Without question, the earthquake and subsequent tsunami that afflicted the Indonesian island of Sulawesi last Friday is a monumental tragedy. At the time of writing, 844 people are confirmed dead, with many more trapped among the rubble, missing, or trapped in remote regions that have yet to be properly assessed or even contacted. The construction of mass graves has been ordered.
Understanding what happened is of vital importance to every community affected by it. At this stage, though, what lessons are emerging from the way the disaster unfolded, and what can you do, as an individual, to make sure you maximize your chances of survival should you ever be in such a terrifying situation?
What Caused The Tsunami?
The latest estimates put the quake at a magnitude 7.5 event, although as is always the case with these things, magnitude alone doesn’t precisely convey how destructive, or not, each quake will be. In this case, however, it proved to kick-start a perfect storm of disastrous events. Although all the facts aren’t in yet, it seems that this quake struck at 18:03 local time, unleashing plenty of aftershocks as it did.
Landslides, along with the quake itself, has buried or otherwise collapsed plenty of houses along the zone of strongest shaking. Julia Macfarlane, an ABC News reporter, has been told by a local contact that it’s thought that more than a hundred schoolchildren in Sigi province just south of Palu were camping at the time of the earthquake, and the fear is that they’ve been buried alive.
A tsunami, which ricocheted around the region’s waters, was also produced. There’s speculation that a landslide, triggered by this coastal quake, forced a vast amount of water up the bay.
Per The New York Times, the fault that ruptured was a strike-slip fault. These are the types that move side-by-side, and they don’t usually allow for bodies of water to be pushed forward, which pile up on coastlines in the form of tsunamis. However, the fault in this case may be permitted to move vertically a little bit, meaning that it’s possible than an earthquake alone was responsible for the mass aquatic movement here.
As was spotted by geophysicist Austin Elliott, a 2017 study on the region appears to have described this exact seismic calamity to the letter. Nevertheless, careful assessment of the geological changes on and around the antagonizing fault is required before any firm conclusions can be made.
Either way, what happened next is indisputable: this body of water ultimately crashed into the city of Palu in the form of a powerful tsunami reaching crests of 5.5 meters (18 feet) high. It impacted plenty along this stretch of the shore, including those in the city of Donggala, but Palu bore the brunt of the devastation. Along with everyone in the city, plenty had congregated around the shorefront for a festival, some of which stood by post-earthquake and filmed the tsunami on their phones as it rushed towards them.
How Did The Early Warning System Perform?
There’s plenty to be said here about what happened, socially, scientifically and technologically speaking. This excellent piece by National Geographic’s Maya Wei-Hass paints a stark picture of a situation that rapidly out of control.
One key point is that the tsunami was detected by Indonesia’s meteorological and geophysics agency BMKG, but it underestimated the size of the wave heights. It’s suspected that the system did not take into account the narrow bay’s effects on the propagating water.
As it rushed towards Palu, it’s possible the increasingly narrow bay squashed the water, allowing for a huge increase in wave height by the time it reached the city limits. This isn’t a fault of the system per se, but it highlights that tsunami forecasting models should do more to take into account the unique bathymetry of their surroundings.
Initially, it was thought that the tsunami warning was lifted before the tsunami arrived. However, the latest news reports suggest that the tsunami warning was also lifted after the first waves of the tsunami arrived on shore.
In any case, several experts have stressed that the system is in dire need of better funding and an update. As reported by the Associated Press, Indonesia is currently using a prototype of an otherwise high-tech system of seafloor sensors, sound wave detectors, tidal gauges and fiber-optic cables developed using funds from the US National Science Foundation.
It really needs to complete the project, but funding delays have kicked that into the long grass. Louise Comfort, a University of Pittsburgh expert in disaster management and leader of the US side of the endeavor, told AP that the buoys are not working, and the tide gauges are limited in their ability to provide an early warning.
Several reports explain that text alerts did not go out to local populations as planned as cellphone towers were downed during the initial earthquake. This was deeply unfortunate, and suggests that such towers need to be made as earthquake-resistant as possible.
What About Those Affected By The Earthquake?
As plenty of geoscientists are pointing out, though, the early warning system is just one piece of the puzzle. Plenty would have died no matter how good the early warning system was, because that’s what happens in earthquakes and tsunamis.
I’ve previously spoken to earthquake experts about what best to do during an earthquake, and the advice is unchanging no matter where you are. You can read about it in detail here, but in summary, if you’re outside, get away from buildings and stay in the open. If you’re inside, you should drop to the floor, get under cover beneath a sturdy table, and hold on until a minute or so after the shaking has stopped.
The latter point may seem counterintuitive to those seeing footage of collapsed buildings. Nevertheless, you are more likely to survive under cover even if a building does collapse than you are running from flying debris. As Caltech seismologist Lucy Jones explained to me shortly after Indonesia’s Lombok earthquake in August, drop, cover and hold on is the best advice to most situations because it minimizes the risk from flying debris, which is the number one killer during quakes.
More people will survive if this advice is immediately adhered to as soon as the shaking is felt, but building codes have a huge influence over the final death tolls of such earthquakes. From Los Angeles to anywhere in Indonesia, plenty of buildings aren’t constructed according to modern, earthquake-proofing codes, which means collapses are likely.
Indonesia’s building codes are infamously dire, and deaths will continue to occur until they are drastically changed, no matter how cutting-edge their early warning system ever becomes.
How To Survive A Tsunami
It’s unclear how well people in Indonesia stuck to the official, internationally recognized advice for earthquakes, but the reaction to the tsunami is a different matter altogether.
This particular disaster demonstrated that even scientists were taken off-guard by the nature of the tsunami, and it’s fair to say that tsunamis vary greatly in their size and travel time. Nevertheless, the general advice as to what to do when one is heading your way remains the same.
Unfortunately, based on a handful of footage appearing to show members of the public filming the waves crash into the structures they were standing in, it appears the advice was either not heeded, or not known in the first place.
Dr Samantha Montano, a disasterologist, explains that “tourists and people who are not local to the community can be particularly vulnerable to a situation like the one in Indonesia this week because they may be unfamiliar with the risk, how to interpret warnings, and not know the appropriate actions to take.”
Geophysicists have taken to social media to point out that the early warning system is secondary to people’s instinctive behaviors at the time of the earthquake – and getting the right advice out there is of the utmost importance. That, perhaps, is the most important lesson anyone can take away from this event, no matter where in the world you happen to be right now.
According to the US Department of Homeland Security, during the event, you must first practice the aforementioned drop, over and hold on if you’re inside a building. If a tsunami is suspected, then you should move immediately to higher ground as far in land as possible.
“Listen to authorities, but do not wait for tsunami warnings and evacuation orders,” they explain. Normally, signs will indicate evacuations routes if you are in the danger zone; follow them without question. As the Red Cross underscore, “if you can see the wave you are too close for safety.” If you are in a car near the coast, get out and run to higher ground.
If you are in a boat, face the direction of the waves and head out to sea. Remember that while at sea, tsunamis are a bit like slinky toys: they have a wave motion that has a horizontal, left-right component but not a vertical, up-down component until they hit shallow ground. This means you can barely feel one go by if you’re on a boat far form shore – and they only cause damage as they pile up on shallow ground along the coast.
“Don’t listen to anyone who suggests it’s a good idea to surf a tsunami or to go the beach to watch the waves roll in,” Dr Sara McBride, a Mendenhall Fellow and social scientist at the United States Geological Survey (USGS), says. “While I can appreciate the novelty of experience and the desire to tell a great story, it’s just not worth risking your or other people’s lives who might have to come rescue you.”
After the tsunami has ended, devastation will likely surround you. Flooded areas are likely deeper than you expect, so keep out of them. Stay away from infrastructure if possible, especially if it’s damaged. Stay away from anything electric that’s submerged in pools of water. Phone lines will be jammed, so save using them only for emergencies. Do not return to danger zones unless an all-clear is given by the authorities.
As ever, preparation is key. Educate yourself. Do you live in an area prone to being impacted by tsunamis, or are you travelling to such an area? If so, make sure you sign up to any early warning systems. Memorize evacuation routes, and understand what an earthquake is like so you know when a tsunami may be approaching. Know what to do no matter where you are at the time.
Organize your family or traveling companions: have a plan of where to meet if you get separated. Be aware that aftershocks can generate new tsunamis, which may be weaker or more powerful than the one you just ran away from. Ideally, have a getaway kit, which contains key medicines, a radio, a torch, spare batteries, blankets or sleeping bags, toilet paper, face and dust masks, and drinkable water.
This advice, like that for earthquakes, has a universal quality to it. Major organizations, from the American Red Cross and the Federal Emergency Management Agency (FEMA) to the New Zealand and Japanese governments, being aware, being prepared, and escaping to higher ground – natural, not infrastructural, if possible – is the best way to improve your chances of survival.
McBride explains that there are some nuances here. “A lot of countries have similar advice, [but] there can absolutely be regional and local differences.” She notes that a familiarity with local conditions, both geologically and relating to the types of warnings you may receive and how you might receive these, are important to understand.
“I realize that looking up tsunami information might be the last thing you’re thinking about when planning a trip or purchasing a home but knowing this basic information ahead of time could save your life and the people around you,” she says.
Why Don’t People Just Run Away Immediately?
This is a deeply complicated question and an ongoing field of research. McBride points out that even if people are aware of what’s about to happen, it’s not yet clear why they don’t react in the way they should.
She says that people do tend to mill around post-event in order to gather more information. At the same time, they look to each other and try to pick up on social cues in order to inform their response. There is, of course, an innate desire to record their experiences and share these with others, “which has been exacerbated by the ease of sharing information via social media platforms.”
Although it’s clear that all these factors combine to form a huge cognitive load, the need to document things is a major issue. Not only does it put the individual’s life in jeopardy, but it also gives off social cues to others that staying behind is fine.
“My recommendation would be always ensure you are in a safe place and that you have assisted people around you first before you press record,” McBride says.
Can I Do Anything To Help?
It’s also worth remembering that, long after the headlines change to focus on something else, the disaster in the affected region is still going to be unfolding. “Once the national or international media attention leaves the affected community the needs of the community can go un- or under-addressed,” Montano adds.
With that in mind, if you’d like to help, there are several things you can do. Making sure to disseminate correct information on social media channels is vital, and pointing out blatant misinformation, unfounded rumors or fearmongering is of vital importance. You can also donate to several organizations that need all the help they can get, including the Indonesian Red Cross.
It’s also worth noting that those that survived the earthquake and tsunami will be permanently affected by the horrors they just witnessed. According to McBride, we don’t necessarily talk that often about how a disaster can affect people emotionally, mentally, or socially.”
While there is an understandable focus on tangible resources, like food, water and shelter, this type of trauma must also be addressed. “The cognitive disruption a disaster can cause is also not well acknowledged and it is something that we are still studying to learn more about.”
She points to the case of the 2011 Canterbury earthquake sequence in New Zealand, noting that a study published that revealed a significant cognitive disruption and higher anxiety rates in people affected by the disaster. It’s clear that people had a difficult time getting back to a somewhat healthy mental state, and an awareness of this will be key when the victims of the Sulawesi tragedy are met by the authorities and charity workers on the ground.