Could somebody explain fracture throughly? it is on the rocks and minerals topic

Atsunami usually is the result of a. a nearby underwater earthquake. b. the winter monsoons. c. seismic activity in the eastern pacific ocean. d. hurricane-force winds.

Volcanic irruption is most likely to be violent when a) volcanoes near to the sea b) the neck of the volcano is sealed by a plug c) the lava is viscous d) the lava reaches the surface through a fissure e) the volcano is on the ocean floor

Which of the following best summarizes the point of agreement?