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Marine Seismology : A significant proportion of the heat transferred from the 

 earth's interior to the ocean/atmosphere system is thought to occur through 

 volcanic activity on the deep sea floor along the mid-ocean ridges. Currently 

 there is very little understanding of the extent, duration and nature of such 

 activity, or the significance of sea floor volcanism in perturbing the global 

 environment. 



The first demonstration that Navy lUSS arrays could alert geophysicists 

 to volcanic activity on the mid-ocean ridge occurred on June 26, 1993. 

 Scientists working under the NOAA VENTS Program utilized acoustic data from 

 several remotely located lUSS surveillance arrays in the Pacific to identify an 

 earthquake swarm (about 30 per hour) on a supposedly inactive segment of the 

 Juan de Fuca Ridge. Using the signals detected on the lUSS receivers to 

 localize the site, two research vessels subsequently discovered a "megaplume" 

 of heated water and a seven-kilometer stretch of fresh lava along the ridge. 

 This example Is directly analogous to the traditional ASW role of lUSS for 

 detection, localization and cuing. In addition, the monitoring of acoustic phases 

 of mid-ocean earthquakes (i.e. "T-Phases") permits the detection of much 

 smaller earthquakes than can be detected using the land-based geophysical 

 detection network. 



Fisheries Enforcement : By using the sophisticated capabilities of lUSS to 

 detect and classify signals in the ocean, it was suggested that the system could 

 possibly be used to detect and classify fishing vessels which are violating laws 

 and regulations, such as the Driftnet Fisheries Enforcement Act. With limited 

 resources available for enforcement, finding violators can be a very difficult 



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