What was Mohorovičić's observation?(1 point)

Question

Responses

Seismic waves penetrated all Earth's layers.
Seismic waves penetrated all Earth's layers.

Seismic waves could not go through the brittle crust.
Seismic waves could not go through the brittle crust.

Seismic waves travelled at constant speeds.
Seismic waves travelled at constant speeds.

Seismic waves travelled at varying speeds.

Answer 1

Seismic waves travelled at varying speeds.