Citat:
Jo, det finns viss avsmältning även om temperaturerna rör sig mot rekordlåga nivåer som under den Antarktiska vintern 2018 (Sommaren 2018 här):Du borde testa att läsa det som skrivs i tråden. Någon enstaka gång...
Fyrdubbling av smälttakten på knappt 20 år
Artikeln visar på en trend när det gäller smältande landis som är tydlig:
1979–1990: 40 ± 9 Gt/y
1989–2000: 50 ± 14 Gt/y
1999–2009: 166 ± 18 Gt/y
2009–2017: 252 ± 26 Gt/y
https://www.pnas.org/content/early/2019/01/08/1812883116
Om att läsa med ideologiskt filter...
Om man läser och inte förstår kan det ju ha olika orsaker. Trump lär inte kunna läsa utan Addreall/Dexamfetamin.
Om du har någon seriös och trovärdig källa som tyder på ett helt annat resultat än det som PNAS-artikeln visar om hur landisen smälter, så kan du väl länka?
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Fyrdubbling av smälttakten på knappt 20 år
Artikeln visar på en trend när det gäller smältande landis som är tydlig:
1979–1990: 40 ± 9 Gt/y
1989–2000: 50 ± 14 Gt/y
1999–2009: 166 ± 18 Gt/y
2009–2017: 252 ± 26 Gt/y
https://www.pnas.org/content/early/2019/01/08/1812883116
Om att läsa med ideologiskt filter...
Om man läser och inte förstår kan det ju ha olika orsaker. Trump lär inte kunna läsa utan Addreall/Dexamfetamin.
Om du har någon seriös och trovärdig källa som tyder på ett helt annat resultat än det som PNAS-artikeln visar om hur landisen smälter, så kan du väl länka?
–
Scientists record new lowest temperature on Earth in Antarctica
Temperatures at tiny valleys near the top of Antarctica's ice sheet could fall to nearly minus 100 degrees Celsius, beating all previous coldest records on Earth's surface, according to a new study.http://www.xinhuanet.com/english/2018-06/27/c_137283955.htm
Researchers found small dips or shallow hollows on the East Antarctic Plateau could be as cold as minus 98 degrees Celsius, refreshing the previous record of minus 93 degrees Celsius measured in 2013 in the same region.
The high elevation of the East Antarctic Plateau and its proximity to the South Pole give it the coldest climate of any region on Earth, while the small dips in the Antarctic Ice Sheet is the coldest of the coldest.
Antarktis landmassa är ju geoaktiv och geotermisk värme bidrar till avsmältningen:
Evidence of an active volcanic heat source beneath the Pine Island Glacier
Abstracthttps://www.nature.com/articles/s41467-018-04421-3#Sec2
Tectonic landforms reveal that the West Antarctic Ice Sheet (WAIS) lies atop a major volcanic rift system. However, identifying subglacial volcanism is challenging. Here we show geochemical evidence of a volcanic heat source upstream of the fast-melting Pine Island Ice Shelf, documented by seawater helium isotope ratios at the front of the Ice Shelf cavity. The localization of mantle helium to glacial meltwater reveals that volcanic heat induces melt beneath the grounded glacier and feeds the subglacial hydrological network crossing the grounding line. The observed transport of mantle helium out of the Ice Shelf cavity indicates that volcanic heat is supplied to the grounded glacier at a rate of ~ 2500 ± 1700 MW, which is ca. half as large as the active Grimsvötn volcano on Iceland. Our finding of a substantial volcanic heat source beneath a major WAIS glacier highlights the need to understand subglacial volcanism, its hydrologic interaction with the marine margins, and its potential role in the future stability of the WAIS.
The Antarctic Ice Sheet’s mass balance is governed indirectly by melting from below, which determines the rate at which ice flows from the interior of the continent to the ocean. My thesis addresses three sources of heat which contribute to basal melting: oceanic heat flux, geothermal heat flux, and heat from subglacial volcanism. I measured oceanic heat flux and geothermal heat flux at a location in West Antarctica where the ice sheet transitions from grounded on the continent to floating over the ocean. Oceanic heat flux and thus ice-shelf basal melt rates were low at this site (0.7 W m-2 or 7 cm yr-1) as a result of slow currents and stable stratification of colder and fresher water near the ice base. On the other hand, geothermal heat flux was moderately high at this site (0.09 W m2), though lower than the oceanic heat flux. Another measurement of geothermal heat flux only 100 km away revealed a much higher value (0.3 W m-2); this spatial variability in geothermal heat flux could be explained by magmatic intrusions and/or advection of heat by flowing crustal fluids.https://cloudfront.escholarship.org/dist/prd/content/qt91p7t2mm/qt91p7t2mm.pdf