LARISSA - LARsen Ice Shelf System, Antarctica, a NSF-funded project.

LARISSA - LARsen Ice Shelf System, Antarctica, a NSF-funded project.
We are conducting an integrated, multi-disciplinary field program to address the rapid and fundamental changes occurring in the Antarctic Peninsula region as a consequence of the abrupt collapse of the Larsen B Ice Shelf in the fall of 2002. A profound transformation in ecosystem structure and function is occurring in coastal waters of the western Weddell Sea. This transformation appears to be yielding a redistribution of energy flow between chemoautotrophic and photosynthetic production, and to be causing the rapid demise of the extraordinary seep ecosystem discovered beneath the ice shelf, providing an ideal opportunity to test fundamental paradigms in ecosystem evolution.

Sunday, January 24, 2010

Danco Coast Fjords

14-21 January We have spent the past week along the Danco Coast on the west Antarctic Peninsula (64 to 66 degrees south latitude), working in fjords carved by massive glaciers. Our primary LARISSA Project goal here is to hug the coast across the peninsula from our geological and glacial studies sites, hoping to send teams of geologists by helicopter over the mountains to their work areas. This requires clear flying weather simultaneously on both sides of the Peninsula (a 6000 ft mountain range), which occurs infrequently. The weather has been cloudy for the last week, precluding helicopter operations, but allowing us to study the oceanography of the Danco Coast fjords.

The NB Palmer dwarfed by a tidewater glacier calving into Flandres Bay, a fjord on the Danco Coast.

Map of the Antarctica Peninsula, showing the fjords of the Danco and Graham Coasts.

The Fjords of the west Antarctica Peninsula are oceanographically extremely interesting because they contain “tidewater glaciers”, i.e., glaciers calving icebergs directly into the ocean. In addition, the Antarctic Peninsula fjords have only opened relatively recently (in the last few thousand years), i.e., they represent early stages in the transition of fjords from ice-choked polar to ice-free temperate ecosystems. The oceanography and seafloor ecology of of fjords have been intensively studied in Norway, Canada and Alaska, but these are warm fjords compared to the Antarctic Peninsula and contain rapidly melting glaciers or no glaciers at all. The marine ecosystems of the Antarctic Peninsula fjords are likely to be fundamentally different (e.g., they have relatively little input of glacial meltwater and rock flour) and yet they have been little studied. Thus, while waiting to complete our helicopter operations, the oceanographers on board the NB Palmer are conducted studies of the ecology of the Peninsula Fjords.

Massive front of tidewater glaciers emptying into Barilari Bay.

Humpback whales feeding in Flandres Bay, some only meters from the bow of the ship!

Abundant brittle stars, sea spiders, spoon worms, and starfish on 2 square meters of seafloor at a depth of 600 m in Flandres Bay fjord.

After studying two fjords near Anvers Island, we are now heading south to Barilari Bay, a fjord south of Cape Garcia on the Graham Coast. If the weather clears, we hope to send glaciologists on to the top of the Peninsula to emplace GPS units to measure glacial movement. However, since the weather has remained cloudy, preventing helo operations since we arrive on the west side of the Peninsula more than one week ago, we are quite worried that we can complete the helicopter transfers. At least we can explore the ecosystem of another fjord, working with truly breathtaking backdrops.

Conducting a plankton tow from a zodaic inflatable boat with a Flanders Bay glacier and mountains as backdrop.

1 comment:

  1. Uau!, really cool pic guys. The animals on the bottom look a lot different from the other sites in WAP. Good job! Angelo.