Return to COAXIAL home page.
Perhaps the most impressive demonstration of the utility of the SOSUS hydrophone
network for the monitoring of oceanic seismicity occurred in June and July of
1993. A swarm of small events was detected in real time, and was determined
to be occurring on the Juan de Fuca Ridge crest just north of Axial Seamount.
The source area moved about 40 km along the ridge crest in the span of a few
days, suggesting a magma intrusion. The extra activity can be seen in the earthquake
map for the second quarter of 1993, at 130° W, 46.5° N. Fortuitously,
the swarm occurred in summer, and research ships were scheduled to work in the
vicinity. The Canadian ship Tully, and the NOAA ship Discoverer were rerouted
to investigate the site. Plumes of heated water and subsequently fresh lava,
were discovered at the site.
Animations of the earthquake swarm show the movement of the source
locations along the segment. Note that you will need an MPEG viewer for
your Web client, and that the files are about 1800k and 700k in size
respectively.
Address inquiries to:
Chris Fox - Principal Investigator (christopher.g.fox@.noaa.gov)
Tony Schreiner - Analysis, and Modeling
Bob Dziak - Analysis and Event Detection (robert.p.dziak@noaa.gov)
Andy Lau - Data Processing Methods (andy.lau@noaa.gov)
Haru Matsumoto - Engineering (haru.matsumoto@noaa.gov)