The threat of an earthquake occurring during a pandemic is very real, and can pose a problematic management of COVID-19 cases and health emergencies. The occurrence of earthquakes coincident with the pandemic may prevent the effective practice of mitigating measures such as social distancing, that can consequently cause an increase in the virus spread.
Objectives of the study
To better understand the link between COVID-19 and earthquakes, Vitor Silva and Nicole Paul conducted a study on the "Potential Impact of Earthquakes during the 2020 COVID-19 Pandemic". The paper discusses the potential for earthquakes to trigger or exacerbate infectious diseases, and models the additional mortality to COVID-19 that would be expected from earthquake scenarios in Portugal for various levels of infection. The methodology can easily be generalized to any earthquake/covid scenario and to a fully probabilistic analysis.
Regions of high seismic and covid-19 combined risk
To identify regions of high seismic and covid-19 combined risk, the study used recent data on the number of confirmed cases at the national or subnational level combined with a global seismic hazard and risk map to produce a combined index. This index highlights regions where preparedness and contingency plans should be developed to account for the possibility of COVID-19 outbreaks due to the earthquake impact. View the maps: hazard-covid and risk-covid.
Results of subnational simulation
Using Portugal as an example, the authors simulated the potential impacts of two scenario earthquakes near Lisbon that are typically used by government officials for contingency planning: A) a magnitude 5.7 earthquake located onshore beneath Lisbon; and B) a magnitude 8.7 earthquake located offshore, representing a repeat of the Great Lisbon Earthquake of 1755. For these two events, they estimated the population displaced from severely damaged and collapsed buildings. The increase in infection rate was then calculated from the inability to maintain social distance and other safeguards for displaced people who are placed in alternative shelters.
- Case A represents a relatively optimistic scenario in which the transmissibility slightly increases after the seismic event, and then decreases accordingly as counter measures are put in place in line with existing response capacity; and
- Case B represents a pessimistic scenario where the transmissibility would increase sharply after the seismic event as existing response capacity is exceeded.
Accordingly, the results demonstrate a wide range in the potential for increased infection and mortality depending on the physical earthquake impact and the resulting displacement of population. According to the study, this indicates that stricter and more effective measures would have to be rapidly implemented in order to counter the spread of the infection.
Impact of the study on future DRR strategies
The study should be useful to national and local governments to prepare contingency plans for dealing with future risks that combine the impact of earthquakes, pandemics and other disasters that endanger human lives and displace people from their homes.
This study is in press in Earthquake Spectra and will be released in the coming weeks.