level can actually vary by as much as 300 feet around the world” Bert explained, “depending on the relative depth of the ocean, the force of gravity, and differences in topography. The earth is a flattened elipse rather than a spherical globe – equator to equator the earth is 20 miles longer than at the poles. These differences in sea level height are measured with respect to the ellipsoid.”

And so, although the indigo blue expanse surrounding us looks perfectly flat, we are slowly, gradually inching our way up a marine mountain, at a pace so slow that only Bert’s high tech measurements will notice the change.

Climbing the mast on the other hand – this is a change noticeable enough to send my heart rate soaring! After a basic safety 101 from one of the deck hands, we donned our harnesses and scampered up the mast, as we’ve been watching the crew do enviously for days. The view from atop is breathtaking. This is now a daily must!

AND THE QUEST FOR THE PERFECT HIGH SPEED TRAWL CONTINUES
For the last few days, a group of around 10 eager men, lead by Marcus and Haico, have been wrenching, bolting, testing, and retesting a space age looking steel-torpedo device, rigged with an underwater camera and a long net. The idea was to create a high-speed trawl, with a camera that would capture footage along the way. The first try had the contraption bouncing and diving along the surface like a lovable robotic dolphin. The footage was mesmerizing – a crystalline underwater seascape – but the device still spins wildly. And so Marcus is back in the workshop, welding another prototype. We all wait anxiously.

Still, we’ve had a chance to trawl twice so far – both times yielding a trawl full of Portuguese Man O War (ouch!) and one or two plastic fragments. We’re still far from the accumulation zone.

TALKING PLASTIC WITH THE BEAGLE CREW
Last night, Marcus and I gave the evening lecture, a daily routine. We all gather in the dining room for the Captain’s 7:00 address – he gives a brief talk on the next days wind and weather patterns, shows a slideshow of photos from the day, and then one of the guest scientists on board shares their research. We’ve heard presentations on core sample drilling in Antarctica and the Artic from paleoclimatologist Henk Brinkhuis (www.iodp.org), seen a film tracing Darwin and Wallace’s parallel findings on natural selection, and last night, we were given the floor. We shared our research with Algalita and 5 Gyres on plastic in the world’s oceans, to a room of scientists who seemed genuinely intrigued by the issue. And in a few days, the evening program will be dedicated to plastic pollution solutions. We’re very interested to hear what comes out of the brainstorming session – full report to come.