Lecture 1 Flashcards
What is the lithosphere made up of
Crust, Moho, Upper Mantle
Definition of Seismic Waves
Parcels of elastic strain energy that propagate outwards from a seismic source
What does seismic velocity depend on?
Velocities depend strongly on the elastic properties and the density of the rock that the seismic wave is travelling through
Define potential fields
The study of the earth gravity and magnetic fields and their perturbations at the Earth’s surface
Name what the Earth’s interior is made up of
Crust Moho Upper Mantle Lower Mantle “D” layer - discovered from seismology Outer core - elastic, propagates elastic waves Solid-Liquid boundary Inner Core -more elastic
Geophysical rock properties
Density
Theological
Thermal conductivity
Magnetic properties
How many seismometers are used when recording earthquakes
3
Records N/S, E/W and up and down.
Larger seismometers record what
Higher waves
Smaller seismometers record what
Lower waves
Broadband seismometers
Get large range of frequencies
Type of Seismic Waves
Body Waves:
- Primary Wave
- Secondary Wave
Surface Waves:
- love wave
- Rayleigh wave
Can S waves propagate through fluids?
No
Define Epicentre
The point on the Earth’s surface that is directly above the the hypocentre where the earthquake begins
Define Hypocentre
The point within the Earth’s interior where an earthquake originates
PREM
Preliminary Reference Earth Model
One dimensional model representing the average Earth properties as a function of planetary radius
