Slo1 - Plate Tetonics

San Andreas Fault:

On July 4, 2019 Ridgecrest California was hit with a 6.4 magnitude earthquake and then at 7.1 the day after. I remember when the 7.1 earthquake happened me and my family were moving furniture in my old house because we were planning to move. All of a sudden I remember the ground just moving like a wave. Something so scary that I never had witnessed before. But neither of these earthquakes compare to the long awaited big one. “The big one” is the term for a high magnitude Earthquake predicted to strike on the San Andreas Fault in California and surrounding states. California is located in a hot zone of fault lines. The main of the faultlines being the San Andreas Fault ruptures every 150 years. The southern part of the fault line has been inactive for over 200 years scientist believe we are very long overdue for a big earthquake. In 2008 there was a federal report that the most likely scenario magnitude of an earthquake is about 8.0. That would rupture a 200 mile stretch along the southern most part of the fault. Starting around the Salton sea through Palm Springs, San Bernardino country, Los Angeles County, and then possibly into central and Northern California. The fault was identified in 1894 by Professor Andrew Lawson of UC Berkeley, who discovered the northern zone. It is often described as having been named after San Andreas Lake, which is formed between the two plates. Following the 1906 San Francisco earthquake, Professor Lawson found out that the fault extended all the way into Southern California. From 2004 through 2007 a project started called the San Andreas Fault Observatory near Parkfield California, which involved drilling through the fault to collect material and make physical and chemical observations to better understand fault behavior. Seismologists discovered near the Central Valley, the fault produces a magnitude 6.0 earthquake about every 22 years. Due to the frequent predictions in activity, the Earthquake center has become one of the most important areas in the world for large earthquake research.

How the climate effects the plate tectonics..

According to the US Geological Survey, for many years there’s been “rumors” about how there is earthquake weather when it gets very warm or hot. But research has been shown that the only correlation that’s been found between earthquakes and weather is that large changes in atmospheric pressure caused by major storms like hurricanes and thunderstorms has shown a history of triggers what are known as slow earthquakes . Which releases energy over long periods of time. It notes that while such large low pressure changes could potentially be contributing a trigger to damaging earthquakes. So now we know water and storms can affect earthquakes. What about dry weather? Such as droughts… as it turns out changes in stress loads on earths crust from droughts can in fact be significant. GPS stations in California found that alternating periods of drought and heavy precipitation in the Sierra Nevada between 2011 and 2017 caused the mountain range to rise by nearly an inch and then fall by half that amount. Well the study didn’t specifically look at potential impact on faults, but such stress changes could potentially be felt on faults in or near the range. Similarly, pumping of groundwater from underground aquifers by humans, which is exacerbated during times of drought, has also been shown to impact patterns of stress loads by “unweighting” Earth’s crust. Paul Lundgren of NASA pointed to a 2014 study that looked at the effects of groundwater extraction in California’s Central Valley on seismicity on the adjacent San Andreas Fault. The research found that such extractions can promote lateral changes in stress or the two sides of the San Andreas fault. This could potentially cause them to unclamp and slip resulting in an earthquake.