Fault lines – the boundaries and cracks of the Earth's tectonic plates – are where geology is most visible, where the natural world catastrophically collides with the human world.
Those that live in areas where there are active fault lines, live under the constant threat of earthquakes and landslides as the plates shift.
In 1906, San Francisco was devastated by an earthquake, which brought the city to its knees.
San Francisco, USA
An earthquake in Kobe, Japan in 1995 killed over 6000 people.
And in 2010, an earthquake struck Haiti.
The incident and aftermath was one of the worst in recorded history, an estimated 230,000 people were killed.
With more cities expanding in areas of high seismic risk, seismologists fear the death toll may rise.
Yumei Wang, Director of Geohazards, Oregon – "We're in a race against time, and the more we can get done now, the more lives we'll save."
In order to protect vulnerable communities from these natural disasters, procedures and safeguards are implemented and tested.
Emergency services routinely carry out earthquake drills.
And procedures are practised in workplaces and schools in order to save lives.
Yumei Wang, Director of Geohazards, Oregon – "Right when you feel the earthquake shaking, what we train people to do is to duck, cover and hold. Anything that might fall, won't fall on you directly – it will fall on the table, and the whole time you protect your head."
On an engineering level, stringent codes of construction now ensure that buildings are more resistant to the effects of earthquakes.
John Hooper, Structural Engineer – "The majority of the high-rises here, they'll move, and they'll move a lot. But they're designed to withstand that motion and that energy absorption... The damage should be related mainly to the non-structural components and not to the major structural elements themselves."
Construction is not permitted directly on top of active fault lines, and some buildings undergo seismic retrofitting, where they are reinforced to make them more resistant to seismic activity.
Earthquakes have the potential to cause mass destruction.
But countries that prepare for the worst may be able to avert the kind of devastation, which occurred in Haiti.