That is called a transform fault boundary :)
A tsunami is a earthquake underwater
B two plates slide past each other
The Indus Valley Civilization(IVC), was an ancient civilization thriving along the lower Indus River and the Ghaggar River-Hakra River in what is now Pakistan and western India from the twenty-eighth century B.C.E. to the eighteenth century B.C.E. Another name for this civilization is the Harappan Civilization of the Indus Valley, in reference to its first excavated city of Harappa. The Indus Valley Civilization stands as one of the great early civilizations, alongside ancient Egypt and Sumerian Civilization, as a place where human settlements organized into cities, invented a system of writing and supported an advanced culture. Hinduism and the culture of the Indian people can be regarded as having roots in the life and practices of this civilization
Many people decided to move from more rural areas that offered land and space for farming to cities that had factories and offered job opportunities