http://news.yahoo.com/s/ap/20051203/ap_on_re_as/taiwan_tallest_skyscraper
In this item, they say that Taipei 101 Building may be causing tremors because of it's weight. Wouldn't the weight of the earth that was removed in order to build the tower far outweigh the tower itself? Even if the weight of the tower is concentrated on a slightly smaller "footprint" than the total area of the removed earth, the tower's weight still shouldn't be greater. I think this hypothesis might be a little shaky, if you'll pardon the pun! What say the experts in structural engineering and seismology?
Glenn