In Canada we know what a 2-4 is. It's a case of beer to watch the hockey game! Good times.
Not so good down there.
These 4's aren't even a penultimate quenching event, they are part of the chatter. At some point we can have a runaway reaction, but this probably isn't it.
A chatter that includes 4's means that something bigger is coming. I sure wish they would have sprung for some accelerometers. Those puny seismometers are just going to bounce out of their cases.
Anyway these events seem to be deep, so nobody should be worried.
Update: both events are oblique-normal (tension), so not much of a PGV (Intensity).
Update2: Intense chatter close to 4. Wouldn't want to be around there.
Update3: Difficult to know the exact physics here. If I were a young spring chicken with a big computer, I would model it as discrete elements. Then I would figure out what is the more likely mechanism - that of a large event starting to give a difficult birth and stimulating the storm, or the inverse of the storm giving rise to a big bouncing baby...