Rơi, Che phủ, và Nắm chặt: Cách Phản ứng Đúng

The Drop Cover Hold Technique Step by Step

Drop, Cover, and Hold OnThe internationally recommended protective action during earthquake shaking. Drop to your hands and knees, take cover under sturdy furniture, and hold on until shaking stops. is the globally recommended protective action for people caught indoors when earthquake shaking begins. It was developed through decades of earthquake casualty research and replaces older — and demonstrably dangerous — advice such as standing in doorways. The technique is simple enough to execute in the two to three seconds between feeling the first tremor and the onset of violent shaking, which is why drilling it to the level of automatic reflex is critical.

Step one: DROP to your hands and knees immediately. This position lowers your center of gravity, prevents you from being thrown to the floor, and still allows you to move if needed. It is far more stable than standing, and studies of earthquake casualties show that most injuries result from falls caused by loss of balance rather than direct structural impact.

Step two: Take COVER under a sturdy table or desk. Position yourself with your back to the table's underside and your head and neck protected by your arms if no table is available. Move toward interior walls away from windows if you are in an open area. The cover position protects the head and neck — where injuries are most lethal — from falling objects and shattering glass.

Step three: HOLD ON to the table leg with one hand and protect your head and neck with the other arm. Tables will move during strong shaking; holding on ensures you move with the table and maintain protection throughout the event. Keep your knees bent and feet planted to absorb movement. Maintain this position until all shaking has completely stopped, even if the pause between waves feels like the earthquake is over.

Why Under a Table Is Safer Than a Doorway

The doorway myth persists in popular culture despite being thoroughly refuted by Earthquake PreparednessThe ongoing process of planning and preparation to minimize earthquake impact, including securing furniture, creating communication plans, maintaining emergency supplies, and practicing drills. research and structural engineering data. The advice originated with early 20th-century adobe structures in which doorways were one of the few reinforced sections of a building. In modern wood-frame and steel-frame construction, doorframes offer no special structural protection. Standing in a doorway exposes you to injuries from swinging doors, broken glass in adjacent windows, and falling objects, while preventing you from reaching cover under a table.

Structural analysis of collapsed buildings consistently shows that the void space beneath sturdy furniture provides effective protection in the range of structural damage most people are likely to experience. In a complete structural collapse — which is rare in buildings constructed to post-1980 codes — neither a doorway nor a table will guarantee survival. The goal of Drop, Cover, and Hold OnThe internationally recommended protective action during earthquake shaking. Drop to your hands and knees, take cover under sturdy furniture, and hold on until shaking stops. is to protect against the far more common scenario: objects falling from shelves, light fixtures, and ceilings during strong but non-collapse-level shaking.

The "Triangle of Life" technique, which advocates crouching beside large furniture rather than under it, has been studied and rejected by structural engineers and emergency management professionals. It relies on assumptions about collapse geometry that do not hold for the range of building types in which most people live and work. Official guidance from FEMA, the American Red Cross, the USGS, and emergency management agencies worldwide is uniformly in favor of Drop, Cover, and Hold OnThe internationally recommended protective action during earthquake shaking. Drop to your hands and knees, take cover under sturdy furniture, and hold on until shaking stops..

Adapting the Technique: Wheelchair, Bed, Outdoors

People who use wheelchairs should lock the wheels immediately, lean forward with their face down, protect their neck and head with their arms, and remain in the chair for the duration of shaking. If the chair cannot be locked, brace it against a wall or interior corner. After shaking stops, visually assess the exit path before moving, as debris may block wheelchair routes.

Waking up during nighttime shaking presents a specific challenge because decision-making is impaired during sleep inertia. The recommended action when shaking wakes you in bed is to roll out of bed onto the floor beside it, then cover your head with a pillow or your arms. Do not attempt to run to another room or go under the bed; the time required to do so exceeds the window before violent shaking arrives, and the risk of falling is substantial.

Outdoors, the modified Drop, Cover, and Hold OnThe internationally recommended protective action during earthquake shaking. Drop to your hands and knees, take cover under sturdy furniture, and hold on until shaking stops. technique involves moving away from buildings, trees, streetlights, and power lines — all of which can topple or shed debris — and then dropping to the ground in an open area. Do not attempt to run indoors during shaking because crossing a threshold while the structure is moving dramatically increases the risk of falling or being struck by the door frame. Stay on the ground with your head protected until all shaking stops.

Common Mistakes During Earthquake Shaking

The most dangerous mistake is attempting to run, either out of the building or to another room. Human reaction time under surprise stress is approximately 0.2 to 0.5 seconds, and the biomechanics of running on a moving floor make falls nearly inevitable. Research on injuries sustained during the 1994 Northridge and 1989 Loma Prieta earthquakes showed that a significant proportion of serious injuries occurred to people who were moving at the time of shaking rather than in a Shelter-in-PlaceThe practice of staying in your current location during or after an earthquake rather than evacuating. Appropriate when the building is structurally sound and there is no tsunami risk. position.

Attempting to retrieve valuable objects — a laptop, a phone, a pet — during shaking is another common and dangerous impulse. The seconds spent reaching for an object are seconds not spent protecting your head and neck. Valuables and pets should be secured in pre-earthquake Earthquake PreparednessThe ongoing process of planning and preparation to minimize earthquake impact, including securing furniture, creating communication plans, maintaining emergency supplies, and practicing drills. planning, not retrieved during an event. Once you are in the Drop, Cover, and Hold OnThe internationally recommended protective action during earthquake shaking. Drop to your hands and knees, take cover under sturdy furniture, and hold on until shaking stops. position, your sole objective is to maintain it until shaking stops.

Standing under overhead objects such as hanging plants, ceiling fans, and light fixtures is a third common error. These items become projectiles during strong shaking even if they do not fall completely. Move away from overhead hazards as part of your initial drop movement, choosing the nearest sturdy furniture for cover rather than the nearest spot on the floor.

What to Do Immediately After Shaking Stops

When shaking stops, remain in place for a count of sixty before rising. AftershockA smaller earthquake that follows the mainshock in the same fault region. Aftershock sequences can last weeks to years, with the largest aftershock typically 1.0-1.2 magnitudes below the mainshock. sequences often include a large aftershock within the first minute of a mainshock, and rising prematurely from cover has caused injuries in multiple historical events. Once you are confident that shaking has fully stopped, begin a systematic assessment: check yourself for injuries, then check those immediately around you.

Look before you move. Assess the floor around you for broken glass, fallen objects, and structural debris before standing. Put on shoes before walking through damaged areas — glass cuts are among the most common injuries in the hours following an earthquake. Open doors carefully and check that the ceiling above the frame is intact before stepping through.

Check for gas leaks by smell (a sulfur or rotten-egg odor) and by listening for hissing near appliances and pipes. If you suspect a leak, do not use any electrical switches, open flames, or phone equipment that generates a spark. Leave the building, leaving the door open, and call the gas company from outside or from a neighbor's home. Know the location of your main gas shutoff valve before an earthquake occurs — this is a core element of Earthquake PreparednessThe ongoing process of planning and preparation to minimize earthquake impact, including securing furniture, creating communication plans, maintaining emergency supplies, and practicing drills. planning.