Yesterday a violent earthquake of magnitude 7.3 struck Alaskaa few tens of kilometers from the coasts. It was a relatively superficial shock, with a hypocenter located at about 21 km deep. This earthquake was not the only one in the area: in the following hours there was a seismic sequence of about 40 shocks with magnitude between 2.0 And 5.0. Fortunately, this happened in a remote area of Alaska and therefore at the moment they are not reported nor injuries or damage to infrastructure. It is also good to report how an at first had been issued an ‘Tsunami alerteven if withdrawn a few hours later.
As for the magnitude of the earthquake, not at the moment not all values are concordant. THE’United States Geological Service reported one magnitude of 7.3while theNational Institute of Geophysics and Volcanology instead reports a 7.0. These are minimal differences due to uncertainties in the measurement and probably in the next few hours the data will tend to converge.
From a geological point of view, a earthquake of this type in Alaska should not be surprised. This area, as clearly visible from the underlying image provided by the USGS, is located close to the area of subduction from the peaceful plaque below that North American. As we can see in fact along this margin there are many dots that represent the historical seismes that occurred in the area: those with a darker color indicate deeper editions, while the larger ones represent the strongest. If we look at the top right in the image, we also see the Second strongest earthquake in history who, in 1964, recorded an incredible magnitude of 9.2.
