Journal Entry

Cryosphere: From the Greek κρύος cryos - cold, frost, or ice and σφαῖρα sphaira - globe, ball

Cryosphere is the term which collectively describes the portions of the Earth’s surface where water is in solid form, including sea ice, lake ice, river ice, snow cover, glaciers, ice caps and ice sheets, and frozen ground (which includes permafrost).

At noon on July 4, Sebastian Mernild, from the University of Copenhagen, an expert on anything related to the cryosphere, presented a lecture via Skype to the JSEP team titled, “The Melting Glacial Ice in the Arctic.”

Lecture by Sebastian MernildSebastian Mernild, cryosphere expert, gave a lecture via Skype on Melting Glacier Ice in the Arctic.

There are many ways a glacier can melt: ablation, calving, running rivers, and discharge. The production of iceberg calving has become one of the most dramatic and profound effects to glacial loss.

When huge parts of the ice sheet break off from the shelf the land rises (due to the immense weight being removed), this causes the mantle to fluctuate and is the source to seismic waves, and consequently glacial earthquakes which become increasingly common with rising global temperatures.

Mernild tended to concentrate his lecture on the idea of the darkening of the ice sheet, this warming is a self-enforcing process: darker ice reflects less sunlight which accelerates warming and melting. Since 1931, the glacial terminus has retreated 1,300 meters and averages a retreat of sixteen meters a year.

Mernild then shifted his focus from dark ice to exposed ice. Snow loss from the margins expose ice containing soot, dust and other particles, this impacts runoff and in the larger picture might even change oceanic circulation and currents. This could occur because the salinity of the fresh water from the Greenlandic ice sheet impacts the density of the sea water.

Although it’s a hypothesis that the melting of the Greenlandic ice sheet will affect ocean currents and circulation, the melt has already contributed to the global sea level rising. He concluded by saying that out of all the ice in the world, Greenland would contribute twenty percent to the global sea level.