112031
The dispersal index was defined by George P. L. Walker in 1973 as the surface area covered by an ash or tephra fall , where the thickness is equal or more than 1 / 100 of the thickness of the fall at the vent .
 person: George P. L. Walker
Given options, please tell me the categories of all the listed entity words.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} 
 Entities: George P. L. Walker 
Answer:
 person: George P. L. Walker