Like a steaming kettle with the top on, pressure is building beneath the surface of California that could unleash a monster earthquake at any time. That's according to a new study from the Scripps Institute of Oceanography. 

Geologists say Southern California is long overdue for a huge earthquake that could unleash widespread damage. 

It all comes down to the Salton Sea, which lies to the east of San Diego. The Salton Sea lies directly on the San Andreas Fault and covers more than 350 square miles. 

A big earthquake has hit the lake bed about every 180 years. But when officials started damming the Colorado River to reduce floods downstream (including in the Salton Sea), the moderate earthquakes stopped for the Salton. 

Sounds like a good thing, right? Not necessarily. Seismologists think the damming stopped moderate stress-relieving earthquakes on the Salton. Now, they fear the pressure is building and the area could be as many as 100 years overdue for a mega-quake quake, measuring 7.5 or larger. 

This sobering news comes just as a new poll is released that details Californians fears about earthquakes and other natural disasters. 

Natural Disaster Californians Fear Most 

Earthquake 57% 
Wildfire 23% 
Tsunami/Tidal Wave 9% 
Flood/Mudslide 5% 
Other/No Opinion 6% 

The findings were published in the scientific journal "Nature Geoscience."