PR Release About LA Earthquakes

Earthquake Press Release

This announcement serves as a general information bulletin for those that are curious or need to learn about earthquakes and the associated hazards whilst living in the Los Angeles area. Indeed, the city of Los Angeles as well as much of the rest of the state of California sits along what is known as the San Andreas Fault. The fault is a point in which two major tectonic plates of the Earth's crust are moving in opposite directions from each other and the friction and pressure caused by these movements sometimes causes earthquakes throughout California. Effects and results from earthquakes would include ground displacement, flooding, and fires. The floods are caused by damages to water infrastructure and dams, just to name a few things. Fires can be caused by ruptured gas lines and such being ignited by an ignition source (MTU, 2015).

The ferocity and "magnitude" of earthquakes, as described in a brief second, are measured on a scale that is known as the Richter scale. The scale has ten points but it should be noted that the scale is not proportional from number to number. Indeed, a four point earthquake is not twice as bad as a two point earthquake. Instead, the scale is what we call "logarithmic" and thus a four point earthquake would be much more severe than a two point earthquake. Earthquakes below five are fairly minor and can do some minor to mild damage. Earthquakes at or above five on the Richter scale can do some major damage. Anything approaching seven or eight (or above) can be catastrophic. Further, earthquakes that occur in or around oceans can cause tsunamis (MTU, 2015).

Significant earthquakes in the Los Angeles area actually date back to 1769 before the area was really settled. More recent earthquakes happened in December 1972, September 1827, July 1855, January 1857 and a few others in the 1800's. Ones that have happened since are the Lake Eisnore quake in 1910, the Tejon Pass earthquake in 1916, the San Bernadino quake in 1923 and a few others in the time of the Great Depression. There were a few earthquakes in the early 1990's with the worst of the bunch being the famed Northridge earthquake in 1994. Since then, there have only been a few minor ones. There was a mild one in the Chino Hills area in 2008 and another mild one in March 2014 in the greater La Habra area. The Chino Hills earthquake was a magnitude 5.4 earthquake while the La Habra one was about a 5.1 with aftershocks in the 2.1 to 3.6 Richter range (Foreshock, 2015).

While major earthquakes in the Los Angeles area have been sparse as of late, at least since the 1990's, this could literally change at any time. Indeed, the United States Geological Survey (USGS) says that the overall risk of a 8.0 earthquake in California is on the rise. However, the overall odds of such an earthquake are still rather small. Indeed, the USGS says the overall chances have only risen from 4.7% to 7%. Further, the frequency of such earthquakes is once every 494 years to once every 617 years. Something that should be considered is that when some earthquakes happen, there are ruptures between faults in multiple places. Further, some quakes that have been quite close to 8.0 have happened in fairly short succession. For example, there was a 7.3 earthquake in the Landers area and a 7.2 in the Hector Mine area and both of those are in the Mojave desert area (Lin & Xia, 2015).