Powerful earthquakes in California came after changes in magnetic field, study shows

Researchers who have studied moderate to large sized strong earthquakes in California have found that the local magnetic field changes 2-3 days before an earthquake.

Seismologists hope their method can be improved so that it can eventually be used to predict earthquakes after a study by William Heavlin and his team discovered that the magnetic field change in the signal is weak but statistically significant.

Dan Schneider, the director of QuakeFinder, said a modest signal was discovered. He said that while they don’t claim that this signal always precedes earthquakes, it’s still very intriguing.

A systems engineering services company called Stellar Solutions has an earthquake research division called QuakeFinder. Schneider is co-author of the recently published study.

The long-controversial concept

Although it has been debated for some time, the idea that the magnetic field might change before strong earthquakes has existed for some time. According to the US Geological Survey, despite decades of research, there is still no conclusive evidence that there are electromagnetic precursors to earthquakes.

Researchers, in collaboration with the Google Accelerated Science team, accessed magnetic field data from a collection of magnetometers at 125 sensor stations along major faults in California. They collected information between 2005 and 2019, a period in which 19 earthquakes measuring 4.5 magnitude or greater struck the fault.

Their multistation analysis considered other types of processes, such as B. rush hour traffic, which could affect the magnetometers, but have nothing to do with earthquakes. According to Schneider, the biggest challenge in interpreting this data is distinguishing this type of noise from possible earthquake-related signals. The researchers discovered a signal showing magnetic field changes from 72 to 24 hours before the earthquakes after training their algorithms on 50% of the dataset.

In the future, says Schneider, he wants to refine the models even more to account for more background noise from the magnetometers. In this study, for example, taking into account the typical influence of solar activity improved the results significantly. The team will use data from distant stations to continue their work and further eliminate noise from solar activity.

According to Schneider, the research suggests that there may be predictable fluctuations in the magnetic field that, with more study and isolation, could one day aid in the development of a prediction system, Phys Org reports.

Also Read: 7.1 Magnitude Earthquake in California Leaves Large Cracks in Ground Seen From Space

earthquake

When two blocks of earth move abruptly past each other, an earthquake occurs. The fault or fault plane is the area where they slide. The epicenter is the point on the earth’s surface directly above the hypocenter where the subsurface earthquake begins.

Smaller earthquakes that occur in the same area as the one following a larger one are called foreshocks and can occur during an earthquake. Until a major earthquake occurs, scientists cannot determine whether an earthquake is a foreshock.

The main tremor is the term used to describe the largest earthquake. Aftershocks that follow mainshocks are a given. These subsequent, smaller earthquakes occur at the same location as the primary shock. Aftershocks can last weeks, months, or even years after the main tremor, depending on how big it was.

Related article: Earthquake followed by nearly 20 aftershocks Northern California: USGS