These are not the type of fault lines that cause massive earthquakes, but they can and do cause damage from slow earth movement, approximately an inch a year. According to Science Daily’s online article, “On Shaky Ground: Geological Faults Threaten Houston” published on April 29, 2008, geologists at the University of Houston have mapped multiple fault lines using radar-like laser technology to produce a highly detailed map which identifies over 300 faults.
Even though the earth doesn’t shake with the slow movement of these fault lines, they are significant for the displacement they cause, which can result in damage to buildings, roads, and underground pipelines. Be sure to read the article online. It isn’t long. It isn’t highly technical, but it is very interesting, especially if you live in this area.