Are earthquakes becoming more frequent?

The two high-intensity earthquakes in Nepal in the past fortnight have spurred discussion on whether such occurrences have become more frequent over the years. Data on the number, magnitude and resultant death toll of earthquakes over the last century shows that while the number of earthquakes per year has indeed seen an increasing trend, the proportion of high-intensity quakes has been decreasing over the years.

Data compiled by the US government’s National Oceanic and Atmospheric Administration shows that the number of earthquakes per year has seen significant variation, but the overall trend shows an increasing frequency. Now, it must be kept in mind that a century is minuscule when compared with geological timescales that run into millions of years and so this doesn’t necessarily point towards a geological change. One likely explanation for this is that earthquake detection centres have become more advanced and span the globe, and so are more likely to pick up on seismic activity.

Along with an increase in the number of earthquakes, the data shows a decreasing trend when it comes to the frequency of high-intensity quakes (above 6 in magnitude). This suggests that there has been an increase in the frequency of low-intensity tremors around the globe, another thing which points to better equipment rather than anything else.

Earthquake-resistant technology has become more advanced, especially in areas such as Japan and California where high-intensity earthquakes are frequent. The fact that 165,681 people have died due to 61 earthquakes in Japan since 1900 compared with a whopping 316,000 deaths in Haiti due to a single earthquake in 2010 underscores the importance of developing and adopting earthquake-resistant buildings and heightened safety measures in urban areas around the world.