Geophysicist Vasil Gurev: Minor Changes in Temperature Can Change Glacier Melting Speed Dramatically
When people see a photo of the Antarctic and of glaciers, usually they picture a still, cold and immovable world, but actually it is not like that. Glaciers have their own life, they live, evolve and move. Minor changes in temperature can drastically change their speed of melting, said geophysicist and glaciologist Vasil Gurev of the Physics Faculty of the Sofia University, a longtime member of the Bulgarian Antarctic Institute and participant in the 31st Bulgarian Antarctic Expedition. Within its framework Gurev has been working on a two-year project about complex geophysical studies of glaciers near the area of the South Bay and the Bulgarian Antarctic Base St Kliment Ohridiski. The project is headed by Gergana Georgieva, who is already wrapping up her field work on Livingston Island.
"In its upper part, the so-called the accumulation zone, the glacier grows when snowing. Gradually snow turns into firn and later into ice. This process continues for years and even decades depending on the place and conditions. In one year a glacier could accumulate significant mass as it is related to a number of factors, depending on the average temperature in the respective region," the geophysicist said.
"In the second half of 20th century the region of the Antarctic peninsula and the South Shetland Islands underwent a significant increase in the average temperature, four times more compared with neigbouring regions. At the end of the last century and the beginning of this century this trend downturned. For the last 20 years of the past century the temperature in the region of Livingston Island increased by 0.32 C every ten years, but at the end of the century and in the following years the temperature decreased slightly. This has prompted scientists to ask the question how glaciers react to this cooling," he said.
Gurev added that in the region of Livingston Island there are glaciers, monitored for fifteen years, which significantly dropped the speed at which they are losing mass. This means that within 10-15 years they have sensed this drop in temperature in the region and reacted to it.
"Minor changes in temperature can significantly change the speed of melting. If the average temperature in the bottom section of the glacier of 0.3C falls to - 0.2C, the melting decreases abruptly. It is thought that these are the main reasons why these glaciers react relatively faster, decreasing the speed at which they are losing mass," said Gurev.
"It is hard to predict what will happen during the next decades but some of the scientific reports say that the 15-year long colder period is coming to an end. However, several more years have to pass in order for the new trend to emerge," the geophysicist said.
(to be continued)
BTA's Daily News editor Konstantin Karagyozov is the only member of the media who is travelling on board the ship to Livingston Island and back, and will cover the Bulgarian expedition on site throughout the stay in Antarctica. All media outlets can use the Bulgaria-Antarctica BTA's Log for free.