¡Alerta! Engineering on Shaky Ground by Elizabeth Reddy (review)

Reviewed by: ¡Alerta! Engineering on Shaky Ground by Elizabeth Reddy Magdalena Gil (bio) ¡Alerta! Engineering on Shaky Ground By Elizabeth Reddy. Cambridge, MA: MIT Press, 2023. Pp. 226. ¡Alerta! is a well-researched and engaging book that provides valuable insights into the socio-technical challenges of using technology to mitigate the impact of extreme natural events such as earthquakes. The book defies the traditional view on technological development that concedes little or no agency to peripheric countries, who appear as mere recipients of modern "Western" science. In contrast, it focuses on the Sistema de Alerta Sísmica Mexicano (SASMEX), the world's oldest earthquake early warning system. SASMEX was created in 1989, and it is still active today. It works by issuing a warning within seconds of an earthquake. The warnings are sent to a variety of public and private entities, and also broadcast through the media and over loudspeakers in public places in Mexico City. It is based on the Time-to-Arrival (TTA) method, which uses the difference in arrival times of seismic waves at different locations to estimate the location and magnitude of an earthquake. But SASMEX is much more than that. Reddy tells us that the system also depends on a number of factors, including the political will to support the system, the public's understanding of it, the availability of resources to implement and maintain it, the perceived legitimacy of the alerts, and the willingness of people to comply with it. In other words, the book shows us that the system is part of a broader socio-technical ensemble that includes other technologies, people, and the Earth. Reddy explores the history, development, and implementation of SASMEX from 1989 to present-day Mexico, using varied archival sources from local newspapers to scientific works from the Union Geofisica Mexicana. But the core of the book is her extensive ethnographic work in Mexico, observing and documenting the practices of communities living in risk zones, and also the scientists, engineers, and government officials who organize and enact SASMEX daily. While exploring the history of SASMEX, Reddy focuses on the issue of environmental monitoring and how it has increasingly become a techno-scientific endeavor, heavily based on data analysis. Through her case study, she explores the challenges and opportunities of this approach, arguing that this technology not only mitigates the potentially huge damage that earthquakes can have in physical structures but also social inequalities. The system is especially relevant for people in low-income communities, who are often the most affected. This is the value of the models, and the reason why the Mexican state has invested in a system to support it. End Page 688 But SASMEX can also give false alarms. Since the TTA method is based mostly on probability research, false alarms are the product of the system's failure but also an expected outcome. The number of false alarms issued in a year depends on a number of factors, but it can reach up to one hundred. Also, sometimes an earthquake will occur, but it will not be so strong as to need an alarm. These events diminish the trust that Mexicans have in the system and lead to discussions about the risks and benefits of earthquake early warning technology among engineers, scientists, and policymakers involved in the project, and also with the public. Through expansive ethnographic fieldwork, Reddy helps us understand the different challenges, shedding light on the limitations of the modern dream of controlling nature with calculations. While there are other earthquake warning systems, such as ShakeAlert in the United States and EEW in Japan, the Mexican system offers a particularly interesting subject of analysis due to the particular challenges that engineers and scientists have in running the system in a country with a relatively high vulnerability of infrastructure, the precarious political situation in some particular areas, and the fact that Mexico City is far away from any seismic fault but can be heavily damaged by earthquakes that come from the coast, due to its swampy ground. It makes one wonder if SASMEX has been implemented to compensate for the lack of building resilience and state capacities in other areas. Overall, ¡Alerta! is a...