Sea-Level Rise, Subsidence, and Wetland Loss

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  • Опубліковано 26 гру 2024

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  • @MISHA12314
    @MISHA12314 8 років тому +2

    Agree with most of this video. Couple things stand out to me as being questionable. I'm saying this because i've lived on the Mississippi delta most of my life. Climate change affects me directly. 1) Of course, sediment deposits build up the marsh. From venice down river, there are no levees. A lot more flow passes through head of the passes than previous generations saw, but silt accumulation continues to be a major problem for shipping, which requires constant dredging. 50 years ago, noone noticed that the delta was subsiding. Problem I have with this, and this video, is that in spite of a tremendous load of sediment from venice south, the marsh continues to sink close to the river and outside the levee system. Sea level rise would not affect the sinking land inside the levees in venice.... and since the river hasn't run over the land inside the levees in a hundred years or so, most of the organic matter that was going to decompose below soil water level has long since done so.
    Add to this, that I've seen the marsh and sea shore water bottoms rise and fall, based on nothing that was reasonable. Sand bars would move when the river was low... and remain for a year or so, then revert to the past locations not based on river levels.. Channeling the river course is not a solution to the problem. 2) Most of the ice in this world is floating. Floating ice is sea level neutral. Reason for this is displacement of ice is equal to it's total weight, not its volume. A lot of the ice in this world has been frozen for mellennia. Snow compacts, and forms glaciers, which have always moved. When there is less snowfall, glaciers slowly go away. Maybe the whole problem with believing sea level rise is attributable to ice is simply a long term drought in the higher northern climes. We really don't know. 3) Something no one has mentioned regarding sea level rise, is the temperature of the earth itself. A very small change in the core temperature of an 8000 mile diameter earth could result in a major sea level change. Do the numbers for coeffecient of expansion of rock. Sounds dumb... but it really isn't. Please accept this in the spirit in which it was written.