answered
(By alcohol abuse, I hope you mean using alcohol in excess. If not, then I'm afraid this might not help much)
  • Peer Pressure (trying to act "cool" or show off in front of others)
  • Acting before thinking
  • Parents acting as bad role models (if your father/mother was an alcoholic, you have an increased chance of becoming … Read more
answered question
They HAPPEN DUE TO SEISMIC UNDERWATER ACTIVITY; in other words, when an earthquake happens underwater, and tectonic plates slide on top each other, it causes waves to form. When plates collide, they get squished to form trenches or mountains. The water above gets squished too, but since its water, it rebounds in waves, causing tsunamis.