Question

when an earthquake occurs, energy radiates in all directions from its source. the source is also referred to as the __________. seismic zone internal point focus epicenter most of our knowledge about earths interior comes from __________. drill holes deep mine shafts volcanic eruptions seismic waves the instrument that records 2 points 2 points * 2 points

Explanation:

1. The point within the Earth where an earthquake originates and energy radiates from is called the focus. The seismic zone is an area prone to earthquakes, an internal point is a general term not specific to earthquake - source, and the epicenter is the point on the Earth's surface directly above the focus.
2. Seismic waves are the main source of our knowledge about Earth's interior. Drill holes and deep mine shafts only reach relatively shallow depths. Volcanic eruptions provide some information but are not as comprehensive as seismic waves for understanding the entire interior structure.

Answer:

1. C. focus
2. D. seismic waves