The Ship Pictured to the left is a very special ship.  It is a Catamaran that is used for special Geophysical Oceanic Scientific Investigations. I was asked to help test and put to "sea trials" a new system that will help JAMSTEC perform subsurface seismic reflection surveys to determine the location of off shore fault zones near and around the Japanese Islands.
During the 24 hour test, the Kayio(Pictured left) shot 453 seismic records, shooting every 90 seconds.  This over an approximate 50 Nautical Mile traverse.  The data looked very good.

These two records are actually one single record, split in two parts.  The total record is about 15 seconds long.  You can see each event as recorded by the Kayio' system.   The Ocean Bottom is at 6 seconds, the second event from the top here on the record displayed at the left.  You can also see events even down to some 13 seconds.   The event near 13 seconds to the right is very probably the Ocean "Moho" discontinuity.