Following the recent spate of earthquakes in California, which were two of the biggest earthquakes in decades and resulted in a huge surface rupture, as detected by satellite images, I was interested in visualizing earthquake activity, not just by geographical region, but also through time.
For the purpose of this post, I only considered earthquakes measured by the Richter scale or Local Magnitud ML from the Global catalog of earthquakes by the Humanitarian Data Exchange.
We can see clearly enough that most of the higher-magnitude earthquakes occur along the Pacific Ring of Fire - the west coast of NA & SA, and along the western pacific coast, a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and plate movements.
The Western Pacific Coast seems to be the most consistently affected area through time.
It would be interesting to compare this data - particularly the quakes happening far out at sea - with tsunami activity along the coasts.
Level 8 on the Richter Scale is defined as severe - Major damage to buildings, structures likely to be destroyed. Will cause moderate to heavy damage to sturdy or earthquake-resistant buildings. Damaging in large areas. Felt in extremely large regions.
We can see from the map above that these do not occur often.
Nearly all occur along the Pacific Ring of Fire.
The number of earthquakes seems fairly consistent through time.
The number of extreme magnitude quakes has increased in the last 20 years.
Only 2 earthquakes in our timeline have breached 9.0 on the Richter scale: