|Chabahar Mud Volcano|
Photo by Amirhossein Nikroo
Mud volcanoes are a less terrifying, but still dangerous cousin of magma volcanoes. They are also known as sedimentary volcanoes and gas-oil volcanoes. These volcanoes occur where there are deep deposits of gas and oil beneath the surface. There seems to be a connection with fault lines as well. Like magma volcanoes, mud volcanoes have dormant and active phases. During their active phases, they do not spew liquid hot rock and ash while causing massive earthquakes and lightning storms, but they are capable of spewing fire and enough mud at such a rate to displace or even kill human beings.
If you want to see a mud volcano, Azerbaijan in Eurasia is the place to go. There are no active magma volcanoes in the area, but there are hundreds of mud volcanoes. In fact, Azerbaijan has most of the mud volcanoes on the planet–more than half. However, most of the mud volcanoes there only emit small amounts of cool mud and gases. They can be between 16 feet and 1,640 feet tall. People do not live close enough to them to be affected by active mud volcanoes in Azerbaijan, but that is not the case in other parts of the world.
In 2006, a mud volcano became a problem in a residential area of Sidoarjo, Indonesia. The volcano appeared, erupted and the resulting mudflow killed thirteen people. Thousands have been forced from their homes by what has become known as the Lusi Mud Flow. The mudflow continues to this day. Interestingly, this extraordinarily large and dangerous mud volcano may not be a natural occurrence. Researchers have reason to believe that a local gas exploration well caused the volcano. Somehow, the pressure created led to a vent opening up and pouring excessive amounts of mud into the area.
There is still a lot to learn about mud volcanoes. They have not been studies as extensively as their noisy and deadly cousins have. We do know that built up pressure beneath the surface is involved in the birth of mud vents. We also know that they do not cause as much damage as magma volcanoes, though they can produce earthquakes and balls of fire. Because it appears they can be triggered by careless drilling, there will doubtless be much more research into what exactly causes them and how we humans can avoid being one of these causes.
Mud Volcanoes in Azerbaijan, retrieved 12/29/10, azerb.com/azmud_volcanoes.htm