Tectonic hazards frequently occur the world over but this does not always result in a risk. There are three aspects that eventually cause the disaster and these are: the tectonic event itself, exposure to that event and whether you are vulnerable to its effects or not. Only when all three of these criteria are satisfied does a tectonic disaster occur. The first of the three cannot be mitigated against by humans as we cannot stop a volcanic eruption or an earthquake occurring. The second factor, exposure is becoming an increasingly more worrying issue as global population continues it’s current, rapid rise. As populations increase, settlements start to expand into regions of regular tectonic activity. This close proximity to the tectonic event increases exposure and hence, the risk of a tectonic disaster occurring. Mexico City is a prime example of where rapid population growth has occurred despite the overlying threat of disaster. The city, with a population of over 21 million, has experienced rapid expansion during the second half of the 20th Century despite being built on top of unconsolidated alluvial sediments. These help magnify the effect of seismic waves in the extremely seismically active region which only serves to worsen the impact of potential earthquakes. Over 5,000 people were killed in September 1985 when a category 8 magnitude earthquake hit the region but this did not seem to deter potential immigrants. The third factor that contributes to earthquake risk is the vulnerability to an earthquake and this is the area that can be most easily mitigated against although, an authority’s ability to do so is massively dependent on their economic position.
Mitigation against a tectonic disaster has three components: plan, prepare and respond. In order for a government to be able to do these, they must have first have the correct perception of the event, they must be able to perceive the danger and understand the need for mitigation. They must also have sufficient wealth available to them in order for them to successfully mitigate which is why there are such large disparities between mitigation levels in developed and developing countries.