Open AccessMicroearthquake Studies Using Sonobuoys: Preliminary Results from the Gulf of California
Author(s) -
Reid I.,
Reichle M.,
Brune J.,
Bradner H.
Publication year - 1973
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1973.tb02401.x
Subject(s) - microearthquake , geology , swarm behaviour , bathymetry , seismology , induced seismicity , oceanography , computer science , artificial intelligence
Summary We report preliminary results of the use of telemetering sonobuoy hydrophones to record small local earthquakes in the Gulf of California. Standard naval sonobuoys were deployed, and their FM radio transmissions monitored and recorded on board ship. The airgun on the moving ship was used to triangulate to obtain the positions of the sonobuoys as they drifted. In the six weeks of operation (only two of which were given priority for sonobuoy operation), we recorded numerous individual earthquakes, several earthquake swarms of 5–50 events and one swarm in the Guaymas Basin consisting of about 1000 events in a period of 6 hr. During the Guaymas Basin swarm an array of sonobuoys was deployed in the epicentral region shortly after the beginning of the swarm, and source locations have been determined to within 2 km. With further refinements of navigation and bathymetry we expect the source location error to be reduced further. Such accuracy has never before been achieved for this type of sequence and compares favourably with the accuracy of after‐shock locations on land. The events in the Guaymas swarm were located in a 2 km wide graben associated with the Guaymas Basin spreading centre.