Earthquakes: Are they related to our weather?

California could be hit with a major earthquake generated from a “double-fault,” a recent report suggests. A geophysicist from California State University theorizes that a joint rupture of the San Jacinto Fault and the infamous San Andreas Fault in Southern California could cause a catastrophic earthquake in the near future.

The research says this scenario did happen in December 1812. An estimated 7.5 earthquake started along the smaller San Jacinto Fault. Its energy moved to the nearby San Andreas Fault, causing it to rupture as well.

The Golden State experiences earthquakes on a daily basis, but many are so small that very few people feel them. There are hundreds of faults and most agree that the most infamous, the San Andreas Fault, is overdue to trigger a strong earthquake. The prediction is for a large earthquake to hit along the fault within 30 years. Others say it should be much sooner.

According to the earthquake experts at the United States Geological Survey, there are three main reasons we see more news about deadly quakes. The first is that the quality of reporting is much higher in recent years. Second, there are now more digital seismic networks around the globe for better reporting and also receiving data in real time. The last reason is that more people live in quake-prone areas now compared to several decades ago.

Here in Idaho, on April 23, 2015, a series of small earthquakes shook the Sandpoint area and were also felt in Coeur d’Alene and other areas. The following morning, April 24, a 6.1 quake was reported off the coast of British Columbia. It seemed to be very seismically active for the Northwest around that time. Last Friday, March 18, a 2.7 magnitude quake was reported at Entiat in central Washington.

The fault system across the Inland Northwest does not compare to the Cascadia subduction zone that stretches for more than 600 miles from British Columbia to northern California. This area has a history of very large earthquakes and scientists say that a devastating event could hit along the West Coast sometime in the not so distant future. However, thanks to the Cascades, the Inland Northwest would not likely feel the full impact of that disaster. I’ll have more details on this phenomenon next week.

The strongest U.S. earthquake ever recorded happened on Good Friday, March 28, 1964, at Prince William Sound in Alaska. It had a magnitude of 9.2 and devastated the city of Anchorage and also generated a massive tsunami. The quake was so strong that it was felt as far away as Florida.

By the way, like California, Alaska is also very active in terms of earthquakes. They’ve reported nearly 2,500 in the last year, with the largest being a 7.1 magnitude at Anchor Point.

The largest recorded quake in the world happened in Chile on May 22, 1965. The epicenter was offshore and measured 9.5. Chile had another big quake that measured 8.8 on February 27, 2010.

In our region, the largest quake occurred in 1942 and was centered 35 miles northeast of Spokane. It measured a 5.5 on the Richter Scale. In 2001, Spokane was in the throes of an “earthquake swarm.” Nearly 100 earthquakes were recorded over a six-month period with a 3.7 magnitude reported on June 25, 2001. Scientists are still uncertain why our region experienced this swarm of quakes.

Many people have wondered if there is a connection between the weather and earthquakes. Geologists maintain that there is no relationship as seismic activity is the result of geologic processes within the Earth and can happen in any weather and any time during the year.

However, some scientists and others wondered why approximately 65 percent of the most notable earthquakes nationwide were occurring in the spring and fall seasons and only about 35 percent in the winter and summer periods. In other words, are there “earthquake seasons,” much like hurricane, snow and tornado seasons? Maybe yes, maybe no.

In terms of our weather, as of early Sunday, 3.09 inches of rain and even a little snow had fallen in Coeur d’Alene in March. We’re already getting close to 10 inches of moisture for the 2016 season. This “full moon” cycle beginning on March 23 should bring us more rain in the lower elevations. There is also the possibility of a little snow, but mainly over the mountains.

For Easter Sunday, there is a chance of a few rain or snow showers, but mainly over the mountains. Temperatures are expected to be on the chilly side, especially early Sunday morning.

As we get into April and May, we should start to see more days with sunshine and less moisture. But, we should see occasional showers and thunderstorms, as is typical during our spring season.

If you have any questions, please email me: randy@longrangeweather.com.