NAMIBE: Ice is heavy, so it’s only logical that when it disappears, the material below it rises. But it’s still tough to wrap your brain around the findings of three scientists who have shown that as Iceland’s ice caps are melting, the land is rising — and fast.
This month, a study authored by a team from University of Arizona and University of Iceland shows exactly how dramatic the unexpected effects of climate change really are. The paper, Climate driven vertical acceleration of Icelandic crust measured by CGPS geodesy, analysed data from GPS sensors all over Iceland to measure how much and how often those points of land moved (geodesy is the science of measuring the Earth’s surface). The authors kept track of just how far the sensors shifted over time — and found that those data points told a fascinating and awful story.
Of the 62 sensors, 27 of them located in the centre of Iceland where the most ice cover is located showed upward velocity, some as much as 1.4 inches (3.56cm) a year. “Sites in central and southern Iceland, closest to the major ice caps, which measure the largest velocities and accelerations, also display the largest annual variations in vertical position,” the authors explain in the paper, which will be published in Geophysical Research Letters but is available as a preview through a small paywall online.
It’s a phenomenon called “uplift”, and this isn’t the first time it’s been observed; after all, glaciers are disappearing all over the world. In 2009, The New York Times reported that the uplift in Alaska has been so fast, the sea level is dropping — an almost comically inverted version of how we normally think about climate change. In an online release about the study, University of Arizona’s Mari N. Jensen explains further.
