Only one marsquake was recorded and it isn't known how frequently they occur. Earthquake waves are created when the two sides of a fault rapidly grind past each other. The faults can be anywhere from metres to thousands of kilometres long. The mechanism that causes the deepest earthquakes isn't well understood. At 600 km the earth is probably too warm for faults to be brittle like glass, so some sort of chemical change might occur very rapidly.
Faults can be as short as metres and as long as a thousand kilometers.
The earthquake was centred 640 km beneath Bolivia and had a magnitude of 8.3 and was felt in tall buildings as far away as Seattle Washington. The earthquake was felt at such a large distance because seismic waves aren't damped out nearly as fast from earthquakes deep in the earth as they are from near-surface earthquakes. E-mail us here.