Antarctica Had Vast Regions Melt Recently
Written by Fraser Cain
Much of the concern for global warming has been focused on the Arctic Ocean, where sea ice is disappearing faster than scientists had predicted. The southern regions of the Earth didn't seem to be as affected. But new satellite images from NASA's QuikScat satellite are showing that Antarctica is melting too.
QuikScat measured snowfall accumulation and melting in Antarctica, tracking the period from July 1999 through July 2005. Scientists analyzing the results found that several distinct regions across the continent were accelerating their rate of snow melt. And these regions were places nobody would have anticipated. There was evidence of melting 900 km (560 miles) inland from the open ocean, only 500 km (310 miles) from the South Pole, and 2,000 metres (6,600 feet) above sea level.
These melting regions don't actually reach the sea; however, they refreeze into an extensive ice layer. The water can penetrate into ice sheets through cracks and glacial shafts, and then lubricate the underside of the ice sheet at the bedrock, causing the ice mass to move more quickly towards the ocean, and raising sea levels.
Original Source: NASA/JPL News Release
Filed under: Earth Observation
February 16th, 2008 at 8:36 pm
Mathematical modeling for destabilizing Antarctica’s ice sheet due to earth shrinking: the effect of heat and mass transfer on non-linear MHD boundary layer flow over a porous shrinking sheet
R. K. Samy, Muhaimin and Azme B Khamis
Centre for Science Studies,
Universiti Tun Hussein Onn Malaysia,
86400, Parit Raja, Batu Pahat Johor, Malaysia,
Email: future990@gmail.com
The rising atmospheric concentrations of carbon dioxide that are destabilizing the earth’s climate are driven by the burning of fossil fuels. Due to the effect of shrinking of earth, it is observed that the Antarctica's ice sheet is melting at a rate that increased dramatically from 1996 to 2006 [27]. It is hoped that the present investigation may be useful for the study of movement of Antarctica's ice sheet and shrinking of earth. Simulation analysis is presented to investigate the effect of heat and mass transfer on nonlinear MHD boundary layer past a shrinking sheet in the presence of suction. The cases of two dimensional and axisymmetric shrinking have been discussed. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are solved numerically by using the advanced numeric technique. Favorable comparison with previously published work is performed. Numerical results for the dimensionless velocity, temperature and concentration profiles as well as for the skin friction, heat and mass transfer are obtained and displayed graphically for pertinent parameters to show interesting aspects of the solution. It is predicted from the present investigation that the shrinking of earth due to the decrease of the earth’s porosity has been its potential to affect the stability of the Antarctic ice sheet and infrastructure of the earth.
CONCLUSIONS
In this work the problem of the effect of porous shrinking sheet due to heat and mass transfer on non-linear MHD boundary layer flow in the presence of suction is investigated. Due to the uniform shrinking of sheet, it is observed from the Table 1 and the Figs.5 and 6 that the rate of heat transfer of the fluid increases tremendously with decrease of porosity parameter and Prandtl number and also the effect of strength of magnetic effect is expected to alter the momentum boundary layer significantly. So, the shrinking and porosity of the sheet with magnetic effect have a substantial effect on the flow field and, thus, on the heat and mass transfer rate from the sheet to the fluid. Particularly, it is noticed that the rate of heat and mass transfer of the fluid increase with decrease of porosity of shrinking surface.
It is expected that this research may prove to be useful for the study of shrinking of earth. It is concluded from the present investigation that the shrinking of earth due to the decrease of the earth’s porosity has been its potential to affect the stability of the Antarctic ice sheet and infrastructure of the earth. The southern continent contains enough ice to raise ocean levels, a deluge that would put every major coastal city in the world deep under water and uproot hundreds of millions of people. On the other hand; it is observed that the earthquake and tsunami arise with reduces of porosity of the earth due to the increase of carbon rate in air. The rising atmospheric concentrations of carbon dioxide that are destabilizing the earth’s porosity and warming climate are driven by the burning of fossil fuels. Our choice is a simple one: reverse these trends or risk being overwhelmed by them. It is hoped that the results obtained will not only provide useful information for applications, but also serve as a complement to the previous studies.