Twenty years have now passed since a massive earthquake and subsequent tsunami devastated communities across Southeast Asia, resulting in more than 220,000 confirmed deaths and millions displaced following the historic event.

On the morning of December 26, 2004, a magnitude 9.2 earthquake violently shook the seabed off Indonesia, sending a 100-foot wall of water onto communities around the Indian Ocean.

Countries such as Indonesia, Sri Lanka, India and Thailand were hardest hit, with entire villages collapsing and being washed away.

Survivors faced isolation and illness as initial rescue and relief efforts were inadequate due to the overwhelming scale of the disaster.

At the time, US President George W. Bush remarked that the scale of the losses was unimaginable, as some governments were accused of delaying emergency response.

In the years following the disaster, the international community raised more than $13 billion in donations, making it the largest humanitarian response to a natural disaster.

Researchers who have studied the region and visited areas affected by the Boxing Day tsunami say signs of the disaster are still visible decades later.

Experts have noted that affected regions remain economically behind compared to areas not affected by the waves, and many survivors are still living with post-traumatic stress.

FAULT THAT TRIGGERED THE 7.0 EARTHQUAKE OFF CALIFORNIA, WHICH CANNOT PRODUCE RESPECTIVE TSUNAMIS

What caused the earthquake and could it happen again?

According to the US Geological Survey, the historic earthquake was caused by the subduction of the Indo-Australian tectonic plate beneath the Eurasian plate.

The region, known as the Sunda Trench, is highly seismic and has produced several earthquakes over magnitude 7.0 since 2004.

Statistically speaking, a magnitude 9.0 earthquake occurs along the fault only once every few hundred years to over 1,000 years; However, seismologists warn that the interval between such events can be very irregular.

The National Earthquake Information Center estimates that about 12,000 to 14,000 earthquakes occur worldwide each year, but only a small minority are felt by people on the surface.

Earthquakes with a magnitude of 8.0 or greater are considered “major quakes” and occur only every two years along the thousands of fault lines around the world.

What is a tsunami?

Is the region better prepared for a tsunami?

After the 2004 disaster, millions of dollars were spent modernizing and establishing tsunami warning systems that were not widely available before the event.

Buoys have been deployed to detect changes in sea levels, sirens for evacuations have been installed in some coastal areas and education is now part of the preparation curriculum.

One of the many systems in use is the Indian Ocean Tsunami Warning System (IOTWS), which became fully operational in 2011.

Despite the investments, the United Nations admits there are still large stretches of coastline around the world that may be unprepared for a similarly devastating event.

The goal of the Decade of Marine Science for Sustainable Development is to prepare 100% of vulnerable communities for the tsunami by 2030.

“Disasters can strike at any time. Always stay alert by paying attention to your surroundings, understanding potential dangers, recognizing natural warning signs and knowing escape routes to a safe location. You have to stay strong,” said Syarifah Nargis, a survivor of the 2004 tsunami disaster, recently shared with UNESCO.