Final answer:
Tom Simkin, Lee Siebert, and Russell Blong all studied volcanic fatalities to provide valuable insights into volcanic hazards and their impacts on human safety.
Step-by-step explanation:
The individuals who studied volcanic fatalities to provide approximate answers are Tom Simkin, Lee Siebert, and Russell Blong. Collectively, they have contributed extensively to our understanding of volcanic hazards and the impact of volcanic eruptions on human populations.
These studies are crucial in developing safety and evacuation measures to protect those living near active or potentially active volcanoes.