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CoAxial Eruption, 1993

tremor spectrogramThe CoAxial Segment had a well-documented dike injection and eruption episode in June-July of 1993 which was detected and monitored by the NOAA/Navy SOSUS real-time T-wave monitoring system. Two "event plumes" were found over the axial valley centered around 46° 30'N where the T-waves had concentrated during the latter part of the episode. This site (which subsequently was known as the Flow site) became the target for dives with the Canadian remotely operated vehicle ROPOS off the NOAA R/V DISCOVERER in mid-July, 1993, during which a fresh, venting lava flow 2.5 km long was discovered, mapped and sampled. The lava flow was erupted on a ridge just north of an older volcano cone on the median volcanic ridge. Extensive venting was also found southward from the cone for about 4 km within a small graben.

Visit the CoAxial eruption site for more information.

Click on spectrogram for full-sized image.