File Size

Sound Duration

Description

20

0:34

Navy Low Frequency Active Sonar (LFA) recorded in 1994 off Washington state while the Navy source ship was transmitting off San Diego about 1000 miles distant (spectrogram shown in corner).

21

0:25

When a household light bulb is dropped overboard with a rock attached, it will self-implode at a depth of about 100 meters, producing an impulsive sound.  This recording is of such an implosion in 2400 m water depth where the echoes are distinctive corresponding to the water depth and hydrophone depth. Ocean acousticians sometimes use this technique as an inexpensive sound source.

22

1:00

The sound of the 52 m NOAA research vessel MacArthur at about 3/4 mile range in calm seas as recorded on a sonobuoy.

23

1:02

The sound of a large merchant vessel at a few miles in choppy seas as recorded on a sonobuoy.

24

0:38

Two microearthquakes (about magnitude 1) at shallow depth near the Blanco transform as recorded on a sonobuoy, 5/12/97, 13:01, 44º 18' N 126º 58' W.

25

1:46

Counter calling from unidentified species, Bering Sea, 57º N 164º W, stereo is two sonobuoys 7 miles apart, in the presence of gray whales, seals had not been seen in the area, someday perhaps we will learn what makes these sounds