HQ – The faulting in the crust of the Caribbean plate was the origin of a strong earthquake that shook the Greater Metropolitan Area (GAM) Tuesday afternoon, minutes before 6:00 pm.
This according to the National Seismological Network (RSN), which specified that the magnitude of the quake was 4.6 degrees.
The institution located the epicenter of the earthquake one kilometer east of San Miguel de Desamparados, San José, and indicated that the depth was only nine kilometers. This situation, therefore, affected how the event was perceived.
“The earthquake originated in the Río Azul fault system, which runs between Desamparados and Tres Ríos,” said Ivonne Arroyo, a seismologist for the RSN.
For their part, the Volcanological and Seismological Observatory of Costa Rica (Ovsicori), reported the same magnitude as the RSN; however, it registered a depth of eight kilometers and located the epicenter five kilometers southeast of Desamparados.
The entity specified that the origin of the tremor was registered at 5:57 pm.
Some people reported falling objects in their homes, while others said they heard a rumble seconds before the earthquake.
Others just recall a big bang, to the level never experienced before.
At the Q, in Santa Ana, some distance from the epicenter, it was a jolt and then a mild shaking for several seconds.
The RSN website states that “this usually happens when earthquakes are shallow and occur close to the observer. In these cases, the first seismic waves to reach the surface are P-type (primary) waves, which are followed by S waves (secondary) and surface waves. The latter are the ones that are usually perceived more clearly”.
The experts emphasize that “part of the noise can come from the sudden movement from top to bottom generated by the P wave in the objects inside the buildings”.
At least 10 replicas were recorded Tuesday evening, the strongest registering 2.7.