GPS Taking the Guess Work out of Earthquakes

How many times have we heard a weather forecast that turned out to be wrong? Having a picnic today and expecting it to be bright and sunny? Oh, too bad, here comes the rain. Forecasting is still a tricky and inexact science that is often incorrect, but having something that seems to be wrong as often as it is right is better than having something that doesn’t work at all, right?

Researchers have been working in Costa Rica and other locations to try to develop and implement a system that monitors and forecasts earthquakes for some time now. When a 7.8 magnitude earthquake hit below the Nicoya Peninsula in Costa Rica on September 5, 2012, geoscientists using GPS tracking were proven to be able to accurately forecast the location and size of a future earthquake. This is a breakthrough that can lead to using GPS technology to help people prepare for future quakes, and hopefully limit damage.

The Nicoya Peninsula Quake

Months before the September quake in Costa Rica, scientists published a prediction in June that an earthquake of this magnitude would occur along the subduction, just about where it actually occurred. Scientists were able to use GPS technology to map out how the plates have been moving over the years, little by little. There were two locations where edges of the plates had locked and appeared to be ripe for a new earthquake. With the forecast, the scientists had accurately been able to predict the location and size of the earthquake, but were still unable to know exactly when it would happen. Other scientists had predicted a similar sized temblor in the area, but thought it would occur before 2009. Similar magnitude earthquakes had struck the area in 1853, 1900, and 1950. Presently, the fault line area is continuing with what is called aseismic slip, or movement of the plates that does not create an earthquake.

Fortunately for the people living near the Nicoya Peninsula, which include a large number of expensive tourist destinations, the Costa Rican government maintains a high standard for building earthquake safe buildings. Despite the earthquake being a 7.8 magnitude temblor, there was minimal damage to the area after the quake. There were no reports of death, and only damage to structures, including the loss of a bridge.

Studying Earthquakes in Nicoya

Many of the world’s earthquakes occur under the middle of the ocean on the floor under thousands of feet of water. What helped make the area near Nicoya different is that the fault lines were closer to the surface. Thanks to erosion at sea level, the fault lines allowed researchers to find the exact location where the plates were sticking. This location in Costa Rica can be a new laboratory for research in determining how to best use GPS to track plate movement. Research can occur in relative safety near land, instead of out in the middle of an ocean.

Earthquake Terminology
Aseismic slip	Movement of plates that does not create an earthquake
Locked Fault Line	Location where plates are stuck along the fault, resulting in stored energy that later becomes the force of an earthquake
Subduction Zone	The location where two plates meet, with one plate diving under the other plate; this is the location where many earthquakes occur and volcanos are usually formed inland from them
Subsidence	Location where subduction zone sinks down
Temblor	Another name for an earthquake
Uplift	Location where subduction zone rises up

Earthquakes, GPS, and the Future

The scientists involved with this study believe that GPS technology can help accurately forecast future earthquakes. There are costs involved that might make widespread use of this practice prohibitive, but the theory should work on any subduction zone. There would be the ongoing need to monitor movement of the plates, but once a locked fault line was discovered, the GPS technology used to study and monitor the movement of the plates would make it easy to determine the location and magnitude of any future temblors. It will be important for future sites to have scientists locate the areas of subsidence and uplift around the subduction zone, as these locations will have more potential for stored energy.

Earthquakes have always been a dangerous and unpredictable natural occurrence and consequence of how our planet is designed. The current research into these natural disasters seems to allow us to know better with the use of GPS technology where these disasters might hit. The process is not designed to let us know exactly when they might hit, but as communities make plans for their buildings, it can help them to know what is possible. It can be important to help them know how much they should prepare for, whenever the inevitable occurs. The process doesn’t totally remove the guesswork, but does create a handy system that is better than just blindly guessing.

GPS Taking the Guess Work out of Earthquakes