Only a few of the world's earthquake faults contain these
freeway sections, but there is one major fault that Das is
concerned about. "The Kunlushan Fault in Tibet is very similar
to the San Andreas Fault in California," Das said. Both faults
move horizontally rather than vertically, and both faults
contain long straight sections. Das and her colleagues believe
that a superfast rupture may have been partially responsible for
the extreme devastation caused by California's 1906 earthquake.
"The long straight bit goes directly underneath San Francisco,"
Das said. (See a photo gallery of San Francisco after the 1906
quake and now.) Engineering a Fix So can this information help
the people of San Francisco prepare for the next big one? "There
is quite a lot that can be done in terms of building design to
ensure they can cope with the higher frequencies of a faster
wave," said Ian Main, a seismologist at Edinburgh University,
who wasn't involved in Das's work. "New buildings can be built
on rollers and sited on bed