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Ursprungligen postat av
Brain Damage
Men isen smälte inte i videon, den bröts loss, kalvade. När isen väl kalvar kan det ske i större eller mindre omfattning. Det har skett i eoner och är inget nytt fenomen bara för att det nu för tiden oftare fångas på bild.
Nej, det framgår tydligt av videon att det inte handlar om en expanderande glaciär utan en tillbakadragande glaciär, d.v.s kalvningen beror i stor grad av ytvattenssmältning.
Saxat från wikipedia:
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Jakobshavn is one of the fastest moving glaciers, flowing at its terminus at speeds of around 20 metres per day.[11] The speed of Jakobshavn Glacier varied between 5700 and 12600 metres per year between 1992 and 2003.[1] The ice stream's speed-up and near-doubling of ice flow from land into the ocean has increased the rate of sea level rise by about 0.06 millimeters (about 0.002 inches) per year, or roughly 4 percent of the 20th century rate of sea level rise.[12] Jakobshavn Isbrae, retreated 30 km from 1850–1964, followed by a stationary front for 35 years. Jakobshavn has the highest mass flux of any glacier draining the Greenland Ice Sheet. The glacier terminus region also had a consistent velocity of 20 meters/day (maximum of 26 m/day in glacier center), from season to season and year to year, the glacier seemed to be in balance from 1955-1985.[13] After 1997 the glacier began to accelerate and thin rapidly, reaching an average velocity of 34 m/day in the terminus region. It also thinned at a rate of up to 15 m/year and retreated 5 km in six years. Jakobshavn has since slowed to near its pre-1997 speed, the terminus retreat is still occurring
Genom att enbart läsa sista raden tolkar vissa individer det som att allt är lugna gatan trots att glaciären fortfarande drar sig tillbaka.