Tuesday, May 29, 2012
Northern Italy Crumbles
This is where I so want the quality of seismic maps I get for the States. I look at this area, and it reminds me of Christchurch. Basically, it is a lowland where there shouldn't be one, a bit of an anomaly. It is topography that must be defined and formed by earthquakes. The mountains are also formed by earthquakes, and the trick is to see whether it is still an active process. In Japan, the big earthquake reinforced the topography, the lowlands went down and the highlands went up.
Now, I suspect these lowlands are perfectly stable for hundreds of years, and then they start to move in a series of earthquakes. This is different from many places where all the land moving is done with a big M9. Here, the geometry constrains having a single big earthquake (fractal scale limits), and all the action must be done with M6's.
Unfortunately I don't have any access to better data, either for Christchurch or here. We shall just have to wait.
Update: You can see here what they would call the 'foredeep' of the Alps. It has very little seismicity, but that must fill in one day.