|Not a tsunami, but you get the idea... (credit Wikimedia Commons)|
I wanted to provide a quick look at some of the effects of earthquakes and tsunami on freshwater resources in affected regions. Usually these things are not considered until the relief and recovery effort is underway, but they are considerations right from the start of the natural disaster to keep in mind. Specifically, there are four impacts to be aware of:
|credit Fukushima Minpo/AFP/Getty Images/Boston Globe|
|credit Kyodo News/Associated Press/Boston Globe|
|credit Saitama Shimbun/Associated Press/Kyodo News/Boston Globe|
 Dam failures: according to HydroWorld, "a dam the northeast Fukushima prefecture of Japan broke and homes were washed away, Kyodo News reported" [links added] following the largest of the off-shore earthquakes last night. For masonry dams, such as the iconic concrete arch-gravity dams like Hoover and Glen Canyon in the American Southwest, the likelihood of catastrophic failure in an severe earthquake event is high. For such dam types, shaking can cause massive cracks in both the dam face and its abutments, allowing the reservoir water to pour through in massive quantities over a short time and removing the standing remainder of the dam entirely. For rock-fill and earth-fill embankment dams, which are far more common throughout the world, the process of earthquake liquefaction is again a possibility for those soils that are always in contact with the reservoir waters. Not only can the failure of the dam lead to downstream flooding and fatalities, but the reservoir itself is lost in the process, making life far more difficult on the survivors as well. The population's dependable source of freshwater, for domestic and agricultural and industrial uses, disappears entirely, and any flood protection provided by the reservoir and dam are foregone for the time that is taken to engineer and build a replacement structure.
Author's note: I owe many thanks to @oocscience for our pre-quake discussion that helped me line out a few of these issues, though at that time I was thinking of another post entirely...we were indeed messing with fate.