In the first of a new weekly blog post, GeoJames looks at the natural geographical and geological wonders of the world (WotW). The series of weekly posts will venture to all four corners of this magnificent planet, exploring national parks, areas of scientific interest and stunning scenic backdrops. We begin in Azerbaijan with an rather unusual geological phenomenon.
Most people are familiar with the natural seepage of oil and natural gas along active tectonic regions, whether it be as volcanic edifices on continental margins, or deep sea vents along passive margins. But some of the greatest concentrations of seepage have been observed in mud volcanoes.
The Gobustan State Reserve in Azerbaijan, 15km outside the capital city Baku, is home to over 400 of these mud volcanoes, over half the world’s total, and have become an essential stop on Azerbaijan’s tourist trail. The spectacular mud cones form in a similar manner to igneous shield volcanoes, and there is strong agreement amongst geologists that mud volcanoes are associated with geologically young material. Azerbaijan’s mud volcanoes can measure 10km in diameter and reach heights in excess of 700m (like the Boyuk Khanizadagh found in Azerbaijan).
Unlike their volcanic cousins, whose eruptions are driven by sub-surface magma, the mud volcanoes of Azerbaijan are visible signs of oil and gas beneath the Caspian region, breaking out through cracks that emerge at the surface. Without a sub-surface heat source the mud volcanoes of Azerbaijan emit very cold mud, water and gas almost continually.
Despite the apparent calmness of mud cones, they can be as violent as a magmatic eruptions (see video above). It is thought that the larger cones erupt violently every twenty years or so. From what is currently understood, gas is ignited deep below ground resulting in what can be a spectacular explosion above ground. The last major mud volcanic eruption was in October 2001 at Boyuk Khanizadagh in Azerbaijan in 2001.
There was a big explosion, and a huge flame started coming from the hillside. It looked as though an animal was trying to get out of the ground. The flame was unbelievably big, about three hundred metres high. It was surrounded by dense, black smoke, and lots of mud was being thrown into the air. – Witness on 10th October 2001.
One shepherd and 400 sheep were reported to have perished. Fortunately, catastrophes like this are incredibly rare. In fact, for most of the year, tourists and geologists alike bathe in the volcanoes mud, hoping to experience the reported therapeutic benefits.
The mud volcanoes of Azerbaijan’s Gobustan State Reserve are certainly a sight to behold, and one to experience in the future. Little is known about their internal working, making these icons of Azerbaijan’s Caspian coast even more mysterious.