Picture of the day for July 1, 2018

Mud flow at Berca Mud Volcanoes, a geological and botanical reservation located close to Berca, Buzău County, Romania. The phenomenon is caused by gases that flow from 3,000 metres (9,800 ft) deep towards the surface, through the underground layers of clay and water. They push up underground salty water and mud, until they overflow through the mouths of the volcanoes, where the gas emerges as bubbles. The blur in the middle of the channel is caused by a wave of mud that passes approx. every 20 seconds.. Learn more.