More than half of the ice cover in Turkey has vanished since the 1970s, a mountainous country with an average elevation of 1,132 meters above sea level.
Half of Turkey is covered by mountains and hills. Glaciers now exist on three volcanoes, in the high peaks in the Southeastern and Middle Taurus Mountains, and in the Eastern Black Sea Mountains. However, the glacier coverage was much larger in the 1970s, according to a study from Ege University in Turkey and NASA’s Goddard Space and Flight Center. Over more than 40 years, the total glacial area fell from 25km2 in the 1970s, to 10.85km2 in 2012-2013. Five of the glaciers have completely vanished.
The research team, led by Doğukan Doğu Yavaşlı, professor at department of Geography at Ege University, updated the previous studies of Turkish glaciers from 1970s to 2012-2013, and published their findings in Remote Sensing of Environment.
The researchers observed the decline of Turkish glaciers via Landsat satellite data. The Landsat program delivers the longest continuous global record of the Earth’s surface. Since the 1970s, Landsat satellite and its successors have provided consistent and stunning images of the Earth for researchers and scientists to closely measure changes in the Earth’s landscape. Landsat sensors are characterized by moderate spatial resolution—course enough for global coverage, and clear enough to capture large-scale human activities such as urbanization.
From the Landsat images showing Mount Süphan, a dormant volcano, the glacial part over the mountain has shrunk more than 70% since the 1970s. The current remnant glacier is so small and fragmented that it is challenging for scientists to distinguish the ice from debris.
The ice cap on Mt. Ağrı is the highest (5,137m) and largest glacier in Turkey, which we have covered in a previous Photo Friday. located along Turkey’s eastern border, Mt. Ağrı is also known as Mt. Ararat, the national mountain of Armenia, where it was located until World War I and where it still plays a significant role in culture. Through interpretation of the satellite data, the researchers discovered that from 1977 to 2013, most glacial retreat took place on the southern, western and eastern glacier aspects, all at lower elevations. Ice loss on the northern part is comparatively minimal.
Most glacial retreat can be attributed to climate change and its impact on rising summer nighttime and minimum temperatures, the researchers found. They found that there were no variations in precipitation or cloud cover that could explain the high rates of glacier retreat since the 1970s.
The combination of Landsat and commercial satellite data greatly improved the study of glacier change as well as climate change implications in Turkey during this period.
“Without Landsat’s long record, studies like ours would be impossible to undertake, because we don’t have a time machine to go back to the 1970s and 1980s and see how Turkey’s glaciers were doing then. Using Landsat and commercial satellite data together, we can map glaciers with high accuracy. It’s a powerful combination for studying the Earth from space,” said Compton Tucker, one of the researchers of the study.