Today’s Image of the Day from NASA Earth Observatory features the Vatnajökull ice cap in Iceland. When the photograph was taken in July, the snow cap was not its natural white color, but was stained with gray and brown
The image was acquired on July 13, 2022 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite.
The surfaces of Tungnaárjökull and nearby glaciers had darkened. Without new snowfall, the color persisted throughout the month, explains NASA.
“Ash from volcanic eruptions has darkened Vatnajökull periodically in the past. But in July 2022, the volcanoes of Iceland were all quiet. Instead, windstorms likely lofted sand and mineral dust from the ground onto the ice cap. Scientists have estimated that about 4.5 million tons of dust comes to rest atop Iceland’s glaciers each year,” says NASA.
“Iceland’s climate is not hot or dry, but it can still be a dusty place. On average, the country sees 135 ‘dust days,’ in which at least one weather station on the island detects dust. Much of it comes from heavily eroded areas at the fronts of glaciers, but also from sandy deserts. Together these dusty surfaces cover nearly a quarter of the country.”
Vatnajökull has been gradually losing ice. According to NASA, this ice has shrunk in volume by about 15 percent in the past century. However. it is still the country’s largest ice cap, spanning approximately 3,000 square miles.
Image Credit: NASA Earth Observatory