14 DAY TRIAL // According to the results of a new analysis conducted by a Unites States Geological Survey (USGS) scientist, it would seem that the large earthquakes which affected the planet over the past couple of years are not indicative of a general trend towards more powerful tremors.
In other words, the magnitude 7.2 tremor that hit Turkey on October 23 and magnitude 9.0 tremor that devastated Japan on March 11 are instances of random, natural occurrence. The results were derived from a study of tremors that affected the planet over the past 110 years.
USGS seismologist Dr. Andrew Michael analyzed global seismic records spanning back more than a century, and was unable to find any statistical correlation to prove that tremors occurring over the past few years are starting to become more powerful.
The investigator used three distinct statistical tests to conduct the analysis. He determined that the random fluctuation we are currently experiencing makes a lot of sense, once researchers take local aftershocks into account as well.
If these natural disasters were to be related to each other, Michael explains, then the data should have revealed a clustering pattern in the intervals between major tremors. Such a connection could not be extracted from available data.
“Large earthquakes, in statistical terms, do not happen very often, even though they are noteworthy for their enormous consequences. In events that do not happen very often, random processes are highly variable and may appear clustered even if they are not,” Michael explains.
“While the probability of future large mainshocks has not increased, neither has it decreased,” he adds. The scientist also developed a specific earthquake-triggering statistical model, which was meant to determine whether global seismicity increased after large tremors.
The new work again draws attention to the perils of using only short-term records as predictors for future seismic risks. Michael says that experts should always use long-term records when trying to discover any type of trends.
“This research is a good example of how science can empower our decisions with knowledge rather than fear,” explains the director of the USGS, Marcia McNutt.
“Those who live in earthquake country should work to make their surroundings as safe as possible and know what to do if an earthquake happens regardless of how quiescent or active the rest of the planet may be,” she concludes.