The two earthquakes that hit Venezuela, with magnitudes 7.2 and 7.5, were triggered by the relative movement between the Caribbean plate, to the north, and the South American plate, to the south, which activated a complex system of faults. The two tremors occurred just 39 seconds and 13 kilometers apart, in a dynamic reminiscent of the violent tremors of 2023 between Syria and Türkiye. What made the effects devastating was the strong shaking due to the reduced depth, just 3 kilometres.
Close, shallow shocks – the most dangerous combination
«The two very important tremors occurred close together and at a very shallow depth, a combination that can easily cause a major impact on buildings and infrastructures», explains Salvatore Stramondo, director of the Earthquake Department of the National Institute of Geophysics and Volcanology (Ingv). The characteristics of the event, he observes, are reminiscent of “what happened in Syria and Turkey between 5 and 6 February 2023, with two violent earthquakes of magnitude 8.0 and 7.5 a few hours apart”.
A “not rich” seismic network: data must be integrated
Regarding the numbers, the expert urges caution: «In this case we had 39 seconds and 13 kilometers of distance, but we also know that there is a certain margin of error due to the local network not being particularly rich in detection stations». Precisely for this reason, the data collected so far will be combined with that of other stations, so as to reconstruct in detail the characteristics of the faults and the dynamics of the event, which occurred “in a complex region at the margin between two plates that have a strike-slip movement, i.e. a horizontal sliding with each other”.
An area already affected in the past
Similar events are nothing new for Venezuela, which has experienced other strong earthquakes in the past, such as the 7.7 magnitude one that hit Caracas on October 29, 1900.
No link to the earthquake in Japan
Finally, Stramondo excludes any connection between the Venezuelan double shock and the 7.0 magnitude earthquake recorded 25 minutes later in Japan, east of Honshu: «They are completely different events, which have no connection. We tend to notice connections, perhaps letting ourselves be guided by timing. But it is a mistake: the two phenomena are absolutely independent.”