Fire Cloud...
An irregular marking on the exterior of Native American pottery: usually resulting from burning fuel coming in direct contact with the vessel during firing

Friday, 16 July 2010

Oligotropic Lakes

Western Brook Fjord, Newfoundland

We're on the west side of Newfoundland, about 240 miles north of the ferry port. It's an approximately equal distance north to the short ferry over to Labrador.

Last night we had planned to go to a pub for mooseburgers and music. Newfoundland has the highest concentration of moose in the world. There are four moose per square kilometer in moose suitable habitat. These all came from four moose imported here about a 100 years ago. We haven't seen any yet. When we arrived at the pub we found that it required tickets and was sold out (filled with old people from an RV caravan). We found a little local restaurant that served us white wine and a lovely deep-fried codfish. I plan to eat more cod in the future.

The Western Brook Fjord is a narrow channel carved by waves of glaciers in billion year old igneous rock. The walls reach a height of 2,000 feet even after a billion years of being ground down. It is believed that about 40 glaciations have filled the fjord only to eventually retreat. You reach the boat tour of the long fjord by a 3 kilometer hike though bogs and marshlands. The blue star iris very common along the trail this time of year.

The last glacier melted about 15,000 years ago. At first it was a true saltwater fjord, but it became landlocked about 9,000 years ago when the land near the sea rose again after being relieved of the weight of billions of tons of ice.

The fjord is now fresh water, oligotrophic and distinguished by nutrient deficiency, as opposed to productive, eutrophic lakes, with an ample or excessive nutrient supply. Oligotrophic lakes are most common in cold regions underlain by resistant igneous rocks (especially granitic bedrock). These lakes are oxygen rich. The water of Western Brook is so clear and pure that it is a poor conductor of electricity.


1 comment:

  1. you did not say why you are demoted...
    i thought you were doing ok....sil

    ReplyDelete