Talk:Thwaites Glacier

Untitled reference

 * Heterogeneous retreat and ice melt of Thwaites Glacier, West Antarctica. Science Advances 30 Jan 2019  — Preceding unsigned comment added by Conan (talk • contribs) 21:58, 2 February 2019 (UTC)

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RESEARCHERS FIND MAJOR WEST ANTARCTIC GLACIER MELTING FROM GEOTHERMAL SOURCES "Thwaites Glacier, the large, rapidly changing outlet of the West Antarctic Ice Sheet, is not only being eroded by the ocean, it’s being melted from below by geothermal heat, researchers at the Institute for Geophysics at The University of Texas at Austin (UTIG) report in the current edition of the Proceedings of the National Academy of Sciences.

The findings significantly change the understanding of conditions beneath the West Antarctic Ice Sheet where accurate information has previously been unobtainable.

The Thwaites Glacier has been the focus of considerable attention in recent weeks as other groups of researchers found the glacier is on the way to collapse, but more data and computer modeling are needed to determine when the collapse will begin in earnest and at what rate the sea level will increase as it proceeds. The new observations by UTIG will greatly inform these ice sheet modeling efforts." https://www.eurekalert.org/pub_releases/2014-06/uota-rfm060514.php https://phys.org/news/2014-06-major-west-antarctic-glacier-geothermal.html

Variable crustal thickness beneath Thwaites Glacier revealed from airborne gravimetry, possible implications for geothermal heat flux in West Antarctica (2014) "Thwaites Glacier has one of the largest glacial catchments in West Antarctica. The future stability of Thwaites Glacier's catchment is of great concern, as this part of the West Antarctic Ice Sheet has recently been hypothesized to already be en route towards collapse. Although an oceanic trigger is thought to be responsible for current change at the grounding line of Thwaites Glacier, in order to determine the effects of this coastal change further in the interior of the West Antarctic Ice Sheet it is essential to also better constrain basal conditions that control the dynamics of fast glacial flow within the catchment itself. One major contributor to fast glacial flow is the presence of subglacial water, the production of which is a result of both glaciological shear heating and geothermal heat flux. The primary goal of our study is to investigate the crustal thickness beneath Thwaites Glacier, which is an important contributor to regional-scale geothermal heat flux patterns. Crustal structure is an indicator of past tectonic events and hence provides a geophysical proxy for the thermal status of the crust and mantle. Terrain-corrected Bouguer gravity disturbances are used here to estimate depths to the Moho and mid-crustal boundary. The thin continental crust we reveal beneath Thwaites Glacier supports the hypothesis that the West Antarctic Rift System underlies the region and is expressed topographically as the Byrd Subglacial Basin. This rifted crust is of similar thickness to that calculated from airborne gravity data beneath neighboring Pine Island Glacier, and is more extended than crust in the adjacent Siple Coast sector of the Ross Sea Embayment. A zone of thinner crust is also identified near the area's subaerial volcanoes lending support to a recent interpretation predicting that this part of Marie Byrd Land is a major volcanic dome, likely within the West Antarctic Rift System itself. Near-zero Bouguer gravity disturbances for the subglacial highlands and subaerial volcanoes indicate the absence of supporting crustal roots, suggesting either (1) thermal support from a warm lithosphere or alternatively, and arguably less likely; (2) flexural support of the topography by a cool and rigid lithosphere, or (3) Pratt-like compensation. Although forward modeling of gravity data is non-unique in respect to these alternative possibilities, we prefer the hypothesis that Marie Byrd Land volcanoes are thermally-supported by warmer upper mantle. The presence of such inferred warm upper mantle also suggests regionally elevated geothermal heat flux in this sector of the West Antarctic Rift System and consequently the potential for enhanced meltwater production beneath parts of Thwaites Glacier itself. Our new crustal thickness estimates and geothermal heat flux inferences in the Thwaites Glacier region are significant both for studies of the structure of the broader West Antarctic Rift System and for assessments of geological influences on West Antarctic Ice Sheet dynamics and glacial isostatic adjustment models." http://www.sciencedirect.com/science/article/pii/S0012821X14005780

Evidence for elevated and spatially variable geothermal flux beneath the West Antarctic Ice Sheet (2014) "Thwaites Glacier is one of the West Antarctica's most prominent, rapidly evolving, and potentially unstable contributors to global sea level rise. Uncertainty in the amount and spatial pattern of geothermal flux and melting beneath this glacier is a major limitation in predicting its future behavior and sea level contribution. In this paper, a combination of radar sounding and subglacial water routing is used to show that large areas at the base of Thwaites Glacier are actively melting in response to geothermal flux consistent with rift-associated magma migration and volcanism. This supports the hypothesis that heterogeneous geothermal flux and local magmatic processes could be critical factors in determining the future behavior of the West Antarctic Ice Sheet." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4078843/

The actual paper DOES mention the geothermal heat flux under the glacier, so the reporters have no excuse for not mentioning it... https://www.the-cryosphere.net/12/3861/2018/tc-12-3861-2018.pdf

Sea level rise
" This study has raised alarm regarding the glacier collapse, which can lead to nearly 3 ft rise in the sea level. " Can someone clarify what the glacier's contribution to sea level rise is likely to be? Another source says "more than half a meter", which may or may not be the same as "nearly 3 ft". Also the paragraph has a confusing mix of imperial and metric units (celsius and feet), and the sentence quoted (and much of the paragraph) seems to be lifted directly from the Time of India article cited. — Preceding unsigned comment added by 167.57.196.246 (talk) 20:20, 8 February 2020 (UTC)

Infobox needs basic date added
Infobox needs basic date: area; length; width; max & min elevation, etc.  — Lentower (talk) 17:59, 25 August 2021 (UTC)


 * Belatedly, I added area and width. However, max elevation does not appear to be listed in any RS I could find, only ice thickness. Neither is length: I suppose it can be worked out from area and width, but this is probably not an exercise we should be engaging in. InformationToKnowledge (talk) 15:42, 13 July 2023 (UTC)

Update
https://www.livescience.com/agu-antarctica-thwaites-glacier-future 199.127.133.181 (talk) 17:38, 14 December 2021 (UTC)

Map please!
Can someone find/create a map for this? Thanks! -TenorTwelve (talk) 21:28, 16 December 2021 (UTC)
 * The EOS article in the para below has such a map. But I couldn't get it to work! -- except as the tiny thumbnail. --Pete Tillman (talk) 23:13, 17 March 2023 (UTC)
 * I added nine more images recently, including some more maps. The one which currently illustrates the "Importance" section is probably the closest to what you have been looking for. InformationToKnowledge (talk) 15:44, 13 July 2023 (UTC)

Robot submersible investigates the bottom of Thwaites glacier
https://eos.org/articles/icefin-investigates-a-glacial-underbelly “Icefin” Investigates a Glacial Underbelly -- An instrument-laden submersible reveals where—and how rapidly—the Antarctic glacier is melting." EOS News, 15 March 2023. Interesting  article, sort of a good-news, bad news combo. The good news is that "the underside of Thwaites is melting far less rapidly than predicted by models." So "the glacier’s lower melt rate [may] translate into slower retreat in the future." Time will tell. Pete Tillman (talk) 23:11, 17 March 2023 (UTC)


 * Added to the article now, along with the original studies and an additional supporting reference. InformationToKnowledge (talk) 15:45, 13 July 2023 (UTC)

Removed mention of people's names and their affiliations
I hope this is not controversial but I have just condensed some of the sentences by removing a mention of the names of scientists (especially those who are not notable in the Wikipedia logic, i.e. no Wikipedia articles) and their affiliations or the journal papers where they published in. I think all this is maybe relevant for an academic literature review but not for an encyclopedic article. Readers can find author names and universities if they click on the reference at the end of the sentence or paragraph. I think we should focus on the science and the observations, which less emphasis in the prose on where the scientists worked at the time, which journal they published in, or where the interview was published etc. I haven't removed it in all sentence but felt that those details were provided too often. EMsmile (talk) 22:35, 23 July 2023 (UTC)

Adversely affected?
The lead claims faster melting is "adverse"? Based on what? Is Spring (in the Northern Hemisphere) an "adverse event"??? Whether it is beneficial or detrimental depends on the answer to the question:"to What?" and is completely subjective - and clearly not neutral. (I note that water is expected to become an increasingly scarce resource in the decades ahead, so the net effects of higher sea level and lower salinity are moot, imho.)98.21.208.178 (talk) 10:19, 6 March 2024 (UTC)


 * There is no credible opinion that sea level rise provides any kind of a solution to fresh water scarcity. Quite the opposite in fact. See Effects of climate change on agriculture. The other reasons why sea level rise is universally agreed to be an adverse event (a process, really) are listed in that very article. InformationToKnowledge (talk) 12:30, 7 March 2024 (UTC)

Papers
We present evidence for seawater intrusions occurring at tidal frequencies over many kilometers beneath the grounded ice of Thwaites Glacier, West Antarctica, a major contributor to sea level rise. The results call into question the traditional approach of modeling a fixed, abrupt transition from grounded ice to ice floating in the ocean with no ice melt at the transition boundary. We delineate a tidally controlled grounding zone, 2 to 6 km in length, and additionally irregular seawater intrusions extending another 6 km inland at spring tide. The rushing of seawater beneath grounded ice over considerable distances makes the glacier more vulnerable to melting from a warmer ocean than anticipated, which in turn will increase projections of ice mass loss. https://www.pnas.org/doi/10.1073/pnas.2404766121 AaronNGray (talk) 02:55, 21 May 2024 (UTC)


 * Added. InformationToKnowledge (talk) 17:55, 25 May 2024 (UTC)

Replace the term "mélange"?
I am surprised to see the French word "mélange" mentioned twice in this article. Is this really necessary? Couldn't we just replace it with the English words "mixture" or "jumble"? Or is there a specific reason why "mélange" has to be used? One of the occurrences is in this sentence (which I find a bit too long as well): It shows the glacier, the ice shelf on its eastern side, and the remains of the ice tongue in the west, now reduced to a "mélange" of icebergs which is much less effective at supporting the glacier and preventing calving events.. EMsmile (talk) 07:44, 10 July 2024 (UTC)