Roaring glacial melt under the bridge to Kangerlussiauq, Greenland | Hacker News Reader

Roaring glacial melt under the bridge to Kangerlussiauq, Greenland

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89 pointsDoreenMichele46 comments

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

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.

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

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

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.

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

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.

Can confirm. I was there 3 years ago, this time of the year, and this is way higher than it was during the week I was there.

2009: 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"

https://arctic.noaa.gov/Portals/7/easygalleryimages/8/367/te...

https://upload.wikimedia.org/wikipedia/commons/9/92/NASA-Sat...

There goes a lot of relatively fresh water into the sea

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

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

https://upload.wikimedia.org/wikipedia/commons/9/92/NASA-Sat...

https://arctic.noaa.gov/Portals/7/easygalleryimages/8/367/te...

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