Saturday, December 29, 2012

Smooth sailing on a Drake Lake (December 18-20, 2012)


The sea gods and goddesses heard my prayers, a Drake Lake it is!

So, what is the Drake Passage and why is it such a big deal?  The Drake Passage is the name of the body of water passing between the southern tip of South America and the Antarctic Peninsula.  With no landmasses to slow the flow of the water and wind as the Atlantic Ocean meets the Pacific Ocean, the conditions are notoriously rough and stormy. For the first night, we had smooth sailing as we passed through the Beagle Channel, with continued favorable conditions as we entered the open ocean around 3:00am on December 19.  The sudden, yet slow rocking of the ship often waking everyone from their slumber (only for most to fall back asleep as the rocking on the ship certainly lends to snoozing).  In this brief moment I sent out a little prayer to the sea gods and goddesses for a smooth crossing, or Drake Lake.  For it is no fun being stuck in one’s cabin seasick for two days.  Based on the weather reports we stood a great chance of having a calm crossing; with a storm brewing off of the southern coast of Chile just after we departed we were able to stay ahead of this weather system and ended up having a beautifully calm crossing with sunny skies to boot!
Profile of the Drake Passage (http://en.wikipedia.org/wiki/File:Drake-Passage_profile_hg.png)

Making our way through the unusually tame “Roaring 40os” and “Furious 50os” we were greeted by Black-browed Albatross, Pintado Petrels, Light-mantled Albatross, Southern Fulmars, Diving Petrels, Southern Giant Petrels, Antarctic Petrels, and a number of Prions darting about the bow of the ship.  Though the air temperature was about freezing, many of us spent time out on the deck watching and attempting to photograph these graceful fliers, many of which are only ever seen at sea. 

Light-mantled albatross

 Early in the morning on December 20 we crossed the Antarctic convergence (typically at about 60oS), the band of ocean that separates the Southern Ocean from the Atlantic and Pacific.  The Antarctic convergence is not necessarily something you can see (though at times is associated with a dense bank of fog), but you know you have crossed it based on a rapid drop in air and sea temperature as you enter the Southern Ocean.  In addition to a drop of a few degrees in water temperature, the ocean also becomes far more saline (saltier).  It is in this location that we leave behind the fauna and flora of the temperate part of the Southern Hemisphere and enter the realm of polar species.

Approaching the South Shetland Islands in the late afternoon we sail over the Hero Shelf/Shackleton Fracture Zone, a region of the open ocean known for abundant wildlife as shallower depths and upwelling bring increased productivity.  Increased productivity meaning more food!  It is here that we see our first humpback whales, far off in the distance, and pick up some of the largest flocks of Pintado Petrels I have ever seen, dancing on the water just behind the ship.  For surely that was a good omen as we sailed on to our first destination in the Antarctic Peninsula, Half Moon Island.
Just a few of the hundreds of Pintado (or Cape Petrels) following the ship this evening.

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