Earthquakes don't hit my neck of the woods too often - the Rockies - and when they do, you'd be hard-pressed to notice them.
However, the rest of the world is not so lucky. A lot of people have developed an intense interest in earthquakes for very good reasons - they could be subject to a real whopper of one some day.
The above video from the Pacific Tsunami Warning Center (PTWC) is, as of this posting, up-to-date with all recorded earthquakes of the previous four months. Note that the flashes indicate both depth (color) and magnitude (size of flash). Depth is important for a number of reasons, not least is how the resulting tsunamis form.
There are a few obvious patterns that you will notice from watching the animation:
- The earthquakes are clustered along fairly obvious and well-known fault lines where tectonic plates meet and grind against each other;
- The Asian/Alaskan/North American/South American ring is known as the "ring of fire" for a very good reason;
- The mid-Atlantic trough is a real hotbed for earthquakes, though nobody ever mentions them; and
- Earthquakes inside large landmasses are fairly rare except along fairly obvious (once you notice the patterns) points.
Looking at the location of the quakes, you better appreciate that it is only a matter of time before a nice big one hits California again. This year, the big ones were in South America and New Guinea, but that luck could run out at any time.
Naturally, this kind of interpretation would have been impossible before the 20th Century, and even now it only is so obvious to the casual observer because of the power of animation. Easy for me to say now. It took a lot of expense and effort to develop the resources and equipment and understanding to plot this easy-to-see data.
Oh, and April is Tsunami Awareness Month!!!!!!! Posting this video is my attempt to do my part to help the cause.
From the PTWC youtube page:
Earthquakes happen every day, and as this animation shows, small ones happen more frequently than once per hour. Moderate-to-large earthquakes are less common, however, perhaps 1-2 per month on a long-term average. Therefore April 2014 was unusual not in the total number of earthquakes that occurred but in how many moderate and large ones happened, and PTWC had to issue official message products for 13 different earthquakes in that month for earthquakes with magnitudes of 6.5 or higher, easily a record for this institution. Of those 13, PTWC issued tsunami warnings for 5:
1 April, M8.2, northern Chile
3 April, M7.8, northern Chile
12 April, M7.6, Solomon Islands
13 April, M7.7, Solomon Islands
19 April, M7.8, Solomon Islands
This animation shows all earthquakes on earth so far this year in sequence as recorded in the USGS's NEIC database (available at earthquake.usgs.gov). Note the typical level of activity through March. But starting with the 8.2 magnitude earthquake in northern Chile on April 1, the rest of the month saw 12 more moderate-to-large earthquakes mostly in Chile and the Solomon Islands but also in Nicaragua, Mexico, Canada, and even the south Atlantic Ocean. The animation concludes with a summary map showing all of the earthquakes in this four-month period.