Earthquake + Water = Tsunami

I have learned about earthquakes (those on land and shifting underwater plates) in the past two years as my daughter has studied plate tectonics several times. I have learned that the moving plates (this fault has subduction) can create volcanos, canyons or, if in water, tsunamis, even if there has been no movement for over 100 years. I read, with sadness and horror, of the lost lives and the large number of children that were killed or have been orphaned from this natural event. I read that the areas have been impacted ecologically by development, mostly from shrimp farming and some tourist resorts, removing the natural barriers of the coral reefs and mangroves. (I don't know what a mangrove is but assume it is a tree.) Any animals that reside at the waters' edge are accustomed to storms, and have a built-in "warning system." Sadly, the humans did not have a warning system, though an earthquake under the sea commonly results in a tsunami. The ten affected nations are predominantly poor, without the economic means to develop seismic monitoring and tracking systems along the scale of that which the Japanese have created. So, lives are lost, and the trickle down effect will be felt around the world, as will the sadness for those who have lost their family, homes and livlihoods. With cellphones so prevalent in Asia, replacing the infrastructure of a traditional phone network, a sort of informal, cellphone-based, "telephone tree" might have saved some lives if some calls had been placed in the one hour between the earthquake and waves hitting southeast Thailand.