mainshock

During the mainshock the sand was said to have formed waves.

The mainshock could be felt as far away as Switzerland.

A series of tremors were reported during the week leading up to the mainshock.

The mainshock was followed by aftershocks that continued for more than a month.

The mainshock was preceded by a series of small foreshocks.

A strong foreshock preceded the mainshock by about 20 to 25 seconds.

The earthquake was preceded by foreshocks in the few days before the mainshock.

Most of the time, the worst aftershocks occur within the first 24 hours after the mainshock hits.

The 7.1 mainshock was preceded by a 6.6 magnitude foreshock some 48 minutes previous.

The mainshock was preceded by a magnitude 5.1 foreshock ten hours earlier.

The sequence continued until 4 p.m. on April 2, when the mainshock occurred.

At Campo 155 aftershocks were felt in the first 12 hours after the mainshock and continued every few days for the next two months.

From such combined observations, the increase before the mainshock is observed to be of inverse power law type.

Given the rarity of such large events in this area it has been considered more likely that the reports all refer to the same mainshock.

Between 12:00 and 13:00 in the afternoon, Bucharest was hit by the mainshock.

Despite the difficulty of separating the effects of this event from the mainshock, some information is available.

However, there is a small chance, approximately 5-10%, of an earthquake equal to or larger than this mainshock in the next 7 days."

The designation of an earthquake as foreshock, mainshock or aftershock is only possible after the event.

It is unclear as to whether they refer to a single mainshock with several large aftershocks or more than one unrelated earthquake.

The estimated magnitude for the mainshock is 7.1 on the surface wave magnitude scale.

In the three hours following Taiwan's mainshock, for example, there were only seven quakes that would have done more than lightly rattle dishes.

An aftershock is an earthquake that occurs after a previous earthquake, the mainshock.

Additionally a 5.3 aftershock hit the region very near the mainshock epicenter on April 8 at approximately 9:44 am local time.

The mainshock was followed immediately by an aftershock, the first of a series that lasted until June of the following year.

This aftershock would be considered a major earthquake under ordinary circumstances, but is dwarfed by the mainshock.