This is liquefaction, which occurs most often in backfilled sea reclamation areas, but can happen in any place with a high water table. It is a big problem in places like Berkeley and SF, California and all throughout coastal Japan. It is what caused so much damage in the Marina in SF in ’89, Kobe and downtown Christchurch, too.
Liquefaction also causes anything buried with air in it to float to the surface like coffins, partially empty fuel tanks, and as seen here, sewer systems:
Since the 9.0 earthquake, there have been TWENTY quakes of level 6.0 or above – and ONE HUNDRED quakes of level 5.0 – 6.0 that are able to knock down a chimney.
This has been a long period of trauma for the Japanese people, something like a siege or war, especially with the nuclear problems and then the cold and snow. However, if the tsunami had hit Tokyo, the mortalities and damage would likely have been far greater.