Saturday, September 22, 2012

A Winter Wind. . .

Yesterday on Facebook I shared a comic that I though very funny.  Here is a link to it:

http://xkcd.com/1111/

There is an associated page or site to xkcd.com, called “What if: ANSWERING YOUR HYPOTHETICAL QUESTIONS WITH PHYSICS, EVERY TUESDAY.”

One of the questions tackled is:

What would the world be like if the land masses were spread out the same way as now - only rotated by an angle of 90 degrees?


Within that page was a mention of the “Bodele Depression” in Chad feeding the Amazon rainforest a huge fraction of the mineral nutrients required for the plants in that fertile area to grow.



I was intrigued.  I had never heard of the Bodele Depression. . . isn’t the Internet wonderful. . . the information available at your fingertips.  I began to research.

The Bodele Depression is the now exposed bottom of a prehistoric lake, about the size of the present Lake Erie in the United States, which largely disappeared several thousand years ago.  The present lake Chad is only 5% the area of this prehistoric lake.


In the winter months, the wind is accelerated and funneled over the Bodele Depression, by the topography of the surrounding land.  The exposed prehistoric lake bottom is very rich in minerals.  These strong winter winds pick up a huge load of dust.


Here is a NASA image of this process:


Due to the very heavy and incessant rains, the soil of the Amazon rain forest is very poor in minerals.  The nutrients for the lush vegetation, must be constantly replaced or the entire ecosystem would collapse.

It is estimated that 40,000,000 tons of dust are anually transported from the Sahara desert to the Amazon rainforest.  Of this huge amount, 40% of this dust is estimated to come directly from the Bodele Depression in Chad.

The Amazon rainforest is 5,500,000 km² in area, about ½  the area of the United States (9,827,000 km²).  The Bodele depression is 44,300 km² in size.  For comparison the state of Indiana in the United States where I live,  is 94,320 km² in area.  Indiana is small.  We are the 38th largest state, and the Bodele depression is just about ½ the area of the state of Indiana.

So to put this in perspective an area ½ the size of Indiana, fertilizes an area ½ the size of the United States. . .from 5,400 miles away!!! This dust travels almost 25% of the way around the earth, before landing in and fertilizing the rain forest:






I live in northern Indiana.  5,400 miles from Indiana is across the width of the United States, and another 1,000 miles beyond Hawaii more than half way across the Pacific Ocean.  The thought of Indiana dust being picked up by the wind, and having an important fertilizing effect in an area 2/3rds of the way to Australia. . . My mind cannot wrap itself around this.

Thinking about it, as important and as amazing as this is, the largest bulk of the dust picked up in the Bodele, never makes it to the Amazon.  I have read no research on this, but it would stand to reason that by far most of the dust load must be dropped long before reaching Brazil, therefore this dust hugely fertilizes not only the Amazon River basin, but indeed much of the entire southern Atlantic Ocean, AND!!! the impact cannot end abruptly with the Amazon rainforest. . . this dust must in some measure continue on past South America, could this dust on occasion possibly travel into the near reaches of southern Pacific Ocean?. . .The reverberations of happenings in a small dusty valley in Chad. . . a winter wind in a small African valley may indeed be felt around the entire world.

This world of ours is so fearfully and wonderfully made. . . .

I love Psalm 139. David was speaking of himself, but my mind is brought to considering his words in context of the entire earth. . . indeed how the entire universe is ’fitly joined together’ (Ephesians 4:16) :


Psalms 139:9-16

If I take the wings of the morning, and dwell in the uttermost parts of the sea;  (10)  Even there shall thy hand lead me, and thy right hand shall hold me.  (11)  If I say, Surely the darkness shall cover me; even the night shall be light about me.  (12)  Yea, the darkness hideth not from thee; but the night shineth as the day: the darkness and the light are both alike to thee.  (13)  For thou hast possessed my reins: thou hast covered me in my mother's womb.  (14)  I will praise thee; for I am fearfully and wonderfully made: marvellous are thy works; and that my soul knoweth right well.  (15)  My substance was not hid from thee, when I was made in secret, and curiously wrought in the lowest parts of the earth.  (16)  Thine eyes did see my substance, yet being unperfect; and in thy book all my members were written, which in continuance were fashioned, when as yet there was none of them.

What other mysteries await our discovery?  In what other ways does a gust of wind. . . or a raindrop. . . or a falling star. . . or a cloud. . .or a word. . .or a hug. . .or an act of kindness. . .or a testimony. . . or a prayer. . .seemingly unimportant in of itselves have an impact felt around the world. . .

I love you my God. . .
I thank you my Lord. . .

1 comment:

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