One of the basic concepts in emergency management is the cascading event, an event that occurs as the result of an initial event. A good example can be found in Hurricane Katrina where the hurricane missed making landfall in New Orleans but led to the failure of floodwalls and levees in over 50 locations. The result was major flooding in 80% of the city up to 10 feet in some locations. We saw the same in San Francisco in 1906 where the earthquake did significant initial damage but then sparked a series of fires that burned for several days and destroyed over 80% of the city.
The problem with examples like these is that they tend to make us think of disasters as strictly localized events. In Managing for Long-term Community Recovery in the Aftermath of Disaster, authors Daniel Alesch, Lucy Arendt and James Holly identify ripple effects that affect the external environment as well as the affected community. These ripple effects have consequences for the external environment and in turn produce ripple effects that can have consequences for the affected community. For example, Hurricane Katrina produced problems for communities hosting refugees from the disaster which in turn had an impact on New Orleans as many of these people opted to make new lives in the host communities. Likewise, insurance payments following the 1906 earthquake and fires in San Francisco led to a market contraction that in turn contributed to the financial Panic of 1907.
However, the recent eruption of a volcano on Iceland’s Reykjanes peninsula should serve as a warning that these examples pale in comparison to the cascading events that can be created by volcanoes. We tend to think of volcanoes as localized events. Volcanoes certainly can produce horrific local events due to pyroclastic flows (a dense, fast-moving flow of solidified lava pieces, volcanic ash, and hot gases) and lava but these affect a limited area. The real potential for widespread cascading events lies in the volcanic ash produced in explosive eruptions. Unlike normal wood ash, volcanic ash is composed of sharp angular particles of rock. This has a detrimental effect when inhaled by humans or animals, can contaminate food and water supplies, and affect machinery and electronic devices. Volcanic ash clouds can reflect solar radiation and absorb land radiation, leading to cooling temperatures and, in extreme cases, volcanic winter.
An example of the potential impact of a volcanic eruption is the 2010 eruption of Eyjafjallajökull, Iceland. The resulting ash cloud spread over parts of Europe and forced the cancellation of approximately 100,000 flights, costing the aviation industry some $2.6 billion. Note that this was not a particularly significant eruption. There have been far worse.
There have been five significant mass extinction events or “die-offs” in pre-history that had significant impact on life on earth. Largely considered the worst was the third occurring in the Permian – Triassic Period some 250 million years ago. This event saw the extinction of 81% of all marine species and 70% of all terrestrial species. Overall, estimates of the extinction rate have been as high as 95%. The cause? Increased volcanic activity leading to volcanic winters.
While this is an extreme example, there are numerous and more recent examples of how volcanic eruptions have the capacity to change history. The volcanic eruption of the island of Thera in 1628 BCE may have contributed to the end of the Minoan and there are suggestions in Chinese records that it may have produced a volcanic winter. The eruption of the Samalas volcano in Indonesia in 1257 CE altered the world’s climate, causing damp, cold winters in 1258-59 that resulted in widespread crop failures and famine. A similar situation occurred in 1816 when the eruption of Mount Tabor in 1815 caused what became known as the “Year Without Summer” with resulting crop failures and famine. As recently as 1991, the eruption of Mount Pinatubo in the Philippines caused a global temperature decrease of .9°F (.5°C) for roughly 3 years. There are many more examples of the effect of volcanic ash on climate that in turn produces social change.
Of even greater concern are the roughly 60 “supervolcanoes” scattered around the globe. A supervolcano is a volcano that has had a past eruption with a volcanic explosivity index (VEI) of 8. A VEI of 8 is the highest recorded magnitude on the scale and the eruption creates a volume of 240 cubic miles (1000 cubic kilometers). The magnitude of such eruptions would cause significant impacts to climate, technology, and health. A 2014 paper by the United States Geological Survey demonstrated that the ash cloud from an eruption of the Yellowstone volcano would cover most of the United States within a month.
Clearly, such events will require major response on both the national and international level. So, what can a local emergency manager do? The answer is simple: we do what we have always done: assess risk and mitigate what we can.
One of the biggest things we can do is to be cognizant of the facts and share them with the public. For example, while the Yellowstone supervolcano has received a lot of play in the doomsday media, the USGS website points out that the volcano is behaving within historical norms and there is no indication of an imminent eruption. Furthermore, an eruption would most likely consist of lava flows. If you have a risk of volcanic activity in your jurisdiction, liaising with volcanologists is essential.
With regards to mitigation, there are lessons to be learned from the events such as Mount St. Helens about the impact of ash deposits on emergency vehicles and personnel and the unique demands on recovery operations. For example, volcanic ash tends to harden with the consistency of concrete when wet. It can affect transportation, as we saw in 2010, agriculture, electrical and telecommunications systems, water treatment facilities, and anything that relies on air filtration: vehicles, furnaces, air conditioners, etc. Like any other risk, there are things that can be done to protect our capacity to respond and to limit harm to the public.
Like any other risk we deal with, volcanic activity must be considered but it must also be put into context. We cannot plan for every disaster in detail, but we can be cognizant of its risk and factor it into our all-hazards planning as appropriate. Remember that all-hazards planning doesn’t mean “plan for everything;” it means “be prepared to respond to anything.” There’s a big difference between the two.
Comments
You can follow this conversation by subscribing to the comment feed for this post.