Friday, March 5, 2010
Circle South America: Alter Do Chao Brazil
Dear Family and Friends,
Ola from the Amazon River, deep in the heart of Brazil. We entered the mouth of the Amazon on Tuesday morning. It is just latitude 52 minutes south of the Equator and it was already 88 degrees at 7:00 AM. The delta is over 200 miles wide and has several islands we needed to navigate around, including one that is the size of Switzerland!
We passed Santarem, Brazil which we will visit when we come back down the Amazon and by 3:00 PM we reached our first stopping point at a small village named Alter Do Chao at the mouth of a tributary to the Amazon called Rio Tapajos. There was honestly not much there but a little town square with a small Catholic church, an open-air bar, where the Skol beer was really cold and a gorgeous beach with palm frond roofed huts. The high today was 99 degrees and 98 % humidity. Good GAWD it was hot. The jungle and rain forest here is really thick and I hope you like the pictures.
Several million years ago, after the continent of South America split off from the continent of Africa and started its trek west across the Atlantic Ocean, this huge shelf of land was slightly tilted and rainwater drained from the east edge of the new continent to the west. When this huge land mass started bumping up against the Pacific Teutonic plate, the collision forced a huge upheaval of the western edge and formed the Andes mountain range. This geologic change blocked the river flows traveling to the west. The subsequent backup of water, over time, formed a huge inland sea of fresh water which ended up covering nearly two thirds of the Amazon basin. Remember, that would be an area which is about the same size as the 30 western states of the United States (everything west of the Mississippi River)! This inland sea, one of the largest in the world at that time, lasted for about a half a million years. Then the Pacific plate started moving underneath the continental shelf, or more accurately, the South American continental shelf rode up over the Pacific plate, and the entire opposite tilt of the continent caused a reversal of water flow from the west to the east, like it is to this day. This caused the inland sea to drain into the Atlantic, leaving behind the Amazon River and over 2000 rivers and tributaries which are now the Amazon River Basin. The Basin contains the largest rainforest in the world, which, by the way, is responsible for producing over 30 % of the world’s oxygen. Think about that, no Amazon rainforest, no more us.
The rainforest is a separate eco-system all by itself and one would think that with its dense vegetation the topsoil would be several yards thick. It is not. The topsoil in the rainforest and surrounding jungle averages only three feet and much of it is as little as 2” deep. Below that is rich clay which averages 60 feet in depth, the remnants of the layer upon layer of compacted sediment left behind from the inland sea. It is a very delicate system which is under constant attack from cattle ranchers and soybean farmers, timber companies and developers who all need more land to expand their lucrative businesses. They are cutting down the rainforest at a rate of 100,000 hectares (about 2.4 acres per hectare) per year. Since this rampant elimination of the rainforest began in the later part of the 19th century it is estimated that 18 % of the rainforest has been depleted and the rate increases every year.
Brazil’s government, in cooperation with dozens of international organizations (like our guest lecturer Jean Michel Cousteau’s), governments and private companies, have put legislation and agreements in place to slow the destruction of the rainforest but still huge chunks of it are lost each year to over development, pollution and accidental as well as deliberately set fires. It is hugely important, not just to the nine countries whose indigenous wildlife, human well being and economies are directly linked to the health of the Amazon Basin but to the entire world’s ecology and environment, to preserve this unique and critical eco-system.
We will continue up the Amazon to Boca da Valeria and will arrive at 7:00 Amon Thursday. Until then, God Bless you all.
Jud and Vicki