Mystery vibrations solved by first year students

I didn't want to start on this note, but alas, I just saw this on LiveScience.com:

http://www.livescience.com/forcesofnature/060413_earth_tremors.html


The first paragraph should suffice to send any geologists out there into a catacleptic fit:
"Tremors deep inside the Earth are usually produced by magma flowing beneath volcanoes, but a new study suggests they can also be produced by the shifting and sliding of tectonic plates."

I'm sorry, but this calls for it: What were they thinking? A revision of Geology 101 is definitely required here.

So firstly, of course magma motions cause minor earthquakes (note:minor). These are generally shallow level and directly under volcanoes.
But nearly the first thing taught in undergraduate geology is plate tectonics, the basic premise being that the Earth is made up of plate which move around, and where they rub (at the plate boundaries) is where you get Earthquakes.
Check out the map of global earthquakes at the US Geological Survey:

http://wwwneic.cr.usgs.gov/neis/weekly/weekly.gif

People have known for the last 50 years that the reason you get massive Earthquakes around the Pacific is primarily because of plates being jammed under one another as they subduct back into the mantle (think of the Mariana's Trench near Japan). The biggest Earthquakes ever, in Alaska & Chile, are associated with plate boundary motions. There are literally thousands of examples of Earthquakes occuring around plate boundaries near no known volcanoes. In fact, earthquakes as deep as 700km have been recording, which occur due to the motion of a downgoing plate.

I have no idea where they've got this "volcanoes cause all earthquakes" rubbish. All they had to do was pick up an introductory geology text. Makes me worry bout some of the science reporting going on out there.