Possible Earth-like activity on Mars

The latest findings, made by comparing photos taken by a camera aboard NASA's Mars Global Surveyor spacecraft, were announced yesterday.

Placing photographs side by side, researchers at the company discovered mysterious gullies appearing on the walls of sand dunes in less than three years, tracks from boulders that had tumbled down the steep wall of a crater between November 2003 and December 2004, dramatic melting of ice at the south pole over three consecutive martian summers, and even a meteorite crater that hadn't existed 20 years ago.

The boulder tracks have particularly interested scientists. Exactly what may have shaken the boulders loose is unclear. Strong winds could have dislodged them, but researchers yesterday said they couldn't rule out a "marsquake."

www.signonsandiego.com...

I thought Mars didn't and couldn't have "Marquakes" since the whole planet is pretty much solid and without water? Not to mention it doesn't generate an EM shield, doesn't that mean the core is dead?

I might be wrong in what i think i know, thoughts and opinions anyone?
(And let me know if I am wrong please )

Mars is, as far as I understand, tectonically dead, meaning that its crust is not seperated into plates that are in movement. Lots of earthquakes are caused by the motions of these plates (more or less). However, there are other ways to get faults and cause earthquakes, it doesn't strictly require a tectonically active planet.

Tho these boulders might've dropped simply due to regular old gravity no?