- Location of settlements in seismic areas, especially on poorly consolidated soils, on ground prone to landslides or along fault lines.
- Building structures, such as homes, bridges, dams, which are not resistant to ground motion. Unreinforced masonry buildings with heavy roofs are more vulnerable than lightweight wood framed structures. Dense groupings of buildings with high occupancy.
- Lack of access to information about earthquake risks.
The side figure illustrates schematically the four elements contributing to risk (chance of loss). They are
a) hazards (physical effects generated in the naturally occurring event),
b) location of the hazards relative to the community at risk,
c) exposure (the value and importance of the various types of structures and lifeline systems in the community serving the populace), and
d) vulnerability of the exposed structures and systems to the hazards expected to affect them during their useful life.