Answer:
1. A compass measures Earth's magnetic field, determining its north pole alignment with the geographic south pole, aiding navigation and determining the direction of the Earth's magnetic field.
2. The four pieces of evidence of Earth's layers are:
- Seismic waves: Seismic wave analysis reveals Earth's layers, revealing distinct layers with different properties as they travel through the Earth.
- Rock samples: Geological studies reveal variations in rock types, densities, and compositions from deep drilling or volcanic eruptions, supporting different layers.
- Earth's gravity: Variations in gravitational pull across the Earth's surface indicate variations in density and mass distribution, consistent with different layers.
- Earth's magnetic field: Earth's magnetic field behaviour, including anomalies and variations, indicates layers, including the outer core, responsible for generating the magnetic field.