What is a rift lake?
Rift lake
{'answer_start': array([15]), 'answer_text': array(['a lake formed as a result of subsidence related to movement on faults within a rift zone'],
      dtype=object)}
A rift lake is a lake formed as a result of subsidence related to movement on faults within a rift zone, an area of extensional tectonics in the continental crust. They are often found within rift valleys and may be very deep. Rift lakes may be bounded by large steep cliffs along the fault margins.