
Roaring glacial melt under the bridge to Kangerlussiauq, Greenland - DoreenMichele
https://twitter.com/Laurie_Garrett/status/1157015875276464129
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cbkeller
Lot of silt in that water! There has been some interesting debate recently on
the efficacy of glacial erosion under the Greenland ice sheet -- and more
broadly whether or not global average erosion rate has increased due to
northern hemisphere glaciation over the past few million years. One recent
estimate [1] suggests:

> _We find that, although runoff from Greenland represents only 1.1% of the
> Earth’s freshwater flux, the Greenland ice sheet produces approximately 8%
> of the modern fluvial export of suspended sediment to the global ocean._

[1] [https://doi.org/10.1038/ngeo3046](https://doi.org/10.1038/ngeo3046)

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adrianN
I wonder what effects on the ecosystem it will have when the ice sheet is too
small to introduce comparable amounts of sediment into the ocean.

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cbkeller
That's an interesting question. Fe and P are probably the most relevant
nutrients that are abundant in suspended glacial rock flour. Since Fe3+ is
pretty insoluble in seawater, the suspended (vs. dissolved) load might
actually matter -- wind-blown dust would be the #1 competitor. The first
relevant paper I found suggests the dust still dominates [1], but it was
clearly enough of a consideration for them to write a paper about it. And
sometimes the wind-blown dust is actually glacial rock flour [2], so the plot
thickens!

[1]
[https://doi.org/10.1007/s10533-015-0091-6](https://doi.org/10.1007/s10533-015-0091-6)

[2]
[https://doi.org/10.1029/2010GL046573](https://doi.org/10.1029/2010GL046573)

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whycombagator
That is a staggering volume of melted ice.

I am interested to know how this melt’s volume compares to other years/days on
record though.

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scarygliders
Read down that tweet thread. Such facts and figures are published there.

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whycombagator
Glancing over the thread I see lots of related data but nothing specific to
Kangerlussiauq or volume of ice melted in a day in the past.

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lazyjones
2009:
[https://www.youtube.com/watch?v=3F9FbdqGRsg](https://www.youtube.com/watch?v=3F9FbdqGRsg)

"at this rate of melting, Greenland is losing enough water each year to cover
Germany a meter deep"

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pas
[https://arctic.noaa.gov/Portals/7/easygalleryimages/8/367/te...](https://arctic.noaa.gov/Portals/7/easygalleryimages/8/367/tedesco-
fig3.png)

[https://upload.wikimedia.org/wikipedia/commons/9/92/NASA-
Sat...](https://upload.wikimedia.org/wikipedia/commons/9/92/NASA-Satellite-
sea-level-rise-observations-1993-Nov-2018.jpg)

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qserasera
There goes a lot of relatively fresh water into the sea

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phkahler
This is expected. That's why they built a bridge there.

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pas
Yes. The problem is the trend, not the intra-year variance.

[https://upload.wikimedia.org/wikipedia/commons/9/92/NASA-
Sat...](https://upload.wikimedia.org/wikipedia/commons/9/92/NASA-Satellite-
sea-level-rise-observations-1993-Nov-2018.jpg)

[https://arctic.noaa.gov/Portals/7/easygalleryimages/8/367/te...](https://arctic.noaa.gov/Portals/7/easygalleryimages/8/367/tedesco-
fig3.png)

