Roaring glacial melt under the bridge to Kangerlussiauq, Greenland

https://twitter.com/Laurie_Garrett/status/1157015875276464129

by DoreenMichele • 7 years ago

89 12 7 years ago

cbkeller2• 7 years ago

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

adrianN• 7 years ago

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.

cbkeller2• 7 years ago

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

whycombagator2• 7 years ago

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.

scarygliders• 7 years ago

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

whycombagator2• 7 years ago

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.

neffy• 7 years ago

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.

qserasera• 7 years ago