What was Mohorovičić's observation?(1 point)

Question

Responses

Seismic waves travelled at varying speeds.
Seismic waves travelled at varying speeds.

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

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.

Answer 1

Mohorovičić's observation was that seismic waves travelled at varying speeds.