A recent report from researchers has exposed the existence of billions of tons of liquid water found under Greenlands ice sheet. This new information helps to explain inconsistencies between perceived and estimated water run off and sea level rise, allowing a clearer picture of how the ice sheets accumulate and slough off melt water. Similar to Lake Vostok in Antarctica the liquid water is insulated against sub freezing temperatures by a thick layer of snow. The liquid layer is formed of billions of tons of semi-frozen water suspended in a slush between two solid layers of ice. The aquifer lies about 12 meters beneath the frozen surface of South East Greenlands tundra, and covers an area of about 70,000 square kilometers. Although this explains several issues researchers have had with run off and spring melt measurements, it raises several new questions about how water behaves at sub-zero temperatures when different pressure and insulation situations are present.
The liquid layer came as a surprise as it had only been observed once previously in the antarctic, and then under very different, much more extreme circumstances. When core sample drills came back to the surface dripping wet, the first reaction was panic over thousands of dollars of sensitive electronic equipment. But soon after that researchers realized the importance of the discovery of billions of tons of liquid water found under Greenlands ice sheet they returned with specialized probes that showed the aquifers temperature to be hovering right around zero degrees Celsius, much warmer than was expected in the frigid climate. This information alone changes what is known about the amount of melt water that reaches the sea because warmer water moves more quickly than colder water. The aquifer was discovered in South Eastern Greenland after years of research and projects had explorers distracted with other portions of the ice sheet. A project involving snow depth had a team drill down into the tundra, resulting in the discovery of the liquid layer of slush and water beneath the omnipresent ice layer.
The billions of tons of liquid water found under Greenlands ice sheet shine new light on the issue of global warming, as continuing research determines the aquifers volume to be about 154 billion tons, enough to raise the worlds ocean levels by 0.016 inches if it were to all reach the sea at the same time. The enormous reservoir is believed to be responsible for differences between projected sea level rise compared to arctic ice melts and actual observations, as melt water was expected to run along the surface of the many glaciers and tundras of Greenland instead of being stored under a layer of year round persistent ice and snow. With the realization that a substantial portion of melt is being held within the borders of Greenland, further projections can take into account the massive amount of water held in stasis to more accurately predict sea level rise in the coming years. This fine tuning of knowledge about the total volume of water affected by global freezing and melting will be used to fine tune future projections of sea level rise and fresh water availability for the entire world.
By Daniel O’Brien