The "Big One" on the San Andreas fault just got a little bigger.

New research showing a section of the fault is long overdue for a major earthquake has some scientists saying that the fault is capable of a magnitude 8.1 earthquake that could run 340 miles from Monterey County to the Salton Sea.

Whether such a quake would happen in our lifetime had been a subject of hot debate among scientists. That's because experts had believed that a major section of the southern San Andreas, which runs through the Carrizo Plain 100 miles northwest of Los Angeles, would remain dormant for at least another century.

But that rosy hypothesis seemed to be shattered by a recent report in the journal Geology, which said that even that section of the San Andreas is far overdue for the "Big One." [Updated, Oct. 9: The report, published in August, was written by Sinan Akciz and Lisa Grant Ludwig of UC Irvine, and J. Ramon Arrowsmith and Olaf Zielke of Arizona State University.]

Now, according to U.S. Geological Survey seismologist Lucy Jones, it is entirely possible that all 340 miles of the southern San Andreas could be ready to erupt at any time. Such a scenario would trigger a magnitude 8.1 earthquake, said Thomas Jordan, director of the Southern California Earthquake Center, a calculation with which Jones agreed.

"All of it has plenty enough stress for it to be ready to go," Jones said. "The biggest implication of [the report] is that it increases the likelihood that when we do have a big earthquake, it will grow into the 'wall-to-wall' rupture."

[Updated, Oct. 9: Such a temblor could cause much more damage because with a longer stretch of the fault rupturing, a larger area is exposed to the quake, and the shaking would last longer.]