4690
A geological tremor could cause this natural levée to give way , allowing water to rush into downstream villages all the way into Nigeria and allowing large amounts of carbon dioxide to escape .
 location: Nigeria
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 location: Nigeria