It is well known that global warming is causing sea levels to rise via two processes: thermal expansion, when water expands because of its increased temperature, and melting of land-based ice, when meltwater flows into the ocean.
It is well known that global warming is causing sea levels to rise via two processes: thermal expansion, when water expands because of its increased temperature, and melting of land-based ice, when meltwater flows into the ocean. Less known, regarding the latter, is the nuanced phenomenon of gravitational pull. When a large ice sheet begins to melt, global-mean sea level rises, but local sea level near the ice sheet may in fact drop.
In American Journal of Physics, by AIP Publishing, a researcher from Saint Joseph’s University illustrates this effect through a series of calculations, beginning with a simple, analytically tractable model and progressing through more sophisticated mathematical estimations of ice distributions and gravitation of displaced seawater mass. The paper includes numerical results for sea level change resulting from a 1,000-gigatonne loss of ice, with parameter values appropriate to the Greenland and Antarctic ice sheets.
“If the meltwater comes from Greenland, then sea level far from Greenland rises by more than average, but sea level at the Greenland shore actually drops,” said author Douglas Kurtze. “This is at least partially because of how the loss of that ice changes the gravitational pull of the ice sheet.”
Read more at American Institute of Physics
Photo Credit: Simon via Pixabay
