Free Report About Tenerife Volcanic Hazards Report
The Tenerife Islands are an active volcanic region with the probability for an average eruption for every 25–30 years and hence suggesting possible eruptions in the near future. Since Tenerife is densely populated and regularly visited by millions of tourists annually, there is need for a concise volcanic hazard assessment of the area to help in the reduction of any potential risks in case of a volcanic event. Volcanic eruptions comprise some of the most significant natural hazards on the island due to its diverse variety of eruption products and styles accompanied by a complex geologic and volcanic history. This paper will discuss the different hazards and risks likely to be caused by volcanoes in Tenerife with a particular emphasis on their effect on people and the environment (Blong 1984, p.24).
Risk is a term that is often misunderstood and confused with "hazard". A hazard is a potentially dangerous event, such as a lava flow, a falling volcanic bomb or a pyroclastic flow. Risk is the likelihood that somebody or a property will be killed, injured or damaged by volcanicity (Heiken & Mccoy 2000, p.2).
One of the most probable volcanic hazards in Tenerife at the moment to begin with is lava flows. The Pico Viejo and Teide stratocones together with the Northeast and Northwest Rifts are some of the products of lava flows of the most recent eruptive phase in the island that was initiated as a result of the lateral collapse of its northern flanks, the Icod–La Guancha Valley and Las Cañadas Caldera. These will generally have little danger risk to people compared to their adverse effects on traffic, property as well as communication. This is because lava flows have probable paths, whose predictions can be estimated with its diversion measures. Viscous lava does not usually advance far but instead piles above active vents like lava domes (Tilling 1989, p. 25). The may continually collapse generate dangerous hot block and ash flows and hot surges and blasts.
Figure 1: Diagram illustrating a lava flow
Secondly, Tenerife similarly stands to experience massive damages and loss of lives from likelihoods of the injection of poisonous and lethal gases into the atmosphere from the volcanic activities of the Piton del Teide volcano. Piton del Teide has vents often in continuous eruption that may result in the transportation of the acid aerosols released from the vent before being absorbed as microscopic salt particles and on tephra (Tilling 1989, p. 25). Chlorine, sulfur compounds and fluorine are some of the gases which when released can react to form poisonous acids that have the potential of damaging the skin as well as causing adverse respiratory disturbance to the existent populations. Furthermore most of these volcanic gases are usually noxious as they also smell bad and have a huge potential of causing mass fatalities. One major problem with this risk hazard is the fact that an efficient early warning system is difficult as it is short. There is therefore need for proper investigations on instances of such eruptions together with a keen observation of some of the respective locations.
Figure 2: Figure showing how gases are released from a volcano.
Ashfalls are yet another type of volcanic hazard in Tenerife that has a high probability of occurrence most especially from Pico de Teide together with other vents of the Teide that have been severally erupting in the island since 1402. Ashfalls may have little risk to people in Tenerife due to their negligible direct effect to endanger life but has the potential of damaging properties like houses and other buildings and structures. There are however instances when they can lead to loss of lives when they cause the collapse of roofs together with houses as a result of the weight of the ash load. The industrial and agricultural activities in the area are some of the sectors that also stand to experience considerable destruction and damage (Lockwood & Hazlett 2013, p. 44). Some of the appropriate mitigation measures for tephra falls in Tenerife can include the proper preparation and planning by the government for any future occurrences through clearing tephra from roofs when they begin to accumulate. Structural measures like the designing roofs that have steep slopes can also help to prevent the tephra from collecting on top of the flat roofs. Furthermore, the walls and roofs of the different houses in susceptible regions can be strengthened. Respirators can also be worn with wet pieces of clothe over the nose and the mouth.
The towns Arafo as well as Candelaria together with Santa Cruz de Tenerife suffer the probability of experiencing episodes of low-density and pyroclastic flows from the Las Canadas caldera which has been associated with some of the most significant and destructive hazardous types of volcanic eruptions. Pyroclastic flows usually consist of different types of volcanic ash and gases which generated during many volcanic eruptions. These are usually as hot as 900°C moving swiftly with velocities of several 100 m/s. As a mitigation measure, early warning is virtually impossible and hence the need for appropriate preparedness mechanisms. Dangerous situations can develop if the pyroclastic flows are generated on glacier or snow that is covered with volcanoes which may lead to melting. Therefore, here the only effective risk mitigation method is evacuation before eruption from all the areas with a probability of being affected with the pyroclastic flows.
According to the geology of Teide, there are of rift zones which form large areas of the island that face the risk of removal as a result of catastrophic landslides resulting from volcanic activity. Due to the gravitational instability of the large island, there is a high likelihood for the occurrence of the landslides. The northern section of Teide has been experiencing a series of significant slumps that have been deposited into the ocean in the past. Also called lahars, volcanic debris and mud flows are also a major type of volcanic hazard that has potential risks for both property and people. Lahars often proceed fast enough possessing a significant amount of great destructive power. They can develop from either a direct effect of a volcanic eruption, when for example; crater lakes are blown out or as a consequence of heavy rainfalls both during and after eruption. To mitigate against this volcanic hazard and risk, there is therefore the will be need for the Tenerife Government to establish early warning systems against people from staying close to the Teide mountain. Areas occurring farther ought to be warned several hours in advance (Rose 2006, p.23). A sufficient monitoring of individual volcanoes, however, rarely is guaranteed. Small lahars can be diverted by barriers or by artificial channels which lead them away from valuable land or property, but in most cases the volume and force of the lahar is such that it beyond human power to control (Rose 2006, p.23).
Figure 3: This is an example of hazard map.
The Tenerife Government should therefore employ both the topographic as well as geological hazard mapping to help provide for detailed knowledge on the characteristics and history of the specific volcanoes (Papale 2014, p. 446). Hazard maps will help to indicate the eruption pathways and products that can be expected like pyroclastic or lava flows for different eruption intensities. For dangerous volcanic locations, appropriate and efficient emergency plans together with evacuation plans in the case of immediate danger to the population can be worked out.
BLONG, R. J. (1984). Volcanic Hazards A Sourcebook on the Effects of Eruptions. Burlington, Elsevier Science. Retrieved from: http://public.eblib.com/choice/PublicFullRecord.aspx?p=1838105.
HEIKEN, G., & MCCOY, F. W. (2000). Volcanic hazards and disasters in human antiquity. Boulder, aColo, Geological Society of America.
LOCKWOOD, J., & HAZLETT, R. W. (2013). Volcanoes Global Perspectives. New York, NY, John Wiley & Sons.
PAPALE, P. (2014). Volcanic hazards, risks and disasters. Amsterdam, Elsevier. Retrieved from: http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk& =485226.
ROSE, W. I. (2006). Volcanic hazards in Central America. Boulder, Colo, Geological Society of America. Retrieved from: https://www.lib.umn.edu/slog.phtml?url=http://www.gsajournals.org/perlserv/?request=g et-specialpub-toc&isbn=0-8137-2412-0.
TILLING, R. I. (1989). Volcanic hazards. Washington, D.C., American Geophysical Union.