A tsunami.Because tsunamis are unpredictable in a way, a body of water that is very vast can cause an uprising of water. As for instance, if I lived in Hawaii, and their was a tsunami coming forth from each side, it would be a problem.
Mostly the electrons will determine the reactivity
P = pressure, V = volume, T = absolute temperature k = constant.
As a base is added to an acidic solution, the H+ ions in solution that make it acidic are slowly neutralized into water (via OH-, the base). As these ions are converted into water the concentration of them decreases, so the pH decreases, as they are directly related.
Hope this helps!