The United States Geological Survey (USGS) has detected some 52 earthquakes so far today, mostly around the Ring of Fire. This area of the Pacific Ocean is home to 90 percent of the World’s seismic activity, including both earthquakes and volcanic eruptions. Communities in the USA – including California and Alaska – and areas of Asia and South America are at risk, but generally from small magnitude tremors. This is the case today but some parts of the Ring of Fire have seen as many as many as 11 earthquakes.
California has been struck by a total of seven earthquakes ranging from magnitude-2.7 to magnitude-3.3.
Puerto Rico saw similar activity, with 11 different activities in the region with magnitudes ranging from magnitude-3.1 to magnitude-4.7.
Alaska saw eight in total, again lower strength from magnitude-2.5 to magnitude-3.1.
The USGS has reported the strength of each quake was ‘light’, which means there will be no resulting damage.
Each earthquake struck relatively far below the surface, from half-a-mile below ground to 15 miles below.
While none of today’s earthquakes has caused major damage, three countries have seen 26 tremors in the space of just a few hours.
Just last year, the same part of the World saw 70 earthquakes hit in a 48-hour period.
This raises the question as to why exactly so many small-range tremors take place in any one area.
Why are there so many earthquakes on the Pacific ‘Ring of Fire’?
According to the USGS, 90 percent of the World’s earthquakes take place on the Ring of Fire.
The Ring of Fire is susceptible to so many earthquakes as it is intersected with most of the World’s fault lines.
Fault lines are gaps between different continental tectonic plates, which are constantly moving around.
Some tectonic plates grind together and ‘subduct’ – where one plate dips below another.
According to the USGS subducting plates are like two pieces of sandpaper rubbing together, and frequently catch on one another.
When plates catch, they act almost elastically and when they are freed, generate tremors which rock towards the surface in the form of an earthquake.
Puerto Rico, California and Alaska are all located on different subduction zones, meaning they all see hundreds of earthquakes per year.