Why do major earthquakes keep happening in Lombok recently?

Question

So I've been following the situation in Lombok, Indonesia from both online news and friends on the ground. One thing that I can't seem to figure out is why there are so many earthquakes over an extended period of time?

Is it common for there to be earthquakes for a whole month and of high magnitudes too in seismic zones?

I have read that there can be aftershocks but I don't think that all these quakes can be characterized as aftershocks of the initial quake? These quakes seem to be independent quakes and not a continuation of aftershocks.

The major 3 have also been progressing from the south to the northwest to the northeast of the island as though it is following some pattern. So is this a sign that an underlying seismic development such as a major shift in tectonic plates or a new volcano formation will take place?

Please explain it to me like I'm 5.

Answer 1

Yes, it is quite possible to have a number of earthquakes over an extended period of time.

The phenomenon is actually quite common. Some famous sequences are: New Madrid in 1811-1812, Eastern California Shear Zone (1992-1999), Italy (2009-2016), New Zealand (2010-2011) etc. These are all areas where rates of seismicity are relatively low so a number of events in quick succession (as you saw in Lombok) is not due to pure chance.

The idea of one earthquake triggering another on a neighboring or nearby faults is not new.