Huge mountains spewing hot lava, glowing red and covered in kilometre-high clouds of smoke. These are probably the first images that come to mind when you think of volcanoes. But volcanoes can also look very different: grey and muddy, for example. Some 130 km north of Bucharest, in the Romanian municipality of Berca, lie some of the most fascinating geological sights in Europe: the mud volcanoes of Berca. Admittedly, these are not ‘real’ volcanoes. Instead of hot lava, a fountain of cold mud and gas billows out of the bubbling earth. And this happens every few minutes.
The mud volcanoes (if you like, you can also think of them as a kind of mud geyser) are the result of unique geological activity: gases rise from a depth of up to 3,000 metres, forcing a mixture of clay soil and groundwater to the surface. This creates a crater landscape reminiscent of the moon.
The mud volcanoes were first scientifically described more than 150 years ago. Since then, geologists have returned to the region time and again. They mainly study the composition of the mud and gases that bubble out of the volcanoes. The result: the gases consist almost entirely of methane. As a result, the mud volcanoes emit almost 200 tonnes of methane per year – as much as almost 2,000 cows. But it’s not just the escaping gases that are exciting, the groundwater is also extraordinary: it is extremely salty. By comparison, the global salt content of groundwater is almost 400 times lower. This is precisely why the mud volcanoes are not only geologically exciting, but also biologically. Rare plant species that can withstand the adverse conditions have colonised the salty soil. One of these plants is the salt marsh mallow, a small shrub with warty leaves. With the help of salt glands, the plant can actively excrete excess salt and thus survive in the unusual environment.
The site is open to visitors every day – from 8 am to 8 pm in the summer season and from 8 am to 4 pm in winter. Admission costs just under 80 cents for adults and senior citizens. A little tip: anyone visiting mud volcanoes should pack spare shoes!
Photo: Mud volcanoes of Berca; Credits: Unsplash/Mihai Dragomirescu
