Many of us have never experienced a tsunami and perhaps will never. Disturbingly, over 700 million people live in low-lying coastal areas and small island developing states are exposed to extreme sea-level events, including tsunamis.

Tsunamis are usually caused by earthquakes below or near the ocean but can also be set off by other events, like volcanic eruptions, submarine landslides, and coastal rock falls. The UN states that tsunamis are rare events but can be extremely deadly. In the past 100 years, 58 of them have claimed more than 260,000 lives or an average of 4,600 per disaster, surpassing any other natural hazard. The UN adds that the highest number of deaths in that period was the Indian Ocean tsunami of December 2004, which caused an estimated 227,000 fatalities in 14 countries, with Indonesia, Sri Lanka, India, and Thailand hardest hit.

What are tsunamis?

On November 5 each year World Tsunami Awareness Day is observed.

A tsunami is a series of enormous waves created by an underwater disturbance, usually associated with earthquakes occurring below or near the ocean. Volcanic eruptions, submarine landslides, and coastal rock falls can also generate a tsunami as can a large asteroid impacting the ocean. They originate from a vertical movement of the sea floor with the consequent displacement of water mass. The UN mentions that tsunami waves often look like walls of water and can attack the shoreline and be dangerous for hours, with waves coming every five to 60 minutes.

The first wave may not be the largest, and often it is the second, third, fourth, or even later waves that are the biggest. After one wave inundates or floods inland, it recedes seaward often as far as a person can see, so the seafloor is exposed. The next wave then rushes ashore within minutes and carries with it floating debris that were destroyed by previous waves.

What are the causes of tsunamis?

The United Nations outlines a number of factors which can trigger a tsunami, such as movements along fault zones associated with plate boundaries. Most strong earthquakes occur in subduction zones where an ocean plate slides under a continental plate or another younger ocean plate. It is important to note that not all earthquakes trigger tsunamis.

Another trigger is that of landslides. A landslide which occurs along the coast can force large amounts of water into the sea, disturbing the water and generating a tsunami. Underwater landslides can also result in tsunamis when the material loosened by the landslide moves violently, pushing the water in front of it.

A third trigger of tsunamis is that of volcanic eruptions. Although relatively infrequent, violent volcanic eruptions also represent impulsive disturbances which can displace a great volume of water and generate extremely destructive tsunami waves in the immediate source area.

One of the largest and most destructive tsunamis ever recorded was generated in August 26, 1883 after the explosion and collapse of the volcano of Krakatoa (Krakatau) in Indonesia. This explosion generated waves that reached 135 feet, destroyed coastal towns and villages along the Sunda Strait in both the islands of Java and Sumatra, killing 36,417 people.

Finally, tsunamis can be caused by extraterrestrial collision, such as asteroids and meteors, which are an extremely rare occurrence. Although no meteor-/asteroid-induced tsunamis have been recorded in recent history, scientists realise that if these celestial bodies should strike the ocean, a large volume of water would undoubtedly be displaced to cause a tsunami.

Port Royal

It is widely believed that the Port Royal earthquake on June 7, 1692 also triggered a tsunami or a series of tsunamis. According to the United Nations Educational, Scientific and Cultural Organization (UNESCO), three violent shocks ripped the earth, followed by a giant tidal wave. The report added that, within minutes, two-thirds of the entire town disappeared under water. It is reported that 2,000 people died immediately and another 3,000 died of injuries and disease shortly after.

Early Warning

In Jamaica, Old Harbour Bay is the first tsunami-ready community.

The United Nations Office for Disaster Risk Reduction (UNDRR) states that multi-hazard early warning systems are needed to monitor a range of systems to provide alerts of imminent tsunamis and other hazards, giving enough time for at-risk people to act. Additionally, the systems must be designed to go the “last mile” – ensuring the warning reaches at-risk communities.

For early-warning systems to be effective, they must be multi-hazard – detecting different hazards that may occur alone, simultaneously, or cascade. They must be end-to-end – covering everything from hazard detection to action, providing understandable and actionable warning messages. And they must be people-centred – empowering people to act on time and in an appropriate manner to reduce potential harm. Women are oftentimes the mobilisers and community participants and, therefore, equal attention must be paid regarding the training of women in disaster management.

According to experts in the field, disasters reinforce, perpetuate, and increase gender inequality, in terms of loss of livelihoods, gender-based violence, and even levels of mortality during and in the aftermath of disasters. Historically, women are often placed at greater risk due to their inability to access information as readily as men about pending disasters.

Early warning and early action save lives, yet only half of the world’s population is covered by early warning systems. People in the least developed countries and small island developing states have the least coverage. In March 2022 the UN Secretary General Antonio Guterres announced that, “The United Nations will spearhead new action to ensure every person on Earth is protected by early-warning systems within five years.” This includes early-warning systems for tsunamis. The sea is a major characteristic for Caribbean and coastal islands. As a result, those who live in these areas must be prepared for all eventualities. Governments, especially those with vulnerable populations, need to invest more in developing and implementing a national tsunami policy. Investments made in early warning systems are a litmus test for governance and sustainable development.

As citizens we must be mindful of the United Nations Sustainable Development Goal #11, which addresses sustainable cities and communities. Unfortunately, as population increases people are forced to occupy lands which are unsafe and establish unplanned settlements. Scientists have said repeatedly that tsunamis will become more destructive as sea levels rise as a result of climate change; therefore, governments must become more proactive in their approach to disaster management.

Many governments continue to struggle with the issue of squatting and unplanned settlements as oftentimes there is a political price to pay and no party, it appears, is willing to pay such a price.

Regrettably, many of us have no interest in the environment, yet mother nature impacts our lives whether we like it or not. Tsunami preparedness must be incorporated into Jamaica’s National Standards Curriculum (NSC) and instruction must begin at the primary level. Let us all make a concerted and realistic effort to help in the global tsunami awareness campaign, especially since we are all vulnerable.

Wayne Campbell is an educator and social commentator with an interest in development policies as they affect culture and or gender issues. Send comments to the Jamaica Observer or waykam@yahoo.com