4.4 Earthquake: Just another day in L A

A 4.4 magnitude earthquake occurred this morning in Los Angeles at 4:04 AM.  No serious damage or injury has been reported.  For L A residents, this is relatively minor event.

I do want to comment on a couple things, though:

First, how quickly most of the regular locals jumped on Twitter and FaceBook to begin talking about the quake.  And the quality of the information reported.

@HLP90042 and @militantangelino had the magnitude and epicenter maps posted on Twitter before KNX Radio.

And secondly, this came up in my conversation with @HLP90042, and I am intriqued enough to research further.

My 90-something year old house has a two story tall arroyo stone chimney.  That chimney has survived numerous earthquakes without a scratch.  (Knocking on wood as I type that!!)

@HLP90042 commented that stone chimneys seem to withstand quakes around here better than their brick counterparts.

Yeah, that fits with the empirical evidence.

So, why is that?  I am not an engineer, but my theory is that because the stones are different sizes and irregular shapes, the load/weight of the chimney is distributed in a random manner ... and the resultant object is sturdier than an object built of completely uniform components.

Any engineers here?  Am I on the right track?