Tsunami Preparedness: Understanding the Warnings and Staying Safe

 

Recent concerns about a potential tsunami reaching Thailand, following earthquake activity near India's Nicobar Islands, have been allayed by the Department of Mineral Resources and the Meteorological Department.

 

Both agencies have confirmed that the recent tremors will not impact Thailand or trigger a tsunami.

 

However, even without an immediate threat, it's crucial for the public to understand the signs of an impending tsunami and how to react. Here's a guide to identifying warning signals and the measures to take.

 

 

The Three Key Tsunami Indicators

The Department of Mineral Resources highlights that one of the most critical warning signs of a tsunami is a sudden and unusual drop in sea level. This phenomenon occurs due to the immense pull of a forming giant wave.

 

Typically, an underwater earthquake exceeding magnitude 7.5 can generate a tsunami. The seismic activity causes the seabed to shift, displacing vast amounts of water.

 

This pushes some water upwards and simultaneously draws water away from the coastline before it builds into a powerful wave that crashes ashore.

 

Waiting to see the towering waves before evacuating can be fatal, as these deep-water waves travel rapidly in all directions before they hit the coast with devastating force.

 

Recalling the tragic 2004 tsunami, Thailand was struck by waves reaching up to 15 metres high, travelling at an average speed of 36-45 kilometres per hour.

 

This is significantly faster than the average human running speed of 20 kilometres per hour. Therefore, in tsunami-prone areas, recognising warning signs and knowing what to do is paramount.
 

 

Spotting a Tsunami Threat: What to Look For

• Notification of a large undersea earthquake from a reliable authority.
• An abnormal and sudden retreat of the sea from the coastline.
• The sight of a wall-like wave crest approaching.

 

 

 

 

Immediate Actions When a Tsunami Threat is Present

If you are on the beach and feel the ground shake, evacuate the area instantly. Head to a designated safe zone following tsunami evacuation routes, aiming for ground higher than a three-story building.

 

If you are on a boat at sea during a tsunami, stay in deep waters. Do not attempt to return to shore until authorities confirm it is safe.

 

The Department of Disaster Prevention and Mitigation is fully prepared for tsunami events, utilising warning towers in high-risk areas. These towers issue three distinct audio signals:

 

M2 Tsunami Warning: Possible Tsunami Due to Underwater Quake

Upon detection of an undersea earthquake that could generate a tsunami, the warning towers will broadcast: "Attention, attention. An underwater earthquake has occurred, and a tsunami may follow. Please move away from the beach as quickly as possible to higher ground. Attention, attention. An underwater earthquake has occurred, and a tsunami may follow. Please move away from the beach as quickly as possible to higher ground." This message is repeated to urge immediate evacuation from coastal areas. Do not delay or wait for further confirmation, as a tsunami can arrive within minutes.
 

 

M3 Tsunami Alert: Tsunami Confirmed

Should monitoring systems confirm a tsunami is actively forming and moving towards the coast, the warning will change to: "Attention, attention. A tsunami has now occurred. Please move away from the beach as quickly as possible to higher ground. Attention, attention. A tsunami has now occurred. Please move away from the beach as quickly as possible to higher ground." This is a critical alert, demanding the most urgent evacuation possible.

 

 

M9 Meteorological - All Clear: Situation Normal

Once authorities determine the situation is safe and no further waves are expected, the warning towers will announce: "Attention, attention. The situation has now returned to normal. Please continue to assist those affected. Attention, attention. The situation has now returned to normal. Please continue to assist those affected." This signal confirms it's safe to return, while ongoing support for those affected should continue.

 

 

Beyond Warnings: Essential Preparedness

Beyond understanding the audio signals, personal preparedness is equally vital. Always have an emergency kit ready, containing essentials like medication, drinking water, important documents, and other necessities for immediate evacuation.

 

If you notice an earthquake, observe unusual animal behaviour (like restlessness or fleeing), or witness a rapid and unusual drop in sea level, move away from the coast as quickly as possible – at least 3 kilometres inland, or evacuate to high ground at least 15 metres above sea level.

If you are evacuating to a tall building, choose a sturdy, stable building of four storeys or more without waiting for official instruction.

Familiarise yourself with safe evacuation routes in your community, paying close attention to Tsunami Evacuation Route signs, tsunami sirens, and designated safe elevated areas. This knowledge is crucial for rapid escape in a real emergency.

Practice evacuation drills regularly with your family and community. These drills are highly effective in building familiarity and readiness for a real-life event.

Develop a household emergency plan. Discuss evacuation procedures with family members, designate a meeting point in case of an emergency, and ensure everyone understands their roles. This will make the evacuation systematic and safer.