Quote of the Day
It is better to fail in originality than to succeed in imitation.
I just read an article about a large iceberg that will likely form in 2017 when a 5,000 km2 section of the Larsen C ice shelf (Figure 1) calves into the Antarctic Ocean. There is concern that the formation of this iceberg will remove a barrier that has been preventing the entire Larsen C ice shelf, with a total area of over 50,000 km2, from sliding into the sea. This is a massive amount of ice.
According to this article, if the land-based portion of the Larsen C ice shelf slides into the sea, sea level would rise by 10 cm. Let's try to approximate this calculation. Figure 2 shows a map of the ice thickness.
It looks like most of the ice sheet is about 650 m to 750 m thick. I will assume the average ice thickness is 700 m, which we can use to estimate the sea level rise as shown in Figure 3. I get 9 cm of sea level rise, which is close enough for a rough estimate like this.
Figure 3 shows a giant rift forming along the edge of the Larsen C ice sheet, which is expected to calve off this year. The iceberg formed is expected to be one of the ten largest ever recorded.
The radius of the Earth is actually 6370 km, so your calculation is a little pessimistic. Nevertheless, the consequences of global warming for us all is well illustrated. I'm writing this from a boat sailing off the coast of Norway inside the Arctic circle. The temperature is a balmy 6 degrees centigrade and the only visible snow is on the mountain peaks.
Thanks Malcolm. I meant to write 4000 miles, not 4000 km. This means that the sea level rise is ~ 4 cm instead of 10 cm. I wonder if the original author made the same error?
mark
P.S. I find my error. I was assuming the land-based portion was the same thickness as the sea-based portion of the ice sheet. The difference is quite large. I have updated the post. Again, thanks for pointing out the issue.