* Seismic Hazards - Impacts & Responses

What are the primary impacts of seismic events?

A direct result of the hazard, e.g. people can be killed when a tsunami hits a coastal area.

What are secondary impacts of seismic hazards?

They occur as a result of the primary impacts, e.g. earthquakes can break gas pipes, causing fires.

What can earthquakes do to buildings? (Social impact)

They cause buildings to collapse, killing and injuring people, and leaving others homeless.

What can earthquakes and liquefaction cause? (Social impacts)

They can cause gas lines and power lines to break, starting fires that kill more people.

Broken water pipes can cause flooding, and lack of water can make it hard to put fires out.

What other social impacts can seismic hazards have?

• Lack of clean water can cause disease to spread.

• Tsunamis can flood large areas, killing people and causing widespread damage to property.

What impacts can earthquakes have on the economy? (Economic impact)

Can destroy business premises through ground shaking and liquefaction.

This damages the economy of the region and the country.

What other economic impacts can seismic hazards cause?

• Damage to industry may mean the country has to rely on expensive imports of goods and energy.

• Damage to buildings and infrastructure can be very expensive to repair.

What can happen to industrial units due to seismic hazards? (Environmental impact)

Industrial units, including power plants, can be damaged by earthquakes and tsunamis, causing leaks of chemicals or radioactive material that damage the environment.

What other environmental impacts can seismic hazards have?

• Fires started by damaged gas and electricity lines can destroy ecosystems.

• Tsunamis can flood freshwater ecosystems, killing plants & animals and salinising water and soil.

What may governments have to do following a seismic event? (Political)

May have to borrow money to repair damage, putting the country in debt.

Money that is earmarked for development may have to be spent on repairing damage rather than on development.

What are short-term responses?

They occur immediately before, during or immediately after the hazard.

What do short term responses to a seismic hazard include?

Rescuing people from collapsed buildings after an earthquake, and evacuating people from areas at risk from a tsunami.

What are long term responses designed to do?

Mitigate the impacts of future hazards by managing the risks.

What does prevention of seismic hazards look like?

It’s not possible to predict most seismic hazards.

However, what can be possible with prevention of seismic hazards?

Can prevent them posing a risk to people.

e.g. authorities can prevent land that is prone to liquefaction from being built in, or build giant sea walls to prevent tsunamis hitting land.

What is preparedness about?

Preparing an area and the people who live there for a future seismic hazard.

What can authorities install for preparedness?

Earthquake waning systems - these detect weaker seismic waves that may be a sign of a more powerful earthquake to come.

What do earthquake warning systems do?

They send out warnings by e.g. TV, radio and SMS.

What can individuals and businesses do as part of preparedness?

They can have plans for how people should respond during an earthquake e.g. staying away from buildings if possible, finding a strong door frame or desk to shelter under if inside.

What can authorities develop in preparedness?

Tsunami warning systems and make sure evacuation routes are well signposted.

What can communities do as part of preparedness?

Set up search and rescue teams or fire response units to tackle the impacts of a hazard.

What can be done to buildings as part of adaptation?

• Can be designed to withstand earthquakes

• Can be designed to reduce vulnerability to tsunamis

How can buildings be designed to withstand earthquakes?

By using strong or flexible materials, or by building special foundations that absorb an earthquakes energy.

How can buildings be designed to reduce vulnerability to tsunamis?

Tall, strong buildings allow people to escape the tsunami quickly, and buildings with raised, open foundations are less likely to be damaged.