Ruth MottramFeb 9, 2024

Well.
This is very interesting.

Essential reading for all who are interested in #IceSheet and #glacier dynamics..

https://fediscience.org/@iceadvice/111901479232959232
@iceadvice - North-East Greenland Ice Stream: It is most likely much younger than previously assumed - analysis of folds in the #NEGIS shear margin from @awi airborne radar data by Daniela Jansen et al in @Nature Comms.
https://www.nature.com/articles/s41467-024-45021-8
How old is it? Check the paper.

Olaf Eisen (@[email protected])

Attached: 1 image North-East Greenland Ice Stream: It is most likely much younger than previously assumed - analysis of folds in the #NEGIS shear margin from @[email protected] airborne radar data by Daniela Jansen et al in @[email protected] Comms. https://www.nature.com/articles/s41467-024-45021-8 How old is it? Check the paper.

FediScience.org
Olaf EisenFeb 9, 2024
North-East Greenland Ice Stream: It is most likely much younger than previously assumed - analysis of folds in the #NEGIS shear margin from @awi airborne radar data by Daniela Jansen et al in @Nature Comms.
https://www.nature.com/articles/s41467-024-45021-8
How old is it? Check the paper.
Shear margins in upper half of Northeast Greenland Ice Stream were established two millennia ago - Nature Communications

The flow of ice streams leaves traces in the stratigraphy of the ice sheets. Made visible by radar, they reveal the history of the upper North East Greenland Ice Stream. The ice stream is found to have existed in its current form for only about the last 2000 years.

Nature
Kerim Hestnes NisanciogluNov 1, 2023

Tamara Gerber: Ice in the Northeast Greenland Ice Stream is 50x harder in the centre of flow, resisting along-flow extension/compression. While the shear margins are relatively soft. #EASTGRIP #NEGIS

https://www.nature.com/articles/s41467-023-38139-8

Crystal orientation fabric anisotropy causes directional hardening of the Northeast Greenland Ice Stream - Nature Communications

This study uses radio-echo sounding measurements, ice-core data and models to map the spatial variation in ice-crystal orientation in the northeast Greenland Ice Stream and shows how it potentially affects the ice-flow dynamics in this region.

Nature
Kerim Hestnes NisanciogluNov 1, 2023

Exiting new results from #eastgrip by @agrinsted and Christine Hvidberg showing widening shear margins and accelerating ice high up on the Northeast Greenland Ice Stream #NEGIS

https://www.glaciology.net/publication/2022-09-23-negis-acceleration/

Accelerating ice flow at the onset of the Northeast Greenland Ice Stream

Deep in the interior of the Greenland ice sheet, ice flow is speeding up — but not due to recent changes in climate.

Olaf EisenJul 24, 2023
#EGRIP #EastGRIP drilled through the North-East Greenland Ice Stream #NEGIS yesterday. Great moment!
Details from @egripcamp https://twitter.com/egripcamp/status/1683366672374149121?s=21
EastGRIP Camp on Twitter

“Our drillers, Steff and Trevor, with the bedrock mud core (gray scale, taken in red light)”

Twitter
Olaf EisenMay 9, 2023

#icesheet #modellers, we have a challenge for you: if you want to get #NEGIS dynamics right, you might want to include anisotropy. Strong influence on viscosity.

Our fabric observations from #radioglaciology and #icecores for the #NEGIS onset around @egripcamp are out
https://www.nature.com/articles/s41467-023-38139-8
Gerber et al. @TamaraGerber5 @naturecomms

Crystal orientation fabric anisotropy causes directional hardening of the Northeast Greenland Ice Stream - Nature Communications

This study uses radio-echo sounding measurements, ice-core data and models to map the spatial variation in ice-crystal orientation in the northeast Greenland Ice Stream and shows how it potentially affects the ice-flow dynamics in this region.

Nature
💧🌏 Greg CocksDec 28, 2022
Sea Levels Might Rise Much Faster Than Thought, Greenland Data Suggest
--
https://www.space.com/greenland-ice-melting-satellite-data-climate-change <-- article
--
https://doi.org/10.1038/s41586-022-05301-z <-- shared paper
--
#GIS #spatial #mapping #model #modeling #spatialanalysis #remotesensing #future #interior #marine #water #hydrology #Greenland #melting #ice #snow #climatechange #icesheet #climate #GrIS #NEGIS #speed #thinning #sealevelrise #SLR #hydrospatial #elevation #massbalance #GNSS
Sea levels might rise much faster than thought, data from Greenland suggest

"If this is correct, the contribution of ice dynamics to overall mass loss on Greenland will be larger than what current models suggest."

Space
Show threadOlaf EisenDec 5, 2022

Ice stream in Greenland can be short-lived! New exciting results from @__sfranke__ using data from the @AWI_media airborne radar obtained at the @egripcamp on the North-East Greenland Ice Stream #NEGIS with #Radioglaciology

https://www.nature.com/articles/s41561-022-01082-2

https://www.awi.de/en/about-us/service/press/single-view/kurzlebige-eisstroeme.html

Holocene ice-stream shutdown and drainage basin reconfiguration in northeast Greenland - Nature Geoscience

Two ice streams—indicated by buried folds—extending into the interior of the northeastern Greenland ice sheet deactivated in the Holocene as the drainage basin flow regime reorganized southwards, according to an analysis of radio-echo sounding data.

Nature
Ruth MottramNov 10, 2022

Just been interviewed about this new paper Khan et al from our colleagues at #DTUSpace - it's about the NE #Greenland #IceStream #NEGIS that drains a large areas of the #IceSheet + that has accelerated and thinned since at least the early 2000s

https://www.nature.com/articles/s41586-022-05301-z

Extensive inland thinning and speed-up of Northeast Greenland Ice Stream - Nature

Analysis of global navigation satellite system observations and satellite data shows that frontal changes in 2012 of the North-East Greenland Ice Stream led to speed-up and thinning at least 200 km inland.

Nature
Aslak GrinstedNov 9, 2022

The large North East Greenland Ice Stream is speeding up. It is accelerating at the front, it is accelerating in the back, and also in between. Changes to #NEGIS is important for #SeaLevelRise because it is a large part of the #Greenland mass budget.

Two new papers
* Khan and friends on how frontal changes are spreading in land: https://www.nature.com/articles/s41586-022-05301-z
* Me and friends on what is happening even further back: https://www.nature.com/articles/s41467-022-32999-2

Extensive inland thinning and speed-up of Northeast Greenland Ice Stream - Nature

Analysis of global navigation satellite system observations and satellite data shows that frontal changes in 2012 of the North-East Greenland Ice Stream led to speed-up and thinning at least 200 km inland.

Nature