Anatahan Volcano Update
Anatahan Volcano Update for April 29, 2004
Submitted Thursday, April 29, 2004 at 0830 local Anatahan time
Anatahan seismic activity increased abruptly on April 24 to a high level
unseen since summer 2003. and a moderate eruption began producing steam
and ash to ~2,000 ft (600 m). An overflight on the 24th reported the
probable presence of fresh lava within the inner crater. The
seismicity level increased further on the 24th and 25th to a new high
similar to that of the eruption of mid-June 2003. On the April 26, a
"cow-pie"-shaped dome was observed within the inner crater. Early today
the seismicity level increased still further to a new high between 1300
and 1600 UTC (2300 4/28 and 0200 4/29 CNMI) and then leveled off again.
The new high is about 25 percent more energetic than previous the high
of April 25. An overflight on 4/26 observed regular puffs of
yellow-brown steam and ash at 1/2-2 minute intervals rising to ~2,000 ft
(600 m) but that could be higher today with the increased seismicity
level and could increase further yet with little or no warning.
The Emergency Management Office, Office of the Governor, CNMI, has
placed Anatahan Island off-limits until further notice and concludes
that, although the volcano is not currently dangerous to most aircraft
within the CNMI airspace, conditions may change rapidly, and aircraft
should pass upwind of Anatahan or >30 km downwind from the island and
exercise due caution within 30-50 km of Anatahan. Contact persons:
Juan Takai Camacho, Geophysical Seismic Technician, EMO Saipan; tel:
(670) 322-9528, fax: (670) 322-7743, email: juantcamacho@hotmail.com
Ramon Chong, Geophysical Instrument Specialist, EMO Saipan; tel: (670)
322-9528, fax: (670) 322-7743, email: rcchongemo@hotmail.com
Frank Trusdell, Geologist, USGS; tel: (808) 967-8812, fax: (808) 967-8890,
email: trusdell@usgs.gov
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