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USGS CMG InfoBank: Sea Level Drop

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Comment: 15:37 - 16:41 (01:04)
Source: Annenberg/CPB Resources - Earth Revealed 23. Glaciers
Keywords: "J. Lawford Anderson", "Ice Age", glacier, landscape, coastline, ocean, "sea level", continent, stream, erosion, river, "glacial melt", discharge, flood, valley, inlet, harbor, estuary, sediment

Our transcription: The last ice age left striking marks still visible on the landscape.
Coastlines the world over shifted because much of the water that had been available to the oceans was frozen instead.
We see the sea level drop as much as 300, 400 feet below present day positions. With that dropping of sea level, all the streams of all the continents of the world, being that much higher above present day seas and needing to move down toward the seas, started eroding, digging down, running faster.
So all the rivers begin to run faster throughout the world.
There was more erosion due to streams.
As the last ice age ended, melting icecaps discharged vast quantities of water into the ocean, flooding the lower valleys of these streams.
Many have become inlets, harbors, or estuaries.
Some have filled with sediment becoming flat, coastal valleys.

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Page Last Modified: Thu Oct 31 04:27:48 PDT 2013  (chd)