Researchers from the University of Arizona, and the University of Iceland, reported that Iceland’s landscape is increasing by 1.4 inch each year as glaciers melt, and crust below and near rebounds. This means that less land is being pushed down by melting glaciers, which causes it to rise. The geoscientists warned that volcanic activity is likely to increase as it did during the last deglaciation roughly 12,000 years ago. The study was published in Geophysical Research Letter. Citation below. To determine the rate at which land is rising, geoscientists applied Iceland’s Geodesy Network of Sensitive GPS Receivers (red triangles). (Credit Kathleen Compton/UA Department of Geosciences. Photo: University of Arizona. The study by the team shows the rapid uplift of Icelandic crust due to the acceleration melting of Iceland’s glaciers. This coincides with current global warming which began about 30years ago. Researchers were shocked to discover that certain areas in central Iceland have been rising up to 1.4 inches per year. Kathleen Compton (a University of Arizona geosciences doctoral student) was the first author. She stated: “Our research links recent accelerated uplift to the accelerated melting of Icelandic ice caps.” Science has known for a long time that Earth recovers as the glaciers melt, and becomes lighter. Richard Bennet, an associate professor in geosciences at the University of Arizona explained that it is unclear whether current land-level rises are due to recent deglaciation. According to Mr. Bennett, co-author of the study: “Iceland was the first place where we could say that accelerated uplift has accelerated ice loss.” The researchers utilized a network 62 global position satellite receivers. These receivers were attached to various rocks throughout the country. Geoscientists tracked the GPS position over many years and calculated how far the rocks had traveled. Geodesy is a technique that allows you to calculate how far your rocks have traveled. According to the study, it was found that the current acceleration of uplift in Iceland is directly related to the melting glaciers and global warming. Mr. Bennett said: “What we’re observing is a climatically induced change in the Earth’s surface.” Approximately 12,000 years ago, during the last deglaciation, there is evidence that volcanic activity in some regions of the island increased thirty-fold, Mr. Bennet added. Others have also calculated that Iceland’s crust will recover from the warming-induced loss of ice. This means the number of eruptions like the one at Eyjafjallajokull, 2010,, which has had adverse economic effects globally, will increase. Geoscientists use the 62 satellite receivers to monitor the movement of the crust. Photo by Richard A. Bennett/UA Department of Geosciences. Some of these GPS receivers have been installed in Iceland since 1995.. Mr. Bennett, Sigrun Hreinsdottir, of GNS Science, Avalon (New Zealand), had placed 20 GPS transmitters in Iceland in 2006, and 2009, to increase the country’s coverage. The receivers can be found 18 miles from the five largest icecaps in Iceland. Geodesy was used by the researchers to monitor geological activity such as earthquakes, volcanic eruptions, and other forms of seismic activity. Mr. Bennett noted in 2013, that one of the stations at the centre of Iceland had been showing signs of a rapid rise. To determine if any other changes were being recorded, the team checked nearby stations. Bennett stated that the striking result was “Yes, all of them do.” “We wondered, what is the cause of this?” The team began to analyze the signals over years and discovered that uplift occurred in the area between large ice caps. Data showed that the faster the uplift rate, the further the receiver was away from an ice cap area, the more data they collected. Land uplift due to accelerated melting glaciers. Other scientists monitoring ice loss on the island noticed a noticeable acceleration in melting rates since 1995.. The records from Iceland, which some date back to the 1800s show that temperatures have increased since 1980.. Ms. Compton applied mathematical models to see if the rate of ice melt year after year would cause an increase in global warming. No. The glaciers must be melting faster each year in order to increase uplift. Ms. Compton discovered that both the rate of melting ice and the rise in temperatures closely correlated with her estimations of the date of uplift. Ms. Compton stated that she was amazed at how closely everything matched up. Mr. Bennet said, “There is no explanation for the accelerated uplift except the glacier is melting at an acceleration rate… We hope we can use GPS measurements to quantify ice loss.” Geoscientists will analyze uplift data to find seasonal variations as the ice caps melt in the summer and then grow during winter. Citation: “Climate-driven vertical acceleration of Icelandic rock measured using CGPS geodesy”, Kathleen Compton and Richard A. Bennett. Geophysical Research Letters. DOI: 10. 1002/2014GL062446.
