Impacts and Risks of Global Change - Impact of Global Changes on Mountains: Responses and Adaptation - page 63

Figure 3.11. Natural and socio-natural disasters in the countries of the Andean region,
1950-2009 (Source: The International Disaster Database 2010).
Color image of this figure appears in the color plate section at the end of the topic.
In this sub-region, a number of natural factors converge that allow the
development of specifi c phenomena of a certain magnitude and intensity.
In the East Pacifi c region, the continental crust of South America heaves and
rises above the oceanic crust, triggering earthquakes and volcanic eruptions.
The American west coast is part of the so-called Ring of Fire, which is one
of the most seismic areas of the world and releases more than 80% of the
global energy produced by seismic waves. It is worth noting that a number
of very serious earthquakes have taken place in this region, such as the
ones in Chile on May 22, 1960 and February 27, 2010 with a magnitude of
9.5 resp. 8.8 on the Richter scale, and the earthquake in Ecuador in 1906,
which also reached 8.8 on the Richter scale. Even though most volcanoes
are located at a reasonable distance from large cities and mostly affect
small villages and rural and aboriginal settlements, some eruptions have
had catastrophic consequences, as for example in 1859, when the volcano
Pichincha (4794 m) destroyed the city of Quito.
Another important assortment of extreme phenomena is that of hydro-
meteorological hazards. The variability of rains and droughts is closely
linked with the phenomenon known as El Niño-Southern Oscillation
(ENSO). During the El Niño phase, the trade winds weaken, permitting the
warmer water of the Equatorial Pacifi c Ocean to spread towards Ecuador,
raising the temperature of the Central and East Pacifi c Oceans by one or
two degrees. This encourages the formation of clouds and more intense
precipitation, often leading to catastrophic fl oods as in 1940, 1972, 1982,
1987, 1992, 1997, 2000 and 2005. This meteorological phenomenon fi nds its
counterpart in La Niña, characterized by cooler than usual surface water
temperatures of the Equatorial Pacifi c Ocean and producing contrary effects
to those of El Niño, i.e., droughts (1946, 1968, 1980, 1995 and 1998).
Modernization has led to the development of new technologies and
goods which, in the course of their production, utilization and eventual