#Ver san andreas quake 2015 online series

How would San Diego likely be affected by a major earthquake in the Southern San Andreas if/when it occurs?

#Ver san andreas quake 2015 online series

Hill: However, we can not determine for certain if all of the accumulated stress will be released at once in a large event ( worst-case scenario) or if the stress will be released by a series of a few smaller earthquakes (best-case scenario). The Northern San Andreas hosted the Great 1906 San Francisco Earthquake with an estimated magnitude of M7.9.

Geological Survey estimates the Southern San Andreas has a roughly three times greater chance than the Northern San Andreas of hosting a magnitude M7.5+ earthquake in the next 30 years (17.3% vs. That theory holds true for the Southern San Andreas, which poses the highest seismic hazard in the state. We know from earthquake physics that the longer you go without relieving the stress built up on a fault, the more likely you are to have a major earthquake. Plate tectonics is operating on faults all over the world every day.

So we're still overdue for the 'Big One'? If all that stress is released at once the fault has the current potential for a major (magnitude 7.0+) earthquake. Regardless of any of the minor clamping effects the drying up of the last lake has had, the accumulation of stress from the tectonic plate motion has built up considerably over the past 300 years and will need to be released. We have direct geodetic measurements on this section of the San Andreas Fault. However, this does not fully explain why we have not had a major earthquake during this time. Hill: The drying of the last lake contributes, in small part, to clamping the fault.

Los Angeles to the northwest has experienced plenty of destructive earthquakes originating in the Southern San Andreas Fault since then, but none of these has topped magnitude 7.0 on the Richter scale. The Salton Sea has experienced a relatively dry period since the 1730s-300 years ago. The increasing pore pressure from the fluid is like turning the air on-it pushes out on the two sides of the fault making it easier to slide, thus triggering an earthquake. A puck on an air hockey table is a good analogy. This causes an increase in pore pressure which also makes it easier for the fault to slip. This is like taking a ruler and bending it in the middle, unclamping the two sides of the fault and causing it to slip.Īnother effect is the fluid of the lake itself. When the lake would fill, it was large enough to bend the upper crust of the Earth. The lake filled and dried up periodically over the past 1,000 years. Hill: Ancient Lake Cahuilla held approximately 40 times the volume of water as today's Salton Sea, with an area six times the size. Your study found that over the past thousand years major earthquakes took place every time water levels in the lake reached a high point, about every 180 years. The Salton Sea, which is a remnant of the much larger ancient Lake Cahuilla, has gone through many cycles of drying out and filling up again due to fluctuations in the climate. SDSU NewsCenter's Susanne Clara Bard asked geophysicist graduate student Ryley Hill and his advisor and co-author Matthew Weingarten about what this means for future earthquakes in the region. Now, a new study in the journal Nature by scientists at San Diego State University in collaboration with UC San Diego's Scripps Institution of Oceanography has found that as the Salton Sea has dried up, it has eased the strain on this part of the fault, potentially postponing a quake that could devastate Los Angeles.