As they are connected to deep sources of the water inside earth thus they are more senstive to any movement then surface water.
 during an earthquaqe it can be used as a alarm sign and preventive measures can save a lot of life thus the water being deep enough it can create a more faster than surface water and gives us a little time.

can u make it a bit lon
xplain it
U did it here aryan .thx ur the best
Make it long plz man