Volcanos may not generally be considered a threat to information systems, however the devastating effects that they can cause to populated areas stand as testimony to the power that they have. Modern society relies heavily on information systems for both business and personal use and any small disruption in these systems may cause economic losses. People who live and work near active volcanos have to worry about volcanic eruptions destroying their posessions and perhaps their businesses.
This paper will define what a volcano is and explain the different types of volcanos, how they form, and the effects of eruptions. This paper will also provide examples of recent volcanic activity to attempt to show where people and businesses are most vulnerable to this attack by nature.
In the All.net database a volcanic attack against information systems is defined as "a volcano erupts causing physical damage and permanent as well as temporary faults, requiring emergency response, and otherwise disrupting normal operations. Volcanic eruptions usually involve the expulsion of magma, volcanic ash, and rock fragments. Lava flows can cover many miles, while volcanic ash can stay in the air to cover hundreds of miles. Both lava and ash can cause problems with information systems. A lava flow can level a building containing computers and servers, it can cover power lines and power plants, cutting off electricity to the entire affected area, it can destroy phone lines, and it can burn down homes and businesses. Earthquakes, tsunamis, and landslides are also associated with volcanic activity and can cause devastation of their own.
When discussing volcanos it is best to start with a basic explanation of plate tectonics. The Earth consists of seven large plates and many smaller plates, all moving in different directions. The activity of these plates cause three different types of margins: divergent, convergent, and strike slip.
Areas where plates are moving away from each other are called divergent margins. Rifts form in these areas, most of which occur under the oceans, as magma rises up to form new oceanic crust. Normal faults can also occur here from the "slumping" of land masses. The major ridges are the Mid-Atlantic Ridge, the Pacific Rise, and the Indian Ocean Ridge. The Mid-Atlantic ridge cuts across Iceland and this is the only location where a divergent margin can be seen on land. Divergent margins are areas of volcanic activity as magma is forced up to the surface through the "crack" in the crust. Since these ridges are located under water the volcanic activity that occurs there is less of a threat to humans living on land.
Areas where plates are moving towards each other are called convergent margins. In these areas one of the plates, usually the oceanic one, is forced under the other in a process known as subduction. The plate which is subducted undergoes an increase in pressure and temperature as it moves further under the surface. At some point the rock which the plate is composed of begins to melt and this becomes the magma which can fuel a volcano. The area above this magma chamber undergoes orogeny (mountain-building) from the pushing up of the land mass, causing thrust faults, and rock fragments scraped away from the subducting plate. These areas are also prone to earthquakes, especially in the region where the plates meet and in the subducted plate underneath the upper plate.
Areas where plates are moving in opposite directions where no convergence or divergence is occuring are called strike slip zones. These areas are prone to earthquakes and volcanos are not usually found there. The faults in these areas are called transform faults, and one of the most famous is the San Andreas fault in California. The North American plate is moving Northwest, at a greater degree to the west, than the Juan De Fuca Plate is moving. Los Angeles is located on the North American Plate, while San Francisco is on the Juan De Fuca Plate. This plate tectonic activity accounts for the earthquakes that commonly occur there.
There are many different types of volcanos. The most common ones are cinder cones, lava domes, shield volcanos, calderas, and stratovolcanos. The type of volcano depends on several factors, one of the more important being the viscosity of the magma. Cinder cones and lava domes are formed from more viscous lava and their slopes are more steep than volcanos formed from more fluid lava, such as shield volcanos. Stratovolcanos (or composite volcanos) get their name from the alternating layers of ash and solidified lava that make up their structure, since the volcano erupts in alternating flows of ash followed by lava. Calderas typically form after a large eruption where the structure can no longer support itself from the loss of material, causing collapse. Other types of volcanos include somma volcanos, tuff rings and maars.
Other effects of volcanic eruptions include tsunamis and landslides. Tsunamis are very large tidal waves, often caused by submarine earthquakes as well as volcanos, and can be more than several meters high. They can occur when land is uplifted or slumped by a volcanic eruption and the water in the ocean is displaced. Tsunamis will race across the ocean and when the water becomes more shallow the height of the tsunami will increase, causing devastation when it reaches land. Landslides occur when the force of the eruption or earthquakes shake the rock material which forms the volcano. The material will disintegrate into many smaller pieces which are loosened from the volcano. This material can be cohesive if there are enough small (clay-sized) particles or if the material is wet from heavy rainfall. It will cascade down the slope and move away from the volcano destroying everything in its path.  Landslides and tsunamis are just two examples of effects of volcanic activity. This is of course in addition to lava flows, pyroclastic blasts and flows, the debris that is projected from the volcano, and the layers of ash that will eventually settle upon the region.
One of the most famous volcanic eruptions is that of Mount Vesuvius in Italy. The volcano erupted in 79AD and the towns of Pompeii and Herculaneum were buried by the pyroclastic flows and ash that settled upon them. Pompeii was buried under 10 feet of tephra, a variety of materials which settle after a volcanic eruption, and Herculaneum was buried under 75 feet of ash. Vesuvius is a stratovolcano although its history indicates that it started out as a somma volcano 300,000 years ago, making it a complex volcano (a volcano composed of more than one type).
This volcanic eruption became well known because of the invaluable information that archaeologists were able to obtain from these cities. It was also the first volcanic eruption to be witnessed, recorded, and described in detail in known written history. The eruption of Mount Vesuvius occurred so quickly that the people living there were unable to escape its devastation. The everyday life of these people was literally carved in stone since the ash, tephra, and pyroclastic flows covered the area, preserving it. Archaeologists were able to obtain a large amount of information from these sites regarding the daily activities of people during the Roman period, making it a great, yet sad, discovery.
It is highly unlikely that a volcanic eruption this devastating would occur in modern times. Geologists have a greater understanding of plate tectonics, volcanos and earthquakes and although they still remain unpredictable, it is possible to observe warning signs and evacuate cities surrounding the volcano. The people in Pompeii and Hurculaneum did not understand that the increase in earthquakes before the eruption was an indication of the events to come as we do now. However, imagine what would have happened to computers, networks, servers, phone systems, cable systems, etc. in Pompeii and Hurculaneum if they did exist at that time. Archaeologists hundreds of years from now might have been able to make another great discovery.
In October and November, 2002, Mount Etna in Italy erupted. Mount Etna is Europe's most active volcano and is located on the island of Sicily. These most recent eruptions caused the airport in Catania to close down because of the thick clouds of ash produced by the volcano. In addition, lava flows forced the evacuation of some people in the towns of Linguaglossa and Piano Provenzana.
In January, 2002 Mount Nyiragongo in Congo erupted covering almost half the city of Goma with lava. This volcanic activity displaced hundreds of thousands of people and almost completely destroyed the business district of the city, causing many people to lose their business, as well as their homes. The city's electricity and running water systems were destroyed as well.
In July, 2001 the Mayon volcano in the Philippines erupted sending lava and ash towards the town of Malabog. Four hours before the eruption the residents of the town started evacuating the city and fortunately there were no casualties. The nearby city of Legazpi was effected by the clouds of ash eminating from the volcano. The rain in the city turned to mud as it mixed with the ash and the sky became darkened from the clouds. A larger eruption may have caused much more devastation to the city and without the early warning signs the citizens of Malabog would have been in much more danger.
In December, 2000 the Popocatepetl volcano, just south of Mexico city erupted, prompting the evacuation of nearly 30,000 people from areas surrounding the volcano. Lava, ash and other debris were projected from the volcano. The location of a nearby glacier was a concern to authorities as they feared that the eruption might cause the breakup or melting of parts of the glacier, potentially triggering mudslides. Fortunately this did not happen and there was no damage or casualties reported, most likely because of the evacuation efforts.
In August, 2000 Mount Oyama erupted in Japan on Miyakejima Island, located just over 100 miles from Tokyo. The eruption prompted the evacuation of over 2,000 residents. There were no injuries, but the ash which exploded from the volcano covered some parts of the island up to about eight inches. The close proximity to Tokyo raises the concern that a very large eruption of any volcano in the region may cause damage in to the city. Any major devastation that occurs there will certainly have an effect on the entire world.
All information systems, computer networks, servers, power lines, etc. in the path of lava flows will be completely destroyed by a volcanic eruption. Likewise, tsunamis, landslides, earthquakes and other after effects of volcanic activity can cause complete destruction of these systems. The ash which will settle from the air surrounding the volcano can reach for miles, and although it may not cause major damage, it will still need to be cleaned up and removed from all areas. Since information systems are sensitive to dust anyway, ash from volcanos has the capacity to cause severe damage.
The attack of volcanos can be prevented by not living near a volcano. However, for some people and businesses that is not practical. Volcanos occur in many places and they are simply something that those people have learned to live with. Geologists, although unable to predict volcanic activity with complete certainty, can read some of the warning signs indicating that an eruption may take place, sometimes saving lives though evacuation. Things that are immovable will still be destroyed if an eruption does take place, but people and businesses may be able to take with them everything they need to save their information if enough time is provided.
 Cohen, Fred, All.net Security Database, Available at: http://all.net/CID//Attack/ Attack8.html [This database contains information on threat types, attack methods and defense methods relating to information systems. It also provides links for each different type and method to others showing how the information is connected.]
 United States Geological Survey, Available at: http://geology.er.us gs.gov/eastern/plates.html [This website has a great map showing the different plates.]
 Decker, Robert and Decker, Barbara, Volcanoes, W.H. Freeman and Company, 3rd Edition, 1998 [This is a book about volcanos. It contains chapters on basic geological information on volcanos, ash, lava, bombs, and other effects of volcanic activity. It also contains detailed chapters on several different volcanos throughout the world.]
 The Physics of Tsunamis, University of Washington, Earth and Space Sciences Department, Available at: http://www.geophys.washington.edu/tsunami/general/physics/physics.ht ml [This website has general information on tsunamis.]
 United States Geological Survey, Volcano Hazards Program, Available at: h ttp://volcanoes.usgs.gov/Hazards/What/Landslides/landslides.html [This website has information on different volcano hazards, and this specific link leads to a page which discusses landslides in relation to volcanos.]
 Vesuvius, Italy, University of North Dakota, Available at: h ttp://volcano.und.nodak.edu/vwdocs/volc_images/img_vesuvius.html [This article contains general information on the eruption of Mount Vesuvius in 79AD.]
 Cable News Network, November 25, 2002, Available at: http://www.cnn.com/2002/TECH/science/11/25/etna.threat/index.html [This article is about the eruption of Mount Etna in November, 2002.]
 University of North Dakota, Available at: http://volcano.un d.edu/vwdocs/current_volcs/etna/ [This article contains a history of the eruptions at Mount Etna.]
 Cable News Network, January 26, 2002, Available at: h ttp://www.cnn.com/2002/WORLD/africa/01/26/congo.water/index.html [This article is about the eruption of Mount Nyiragongo in the Congo, which occurred in January 2002.]
 Cable News Network, January 18, 2002, Available at: http://www.cnn.com/2002/WORLD/africa/01/18/drcongo.volcano/in dex.html?related [This article is about the eruption of Mount Nyiragongo in the Congo, which occurred in January 2002.]
 Cable News Network, July 25, 2001, Available at: http://www.cnn.com/2001/WORLD/asiapcf/southeast/07/25/phil.vo lcano/index.html [This article is about the eruption of the Mayon volcano in the Philippines in July 2001.]
 Cable News Network, December 19, 2000, Available at: http://www.cnn.com/2000/WORLD/americas/12/19/mexico.volcano.04/in dex.html [This article is about the eruption of the Popocatepetl volcano in Mexico in December 2000.]
 Cable News Network, August 21, 2000, Available at: http://www.cnn.com/2000/ASIANOW/east/08/19/japan.volcano/index.html [This article is about the eruption of Mount Oyama in Japan in August 2000.]