EARTHQUAKES - Technical Hazard Sheet - Natural Disaster Profile
Earthquake can be defined as the shaking of earth caused by waves moving on and below the earth's surface and causing: surface faulting, tremors vibration, liquefaction, landslides, aftershocks and/or tsunamis.
Aggravating factors are the time of the event and the number and intensity of aftershocks.
Compound hazards are fire, landslide, and tsunami.
Factors of Vulnerability
- Location of settlements in seismic areas and size of the population.
- Inadequate building practices and regulations.
- Dense concentration of building with high occupancy.
- The absence of warning systems and lack of public awareness on earthquake risks.
Public health impact of earthquakes
The main public health threats vary according to the magnitude of the earthquake, the nature of the built environment and the secondary effects of the earthquake (eg. tsunamis, landslides and fires). The effects can be summarized in terms of how they relate to risk factors as follows:
Immediate health impact
- Trauma-related deaths and injuries from building collapse.
- Trauma-related deaths and injuries from the secondary effects of the earthquake (drowning and physical trauma from tsunamis, trauma from landslides, burns and smoke inhalation from fires).
Medium-term impact on health
- Secondary infection of untreated wounds.
- Increased morbidity and risk of complications related to pregnancy, deliveries and newborns due to interrupted obstetric and neonatal services.
- Potential risk of communicable diseases, particularly in areas affected by overcrowding.
- Increased morbidity and risk of complications of chronic diseases due to interruption of treatment.
- Increased psychosocial needs.
- Potential environmental contamination by chemical/radiological agents following destruction of industrial infrastructure.
Impact of earthquakes on the health system
- Damage to health facilities and transport infrastructure, with subsequent disruption of service delivery, leading to reduced access to and functionality of all levels of health services.
- Absence of health workers who may not be able to reach the health facilities that are still functional, or whose homes and families may have been directly affected by the earthquake.
- Reduced ability to pay for health services as affected households lose assets and livelihoods.
- Loss of medical supplies and interrupted procurement systems, with many stock-outs.
Mitigation and preparedness for earthquakes
- Strengthen health emergency risk management systems.
- Limit the risk of exposure to earthquakes by improving the quality of the built environment, with better land-use control, including regulating building.
- Ensure that health facilities are resilient to hazards, and that they are able to remain functional and able to respond to increased and changed health needs after earthquakes, with staff trained appropriately.
- Be prepared to mobilize medical response teams, including establishing temporary health structures and field hospitals.
- Invest in community preparedness – communities are often the first responders.