Volcanoes and volcanic eruptions are words we associate with enormous release of earth's energy, which results in a change to the face of the Earth. They usher us back to distant ages when the Earth was a lifeless planetary body when fire and water raged.
Everyone today knows about burning volcanoes made of magma with its liquid or molten rock. Scores of films have documented their activities, as have hundreds of books, and thousands of scientific papers. This is only natural since magmatic volcanoes are not only exotic phenomena, but they also provide a view deep into the interior of the Earth which is virtually inaccessible to us by any other method
"Mud volcanoes," also known as "sedimentary volcanoes" or "gas - oil volcanoes," are close cousins to magmatic volcanoes. Just like magmatic volcanoes, they can erupt powerfully and hurl flames to great heights (sometimes even several hundred of meters). They spew out millions of cubic meters of hydrocarbon gases and tons of mud. Mud volcanoes also exist on the floor of the sea and can form islands and banks that alter the topography and shape of the coastline and even trigger earthquakes.
Another feature of mud volcanoes is their direct relationship to oil and gas fields. Mud volcanoes resemble super-deep exploration wells in the sense that they are direct indicators of hydrocarbons at great depths and provide valuable information on the formation and migration of oil and gas. Both mud volcanoes and hydrocarbon fields are the result of a single process of oil and gas formation, which has a characteristic vertical zone with methane gas forming in younger strata, overlying a zone of intense formation of oil and fatty gases.
What are Mud Volcanoes?
Mud volcanoes are essentially channels for releasing pressurized gas and mineral water, sometimes with traces of oil, together with associated mud from great depths (812km) and depositing them on the surface of the earth where they form mounds ranging from 5 to 500m high. In both appearance and behavior, they outwardly resemble a magmatic volcano. The explosive release of pent-up gases combined with the burning of hydrocarbon gases adds to this similarity. But, unlike their magmatic cousins, which carry molten rock or larva or enormous heat to the surface, mud volcanoes in Azerbaijan are at ambient temperature and may even be cool.
Volcanoes are characterized by a constant activity of domes, gryphons (cones) and salses (pools). Some are dry in nature; others, wet. Normally they don't form distinctive volcano shapes as magmatic volcanoes do. Rather, they just flow down into the surrounding plains. They often peak at about 1020 m but can spread across a surface of several kilometers. Among the largest mud volcanoes in the world are Boyuk Khanizadagh and Turaghai. Both are located in Azerbaijan.
Because of the softness of the rock, mud volcanoes on a geological timescale are considered to be rather ephemeral. The mud or breccia quickly erodes with wind and rain into systems of gulleys and ridges fanning out from the crater margins. Indeed a tell-tale sign of a mud volcano is its deeply grooved and often very attractive flanks. Mud volcanoes in the sea, of course, erode quickly with wave action.
Mud volcanoes are often created at points of weakness in the Earth's crust, along fault lines. They are associated with geologically young sedimentary deposits and the presence of organic gas from hydrocarbon deposits. Worldwide there are some 700 known mud volcanoes. About 300 of them exist in Eastern region of Azerbaijan and in the Caspian Sea.
While there is some dispute about the origins of mud volcanoes, geologists generally agree on some of the aspects of the formation and activities. Eruptions can occur when mud and sand are squeezed upwards by seismic forces. Here gravitational forces and tidal action appear to play a role. The sudden release and upward expansion of dissolved gases may also play a key role.
The total annual volume of gas emitted by all the volcanoes in Azerbaijan is estimated at 20 million square meters per year however, the greatest volume of gas is released when major eruptions occur such as the Turaghayi volcano in 1946. Based upon the height of its flames and its duration which lasted several hours, an estimated 500 million cubic meters of gas were released.
The life of a volcano extends over a long geological interval and is characterized by both active and extinct phases.
Dormancy, which occurs between eruptions, may take place every three or four years as the one at Lokbatan did or up to 80-90 years as with Bozdagh. Some 50 volcanoes have been erupting in the eastern region of Azerbaijan during the past 200 years since documents were kept.
The fact that mud volcano eruptions take place outside centers of population and because they erupt unexpectedly and are relatively short in duration, it's rare for them to be observed from beginning to end. An exception however was Lokbatan.
The Institute of Geology of the Azerbaijan Academy of Science has studied mud volcanoes and has discovered that the one at Lokbatan has erupted the most often - 20 times since its history has been recorded. Lokbatan means 'place where the camel got stuck'. It may well have been named after the twin humps at the crest of the hill, which give it a camel-like shape. Lokbatan is located 15 kilometers south of Baku. This mud volcano erupted in 1977 and again, even more spectacularly on October 10, 2001. Here are some of the eyewitness account as reported by BBC [Clare Doyle].
Are Mud Volcanoes Safe?
Fortunately mud volcanoes occur away from populated centers and don't usually result in disastrous consequences. However, cases have been known where they have caused serious damage and loss of life.
According to local residents, a volcanic eruption which took place in Bozdagh about 88 km northeast of Shamakhi resulted in the deaths of six shepherds who happened to be camping overnight in its crater. About 2,000 sheep in their flock were also killed.
There are legends surrounding the destruction of an entire settlement known as 'Old Gliady' from an eruption that took place in the 15th century.
An eruption on the island of Sangi-Mughan (Svinoi) in 1932 and the subsequent fireball that enveloped the entire island killed the lighthouse keeper, his family and some other local inhabitants. Fortunately, such events are extremely rare, but the message is clear: Don't build too close to mud volcanoes. Such advice would have been well heeded by those who built too close to the edge of the Baku reservoir of Jeyranbatan which was destroyed by a mud flow in 2002.
It should be noted that Lokbatan is also an oil reservoir and the vicinity supports many State Oil Company of Azerbaijan Republic (SOCAR) oil derricks which have been producing oil for more than 50 years. While the intermittent eruptions don't seem to affect oil productivity, explosions and clastic missiles do pose an ongoing threat to surface facilities and equipment. The gas condensate platform for Shah Deniz, one of BP's project, is located adjacent to an extinct subsea mud volcano. Geological studies have indicated that its proximity should not pose any significant risk.
Geologists describe mud volcanoes as capricious, and are still arguing about exactly how they are formed. Some believe they are created during the sedimentary process itself, while others argue that there are other influences at play as well, including seismic activity.
To the non-geologist, the explanations can seem, well, as "clear as mud". The arguments about their origins only add to the aura of mystery that surrounds these unusual and enigmatic phenomena.
Azerbaijan's mud volcanoes definitely should be part of any tourist's itinerary. So many of them are within close proximity to Baku, especially those at Alyat, Gobustan and other locations. Mud volcanoes come in a variety of shapes and sizes, but those most common in Azerbaijan have several small cones, or vents. These small cones are an amazing and even beautiful sight. They emit cold mud, water and gas. They are often characterized by rude gurgling noises to the delight of children. On hot summer days, the gryphons and salses provide them with hours of entertainment. (Suggestion: take plenty of clean clothes, plastic bags for muddy clothes, and your own supply of water to wash off afterwards.)
Chemically, volcanic mud is composed primarily of silica (5570 percent). In addition, the mud has been found to contain quantities of curative properties (iodine, bromine, calcium, magnesium, organic acids and aromatic hydrocarbons - to name just a few). As the mud solution has no significant toxic substances, it has been recommended as a curative agent for mud baths and use at spas. Just as in the Russian towns of Feodosia and Kerch, there is potential for Azerbaijan to develop its own spas from this volcanic mud.
With the limited number of tourists that visit Azerbaijan today, the volcanoes are not under any serious threat. However, with their distinctive 'lunar' landscape, scientific interest, tourist and spa potential, there is the possibility that one day too many tourists could lead to inevitable degradation and damage. Mud volcanos are themselves unique monuments and need to be protected for future posterity. The process has already begun as 23 mud volcanoes were designated for protection recently.
If you're planning a trip to Azerbaijan you may be interested ▶ Azerbaijan highlights - For those who prefer to go unbeaten path, to explore less visited places and check national charisma of this small country in Southern Caucasus on the edge of Europe.