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💧🌏 Greg CocksGregCocks@techhub.social
2025-03-18

New Map Of Landscape Beneath Antarctica Unveiled
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phys.org/news/2025-03-landscap <-- shared technical article
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doi.org/10.1038/s41597-025-046 <-- shared paper
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#GIS #spatial #mapping #Bedmap3 #icebed #surface #thickness #gridded #datasets #Antarctica #raster #model #modeling #landscape #elevation #icesheet #survey #remotesensing #earthobservation #climatechange #warming #climate #melt #melting #seafloor #subglacial #geophysical #survey #topography #geology #bathymetry #topobathy #BritishAntarcticSurvey
@BritishAntarcticSurvey

schematic / flow chart - Schematic showing the Bedmp3 source datasets (white boxes) combining to make intermediate products (blue boxes) and ultimately the final set of grids (orange boxes) and their uncertainties (yellow boxes). Note that the surface grid has a uniform estimated uncertainty (Section Uncertainty estimates).maps - Bedmap3 grids of (a) bed topography and (b) surface elevation, in metres above sea level (g104c geoid), and (c) ice thickness in metres. Locations labelled in (b) are referred to in the textThe BedMachine v3 bed has some subjective advantages over Bedmap3 where glacier flow is relatively fast, but survey data are sparse. (a) Surface flow speed43; (b) BedMachine v3 bed topography; (c) Bedmap3 bed topography, both overlaid on shaded relief and with survey data shown as grey lines. The black dotted line highlights a trough under slow-flowing ice that is more smoothly continuous in Bedmap3. The white oval highlights the trough of a relatively fast-flowing ice stream that in BedMachine v3 is more smoothly streamlined and subjectively more realistic than in Bedmap3, given the typical streamlined form of deglaciated ice stream landscapes. An objective test of bed accuracy in this area requires more survey data.maps - The Bedmap3 survey dataset allows us to calibrate the more continuous and extensive freeboard-based ice shelf thickness grid. (a) Pointwise ice thickness biases between 119,000 survey measurements and the freeboard-derived ice thickness grid47 on the Ross Ice Shelf, showing coherent patterns of bias; (b) these pointwise offsets median-filtered over a 20 km radius; (c) spline-interpolated calibration grid of the filtered offsets in (b); (d) bias-corrected version of the freeboard-derived ice thickness grid after subtraction of the calibration grid in (c).
John Vaccaro (johniac)johniac
2025-02-14

SciTech Chronicles. . . . . . . . .Feb 14th, 2025

bit.ly/stc021425

first-generation -of-life

Matt Willemsenmattotcha
2024-04-20

New geological map reveals secrets of Greenland's icy interior
phys.org/news/2024-04-geologic

Lukas VFN 🇪🇺animalculum@scholar.social
2024-02-20

Subglacial Microbial Life on Earth and Beyond asm.org/Articles/2024/February

"Jill Mikucki, Ph.D. studies one such analog site: Blood Falls in the McMurdo #DryValleys of #Antarctica. There, a briny, #subglacial #groundwater #ecosystem leaks iron-containing #brine to the surface... Mikucki has been working on subglacial environments for over 2 decades but is still stunned by some of her team's discoveries... the #microbial cells grow very slowly under the ice, possibly taking a year or more to divide."

Blood Falls, Antarctica, where microbes live under the ice. Iron and other elements from the bedrock below the ice become oxidized when it interacts with air, producing the rusty red coloring.
Snowshadow 🇨🇦Snowshadow
2023-12-05

Satellite map of North America's largest glacier shows 'hidden lagoon' and other secrets
"NASA has released a trippy, technicolor satellite photo of Alaska's Malaspina Glacier, which makes the massive ice mass look like a fiery, rippling blob of paint. The new image highlights recent discoveries at the glacier, including a "hidden lagoon"


space.com/largest-glacier-hidd

#

Dr. Brad Rosenheim has moved!Brad_Rosenheim@climatejustice.rocks
2023-04-21

It's niche, but I think it's cool. Today we published an article detailing successes and challenges of coring lake sediments when the lake is buried under a kilometer of ice.
#Antartica
#SALSA
#LakeMercer
#NSF
#USAP
#glacial
#subglacial
#sediments
#geology

onlinelibrary.wiley.com/share/

Dr. Brad Rosenheim has moved!Brad_Rosenheim@climatejustice.rocks
2023-03-11

‼️Publication claxon‼️

Led by former student in my lab @raventurelli@twitter.com and other collaborators (on that other site), we find layered lake #sediment! So, what? That's been done before, you say?

Well, this lake was under 1100 m of Antarctic ice and had never been accessed by humans before we cleanly (no #microbial contamination, and no easy feat!) accessed it! These sediments give us an idea of how long #Antarctic #subglacial #lakes exist.

beta.nsf.gov/news/first-ever-l

Dr. Brad Rosenheim has moved!Brad_Rosenheim@climatejustice.rocks
2023-02-15

Love #science? In central #Florida? The #SouthernOceanScience group is proud to present several exhibits at @twitter@stpetescifest 2023 - a community celebration of science. Join us Feb 18 at @twitter@USFSP (University of South Florida, Saint Petersburg) to explore activities to bring out the scientist in everyone.

I will be screening #TheLakeAtTheBottomOfTheWorld #documentary about our recent expedition to sample a #subglacial lake under 1100m if ice.

#ScienceInTheSun
antarcticlakefilm.com

Nafnlaus 🇮🇸 🇺🇦nafnlaus@fosstodon.org
2022-12-08

8. "What #mineral, produced by #subglacial #eruptions and spread via #aeolian distribution, is a problem for farmers in #Iceland, and why?"

#ChatGPT3 #GPT3 failed this (admittedly difficult) question (the answer is allophane, which binds phosphorus and other minerals, water, and reduces soil cohesion).

Dominic SaundersonPolarSaunderson@toot.io
2022-12-01

Great new paper by Dominic Hodgson and Tom Jordan from #BAS.

Using #Lidar, #Radar & #AirbornePhotography data, they identify the rapid drainage and slow refilling of a ~46m subglacial lake on the #AntarcticPeninsula.

Such findings have implications for the connectivity of the surface and #Subglacial hydrological networks, and, the authors hypothesise, the thermal regime of the #Ice.

Read the #OpenAccess paper here: doi.org/10.5194/tc-16-4797-202

#DomsDailyPolarPaper #Cryosphere #Antarcticles

Figure 2 from Hodgson, Jordan et al. (2022). This figure consists of 4 oblique aerial photographs showing the surface of the collapsed lake, taken in 2011 and 2018. Ice cliffs about 25m high are evident around the lake, which is approximately 250m in diameter. Also visible are surface meltwater streams, crevasses, and a drainage conduit, as well as Mount Phoebe, the Northern Phobos Ridge, and the Mars Glacier in the background of the images.Figure 8 of Hodgson, Jordan et al. (2022). A scatter plot of the elevation of the collapsed lake floor on the y-axis over time on the x-axis, from January 2013 until December 2019. The floor elevation has increased approximately linearly at a rate of 3.18m per year. Data is taken from REMA for the four points before 2017, and from LIDAR for the four observations in December 2019, when the rate increased.

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