Consider the following scenario: you live near the shoreline and hear a report that an earthquake hit the ocean floor near your location. your town may experience
a. hail.
b. a tsunami.
c. rain.
d. snow.

The right answer is B.: A tsunami.
Tsunamis are (series of) relatively huge waves that come after earthquakes and similar events.

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.