A transform boundary happens when two plates slide past one another. Transform boundaries cause earthquakes when one plate slips past another plate! However, the most popular transform boundary is the Pacific plate is sliding past the North American plate forming the San Andreas Fault in California. The strongest and most famous earthquake along the San Andreas fault his San Francisco in 1906, but as a result, around 600 people died.
Watch 0:00 - 0:49 to see how transform boundaries work!