The Ross Ice Shelf- the worlds largest ice cubeThis is a ‘series’ post. Part 1. In the coming weeks

The Ross Ice Shelf- the worlds largest ice cubeThis is a ‘series’ post. Part 1. In the coming weeks I will be delivering a series of posts about the importance of the Ross Ice Shelf, Antarctica. This first post presents a brief introduction to Antarctica and the Ross Ice Shelf.Antarctica is the highest, driest, coldest and windiest continent on earth. Antarctica is the least populated of all of the continents with approximately 4000 inhabitants in the summer months across the ~75 research stations. It is a huge continent, with an area over 50% greater than the United States of America, or, 1.82 times the size of Australia! Less than 1% of the Antarctic continent is ice free, with the rest covered by glacial ice, nearing 4000m thick in certain places. The Antarctic plateau, with average heights of nearly 3000m above sea level, averages a year round temperature of -50°C, and is also home to the lowest recorded temperature in nature of -89.2°C at Russia’s Vostok Station.The Ross Ice Shelf is a large mass of floating ice, attached to the grounded Antarctic ice sheet. It is situated between 160°E and 150°W longitude and 78°S and 85°S latitude, bounded by the Transantarctic Mountains to the south and west, by Marie Byrd Land to the east and by the Ross Sea to the north. The shelf is approximately 520,000km2 in size. To put that in perspective, that’s larger than Spain!While the Ross Ice Shelf may be considered a permanent, static ice shelf on a human timescale, it is far from that, with geological studies identifying the dynamic nature of this ice shelf. As part of the ANDRILL drilling project on the Ross Ice Shelf (watch: https://www.youtube.com/watch?v=YxW5Cp8X9vg), it was found that the Ross Ice Shelf completely disintegrated approximately four million years ago. At this point in time, the concentration of CO2 was approximately 400ppm in the atmosphere, the earth was approximately 3°C warmer and the majority of the West Antarctic Ice Sheet (WAIS) had melted, which resulted in a global sea level rise of approximately 7m. On the 10th of May 2013, global CO2 levels reached 400ppm at Mauna Loa for the first time since measurements began in 1958. The earth’s atmosphere is therefore back to the same CO2 levels that caused the last collapse of the ice shelf and past studies have estimated it could collapse again, possibly in as little as 1000 years.“Although that 1000 year timeline might make it seem like we’ve got plenty of time to change our path, a different study is much more ominous. In this model, from scientists at Pennsylvania State University and the University of Massachusetts, two factors were included that weren’t in previous models. They included hydrofracturing (which is surface meltwater percolating down cracks in the ice and expanding as it refreezes, exacerbating the existing cracks and crevasses) and the fact that vertical ice cliffs can fail suddenly; a property not included in simple ice-flow models.By incorporating these two new factors into the model, the expected collapse of the West Antarctic Ice Sheet was estimated to occur within decades. The model depicts a collapse of the Ross Ice Shelf within 50 years (full article: http://www.sciencedirect.com/science/article/pii/S0012821X14007961). The Ross Ice Shelf itself won’t contribute to sea level rise if it melts, as it is already floating, but its importance will be outlined in the following posts.-MJAImage Credit: Marcus Arnoldfurther reading: http://www.andrill.org/static/index.html -- source link

More pics about