Earthquakes, usually they happen without warning. In most of the cases there is no way to predict where and when they will strike. They come from deep inside the earth, though usually short-lived, can leave devastating destruction in their wake. Disasters are part of the reality of the world but natural hazards become disasters only when they collide with people. Now Italian scientists say the effects of strong earthquakes can be predicted seconds before the destruction occurs.
Though its hard to quickly and accurately assess what needs to be done and to help yourself get out of the deadly situation. Researchers in Italy analyzed seismic signals from more than 200 moderate to strong earthquakes in the Mediterranean region, ranging from magnitude 4.0 to 7.4. They found that the initial waves, called primary waves travel at about 4 miles per second, covering about 40 miles in 10 seconds where as Secondary waves that are typically more damaging, move at about 2.2 miles per second.
This means the residents of a city located 40 miles from an epicenter would have about 15 seconds to prepare for impact if a sufficient automated warning system is established.
One need look no further than the horrible devastation that an earthquake can cause. Since it takes time for the earthquake to be felt over a wide area, sensors close to the epicenter could alert those more distant, providing many tens of seconds of advance warning. This might be enough to get situated in a doorway, under a table, or well clear of falling building debris.
It would be useful to know how large the hot spots are, but this is promising research for the potential beneficiaries like hospitals, fire departments and tsunami warning centers, all of which might be cut off from communications by the damage caused shortly after a warning is issued.