NAPA (KCBS) — Wednesday marks the second anniversary of the big quake that struck Napa, and seismologists with the USGS say the valley is poised to have more, and possibly stronger quakes.

The Yountville earthquake that struck in 2000 was a magnitude 5.0, and the South Napa quake was a 6.0. Both were tied to the West Napa Fault.

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USGS Seismologist Jack Boatwright says the Concord-Green Valley Fault could pose even more problems.

“That has not had a rupture on it since historical times in Northern California, since 1776 or so,” Boatwright said.

Boatwright said the West Napa Fault has the potential to unleash another major quake on the area.

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“There’s enough un-faulted sections of the West Napa to host a magnitude 6.0,” he said.

Boatwright says the Rodgers Fault is also capable of producing a strong quake.

All three of those faults are located in a relatively small area.

More than 4,600 aftershocks have shaken the region since the the 6.0 magnitude quake struck on August 24th, 2014. One person was killed, and 200 others were hurt in that earthquake.

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