Thursday, February 4, 2010
Circle South America: Chilean Fjords
Dear Family and Friends,
We have spent the last two days cruising through the Chilean Fjords in the southern tip of this long narrow country on the west side of South America. For you Map Heads we are currently at 50°49’46” S latitude and 73°53’20” W longitude on a south heading of 29.8 degrees on a course taking us to Punta Arenas, Chile. This will be our jumping off point through the Drake Passage and across the Strait of Magellan to the continent of Antarctica.
The Chilean Fjords are a series of over 2,000 islands, 927 channels, 2,800 rivers and streams and innumerable waterfalls that have been carved by glaciers over tens of thousands of years. There are over 1,000 glaciers all stemming from the Southern Ice Fields, a huge snow and ice pack covering hundreds of square miles from Chile on the Pacific side to Argentina on the Atlantic side of the southern tip of South America. It is a region called Patagonia, and is one of the least populated areas of South America, the portion we are in now being only accessible by ship or boat. The population density is said to be lower here than in the Sahara Desert.
The mountains here in this region of the Andes plunge dramatically straight down into the ocean which has filled in these gorges as the glaciers have receded. These heavily forested, starkly beautiful mountains are literally rising out of the sea as the Pacific Teutonic plate continues to merge with the South American shelf, slowly sliding underneath the shelf and raising the land mass.
On Tuesday we took a large catamaran over to the Laguna San Rafael; a large, glacially carved lake with the huge San Valentin Glacier entering the lake from the south. Glaciers are literally rivers of ice which move at varying rates down the mountainsides to sea level. Depending on the global climate, glaciers advance or recede based on how much snow falls at their source. In the case of glaciers in this part of the world, snowfall on the Northern Patagonian and Southern Ice Fields has been diminishing over the last several years thus causing most of the glaciers being fed from them to be receding. This is not because of “global warming”, merely temporary climate change which occurs naturally in cycles of varying lengths.
Glaciers form when areas like the Southern Ice Fields get hundreds of feet of snow annually and this snow becomes super compacted as layer after layer builds up. The snow becomes very dense ice at the bottom and it is ice with no air in it and is very pure. It is clear ice but it looks blue as light penetrates and all but the “fastest” color, blue, is filtered out. Gravity then starts the glacier moving, carving out deep canyons in its wake and grinding the rock into gravel and dust called moraine. Not all glaciers reach the sea but those that do lose large chunks of themselves through a process called “calving”. The San Valentin Glacier is calving at a rate of 3 meters, roughly 9 feet, per day. While we were there, which was only for about 20 minutes, two massive chunks of ice separated from the face and plunged into the sea, creating a sound almost like thunder and a huge wave as they crashed into the sea.
Our catamaran got within 100 yards of the San Valentin Glacier and is quite spectacular being 197 feet tall at its face. It is one of 19 glaciers originating from Monte San Valentin, at 13, 314 feet it is the highest peak in the Southern Andes. This glacier is the closest in latitude of any on earth to the Equator and anchors the top end of the Northern Patagonia Ice Field. This ice field is the largest mass of ice outside the polar regions.
Yesterday we continued our tour of the fjords and cruised up Iceberg Sound Fjord to visit the Iceberg Sound Glacier. Even bigger than the San Valentin, this glacier had a massive 250 foot tall face and we were told that near its source it is nearly 1,000 feet thick. At the base, where there was recent calving, the ice looked a deep sky blue.
Tomorrow we tour to Otway Sound and a large penguin reserve for our first up close and personal look at these intriguing animals. I will cover that on my next blog update. Until then, God bless you all.
Jud and Vicki