Indonesian Earthquake Activity

[smirkymonkey]

Are there any geologists that can enlighten me on what is going on in Indonesia? Besides the quake that caused the Tsunami and the recent big one after Easter, I have noticed that there have been numerous quakes between a 5 and 6 magnitude in the region.

Are these aftershocks? Can this kind of activity trigger quakes elsewhere on the planet? It seems as though these massive plate shifts would reverberate far beyond their local area.

What do you think?

[Dogmudgeon]

1. Well, it's really quite simple ...

(Famous last words!)

Indonesia sits right next to a subduction zone. Subduction is the process of one plate "slipping" under another one. It is associated with earthquake and volcano activity. So the Indonesian subduction zone has become active.

The prospect of "triggering" earthquakes in other SZs exists, but it's not a real strong association. However, there is the fear that the increase activity will kick the supervolcano of Toba back into activity, possibly leading to an eruption. The last such eruption of Toba 75,000 years ago put 3000 cubic kilometers of "tuff" -- ash and pulverized rock -- into the atmosphere, and nearly killed off Homo sapiens.

The subduction zone off the coast of the Pacific Northwest has also become more active, but not to the degree that the Indonesian one has become.

--p!

[smirkymonkey]

2. Thanks! Great explaination!

I don't know why I am so fascinated by earth changes. I guess I am hoping that the earth will shake all the right-wingers off and restore the planet to balance! :)

[Dogmudgeon]

3. Big discussion on Supervolcanic activity

We're having a big discussion on supervolcano disasters and apocalypticism right here.

Come watch the flames! :)

--p!