Today I read about the recent earthquake and tsunami in Indonesia. It was caused by the eruption on the younger volcano Anak Krakatau. Also, the country was hit by another tsunami just three month’s prior.
Which got me thinking, why does this country get so many quakes,and tsunamis ? And..how large is this country ? Never thought about it geographically. So I looked around.
Indonesia is one heck of a country, split across five different larger islands, but comprising of upto 18,000 islands ! Managing one landmass is difficult enough, but here they have a political and geographical nightmare to manage, with so many different ethinicities and cultures ! All in the largest sesimically active regions on this planet.
This is what I found on the USGS site.
Which country has the most earthquakes?
The answer to this question is not as straightforward as it may seem. In order to most accurately answer it, we will rephrase the question four different ways:
- For which country do we locate the most earthquakes? Japan. The whole country is in a very active seismic area, and they have the densest seismic network in the world, so they are able to record many earthquakes.
- Which country actually has the most earthquakes? Indonesia is in a very active seismic zone, also, but by virtue of its larger size than Japan, it has more total earthquakes.
- Which country has the most earthquakes per unit area? This would probably be Tonga, Fiji, or Indonesia since they are all in extremely active seismic areas along subduction zones. The sparse seismic instrumentation in those areas doesn't allow us to actually record all the smaller earthquakes.
- Which country has the most catastrophic earthquakes, or which has had the most damage and fatalities? Both China and Iran are in seismically active areas, have very long historical records, and have had many catastrophic earthquakes. Turkey is also worth mentioning in this category.
That is a lot of earthquakes, and a miracle that these places still exist and are able to govern themselves all the while standing on plates floating on molten lava.
And this is Indonesia ! The area marked in red. Imagine governing this landmass, when there are average 4 earthquakes per year in the country.