Infrasound Flashcards

1
Q

Uses of infrasound

A

Forensics (Seismology)

- Monitoring Nuclear tests

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Infrasound frequency range

A
  1. 003 - 20 Hz (Below audible range)

- Characterised by low frequency, long wavelengths (100 - 10000 m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the pressure of an adiabatic gas?

A

p = k*(rho^gamma)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a ray

A

Direction acting normal to the wavefront

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a waveguide

A

A device for guiding the propagation of waves
Examples include:
- Stethoscopes
- Ear canal
- Ventilation ducts
- Layers of Earth’s atmosphere (Thermosphere, Stratosphere and Troposphere)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are pressure fluctuations generated by distant sources recorded and how are they made accurate

A

Microbarometer

  • Filters are used to remove noise from wind
  • Arrays across a region give result coherence (requires aligning to account for time difference)
  • Statistical signal processing to identify probably signals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name some sources of infrasound

A

Volcanoes, Supersonic aircraft, Earthquakes and Explosions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly