Over the past 500 years, four large earthquakes have occurred near the same location along a continental-continental transform fault in North America. After scientists observed a nearby stream that crossed the fault, they concluded that the earthquakes had offset the stream by 60 yards from its original course. Thus, on average, each earthquake caused the crust along the fault to slip about 12 yards. The earthquakes caused a lot of damage, as well as dramatic changes to the local ecosystem.
Another area in the fault also experienced a shift in location of 60 yards over 2,000 years. But it did so without suffering a violent earthquake. In this area, the crust along the fault slipped about an inch every year. The slip caused several rock formations and structures to develop cracks. However there was no large-scale disaster or disruption.
Which two conclusions can be drawn based on this information?
Earthquakes do not strike the same region more than once in any given century.
Geological movements are often hazardous when they happen quickly.
Earthquakes happen only on continental transform boundaries.
Transform boundaries experience fewer earthquakes than other boundaries.
The movement of plate boundaries does not always cause disasters.