Thousands of people died after a powerful earthquake hit Turkey and Syria on Monday (6/2).
A search and rescue operation is underway, with specialist teams arriving from around the world.
However, people in some hard-hit areas say relief has been slow. Some had to dig with their bare hands to find relatives.
How to start a search and rescue operation?
When first responders arrive at an earthquake site, they assess which collapsed buildings are most likely to contain trapped people.
They do this by looking for “voids”—spaces under large concrete beams or stairs where survivors can be found.
The possibility of a building collapsing further must be taken into account, as well as other hazards such as gas leaks, flooding and hazardous items such as asbestos in roofs.
As rescue teams try to reach survivors, support workers watch the movements of the collapsed structure and listen for strange sounds.
Buildings that have completely collapsed are usually the last to be searched, as the likelihood of finding survivors is very small.
The work of rescue teams is coordinated by an agency, usually the United Nations (UN) and the host country. Rescuers are specially trained and work in pairs or larger teams, while local people are often involved as well.
What rescue equipment is needed?
To remove the rubble, rescue teams use heavy machinery — including excavators and hydraulic jacks.
Large concrete slabs on the outside of buildings can be pulled out by bulldozers, allowing first responders a view of anyone trapped inside.
Video equipment on the end of flexible poles can be passed through openings to help locate survivors.
Specialized sound equipment can detect the faintest of noises within a few meters. Silence at the scene is required as a member of the rescue team knocks three times and waits to hear a response.
Carbon dioxide detectors can be used to find unconscious survivors. These work best in confined spaces, as they detect the highest concentration of CO2 in the exhaled air of those still breathing.
Thermal imaging equipment can be used to locate people who are not directly in the rescuer’s line of sight, because body heat can heat the surrounding debris.
What do rescue dogs do?
Using their sense of smell, specially trained dogs can pick up signs of life where human rescuers cannot.
Dogs can also cover large areas quickly, speeding up the search and rescue process.
Do people need to use their own hands?
With the large slabs and structures removed, rescue teams use their hands and small tools such as hammers, picks and shovels, as well as chainsaws, disc cutters and rebar cutters — which can be used to break through metallic bars in reinforced concrete.
They have protective gear including helmets and gloves to protect their hands as they remove sharp pieces of rubble.
However, in some areas of Turkey — where rescue efforts have been slow and machinery is unavailable — local people are digging through the frozen, wet rubble with their bare hands.
Bedia Gucum, owner of a restaurant in Adana, in southern Turkey, told the BBC: “We need thick work gloves to move the rubble with our hands. Because once they hear someone alive in there, all the heavy machinery stops and they have to dig with their hands, and that is beyond human ability”.
How is the end time of an operation decided?
This decision is made between the UN coordinating agency and the central and local government of the host country.
Search and rescue attempts are usually called off between five and seven days after a disaster, after no one is found alive for a day or two.
However, it is known that people were rescued alive beyond that moment.
In 2010, a man was found alive after 27 days trapped under rubble following an earthquake in Haiti.
In 2013, a woman was pulled from the ruins of a factory in Bangladesh, 17 days after it collapsed.