A deadly threat
Loss burden dependent on many factors
The Fukushima nuclear disaster of 2011 in Japan was triggered by a tsunami following an earthquake — The costliest natural catastrophe of all time
More than 90% of all earthquakes occur in regions where large tectonic plates meet. Many active volcanoes are to be found in the same regions.
In convergent zones, oceanic plates push themselves under continental plates. This is called a subduction zone, for example off the South American Pacific coast.
In the case of transform faults, on the other hand, tectonic plates push against each other in a side-to-side motion. An example of this is the San Andreas Fault in California.
Owing to the different degrees of stress build-up, convergent zones produce the strongest earthquakes (Chile, 1960; Sumatra, 2004), followed by transform zones (San Francisco, 1906), and divergent zones. Since the hypocentre of quakes on convergent plate boundaries is often in the sea, these strong quakes account for less than 30% of overall global earthquake losses. There is a significant risk they will trigger a tsunami.
Nine out of ten earthquakes occur in regions where large tectonic plates meet
The loss generated by an earthquake is determined not only by the earthquake parameters themselves (magnitude, distance, duration), and the local subsoil conditions, but also by the characteristics of the affected buildings: type of design, type of building, occupancy, year of construction, height, asymmetries in the floor and elevation plan, resonant frequency (Mexico City effect), and other factors.
Stronger earthquakes frequently cause knock-on effects with high loss potentials. These include seismic sea waves (tsunamis), such as those that caused such devastation in the Sumatra quake of 2004 or in the Japan quake of 2011. They can also cause landslides, subsidence and ground liquefaction, which can produce extremely high losses.
Overall losses from earthquakes worldwide 1980-2018
Loss prevention is key
Earthquake insurance is generally taken out as a supplement to traditional fire insurance cover or as a component of an EC (extended coverage) policy. Substantial deductibles to limit indemnity and loss accumulation are a precondition for the insurability of the earthquake risk. Compared with windstorm, earthquake (like flood) has only attained a low level of insurance penetration in global terms.
Poorer countries in particular require a massive increase in earthquake insurance in order to lessen the financial impact of quakes and to speed up reconstruction. To help realise this, Munich Re has been a supporter of the Global Earthquake Model since 2007.
GEM is a joint initiative started by leading geo research centres, the private sector and international organisations. Its main objective is to draw up a risk model for each country, thus making it possible to estimate loss potentials and the benefits of loss prevention measures, and ultimately increase insurability. Such an initiative had never existed before, especially for emerging and developing countries.