1er A magnitude 7 earthquake shook the island of Haiti in January 2010. 280,000 people died, 300,000 people were injured and more than a million people were left on the streets. “During the earthquake, there was no seismic network to record it. We then tried to develop it with on-site researchers and managed to fund a number of conventional seismic stations, ”explains Éric Calais, a professor in the geosciences department at the École Normale Supérieure (read his interview below in the table).
A “low cost” network.
But in 2015, when a new earthquake hit the island and killed fifteen people, none of those stations worked. In fact, its establishment in a country like Haiti faces economic and knowledge challenges that are difficult to solve in the short term. So we had to look for something else …
In 2018, the researcher discovered a small device that cost a few hundred euros, a free data seismometer based on a cheap Raspberry Pi computer and capable of transmitting data in real time. “My Haitian colleagues and I had the idea of acquiring ten of these units in order to create a network of ‘low cost’ seismometers,” the scientist continues.
Given the difficulty of working only with on-site government institutions, it seemed necessary to complete seismic coverage by other means. It is in this perspective that the citizen approach became evident. “There is a lot of talk about the gap between science and society. I think we need to find smart ways to close this gap. This is even more important in Haiti because there are no regulations on natural hazards. And trying to find people who can act as ambassadors for your community with seismometers is key, ”says Eric Calais.
More than 1,000 localized replicas
In 2019, therefore, a network of citizens was set up, hosts of homes, spread across the country. And on August 14, 2021, everything worked out as expected. Publication published in March in the journal Science validates the idea that citizens equipped with Raspberry Shake (RS) in Haiti can provide enough reliable information to establish a real earthquake monitoring network, without conventional stations. “The on-site experiment allowed us to show that the results obtained with RS are consistent with those of conventional stations and those derived from satellite data,” explains Éric Calais.
The “earthquake-citizen” data showed more than 1,000 aftershocks in the three weeks following the earthquake. In addition, the machine learning applied to the data of the citizen seismometer closest to the main shock allowed a prediction of the temporal evolution of the aftershocks, an important data to organize the emergency response. It is, above all, a “socio-seismology” project, which aims to bring citizens and seismologists closer to a network in which everyone feels a partner.
“The ambition is above all to test the acceptance of a seismological measurement system based on citizens. Our paradigm shift is that the network is not just a set of devices in the territory but above all a network of men and women who they are involved in a joint effort to provide information, ”concludes the researcher .. A device that could be spread all over the world.
It is a mini-computer equipped with a geophone, a sensor, usually tubular in shape, that can record and measure the speed of seismic vibrations through the ground. Seismological data from seismometers is stored on a microcomputer that manages the Internet connection, sends the data, and makes simple graphs for users. Everything fits in a box of 10 cm by 10. The data is freely accessible to everyone on the site: ayiti.unice.fr/ayiti-seismes
“For reliable information, you need an open dialogue”
The point of view Eric Calais, Professor of Geosciences (ENS) and Research Director (IRD)
Could other countries develop such a low-cost surveillance network?
Yes, you can imagine this device in addition to the existing conventional network. In America, one could imagine that in Nicaragua, El Salvador or Guatemala. But we can also develop this network in the countries of East Africa, Ethiopia, Kenya or Tanzania. Asia is not left out either, there is currently a network of Raspberry Shake in schools in Nepal.
Your experience shows that citizen science projects are not just for rich countries. How do you persuade the people of Haiti to take an interest in it?
What we see here is that when we talk to the locals there is a real and sincere demand for information about earthquakes. Many people were, and still are, traumatized by the 2010 disaster.
Fellow sociologists interviewed the hosts of our stations and pulled out some elements: they all say they want accurate information about the magnitude and exact location of the earthquake. However, this information cannot exist without an efficient network.
In addition, the hosts want to participate in something for their country, they want to produce information. The third element is the distrust of the citizenry towards the state, which in Haiti cannot carry out its basic missions.
Solutions must be found in the face of failures and this network is one of them. We try, with our fellow humanities, to open a dialogue with the hosts about the perception of earthquakes, the risks, how they juxtapose different dimensions of reflections on the world, on religion; like voodoo, in close contact with nature and in particular with its perception of earthquakes, comes into play in all this … We are interested in all these questions.