The latest earthquake ‘swarm’ in Southern California was comprised of more than 400 minor earthquakes in just a few days. It leaves most of us to wonder if it is a sign of a larger earthquake to come. So who or what is keeping an eye on things for us? How far have we come in detecting and predicting earthquakes?
We have come along way in seismic research over the years and scientists and engineers at the California Institute of Technology, USGS Pasadena, UC Berkeley, the Swiss Federal Institute of Technology, and the University of Southern California have been hard at work on a Earthquake early warning system (EEW). This early warning system works by detecting the first bit of energy that radiates from a particular earthquake, known as P-wave energy. This P-wave energy is used to pinpoint the location and magnitude of the earthquake.
In demonstrations of the system, software sounds an alarm and then shows the center of the earthquake. Then a simulated wave of energy is displayed, indicated by a circle increasing in size to show where the energy is as it travels away from the epicenter. The software also displays the magnitude and indicates when shaking should end. This EEW system is still a prototype and would need greater funding in order to to be more accurate and reliable for use in California and the Pacific Coast. You can see this software demonstration in action at the bottom of this page.
You could use the information gathered by these systems to try to decipher patterns in the Earth’s seismic activity to determine where more earthquakes will occur but this system is mainly built around earthquakes that have already occurred. What scientists would really like to achieve is the abbillity to accurately predict seismic activity before it happens.
A publication in the Journal of Zoology indicated that the common toad known as (Bufo bufo), was able to predict seismic activity many days in advance of a an actual earthquake. The toads will abandon their breeding site before an earthquake occurs. Researchers believe that the toads are able to detect some subtle changes in their surrounding environment shortly before an earthquake occurs.
Some research has gone into detecting some of these changes including air ionization, magnetic pulsations, and infrared radiation emitted near the earthquake location, but it is difficult to gain accurate information from these potential warning signs as there are many factors involved that disrupt and interfere with readings.
Currently, scientists use educated guesses based on the history and current seismic activity of specific regions along with the general movement of tectonic plates. These predictions are not very precise and usually get compiled into probability percentages. It’s not to say we haven’t become better at predicting them, it’s just that we can do a lot better.
What is important to take away from this is that at this time we can not accurately predict earthquakes, so it is important to prepare for them. You should always keep an emergency kit in your home. Place your kit in a well known location thats easy to get to. Your emergency kit should contain food,water, first aid supplies, flashlights, a radio and spare batteries. These supplies should be able to sustain you and your family members for at least 72 hours.
Make sure shelves are secured and always place heavy objects on lower shelves. Do not place heavy objects like large mirrors above your bed or places people will sit. Remember that it’s not the earthquake itself as much as it is the objects around you that are a dangerous when an earthquake occurs.
Useful websites with more information on this subject:
For more information on what to do before, during and after an earthquake please visit the FEMA website here.
You also get the latest updates on seismic activity through the USGS website here.
Apps you can download to track seismic activity:
If you’re looking for good mobile app that will notify you of seismic activity you can download “EarthQuake Alert!” for Android. Information about this app can be found here.
For iOS devices you can try Earthquake! The description can be found here.