On Rivers
If the upstream part of a river thaws first (possibly because it flows away from the equator), and the ice gets carried downstream into the still-frozen part, the ice can form an ice dam and flood the areas upstream of the jam. This occurred during the 2009 Red River Flood and the 2009 Alaska floods. After the ice dam breaks apart, the sudden surge of water that breaks through the dam can then flood areas downstream of the jam. While this usually occurs in spring, it can happen as winter sets in when the downstream part becomes frozen first. Where floods threaten human habitation, the blockage may be artificially cleared. Ice blasting using dynamite may be used, as well as other mechanical means.
Read more about this topic: Ice Dam
Famous quotes containing the word rivers:
“Blessed is the man that walketh not in the counsel of the ungodly,
nor standeth in the way of sinners, nor sitteth in the seat of the
scornful.
But his delight is in the law of the Lord; and in his law doth he
meditate day and night.
And he shall be like a tree planted by the rivers of water, that
bringeth forth his fruit in his season; his leaf also shall not wither;
and whatsoever he doeth shall prosper.”
—Bible: Hebrew Psalm I (l. I, 1–3)
“Poor shad! where is thy redress? When Nature gave thee instinct, gave she thee the heart to bear thy fate? Still wandering the sea in thy scaly armor to inquire humbly at the mouths of rivers if man has perchance left them free for thee to enter.”
—Henry David Thoreau (1817–1862)